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Calculated LD50 values, for A) compounds with limited solubility B) soluble compounds.
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The acute toxicities of 19 chemicals were assessed using G. mellonella larvae. The results obtained were compared against LD50 values derived from in vitro cytotoxicity tests and against in vivo acute oral LD50 values. In general, cell culture systems overestimated the toxicity of chemicals, especially low toxicity chemicals. In contrast, toxicity...
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... chemicals selected for testing (5-aminosalicylic acid, propylparaben and xylene) could not be solubilised and could therefore not be injected. The toxicity of 8 chemicals could only be estimated due to limited solubility (Table 1A). A dilution series of the remaining 19 chemicals was made to provide concentrations bracketing the expected LD50 dose. ...Context 2
... dilution series of the remaining 19 chemicals was made to provide concentrations bracketing the expected LD50 dose. Each dilution was injected into a group of G. mellonella larvae, mortality recorded and the LD50 values calculated (Table 1B). ...Context 3
... next considered toxicities according to the GHS categorisation of chemicals. This system places chemicals into one of five categories (Fig. 1a and Table S1) ranging from low toxicity (GHS category 5, LD50 2000e5000 mg kg-1) to highly toxic (GHS category 1, LD50 < 5 mg kg-1). For the 9 chemicals tested which had been assigned to GHS category 5, the toxicity measured in G. mellonella larvae was consistent with the GHS categorisation (Fig. 1b). ...Similar publications
Kin discrimination is often beneficial for group-living animals as it aids in inbreeding avoidance and providing nepotistic help. In mammals, the use of olfactory cues in kin discrimination is widespread and may occur through learning the scents of individuals that are likely to be relatives, or by assessing genetic relatedness directly through ass...
Peromyscus bullatus and Peromyscus difficilis are sympatric and phenotypically similar rodents. Because of this, misidentification of both species is frequent in the field and in mammal collections. In this study, P. bullatus specimens were retrieved from the P. difficilis specimens, in the mammal collection of the Instituto de Investigaciones Biol...
Citations
... They are a suitable size for manipulation, reduced biological risk, as well as low rearing costs. The use of larvae has been an excellent alternative for in vivo toxicological tests in an in vivo model to study the immune response to pathogens, antibiotics, and drugs, the toxicity of compounds, and food preservatives (Allegra et al. 2018;Dolan et al. 2016;Megaw et al. 2015;Moya-Andérico et al. 2021;Vellé et al. 2017). In a study using eight food preservatives, there was a positive correlation in the LD 50 values in the G. mellonella larvae model and in mammalian models. ...
Purple yam (Dioscorea trifida) has high agricultural productivity in the Amazon region but has not been much investigated. Multivariate strategies were employed to optimize the method to obtain a food extract rich in functional compounds. The optimal conditions showed that the combination of 0.2 g of dried purple yam with 15 mL of citric acid (1%) under agitation in a water bath at 36 °C for 4 min yields an extract with a high content of peonidin-3-O-glucoside-5-O-glucoside, peonidin-3-O-feruloylglycosideum-5-O-glycosideum, peonidin-3-Op-coumaroylglycosideum-5-O-glycoside, quinic acid, apigenin 8-C-xyloside-6-C-glycoside (vicenin 3), quinic acid, apigenin 6-C-xyloside-8-C-glycoside (vicenin 1), and isorhamnetin-O-dihexoside. Our extract also presented 56.91 ± 0.76 mg 100 g⁻¹ of total anthocyanins, 417.05 ± 11.37 mg 100 g⁻¹ total carotenoids, and 493.09 ± 6.38 mg GAE 100 g⁻¹ of total phenolic compounds. In a Galleria mellonella, in vivo model consumption safety was for up to 150 g by 70 kg of body weight. In addition, it inhibited the growth of Gram-negative bacteria (Salmonella typhimurium and Escherichia coli). The simple, fast, and ecofriendly extraction conditions, combined with the biological effects of our extract, gives us a great potential for its application in food or packaging technologies.
... (E)-trans-2-nonenal previously showed low cytotoxicity towards a MRC-5 cell line [38], and its LD 50 was 138 mg/mL when tested in an in vivo toxicity Galleria mellonella larvae model, corresponding to 6.896 g (E)-trans-2-nonenal per Kg of larvae (Fig. 4). G. mellonella larvae have been widely used to evaluate the toxicity of antimicrobial compounds, exhibit a strong correlation with mammalian immune systems, and the toxicity tests conducted using them correlate effectively with mammalian models [46][47][48][49][50][51]. For these overall reasons, we next focused on further exploring the (E)-trans-2-nonenal antimicrobial potential. ...
