Activity Of Snake Venoms Research Articles

An alternative method for comparing hemorrhagic activity of snake venoms following one of the 3R's principles

Venom-induced hemorrhage analysis usually is performed by Minimum Hemorrhagic Dose (MHD), however a similar method can be used to compare venoms with fewer laboratory animals. Our work compared the MHD of five different venoms, with the size of hemorrhagic spot, finding good correlations in the results. Considering the 3Rs principle, we propose the use of the hemorrhagic spot method to compare hemorrhagic activity of snake venoms, rather than using the MHD method, since the first one needs 5 times less animals than the other.

Bloody insights: using organ-on-chip technology to study haemorrhagic activities of snake venoms on endothelial tubes

Bloody insights: using organ-on-chip technology to study haemorrhagic activities of snake venoms on endothelial tubes

Anticoagulant activity in Australasian elapid snake venoms and neutralisation with antivenom and varespladib

The venoms of Australasian elapid snakes are known to possess coagulant activity, including some with strong procoagulant activity and others with anticoagulant activity, although the latter are less well known. This study investigates the anticoagulant activity of Australasian elapid snake venoms, and whether this activity is neutralised by commercial snake antivenom and varespladib (PLA2 inhibiting agent). Clotting assays were completed for 34 species of Australasian elapids. Antivenom neutralisation assays with tiger snake antivenom (TSAV) were performed on five species to determine if there was cross-neutralisation. Varespladib neutralisation assays were also completed for the same five species. All Pseudechis species venoms had anticoagulant activity, except P. porphyriacus, which was procoagulant. Pseudechis species venoms had similar anticoagulant potency ranging from the most potent P. colletti venom to the least potent P. butleri venom. The three Austrelaps (copperhead) species venoms were the next most potent anticoagulants. Six further snakes, Elapognathus coronatus, Acanthophis pyrrhus, A. antarcticus, Suta suta, Denisonia devisi and D. maculata, had weaker anticoagulant activity, except for D. maculata which had similar anticoagulant activity to Pseudechis species. Tiger Snake Antivenom (1200mU/mL) neutralised the anticoagulant effect of P. australis for concentrations up to 1 mg/mL. TSAV (1200mU/mL) also neutralised P. colletti, D. maculata, A. superbus and A. pyrrhus venoms at their EC50, demonstrating cross neutralisation. Varespladib neutralised the anticoagulant effect of P. australis venom at 5 μM and for venoms of P. colletti, D. maculata, A. superbus and A. pyrrhus. We found anticoagulant activity to be present in six genera of Australasian snakes at low concentrations, which can be completely neutralised by both antivenom and varespladib. Anticoagulant activity in Australian elapid venoms was associated with species possessing high PLA2 activity without procoagulant snake venom serine proteases.

Using organ-on-a-chip technology to study haemorrhagic activities of snake venoms on endothelial tubules

Snakebite envenomation is a major public health issue which causes severe morbidity and mortality, affecting millions of people annually. Of a diverse range of clinical manifestations, local and systemic haemorrhage are of particular relevance, as this may result in ischemia, organ failure and even cardiovascular shock. Thus far, in vitro studies have failed to recapitulate the haemorrhagic effects observed in vivo. Here, we present an organ-on-a-chip approach to investigate the effects of four different snake venoms on a perfused microfluidic blood vessel model. We assess the effect of the venoms of four snake species on epithelial barrier function, cell viability, and contraction/delamination. Our findings reveal two different mechanisms by which the microvasculature is being affected, either by disruption of the endothelial cell membrane or by delamination of the endothelial cell monolayer from its matrix. The use of our blood vessel model may shed light on the key mechanisms by which tissue-damaging venoms exert their effects on the capillary vessels, which could be helpful for the development of effective treatments against snakebites.

Development of a high-throughput in vitro screening method for the assessment of cell-damaging activities of snake venoms.

