Viper Species Research Articles

Ac-[K-Aib-C(3,9-Acm; 6,12-SSNC(Acm)QENSDK)]4-NH2

Advances in synthetic peptide methodologies have enabled the development of macromolecules mimicking protein properties and have found applications in various fields, particularly in immunology. Furthermore, Sequential Oligopeptide Carriers (SOCn and CPSOC) have been designed as multi-functional core molecules, to which multiple bio-cargos can be anchored, allowing the construction of high molecular weight molecules (>3000 Da) capable of inducing a strong immune response. This study presents the design and synthesis of the Ac-[K-Aib-C(3,9-Acm; 6,12-SSNC(Acm)QENSDK)]4-NH2 peptide conjugate of branched architecture. The peptide epitope S128SNCQENSDK137 belongs to the V. berus basic phospholipase A2, a member of the European viper species’ most lethal protein families. The peptide epitope was synthesized according to the SPPS Fmoc/tBu strategy and characterized by HR-ESI-MS and NMR experiments, while the conjugate was purified by RP-HPLC and characterized by HR-ESI-MS.

Melanism in the Saw-scaled Viper, Echis carinatus (Schneider, 1801) from Sheedvar Island, Persian Gulf, Iran

Melanism in Echis carinatus has been observed on Sheedvar Island in the Persian Gulf. A comparative analysis between melanistic and non-melanistic individuals showed no significant morphological or genetic differences. The evolution of melanism in E. carinatus may serve as camouflage or aid in predator avoidance, similar to other nocturnal viper species. However, a deeper understanding of the ecological role of melanism in nocturnal vertebrates, including E. carinatus, requires further investigation to clarify its broader significance.

Snake Venom : A Bioactive Cocktail and its Therapautic use

From ancient time whenever we face any problem, we came to nature for the solution. Our nature is self renewable, she has solution for every problem, but we have to find the right path to respond more quickly. This review is regarding chemical nature of snake venom and about different life saving drugs extracted from snake venom. Venoms were originated from non poisonous proteins, and with subsequent generations under evolution these proteins become mutated and modified multiple times to develop deadly poison. With every modification venom becomes enriched with new diverse group of compounds. Main constituents of venom is hydrolyses, PLA2, phosphodiesterases, serine proteases and metalloproteases. Snakes use their venom to paralyzed their prey and to digest food, but these components can be used to treat various life threatening disease. Cobra, krait and rattle snakes are most poisionous snakes and their venom contains different enzymes, are classified as neurotoxic, haemotoxic and cytotoxic in nature and these have different impact upon exposure to animal. Neurotoxic venom destroy nervous system, haemotoxic venom leads to the destruction of red blood cells and also interfere with blood clotting factors, whereas cytotoxic venom can cause necrosis and apoptosis. With the discovary of modern techniques, isolation of different proteins and peptides and analysis of their nature are become easier. Most widely used drugs extracted from snake venom are Tirofiban, Eptifibatide, Captopril, enalapril, cobratide and batroxobin ete. The source of tirofiban, captopril, enalapril batroxobin is the venom of different viper species. On the other hand, eptifibatide is extracted from rattle snake and cobratide is from Chinese cobra .

Sexual Dimorphism of the Three Pit Viper Species (<i>Gloydius brevicaudus</i>, <i>G. ussuriensis</i>, <i>G. intermedius</i>) in South Korea

