No full-text available
To read the full-text of this research,
you can request a copy directly from the author.
The ring test: a quantitative method for assessing the ‘cataleptic’ effect of cannabis in mice
British Journal of Pharmacology
Abstract
A bioassay for cannabis, called the ring test, has been developed in which the percentage of the total time spent on a horizontal wire ring during which a mouse remains completely immobile is recorded.
. The effect of cannabis on mobility is a dose‐related, graded response.
. Threshold doses of cannabis extract are 12·5 mg/kg when injected intravenously, and 100 mg/kg when injected intraperitoneally or subcutaneously.
. The method provides a measure of the ‘cataleptic’ effect of cannabis. Chlorpromazine in doses of 1 mg/kg upwards also produces the effect but barbitone does not.
. It is concluded that Δ ¹ ‐tetrahydrocannabinol (Δ ¹ ‐THC) is largely responsible for the effect of cannabis extract on mobility; the potency ratio of Δ ¹ ‐THC to cannabis extract is between 10 and 20. Δ ¹ ‐Tetrahydrocannabidivarol (Δ ¹ ‐THD) also affects mobility but is less active than Δ ¹ ‐THC. Cannabidiol has no effect when injected intraperitoneally in doses up to 100 mg/kg.
... Once the animal attained stage IV or the deepest attainable stage, it was subjected to the "ring test" of Pertwee (1972) 13 , where the animals were placed gently on the upper ring (40 cm hitch) of the cataleptic stand" in a manner that the paws rested on the ring, their hand facing away from the vertical stand. The animal was closely observed for a total period of 5 minutes during which the animal remained perfectly immobile (the cessation of the stout and wiskering movements taken as index) with the exception of respiratory excursion and a typical sagging movement, was recorded to the nearest second with a stop watch. ...
... Once the animal attained stage IV or the deepest attainable stage, it was subjected to the "ring test" of Pertwee (1972) 13 , where the animals were placed gently on the upper ring (40 cm hitch) of the cataleptic stand" in a manner that the paws rested on the ring, their hand facing away from the vertical stand. The animal was closely observed for a total period of 5 minutes during which the animal remained perfectly immobile (the cessation of the stout and wiskering movements taken as index) with the exception of respiratory excursion and a typical sagging movement, was recorded to the nearest second with a stop watch. ...
... body wt. during pilot studies, the "ring test" of Pertwee (1972) 13 was performed, and the results are tabulated in Table - Table -7 14 . Paucity in the previous literature regarding KF alkaloids prompted us to investigate the effects of the extracts of this plant on cardiovascular system, respiratory system, central nervous system as also effects on skeletal and smooth muscle preparations, as other members of Apocynaceae family have been reported to induce varieties of pharmacological effects like depression of the CNS and CVS, vasodilatory, local anaesthetic and others 1 . ...
Drugs bearing indole alkaloids are known to produce important pharmacological effects. Kopsia fruticosa (KF), member of thee Genus Kopsia containing four indole alkaloids possesses central nervous system (CNS) pharmacological effects. This study was conducted to explore the CNS effects of KF in rodents. Materials and Methods: The propylene glycolic solution (KF1) and aqueous solution (KF2) were prepared from the dried extract of the leaves of KF. Evaluation of hexobarbitone induced sleeping time in mice, analgesic effect by Tail flick response on thermal stimulus in rats, locomotor activity by Spontaneous motor activity and rota rod method in rats, sedative ataxic score by inclined plane method in mice and behavioural activity by Gross behavioural effects, Conditional Avoidance response, and cataleptic effects in rats were performed at 2, 4, 8,16 mg/kg of body weight respectively. Results: KF1 reduced the spontaneous locomotor activity and exploratory behaviour in mice (p<0.001-0.01) more than KF2. KF1 in all doses potentiated the hypnotic dose (p<0.001) of hexobarbitone and sub-hypnotic dose (upto 80% potentiation) of hexabarbitone as compared to only 40% potentiation by KF2. Anti-nociception effect was found to be absent at all doses. KF1 possesses moderate sedative ataxic effect (p<0.001) and KF2 at 8mg/kg b.w. revealed mild effect (p<0.05) when compared to pentobarbitone. KF1 induced a moderate degree of catalepsy and potentiated cataleptic and sub-cataleptic doses of haloperidol at all doses (p<0.001). Conclusion: The present study has revealed that the propylene glycolic extract of the leaves Kopsia fruticosa possesses profound action on the CNS thereby paving the way to further research.
... Once the animal attained stage IV or the deepest attainable stage, it was subjected to the "ring test" of Pertwee (1972) 13 , where the animals were placed gently on the upper ring (40 cm hitch) of the cataleptic stand" in a manner that the paws rested on the ring, their hand facing away from the vertical stand. The animal was closely observed for a total period of 5 minutes during which the animal remained perfectly immobile (the cessation of the stout and wiskering movements taken as index) with the exception of respiratory excursion and a typical sagging movement, was recorded to the nearest second with a stop watch. ...
... Once the animal attained stage IV or the deepest attainable stage, it was subjected to the "ring test" of Pertwee (1972) 13 , where the animals were placed gently on the upper ring (40 cm hitch) of the cataleptic stand" in a manner that the paws rested on the ring, their hand facing away from the vertical stand. The animal was closely observed for a total period of 5 minutes during which the animal remained perfectly immobile (the cessation of the stout and wiskering movements taken as index) with the exception of respiratory excursion and a typical sagging movement, was recorded to the nearest second with a stop watch. ...
... body wt. during pilot studies, the "ring test" of Pertwee (1972) 13 was performed, and the results are tabulated in Table - Table -7 14 . Paucity in the previous literature regarding KF alkaloids prompted us to investigate the effects of the extracts of this plant on cardiovascular system, respiratory system, central nervous system as also effects on skeletal and smooth muscle preparations, as other members of Apocynaceae family have been reported to induce varieties of pharmacological effects like depression of the CNS and CVS, vasodilatory, local anaesthetic and others 1 . ...
Drugs bearing indole alkaloids are known to produce important pharmacological effects. Kopsia fruticosa (KF), member of thee Genus Kopsia containing four indole alkaloids possesses central nervous system (CNS) pharmacological effects. This study was conducted to explore the CNS effects of KF in rodents. Materials and Methods: The propylene glycolic solution (KF1) and aqueous solution (KF2) were prepared from the dried extract of the leaves of KF. Evaluation of hexobarbitone induced sleeping time in mice, analgesic effect by Tail flick response on thermal stimulus in rats, locomotor activity by Spontaneous motor activity and rota rod method in rats, sedative ataxic score by inclined plane method in mice and behavioural activity by Gross behavioural effects, Conditional Avoidance response, and cataleptic effects in rats were performed at 2, 4, 8,16 mg/kg of body weight respectively. Results: KF1 reduced the spontaneous locomotor activity and exploratory behaviour in mice (p<0.001-0.01) more than KF2. KF1 in all doses potentiated the hypnotic dose (p<0.001) of hexobarbitone and sub-hypnotic dose (upto 80% potentiation) of hexabarbitone as compared to only 40% potentiation by KF2. Anti-nociception effect was found to be absent at all doses. KF1 possesses moderate sedative ataxic effect (p<0.001) and KF2 at 8mg/kg b.w. revealed mild effect (p<0.05) when compared to pentobarbitone. KF1 induced a moderate degree of catalepsy and potentiated cataleptic and sub-cataleptic doses of haloperidol at all doses (p<0.001). Conclusion: The present study has revealed that the propylene glycolic extract of the leaves Kopsia fruticosa possesses profound action on the CNS thereby paving the way to further research.
... In 1946, Loewe and his team managed to perform an experiment with individual cannabinoids in rabbits in mice, and was the first to note the lack of catalepsy seen with the administration of CBD, an effect that was quite evident with THC (Pertwee, 1972). In the 1960s and 1970s, many studies concerning the pharmacological mechanisms of THC and CBD were conducted in both animal and human studies, with the main focus also being on the effects and mechanisms of THC (Paton and Pertwee, 1972;Pertwee 1972). ...
... In 1946, Loewe and his team managed to perform an experiment with individual cannabinoids in rabbits in mice, and was the first to note the lack of catalepsy seen with the administration of CBD, an effect that was quite evident with THC (Pertwee, 1972). In the 1960s and 1970s, many studies concerning the pharmacological mechanisms of THC and CBD were conducted in both animal and human studies, with the main focus also being on the effects and mechanisms of THC (Paton and Pertwee, 1972;Pertwee 1972). ...
The cannabis plant contains the naturally occurring substance cannabidiol, also known as CBD. As opposed to its more widely known relative, tetrahydrocannabinol (THC), cannabidiol (CBD), does not possess any psychoactive or euphoria-inducing properties, and is widely regarded as harmless and non-addictive. Due to its alleged medicinal advantages, which are thought to include pain relief, anxiety reduction, epilepsy management and anti-inflammatory characteristics, CBD has attracted a lot of attention in recent years, in both human and veterinary medicine. The different kinds of CBD products available include oils, tinctures, capsules, lotions, and even edibles in the form of cookies and candy. In the field of veterinary medicine, the use of CBD has become more and more prevalent in recent years, and a formulation of treats for dogs and cats containing varying quantities of cannabidiol have been put on the market. Despite growing in popularity, CBD's legal status is still a little hazy in many nations, and more study is required to fully comprehend both its advantages and disadvantages. This article aims to review CBD's history, mechanisms of action, potential therapeutic roles as well as adverse effects that have been encountered thus far in clinical studies.
... Catalepsy was assessed in the bar-holding assay 5 min after drug administration. 66,67 The mice were placed such that their forepaws clasped a 0.7 cm ring clamp positioned 4.5 cm above the surface of the testing space. The length of time the ring was gripped by the animal was recorded. ...
... The trial was ended if the mouse turned its head or body or made three consecutive escape attempts. 66,67 Body temperature was measured by rectal thermometer 15 min after drug administration. Antinociceptive effects were assessed in the standard warm-water (52°C) tail-flick test 20 min after drug administration. ...
