Ayahuasca Technical Report 2017

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Ayahuasca
Technical Report 2017
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!
José Carlos Bouso, Ph.D. Clinical Psychologist, Doctor in Pharmacology!
International Center for Ethnobotanical Education, Research & Service, Spain!
!
Rafael Guimarães dos Santos, Ph.D. Biologist. Doctor in Pharmacology !
Department of Neurosciences and Behavior, Ribeirão Preto Medical School, !
Universidade de São Paulo, Brazil!
!
Charles S. Grob, M.D.!
Harbor-UCLA Medical Center, USA!
!
Dartiu Xavier da Silveira, M.D.!
Universidad Federal de São Paulo, Brazil!
!
Dennis Jon McKenna, Ph.D. Doctor in Botany!
Center for Spirituality and Healing, University of Minnesota, USA!
!
Draulio Barros de Araujo, Ph.D. Doctor in Neurology!
Brain Institute UFRN, Brazil!
!
Jordi Riba, Ph.D. Doctor in Pharmacology!
Experimental Neuropsychopharmacology Research Group, Sant Pau Hospital Barcelona, Spain !
!
Paulo Cesar Ribeiro Barbosa, Ph.D. Doctor in Medical Sciences !
Universidade Estadual de Santa Cruz, Brazil !
!
Constanza Sánchez Aviléz, Ph.D. Doctor in International Relations and International Law!
International Center for Ethnobotanical Education, Research & Service, Spain!
!
Beatriz Caiuby Labate, Ph.D. Doctor in Anthropology!
Center for Research and Post Graduate Studies in Social Anthropology, Mexico

1. What is ayahuasca?
Ayahuasca is the Quechua word referring to a liquid produced by the slow decoction of the
Amazonian Banisteriopsis caapi vine – as well as to the vine itself – which contains harmine,
harmaline and tetrahydroharmine. It is traditionally used throughout the Northwestern Amazon,
originating from indigenous cultures that have used it for hundreds of years for medicinal and ritual
purposes. At the beginning of the last century, syncretic religions combining Amerindian
shamanism, African religiosity, European esotericism, and Christianity began to use ayahuasca. In
the 1980s, these churches expanded from the Amazon into Brazilian urban centers (Labate 2004)
and, since the 1990s, globally (Labate & Jungaberle, 2011).
Based on the intended use of the decoction of the vine called ayahuasca, Amazonian group or
healer with experience using ayahuasca, adds different plants to the decoction with the objective of
communicating with a specific spirit depending on the disease to be healed or ritual to be
performed. Ethnographic studies suggest that there are more than 5000 different recipes of
ayahuasca (Fericgla, 1997) and more than 200 admixture plants to ayahuasca, all using B. caapi
as their base (McKenna et al., 1986). Some of the traditional recipes involving ayahuasca,
considering both the indigenous cultures and the religions that use ayahuasca as their sacrament
(or “ayahuasca religions”), include adding leaves of the Psychotria viridis bush, which contains
DMT (N,N-Dimethyltryptamine), along with the B. caapi vine (Schultes & Hofmann, 1992).
Ayahuasca is currently being popularized as the combination of B. caapi and P. viridis, likely
because the international expansion of ayahuasca practices was initiated by these churches
(Sánchez y Bouso, 2015).
The precise historical beginning of ayahuasca use is unknown."The oldest traces of possible
ayahuasca use have been found in the Azapa desert in the north of Chile, where harmine residues
have been found in hair analyzed from mummies from the Tiwanaku period between 500 and 1000
C.E. The B. caapi vine does not grow in the Azapa valley, nor do any other harmine-containing
plants, which suggests well-established commerce between the ancient populations of the Andes
and the Amazonian peoples; probably the former provided the latter with salt and the latter
provided the former with medicines, among them ayahuasca. Among Amazonian ethnic groups,
the use of ayahuasca decoctions that also contain plants with DMT seems to be a more recent
phenomenon (Brabec de Mori, 2011).
