Pro-inflammatory cytokines gene expression in liver and kidneys of rats exposed to a sub-lethal dose of Bitis arietans snake venom.

Bitis arietans (Puff adder) is a poisonous snake and its bite causes pain, edema, blistering, tissue damage and neutrophilia. There are limited studies on inflammatory process involved in Bitis arietans envenomation. We therefore investigated the role of proinflammatory cytokines in Bitis arietans venom (BAV)-induced liver and kidney toxicities in rats. Adult male Sprague Dawley rats were treated with BAV (0.5 mg/kg) and were sacrificed after specific time intervals (2 h, 24 h, 1 week). Blood samples were collected for liver and renal function tests and tissues were collected for histopathology and gene expression analysis of IL-1ß, IL-6, and TNF-α in liver and kidneys. There was no significant difference in serum ALT activities among different treatment groups. Serum AST was significantly increased at 24 h following BAV injection. In both organs, injection of BAV resulted in mild inflammatory cell infiltration at 2 h post-dosing which normalized after 1 week. In liver, there was a significant increase in IL-1ß expression in BAV-treated rats at 2 and 24 h post-dosing that reduced after one week. Significant increases in IL-6 and TNF-α were observed at 24 h and 1 week after BAV exposure. In kidneys, there were significant increases in IL-1ß and TNF-α expression at 24 h that subsided after 1 week. In conclusion, a single sub-lethal dose of BAV caused an acute phase inflammation in liver and kidneys. It is most probable that a higher dose of BAV may result in greater and irreversible damage to these organs.

Intraspecific venom variation in the medically important puff adder (Bitis arietans): Comparative venom gland transcriptomics, in vitro venom activity and immunological recognition by antivenom.

BACKGROUND: Variation in snake venoms is well documented, both between and within species, with intraspecific venom variation often correlated with geographically distinct populations. The puff adder, Bitis arietans, is widely distributed across sub-Saharan Africa and into the Arabian Peninsula where it is considered a leading cause of the ~310,000 annual snakebites across the region, with its venom capable of causing substantial morbidity and mortality. Despite its medical importance and wide geographic distribution, there is little known about venom variation between different B. arietans populations and the potential implications of this variation on antivenom efficacy. METHODOLOGY: We applied a range of analyses, including venom gland transcriptomics, in vitro enzymatic assays and reverse phase chromatography to comparatively analyse B. arietans venoms originating from Nigeria, Tanzania, and South Africa. Immunological assays and in vitro enzymatic neutralisation assays were then applied to investigate the impact of venom variation on the potential efficacy of three antivenom products; SAIMR Polyvalent, EchiTAb-Plus and Fav-Afrique. FINDINGS: Through the first comparison of venom gland transcriptomes of B. arietans from three geographically distinct regions (Nigeria, Tanzania, and South Africa), we identified substantial variation in toxin expression. Findings of venom variation were further supported by chromatographic venom profiling, and the application of enzymatic assays to quantify the activity of three pathologically relevant toxin families. However, the use of western blotting, ELISA, and in vitro enzymatic inhibition assays revealed that variation within B. arietans venom does not appear to substantially impact upon the efficacy of three African polyvalent antivenoms. CONCLUSIONS: The large distribution and medical importance of B. arietans makes this species ideal for understanding venom variation and the impact this has on therapeutic efficacy. The findings in this study highlight the likelihood for considerable venom toxin variation across the range of B. arietans, but that this may not dramatically impact upon the utility of treatment available in the region.

Viber Snakebite Presenting with Cerebral Venous Thrombosis: A Very Rare Case Report from Somalia.

Cerebral sinus venous thrombosis (CSVT) is an uncommon and potentially life-threatening neurological disorder that is often missed because its clinical and radiological symptoms are not specific. Snake bites are a rare cause of cerebral venous sinus thrombosis that must be recognized and treated promptly to improve survival. Here, we present a case of a 30-year-old male patient who had cerebral venous thrombosis after snake bite in the rural area of southern Somalia. After close monitoring with anticoagulation, the condition of the patient improved and discharged from the hospital with full of consciousness. There are only a few cases reported in the literature of snake bites causing cerebral venous thrombosis.