We apply the magic methyl effect to improve the potency/efficacy of GAT211, the prototypic 2-phenylindole-based cannabinoid type-1 receptor (CB1R) agonist-positive allosteric modulator (ago-PAM). Introducing a methyl group at the α-position of nitro group generated two diastereomers, the greater potency and efficacy of erythro, (±)-9 vs threo, (±)-10 constitutes the first demonstration of diastereoselective CB1R-allosteric modulator interaction. Of the (±)-9 enantiomers, (-)-(S,R)-13 evidenced improved potency over GAT211 as a CB1R ago-PAM, whereas (+)-(R,S)-14 was a CB1R allosteric agonist biased toward G protein- vs β-arrestin1/2-dependent signaling. (-)-(S,R)-13 and (+)-(R,S)-14 were devoid of undesirable side effects (triad test), and (+)-(R,S)-14 reduced intraocular pressure with an unprecedentedly long duration of action in a murine glaucoma model. (-)-(S,R)-13 docked into both a CB1R extracellular PAM and intracellular allosteric-agonist site(s), whereas (+)-(R,S)-14 preferentially engaged only the latter. Exploiting G-protein biased CB1R-allosteric modulation can offer safer therapeutic candidates for glaucoma and, potentially, other diseases.
... Two motor phenotyping tests, the Ring Test and the Open Field Test, were used to measure THC response. The Ring Test was adapted from Pertwee (1972) and used to assess sensitivity to THC. The amount of time spent immobile on a horizontal wire ring was measured over 5 min. ...
... We then measured sensitivity to the motor depressing effects of a 10 mg/kg (i.p.) dose of THC in male B6 and D2 mice using two different assays. The first assay, the ring test, was developed by Roger Pertwee in the 1970s as a test to measure the cataleptic effects of cannabis extracts in mice (Pertwee, 1972). In the ring test, immobility on a horizontal metal ring was used as a measure of THC-induced catalepsy. ...
C57BL/6J (B6) and DBA/2J (D2) inbred mouse strains are highly variable genetically and differ in a large number of behavioral traits related to striatal function, including depression, anxiety, stress response, and response to drugs of abuse. The genetic basis of these phenotypic differences are, however, unknown. Here, we present a comparison of the striatal proteome between B6 and D2 and relate differences at the protein level to strain differences at the mRNA level. We also leverage a recombinant inbred BXD population derived from B6 and D2 strains to investigate the role of genetic variation on the regulation of mRNA and protein levels. Finally, we test the hypothesis that differential protein expression contributes to differential behavioral responses between the B6 and D2 strain. We detected the expression of over 2,500 proteins in membrane-enriched protein fractions from B6 and D2 striatum. Of these, 160 proteins demonstrated significant differential expression between B6 and D2 strains at a 10% false discovery level, including COMT, GABRA2, and cannabinoid receptor 1 (CNR1)-key proteins involved in synaptic transmission and behavioral response. Similar to previous reports, there was little overlap between protein and transcript levels (25%). However, the overlap was greater (51%) for proteins demonstrating genetic regulation of cognate gene expression. We also found that striatal proteins with significantly higher or lower relative expression in B6 and D2 were enriched for dopaminergic and glutamatergic synapses and processes involved in synaptic plasticity [e.g., long-term potentiation (LTP) and long-term depression (LTD)]. Finally, we validated higher expression of CNR1 in B6 striatum and demonstrated greater sensitivity of this strain to the locomotor inhibiting effects of the CNR1 agonist, Δ9-tetrahydrocannabinol (THC). Our study is the first comparison of differences in striatal proteins between the B6 and D2 strains and suggests that alterations in the striatal proteome may underlie strain differences in related behaviors, such as drug response. Furthermore, we propose that genetic variants that impact transcript levels are more likely to also exhibit differential expression at the protein level.
... There are conflicting reports on the activity of 1 at the GPR55 receptor in vitro. This receptor has been claimed, by many authors, to be a third cannabinoid receptor [29][30][31]65]. Using two different assays in the same cell line (HEK293) transfected with human GPR55, 1 weakly activated GPR55 in a β-arrestin assay [66], but potently activated it in a GTPγS binding assay with a submicromolar half maximal response (Table 3) [67]. ...
... At higher doses of 3, 10, 30, and 56 mg kg À1 , 2 acts as an agonist by producing antinociception in an acute model of pain and causes immobility in the ring test (a quantitative test for measuring catalepsy [65]) [72]. In this study, the CB 1 receptor antagonist rimonabant blocked the agonist effect of 2 on antinociception but not on immobility in the ring test. ...
Cannabis sativa has been used for recreational, therapeutic and other uses for thousands of years. The plant contains more than 120 C21 terpenophenolic constituents named phytocannabinoids. The Δ9-tetrahydrocannabinol type class of phytocannabinoids comprises the largest proportion of the phytocannabinoid content. Δ9-tetrahydrocannabinol was first discovered in 1971. This led to the discovery of the endocannabinoid system in mammals, including the cannabinoid receptors CB1 and CB2. Δ9-Tetrahydrocannabinol exerts its well-known psychotropic effects through the CB1 receptor but this effect of Δ9-tetrahydrocannabinol has limited the use of cannabis medicinally, despite the therapeutic benefits of this phytocannabinoid. This has driven research into other targets outside the endocannabinoid system and has also driven research into the other non-psychotropic phytocannabinoids present in cannabis. This chapter presents an overview of the molecular pharmacology of the seven most thoroughly investigated phytocannabinoids, namely Δ9-tetrahydrocannabinol, Δ9-tetrahydrocannabivarin, cannabinol, cannabidiol, cannabidivarin, cannabigerol, and cannabichromene. The targets of these phytocannabinoids are defined both within the endocannabinoid system and beyond. The pharmacological effect of each individual phytocannabinoid is important in the overall therapeutic and recreational effect of cannabis and slight structural differences can elicit diverse and competing physiological effects. The proportion of each phytocannabinoid can be influenced by various factors such as growing conditions and extraction methods. It is therefore important to investigate the pharmacology of these seven phytocannabinoids further, and characterise the large number of other phytocannabinoids in order to better understand their contributions to the therapeutic and recreational effects claimed for the whole cannabis plant and its extracts.
... Isolation and structure elucidation of 2-AG 32,107 Research on cannabinoid pharmacology and metabolism 8,9,15 Discovery of CB1 (REF. 27 Cloning of the first endocannabinoidbiosynthesizing enzyme 119 Discovery and evaluation of endocannabinoid-like brain components 95,96,111 , discovery and evaulation of functions of FAAH and MAGL inhibitors 33,83,112,113 , cell biology 114 and neuroscience studies carried out 115,116 and clinical trials initiated 101,117,118 Nature Reviews | Neuroscience 3,4,104,105 , and pharmacology was mainly done using synthetic com pounds 5 . ...
... 27 Cloning of the first endocannabinoidbiosynthesizing enzyme 119 Discovery and evaluation of endocannabinoid-like brain components 95,96,111 , discovery and evaulation of functions of FAAH and MAGL inhibitors 33,83,112,113 , cell biology 114 and neuroscience studies carried out 115,116 and clinical trials initiated 101,117,118 Nature Reviews | Neuroscience 3,4,104,105 , and pharmacology was mainly done using synthetic com pounds 5 . Following the isolation and structure elucidation of the plant cannabinoids, particularly of cannabidiol 106 and of Δ9-tetrahydrocannabinol (Δ 9 -THC) 6 , pharmacological and physiological work was initiated 8,9,15 . The identification of cannabinoid receptors 24,29,31 , of endogenous cannabinoids 30,32,107 and of receptor antagonists 50,66 made possible extensive pharmacological and neurobiological research leading to cloning of the anandamide-degrading enzyme fatty acid amide hydrolase (FAAH) 108 , the discovery of retrograde signaling by 2-arachidonoy l glycerol (2-AG) 45 , the discovery of allosteric sites on cannabi noid receptor 1 (CB1) 33 , the discovery that endocannabinoids bind to receptors other than CB1 and CB2 , the discovery and evaluation of endocannabinoid-like molecules in the brain 95,96 and the discovery and function of inhibitors of the endocannabinoid-degrading enzymes 112,113 . ...
Isolation and structure elucidation of most of the major cannabinoid constituents - including Δ(9)-tetrahydrocannabinol (Δ(9)-THC), which is the principal psychoactive molecule in Cannabis sativa - was achieved in the 1960s and 1970s. It was followed by the identification of two cannabinoid receptors in the 1980s and the early 1990s and by the identification of the endocannabinoids shortly thereafter. There have since been considerable advances in our understanding of the endocannabinoid system and its function in the brain, which reveal potential therapeutic targets for a wide range of brain disorders.
... LaVigne [22] found that the terpenes α-humulene, geraniol, linalool, and β-pinene produced cannabinoid tetrad behaviors in mice [23][24][25][26], suggesting cannabimimetic activity. Further, some mice behaviors could be blocked by cannabinoid or adenosine receptor antagonists, suggesting a mixed mechanism of action. ...
Terpenes and terpenoids content in cannabis plant was already studied in the past with three used methods. Since these works did not compare the content of these substances under the same conditions, we tried to make this comparison exactly. Three different gas chromatography/mass spectrometry (GS/MS) methods - hexane based liquid extraction (Liq), static head-space extraction (HS), and head-space solid phase microextraction (SPME) – were compared to identify volatile compounds in four different cannabis chemotypes - Green fields, Titan chemotype, Black Domina chemotype, and Neptune chemotype. The main compounds focused on were monoterpenes/monoterpenoids and sesquiterpenes/sesquiterpenoids. Extraction with hexane gave comparable results, however the other two methods allowed for the identification of more substances. For the final evaluation of the comparison of the three methods of analysis, extraction with hexane gives comparable results (which is advantageous for quantitative analysis), although the other two methods allowed for the identification of more substances. This means that the same method should be used everywhere for the quantitative evaluation of constituents in cannabis.
... Catalepsy. Potential induction of catalepsy was assessed using the ring test as described 43 ; 800 μg/mL G418 (CB1-CHO-cAMP); 800 μg/mL G418 and 300 μg/mL hygromycin B (CB1-CHO-βarr2). WT CHO were grown as stated above without selection antibiotic. ...
Limited evidence has suggested that terpenes found in Cannabis sativa are analgesic, and could produce an “entourage effect” whereby they modulate cannabinoids to result in improved outcomes. However this hypothesis is controversial, with limited evidence. We thus investigated Cannabis sativa terpenes alone and with the cannabinoid agonist WIN55,212 using in vitro and in vivo approaches. We found that the terpenes α-humulene, geraniol, linalool, and β-pinene produced cannabinoid tetrad behaviors in mice, suggesting cannabimimetic activity. Some behaviors could be blocked by cannabinoid or adenosine receptor antagonists, suggesting a mixed mechanism of action. These behavioral effects were selectively additive with WIN55,212, suggesting terpenes can boost cannabinoid activity. In vitro experiments showed that all terpenes activated the CB1R, while some activated other targets. Our findings suggest that these Cannabis terpenes are multifunctional cannabimimetic ligands that provide conceptual support for the entourage effect hypothesis and could be used to enhance the therapeutic properties of cannabinoids.
