Venom Concentrations Research Articles

Intraspecific variation and influence of diet on the venom chemical profile of the Ectatomma brunneum Smith (Formicidae) ant evaluated by photoacoustic spectroscopy

Studies of venomous animals have shown that environmental and genetic factors contribute to determining the chemical composition of venom. It is well known that external effects cause differences in the toxicity, concentration, and prey specificity of venom. However, the influence of different factors on the chemical profile of Hymenoptera venom remains little explored. In view of this, the aim of this study was to evaluate intraspecific differences and the influence of diet on the chemical profile of Ectatomma brunneum venom using Fourier transform infrared photoacoustic spectroscopy. For the study of intraspecific variation of the venom, foragers were collected at locations with different environmental conditions, such as urban, intermediate, woodland and monoculture sites. To investigate the influence of diet on the venom, two colonies were sampled in the same area and were maintained in the laboratory under controlled diet conditions and at room temperature. The mid-infrared absorption spectra obtained were interpreted using discriminant function analysis. The results showed significant differences among the chemical profiles of the venoms of individuals from different environments and individuals exposed to a controlled diet in the laboratory, suggesting that venom composition was determined not only by genetic traits inherent to the species, but also by exogenous factors.

Eastern brown snake (Pseudonaja textilis) envenomation in dogs and cats: Clinical signs, coagulation changes, brown snake venom antigen levels and treatment with a novel caprylic acid fractionated bivalent whole IgG equine antivenom

This report describes the diagnosis and treatment of 16 confirmed cases of snakebite from the Australian eastern brown snake (Pseudonaja textilis) in dogs and cats. The clinical signs, brown snake venom antigen concentrations, coagulation parameters, and treatment outcomes following administration of an experimental caprylic acid fractionated bivalent whole IgG antivenom are documented. A brown snake venom antigen specific sandwich ELISA was used to retrospectively quantify venom levels in serum and urine. The characteristic clinical signs of envenomation in all cases were neurotoxicity to a variable extent and coagulation disturbances. The median serum venom concentration at presentation was 122 ng/mL and ranged from 1.9 to 3607 ng/mL. The median urine venom concentration at presentation was 55 ng/mL and ranged from 3.3 to 2604 ng/mL. Mechanical ventilation was used to successfully support respiration in three severely paralysed cases for 1–30 h. In four cases where serum samples were available post-antivenom treatment, venom was no longer detectable. Coagulation parameters measured on citrated plasma samples collected prior to antivenom from each case were abnormally prolonged to variable degrees in all cases. Three cases (2 dogs; 1 cat) were euthanized within four hours of presentation for either cost based reasons (2) or poor prognosis (1). One dog developed massive and potentially fatal pulmonary haemorrhage and was euthanazed. In vitro testing of the venom procoagulant neutralising efficacy of the experimental antivenom demonstrated it was 9.6–72 times more effective when compared to two other commercial veterinary antivenom products. This is the first detailed report of a case series of P. textilis envenomation in dogs and cats. The envenomation syndrome in dogs and cats differed to that reported humans, dominated by neurotoxicity and coagulopathy; unlike in humans, where coagulopathy is of primary clinical significance.

Characterization of the Rabbit as an In Vitro and In Vivo Model to Assess the Effects of Fibrinogenolytic Activity of Snake Venom on Coagulation.