... Three ways of inoculation (injection, oral, and topical) could be used in G. mellonella [15]. Since the larval integument is composed by the cuticula, an external physical barrier, that is analogous, in function, to the stratum corneum of the skin, and an epidermal cell monolayer equivalent to the keratinocyte layer in the mammalian epidermis [16], this model may be suitable as a superficial infection model. ...
Introduction. Malassezia globosa is a yeast species that belongs to the mycobiota of humans and animals, associated with dermatological disorders, such as dandruff. This is a chronic scalp skin disorder characterized by flaking and itching. Treatments include commercial shampoo with different formulations that contain antifungal activities like zinc pyrithione (ZPT) or piroctone olamine (PO). The effectiveness of these formulations has been evaluated for decades for dandruff symptom relief of volunteers. To date, non-mammalian, in vivo methods exist to test formulations of these actives.
Aim. To evaluate in vivo in Galleria mellonella larva, two commercial antifungal shampoos (shampoo with 1 % ZPT and 1.6 % zinc Carbonate and shampoo with 0.5 % PO) against this species.
Methodology. G. mellonella larvae were inoculated with M. globosa on abraded cuticular surface. Then, integument cell viability, histological changes, and fungal burden were evaluated.
Results. Larvae inoculated with M. globosa showed higher lesion melanization and tissue damage. In addition, M. globosa population showed to increase over time. Concerning the shampoo’s effectiveness, both formulations significantly reduced M. globosa burden and tissue damage.
Conclusion. G. mellonella larvae were allowed to evaluate M. globosa superficial infection and antifungal effectiveness. Shampoos with ZPT and PO showed a positive effect on inoculated larvae.
... G. mellonella allows for the evaluation of the systemic toxicity of compounds due to some physiological similarities with mammalians [38,39]. In addition, G. mellonella is an invertebrate model that is more accepted by ethical committees than mice models. ...
Drug-resistant bacteria constitute a big barrier against current pharmacotherapy. Efforts are urgent to discover antibacterial drugs with novel chemical and biological features. Our work aimed at the synthesis, evaluation of antibacterial effects, and toxicity of licochalcone C (LCC), a naturally occurring chalcone. The synthetic route included six steps, affording a 10% overall yield. LCC showed effects against Gram-positive bacteria (MIC = 6.2–50.0 µg/mL), Mycobacterium species (MIC = 36.2–125 µg/mL), and Helicobacter pylori (MIC = 25 µg/mL). LCC inhibited the biofilm formation of MSSA and MRSA, demonstrating MBIC50 values of 6.25 μg/mL for both strains. The investigations by fluorescence microscopy, using PI and SYTO9 as fluorophores, indicated that LCC was able to disrupt the S. aureus membrane, similarly to nisin. Systemic toxicity assays using Galleria mellonella larvae showed that LCC was not lethal at 100 µg/mL after 80 h treatment. These data suggest new uses for LCC as a compound with potential applications in antibacterial drug discovery and medical device coating.
... To investigate the potential toxicity of the active compounds, we employed Galleria mellonella larvae as an in vivo model, following the methodology suggested by Allegra et al. [13]. The larvae were reared in our laboratory using standardized protocols established by our research team [14]. ...
Methicillin-resistant Staphylococcus aureus (MRSA) is widely recognized as a causative agent for various infections acquired in healthcare settings as well as in the community. Given the limited availability of effective antimicrobial agents to combat MRSA infections, there is an increasing need to explore alternative therapeutic strategies. This study aimed to assess the antimicrobial, anti-adhesive, anti-biofilm properties, and toxicity of 175 newly synthesized compounds, belonging to seven different classes, against MRSA. Initially, the compounds underwent screening for antimicrobial activity using the agar diffusion method. Subsequently, active compounds underwent further evaluation to determine their minimum inhibitory concentrations through microdilution. Anti-biofilm and anti-adhesive properties were assessed using the crystal violet method, while toxicity was tested using the alternative infection model Galleria mellonella. Among the tested compounds, two xanthenodiones exhibited the most promising activities, displaying bactericidal effects along with anti-adhesive and anti-biofilm properties. Moreover, the observed non-toxicity in G. mellonella larvae suggests that these compounds hold significant potential as alternative therapeutic options to address the escalating challenge of MRSA resistance in both hospital and community settings.
... The experiment used larvae of the G. mellonella species, as described by Allegra et al. and Marena et al. with modifications [54,58]. A minimum of ten larvae per group (n = 10) were used, which were fed and raised at 25 °C until they weighed more than 0.2 mg. ...