... During the ring test, the mouse was placed on an elevated ring (6.35-cm-diameter wire ring suspended 16 cm above a flat platform) and recorded for 5 min to assess catalepsy (Pertwee, 1972). ...
Background and Purpose
Src homology 3‐domain growth factor receptor‐bound 2‐like endophilin interacting protein 1 (SGIP1) interacts with cannabinoid CB1 receptors. SGIP1 is abundantly and principally expressed within the nervous system. SGIP1 and CB1 receptors co‐localize in axons and presynaptic boutons. SGIP1 interferes with the internalization of activated CB1 receptors in transfected heterologous cells. Consequently, the transient association of CB1 receptors with β‐arrestin2 is enhanced and prolonged, and CB1 receptor‐mediated ERK1/2 signalling is decreased. Because of these actions, SGIP1 may modulate affect, anxiety, pain processing, and other physiological processes controlled by the endocannabinoid system (ECS).
Experimental Approach
Using a battery of behavioural tests, we investigated the consequences of SGIP1 deletion in tasks regulated by the ECS in SGIP1 constitutive knockout (SGIP1−/−) mice.
Key Results
In SGIP1−/− mice, sensorimotor gating, exploratory levels, and working memory are unaltered. SGIP1−/− mice have decreased anxiety‐like behaviours. Fear extinction to tone is facilitated in SGIP1−/− females. Several cannabinoid tetrad behaviours are altered in the absence of SGIP1. SGIP1−/− males exhibit abnormal behaviours on Δ⁹‐tetrahydrocannabinol withdrawal. SGIP1 deletion also reduces acute nociception, and SGIP1−/− mice are more sensitive to analgesics.
Conclusion and Implications
SGIP1 was detected as a novel protein associated with CB1 receptors, and profoundly modified CB1 receptor signalling. Genetic deletion of SGIP1 particularly affected behavioural tests of mood‐related assessment and the cannabinoid tetrad. SGIP1−/− mice exhibit decreased nociception and augmented responses to CB1 receptor agonists and morphine. These in vivo findings suggest that SGIP1 is a novel modulator of CB1 receptor‐mediated behaviour.
... A study was conducted on tardive dyskinesias, which are related to the nigrostriatal pathway, which, itself, is affected by the administration of reserpine (1 mg/kg), a drug which has been shown to reduce glutamate consumption (Burger et al., 2005). Said research obtained favorable results in behavioral evaluations via the administration of CBD (0.5 and 5 mg/kg), finding improved memory and reductions in oral dyskinesia and the cataleptic effect (Peres et al., 2016), which describes the subject's inability to correct an imposed posture (Pertwee, 1972), without modifying locomotor activity and anxiety in the model (Peres et al., 2016). ...
The phytocannabinoids of Cannabis sativa L. have, since ancient times, been proposed as a pharmacological alternative for treating various central nervous system (CNS) disorders. Interestingly, cannabinoid receptors (CBRs) are highly expressed in the basal ganglia (BG) circuit of both animals and humans. The BG are subcortical structures that regulate the initiation, execution, and orientation of movement. CBRs regulate dopaminergic transmission in the nigro-striatal pathway and, thus, the BG circuit also. The functioning of the BG is affected in pathologies related to movement disorders, especially those occurring in Parkinson’s disease (PD), which produces motor and non-motor symptoms that involving GABAergic, glutamatergic, and dopaminergic neural networks. To date, the most effective medication for PD is levodopa (l-DOPA); however, long-term levodopa treatment causes a type of long-term dyskinesias, l-DOPA-induced dyskinesias (LIDs). With neuromodulation offering a novel treatment strategy for PD patients, research has focused on the endocannabinoid system (ECS), as it participates in the physiological neuromodulation of the BG in order to control movement. CBRs have been shown to inhibit neurotransmitter release, while endocannabinoids (eCBs) play a key role in the synaptic regulation of the BG. In the past decade, cannabidiol (CBD), a non-psychotropic phytocannabinoid, has been shown to have compensatory effects both on the ECS and as a neuromodulator and neuroprotector in models such as 6-hydroxydopamine (6-OHDA), 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP), and reserpine, as well as other PD models. Although the CBD-induced neuroprotection observed in animal models of PD has been attributed to the activation of the CB1 receptor, recent research conducted at a molecular level has proposed that CBD is capable of activating other receptors, such as CB2 and the TRPV-1 receptor, both of which are expressed in the dopaminergic neurons of the nigro-striatal pathway. These findings open new lines of scientific inquiry into the effects of CBD at the level of neural communication. Cannabidiol activates the PPARγ, GPR55, GPR3, GPR6, GPR12, and GPR18 receptors, causing a variety of biochemical, molecular, and behavioral effects due to the broad range of receptors it activates in the CNS. Given the low number of pharmacological treatment alternatives for PD currently available, the search for molecules with the therapeutic potential to improve neuronal communication is crucial. Therefore, the investigation of CBD and the mechanisms involved in its function is required in order to ascertain whether receptor activation could be a treatment alternative for both PD and LID.
... Some of the effects produced by Δ 9 -THC in these early animal studies were severe motor disturbances, redness of the mucous membrane that covers the eyeball, slow movements, decline of aggression, sleepy state, and decreased spontaneous locomotion. Subsequently, Roger Pertwee (1972) tested Δ 9 -THC in the ring test, a quantitative in vivo assay for catalepsy (muscular rigidity and fixed posture), and concluded that indeed Δ 9 -THC was producing catalepsy. Billy Martin's group (Martin et al. 1991) then incorporated the ring test and three other bioassays into the mouse tetrad assay, including catalepsy, hypokinesia (inactivity), hypothermia (reduced body temperature), and antinociception (pain relief). ...
The Cannabis sativa plant has been used medicinally and recreationally for thousands of years, but recently only relatively some of its constituents have been identified. There are more than 550 chemical compounds in cannabis, with more than 100 phytocannabinoids being identified, including Δ⁹-tetrahydrocannabinol (THC) and cannabidiol (CBD). These phytocannabinoids work by binding to the cannabinoid receptors, as well as other receptor systems. Also within cannabis are the aromatic terpenes, more than 100 of which have been identified. Cannabis and its constituents have been indicated as therapeutic compounds in numerous medical conditions, such as pain, anxiety, epilepsy, nausea and vomiting, and post-traumatic stress disorder. This chapter provides an overview of some of the biological effects of a number of the cannabinoids and terpenes, as well as discussing their known mechanisms of action and evidence of potential therapeutic effects.
... Potential induction of catalepsy was assessed using the ring test as described [42]. Mice were baselined, injected with compound, and then assessed with the ring test at 15 . ...
Limited evidence has suggested that terpenes found in Cannabis sativa are analgesic, and could produce an “entourage effect” whereby they modulate cannabinoids to result in improved outcomes. However this hypothesis is controversial, with limited evidence. We thus investigated Cannabis sativa terpenes alone and with the cannabinoid agonist WIN55,212 using in vitro and in vivo approaches. We found that the terpenes α-humulene, geraniol, linalool, and β-pinene produced cannabinoid tetrad behaviors in mice, suggesting cannabimimetic activity. Some behaviors could be blocked by cannabinoid or adenosine receptor antagonists, suggesting a mixed mechanism of action. These behavioral effects were additive with WIN55,212, providing support for a terpene “entourage effect.” In vitro experiments showed that all terpenes activated the CB1R, while some activated other targets. Our findings suggest that these Cannabis terpenes are multifunctional cannabimimetic ligands that provide support for the entourage effect hypothesis and could be used to enhance the therapeutic properties of cannabinoids.
... However, the precise mechanism of the efficacy of CBD signaling is not fully understood yet. Similarly, CB1 antagonist effects of Δ 9 -THCV were observed, while high concentration appeared to be agonistic in a model of antinociception [93,96]. Other data showed that Δ 9 -THCV exerts antiepileptic and anticonvulsant activities, suggesting a CB1mediated effect [97]. ...
Epilepsy contributes to approximately 1% of the global disease burden. By affecting especially young children as well as older persons of all social and racial variety, epilepsy is a present disorder worldwide. Currently, only 65% of epileptic patients can be successfully treated with antiepileptic drugs. For this reason, alternative medicine receives more attention. Cannabis has been cultivated for over 6000 years to treat pain and insomnia and used since the 19th century to suppress epileptic seizures. The two best described phytocannabinoids, (−)-trans-Δ 9-tetrahydrocannabinol (THC) and cannabidiol (CBD) are claimed to have positive effects on different neurological as well as neurodegenerative diseases, including epilepsy. There are different cannabinoids which act through different types of receptors and channels, including the cannabinoid receptor 1 and 2 (CB1, CB2), G protein-coupled receptor 55 (GPR55) and 18 (GPR18), opioid receptor µ and δ, transient receptor potential vanilloid type 1 (TRPV1) and 2 (TRPV2), type A γ-aminobutyric acid receptor (GABAAR) and voltage-gated sodium channels (VGSC). The mechanisms and importance of the interaction between phytocannabinoids and their different sites of action regarding epileptic seizures and their clinical value are described in this review.
... Intraplantar injection of JZL184 in the paw alleviated paclitaxel-induced mechanical allodynia in the injected paw without affecting the uninjected paw, similar to what has been reported in mice with cisplatininduced mechanical hyperalgesia [11]. Systemic administration of CB receptor agonists and MAGL inhibitors such as JZL184 has been reported to produce cannabimimetic side effects such as hypo-motility, catalepsy, motor impairment, tolerance, hypothermia and sedation [40,[50][51][52][53][54]. A recent study showed that a peripherally-restricted cannabinoid receptor agonist could alleviate mechanical and cold allodynia with limited cannabimimetic side effects [55]. ...
Background
Modulation of the endocannabinoid system has been shown to alleviate neuropathic pain. The aim of this study was to evaluate if treatment with paclitaxel, a chemotherapeutic agent that induces neuropathic pain, affects endocannabinoid levels at a time when mice develop paclitaxel-induced mechanical allodynia. We also evaluated the peripheral antiallodynic activity of the endocannabinoid 2-arachidonoyl glycerol (2-AG) and an inhibitor of monoacylglycerol lipase (MAGL), an enzyme responsible for 2-AG hydrolysis.