Cardiotoxic Effects of Lachesis acrochorda Snake Venom in Anesthetized Wistar Rats.

Ophidism is a public health problem in tropical countries, occurring predominantly in rural areas. In Colombia, among the species responsible for snakebite envenomation, inflicting high mortality, is the Chocoan bushmaster, Lachesis acrochorda, better known locally by the names "verrugosa (warty)" and "pudridora (rot-causing)". In this research, the cardiotoxic effect of the venom of L. acrochorda in male Wistar rats weighing 230 ± 20 g was evaluated. A statistical design of randomized blocks was implemented with three treated groups, injected with lyophilized venom (doses of 3.22 µg/g, 6.43 µg/g, 12.86 µg/g), and a control group injected with 0.9% saline solution. Electrocardiographic (ECG) recordings were taken from the anesthetized animals, revealing an increase in the amplitude of the P and T waves and an increase in the duration of the QT intervals in the electrocardiographic recordings. These increases were not observed in the control biomodels. In the analysis of the CK and CK-MB enzyme levels, increases were also observed in the levels of cardiac isoenzymes in the injected animals, but none in the control animals. The histopathological analyses carried out reveal that the injected animals showed effects such as interfibrillar and perivascular edema, cellular shortening of the cardiomyocytes, foci with tissue destructuring, and necrosis with contraction bands. In conclusion, the venom of the Lachesis acrochorda snake increases the P and T waves and the QT interval and increases the CK and CK-MB enzymes in the blood. Additionally, it causes interfibrillar and perivascular edema in the cardiac tissue, cardiocytolysis, and contraction bands.

Tiny but Mighty: Vipera ammodytes meridionalis (Eastern Long-Nosed Viper) Ontogenetic Venom Variations in Procoagulant Potency and the Impact on Antivenom Efficacies.

The Eastern Long-Nosed Viper (Vipera ammodytes meridionalis) is considered one of the most venomous snakes in Europe. However, it is unknown whether ontogenetic variation in venom effects occurs in this subspecies and how this may impact antivenom efficacy. In this study, we compared the procoagulant activities of V. a. meridionalis venom on human plasma between neonate and adult venom phenotypes. We also examined the efficacy of three antivenoms-Viperfav, ViperaTAb, and Inoserp Europe-across our neonate and adult venom samples. While both neonate and adult V. a. meridionalis venoms produced procoagulant effects, the effects produced by neonate venom were more potent. Consistent with this, neonate venom was a stronger activator of blood-clotting zymogens, converting them into their active forms, with a rank order of Factor X >> Factor VII > Factor XII. Conversely, the less potent adult venom had a rank order of FXII marginally more activated than Factor VII, and both much more so than Factor X. This adds to the growing body of evidence that activation of factors besides FII (prothrombin) and FX are significant variables in reptile venom-induced coagulopathy. Although all three examined antivenoms displayed effective neutralization of both neonate and adult V. a. meridionalis venoms, they generally showed higher efficacy on adult venom than on neonate venom. The ranking of antivenom efficacy against neonate venom, from the most effective to the least effective, were Viperfav, Inoserp Europe, ViperaTAb; for adult venom, the ranking was Inoserp Europe, Viperfav, ViperaTAb. Our data reveal ontogenetic variation in V. a meridionalis, but this difference may not be of clinical concern as antivenom was effective at neutralizing both adult and neonate venom phenotypes. Regardless, our results highlight a previously undocumented ontogenetic shift, likely driven by the documented difference in prey preference observed for this species across age classes.

Obscure properties of a traditional herb Pittosporum neelgherrense used to treat snakebite envenoming against Daboia russelli venoms.