Snakebite envenoming is a globally important public health issue that has devastating consequences on human health and well-being, with annual mortality rates between 81,000 and 138,000. Snake venoms may cause different pathological effects by altering normal physiological processes such as nervous transfer and blood coagulation. In addition, snake venoms can cause severe (local) tissue damage that may result in life-long morbidities, with current estimates pointing towards an additional 450,000 individuals that suffer from permanent disabilities such as amputations, contractions and blindness. Despite such high morbidity rates, research to date has been mainly focusing on neurotoxic and haemotoxic effects of snake venoms and considerably less on venom-induced tissue damage. The molecular mechanisms underlaying this pathology include membrane disruption and extracellular matrix degradation. This research describes methods used to study the (molecular) mechanisms underlaying venom-induced cell- and tissue damage. A selection of cellular bioassays and fluorescent microscopy were used to study cell-damaging activities of snake venoms in multi-well plates, using both crude and fractionated venoms. A panel of 10 representative medically relevant snake species was used, which cover a large part of the geographical regions most heavily affected by snakebite. The study comprises both morphological data as well as quantitative data on cell metabolism and viability, which were measured over time. Based on this data, a distinction could be made in the ways by which viper and elapid venoms exert their effects on cells. We further made an effort to characterise the bioactive compounds causing these effects, using a combination of liquid chromatography methods followed by bioassaying and protein identification using proteomics. The outcomes of this study might prove valuable for better understanding venom-induced cell- and tissue-damaging pathologies and could be used in the process of developing and improving snakebite treatments.

Inhibition of phospholipase A2 from Naja haje and Naja nigricollis venoms by active fraction of Moringa oleifera leaves: in vitro and in silico methods

Phospholipases are one of the principal toxic enzymes in snake venoms inducing a wide variety of pharmacological effects after envenomation. Natural inhibitors from plants are known to inhibit the toxic enzyme activities of snake venoms. In this study, ethanol crude extract of M. oleifera leaves was partitioned using n-hexane and ethyl acetate after which fractionation was done using column and thin layer chromatography. Subsequently, the inhibitory activities of the crude extract and sub-fractions of M. oleifera were investigated against phospholipases A2 isolated from Naja haje and Naja nigricollis venoms using in vitro and in-silico approaches while EchiTab-PLUS polyvalent antivenom was used as the standard drug. The molecular weight of isolated N. haje phospholipase A2 (NH-PL) and N. nigricollis phospholipase A2 (NN-PL) were 24.11 and 35.22 kDa respectively. NH-PL enzyme had a specific activity of 2.70 μM/min/mg substrate while NN-PL activity was 2.10 μM/min/mg substrate. The Km of NH-PL was 0.330 μM with Vmax of 0.085 μM/mL min while NN-PL had Vmax of 0.198 μM/mL.min and Km of 0.670 μM. M. oleifera n-hexane sub-fraction 5 (MOLH5) exhibited a total inhibition of NN-PL and NH-PL enzyme activities at all concentrations used. Molecular docking of the phytoconstituents of MOLH5 against the catalytic site of phospholipase A2 revealed 2-Hydrazino-8-hydroxy-4-phenylquinoline as the lead compound and a potential drug candidate with a docking score of −6.789 kcal/mol. Findings indicated that MOLH5 possesses phospholipase A2 natural inhibitors that could be explored as a therapy for snake envenoming.

Musa spp. cultivars as a neutralising source against some toxic activities of Bothrops and Crotalus genus snake venoms

Accidents involving snakes from Bothrops spp. and Crotalus spp. constitute the most important cause of envenomation in Brazil and Argentina. Musa spp. (banana) have been reported to be used in popular medicine against snakebite by the members of the Canudos Settlement, located in Goiás. In this way, the aim of this work was to evaluate the antivenom effect of the Ouro (AA), Prata (AAB), Prata-anã (AAB) and Figo (ABB) cultivars against in vitro (phospholipase, coagulation and proteolytic) and in vivo (lethality and toxicity) activities caused by the venoms and toxicity (Artemia salina nauplii and Danio rerio embryos) of Musa spp. as well as the annotation of chemical compounds possibly related to these activities. From the in vitro antiophidic tests with the sap, we observed 100% inhibition of the phospholipase and coagulant activities with the cultivars Prata-anã and Figo against the venoms of B. alternatus and C. d. collineatus, B. diporus and B. pauloensis, respectively, and neutralisation of the lethality against the B. diporus venom. It was observed that the cultivars of Musa spp. did not show toxicity against Artemia salina nauplii and Danio rerio embryos. The sap analysis via HPLC-MS/MS allowed the annotation of the 13 compounds: abscisic acid, shikimic acid, citric acid, quinic acid, afzelechin, Glp-hexose, glucose, sucrose, isorhamnetin-3-O-galactoside-6-raminoside, kaempferol-3-glucoside-3-raminoside, myricetin-3-O-rutinoside, procyanidin B1 and rutin. Therefore, it can be seen that Musa spp. is a potential therapeutic agent that can act to neutralise the effects caused by snakebites.