Methods
Female BALB/c mice were treated intraperitoneally with paclitaxel to induce mechanical allodynia. Levels of the endocannabinoids, N-arachidonoylethanolamine (anandamide, AEA), 2-AG, and the N-acylethanolamines (NAEs), N-palmitoylethanolamide (PEA) and N-oleoylethanolamide (OEA), which are structurally-related to AEA, in the brain, spinal cord and paw skin were measured using LC–MS/MS. Protein expression of MAGL in the paw skin was measured using Wes™. The effects of subcutaneous (s.c.) injection of 2-AG and JZL184 (a MAGL inhibitor) into the right hind paw of mice with paclitaxel-induced mechanical allodynia were assessed using the dynamic plantar aesthesiometer. The effects of pretreatment, s.c., into the right hind paw, with cannabinoid type 1 (CB1) receptor antagonist AM251 and CB2 receptor antagonist AM630 on the antiallodynic effects of 2-AG were also evaluated.
Results
The levels of 2-AG were reduced only in the paw skin of paclitaxel-treated mice, whilst the levels of AEA, PEA and OEA were not significantly altered. There was no change in the expression of MAGL in the paw skin. Administration of 2-AG and JZL184 produced antiallodynic effects against paclitaxel-induced mechanical allodynia in the injected right paw, but did not affect the uninjected left paw. The antiallodynic activity of 2-AG was antagonized by both AM251 and AM630.
Conclusion
These results indicate that during paclitaxel-induced mechanical allodynia there is a deficiency of 2-AG in the periphery, but not in the CNS. Increasing 2-AG in the paw by local administration of 2-AG or a MAGL inhibitor, alleviates mechanical allodynia in a CB1 and CB2 receptor-dependent manner.
... One proceeded to sing, declare himself fit and call for more food before falling asleep. When then examined, he was insensitive to pain and his limbs remained waxen and doll-like in any position placed-the first demonstration of catalepsy due to cannabis, the latter phenomenon now recognized as a key part of the cannabinoid tetrad (along with hypomotility, analgesia, and hypothermia) (Pertwee 1972;Fride and Sañudo-Peña 2002). One other patient also slept, while the third was alert, seemingly well and symptom-free. ...
Cannabis or hemp has been employed medicinally in Ireland since at least the Anglo-Saxon era, more than 1000 years ago. Its use came to the fore, however when William B. O’Shaughnessy, an Irish physician in India, became familiar with the versatility of Indian hemp in the treatment of rheumatic diseases, tetanus, cholera and epilepsy in 1838. His knowledge, acquired through application of the scientific method combining ethnobotanical teachings, animal experimentation and clinical observations in humans, was quickly shared with colleagues in Ireland and England. This led in turn to rapid advances in therapeutics by Michael Donovan in neuropathic pain states, Dominic Corrigan in chorea and trigeminal neuralgia, Fleetwood Churchill in uterine hemorrhage, and Richard Greene in the use of cannabis as a prophylactic treatment of migraine. In each instance the observations of these past treatments are examined in light of 21st century advances in pathophysiology so that their rationale and scientific basis are clarified. The venerable Irish tradition of cannabis research is being carried on contemporaneously by numerous prominent scientists with the promise of important advancements yet to come.
... 169 Interestingly, this effect has not been found with CBD studies in animal models. [170][171][172] As well, other measures including blood pressure, heart rate, glucose levels, and pH have also all been found to be unaffected by CBD. 167,173 In human studies, CBD has demonstrated a good safety profile with both short term and chronic use, such that common adverse effects typically associated with antipsychotics are not reported [174][175][176] ; as well, no changes in physiological functions (heart rate, body temperature, blood pressure), 169 or verbal memory have been found with CBD. ...
Prevalence of psychiatric disorders continues to rise globally, yet remission rates and patient outcome remain less than ideal. As a result, novel treatment approaches for these disorders are necessary to decrease societal economic burden, as well as increase individual functioning. The recent discovery of the endocannabinoid system has provided an outlet for further research into its role in psychiatric disorders, because efficacy of targeted treatments have been demonstrated in medical illnesses, including cancers, neuropathic pain, and multiple sclerosis. The present review will investigate the role of the endocannabinoid system in psychiatric disorders, specifically schizophrenia, depressive, anxiety, and posttraumatic stress disorders, as well as attention-deficit hyperactivity disorder. Controversy remains in prescribing medicinal cannabinoid treatments due to the fear of adverse effects. However, one must consider all potential limitations when determining the safety and tolerability of cannabinoid products, specifically cannabinoid content (ie, Δ⁹-tetrahydrocannabinol vs cannabidiol) as well as study design. The potential efficacy of cannabinoid treatments in the psychiatric population is an emerging topic of interest that provides potential value going forward in medicine.
... Cannabinoid receptor agonists produce immobility and catalepsy (Pertwee, 1972;Moss et al., 1981;Compton et al., 1993). However, the cannabinoidrelated catalepsy appears to be accompanied by a hypersensitivity to external stimuli that can disrupt the cataleptic behavior (Kawasaki et al., 1980). ...
The inferior colliculus (IC), a midbrain structure that processes acoustic information of aversive nature, is distinguished from other auditory nuclei in the brainstem by its connections with structures of the motor system. Previous evidence relating the IC to motor behavior shows that glutamatergic and GABAergic-mediated mechanisms in the IC exert influence on systemic haloperidol-induced catalepsy. There is substantial evidence supporting a role played by the endocannabinoid system as a modulator of the glutamatergic neurotransmission, as well as the dopaminergic activity in the basal nuclei and therefore it may be considered as a potential pharmacological target for the treatment of movement disorders. The present study evaluated if the endocannabinoid system in the IC plays a role in the elaboration of systemic haloperidol-induced catalepsy. Male Wistar rats received intracollicular microinjection of either the endogenous cannabinoid anandamide (AEA) at different concentrations (5, 50 or 100pmol/0.2μl), the CB1 cannabinoid receptor antagonist AM251 at 50, 100 or 200pmol/0.2μl or vehicle, followed by intraperitoneal (IP) administration of either haloperidol at 0.5 or 1mg/kg or physiological saline. Systemic injection of haloperidol at both doses (0.5 or 1mg/kg, IP) produced a cataleptic state, compared to vehicle/physiological saline-treated group, lasting 30 and 50 minutes after systemic administration of dopaminergic receptors non-selective antagonist. The microinjection of AEA at 50pmol/0.2μl increased the latency for stepping down from the horizontal bar after systemic administration of haloperidol. Moreover, the intracollicular administration of AEA at 50pmol/0.2μl was able to increase the duration of catalepsy as compared to AEA at 100pmol/0.2μl-treated group. Intracollicular pretreatment with AM251 at the intermediate concentration (100pmol/0.2μl) was able to decrease the duration of catalepsy after systemic administration of haloperidol. However, neither the intracollicular microinjection of AM251 at the lowest (50 pmol/0.2μl) nor at the highest (200 pmol/0.2μl) concentration was able to block the systemic haloperidol-induced catalepsy. Furthermore, the intracollicular administration of AM251 at 100pmol/0.2μl was able to decrease the duration of catalepsy as compared to AM251 at 50pmol/0.2μl-and AM251 at 200pmol/0.2μl-treated group. The latency for stepping down from the horizontal bar - induced by haloperidol administration- was decreased when microinjection of AEA at 50pmol/0.2μl was preceded with blockade of CB1 receptor with AM251 (100pmol/0.2μl). Our results strengthen the involvement of CB1-signalled endocannabinoid mechanisms of the IC in the neuromodulation of catalepsy induced by systemic administration of dopaminergic receptors non-selective antagonist haloperidol.
... Vertical rearing was assessed as the number of rears in an open field. Ring test immobility (catalepsy) was then assessed as time spent motionless on a 5.5-cm diameter ring, for up to 4 min (Pertwee, 1972). Rectal body temperature was measured immediately before food administration and again after the ring test. ...
... The time during which the mouse remained immobile after placement on a metal ring of 5.5 cm diameter fixed approximately 16 cm above a table top, was recorded for 4 min [57]. This immobility time was developed by Pertwee and was taken as an index of catalepsy [58]. ...
... The cannabimimetic effects of cannabis and THC, which in rodents are assessed using "tetrad" tests (catalepsy, hypomotility, analgesia and hypothermia), are due to central CB 1 receptor stimulation (Pertwee, 1972;Howlett et al., 2002;Varvel et al., 2005). In contrast, CB 2 R is expressed chiefly by leucocytes, which suggest that cannabinoids may control immune function (Howlett et al., 2002;Klein, 2005;van Sickle et al., 2005). ...
... Ring Test. Catalepsy was assessed using the ring test as previously described (Pertwee, 1972). Immobility latency (in seconds) that the animal spent motionless on the ring during a 5-minute observation period was recorded. ...
Cannabinoids suppress neuropathic pain through activation of cannabinoid CB1 and/or CB2 receptors. However, unwanted CB1-mediated cannabimimetic effects limit clinical use. We asked whether CP55,940, a potent cannabinoid that binds with similar affinity to CB1 and CB2 in vitro, produces functionally separable CB1- and CB2-mediated pharmacological effects in vivo. We evaluated anti-allodynic effects, possible tolerance, and cannabimimetic effects (i.e., hypothermia, catalepsy, and CB1-dependent withdrawal signs) following systemic CP55,940 treatment in a mouse model of toxic neuropathy produced by a chemotherapeutic agent paclitaxel. The contribution of CB1 and CB2 receptors to in vivo actions of CP55,940 was evaluated using CB1 knockout (CB1KO), CB2 knockout (CB2KO), and wildtype (WT) mice. Low dose CP55,940 (0.3 mg/kg/day i.p.) suppressed paclitaxel-induced allodynia in WT and CB2KO, but not CB1KO mice. Low dose CP55,940 also produced hypothermia and rimonabant-precipitated withdrawal in WT, but not CB1KO mice. In WT mice, tolerance developed to CB1-mediated hypothermic effects of CP55,940 earlier than to anti-allodynic effects. High dose CP55,940 (10 mg/kg/day i.p.) produced catalepsy in WT mice, which precluded determination of anti-allodynic efficacy, but produced sustained CB2-mediated suppression of paclitaxel-induced allodynia in CB1KO mice; these anti-allodynic effects were blocked by the CB2 antagonist AM630. High dose CP55,940 did not produce hypothermia or rimonabant-precipitated withdrawal in CB1KO mice. Our results using the mixed CB1/CB2 agonist CP55,940 document that CB1 and CB2 receptor activations produce mechanistically distinct suppression of neuropathic pain. Our study highlights the therapeutic potential of targeting cannabinoid CB2 receptors to bypass unwanted central effects associated with CB1 receptor activation.