In tropical nations, snakebite envenomation is a significant public health issue with negative human and social effects. This is due to three factors: 1) more species of the most hazardous snakes are present; 2) emergency medical assistance is not readily available; and 3) inadequate health care. The problems caused by snakebite envenomation have been partially resolved by immunotherapy. An extensive collection of medicinal herbs is recognized to have antivenomous properties in traditional medicine. However, very few species have undergone scientific investigation, and even fewer have had their active components separated and structurally and functionally defined. In this work, the anti-venom potential of hot and cold aqueous extracts from Pittosporum neelgherrense is evaluated using an in-vitro model. The experimental results showed that 4H-pyran-4-one, 2,3-dihydro-3,5-dihydroxy-6-methyl-(11.20), 1-Undecanol (16.38), Lauryl acetate (18.25), and Cyclotridecane (19.14) were phytochemical substances whose chemical structures were recognized by GCMS. The Direct and Indirect hemorrhagic activity was found to be completely neutralized by P. neelgherrense extract (44.61% hot plant extract & 55.38% cold plant extract) and the zone (2.4 mm), respectively. The neutralization of venoms was indicated by the zone (0.5-0.9 cm) of hydrolysis production of proteolytic activity. Additionally, the results of the gelatine liquefaction study demonstrated that clot formation was not triggered by venom at low concentrations (50:50) but was instead brought on by higher concentrations. The present study suggested that the neutralization of venom by hot water extracts of P. neelgherrense is a potentially therapeutic application.

Venom-induced myocarditis: An unusual case attributable to Vipera aspis bite.

Venomous bites are medical emergencies that may result in life-threatening clinical effects. Cardiovascular complications are uncommon but they can be dangerous if not early detected and treated. Cerebral and myocardial infarction are described; myocarditis as consequence of viper envenomation in humans are very rare, almost anedoctal. We present the case of a 33-year-old man, working as keeper in a reptile zoo, who arrived after a viper bite of the Vipera aspis species, on the left wrist. The patient presented with clouded sensorium, edema of the lips and tongue, rapidly worsened with angioedema, and the need for oro-tracheal intubation; severe thrombocytopenia and anemia were treated with transfusions of platelet, plasma and red blood cells. The left hand and arm worsened, with compartment syndrome, treated with surgical fasciotomy. From a cardiological point of view, the patient presented a sudden drop in blood pressure, electrocardiographic anterior and infero-lateral ST depression, pericardial effusion and hypokinesia of the interventricular septum on echocardiography, and a significant increase in troponin T. Cardiac magnetic resonance imaging confirmed the myocarditis, with the presence of septal and anterior intramyocardial edema in T2 weighted sequences, with prolonged T2 time at T2 mapping analysis, without late gadolinium enhancement areas. Cardiological and general clinical conditions gradually improved only after the antivenom was administred. This is one of the rare cases of viper bite myocarditis with echocardiographic and magnetic resonance imaging documentation in Europe; it emphasizes the importance of identifying uncommon complications of venomous snake-bites and the prompt administration of antivenom, even though snake bites are less frequent at our latitudes.

Isolation and Pharmacological Characterisation of Pre-Synaptic Neurotoxins from Thai and Javanese Russell's Viper (Daboia siamensis) Venoms.