Sexual size dimorphism in snakes is closely related to mating behavior and fecundity selection. It provides important information on animal morphology and evolutionary ecology because it allows us to identify key morphological and functional traits between sexes and infer intraspecific competition. In this study, we measured the morphological characters of 147 individuals of three pit viper species stored in the archive of the National Institute of Biological Resources of the Ministry of Environment and confirmed interspecific differences and sexual size dimorphism of each species. We also identified important characters affecting identification using linear discriminant analysis. The results showed that the three pit viper species differed in body and head morphology, and the number of dorsal scale rows was the most important character for species identification. It was found that female red-tongued pit vipers and short-tailed pit vipers were larger than males of each species, while male Central Asian pit vipers were larger than females. Characters related to tail length and head length were confirmed as important characters for interspecific sex discrimination. We compared characters related to head morphology between sexes to find that red-tongued pit vipers showed differences in most characters, while short-tailed pit vipers and Central Asian pit vipers did not. Therefore, short-tailed pit vipers and Central Asian pit vipers are expected to have strong intraspecific competitive pressure. In future studies, it will be necessary to conduct a detailed research on intraspecific competition of short-tailed pit vipers and Central Asian pit vipers with little morphological differences between sexes by examining resource utilization (e.g., food sources and habitats) and ecological niche.

Study of defensive behavior of a venomous snake as a new approach to understand snakebite

Snakebites affect millions of people worldwide. The majority of research and management about snakebites focus on venom and antivenom, with less attention given to snake ecology. The fundamental factor in snakebites is the snakes’ defensive biting behavior. Herein we examine the effects of environmental variables (temperature, time of day, and human stimulus) and biological variables (sex and body size) on the biting behavior of a medically significant pit viper species in Brazil, Bothrops jararaca (Viperidae), and associate it with the epidemiology of snakebites. Through experimental simulations of encounters between humans and snakes, we obtained behavioral models applicable to epidemiological situations in the State of São Paulo, Brazil. We found a significant overlap between behavioral, morphological, environmental, and epidemiological data. Variables that increase snakebites in epidemiological data also enhance the tendency of snakes to bite defensively, resulting in snakebites. We propose that snakebite incidents are influenced by environmental and morphological factors, affecting the behavior of snakes and the proportion of incidents. Thus, investigating behavior of snakes related to snakebite incidents is a valuable tool for a better understanding of the epidemiology of these events, helping the prediction and, thus, prevention of snakebites.

Vipers in the state of Acre, western Brazilian Amazon: a review

Snakes of the family Viperidae are distributed in many different ecosystems, generally being the most abundant species in snake surveys and studies on snake assemblages in Brazil. These species are medically important as they can cause snakebites and are responsible for approximately 99% of envenomings in humans in Brazil. Considering the ecological importance of snakes in terrestrial ecosystems, mainly as important predators in food webs, and in public health due to the risks of snakebites, here we review the information available in the literature about vipers in the state of Acre, western Brazilian Amazon. Six species of vipers were already recorded for Acre, with Bothrops atrox being the most abundant, present in various types of habitats and being the main species involved in snakebites. Bothrops bilineatus is the most common snake found in a floodplain forest in the protected area Japiim Pentecoste, a factor probably associated with prey availability. The other four species of vipers (Bothrocophias hyoprora, Bothrops brazili, B. taeniatus and Lachesis muta) are less frequent and associated with unflooded forests. Although we found in the literature several studies involving vipers in Acre, there is a need for more studies on these snakes in the region, addressing their ecology, ethno-herpetological questions and snakebites, including research on their ecology and behavior in the field, genetic variation and differentiation among populations and species, and biochemical composition of venoms.

In vitro immunoreactivity and in vivo neutralization of Trimeresurus gracilis venom with antivenoms targeting four pit viper species.