Several invitro investigations have demonstrated that anticoagulant effects of fibrinogenolytic snake venom metalloproteinases have been abrogated in human plasma by modifying fibrinogen with iron (Fe) and carbon monoxide (CO) to prevent catalysis or by directly inhibiting these enzymes with CO. To translate these findings, we chose to assess the rabbit as a model of envenomation with Crotalus atrox venom. It was determined with thrombelastography that 15 times the concentration of venom noted to compromise coagulation in plasma invitro was required to cause coagulopathy invivo, likely secondary to venom binding to blood cells and being cleared from the circulation rapidly. Unlike human plasma, rabbit plasma pre-treated with Fe/CO was not protected from fibrinogenolysis by venom. Consequently, the administration of purified human fibrinogen (with or without Fe/CO) would be required before venom administration to rabbits. Of greater interest, venom exposed to CO had complete loss of fibrinogenolytic effect in rabbit plasma and partial loss of activity in whole blood, indicative of unbinding of CO from venom and binding to haemoglobin. Thus, venom exposed to CO could remain partially or completely inhibited in whole blood long enough for clearance from the circulation, allowing rabbits to be a useful model to test the efficacy of regional CO administration to the bite site. Future investigations are planned to test these novel approaches to attenuate venom-mediated coagulopathy in the rabbit.

A New Approach to Antivenom Preparation Using Chitosan Nanoparticles Containing EchisCarinatus Venom as A Novel Antigen Delivery System.

In recent years, use of biodegradable polymers based nanoparticles has received high interest in the development of vaccines delivery vehicles. The aim of study was to prepare chitosan nanoparticles (CS NPs) for loading Echis carinatus (EC) venom and evaluate their potential as an adjuvant and antigen delivery system on a pilot scale. CS NPs were prepared using ionic gelation method, and their characteristics were optimized. Venom-loaded CS NPs prepared under optimum conditions and traditional venom-loaded adjuvants were used to hyperimmunization of horse. Under optimum conditions, particle size, polydispersity index (PDI), and zeta potential of CS NPs were 127.9 ± 15 nm, 0.29, and +19.8 ± 1.92 mV, while those of venom-loaded CS NPs were 182.4 ± 20 nm, 0.35, +26.8 ± 1.98 mv, respectively. All CS NPs had integrated surface and good morphology. Optimum loading concentration of EC venom was 500 µg/mL. The loading capacity (LC) and loading efficiency (LE) were 87% and 94%, respectively, and release profile of venom-loaded CS NPs showed suitable correlation with Higuchi kinetics. Stability test showed good stability of the venom encapsulated in CS NPs. Furthermore, antivenom plasma obtained using the new antigen delivery system had significantly higher potency (P < 0.05) for neutralizing the venom than that obtained using conventional system. These results suggested that venom-loaded CS NPs could be a suitable alternative to conventional adjuvant for development antivenom.

Histological alterations in Kidney and Liver of laboratory mice following intramuscular injection of Montevipera bornmuelleri (Werner, 1898) Venom.

Histopathological changes after bites of the Montivipera bornmuelleri viper, endemic to high altitudes areas of Lebanon, have not yet been investigated. Our study focuses on histological changes and irreversible damages in the kidney and liver of white laboratory Balb/c mice that received an intramuscular injection of lyophilized venom diluted in saline solution (NaCl 0.9%). Different venom concentration doses ranging from 0.25 mg/kg to 15mg/kg in a total injection volume of 100µl was injected intramuscularly (IM) into 5 groups of mice. After dissection, observations showed no macroscopically identifiable damages in any of the organs studied. However, tissue samples from the liver and the kidney were obtained for histological studies at various time intervals following the venom injection. The histological study was carried out using the Bouin solution (fixing bath), followed by dehydration in alcohol. Paraffin-embedded sections were stained using hemalun-easine. Tissues from 6 control mice, which received only an injection of saline solution, were also examined. The common histological alterations observed microscopically in the liver and the kidney were: pycnotic nuclei, necrosis, vacuolization, cytoplasmic destruction, edema, hemorrhage and congestion of blood vessels. Moreover, inflammatory infiltration of lymphocytic cells was observed in the prevascular regions of both organs. The histological changes observed appeared within 1h and intensified with time. These changes were proportional to the dose of the venom injected into the laboratory mice. Our results on what happens in the kidney and liver of mice after injecting the venom of M. bornmuelleri had many similarities with the effect of venom of other vipers (e. g. Daboia palestinea, Bitis ssp, Bothrops moujenis etc…) observed by others authors.