The widespread geographical distribution of Russell's vipers (Daboia spp.) is associated with marked variations in the clinical outcomes of envenoming by species from different countries. This is likely to be due to differences in the quantity and potency of key toxins and, potentially, the presence or absence of some toxins in venoms across the geographical spectrum. In this study, we aimed to isolate and pharmacologically characterise the major neurotoxic components of D. siamensis venoms from Thailand and Java (Indonesia) and explore the efficacy of antivenom and a PLA2 inhibitor, Varespladib, against the neuromuscular activity. These data will provide insights into the link between venom components and likely clinical outcomes, as well as potential treatment strategies. Venoms were fractionated using RP-HPLC and the in vitro activity of isolated toxins assessed using the chick biventer cervicis nerve-muscle preparation. Two major PLA2 fractions (i.e., fractions 8 and 10) were isolated from each venom. Fraction 8 from both venoms produced pre-synaptic neurotoxicity and myotoxicity, whereas fraction 10 from both venoms was weakly neurotoxic. The removal of the two fractions from each venom abolished the in vitro neurotoxicity, and partially abolished myotoxicity, of the whole venom. A combination of the two fractions from each venom produced neurotoxic activity that was equivalent to the respective whole venom (10 µg/mL), but the myotoxic effects were not additive. The in vitro neurotoxicity of fraction 8 (100 nM) from each venom was prevented by the pre-administration of Thai Russell's viper monovalent antivenom (2× recommended concentration) or preincubation with Varespladib (100 nM). Additionally, the neurotoxicity produced by a combination of the two fractions was partially reversed by the addition of Varespladib (100-300 nM) 60 min after the fractions. The present study demonstrates that the in vitro skeletal muscle effects of Thai and Javanese D. siamensis venoms are primarily due to key PLA2 toxins in each venom.

A case of Western Gaboon viper (Bitis rhinoceros) envenomation: Successful treatment with South African Institute for Medical Research (SAIMR) antivenom after North American crotalid antivenom failure.

We report a case of Western Gaboon viper (Bitis rhinoceros) envenomation in which the patient's symptoms progressed despite treatment with North American crotalid antivenom but improved after receiving South African Institute for Medical Research (SAIMR) polyvalent antivenom. A 59-year-old man was hospitalized after reportedly being bitten by a Gaboon viper (Bitis gabonica). On arrival, he had normal vital signs, two puncture wounds on his left hand, and edema distal to the wrist. The hospital contacted the local poison center who conveyed that crotalid antivenom would be ineffective and recommended transfer to a snakebite center for species-appropriate antivenom. However, this recommendation was disregarded. Initial laboratory tests 2 hours after envenomation revealed a platelet count of 77 x 109/L; other parameters were normal. He received six vials of crotalid antivenom (CroFab®) followed by three maintenance doses (total 12 vials). The next morning, swelling had progressed proximal to the elbow and platelets decreased to 37 x 109/L. He was subsequently transferred and received SAIMR polyvalent antivenom. Six hours later, his platelets were 130 x 109/L. The next morning, his swelling had significantly improved. He was discharged the following day. After discharge, it was discovered that the snake was a Bitis rhinoceros. Bitis gabonica and Bitis rhinoceros are popular captive snakes in the United States. Bitis rhinoceros was formerly a sub-species of B. gabonica, and they are often referred to interchangeably. Their venoms cause tissue edema, coagulopathy, and in severe cases, hemorrhage, dysrhythmias, and death. Antivenom is not widely available in the United States often necessitating patient transfer or antivenom delivery. This case addresses the question of whether crotalid antivenom, which is ubiquitous in the United States, can treat B. gabonica and B. rhinoceros envenomations and highlights the need for consultation with a poison center to facilitate administration of species-appropriate antivenom.

Modulation of αv integrins by lebecetin, a viper venom-derived molecule, in experimental neuroinflammation and demyelination models.