The American Society for Pharmacology and Experimental Therapeutics.
... These observations contradict other studies that reported a cataleptogenic response in rodents following the single administration of cannabis extracts or their psychoactive constituent ∆ 9 -THC. In rats, catalepsy has been reported following intravenous (12.5 mg/kg), intraperitoneal or subcutaneous (100 mg/kg) administrations of cannabis extract (Pertwee, 1972) as well as marijuana (200 mg) smoke inhalation (Varvel et al., 2005). Rats or mice administered ∆ 9 -THC intravenously (Kataoka et al., 1987;Kinoshita et al., 1994) or intraperito-neally (5-20 mg/kg) (Pertwee and Greentree, 1998) also exhibited cataleptogenic response. ...
Haloperidol is a classic antipsychotic drug known for its propensity to cause extrapyramidal symptoms due to blockade of dopamine D2 receptors in the striatum. Interest in medicinal uses of cannabis is growing. Cannabis sativa has been suggested as a possible adjunctive in treatment of Parkinson's disease. The present study aimed to investigate the effect of repeated administration of an extract of Cannabis sativa on catalepsy and brain oxidative stress in-duced by haloperidol administration in mice. Cannabis extract was given by subcutaneous route at 5, 10 or 20 mg/kg (expressed as ∆ 9 -tetrahydrocannabinol) once daily for 18 days and the effect on haloperidol (1 mg/kg, i.p.)-induced catalepsy was examined at selected time in-tervals using the bar test. Mice were euthanized 18 days after starting cannabis injection when biochemical assays were carried out. Malondialdehyde (MDA), reduced glutathione (GSH) and nitric oxide (the concentrations of nitrite/nitrate) were determined in brain and liver. In saline-treated mice, no catalepsy was observed at doses of cannabis up to 20 mg/kg. Mice treated with haloperidol at the dose of 1 mg/kg, exhibited significant cataleptic response. Mice treated with cannabis and haloperidol showed significant decrease in catalepsy duration, compared with the haloperidol only treated group. This decrease in catalepsy duration was evident on days 1-12 after starting cannabis injection. Later the effect of cannabis was not ap-parent. The administration of only cannabis (10 or 20 mg/kg) decreased brain MDA by 17.5 and 21.8 %, respectively. The level of nitric oxide decreased by 18 % after cannabis at 20 mg/kg. Glucose in brain decreased by 20.1 % after 20 mg/kg of cannabis extract. The ad-ministration of only haloperidol increased MDA (22.2 %), decreased GSH (25.7 %) and in-creased brain nitric oxide by 44.1 %. The administration of cannabis (10 or 20 mg/kg) to haloperidol-treated mice resulted in a significant decrease in brain MDA and nitric oxide as well as a significant increase in GSH and glucose compared with the haloperidol-control group. Cannabis had no significant effects on liver MDA, GSH, nitric oxide in saline or haloperidol-treated mice. It is concluded that cannabis improves catalepsy induced by haloperidol though the effect is not maintained on repeated cannabis administration. Cannabis alters the oxidative status of the brain in favor of reducing lipid peroxidation, but reduces brain glucose, which would impair brain energetics.
... Catalepsy was measured using a modified "ring test" as originally described by Pertwee. 23 The mice were placed on a rubber-coated metal ring (6 cm in diameter) fixed horizontally at a height of 30 cm. CB 1 cannabinoid agonists cause animals to become cataleptic, and the sum of all times during which the mice were immobile was registered for a 5-minute period and compared with the time registered in control animals. ...
Based on numerous pharmacological studies that have revealed an interaction between cannabinoid and opioid systems at the molecular, neurochemical, and behavioral levels, a new series of hybrid molecules has been prepared by coupling the molecular features of two wellknown drugs, ie, rimonabant and fentanyl. The new compounds have been tested for their affinity and functionality regarding CB1 and CB2 cannabinoid and μ opioid receptors. In [³⁵S]-GTPγS (guanosine 5′-O-[gamma-thio]triphosphate) binding assays from the post-mortem human frontal cortex, they proved to be CB1 cannabinoid antagonists and μ opioid antagonists. Interestingly, in vivo, the new compounds exhibited a significant dual antagonist action on the endocannabinoid and opioid systems.
... The test was repeated at 90 min and 120 min interval after treatment of extract. Immobility was expressed as an 'immobility index', defined as that percentage of the total time spent on the ring during which the animal remains motionless (Pertwee 1972). ...
Andrographis paniculata (Burm. F.) Wall. Ex Nees (Acanthaceae) also called as Kalmegh, or “King of Bitters”. In Ayurveda, Andrographis paniculata is classified as a Rasayana herb. More than 50 % of the poly-herbal formulations commercialized in India for treatment of liver function disorders contain Andrographis paniculata. Pilot study and general neuropharmacological screening were conducted with analytically standardized Andrographis paniculata extract (AP), to evaluate its
therapeutic potential for mental health problems. A battery of rodent behavioral models developed in our laboratory was used for characterizing brain function modulating activities. Daily oral administrations of even very high doses (800 mg/kg) of the extract were well tolerated by laboratory rodentswithout any apparent behavioral alterations. A single oral dose of the extract (AP 25 to 800 mg/kg) was inactive in mice stress-induced hyperthermia, and apomorphine induced cage-climbing tests in rats. However, dose and duration of treatment dependent efficacy of the extract after its daily doses up to 200 mg/kg/day for 10 days was observed in both the tests. Moreover, dose dependent
effects of the extract in suppressing locomotion, potentiating pentobarbital sleep, and antagonizing pentylenetetrazole or maximal electroshock triggered seizureswere also apparent after
its 10 daily doses up to 200 mg/kg/day. Anxiolytics and antidepressants-like activity of AP treatment was also apparent in rats after 10 daily doses. Therefore, prolonged daily oral intake of Andrographis paniculata extract gradually suppresses central sensitivity to acute stressful stimuli, and eventually down regulates central dopaminergic receptors. Benzodiazepines like anxiolytic and seizure suppressing activities of the extract can be expected after its daily intake.
... Along with these bioassays, Loewe (1946) also noted that muscle rigidity (catalepsy), particularly in mice, appeared as a characteristic phenomenon after administration of higher doses of THC. This immobility reaction was reintroduced in the early 1970's as the "ring-test" (Pertwee, 1972). Other early bioassay/in vivo measures, including analgesia, have been summarized by do Valle (do Valle, 1969). ...
... Catalepsy was measured using a modi®ed`ring test' as originally described by Pertwee (1972). Rats were hung by their front paws from a rubber coated metal ring (12 cm diameter) ®xed horizontally at a height allowing their hindpaws to just touch the bench, and the time taken for the rat to move off the ring was measured with a cut-off of 30 s. Latencies were measured immediately prior to and up to 6 h following drug or vehicle administration. ...
We have examined the effects of cannabinoid agonists on hyperalgesia in a model of neuropathic pain in the rat and investigated the possible sites of action. The antihyperalgesic activity of the cannabinoids was compared with their ability to elicit behavioural effects characteristic of central cannabinoid activity. WIN55,212-2 (0.3–10 mg kg−1), CP-55,940 (0.03–1 mg kg−1) and HU-210 (0.001–0.03 mg kg−1) were all active in a ‘tetrad’ of tests consisting of tail-flick, catalepsy, rotarod and hypothermia following subcutaneous administration, with a rank order of potency in each of HU-210>CP-55,940>WIN55,212-2. The effects of WIN55,212-2 in each assay were blocked by the Cannabinoid1 (CB1) antagonist SR141716A. In the partial sciatic ligation model of neuropathic pain WIN55,212-2, CP-55,940 and HU-210 produced complete reversal of mechanical hyperalgesia within 3 h of subcutaneous administration with D50 values of 0.52, 0.08 and 0.005 mg kg−1, respectively. In this model WIN55,212-2 was also effective against thermal hyperalgesia and mechanical allodynia. WIN55,212-2 produced pronounced reversal of mechanical hyperalgesia following intrathecal administration that was blocked by the CB1 antagonist SR141716A. Following intraplantar administration into the ipsilateral hindpaw, WIN55,212-2 produced up to 70% reversal of mechanical hyperalgesia, although activity was also observed at high doses following injection into the contralateral paw. The antihyperalgesic effect of WIN55,212-2 injected into the ipsilateral paw was blocked by subcutaneously administered SR141716A, but was not affected by intrathecally administered SR141716A. These data show that cannabinoids are highly potent and efficacious antihyperalgesic agents in a model of neuropathic pain. This activity is likely to be mediated via an action in both the CNS and in the periphery.
This review paper highlights about the story of the discovery of psychoactive constituent, Δ9-Tetrahydrocannabinol (THC) isolated from the Cannabis sativa (Marijuana or Drug type). Medical Cannabis sativa is also commonly known as Indian hemp, marijuana, Bhang, Ganja, and Charas, which are banned in India as an illicit drug. Sales and cultivation of Medical cannabis (marijuana type) are still illegal in India. According to Ayuverda in India, the narcotic effects of Cannabis plants was well documented more than 3,000 years ago. This was the first Indian evidence to support the medicinal value of Cannabis plants. Cannabis sativa is widely found as a weed in the Himalayan mountain regions of India, China, Nepal, Bhutan, Pakistan and Afghanistan. However, the chemistry of biomolecules responsible for narcotic activity of Cannabis was unknown. This has created a wide interest of many scientists to study cannabis and its compounds. The official discovery of Cannabidiol (CBD) in 1963 and Δ9-tetrahydrocannabinol (THC) in 1964 isolated from cannabis sativa at Israel's Weizmann Institute of Science is commonly attributed to Dr. Raphael Mechoulam, known as the Godfather of Cannabis science. Professor Raphael Mechoulam was active in Cannabinoids research work at the Hebrew University of Jerusalem in Israel. He died at the age of 92 on 9th March 2023, and his outstanding contribution in the field of Cannabis research work is very much appreciated. Finally, the contribution of Dr. Roger Adams and the Nobel laureate Dr. Alexander Robertus Todd, Robert Sidney Cahn and Frantisek Santavy and Roger G. Pertwee towards the Cannabinoids research work were also deserved mentioning. Finally, the Cannabis medicines, Sativex (Nabiximols), Epidiolex and Dronabinol are available in the market and used by Doctors prescriptions. This review paper is written in the Memory of
Professor Raphael Mechoulam and Dedicated as a token of respect for his outstanding contribution in the field of Cannabis Science Research
Cannabis is the most widely used illicit drug in the United States, with 14.6 million current users. Cannabis-dependent individuals presenting for treatment typically report cannabis craving; however, the phenomenon has received little research attention. In the absence of a valid, multidimensional questionnaire to assess cannabis craving, we developed the Marijuana Craving Questionnaire (MCQ). The MCQ consists of four constructs or factors that characterize cannabis craving: compulsivity, emotionality, expectancy, and purposefulness. A separate score is calculated for each factor. The MCQ can be used to measure cue-elicited craving in a research setting or natural craving in cannabis-dependent individuals presenting for treatment. Either the 47-item or 12-item version can be used, and standardized instructions for completion of the MCQ should be given. The MCQ can be administered using a paper and pencil form or a computerized version. In a research setting, the MCQ should be administered immediately after cue presentation and repeated frequently to capture the full time course. In a treatment setting, the MCQ should be administered at intake and during and at the end of treatment.