Rattlesnake Crotalus molossus nigrescens venom induces oxidative stress on human erythrocytes

BackgroundGlobally, snake envenomation is a well-known cause of death and morbidity. In many cases of snakebite, myonecrosis, dermonecrosis, hemorrhage and neurotoxicity are present. Some of these symptoms may be provoked by the envenomation itself, but others are secondary effects of the produced oxidative stress that enhances the damage produced by the venom toxins. The only oxidative stress effect known in blood is the change in oxidation number of Fe (from ferrous to ferric) in hemoglobin, generating methemoglobin but not in other macromolecules. Currently, the effects of the overproduction of methemoglobin derived from snake venom are not extensively recorded. Therefore, the present study aims to describe the oxidative stress induced by Crotalus molossus nigrescens venom using erythrocytes.MethodsHuman erythrocytes were washed and incubated with different Crotalus molossus nigrescens venom concentrations (0–640 μg/mL). After 24 h, the hemolytic activity was measured followed by attenuated total reflectance-Fourier transform infrared spectroscopy, non-denaturing PAGE, conjugated diene and thiobarbituric acid reactive substances determination.ResultsLow concentrations of venom (<10 μg/mL) generates oxyhemoglobin release by hemolysis, whereas higher concentrations produced a hemoglobin shift of valence, producing methemoglobin (>40 μg/mL). This substance is not degraded by proteases present in the venom. By infrared spectroscopy, starting in 80 μg/mL, we observed changes in bands that are associated with protein damage (1660 and 1540 cm−1) and lipid peroxidation (2960, 2920 and 1740 cm−1). Lipid peroxidation was confirmed by conjugated diene and thiobarbituric acid reactive substance determination, in which differences were observed between the control and erythrocytes treated with venom.ConclusionsCrotalus molossus nigrescens venom provokes hemolysis and oxidative stress, which induces methemoglobin formation, loss of protein structure and lipid peroxidation.

Intracellular zinc trafficking and metallothionein gene activation in HUVEC treated with Crotalus atrox venom

Hemorrhagic snake venom, such as Crotalus atrox, destroys local tissue and disrupts hemostasis. In this study, we examined zinc trafficking in human umbilical vein endothelial cells (HUVEC) stimulated with C. atrox snake venom. We utilized MTS cytotoxicity assays to monitor the cytotoxic range of C. atrox venom. HUVEC monolayers stimulated with 10 μg/ml C. atrox venom for 3 hours displayed cellular retraction, which coincided with 53.0±6.5 percent viability. In contrast, venom concentrations of 100 μg/ml produced a complete disruption of cellular adherence and viability decreased to 36.6±1.0. Venom induce cellular retraction involves cytoskeletal rearrangements. Therefore, we used the zinc probe FluorZin‐3AM to compare intracellular free zinc in HUVEC stimulated with 10 μg/ml C. atrox venom or 1 μg/ml cytochalasin D for 1 hour. Fluorescent intensity analysis returned values of 287.1±57.7 for C. atrox and 261.7±33.3 for cytochalasin D, demonstrating an increase in labile zinc compared to non‐stimulated controls. Labile intracellular zinc or other metals can induce the gene activation of intracellular metal binding proteins known as metallothioneins. Thus, we measured the gene and protein expression of metallothionein 1X (MT1X) and metallothionein 2A (MT2A) in HUVEC stimulated with C. atrox venom. MT2A gene expression increase by 4.4±0.41 fold compared to 96.1±3.0 for MT1X. This data suggest cell death from C. atrox venom involves intracellular zinc trafficking, and metallothionein gene activation.Support or Funding InformationCETL, OVPR Grant

A survey on some biochemical and pharmacological activities of venom from two Colombian colubrid snakes, Erythrolamprus bizona (Double-banded coral snake mimic) and Pseudoboa neuwiedii (Neuwied's false boa)