Snakebite envenomation is a significant global health issue that requires specific antivenom treatments. In Taiwan, available antivenoms target a variety of snakes, but none specifically target Trimeresurus gracilis, an endemic and protected species found in the high mountain areas of Taiwan. This study evaluated the effectiveness of existing antivenoms against T. gracilis venom, focusing on a bivalent antivenom developed for Trimeresurus stejnegeri and Protobothrops mucrosquamatus (TsPmAV), as well as monovalent antivenoms for Deinagkistrodon acutus (DaAV) and Gloydius brevicaudus (GbAV). Our research involved in vivo toxicity testing in mice and in vitro immunobinding experiments using (chaotropic) enzyme-linked immunosorbent assays, comparing venoms from four pit viper species (T. gracilis, T. stejnegeri, P. mucrosquamatus, and D. acutus) with three types of antivenoms. These findings indicate that TsPmAV partially neutralized T. gracilis venom, marginally surpassing the efficacy of DaAV. In vitro tests revealed that GbAV displayed higher binding capacities toward T. gracilis venom than TsPmAV or DaAV. Comparisons of electrophoretic profiles also reveal that T. gracilis venom has fewer snake venom C-type lectin like proteins than D. acutus, and has more P-I snake venom metalloproteases or fewer phospholipase A2 than G. brevicaudus, T. stejnegeri, or P. mucrosquamatus. This study highlights the need for antivenoms that specifically target T. gracilis, as current treatments using TsPmAV show limited effectiveness in neutralizing local effects in patients. These findings provide crucial insights into clinical treatment protocols and contribute to the understanding of the evolutionary adaptation of snake venom, aiding in the development of more effective antivenoms for human health.

Viper Venom Phospholipase A2 Database: The Structural and Functional Anatomy of a Primary Toxin in Envenomation.

Viper venom phospholipase A2 enzymes (vvPLA2s) and phospholipase A2-like (PLA2-like) proteins are two of the principal toxins in viper venom that are responsible for the severe myotoxic and neurotoxic effects caused by snakebite envenoming, among other pathologies. As snakebite envenoming is the deadliest neglected tropical disease, a complete understanding of these proteins' properties and their mechanisms of action is urgently needed. Therefore, we created a database comprising information on the holo-form, cofactor-bound 3D structure of 217 vvPLA2 and PLA2-like proteins in their physiologic environment, as well as 79 membrane-bound viper species from 24 genera, which we have made available to the scientific community to accelerate the development of new anti-snakebite drugs. In addition, the analysis of the sequenced, 3D structure of the database proteins reveals essential aspects of the anatomy of the proteins, their toxicity mechanisms, and the conserved binding site areas that may anchor universal interspecific inhibitors. Moreover, it pinpoints hypotheses for the molecular origin of the myotoxicity of the PLA2-like proteins. Altogether, this study provides an understanding of the diversity of these toxins and how they are conserved, and it indicates how to develop broad, interspecies, efficient small-molecule inhibitors to target the toxin's many mechanisms of action.

Snakebite Envenomation From the Large Palearctic Viper, Macrovipera razii (Squamata: Serpentes; Viperidae), in Fars Province, Southern Iran.

Snakebites are a significant health issue, especially in tropical and subtropical regions. Envenomation from snakebites is a clinical emergency requiring prompt treatment. Recently, a new species of blunt-nosed viper, Macrovipera razii, was identified in central and southern Iran through morphological and molecular studies. This large, dangerous viper can deliver substantial amounts of venom. Following reports to the Faculty of Health at Shiraz University of Medical Science (SUMS), the identification of venomous snakes involved in envenomation cases in Fars province was undertaken. Approximately 20 snakes were captured and presented by locals, while others provided photos. Despite some information being photo-based, the data highlighted the significant role of this viper in envenomation cases. Macrovipera razii is now recorded from 12 counties in Fars province. One incident involved a male bitten in Shiraz, and another case led to a male needing limb amputation. This study emphasizes the importance of this newly described viper in recent snakebite envenomations in the region and reviews its distribution within the Fars province.

Systematic review and meta-analysis on the efficacy of Indian polyvalent antivenom against the Indian snakes of clinical significance.