Several neurodegenerative diseases, such as multiple sclerosis and Parkinson's disease, are linked to alterations in myelin content or structure. Transmembrane receptors such as integrins could be involved in these alterations. In the present study, we investigated the role of αv-integrins in experimental models of neuroinflammation and demyelination with the use of lebecetin (LCT), a C-lectin protein purified from Macrovipera lebetina viper venom, as an αv-integrin modulator. In a model of neuroinflammation, LCT inhibited the upregulation of αv, ß3, ß5, α5, and ß1 integrins, as well as the associated release of pro-inflammatory factor IL-6 and chemokine CXCL-10, and decreased the expression of phosphorylated NfκB. The subsequent "indirect culture" between reactive astrocytes and oligodendrocytes showed a down-regulation of αv and ß3 integrins versus upregulation of ß1 one, accompanied by a reduced expression of myelin basic protein (MBP). Treatment of oligodendrocytes with LCT rectified the changes in integrin and MBP expression. Through Western blot quantification, LCT was shown to upregulate the expression levels of PI3K and p-mTOR while downregulating expression levels of p-AKT in oligodendrocytes, suggesting the neuroprotective and pro-myelinating effects of LCT may be related to the PI3K/mTor/AKT pathway. Concomitantly, we found that LCT promoted remyelination by tracking the increased expression of MBP in the brains of cuprizone-intoxicated mice. These results point to an involvement of integrins in not only neuroinflammation but demyelination as well. Thus, targeting αv integrins could offer potential therapeutic avenues for the treatment of demyelinating diseases.

Proteomic diversity of Russell's viper venom: exploring PLA2 isoforms, pharmacological effects, and inhibitory approaches.

Snakebite envenomation is a serious health concern in tropical regions, resulting in high mortality. The World Health Organization (WHO) has declared it a neglected tropical disease and is working on strategies to reduce mortality. Russell's viper (Daboia russelii) is one of the most abundant venomous snakes found across Southeast Asia. Proteomic analysis of Russell's viper venom has demonstrated variation, with phospholipase A2 (PLA2) being the most abundant toxin across geographic boundaries. PLA2, a major constituent of the low-molecular-weight fraction of snake venom, hydrolyses phospholipids at the sn-2 position, releasing arachidonic acid and lysophospholipids. They are reported to cause various pharmacological effects, including hemolysis, anticoagulation, neurotoxicity, myotoxicity, and oedema. Though administration of antivenoms (ASV) is the primary treatment for envenomation, it has many drawbacks. Besides causing hypersensitivity reactions and life-threatening anaphylaxis, treatment with ASV is further complicated due to its inability to neutralize low-molecular-weight toxins. Thus, there is a greater need to produce next-generation antivenoms that can target specific toxins in the venom. In this review, we explored the classification of Russell's viper and the variation in its proteomic profile across Southeast Asia to date. In addition, we have also summarized the mechanism of action of PLA2 and discussed various isoforms of PLA2 found across different regions with their respective pharmacological effects. Finally, the drawbacks of commercially available antivenoms and the molecules investigated for inhibiting the low-molecular-weight toxin, PLA2 are discussed.

Importance of the Cysteine-Rich Domain of Snake Venom Prothrombin Activators: Insights Gained from Synthetic Neutralizing Antibodies.

Snake venoms are cocktails of biologically active molecules that have evolved to immobilize prey, but can also induce a severe pathology in humans that are bitten. While animal-derived polyclonal antivenoms are the primary treatment for snakebites, they often have limitations in efficacy and can cause severe adverse side effects. Building on recent efforts to develop improved antivenoms, notably through monoclonal antibodies, requires a comprehensive understanding of venom toxins. Among these toxins, snake venom metalloproteinases (SVMPs) play a pivotal role, particularly in viper envenomation, causing tissue damage, hemorrhage and coagulation disruption. One of the current challenges in the development of neutralizing monoclonal antibodies against SVMPs is the large size of the protein and the lack of existing knowledge of neutralizing epitopes. Here, we screened a synthetic human antibody library to isolate monoclonal antibodies against an SVMP from saw-scaled viper (genus Echis) venom. Upon characterization, several antibodies were identified that effectively blocked SVMP-mediated prothrombin activation. Cryo-electron microscopy revealed the structural basis of antibody-mediated neutralization, pinpointing the non-catalytic cysteine-rich domain of SVMPs as a crucial target. These findings emphasize the importance of understanding the molecular mechanisms of SVMPs to counter their toxic effects, thus advancing the development of more effective antivenoms.

A Randomized Controlled Trial to Optimize Antivenom Therapy for Carpet Viper (Echis romani)-Envenomed Children in Nigeria.