Colombian colubrid snake venoms have been poorly studied. They represent a great resource of biological, ecological, toxinological and pharmacological research. We assessed some enzymatic properties and neuromuscular effects of Erythrolamprus bizona and Pseudoboa neuwiedii venoms from Colombia. Proteolytic, amidolytic and phospholipase A2 (PLA2) activities were analyzed using colorimetric assays and the neuromuscular activity was analyzed in chick biventer cervicis (BC) preparations. The venom of both species showed very low PLA2 and amidolytic activities; however, both exhibited high proteolytic activity, which in E. bizona venom surpassed that of P. neuwiedii venom. E. bizona and P. neuwiedii venoms provoked partial neuromuscular blockade, which was more prominent in P. neuwiedii venom. E. bizona venom (30 μg/ml) induced a significant potentiation of the contracture response to exogenous ACh (110 μM), which was not accompanied by twitch height alteration, whereas the highest venom concentration (100 μg/ml) inhibited contracture responses to both ACh and KCl (40 mM). In contrast, P. neuwiedii venom (30 and 100 μg/ml) caused significant reduction in the contracture responses to exogenous ACh and KCl. The morphological analyses showed high myotoxic effects in the muscle fibers of BC incubated with either venoms; however, they are more prominent in the P. neuwiedii venom. Our results suggest that the myotoxicity of the venom of the two Colombian species can be ascribed to their high proteolytic activity. An interesting data was the potentiation of the ACh-induced contracture, but not the twitch height, caused by E. bizona venom, at a concentration that is harmless to muscle fibers integrity. This phenomenon remains to be further elucidated, and suggest that a possible involvement of post-synaptic receptors cannot be discarded. This work is a contribution to expand the knowledge on colubrid venoms; it allows envisaging that the two venoms offer the potential to go further in the identification of their components and biological targets.

Bee venom induces apoptosis and suppresses matrix metaloprotease-2 expression in human glioblastoma cells

Glioblastoma is the most common malignant brain tumor representing with poor prognosis, therapy resistance and high metastasis rate. Increased expression and activity of matrix metalloproteinase-2, a member of matrix metalloproteinase family proteins, has been reported in many cancers including glioblastoma. Inhibition of matrix metalloproteinase-2 expression has resulted in reduced aggression of glioblastoma tumors in several reports. In the present study, we evaluated effect of bee venom on expression and activity of matrix metalloproteinase-2 as well as potential toxicity and apoptogenic properties of bee venom on glioblastoma cells. Human A172 glioblastoma cells were treated with increasing concentrations of bee venom. Then, cell viability, apoptosis, matrix metalloproteinase-2 expression, and matrix metalloproteinase-2 activity were measured using MMT assay, propidium iodide staining, real time-PCR, and zymography, respectively. The IC50 value of bee venom was 28.5μg/ml in which it leads to decrease of cell viability and induction of apoptosis. Incubation with bee venom also decreased the expression of matrix metalloproteinase-2 in this cell line (p<0.05). In zymography, there was a reverse correlation between bee venom concentration and total matrix metalloproteinase-2 activity. Induction of apoptosis as well as inhibition of matrix metalloproteinase-2 activity and expression can be suggested as molecular mechanisms involved in cytotoxic and antimetastatic effects of bee venom against glioblastoma cells.

Montivipera bornmuelleri venom selectively exhibits high cytotoxic effects on keratinocytes cancer cell lines