Snakebite in India is a severe problem as it causes a mortality rate of 58,000 and a disability rate of 140,000 every year which is the highest among any other country. Antivenom is the primary therapy for snakebite, and its manufacturing techniques have essentially stayed unaltered for over a century. Indian polyvalent antivenom, a scientifically validated medicine for treating the toxic effects of snakebites, is available against the venom of the so-called Big Four snakes namely Spectacled cobra (Naja naja), Saw-scaled viper (Echis carinatus), Russell's viper (Daboia russelli) and the Common krait (Bungarus caeruleus), responsible for majority of the deaths in India. India hosts many other species of snakes, including cobras, kraits, saw-scaled vipers, sea snakes, and pit vipers, responsible for clinically severe envenomation. Neutralization strategy has been applied to access the efficacy of antivenoms, crucial for reducing snake bite deaths and disabilities. This review aims to conduct a systematic review and meta-analysis on the neutralization efficiency of the Polyvalent Antivenom (PAV) and focus on the factors that may contribute to the poor recognition of the antivenom towards the venom toxins. Reports focusing on the investigation of antivenom efficacy were searched and collected from several databases. Preclinical studies that reported the neutralization efficacy of the commercial antivenom against the medically important snakes of India were included. The articles were screened based on the inclusion criteria and 8 studies were shortlisted for meta-analysis. Pooled proportion was calculated for the antivenom efficacy reported by the studies and was found to be statistically significant with a 95% confidence interval. The heterogenicity in the venom toxicity and neutralization potency of the antivenom was evident in the overall estimate (proportion) and individual data. We provide comprehensive evidence on antivenom efficacy against medically important snakes from various parts of India which may aid in identifying the gaps in snake envenomation therapy and the need for novel potentially improved treatment of snakebites.

Local niches explain coexistence in environmentally-distinct contact zones between Western Mediterranean vipers

Species’ ecological niches are frequently analysed to gain insights into how anthropogenic changes affect biodiversity. Coping with these changes often involves shifts in niche expression, which can disrupt local biotic interactions. Secondary contact zones, where competition and ecological segregation commonly occur, are ideal for studying the ecological factors influencing species’ niches. In this study, we investigated the effect of climate and landscape factors on the ecological niches of two viper species, Vipera aspis and Vipera latastei, across three contact zones in northern Iberia, characterized by varying levels of landscape alteration. Using niche overlap tests, ecological niche models and spatial analyses we observed local variation in the expression of the species’ niches across the three contact zones, resulting from the different abiotic and biotic conditions of each area. Rather than spatial niche segregation, we observed high niche overlap, suggesting niche convergence. A pattern of asymmetrical niche variation was identified in all contact zones, driven by species' climatic tolerances and the environmental conditions of each area. V. aspis generally exhibited a wider niche, except in the southernmost zone where the pure Mediterranean climate favored V. latastei. Human-induced landscape changes intensified niche asymmetry, by favoring the most generalist V. aspis over the specialist V. latastei, increasing habitat overlap, and likely competition. This study presents a comprehensive analysis of niche expression at range margins, anticipating a heightened impact of landscape changes in V. latastei. The methodological framework implemented here, and our findings, hold significant relevance for biodiversity management and conservation in human-impacted areas.

EFFECT OF TEMPERATURE ON THE PROTEIN PROFILE OF MACROVIPERA LEBETINUS (BLUNT-NOSED VIPER) VENOM: A PRELIMINARY STUDY

Snake venom is a complex biological fluid consisting mainly of proteins and peptides possessing diverse biological activities. Snake venoms draw attention due to their bioactive proteins/peptides with therapeutic and diagnostic potential. Testing the stability of snake venom proteins under different conditions including temperature provides useful data for venom research. Macrovipera lebetinus, blunt-nosed viper, is the biggest viper species of Türkiye distributed mainly in eastern and southeastern Anatolia. Although its venom components were investigated before, there is limited data regarding the effect of temperature on its venom proteins. The present study aimed to investigate the effect of temperature on the venom proteins of M. lebetinus. For this purpose, venom samples were incubated at 25, 37, and 50°C. Thereafter, venom proteins were separated by two-dimensional gel electrophoresis (2D-PAGE) method. Some qualitative and quantitative differences in the protein profile indicating structural changes and degradation were observed especially after 50°C treatment. It has been found that the protein spots most affected by temperature will most likely contain metalloproteinase, phospholipase A2 and ʟ-amino acid oxidase enzymes, by comparing the experimental molecular weight and pI values with those in the literature. Detailed studies including enzyme activities and toxicity assays will provide more data on the stability of M. lebetinus venom under different conditions.