In an open randomized controlled trial, we compared one vial (10 mL) to two vials (20 mL) of EchiTAb-plus-ICP (EPI) antivenom among children with systemic carpet viper (Echis romani) envenoming of moderate severity in northeastern Nigeria. Systemic envenoming, presenting with incoagulable blood, was diagnosed using the 20-minute whole blood clotting test (20WBCT). Eligible patients with positive 20WBCT whose guardians assented were recruited and randomly allocated to receive either one vial or two vials of EPI administered either as a bolus or as a slow continuous infusion. The primary outcome was permanent restoration of blood coagulability 6 hours after the start of treatment, assessed by the 20WBCT and repeated at 6, 12, 24, and 48 hours after treatment. Secondary outcomes were the incidences of early adverse reactions to antivenom treatment. Initial doses permanently restored blood coagulability at 6 hours in 34/39 (87.2%) of those treated with one vial and 39/41 (95.1%) of those treated with two vials of EPI (P = 0.258). However, the proportion with permanent restoration of clotting at 6 hours among patients randomized to bolus administration was 41 of 42 (97.6%) patients compared with 32 of 38 (84.2%) patients randomized to slow infusion of EPI antivenom (P = 0.049); however, the difference was not sustained through the remaining time points. There was no difference in early adverse reactions between those treated with the two different doses or modes of delivery. We conclude that the one-vial dose compared favorably to two vials of EPI antivenom with regards to effectiveness and safety among children with carpet viper envenoming of moderate severity in Nigeria.

Proteomic Analysis and Immunoprofiling of Persian Horned Viper Venom, Pseudocerastes Persicus, from Central Part of Iran.

Numerous species of venomous snakes of medical importance exist in Iran. Pseudocerastes persicus (P. persicus), one of the medically important snakes, also called the Persian horned viper, has a geographical spread that extends to the east, southwest, and central areas of Iran and is endemic across the wider region. As a result, this species is responsible for many snakebite occurrences. Venom from P. persicus found in the central province of Semnan contains phospholipase A2 and L-amino acid oxidase activities, and high toxic potency. The venom was fractionated by reverse-phase high-performance liquid chromatography (HPLC) and analyzed by Sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE), Western blotting and two-dimensional electrophoresis. Using liquid chromatography with tandem mass spectrometry (LC-MS/MS), a range of components were identified, consistent with the biochemical and toxicological properties of the venom. Proteins identified from 2D electrophoresis and shotgun methods included metallo- and serine proteases, phospholipases, oxidases, and Kunitz trypsin inhibitors, along with many other components at lower qualitative abundance. This study provides a more detailed understanding of the protein profile of Iranian P. persicus venom, which can be effective in the production of an effective antidote against it. The analysis of the resulting data shows that there is a wide range of proteins in the venom of the Persian horned viper. This information can provide a better understanding of how venom is neutralized by polyclonal antivenom. Considering the wide presence of this snake and its related species in Iran and surrounding countries, knowing the venom protein profile of this family can be of great support to antivenom producers such as Razi Vaccine & Serum Research Institute in the preparation of regional antivenoms.

Nanofractionation Analytics for Comparing MALDI-MS and ESI-MS Data of Viperidae Snake Venom Toxins.