Ayahuasca is considered a sacred drink by innumerable indigenous Amazonian groups and a
medicine by mestizo healers in several parts of South America."The traditional and modern use of
ayahuasca extends from Panama to Bolivia, including Peru, Ecuador, Colombia, and Brazil –
countries in which its medicinal use is present also in urban centers"(Luna, 1986, 2011). A
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pioneering 1986 work that brought together all the scientific information on ayahuasca available at
that time found more than 400 bibliographical references on the ethnography of ayahuasca (Luna,
1986b), references to more than 70 different Amazonian ethnic groups where it was used
traditionally, and more than 40 vernacular names given to the decoction (Luna, 1986c). Ayahuasca
is currently being used as a medicine in ceremonies officiated by indigenous peoples, mestizos,
and diverse professionals who have learned to use it in its places of traditional origin"(Labate &
Bouso, 2013; Labate & Cavnar 2014a; Labate, Cavnar & Gearin, 2017; Labate et al., 2009; Luna,
2011).
2. The legal status of ayahuasca
As noted above, ayahuasca is typically produced by the slow decoction of two plants – B. caapi
and P. viridis. The latter of these two plants contains DMT (N,N-dimethyltryptamine), a tryptamine
alkaloid listed in the 1971 Convention on Psychotropic Substances, and many countries therefore
also include it in their national legislation. Although DMT is listed in Schedule 1 in the Conventions
(the most restrictive category), the International Narcotics Control Board (INCB), a quasi-judicial
control body for the implementation of the United Nations drug conventions, has stated on several
occasions that ayahuasca – as well as other psychoactive plants – are not subject to international
control.
In their 2010 Annual Report, the INCB stated that “[…] although some active stimulant or
hallucinogenic ingredients contained in certain plants are controlled under the 1971 Convention, no
plants are currently controlled under that Convention or under the 1988 Convention. Preparations
1
(e.g. decoctions for oral use) made from plants containing those active ingredients are also not
under international control” (paragraph 284, INCB, 2010).
The alkaloids present in the B. caapi vine are also not subject to international control."In 2008,
ayahuasca was declared Cultural Patrimony of Peru, due to its ancestral use as a traditional
medicine"(Instituto Nacional de Cultura, 2008) and its use for religious purposes is firmly
established and legalized in Brazil (Labate et al., 2009). The religious use of ayahuasca on the part
of certain churches is also legally protected and regulated in Holland and the United States, and
the churches in which ayahuasca is considered a sacrament and is consumed for that purpose
The Article 1 from the 1971 Convention, which is dedicated to specify the terms used in the treaty, understands as
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preparation: “1) Any solution or mixture, in whatever physical state, containing one or more psychotropic substances, or
2) One or more psychotropic substances in dosage form.” Therefore, since ayahuasca is a decoction of plants that are
not controlled, and not a mixture of active principles, then the term “preparation,” according to the definition of the treaty,
is not appropriate when referring to ayahuasca (Art. 1, f) i)).
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have expanded internationally into numerous European, American, and Asian countries (Labate et
al., 2009; Labate & Feeney, 2012; Sánchez & Bouso, 2015).
In terms of Spain, upon the request of lawyers working on ayahuasca-related cases, the Spanish
Agency of Medicinal Products and Medical Devices (AEMPS) issued letters confirming that
although DMT is a controlled substance according to the 1971 Convention on Psychotropic
Substances, ayahuasca is not subject to control by Spanish legislation (e.g. AEMPS, 2013).
3. The pharmacology of ayahuasca
The mechanism of action by which ayahuasca produces its effects is highly sophisticated."The
harmala alkaloids (harmine, harmaline and tetrahydroharmine) have the property of acting as
inhibitors of monoamine oxidase (MAO), an enzyme present in the gastrointestinal tract that
degrades monoamines."As DMT is a monoamine, if it is ingested orally, the endogenous MAO
deactivates it, preventing it from reaching the brain."At some point in the remote past, the
indigenous people of the Amazon Basin discovered that adding the leaves of Psychotria viridis
(which, as previously mentioned, contain DMT) to a decoction of Banisteriopsis caapi (which
contains harmala alkaloids), makes the DMT bioactive."This is due to the harmala alkaloids, which,
acting as MAO inhibitors (MAOIs), block the MAO present in the gastrointestinal tract and in this
way the DMT present in the leaves of P. viridis can reach the brain (Mckenna et al., 1984; Riba et
al., 2003)."Pure DMT on its own is inactive when consumed orally (Riba et al., 2015). This
sophisticated indigenous discovery was only recently rediscovered by science in the 1980s."DMT
is found in its natural form in many animal species"(Shulgin & Shulgin, 1997) and in human urine,
blood, and cerebrospinal fluid"(Barker et al., 2012). Its physiological role remains unknown.