Frequency, geographical distribution and outcomes of pit viper bites in Malaysia consulted to Remote Envenomation Consultancy Services (RECS) from 2017 to 2020.

Not all pit viper species are present in every state of Malaysia and their distribution varies according to altitude. There is limited information on pit viper bite incidence and its geographical distribution. This was a cross-sectional study of confirmed pit viper bite cases referred to Remote Envenomation Consultancy Services (RECS) from January 2017 to December 2020. Data was collected following the approval of institutional research ethics committee. Universal sampling methods were used. Confirmed pit viper bite cases in each state, geographical location and the antivenom used were reported. A total of 523 confirmed pit viper bite injuries occurred over the 4-year study period. The majority were Malaysians, male and young adults. Most were non-occupational related (83.9%) and involved the upper limbs (46.8%). The commonest pit viper species involved was Trimeresurus purpureomaculatus (23.7%). Green pit viper antivenom (GPAV) was the most frequent antivenom used (n = 51) with the majority of patients requiring only one dose (3 vials). This study provides a better appreciation of indigenous pit viper species distribution for each state and reflects the requirement of appropriate antivenom to be stocked in each state or district hospital.

The Artefactual Branch Effect and Phylogenetic Conflict: Species Delimitation with Gene Flow in Mangrove Pit Vipers (Trimeresurus purpureomaculatus-erythrurus Complex).

Mangrove pit vipers of the Trimeresurus purpureomaculatus-erythrurus complex are the only species of viper known to naturally inhabit mangroves. Despite serving integral ecological functions in mangrove ecosystems, the evolutionary history, distribution, and species boundaries of mangrove pit vipers remain poorly understood, partly due to overlapping distributions, confusing phenotypic variations, and the lack of focused studies. Here, we present the first genomic study on mangrove pit vipers and introduce a robust hypothesis-driven species delimitation framework that considers gene flow and phylogenetic uncertainty in conjunction with a novel application of a new class of speciation-based delimitation model implemented through the program Delineate. Our results showed that gene flow produced phylogenetic conflict in our focal species and substantiates the artefactual branch effect where highly admixed populations appear as divergent nonmonophyletic lineages arranged in a stepwise manner at the basal position of clades. Despite the confounding effects of gene flow, we were able to obtain unequivocal support for the recognition of a new species based on the intersection and congruence of multiple lines of evidence. This study demonstrates that an integrative hypothesis-driven approach predicated on the consideration of multiple plausible evolutionary histories, population structure/differentiation, gene flow, and the implementation of a speciation-based delimitation model can effectively delimit species in the presence of gene flow and phylogenetic conflict.

Addition of four new records of pit vipers (Squamata: Crotalinae) to Manipur, India

In spite of the potential richness in biodiversity, Manipur is still one of the least explored areas in northeastern India. In this work, we report on our finding of four pit viper species, namely, Trimeresurus mayaae, T. salazar, T. erythrurus, and Protobothrops jerdonii in Manipur during our herpetological surveys in 2022. We affirm the identity of these specimens based on the combination of standard morphological characters and mitochondrial cytochrome b gene. Our study not only reports four new records of pit vipers for the first time in Manipur, but also extends their respective known geographical ranges. This information calls for further dissemination especially to health care sector, as it is on venomous snakes that could be of medical importance as regards human snakebites.