Rationale
The behavioral effects of cannabidiol (CBD) are understudied, but are important, given its therapeutic potential and widespread use as a natural supplement.
Objective
The objective of this study was to test whether a single injection of CBD affected anxiety-like or attention-like behavior, or memory in wildtype mice or mice with reported trait anxiety due to a targeted-gene deletion in a voltage-dependent potassium channel, Kv1.3.
Methods
Wildtype C57BL/6 J and Kv1.3−/− mice of both sexes were reared to adulthood and then administered an intraperitoneal injection of 10 or 20 mg/kg CBD. Mice were behaviorally-phenotyped using the marble-burying test, the light-dark box (LDB), short (1 h) and long-term (24 h) object memory test, the elevated-plus maze (EPM), and the object-based attention task in order to assess obsessive compulsive-, anxiety-, attention-like behaviors, and memory.
Results
We discovered that acute CBD treatment reduced marble burying in male, but not female mice. CBD was effective in lessening anxiety-like behaviors determined by the LDB test in both male and female wildtype mice, whereby the effective dose required to observe the effect in females was less. In Kv1.3−/− mice, CBD increased anxiety-like behaviors in the LDB in both sexes at the higher concentration of CBD and it similarly increased anxiety-like behavior in females in the EPM at the lower concentration of CBD. Long-term object memory was reduced in male wildtype mice at the lower concentration of CBD. Finally, ADHD- or attention-like behaviors were not altered by CBD in wildtype mice, but in Kv1.3−/− mice, females were observed to have a loss in attention while males demonstrated improved attention.
Conclusions
We conclude that administration of a single dose of CBD has immediate effects on mouse behavior that is dose, sex, and anxiety-state dependent – and that these behavioral outcomes are important to examine in parallel human trials.
Many malignant cancers, including breast cancer, have a propensity to invade bones, leading to excruciating bone pain. Opioids are the primary analgesics used to alleviate this cancer-induced bone pain (CIBP) but are associated with numerous severe side effects, including enhanced bone degradation, which significantly impairs patients' quality of life. In contrast, agonists activating only peripheral CB1 receptors (CB1Rs) have been shown to effectively alleviate multiple chronic pain conditions with limited side effects, yet no studies have evaluated their role(s) in CIBP. Here, we demonstrate for the first time that a peripherally selective CB1R agonist can effectively suppress CIBP. Our studies using a syngeneic murine model of CIBP show that both acute and sustained administration of a peripherally restricted CB1R agonist, 4-{2-[-(1E)-1[(4-propylnaphthalen-1-yl)methylidene]-1H-inden-3-yl]ethyl}morpholine (PrNMI), significantly alleviated spontaneous pain behaviors in the animals. This analgesic effect by PrNMI can be reversed by a systemic administration but not spinal injection of SR141716, a selective CB1R antagonist. Additionally, the cancer-induced bone loss in the animals was not exacerbated by a repeated administration of PrNMI. Furthermore, catalepsy and hypothermia, the common side effects induced by cannabinoids, were measured at the supra-therapeutic doses of PrNMI tested. PrNMI induced mild sedation, yet no anxiety nor a decrease in limb movements were detected. Overall, our studies demonstrate that CIBP can be effectively managed by using a peripherally restricted CB1R agonist, PrNMI, without inducing dose-limiting central side effects. Thus, targeting peripheral CB1Rs could be an alternative therapeutic strategy for the treatment of CIBP.
Background
Activation of cannabinoid CB1 receptors suppresses pathological pain but also produces unwanted central side effects. We hypothesized that a positive allosteric modulator (PAM) of CB1 signaling would suppress inflammatory and neuropathic pain without producing cannabimimetic effects or physical dependence. We also asked whether a CB1-PAM would synergize with inhibitors of endocannabinoid deactivation and/or an orthosteric cannabinoid agonist.
Methods
GAT211, a novel CB1-PAM, was evaluated for antinociceptive efficacy and tolerance in models of neuropathic and/or inflammatory pain. Cardinal signs of direct CB1-receptor activation were evaluated together with propensity to induce reward/aversion and physical dependence. Comparisons were made with inhibitors of endocannabinoid deactivation (JZL184, URB597) or an orthosteric cannabinoid agonist (WIN55,212-2). All studies used 5-11 subjects per group.
Results
GAT211 suppressed allodynia induced by complete Freund’s adjuvant (CFA) and the chemotherapeutic agent paclitaxel in wildtype but not CB1 knockout mice. GAT211 did not impede paclitaxel-induced tumor cell line toxicity. GAT211 did not produce cardinal signs of direct CB1-receptor activation in the presence or absence of pathological pain. GAT211 produced synergistic anti-allodynic effects with fatty-acid amide hydrolase (FAAH) and monoacylglycerol lipase (MGL) inhibitors in paclitaxel-treated mice. Therapeutic efficacy was preserved over 19 days of chronic dosing with GAT211 but not the MGL inhibitor JZL184. The CB1 antagonist rimonabant precipitated withdrawal in mice treated chronically with WIN55,212-2 but not GAT211. GAT211 did not induce condition place preference or aversion.
Conclusions
Positive allosteric modulation of CB1 receptor signaling shows promise as a safe and effective analgesic strategy that lacks tolerance, dependence and abuse liability.
GW405833, widely accepted as a cannabinoid CB2 agonist, suppresses pathological pain in preclinical models without unwanted central side effects of CB1 agonists. However, recent in vitro studies suggest that GW405833 may also behave as a non-competitive CB1 antagonist, suggesting that its pharmacology is more complex than initially appreciated. Here, we further investigated the pharmacological specificity of in vivo antinociceptive actions of GW405833 in models of neuropathic (i.e. partial sciatic nerve ligation (PSNL) model) and inflammatory (i.e. complete Freund's adjuvant (CFA) model) pain using CB2 and CB1 knockout (KO) mice, their respective wild-type (WT) mice and both CB2 and CB1 antagonists. GW405833 (3, 10, and 30 mg/kg i.p.) dose-dependently reversed established mechanical allodynia in both pain models in WT mice. However, the anti-allodynic effects of GW405833 were fully preserved in CB2KO mice and absent in CB1KO mice. Furthermore, anti-allodynic efficacy of GW405833 (30 mg/kg i.p.) was completely blocked by the CB1 antagonist SR141716A (10 mg/kg i.p.) but not by the CB2 antagonist SR144528 (10 mg/kg i.p.). Thus, the antinociceptive properties of GW405833 are dependent upon CB1 receptors. GW405833 (30 mg/kg i.p.) was also inactive in a tetrad of tests measuring cardinal signs of CB1 activation. Additionally, unlike SR141716A (10 mg/kg i.p.), GW405833 (10 mg/kg, i.p.) did not act as a CB1 antagonist in vivo to precipitate withdrawal in mice treated chronically with Δ(9)-tetrahydrocannabinol. The present results suggest that anti-allodynic efficacy of GW405833 is CB1-dependent but does not seem to involve engagement of the CB1 receptor's orthosteric site. .
Cannabis is the most widely used illicit drug in the United States, with 14.6 million current users. Cannabis-dependent individuals presenting for treatment typically report cannabis craving; however, the phenomenon has received little research attention. In the absence of a valid, multidimensional questionnaire to assess cannabis craving, we developed the Marijuana Craving Questionnaire (MCQ). The MCQ consists of four constructs or factors that characterize cannabis craving: compulsivity, emotionality, expectancy, and purposefulness. A separate score is calculated for each factor. The MCQ can be used to measure cue-elicited craving in a research setting or natural craving in cannabis-dependent individuals presenting for treatment. Either the 47-item or 12-item version can be used, and standardized instructions for completion of the MCQ should be given. The MCQ can be administered using a paper and pencil form or a computerized version. In a research setting, the MCQ should be administered immediately after cue presentation and repeated frequently to capture the full time course. In a treatment setting, the MCQ should be administered at intake and during and at the end of treatment.
In the absence of any specific behavioral assay for cannabinoids or endocannabinoids, a cannabinoid-induced profile in a series of four in vivo assays in mice is most commonly used to assess a specific cannabinoid activity at the behavioral level. Thus, when a given compound produces motor depression in an open field, catalepsy on an elevated ring, analgesia on a hot plate, as well as hypothermia, cannabinoid CB1 receptor activation is assumed, although exceptions are possible. The full cannabinoid profile, however, includes for example ataxia in dogs and discrimination learning in rats. In view of (1) the addictive/reward potential of cannabis and the cannabinoids and (2) the multiple roles of the endocannabinoid physiological control system (EPCS) in behavioral functions, including memory, emotionality, and feeding, a number of behavioral techniques have been used to assess the effects of cannabinoids in these functions. In this chapter we will describe the tetrad of cannabinoid-induced effects as well as a series of behavioral assays used in the behavioral pharmacology of marijuana-cannabinoid research. Since the EPCS plays an important role in the developing organism, methods used in the assessment of physical and behavioral development will also be discussed. The techniques include the tetrad, drug discrimination, self-stimulation and self-administration, conditioned place preference/aversion, the plus-maze, chronic mild stress (CMS), ultrasonic vocalizations, cognitive behaviors, and developmental assessment in mouse (and rat) pups.
For centuries, hashish and marihuana, both derived from the Indian hemp Cannabis sativa L., have been used for their medicinal, as well as, their psychotropic effects. These effects are associated with the phytocannabinoids which are oxygen containing C21 aromatic hydrocarbons found in Cannabis sativa L. To date, over 120 phytocannabinoids have been isolated from Cannabis. For many years, it was assumed that the beneficial effects of the phytocannabinoids were mediated by the cannabinoid receptors, CB1 and CB2. However, today we know that the picture is much more complex, with the same phytocannabinoid acting at multiple targets. This contribution focuses on the molecular pharmacology of the phytocannabinoids, including Δ9-THC and CBD, from the prospective of the targets at which these important compounds act.