Plant-based insecticides offer advantages such as negligible residual effects, reduced risks to both humans and the environment, and immunity to resistance issues that plague conventional chemicals. However, the practical use of monoterpenes in insect control has been hampered by challenges including their poor solubility and stability in aqueous environments. In recent years, the application of nanotechnology-based formulations, specifically nanoemulsions, has emerged as a prospective strategy to surmount these obstacles. In this study, we developed and characterized nanoemulsions based on cymene and myrcene and assessed their toxicity both in vitro using human keratinocytes (HaCAT) cells and in an in vivo model involving Galleria mellonella larvae. Additionally, we investigated the insecticidal efficacy of monoterpenes against the mosquito Aedes aegypti, the primary dengue vector, via larval bioassay. Employing a low-energy approach, we successfully generated nanoemulsions. The cymene-based nanoemulsion exhibited a hydrodynamic diameter of approximately 98 nm and a zeta potential of −25 mV. The myrcene-based nanoemulsion displayed a hydrodynamic diameter of 118 nm and a zeta potential of −20 mV. Notably, both nanoemulsions demonstrated stability over Beilstein J. Nanotechnol. 2024, 15, 104-114. 105 60 days, accompanied by controlled release properties and low toxicity towards HaCAT cells and Galleria mellonella larvae. Moreover , the nanoemulsions exhibited significant lethality against third-instar Aedes aegypti larvae at a concentration of 50 mg/L. In conclusion, the utilization of nanoemulsions encapsulating cymene and myrcene presents a promising avenue for overcoming the limitations associated with poor solubility and stability of monoterpenes. This study sheds light on the potential of the nanoemul-sions as effective and environmentally friendly insecticides in the ongoing battle against mosquito-borne diseases.
... An in vivo toxicity assay using Galleria mellonella was then carried out to evaluate the toxicity of 5g in a nonanimal infection model. 40,41 Ten wax moth larvae were injected with 5g at concentrations of 50 mg/kg, 20 mg/kg, and 10 mg/kg (Table S5, Supporting Information). By the end point of the assay at 120 h, 10 of 10 larvae were still alive at all doses. ...
A new class of amphiphilic molecules, the lipoguanidines, designed as hybrids of guanidine and fatty acid compounds, has been synthesized and developed. The new molecules present both a guanidine polar head and a lipophilic tail that allow them to disrupt bacterial membranes and to sensitize Gram-negative bacteria to the action of the narrow-spectrum antibiotics rifampicin and novobiocin. The lipoguanidine 5g sensitizes Klebsiella pneumonia, Acinetobacter baumannii, Pseudomonas aeruginosa, and Escherichia coli to rifampicin, thereby reducing the antibiotic minimum inhibitory concentrations (MIC) up to 256-fold. Similarly, 5g is able to potentiate novobiocin up to 64-fold, thereby showing a broad spectrum of antibiotic potentiating activity. Toxicity and mechanism studies revealed the potential of 5g to work synergistically with rifampicin through the disruption of bacterial membranes without affecting eukaryotic cells.
... Although in this work some toxicity alerts were predicted for the pyridylamino-Nacetyl and N-phenyl substituted pyrazolines, the most active pyrazolines showed low toxicity risk when compared to the predicted for the previously reported N-acetyl and N-phenyl substituted styryl pyrazolines (Ekawati et al. 2022). In our study, toxicity was validated in vivo using G. mellonella, and this model has shown strong data correlation when compared to mammalian models and provides a more accurate representation of in vivo toxicity than in vitro cell-based assays (Allegra et al. 2018;Piatek et al. 2021). ...
The development of new antimalarials is paramount to keep the goals on reduction of malaria cases in endemic regions. The search for quality hits has been challenging as many inhibitory molecules may not progress to the next development stage. The aim of this work was to screen an in-house library of heterocyclic compounds (HCUV) for antimalarial activity combining computational predictions and phenotypic techniques to find quality hits. The physicochemical determinants, pharmacokinetic properties (ADME), and drug-likeness of HCUV were evaluated in silico, and compounds were selected for structure-based virtual screening and in vitro analysis. Seven Plasmodium target proteins were selected from the DrugBank Database, and ligands and receptors were processed using UCSF Chimera and Open Babel before being subjected to docking using Autodock Vina and Autodock 4. Growth inhibition of P. falciparum (3D7) cultures was tested by SYBR Green assays, and toxicity was assessed using hemolytic activity tests and the Galleria mellonella in vivo model. From a total of 792 compounds, 341 with good ADME properties, drug-likeness, and no interference structures were subjected to in vitro analysis. Eight compounds showed IC50 ranging from 0.175 to 0.990 µM, and active compounds included pyridyl-diaminopyrimido-diazepines, pyridyl-N-acetyl- and pyridyl-N-phenyl-pyrazoline derivatives. The most potent compound (UV802, IC50 0.178 µM) showed no toxicophoric and was predicted to interact with P. falciparum 1-cysperoxidredoxin (PfPrx1). For the remaining 7 hits (IC50 < 1 μM), 3 showed in silico binding to PfPrx1, one was predicted to bind the haloacid dehalogenase-like hydrolase and plasmepsin II, and one interacted with the plasmodial heat shock protein 90.