During the last few decades, clinical trials have been carried out on humans where both DMT (in
purified form, administered intravenously) and ayahuasca (administered orally) have been
administered in a laboratory context, and their acute effects have been characterized both at the
psychological and somatic levels."In these studies, it has been demonstrated that DMT and
ayahuasca have very different pharmaco-dynamics."The acute effects of DMT appear in an intense
and almost immediate way after its intravenous administration (Strassman & Qualls, 1994;
Strassman et al., 1994), while ayahuasca produces effects in a slower and more progressive way,
beginning from 45 to 60 minutes after administration, reaching maximum effects after 2 hours,
which disappear after 4 to 6 hours (Riba, 2003; dos Santos, 2011)."The maximum intensity of the
effects of DMT is approximately two times that of ayahuasca at equivalent doses"(Grob et al.,
1996), which makes the global effects of ayahuasca much more controllable than pure DMT."In
addition, since ayahuasca is a decoction made with plants there are also other compounds (beta-
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carbolines) that may modulate the effects and thus make them significantly different from pure
DMT.
4. The effects of ayahuasca
Ayahuasca, whether administered in a laboratory context or ingested in a traditional context,
produces transitory modifications in emotion, thought content, perception and somatic sensations
– as evaluated through questionnaires to measure its subjective effects – while the capacity of the
individual to interact with its surroundings is significantly preserved (Grob et al.,1996; Riba et al,
2001, 2003; dos Santos et al, 2011, 2012), even to the point of being able to carry out complex
cognitive performance tests (Bouso et al., 2013)."The volunteers in these studies also describe the
effects of ayahuasca as "well tolerated" (Riba et al., 2001, 2003; dos Santos et al., 2011, 2012).
The curve of effects that ayahuasca produces corresponds with the curve of the presence of DMT
and harmalines (MAOIs) in plasma, which disappears from the organism after eight hours (Riba et
al., 2003; Schenberg et al., 2015)."
Studies have been published where neuroimaging techniques were used to determine which
cerebral areas are activated after the ingestion of ayahuasca."Two studies showed that ayahuasca
activates the cortical and paralimbic areas."Specifically, in the first of these studies"(Riba et al.,
2006), bilateral increments in cerebral perfusion were found in the"inferior frontal gyrus and the
anterior insula, the activity being most intense in the right hemisphere. Activations in the anterior
cingulate and medial frontal cortex in the right hemisphere, areas involved in awareness of
interoceptive and emotional processes, as well as emotional arousal, were also found. Increased
cerebral blood flow in the ventral anterior cingulate gyrus and the subcallosal was also recorded,
structures that are related to decision-making and emotions. The left amygdala, a structure
involved in the processing of potentially threatening stimuli, and the parahippocampal convolution,
a structure associated with the hippocampus and intimately involved in the processing of
memories, also showed higher blood perfusion compared to placebo. No differences were found
compared to placebo in any other area of the brain.
In another second neuroimaging study performed with Functional MRI (fMRI), activation in primary
visual areas was also found, and when subjects under the influence of ayahuasca were
remembering a photograph its magnitude was comparable to baseline activation levels recorded
with the presentation of a natural image with eyes open (de Araujo et al., 2011). According to the
authors, this effect causes the brains of volunteers to interpret the ayahuasca experience as if it
was "real," not in the sense of a hallucinatory experience, but by the experiential endowment of
conscious experience. This overall pattern of activation may be at the base of the introspective
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processes, memories of past experiences charged with emotional"connotations, and complex
cognitive processes, which are so prototypical of the ayahuasca experience (Shanon, 2002).