ContextThe Viperidae family venom is a rich source of bioactive compounds such as many proteases, which cause tissue necrosis and affect mostly the vascular system. However, the venom exhibits therapeutic potentials and has contributed to the development of some medical drugs. Specifically, the Montivipera bornmuelleri venom has shown to exhibit antibacterial, pro-inflammatory and antifungal activities. ObjectiveThis work evaluates the cytotoxic effect of the M. bornmuelleri venom on human-derived keratinocytes including the non-tumorigenic HaCaT, the benign A5 and the low-grade malignant II4 cells. Materials and methodsThe toxicity of different venom concentrations (0.9, 1.87, 3.75, 7.5, 15, 30 and 60μg/mL) and their effect on the viability of the cells lines were assessed using the Lactate Dehydrogenase (LDH) activity and the Trypan blue tests after 24h of incubation. ResultsThe venom was able to reduce the viability of all cell lines in a dose dependent manner with the HaCat cells being the least affected. For example, the 60μg/mL dose induced a more significant decrease the viability of A5 (44%) and II4 (21.33%) keratinocytes as compared to HaCaT cells (70.63%). Also, this venom showed a higher cytotoxic activity on the A5 (52.45%) and II4 (98.67%) cells as compared to HaCaT cells (30.14%) with an IC50 estimated at 10μg/mL on II4 and at 60μg/mL on benign A5. Discussion and conclusionThose differential cytotoxic effects of the M. bornmuelleri venom pave the road for more advanced studies which might unravel the potential anticancer effects of this venom.

Böse Kräfte im brasilianischen Paradies: Gift, Leben und Tod bei dem Besuch Stefan Zweigs am Schlangeninstitut von Butantan

It is well known that Stefan Zweig had a passion for Brazil, in particular for Rio de Janeiro. He was much more reserved, however, about Brazil’s largest city, São Paulo. Yet his visit to the Butantan snake institute in São Paulo was not inconsequential. This article shows that the lukewarm Brazilian reception of Zweig’s book Brasilien: Ein Land der Zukunft(1941) may in part be attributed to his failure to write more enthusiastically about Butantan and to show a better understanding of the importance of the scientific achievements by the institute’s founder, Vital Brazil, to the nation’s self-consciousness. Zweig’s interest in a flask with a high concentration of snake venom resonates with the many mentions of poison in his work and anticipates his future death by suicide. The article also suggests a different interpretation of Zweig’s suicide as a (potential) form of regeneration rather than resignation.

Simplification of intradermal skin testing in Hymenoptera venom allergic children

BackgroundThe direct comparison between children and adults with Hymenoptera venom anaphylaxis (HVA) has never been extensively reported. Severe HVA with IgE-documented mechanism is the recommendation for venom immunotherapy, regardless of age. ObjectiveTo determine the differences in the basic diagnostic profile between children and adults with severe HVA and its practical implications. MethodsWe reviewed the medical records of 91 children and 121 adults. ResultsBee venom allergy was exposure dependent, regardless of age (P < .001). Atopy was more common in children (P = .01), whereas cardiovascular comorbidities were present almost exclusively in adults (P = .001). In the bee venom allergic group, specific IgE levels were significantly higher in children (29.5 kUA/L; interquartile range, 11.30-66.30 kUA/L) compared with adults (5.10 kUA/L; interquartile range, 2.03–8.30 kUA/L) (P < .001). Specific IgE levels for culprit insect venom were higher in bee venom allergic children compared with the wasp venom allergic children (P < .001). In adults, intradermal tests revealed higher sensitivity, accompanied by larger area of skin reactions, regardless of type of venom. At concentrations lower than 0.1 μg/mL, 16% of wasp venom allergic children and 39% of bee venom allergic children had positive intradermal test results. The median tryptase level was significantly higher in adults than in children for the entire study group (P = .002), as well as in bee (P = .002) and wasp venom allergic groups (P = .049). ConclusionThe basic diagnostic profile in severe HVA reactors is age dependent. Lower skin test reactivity to culprit venom in children may have practical application in starting the intradermal test procedure with higher venom concentrations.

Clinical and Pharmacological Investigation of Myotoxicity in Sri Lankan Russell's Viper (Daboia russelii) Envenoming.