Apart from having been used and misused for at least four millennia for, among others, recreational and medicinal purposes, the cannabis plant and its most peculiar chemical components, the plant cannabinoids (phytocannabinoids), have the merit to have led humanity to discover one of the most intriguing and pleiotropic endogenous signaling systems, the endocannabinoid system (ECS). This review article aims to describe and critically discuss, in the most comprehensive possible manner, the multifaceted aspects of 1) the pharmacology and potential impact on mammalian physiology of all major phytocannabinoids, and not only of the most famous one Δ(9)-tetrahydrocannabinol, and 2) the adaptive pro-homeostatic physiological, or maladaptive pathological, roles of the ECS in mammalian cells, tissues, and organs. In doing so, we have respected the chronological order of the milestones of the millennial route from medicinal/recreational cannabis to the ECS and beyond, as it is now clear that some of the early steps in this long path, which were originally neglected, are becoming important again. The emerging picture is rather complex, but still supports the belief that more important discoveries on human physiology, and new therapies, might come in the future from new knowledge in this field.
Alleviation of neuropathic pain by cannabinoids is limited by their central nervous system (CNS) side effects. Indole and indene compounds were engineered for high hCB1R affinity, peripheral selectivity, metabolic stability, and in vivo efficacy. An epithelial cell line assay identified candidates with <1% blood-brain barrier penetration for testing in a rat neuropathy induced by unilateral sciatic nerve entrapment (SNE). The SNE-induced mechanical allodynia was reversibly suppressed, partially or completely, after intraperitoneal or oral administration of several indenes. At doses that relieve neuropathy symptoms, the indenes completely lacked, while the brain-permeant CB1R agonist HU-210 (1) exhibited strong CNS side effects, in catalepsy, hypothermia, and motor incoordination assays. Pharmacokinetic findings of ~0.001 cerebrospinal fluid:plasma ratio further supported limited CNS penetration. Pretreatment with selective CB1R or CB2R blockers suggested mainly CB1R contribution to an indene’s anti-allodynic effects. Therefore, this class of CB1R agonists holds promise as a viable treatment for neuropathic pain.
Since the isolation and structure elucidation of delta-9-THC by our group in 1964, numerous investigations have addressed the structure-activity relationships (SAR) in the cannabinoid series. The rules established in the 1970s have mostly withstood the erosion of time. However, the SAR rules as regards stereochemistry were developed much later. It was shown that in THC-type cannabinoids activity resides exclusively in the (−)cannabinoids with the 6aR, 10aR stereochemistry, as found in natural (−) delta-9-THC. This important observation was one of the factors that led to research that culminated in the identification of cannabinoid receptors. X-ray crystallography and detailed NMR investigation have made possible the establishment of the geometry of the active cannabinoids both in the solid-state and in solution. This geometry is presented now in some detail.
Among the drugs of abuse which are regulated under the United States Controlled Substances Act and the International Conventions, none has created more intense public debate and controversy than marihuana. Marihuana is one of many names given to the leaves and flowering tops of the plant Cannabis sativa. The plant grows in all temperate regions of this planet and has been used commercially as a source of fiber and oil. Wherever the plant grows people have learned to ingest the material for its introxicating effects. The usual routes of administration are by mouth or smoking. It has been estimated that, worldwide, more than one hundred million individuals are regular users of the plant material. However, accurate data on this situation are not available. In the United States, use data have been collected on a regular basis using two large surveys, the National Household Survey on Drug Abuse (SUBSTANCE ABUSE
AND MENTAL HEALTH SERVICES ADMINISTRATION 1994) and the Monitoring the Future Survey (JOHNSTON et al. 1994) which covers eighth, tenth, and twelfth grade students in public and private schools. Figure 1 presents the data over time for lifetime, annual, 30 day, and daily use of marihuana among high school seniors in the United States (JOHNSTON et al. 1994). As can be seen, use peaked from 1978 to 1980 and had been declining slowly up to 1992. From 1992 to 1993 there was a significant increase in all use categories. Even more disturbing was the fact that very similar trend data were reported for eighth and tenth graders. This was matched in 1992 and 1993 by a decrease in the reported “perceived risk” from use of the drug.
Two types of endogenous cannabinoid-receptor agonists have been identified thus far. They are the ethanolamides of polyunsaturated fatty acids--arachidonoyl ethanolamide (anandamide) is the best known compound in the amide series--and 2-arachidonoyl glycerol, the only known endocannabinoid in the ester series. We report now an example of a third, ether-type endocannabinoid, 2-arachidonyl glyceryl ether (noladin ether), isolated from porcine brain. The structure of noladin ether was determined by mass spectrometry and nuclear magnetic resonance spectroscopy and was confirmed by comparison with a synthetic sample. It binds to the CB(1) cannabinoid receptor (K(i) = 21.2 +/- 0.5 nM) and causes sedation, hypothermia, intestinal immobility, and mild antinociception in mice. It binds weakly to the CB(2) receptor (K(i) > 3 microM).
Perspective:
This study provides further in vivo evidence that mitochondrial dysfunction is a key contributor to the development and maintenance of chemotherapy-induced painful neuropathy. This work also indicates that selective modulation of the electron transport chain can induce antinociceptive effects in a preclinical model of paclitaxel-induced pain.
Background and Objectives: Phloroglucinols are secondary metabolites that occur naturally in certain plant species. Microorganisms such as brown algae or bacteria also produce phloroglucinols. Phloroglucinols has potential health effect and it is used as a treatment for gallstones, spasmodic pain and other related gastrointestinal disorders. The objective of the study was to evaluate phloroglucinol and its tri-methyl ether for anti-stress activity and its beneficial effect on stress-induced perturbations. Method: Stress-induced hyperthermia and pentobarbital sedation models were used for pilot study cum relative dose response study at single and repeated per-oral doses of 3-300 mg kg‾1 day‾1. Further study was performed to evaluate phloroglucinol (1-16 mg kg‾1 day‾1, p.o., for 7 days) for anti-stress activity using validated animal models of stress viz., foot-shock stress and cold-restraint stress. Stress-induced perturbations were evaluated in stressed rats by using sexual behaviour, elevated zero maze and behavioural despair tests. Results: The observations revealed that phloroglucinol and its tri-methyl ether protect mice against stress-induced hyperthermia only after its daily administrations. After fairly low oral doses, phloroglucinol inhibited not only stress-induced gastric ulcers but also the exaggerated anxiety and depression observed in stressed animals. In the same dose range, it also improved sexual behaviour and suppressed adrenal hypertrophy and spleen atrophy in stressed animals. Conclusions: These observations strongly suggest that plasma or urinary levels of phloroglucinol are not proper indicators of its therapeutic benefits and that its observed anti-stress activity could as well be due to its actions on the microbiota-gut-brain axis.
Cannabinoids produce a characteristic profile of in vivo effects in mice, including suppression of spontaneous activity, antinociception, hypothermia, and catalepsy. Measurement of these four properties, commonly referred to as the tetrad test, has played a key role in establishing the structure-activity relationship of cannabinoids acting at cannabinoid CB1 receptors. The purpose of this study was to determine whether drugs acting at noncannabinoid CB1 receptors produced a similar pharmacological profile. Mice were tested in this paradigm after being injected with Δ9-tetrahydrocannabinol and selected drugs from other drug classes. Δ9-Tetrahydrocannabinol dose-dependently produced all four effects with reversal by the cannabinoid CB1 receptor antagonist N-(piperidin-1-yl)-5-(4-chlorophenyl)-1-(2,4-dichlorophenyl)-4-methyl-1H- pyrazole-3-carboxamide hydrochloride (SR 141716A). Amphetamine, scopolamine, morphine, desipramine, pimozide, pentobarbital, ethanol, and diazepam were not fully active in at least one of the tests. Antipsychotics showed the greatest similarity to those of cannabinoids in the tetrad tests, although there were also distinct differences. Clozapine, haloperidol, thioridazine, and chlorpromazine (but not pimozide) were fully active in all four tests; however, unlike with Δ9-tetrahydrocannabinol, their effects were not blocked by SR 141716A. Further, whereas antipsychotics produced nearly 100% catalepsy, maximal catalepsy produced by Δ9-tetrahydrocannabinol was 60%. The mechanism through which antipsychotics produce these effects in mice is uncertain, but it differs from cannabinoid CB1 receptor activation that mediates the effects of cannabinoids. While results of previous research suggest that the tetrad tests are a useful tool in examination of structure-activity relationships of cannabinoid CB1 receptor agonists, the present results suggest that they must be used cautiously in the search for novel cannabinoid receptors.
In this report we give the results of some experiments on the effects of the hashish constituents δ9-tetrahydrocannabinol (THC) and cannabidiol (CBD) on mice. THC produced a dose dependent depression of aggression in isolated mice and a dose dependent depression of body temperature in group caged mice. The drug did not alter motor co-ordination. CBD showed a small, not significant influence on aggressiveness, and no influence on body temperature and muscle control. The same experiments were carried out with combinations of THC and CBD in several dosages.
In these experiments no interaction between both compounds was seen. This means that there can only be an additive action and not potentiation in the pharmacological sense. It also means that the in vitro inhibition by CBD of the drug metabolizing enzymes, responsible for biotransformation of THC, is not strong enough to result in changed effects of THC in the living animal.
The n-propyl homologue of Δ1-tetrahydrocannabinol (Δ1-THC) has been isolated from Cannabis sativa L. The structure of the compound was deduced by i.r., n.m.r., and mass spectroscopy, and was confirmed by synthesis. It has only one-fifth of the activity of Δ1-THC in the mouse catalepsy test, and although present in amounts comparable to Δ1-THC it probably makes only a small contribution to the effects produced by the consumption of crude cannabis.