In fact, a recent fMRI study showed a deactivation of a neural network known as the Default Mode
Network (DMN) (Palhano-Fontes et al., 2015). This network, which includes different brain
structures, is thought to be involved in internal mental processes, such as the sense of “I,” or the
mental imagery produced when a person is in a state of relaxation. Abnormal increases in DMN
activity were observed in a wide spectrum of neurological disorders such as autism, Parkinson’s
and Alzheimer’s disease, and psychiatric disorders such as schizophrenia and depression. In this
study, it was observed that ayahuasca decreased DMN activity, a finding also observed with other
substances of similar psychoactivity, such as psilocybin (Carhart-Harris et al., 2012).
When considered together, these cerebral, cognitive, and emotional phenomena could explain why
ayahuasca is considered an ethnobotanical tool with psychotherapeutic potential (Labate &
Cavnar, 2014b). In fact, one study found that ayahuasca reduced panic and hopelessness scores
in experienced users (Santos et al., 2007).
5. Long-term effects
Studies of medium- and long-term ayahuasca use have shown evidence of either
neuropsychological or psychopathological alterations associated with the continuous use of
ayahuasca. One prospective study conducted among people that ingested ayahuasca for the first
time showed improvements on mental health measures and physical pain reduction for six months
after initiation to ceremonial ayahuasca use (Barbosa et al., 2005, 2009). Other studies have
shown better indicators of psychopathology and higher psychosocial wellness among regular
ayahuasca users (Bouso et al., 2012; Halpern et al., 2008) and three studies did not find
neuropsychological alterations measured with cognitive performance tests among regular users of
ayahuasca after years of continuous use (Grob et al., 1996; Barbosa et al., 2016; Bouso et al.,
2012; Bouso et al., 2015). One of these studies compared 127 ayahuasca users with a history of
ritual ayahuasca use of at least 15 years with 115 controls, and observed better scores on
psychopathological measures and in some neuropsychological tests among the ayahuasca users
– results that remained consistent in two evaluations separated by one year (Bouso et al., 2012).
Studies with adolescent members of a Brazilian UDV church also failed to observe any
neuropsychological or psychiatric alterations associated with ritual ayahuasca use (da Silveira et
al., 2005: Doering-Silveira et al., 2005b).
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Finally, a recent neuroimaging study with Spanish members of the Santo Daime church with
participants who had a history of ayahuasca use of at least 50 occasions in the past two years
found differences on cortical thickness among the ayahuasca users compared to a control group.
Differences in cortical thickness were only correlated with the personality variable “Self-
Transcendence,” suggesting that ayahuasca may produce brain alterations that could manifest as
increased spiritual tendencies (Bouso et al., 2015). Ayahuasca users in this study had similar
scores to the control group of non-users on psychopathological tests and on neuropsychological
function, showing that the structural changes possibly associated with ayahuasca use did not
relate to brain toxicity, but to personality changes that simply reflect a “different,” but not
pathological, way of being, as has been shown in several previously cited studies (Grob et al.,
1996; Barbosa et al., 2009 Barbosa et al., 2016; Bouso et al., 2012; da Silveira et al., 2005;
Doering-Silveira et al., 2005b; Halpern et al., 2008). These kinds of brain alterations are also
known to be produced through training and practice in numerous activities, such as learning music,
and are known as cerebral plasticity – a normal phenomenon that occurs in our brains
continuously throughout our lives.
6. Adverse effects
Some adverse effects associated with ayahuasca administration in laboratory contexts have been
reported, although these were rare and isolated cases that were resolved without the need for
intervention (Riba & Barbanoj, 2005). There are some cases describing psychiatric
symptomatology in ritual contexts, although these cases are rare (Lima & Tófoli, 2011; dos Santos
& Strassman, 2011) and their occurrence seems to be below the prevalence of psychiatric
problems in the general population. In any case, these data suggest that ayahuasca is, in principle,
contraindicated for people with grave psychiatric disorders, particularly those individuals prone to
psychosis.