BackgroundSri Lankan Russell’s viper (Daboia russelii) envenoming is reported to cause myotoxicity and neurotoxicity, which are different to the effects of envenoming by most other populations of Russell’s vipers. This study aimed to investigate evidence of myotoxicity in Russell’s viper envenoming, response to antivenom and the toxins responsible for myotoxicity.Methodology and FindingsClinical features of myotoxicity were assessed in authenticated Russell’s viper bite patients admitted to a Sri Lankan teaching hospital. Toxins were isolated using high-performance liquid chromatography. In-vitro myotoxicity of the venom and toxins was investigated in chick biventer nerve-muscle preparations. Of 245 enrolled patients, 177 (72.2%) had local myalgia and 173 (70.6%) had local muscle tenderness. Generalized myalgia and muscle tenderness were present in 35 (14.2%) and 29 (11.8%) patients, respectively. Thirty-seven patients had high (>300 U/l) serum creatine kinase (CK) concentrations in samples 24h post-bite (median: 666 U/l; maximum: 1066 U/l). Peak venom and 24h CK concentrations were not associated (Spearman’s correlation; p = 0.48). The 24h CK concentrations differed in patients without myotoxicity (median 58 U/l), compared to those with local (137 U/l) and generalised signs/symptoms of myotoxicity (107 U/l; p = 0.049). Venom caused concentration-dependent inhibition of direct twitches in the chick biventer cervicis nerve-muscle preparation, without completely abolishing direct twitches after 3 h even at 80 μg/ml. Indian polyvalent antivenom did not prevent in-vitro myotoxicity at recommended concentrations. Two phospholipase A2 toxins with molecular weights of 13kDa, U1-viperitoxin-Dr1a (19.2% of venom) and U1-viperitoxin-Dr1b (22.7% of venom), concentration dependently inhibited direct twitches in the chick biventer cervicis nerve-muscle preparation. At 3 μM, U1-viperitoxin-Dr1a abolished twitches, while U1-viperitoxin-Dr1b caused 70% inhibition of twitch force after 3h. Removal of both toxins from whole venom resulted in no in-vitro myotoxicity.ConclusionThe study shows that myotoxicity in Sri Lankan Russell’s viper envenoming is mild and non-life threatening, and due to two PLA2 toxins with weak myotoxic properties.

Evaluation of the antiviral effect of bee venom on rabies virus

It is an interesting thing to known the effect of natural matter as bee venom as antiviral agent and to any extent it couldbe used in case of experimental rabies infection. In vitro study revealed that different concentrations of bee venom (startedfrom the original concentration “1mg/ml” up to 1:1000) did not show any cell growth retarders or cellular changesshowing normal growth rate and normal cell shape. 1mg/ml and 100μgm/ml of bee venom were able to inhibit thereplication of 100 TCID50 of rabies virus (ERA strain) in using baby hamster kidney BHK cells while 10 and 1μgm/mlwere negative. In vivo study showed that mice received rabies immune globulin and BV were able to withstand the rabisinfection when the they were administrated on the o, 1st, 2nd and 3rd day post infection showing protection rate of 90 and80% respectively but those mice received the treatment on the following days did not survive the infection and showedparalysis of the hind limbs by the 4th day and died by the 6-7th day post infection. It could be concluded that bee venomcould be used in case of rabies infection when administrated on the suitable time post exposure

Australian taipan (Oxyuranus spp.) envenoming: clinical effects and potential benefits of early antivenom therapy – Australian Snakebite Project (ASP-25)