Worldwide, it is estimated that there are 1.8 to 2.7 million cases of envenoming caused by snakebites. Snake venom is a complex mixture of protein toxins, lipids, small molecules, and salts, with the proteins typically responsible for causing pathology in snakebite victims. For their chemical characterization and identification, analytical methods are required. Reversed-phase liquid chromatography coupled with electrospray ionization mass spectrometry (RP-LC-ESI-MS) is a widely used technique due to its ease of use, sensitivity, and ability to be directly coupled after LC separation. This method allows for the efficient separation of complex mixtures and sensitive detection of analytes. On the other hand, matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS) is also sometimes used, and though it typically requires additional sample preparation steps, it offers desirable suitability for the analysis of larger biomolecules. In this study, seven medically important viperid snake venoms were separated into their respective venom toxins and measured by ESI-MS. In parallel, using nanofractionation analytics, post-column high-resolution fractionation was used to collect the eluting toxins for further processing for MALDI-MS analysis. Our comparative results showed that the deconvoluted snake venom toxin masses were observed with good sensitivity from both ESI-MS and MALDI-MS approaches and presented overlap in the toxin masses recovered (between 25% and 57%, depending on the venom analyzed). The mass range of the toxins detected in high abundance was between 4 and 28 kDa. In total, 39 masses were found in both the ESI-MS and/or MALDI-MS analyses, with most being between 5 and 9 kDa (46%), 13 and 15 kDa (38%), and 24 and 28 kDa (13%) in size. Next to the post-column MS analyses, additional coagulation bioassaying was performed to demonstrate the parallel post-column assessment of venom activity in the workflow. Most nanofractionated venoms exhibited anticoagulant activity, with three venoms additionally exhibiting toxins with clear procoagulant activity (Bothrops asper, Crotalus atrox, and Daboia russelii) observed post-column. The results of this study highlight the complementarity of ESI-MS and MALDI-MS approaches for characterizing snake venom toxins and provide a complementary overview of defined toxin masses found in a diversity of viper snake venoms.

Paraspecific neutralization capacity of polyvalent snake antivenom against Montivipera wagneri venom.

PURPOSE: This study aims to measure the paraspecific neutralization capacity of nationally produced HSGM polyvalent snake antivenom (HSGM-PSAV), produced using Macrovipera lebetina obtusa, Montivipera xanthina, and Vipera ammodytes montandoni venom, against the lethal effect of the venom of Montivipera wagneri, which is endemic to the Eastern Black Sea and Eastern Anatolia regions of Turkey. METHODS: The neutralization capacity of HSGM-PSAV against the lethal effect of M. wagneri venom was studied using the potency determination testing method specified in the Turkish and European Pharmacopoeia. Lethal dose 50 (LD50) values of the venoms used in immunization, M. wagneri venom in mice, and effective dose 50 (ED50) values of HSGM-PSAV against four types of venoms were calculated using two-fold dilutions. RESULTS: HSGM-PSAV neutralized the lethal effect of M. wagneri venom in mice. The ED50 of the HSGM-PSAV against M. wagneri venom was calculated as 304.42 LD50/mL. CONCLUSION: As a result of this in-vivo study, it was determined that HSGM-PSAV neutralized M.wagneri venom above the antivenom neutralization capacity threshold values (≥50 LD50/mL) specified in the Turkish and European Pharmacopoeia. This result is important preclinical data regarding the usability of HSGM-PSAV in the treatment of poisoning due to M. wagneri bites.

Echis ocellatus venom-induced sperm functional deficits, pro-apoptotic and inflammatory activities in male reproductive organs in rats: antagonistic role of kaempferol.

BACKGROUND: Echis ocellatus envenoming is potentially toxic initiating clinical damages on male reproductive system. Kaempferol is a therapeutic agent with neutralizing potentials on snake venom toxins. This study investigated the antagonistic effect of kaempferol on E. ocellatus venom (EoV)-induced reproductive toxicities. METHODS: Fifty adult male rats were sorted at random into five groups of ten rats for this study. The control rats were allotted to group 1, while rats in groups 2-5 were injected with 0.22 mg/kg bw (LD50) of EoV intraperitoneally. Rats in group 2 were not treated while groups 3-5 rats were treated with serum antivenom (0.2 ml), and 4 and 8 mg/kg bw of kaempferol post envenoming, respectively. RESULTS: EoV actuated reproductive toxicity, significantly decreased sperm parameters, and enhanced inflammatory, oxidative stress, and apoptotic biomarkers in reproductive organs of untreated envenomed rats. However, treatment with kaempferol alleviated the venom-induced reproductive disorders with a dose dependent effect. Kaempferol significantly increased the testicular weight, organo-somatic index, sperm parameters, and normalized the levels of serum luteinizing hormone, testosterone, and follicle stimulating hormone. Kaempferol ameliorated testicular and epididymal oxidative stress as evidenced by significant decrease in malondialdehyde (MDA) levels, enhancement of reduced glutathione (GSH) levels, superoxide dismutase (SOD) and glutathione peroxidase (GPX) activities. The inflammatory biomarkers; nitric oxide (NO) levels and myeloperoxidase activity (MPO), and apoptotic biomarkers; caspase 3 and caspase 9 activities were substantially suppressed in the testis and epididymis of envenomed rats treated with kaempferol. CONCLUSION: Results revealed kaempferol as a potential remedial agent against reproductive toxicity that could manifest post-viper envenoming.