Although ayahuasca is psychoactive, this does not mean that the doses that are usually ingested
in sessions produce organic or brain toxicity. In this sense, and according to toxicology science,
the minimum psychoactive dose should not be equivalent to the toxic dose, if toxicity is considered
the capacity of a substance to induce harm to an organism by means of its chemical properties
after being in contact with the organism (Baños & Farré, 2002). Regarding the effects of
ayahuasca in the organism, studies performed with volunteers both in the laboratory (Riba, 2003;
dos Santos, 2011) and in natural contexts (McKenna, 2004) show that ayahuasca is physiologically
safe. The impact of ayahuasca on the cardiovascular system is minimal, producing only slight
increases in blood pressure and heart rate that have no clinical implications (Riba et al., 2001,
2003; dos Santos et al., 2012). It was also observed that ayahuasca induces transitory increases
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in the levels of the hormones prolactin, cortisol, and growth hormone (dos Santos et al., 2011,
2012), and with regards to the immune system, ayahuasca time-dependently reduces
subpopulations of CD4 and CD3 lymphocytes and increases natural killers (NK) cells (dos Santos
et al., 2011, 2012). These transitory physiological effects do not seem to have negative
consequences – in studies where general blood analysis were performed in subjects before and
after the participation in the trials, no hematological or biochemical alterations were found (Riba et
al., 2001; Riba & Barbanoj, 2005).
The main adverse effects produced by ayahuasca are nausea and vomiting (Callaway, et al., 1999;
Riba et al., 2001; Riba, 2003; Riba & Barbanoj, 2005; dos Santos, 2011; dos Santos et al., 2012).
The emetic action of ayahuasca is related first to the organoleptic properties of the decoction, and
second to its serotonergic action (Callaway et al., 1999). These are not considered important
adverse reactions by session participants, where they are understood as potential therapeutic
effects and called “la purga” (“the purge”) in traditional Amazonian medicine (Luna, 1986, 2011) or
“limpeza” (cleansing) in the context of the Brazilian ayahuasca religions (Labate, 2004). In
traditional contexts, the “purge” is understood as a physical and psychological cleansing from
internal conflicts that may distress the participant, and is considered an essential part of the
therapeutic benefits (Luna, 1986, 2011). The emetic effects of ayahuasca suggest that ayahuasca
is likely one of the main reasons it does not have a potential for recreational use.
7. The abuse potential of ayahuasca
Studies with healthy volunteers showed that ayahuasca does not produce tolerance (dos Santos et
al., 2012), thus it is not necessary to increase the dose to achieve the desired effects, which,
together with the emetic effects, protect consumers from overdose.
Regarding the abuse potential of ayahuasca, in the neuroimaging studies with healthy volunteers
described above, no activation of brain areas related to the reward systems was observed – the
brain areas activated by drugs with potential for abuse. Moreover, the available evidence suggests
that ayahuasca could be used as a tool for the treatment of drug dependence (Bouso & Riba,
2014). Indeed, there are several clinics in South America that specialize in the treatment of drug
dependence using ayahuasca, the most well-known being Takiwasi, in Peru (Mabit, 2007). In a
recent study conducted with patients with severe depression, researchers found that ayahuasca
activates a reward system in the brain called the nucleus accumbens, creating an effect that the
authors of the study found to be unique to patients with depression – a finding that contributes to
explaining the anti-depressant effects of ayahuasca in patients with severe depression.
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One of the first human studies on ayahuasca use showed that many participants of UDV church
rituals stopped using alcohol and other drugs, such as cocaine, as a result of their participation in
church rituals (Grob et al., 1996). These findings were also found in a subsequent study with
members of the Santo Daime church in Oregon, USA (Halpern et al., 2008). Another study with a
large number of participants, which compared 127 ayahuasca consumers with 115 controls – failed
to find evidence of drug dependence according to the biopsychosocial criteria of the ASI scale
(Addiction Severity Index, the standard scale to assess drug dependence), or evidence that the
continuous ritual use of ayahuasca was associated with harmful biopsychosocial consequences
related to drugs of abuse. Moreover, the ayahuasca group consumed less alcohol and other drugs
compared to the control group, and these scores on the biopsychosocial criteria for drug
dependence were replicated a year later, confirming the consistency of the results (Fábregas et al.,
2010). A study with adolescent members of the UDV church also found that the ayahuasca group
consumed less alcohol than the control group, concluding that rather than being associated with
drug dependence, ayahuasca use seemed to act as a protective factor regarding alcohol
consumption (Doering-Silveira et al., 2005a).