Context: Taipans (Oxyuranus spp.) are medically important venomous snakes from Australia and Papua New Guinea. The objective of this study was to describe taipan envenoming in Australian and its response to antivenom.Methods: Confirmed taipan bites were recruited from the Australian Snakebite Project. Data were collected prospectively on all snakebites, including patient demographics, bite circumstances, clinical effects, laboratory results, complications and treatment. Blood samples were taken and analysed by venom specific immunoassay to confirm snake species and measure venom concentration pre- and post-antivenom.Results: There were 40 confirmed taipan bites: median age 41 years (2–85 years), 34 were males and 21 were snake handlers. Systemic envenoming occurred in 33 patients with neurotoxicity (26), complete venom induced consumption coagulopathy (VICC) (16), partial VICC (15), acute kidney injury (13), myotoxicity (11) and thrombocytopenia (7). Venom allergy occurred in seven patients, three of which had no evidence of envenoming and one died. Antivenom was given to 34 patients with a median initial dose of one vial (range 1–4), and a median total dose of two vials (range 1–9). A greater total antivenom dose was associated with VICC, neurotoxicity and acute kidney injury. Early antivenom administration was associated with a decreased frequency of neurotoxicity, acute kidney injury, myotoxicity and intubation. There was a shorter median time to discharge of 51 h (19–432 h) in patients given antivenom <4 h post-bite, compared to 175 h (27–1104 h) in those given antivenom >4 h. Median peak venom concentration in 25 patients with systemic envenoming and a sample available was 8.4 ng/L (1–3212 ng/L). No venom was detected in post-antivenom samples, including 20 patients given one vial initially and five patients bitten by inland taipans.Discussion: Australian taipan envenoming is characterised by neurotoxicity, myotoxicity, coagulopathy, acute kidney injury and thrombocytopenia. One vial of antivenom binds all measurable venom and early antivenom was associated with a favourable outcome.

Investigation of in vivo potential of scorpion venom against skin tumorigenesis in mice via targeting markers associated with cancer development.

Cancer is the leading cause of morbidity and mortality all over the world in spite of the advances made in its management. In this study, we investigated the in vivo anti-tumorigenic potential of the venom obtained from a medically important scorpion species Leiurus quinquestriatus on chemically induced skin cancer in mice. Animals were divided into five groups, with 13 animals in each group. All the treatments were given topically on the shaved dorsal surface of the skin. Animals in Group 1 received vehicle only (0.2 mL acetone). Moreover, 7,12-dimethylbenz[a]anthracene (DMBA, 400 nmol per mouse) was applied to all the animals in the remaining four groups. After 1 week, different concentrations of venom (17.5 μg, 35 μg, and 52.5 μg per animal) were applied to each animal in the Groups III–V. Thirty minutes after the application of venom, croton oil was applied on the same position where venom was administered to the animals of Groups III–V. Animals in Group II were treated as the positive control (without venom) and received croton oil as in Groups III–V. The findings of this study revealed that venom extract of L. quinquestriatus inhibits DMBA + croton oil-induced mouse skin tumor incidence and tumor multiplicity. Venom treatment also decreased the expression of proinflammatory cytokines. Immunohistochemistry results showed a downregulation of the expression of molecular markers such as Ki-67, nuclear factor kappa-B, cyclooxygenase-2, B-cell lymphoma-2, and vascular endothelial growth factor, in venom-treated animals. Our findings suggest that the venom of L. quinquestriatus possesses in vivo anticancer potential and may be used in the development of anticancer molecules.

Snake venom causes apoptosis by increasing the reactive oxygen species in colorectal and breast cancer cell lines.

Snake venom possesses various kinds of proteins and neurotoxic polypeptides, which can negatively interfere with the neurotransmitter signaling cascade. This phenomenon occurs mainly due to the blocking of ion channels in the body system. Envenomation prevents or severely interrupts nerve impulses from being transmitted, inhibition of adenosine triphosphate synthesis, and proper functioning of the cardiac muscles. However, some beneficial properties of venoms have also been reported. The aim of this study was to examine the snake venom as an anticancer agent due to its inhibitory effects on cancer progression such as cell motility, cell invasion, and colony formation. In this study, the effect of venoms on phenotypic changes and the change on molecular level in colorectal and breast cancer cell lines were examined. A reduction of 60%–90% in cell motility, colony formation, and cell invasion was observed when these cell lines were treated with different concentrations of snake venom. In addition, the increase in oxidative stress that results in an increase in the number of apoptotic cancer cells was significantly higher in the venom-treated cell lines. Further analysis showed that there was a decrease in the expression of pro-inflammatory cytokines and signaling proteins, strongly suggesting a promising role for snake venom against breast and colorectal cancer cell progression. In conclusion, the snake venoms used in this study showed significant anticancer properties against colorectal and breast cancer cell lines.