Proteomic and functional analyses of Lachesis acrochorda snake venom from the Valle del Cauca Department of Colombia

Lachesis acrochorda envenomation has a lethality rate of approximately 90%. Despite its high lethality, little is known about its local and systemic effects and its relationship with its protein content. Thus, to increase knowledge of L. acrochorda snake venom from the Southwestern ecoregion of Colombia, we developed a proteomic analysis using a "bottom-up shotgun proteomic profiling" approach. Besides, we evaluated toxinological properties and compared the effects with the Bothrops asper snake venom activities. The RP-HPLC profile showed similarities with the L. acrochorda snake venom from the Northwestern ecoregion of Colombia. However, the results displayed differences in the protein families identified, probably due to the proteomic identification strategy. The in vitro and in vivo tests showed a L. acrochorda snake venom with Phospholipase A2 and metalloproteinase activities related to myotoxic, edematic, and hemorrhagic effects. Nevertheless, the L. acrochorda snake venom displayed a low lethality despite a large amount of inoculated venom. This investigation's results will help us improve the knowledge about the relationship between the clinical manifestations of L. acrochorda envenomation and the venom protein content.

Toxicity study of Gloydius brevicaudus venom on Hela and Hep G2 cells

The purpose of this study was to explore the cytotoxicity of Gloydius brevicauda venom on tumor cells. Hela and Hep G2 cells were used as the research subjects. The MTT assay was employed to investigate the proliferative activity of snake venom on tumor cells. The cell scratch assay was conducted to study the migration ability of tumor cells treated with snake venom. The Hoechst 33258 fluorescent staining method was utilized to examine the damage caused by snake venom on tumor cells. The results demonstrated that the half maximal inhibitory concentration (IC50) of the venom on Hela and Hep G2 cells at 48 hours was 8.176 µg/ml and 12.276 µg/ml, respectively. Furthermore, at a concentration of 4 µg/ml, the venom was able to inhibit the migration of tumor cells. Cell nuclear fluorescence staining revealed that the venom at concentrations of 8 µg/ml and 12 µg/ml induced DNA condensation in Hela and Hep G2 cells, respectively. In conclusion, the venom of Gloydius brevicauda was found to inhibit cell proliferation and migration, as well as induce cell apoptosis.

Differences between Two Groups of Burmese Vipers (Viperidae: Azemiops) in the Proteomic Profiles, Immunoreactivity and Biochemical Functions of Their Venoms.

Two recently revised Azemiops snakes with apparent differences in their external appearances and skeletal morphologies but unclear genetic boundaries have been proposed. Some researchers have refrained from using the newly proposed taxonomy because these two “species” might be two clades corresponding to different geographical populations of Azemiops feae. To improve the understanding of the kinship of these two Burmese viper groups, more of their characteristics should be explored in depth. We performed a comparative analysis of the proteomic profiles and biochemical activities of snake venoms from these two groups (Sichuan A. feae and Zhejiang A. feae) and evaluated the immunorecognition capacity of commercial antivenoms toward them. Eight protein families were identified in venoms from these two groups, while phospholipase B was only detected in venom from Sichuan A. feae. These protein families displayed varying degrees of differences in relative abundance between venoms, and phospholipase A2 (Sichuan A. feae: 57.15%; Zhejiang A. feae: 65.94%) was the predominated component. Gloydius brevicaudus antivenom exhibited the strongest capacity to immunologically recognize these two venoms, but this was mainly limited to components with high molecular masses, some of which differed between venoms. Additionally, Zhejiang A. feae venom was more toxic than Sichuan A. feae venom, and the venoms expressed remarkable differences in enzymatic activities, probably resulting from the variation in the relative abundance of specific protein families. Our findings unveil differences between the two Burmese viper groups in terms of proteomic profiles, immunoreactivity, and the biochemical functions of their venoms. This information will facilitate the management of snakebites caused by these snakes.