A study of the central action of six cannabinoids has been carried out. The compounds studies (see table) were (−)Δ9THC and (−)Δ8THC, the racemic Δ8THC, the α methyl, and α, α dimethyl derivatives of (−)Δ8THC, and (−)cannabidiol. The effects of these drugs have been studied on the cerebral electrical activity and on spontaneous and conditioned behavior of cats, rabbits, and rats with chronically implanted electrodes. In the rabbit and in the rat, (−)Δ9THC, (−)Δ8THC, and the two methylated derivatives of (−)Δ8THC proved to have a similar effect; they induced a flattening of the EEG tracing, the disruption of the theta waves of the hippocampus and they gave rise to trains of high voltage spike-and-waves. These EEG modifications were accompanied by corneal arreflexia and other signs of motor deficit, together with a state of excitation and a reduced response to painful stimuli. The racemic Δ8THC, although provoking the same picture, proved less active. (−)Cannabidiol provoked motor paralysis and corneal arreflexia, these symptoms were accompanied by an EEG synchronization. In the cat, the performance of a conditioned instrumental discrimination exercise was blocked by the administration of 2 mg/kg of Δ9THC; this effect was accompanied by a synchronization of the EEG. These results are discussed also in relation to the human effect of some of these compounds. It is suggested that the flattening of the EEG and the appearance of the spike-and-waves may be the EEG counterpart of the psychodysleptic action of the tetrahydrocannabinols in man.
Administration of pure 1-δ9-tetrahydrocannabinol to mice had the following dose-dependent nzeurochemical and behavioral effects: a slight but significant
increase in concentrations of 5-hydroxytryptamine in whole brain; a decrease in concentration of norepinephrine in brain after
administration of low doses and an increase after high doses; diminished spontaneous activity, mloderate hypothermnia, hypersetisitivity
to tactile and auditory stimiuli, and ataxia after low doses; and sedation, pronounced hypothermia, and markedly diminished
spon taneous activity and reactivity after high doses. The duration of the effects on body temperature and spontaneous activity
correlated generally with the changes in brain amines. The characteristic changes in brain amines do not correspond exactly
to those observed with other psychotropic drugs.
THERE have been few reports concerning the chemistry and pharmacology of marijuana and its constituents1,2, and most investigators have studied the natural product or a crude extract. Mechoulam and co-workers3 isolated Δ9-tetrahydrocannabinol, which is believed to be the most active constituent of marijuana and has been shown to have marijuana-like activity in man4. Subsequently, Δ8-tetrahydrocannabinol was purified and now both isomers have been prepared synthetically and are available in small quantities for pharmacological experimentation. These substances are somewhat unique in that there are few agents which have such a profound effect on the central nervous system yet do not contain either a sulphur or nitrogen atom in the molecule. We report here some preliminary pharmacological results with pure synthetic Δ8 and Δ9-tetrahydrocannabinol (Δ9-THC), and also describe the effect of the insertion of a heterocyclic atom in ring C on the pharmacology of these agents. The nitrogen analogue of Δ9-THC (I in Fig. 1) was synthesized by Pars and co-workers5 and the sulphur analogue (II) by R. K. R. (unpublished data).
Cannabis extract prolonged sleeping time in mice in a thermally neutral environment (30–32° C) in which hypothermia does not occur. The prolongation was dose related, just detectable at 50 mg/kg, and 4‐fold at 500 mg/kg.
Under these conditions, ether sleeping time was not prolonged.
Cannabis extract inhibited the aerobic metabolism of phenazone by a microsome‐rich 9,000 g supernatant of mouse liver homogenate capable of nicotinamide adenine dinucleotide phosphate (NADPH) generation.
Δ ¹ ‐Tetrahydrocannabinol (Δ ¹ ‐THC) prolonged pentobarbitone sleep and inhibited phenazone metabolism, but its action was limited, and could not account for the effect of the extract. The carotenes and water‐soluble fractions of the extract were inactive on pentobarbitone sleep.
Cannabidiol was strongly active by both tests; in vivo 39·8 μ m /kg (12·5 mg/kg) prolonged sleep by 190%, and in vitro 12·7 μ m inhibited phenazone metabolism 20%. These actions were dose related, and could account for the effect of the extract.
The prolongation of pentobarbitone sleep by cannabis extract in a dose of 200 mg/kg, intraperitoneally, was maximal when given 30 min before the pentobarbitone, still present at 3 h, but undetectable at 24 hours. No phase of enhanced metabolism at 24 or 48 h after single cannabis injection was detected.
It is concluded that cannabis extract inhibits microsomal activity of mouse liver, chiefly by virtue of its cannabidiol content. It is probable that cannabis consumption by man could lead to altered disposal of many other drugs, used in medicine or otherwise.
Both dl-Delta(8)- and dl-Delta(9)-tetrahydrocannabinol produced marked alterations of behavior in rhesus and squirrel monkeys. Squirrel monkeys appeared to have visual hallucinations. Continuous avoidance behavior of squirrel monkeys was stimulated by both drugs, but high doses of dl-Delta(9)-tetrahydrocannabinol also caused depression after the stimulant phase. Complex behavior involving memory and visual discrimination in rhesus monkeys was markedly disrupted by both drugs.
1.The psychopharmacological activity of ?1-tetrahydrocannabinol, (I); ?1(6)-tetrahydrocannabinol (4' hexyl), (II); ?1(6)-tetrahydrocannabinol, (III); 1-ethoxyhexahydrocannabinol, (IV); 8-ethoxy-iso-hexahydrocannabinol, (V); ?1(6)-tetrahydrocannabinolic acid Me ester, Isomer I, (VI); ?1(6)-tetrahydrocannabinolic acid Me ester, Isomer II, (VII); cannabigerol, (VIII); ?1(6)-tetrahydrocannabinol (3' hexyl), (IX); cannabichromene, (X); has been examined in a variety of animal species.2.Compounds (I) and (III) caused severe motor disturbances and a stuporous state in dogs and ptosis, “tameness” and peculiar postural changes in monkeys. In the latter animal, compound (II) elicited similar effects.3.Compounds (I) and (III) after intraperitoneal but not subcutaneous administration, suppressed the gerbil digging activity; reduced the rat conditioned avoidance response and induced a cataleptoid reaction in mice, rats and gerbils. In addition, compound (I) reduced the performance of mice on the rotating-rod. Both compounds, administered subcutaneously, induced a measurable ataxic gait in rats.4.Amphetamine reversed the behavioural changes elicited by compounds (I) and (III) in monkeys, as well as the cataleptoid reaction in rats.5.None of the other compounds provoked observable changes in any of the species studied.6.It is suggested that Rhesus monkeys might serve as a suitable model for assessing the psychopharmacological activity of active cannabinoids.
The effect of pretreatment with cannabidiol (CBD; 50 mg/kg i.p.) on the distribution of radioactivity in chromatograms of ethyl acetate extracts of the brains of mice injected with tritiated Delta(1)-tetrahydrocannabinol ((3)H-Delta(1)-THC; 1.0 mg/kg i.v.) was determined. The pretreatment with CBD produced significant increases in the levels of radioactivity in the brain assigned to Delta(1)-THC and its centrally active metabolite 7-hydroxy-Delta(1)-THC: the changes produced were respectively 1.4 and 2.0 fold.Pretreatment with CBD did not bring about any detectable change in the degree of 'catalepsy' produced by Delta(1)-THC. This negative finding may have been due to the wide limits of error that were obtained in the bioassay.
There are at least six pharmacologically effective components of cannabis. Their effects on mice include a lowering of body temperature, catalepsy, analgesia and an extension of barbiturate sleeping time, with doses from 25 to 200 mg/kg.
The structure activity relationships of four tetrahydrocannabinols and the pharmacological activity of five semi-purified extracts from Cannabis sativa were studied using four biological methods: corneal areflexia in rabbits (Gayer test) and catatonia, decrease of motor activity and suppression of isolation-induced aggressiveness in mice. Modifications in the structure of pure, natural Δ9-THC rendered the resultant compounds inactive only when activity was measured by the Gayer test; by the other three methods the activity ranged from 1/5th to equal to the activity of pure Δ
9-THC. It was concluded that of the methods employed, the Gayer test was the only useful procedure to measure Δ
9-THC content in mixtures. This was confirmed by the relationship found between Δ
9-THC content and activity using five semi-purified extracts.
The 11-hydroxy metabolites of Δ8.- and Δ9-tetrahydrocannabinol are more active than the parent compounds when administered to mice by either the intravenous or intracerebral
route. Both Δ8- and Δ9-tetrahydrocannabinol are rapidly and extensively metabolized by the liver and not by the brain. The hypothesis that the 11-hydroxy
metabolites may be the active form of tetrahydrocannabinol is discussed
Further studies on the actions of marihuana (Cannabis sativa) have been reported. An extract of marihuana, natural tetrahydrocannabinol, and two synthetic tetrahydrocannabinols were investigated for depressant or stimulant actions. Sleeping times after sodium hexobarbital and measurement of motor activity after amphitamine administration in mice pretreated with the drugs were used to determine the stimulant or depressant properties, respectively.Natural tetrahydrocannabinol and both synthetic tetrahydrocannabinols significantly prolonged hexobarbital sleeping time, while natural tetrahydrocannabinol, 3-n-amyl tetrahydrocannabinol, and the marihuana extract significantly increased the activity induced by amphetamine. Natural THC and synthetic 3-n-amyl decreased normal activity, but later increased it over that of controls.
Nouveaux aspects exp6rimentaux de l'activit6 centrale des derives de la ph6nothiazine Pharmacology of some marijuana constituents and two heterocyclic analogues
- S Courvoiser
- R Ducrot
- L Julou
- S Garratini
- V Ghetti
- W L Dewey
- L S Harris
- J F Howes
- J S Kennedy
- F E Granchelli
- H G Pars
- R K Razdan
COURVOISER, S., DUCROT, R. & JULoU, L. (1957). Nouveaux aspects exp6rimentaux de l'activit6 centrale des derives de la ph6nothiazine. In: Psychotropic Drugs, ed: Garratini, S. & Ghetti, V., Amsterdam: Elsevier Publishing Co. DEWEY, W. L., HARRIS, L. S., HowEs, J. F., KENNEDY, J. S., GRANCHELLI, F. E., PARS, H. G. & RAZDAN, R. K. (1970). Pharmacology of some marijuana constituents and two heterocyclic analogues. Nature, Lond., 226, 1265-1267.
Activity of A8-and A9-tetrahydrocannabinol and related compounds in the mouse
- H D Christensen
- R I Freudenthal
- J T Gidley
- R Rosenfeld
- G Boegli
- L Testino
- D R Brmu
- C G Prrr
- M E Wall
CHRISTENSEN, H. D., FREUDENTHAL, R. I., GIDLEY, J. T., ROSENFELD, R., BOEGLI, G., TESTINo, L.,
BRmu, D. R., Prrr, C. G. & WALL, M. E. (1971). Activity of A8-and A9-tetrahydrocannabinol
and related compounds in the mouse. Science, N.Y., 172, 165-167.