Supplementary Information
The online version contains supplementary material available at 10.1007/s00436-023-08089-7.
... Wax moth Galleria mellonella L. is one of the most commonly used models for toxicological investigations [21][22][23][24], including analysis of the antibacterial action of drugs [25] and in vivo assessment of pathogenicity of various microorganisms [26][27][28]. Wax moth larvae develop toxicosis in the midgut, which is accompanied by changes in the microbiota, digestion activity, and defense systems [11,12]. ...
Simple Summary
The insect gut microbiota plays a crucial role in the host’s resistance to pathogenic microorganisms and toxins. Resident microorganisms may persist for a long time and maintain a certain location due to the synthesis of antimicrobial agents (including antibiotics). We consider it one of the adaptation mechanisms of microorganisms in various communities. Not only do the uncontrolled use of antibiotics and changes in environmental conditions drastically alter the microbiota structure and give rise to resistant microorganisms, but they also cause a number of alterations in the host’s physiology and its sensitivity to pathogens. This study opens up new prospects for further research into antibiotic-resistant symbiotic microorganisms, their benefits for persistence in the dynamic environment of the insect’s gut, and the conditions necessary for changing their strategy and manifestation of virulent properties.
Abstract
Environmental pollution with antibiotics can cause antibiotic resistance in microorganisms, including the intestinal microbiota of various insects. The effects of low-dose aminoglycoside antibiotic (amikacin) on the resident gut microbiota of Galleria mellonella, its digestion, its physiological parameters, and the resistance of this species to bacteria Bacillus thuringiensis were investigated. Here, 16S rDNA analysis revealed that the number of non-dominant Enterococcus mundtii bacteria in the eighteenth generation of the wax moth treated with amikacin was increased 73 fold compared to E. faecalis, the dominant bacteria in the native line of the wax moth. These changes were accompanied by increased activity of acidic protease and glutathione-S-transferase in the midgut tissues of larvae. Ultra-thin section electron microscopy detected no changes in the structure of the midgut tissues. In addition, reduced pupa weight and resistance of larvae to B. thuringiensis were observed in the eighteenth generation of the wax moth reared on a diet with amikacin. We suggest that long-term cultivation of wax moth larvae on an artificial diet with an antibiotic leads to its adaptation due to changes in both the gut microbiota community and the physiological state of the insect organism.
... In particular, Gm appears to be a very promising model to investigate the antimicrobial efficacy and toxicity of various drugs [30,31]. Recently, Allegra et al. reported evidence that larvae can be a good model for assessing the toxicity of drugs, showing that the Lepidoptera provided a reliable LD 50 assessment of acute chemical toxicity [32]. Furthermore, Gm larvae have several advantages, such as low cost, easy maintenance, and manipulation, as well as not being subjected to legal and ethical restrictions that hinder the use of vertebrates (Directive n. 2010/63/UE; https://eur-lex.europa.eu/eli/dir/2010/63/ ...
Photodynamic therapy (PDT) is an anticancer/antibacterial strategy in which photosensitizers (PSs), light, and molecular oxygen generate reactive oxygen species and induce cell death. PDT presents greater selectivity towards tumor cells than conventional chemotherapy; however, PSs have limitations that have prompted the search for new molecules featuring more favorable chemical–physical characteristics. Curcumin and its derivatives have been used in PDT. However, low water solubility, rapid metabolism, interference with other drugs, and low stability limit curcumin use. Chemical modifications have been proposed to improve curcumin activity, and metal-based PSs, especially ruthenium(II) complexes, have attracted considerable attention. This study aimed to characterize six Ru(II)-arene curcuminoids for anticancer and/or antibacterial PDT. The hydrophilicity, photodegradation rates, and singlet oxygen generation of the compounds were evaluated. The photodynamic effects on human colorectal cancer cell lines were also assessed, along with the ability of the compounds to induce ROS production, apoptotic, necrotic, and/or autophagic cell death. Overall, our encouraging results indicate that the Ru(II)-arene curcuminoid derivatives are worthy of further investigation and could represent an interesting option for cancer PDT. Additionally, the lack of significant in vivo toxicity on the larvae of Galleria mellonella is an important finding. Finally, the photoantimicrobial activity of HCurc I against Gram-positive bacteria is indeed promising.