The relative efficacy of chemically diverse small-molecule enzyme-inhibitors against anticoagulant activities of Black Snake (Pseudechis spp.) venoms

Snakebite remains a worldwide public health burden and a severely neglected tropical disease. Recent research has begun to focus on the potential use of repurposed small-molecule enzyme-inhibitors as early treatments to neutralise the effects of snake venoms. Black snakes (Pseudechis spp.) are a widespread and dangerously venomous group found throughout Australia and New Guinea. Utilising validated coagulation assays, our study assessed the efficacy of two chemically different small molecule inhibitors, a phospholipase A2 inhibitor (varespladib) and a metalloproteinase inhibitor (prinomastat), in vitro neutralisation of the anticoagulant prothrombinase-inhibiting activity of venom from seven species within the Pseudechis genus (P. australis, P. butleri, P. coletti, P. guttatus, P. papuanus, P.rossignolii, P. sp (NT).). Varespladib was shown to be highly effective at neutralising this anticoagulant activity for all seven species, but with P. coletti notably less so than the others. In contrast, prinomastat showed strong neutralisation for five out of the seven species, but was ineffective at neutralising the activity of P. coletti or P. rossignolii venoms. This suggests that varespladib binds to a highly conserved site but that prinomastat binds to a more variable site. These results build upon recent literature indicating that metalloproteinase inhibitors have cross-neutralising potential towards snake venom phospholipase A2 toxins, but with higher degrees of variability that PLA2-specific inhibitors. An important caveat is that these are in vitro tests and while suggestive of potential clinical utility, in vivo animal testing and clinical trials are required as future work.

Untangling interactions between Bitis vipers and their prey using coagulotoxicity against diverse vertebrate plasmas

Venom is a key evolutionary innovation which plays a primary role in prey subjugation by venomous snakes. However, while there is a growing body of literature indicating the composition and activity of snake venoms is under strong natural selection driven by differences in prey physiology, the majority of studies have historically focussed on the activity of snake venoms with regards only towards human or mammalian physiologies. This study aimed to use clotting assays measuring both time and strength of clotting to characterise the coagulotoxic activity of venoms from a taxonomically, morphologically, and ecologically diverse range of Bitis spp. of viperid snakes upon the plasma of model species: amphibian (Cane Toad, Rhinella marina); lizard (Blue-tongue Skink, Tiliqua scincoides); avian (Domestic Chicken, Gallus gallus); and rodent (Brown Rat, Rattus norvegicus). Significant variation in coagulotoxic activity across the different plasmas was observed between species and compared to the known affects upon human plasma. Bitis caudalis was notable in being active on all four plasmas, but in extremely divergent manners: accelerating clotting times and producing strong, stable clots upon amphibian plasma (consistent with true procoagulation); accelerating clotting time but producing weak, unstable clots upon lizard plasma (consistent with pseudo-procoagulation); delaying avian clotting time beyond machine maximum reading time (strong anticoagulation consistent with either inhibition of clotting enzymes or total destruction of fibrinogen, or both); and delaying clotting of rodent plasma (consistent with inhibition of clotting enzymes) and with only weak clots formed (consistent with destruction of fibrinogen). In contrast, the sister species B. peringueyi and B. schneideri displayed activity only upon the lizard plasma, slightly accelerating the clotting times to produce weak, unstable clots (consistent with pseudo-procoagulation). The other dwarf species, B. cornuta, displayed strong anticoagulation upon avian and rodent plasmas, delaying clotting beyond the machine maximum reading time (strong anticoagulation consistent with either inhibition of clotting enzymes or total destruction of fibrinogen, or both). In contrast, the giant species studied (B. gabonica) showed only a very weak pseudo-procoagulant activity upon lizard plasma. The wide range of variation seen within this study highlights the importance of studying venom activity on relevant models when making conclusions about the ecological role of venoms and the extreme limitation in extrapolating animal results to predict potential human clinical effects.