8. Therapeutic potential of ayahuasca
The therapeutic properties of ayahuasca are related to its effects on the brain – it activates
cerebral areas associated with memories of personal events (called episodic memory) and with the
conscious experience of emotions and internal sensations (Riba et al., 2006; de Araujo et al.,
2011). From a psychological perspective, a recent study showed that the therapeutic potentials of
ayahuasca might be related to its ability to increase what is called in clinical psychology
“decentering” (Soler et al., 2016), or the capacity to observe thoughts and emotions as transitory
events of the mind without being trapped by them. This process is considered important in clinical
psychology, because it can produce psychological changes in patients.
If ayahuasca does not have potential for recreational use or abuse, there must be other reasons
why people use it. Personality studies performed among Brazilian and Spanish ayahuasca users
did not find higher scores on a scale known as Novelty Seeking (Grob et al., 1996; Bouso et al.,
2012; Bouso et al., 2015), a personality trait for which users of drugs of abuse have high scores.
Nevertheless, ayahuasca users scored higher than controls on a personality trait called Self-
Transcendence (Bouso et al., 2012; Bouso et al., 2015), or the tendency to have a transcendent
concept of life, not necessarily associated with a religious affiliation. Taken together, these
personality studies have found that people who use ayahuasca do so for reasons that are related
to personal development, the search for psychological wellbeing, and adapting better to their
environment. Indeed, these studies reported that ayahuasca users are people perfectly adapted
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and integrated in their social, working, and familiar environments and that ayahuasca is used as a
tool for personal and spiritual improvement – findings that are similar to those observed among
people who practice meditation or other techniques for personal development and wellbeing (Soler
et al., 2016; Palhano-Fontes, 2015).
There are some studies that have explored the therapeutic potential of ayahuasca in psychiatric
populations. A recent study reported anti-depressant effects of ayahuasca in patients with major
depression, effects that were sustained for 21 days after the administration of a single dose
(Osório et al., 2015; Sanches et al., 2016). This therapeutic effect was associated with brain
changes measured with neuroimaging techniques, thus providing an objective demonstration of
therapeutic change (Sanches et al., 2016). Another more recent study confirmed the anti-
depressant effect of a single dose of ayahuasca within one day of the session, when compared
with a placebo (Palhano-Fontes et al., 2017). Other recent studies showed preliminary evidence of
efficacy in the treatment of drug dependence (Fernández et al., 2015; Labate y Canvar, 2014b;
Loizaga-Velder y Verres, 2014; Thomas et al., 2013). Although the research on the therapeutic
effects of ayahuasca is still nascent, several authors propose that ayahuasca could also be used to
treat posttraumatic stress disorder (PTSD) (Nielson and Megler, 2014) or antisocial behavior,
among other disorders (Frecksa et al., 2016).
Conclusion
In conclusion, both the currently available scientific evidence on the acute and long-term effects of
ayahuasca and the studies that employed it as a therapeutic tool with psychiatric populations
suggest that ayahuasca is a substance with an acceptable physiological and psychological safety
profile and with therapeutic potential (McKenna, 2004; Gable, 2007; Bouso & Riba, 2011; Barbosa
et al., 2012; dos Santos, 2013).
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Date: August 17, 2017
Signed by:
!
Charles S. Grob, M.D.
Harbor-UCLA Medical Center, California, USA

Dartiu Xavier da Silveira, M.D.
Universidad Federal de São Paulo, Brazil
Dennis Jon McKenna, Ph.D.
Center for Spirituality and Healing, University of Minnesota, USA

Draulio Barros de Araujo, Ph.D.
Brain Institute UFRN, Brazil

Jordi Riba, Ph.D.
Experimental Neuropsychopharmacology Research Group, Sant Pau Hospital, Spain

José Carlos Bouso, Ph.D.
International Center for Ethnobotanical Education, Research & Service (ICEERS), Spain

Paulo Cesar Ribeiro Barbosa, Ph.D.
Universidade Estadual de Santa Cruz, Brazil
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!
Rafael Guimarães dos Santos, Ph.D.
Departamento de Neurociências e Comportamento, Escola de Medicina de Ribeirão Preto, Universidade de
São Paulo, Brazil
"
Constanza Sánchez Aviléz, Ph.D.
International Center for Ethnobotanical Education, Research & Service, Spain
"
Beatriz Caiuby Labate, Ph.D.
Center for Research and Post Graduate Studies in Social Anthropology, Mexico $
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