The role of the erythrocyte cytoskeleton protein spectrin during invasion by Francisella tularensis.

Francisella tularensis is classified as a Category A bioterrorism agent by the Centers for Disease Control and Prevention. Inhaling as few as ten of these bacteria can cause acute, lethal pneumonia. Studies using mouse models of infection have shown that erythrocyte invasion is a novel feature of F. tularensis during infection; however, the mechanism by which this bacterium enters red blood cells is unknown. Cytoskeletal rearrangement of other host cells such as macrophages and hepatocytes is required for entry of F. tularensis. Therefore, in this study, we evaluated the role of the major erythrocyte cytoskeletal component, spectrin, in red blood cell invasion. To test this, human erythrocytes were treated with venom from the Blue-bellied black snake (Pseudechis guttatus), which disrupts the spectrin in the cytoskeleton. Treatment with this venom significantly reduced the number of intra-erythrocytic bacteria suggesting that spectrin is involved in erythrocyte invasion. Importantly, the concentrations of venom used in this study did not reduce the number of intact erythrocytes. This is the first study showing the involvement of an erythrocyte protein during invasion by F. tularensis.

Rapid and selective detection of experimental snake envenomation – Use of gold nanoparticle based lateral flow assay

In this study, we have developed a gold nanoparticle based simple, rapid lateral flow assay (LFA) for detection of Indian Cobra venom (CV) and Russell’s viper venom (RV). Presently, there is no rapid, reliable, and field diagnostic test available in India, where snake bite cases are rampant. Therefore, this test has an immense potential from the public health point of view. The test is based on the principle of the paper immunochromatography assay for detection of two snake venom species using polyvalent antisnake venom antibodies (ASVA) raised in equines and species-specific antibodies (SSAbs) against venoms raised in rabbits for conjugation and impregnation respectively. The developed, snake envenomation detection immunoassay (SEDIA) was rapid, selective, and sensitive to detect venom concentrations up to 0.1 ng/ml. The functionality of SEDIA strips was confirmed by experimental envenomation in mice and the results obtained were specific for the corresponding venom. The SEDIA has a potential to be a field diagnostic test to detect snake envenomation and assist in saving lives of snakebite victims.

Efficacy of Indian polyvalent snake antivenoms against Sri Lankan snake venoms: lethality studies or clinically focussed in vitro studies.

In vitro antivenom efficacy studies were compared to rodent lethality studies to test two Indian snake antivenoms (VINS and BHARAT) against four Sri Lankan snakes. In vitro efficacy was tested at venom concentrations consistent with human envenoming. Efficacy was compared statistically for one batch from each manufacturer where multiple vials were available. In binding studies EC50 for all VINS antivenoms were less than BHARAT for D. russelii [553 μg/mL vs. 1371 μg/mL;p = 0.016), but were greater for VINS antivenoms compared to BHARAT for N. naja [336 μg/mL vs. 70 μg/mL;p < 0.0001]. EC50 of both antivenoms was only slighty different for E. carinatus and B. caeruleus. For procoagulant activity neutralisation, the EC50 was lower for VINS compared to BHARAT - 60 μg/mL vs. 176 μg/mL (p < 0.0001) for Russell’s viper and 357 μg/mL vs. 6906μg/mL (p < 0.0001) for Saw-scaled viper. Only VINS antivenom neutralized in vitro neurotoxicity of krait venom. Both antivenoms partially neutralized cobra and didn’t neutralize Russell’s viper neurotoxicity. Lethality studies found no statistically significant difference in ED50 values between VINS and BHARAT antivenoms. VINS antivenoms appeared superior to BHARAT at concentrations equivalent to administering 10 vials antivenom, based on binding and neutralisation studies. Lethality studies were inconsistent suggesting rodent death may not measure relevant efficacy outcomes in humans.