Characterization and Evaluation of the Effects of Indigofera pulchra, Aristolochia albida and Andrographis paniculata Leaves Extract Phenolics against the Activity of Naja nigricollis and Echis ocellatus Snake Venoms

With the increased incidence of snake envenomation, high cost of venom antiserum; its adverse side effects and lack of storage facilities for antiserum especially in rural areas, the use of plants as alternatives for treatment of poisonous snakebites is important, especially in remote areas. This research was aimed at characterization and evaluation of the effects of Indigofera pulchra, Aristolochia albida and Andrographis paniculata leaves extract phenolics against the activity of Naja nigricollis and Echis ocellatus snake venoms. The plants samples were extracted using chloroform, after which a qualitative and quantitative phytochemical analysis was done, followed by characterization analyses (GC-MS and FTIR). Preperatory and analytical tin layer chromatography analyses was carried out on all the extracts, flavonoids and tannins fractions were isolated, using garlic and tannic acids as standards. In-vitro inhibition analyses of the partially purified phenolics was done to ascertain the effects to the isolated phenolic fractions against the two selected crude snake venoms. The plant extracts characterization done revealed that all the three extracts contain phenolics and specifically important compounds like, Benzaldehyde-2-hydro-4-methoxy, rutin and gallocatechin, all which has been reported to have anti-snake venom capability. The inhibition studies carried out revealed that the flavonoid fractions of the extracts has a higher inhibitory effect against the snake venoms than the tannin fractions of all the extracts. Characterization and evaluation studies, done in this research has revealed that these plants’ phenolic fractions have effects on the two snake venoms and can help in the management and treatment of snake bite.

Ethnomedicinal plants and isolated compounds against Snake venom activity: A review

Snakebite is an occupational hazard that has affected the population in tropical and subtropical countries. Worldwide approximately 5.4 million bites, 2.7 million envenomations, and 81,000-1,38,000 deaths are observed per annum. The incidences are higher among farmers and plantation workers. Antivenom is the only treatment available and the production of the same is challenging due to geographical variation of snakes, storage conditions, and non-availability of venom for production. Antivenom therapy is associated with immediate or delayed hypersensitivity and does not prevent local tissue damage. Thus the search for medicinal plants by the scientific community has become relevant. The ethnobotanical studies on various plants have revealed their use to treat various ailments including snakebite. Hence, the review is aimed to amass the medicinal plants studied and also emphasize various components isolated that have shown promising results.

Synthesis, characterization and utilization of a new series of 1,2,3-triazole derivatives to neutralize some toxic activities of Bothrops jararaca snake venom

Snake envenomation is a public health problem, and while serum therapy prevents death, the local effects of venoms can lead to amputations or morbidities. Thus, alternative treatments deserve attention. In this study, we tested eight derivatives of 1,2,3-triazole against some toxic activities of Bothrops jararaca venom. The derivatives were synthesized, and their structures analyzed by infrared and nuclear magnetic resonance. After that, the ability of compounds to inhibit hemolysis, coagulation, proteolysis, hemorrhaging, edema, and lethal activities of B. jararaca venom was investigated. The derivatives were incubated with B. jararaca venom (incubation protocol), administered before (prevention protocol) or after (treatment protocol) injecting venom into the mice. Then, hemorrhaging assay occurred. As a result, most of the derivatives inhibited the activities, even if they were incubated, injected before or after B. jararaca venom. However, the derivatives TRI 07 and TRI 18 seemed to be the most efficient in impairing hemorrhaging. The derivatives showed a low drug score of toxicity based on an in silico technique. Therefore, the derivatives fulfilled physicochemical and biological requirements to become drugs, and they may be a brand new initiative for designing antivenom molecules to complement antivenom therapy to efficiently block tissue necrosis or any other local effects.