Venomics and Peptidomics of Palearctic Vipers: A Clade-Wide Analysis of Seven Taxa of the Genera Vipera, Montivipera, Macrovipera, and Daboia across Türkiye.

Snake venom variations are a crucial factor to understand the consequences of snakebite envenoming worldwide, and therefore it is important to know about toxin composition alterations between taxa. Palearctic vipers of the genera Vipera, Montivipera, Macrovipera, and Daboia have high medical impacts across the Old World. One hotspot for their occurrence and diversity is Türkiye, located on the border between continents, but many of their venoms remain still understudied. Here, we present the venom compositions of seven Turkish viper taxa. By complementary mass spectrometry-based bottom-up and top-down workflows, the venom profiles were investigated on proteomics and peptidomics level. This study includes the first venom descriptions of Vipera berus barani, Vipera darevskii, Montivipera bulgardaghica albizona, and Montivipera xanthina, as well as the first snake venomics profiles of Turkish Macrovipera lebetinus obtusa, and Daboia palaestinae, including an in-depth reanalysis of M. bulgardaghica bulgardaghica venom. Additionally, we identified the modular consensus sequence pEXW(PZ)1-2P(EI)/(KV)PPLE for bradykinin-potentiating peptides in viper venoms. For better insights into variations and potential impacts of medical significance, the venoms were compared against other Palearctic viper proteomes, including the first genus-wide Montivipera venom comparison. This will help the risk assessment of snakebite envenoming by these vipers and aid in predicting the venoms' pathophysiology and clinical treatments.

From birth to bite: the evolutionary ecology of India's medically most important snake venoms.

BACKGROUND: Snake venoms can exhibit remarkable inter- and intraspecific variation. While diverse ecological and environmental factors are theorised to explain this variation, only a handful of studies have attempted to unravel their precise roles. This knowledge gap not only impedes our understanding of venom evolution but may also have dire consequences on snakebite treatment. To address this shortcoming, we investigated the evolutionary ecology of venoms of Russell's viper (Daboia russelii) and spectacled cobra (Naja naja), India's two clinically most important snakes responsible for an alarming number of human deaths and disabilities. METHODOLOGY: Several individuals (n = 226) of D. russelii and N. naja belonging to multiple clutches (n = 9) and their mothers were maintained in captivity to source ontogenetic stage-specific venoms. Using various in vitro and in vivo assays, we assessed the significance of prey, ontogeny and sex in driving venom composition, function, and potency. RESULTS: Considerable ontogenetic shifts in venom profiles were observed in D. russelii, with the venoms of newborns being many times as potent as juveniles and adults against mammalian (2.3-2.5 ×) and reptilian (2-10 ×) prey. This is the first documentation of the ontogenetic shift in viperine snakes. In stark contrast, N. naja, which shares a biogeographic distribution similar to D. russelii, deployed identical biochemical cocktails across development. Furthermore, the binding kinetics of cobra venom toxins against synthetic target receptors from various prey and predators shed light on the evolutionary arms race. CONCLUSIONS: Our findings, therefore, provide fascinating insights into the roles of ecology and life history traits in shaping snake venoms.