L-amino acid oxidase from snake venom: Biotransformation and induction of apoptosis in human colon cancer cells

This study evaluated the potential of antitumor activity of snake venom from Vipera ammodytes and L-amino acid oxidase from Crotalus adamanteus on different colorectal cancer cell lines through determination of cytotoxic activity by MTT assay, pro-apoptotic activity by acridine orange/ethidium bromide staining, and concentrations of redox status parameters (superoxide, reduced glutathione, lipid peroxidation) by colorimetric methods. The expression of genes involved in the biotransformation process and metabolite efflux was determined by qPCR method, while protein expression of glutathione synthetase and P-glycoprotein were analysed by immunocytochemistry. The analysis of cell death shows that snake venom dominantly leads cells to necrosis. Induction of apoptosis by L-amino acid oxidase was in correlation with oxidative disbalance in cancer cells. Gene expression profile of membrane transporters and CYP genes were different in each cell line and in correlation with their sensitivity of treatment. Our results show that L-amino acid oxidase from snake venom is a potent cytotoxic substance with pronounced pro-apoptotic activity. The inhibition of P-glycoprotein suggests that L-amino acid oxidase is a good substance for furter research of antitumor effect, with unexpressed potential for occurrence of drug resistance in vitro.

Evaluation of Antivenom Activity of Cassia alata Leaf Extract against Daboia Russelii Venom

Cassia alata, commonly known as candle bush, ringworm bush is an extensively distributed plant of the family Leguminosea. It is an annual and occasionally biannual herb, flowering in the sunshine and humid areas, with an average height of 1 to 4m. Biological activity in plants has been claimed to be effective as antidiabetic, antimicrobial, antioxidant, anti-inflammatory, anti-allergic, antimicrobial, analgesic, anti-ulcer, antiviral, antidepressants, hepatoprotective, antimalarial, anthelmintic, cardiovascular, and anesthetic properties. The ethanolic extract of plant was subjected first time for neutralization of snake venom activity. Primary phytochemical screening shows the existence of alkaloid, steroids, phenols, flavonoids, and triterpenoids. Ethanolic extract of Cassia alata plants was tested for antivenom activity against Daboia russelii venom. Various dose levels of leaf extract 200 and 400mg/kg showed significant neutralization of hemorrhagic activity, and at 400mg/kg leaf extract showed significant necrotizing activity in rats.

Clinical implications of ontogenetic differences in the coagulotoxic activity of Bothrops jararacussu venoms

Is snake venom activity influenced by size? This is a long-standing question that can have important consequences for the treatment of snake envenomation. Ontogenetic shifts in venom composition are a well-documented characteristic of numerous snake species. Although snake venoms can cause a range of pathophysiological disturbances, establishing the coagulotoxic profiles related to such shifts is a justified approach because coagulotoxicity can be deadly, and its neutralisation is a challenge for current antivenom therapy. Thus, we aimed to assess the coagulotoxicity patterns on plasma and fibrinogen produced by B othrops jararacussu venoms from individuals of different sizes and sex, and the neutralisation potential of SAB (anti bothropic serum produced by Butantan Institute). The use of a metalloproteinase inhibitor (Prinomastat) and a serine proteinase inhibitor (AEBSF) enabled us to determine the toxin class responsible for the observed coagulopathy: activity on plasma was found to be metalloprotease driven, while the activity on fibrinogen is serine protease driven. To further explore differences in venom activity, the activation of Factor X and prothrombin as a function of snake size was also evaluated. All the venoms exhibited a potent procoagulant effect upon plasma and were less potent in their pseudo-procoagulant clotting effect upon fibrinogen. On human plasma, the venoms from smaller snakes produced more rapid clotting than the larger ones. In contrast, the venom activity on fibrinogen had no relation with size or sex. The difference in procoagulant potency was correlated with the bigger snakes being proportionally better neutralized by antivenom due to the lower levels of procoagulant toxins, than the smaller. Thus, while the antivenom ultimately neutralized the venoms, proportionally more would be needed for an equal mass of venom from a small snake than a large one. Similarly, the neutralisation by SAB of the pseudo-procoagulant clotting effects was also correlated with relative potency, with the smaller and bigger snakes being neutralized proportional to potency, but with no correlation to size. Thromboelastography (TEG) tests on human and toad plasma revealed that small snakes’ venoms acted quicker than large snakes’ venom on both plasmas, with the action upon amphibian plasma consistent with smaller snakes taking a larger proportion of anuran prey than adults. Altogether, the ontogenetic differences regarding coagulotoxic potency and corresponding impact upon relative antivenom neutralisation of snakes with different sizes were shown, underscoring the medical importance of investigating ontogenetic changes in order to provide data crucial for evidence-based design of clinical management strategies.

Protective effect of epigallocatechin-3-gallate (EGCG) on toxic metalloproteinases-mediated skin damage induced by Scyphozoan jellyfish envenomation

Jellyfish stingings are currently raising serious public health concerns around the world. Hence, the search for an effective first aid reagent for the envenomation has been the goal of many investigators in the field. There have been a few previous reports of in vivo as well as in vivo studies suggesting the metalloproteinase activity of scyphozoan jellyfish venom, such as N. nomurai venom (NnV), plays a major role in the pathogenesis. These results have inspired us to develop a metalloproteinase inhibitor as a candidate for the treatment of Scyphozoan jellyfish envenomation. It has been previously demonstrated that the major polyphenol component in green tea, epigallocatechin-3-gallate (EGCG), can inhibit metalloproteinase activity of snake venoms. In fact, plant polyphenols as potential therapeutics have been shown to exert positive effects on neutralizing snake venoms and toxins. In the present study, we found that EGCG significantly inhibits the toxic proteases of NnV in a concentration-dependent manner. Human keratinocyte (HaCaT) and Human dermal fibroblast (HDF) cell culture studies showed that EGCG treatment can protect the cells from NnV-induced cytotoxicity which has been accompanied by the down-regulation of human matrix metalloproteinase (MMP)-2 and -9. Simulated rat NnV envenomation study disclosed that topical treatments with EGCG considerably ameliorated the progression of the dermonecrotic lesions caused by NnV. EGCG also reduced the activitions of tissue MMP-2 and MMP-9, which seem to be crucial players in the dermal toxic responses induced by NnV. Therefore, we propose that EGCG might be an effective therapeutic agent for the treatment of cutaneoous jellyfish symptoms.

The Crotoxin:SBA-15 Complex Down-Regulates the Incidence and Intensity of Experimental Autoimmune Encephalomyelitis Through Peripheral and Central Actions.

Crotoxin (CTX), the main neurotoxin from Crotalus durissus terrificus snake venom, has anti-inflammatory, immunomodulatory and antinociceptive activities. However, the CTX-induced toxicity may compromise its use. Under this scenario, the use of nanoparticle such as nanostructured mesoporous silica (SBA-15) as a carrier might become a feasible approach to improve CTX safety. Here, we determined the benefits of SBA-15 on CTX-related neuroinflammatory and immunomodulatory properties during experimental autoimmune encephalomyelitis (EAE), an animal model of multiple sclerosis that replicates several histopathological and immunological features observed in humans. We showed that a single administration of CTX:SBA-15 (54 μg/kg) was more effective in reducing pain and ameliorated the clinical score (motor impairment) in EAE animals compared to the CTX-treated EAE group; therefore, improving the disease outcome. Of interest, CTX:SBA-15, but not unconjugated CTX, prevented EAE-induced atrophy and loss of muscle function. Further supporting an immune mechanism, CTX:SBA-15 treatment reduced both recruitment and proliferation of peripheral Th17 cells as well as diminished IL-17 expression and glial cells activation in the spinal cord in EAE animals when compared with CTX-treated EAE group. Finally, CTX:SBA-15, but not unconjugated CTX, prevented the EAE-induced cell infiltration in the CNS. These results provide evidence that SBA-15 maximizes the immunomodulatory and anti-inflammatory effects of CTX in an EAE model; therefore, suggesting that SBA-15 has the potential to improve CTX effectiveness in the treatment of MS.