Epidemiology and clinical features of Hypnale nepa (hump-nosed pit viper) envenoming in Sri Lanka

Sri Lanka homes 3 species of hump-nosed pit vipers including Hypnale Hypnale, H. zara and H. nepa from which, latter 2 are endemic to the country. Even though former 2 are the subject of several publications, no major clinical studies have been done regarding H. nepa bites. As these snakes confine only to central hills of the country, their bites are very rare. The objectives of this study were to describe epidemiological and clinical features of H. nepa bites. A prospective observational study was conducted for patients admitted with H. nepa bites to Teaching Hospital, Ratnapura, Sri Lanka for 5 years commencing from June 2015. Species identification was done using a standard key.There were 14 (3.6%) patients with H. nepa bites of which 9 (64%) were males and 5 (36%) were females. Their age ranged from 20 to 73 years (median 37.5). Seven bites (50%) occurred on lower limbs. Majority of bites (10; 71%) happened at daytime [0600–1759 h] in tea estates (8; 57%). Most patients (8; 57%) were admitted within 1–3 h from bite. Hospital stay was 2.5 days (IQR 2–3). Local envenoming was observed in all patients including local pain and swelling [mild (7; 50%), moderate (5; 36%), severe (2; 14%)], local bleeding (1; 7%) and lymphadenopathy (1; 7%). Nonspecific features were observed in 3 (21%). Systemic manifestations were found in 2 (14%) including microangiopathic haemolytic anaemia and sinus bradycardia. Two (14%) had myalgia. H. nepa bites frequently cause local envenoming. But, rarely systemic manifestations may occur.

A study of individual differences in spatial use of captive sidewinder rattlesnakes Crotalus cerastes

Many species of vipers are known to use ambush sites repeatedly, a phenomenon presumably informed by chemical cues from prey. Experimentally, we limited chemical cue availability and recorded site selection in five captive-born sidewinders Crotalus cerastes during their first active season. Snakes showed individual differences among the study subjects in spatial movement across the season and repeatedly reused specific sites in their enclosures, suggesting spatial memory and individual differences in choices of resting sites. Individual variability in spatial- and object-use and associated memories suggests attention to such should be considered in developing husbandry routines for these captive individuals.

In silico Screening of the Potential Anti-SARS-CoV-2 Activities of Peptides from Vipera ammodytes ammodytes Venom by Molecular Docking

The coronavirus disease 2019 (COVID-19) is induced by the SARS-CoV-2 virus, which caused the global pandemic, infecting approximately 608.328.548 confirmed cases and bringing about 6.501.469 deaths worldwide, as WHO stated in September 2022. The disease is more deadly due to the lack of specific drug molecules or a treatment plan. Therefore, the development of potent pharmacological compounds is urgently required to combat COVID-19. Due to their biological actions, snake venoms constitute a source of potentially beneficial medicinal compounds. Vipera ammodytes ammodytes (VA) is a viper species whose venom has been shown to have anti-proliferative, antimetastatic, anti-cancer, and anti-microbial activities. This in silico study was conducted to evaluate the efficacy of selected VA venom proteins (Adamalysin II, Ammodytoxin A, Ammodytin L, L-amino acid oxidase) against molecular targets; Main protease (3CLpro) and Angiotensin-Converting Enzyme 2 (ACE2) by molecular docking study. Molecular docking investigations were performed by using AutoDock Vina software. All compounds displayed negative binding energy values to 3CLpro and ACE2, suggesting that their interactions with the active sites were favourable. L-amino acid oxidase had the highest binding affinity with both 3CLpro and ACE2. This study revealed for the first time that VA venom proteins are functional inhibitors of 3CLpro and ACE2 activities, and the components of VA venom can be considered potential SARS-CoV-2 inhibitors. However, more studies are needed to validate these compounds in vitro and in vivo.

Fangs in the Ghats: Preclinical Insights into the Medical Importance of Pit Vipers from the Western Ghats.

The socioeconomic impact of snakebites in India is largely attributed to a subset of snake species commonly known as the 'big four'. However, envenoming by a range of other clinically important yet neglected snakes, a.k.a. the 'neglected many', also adds to this burden. The current approach of treating bites from these snakes with the 'big four' polyvalent antivenom is ineffective. While the medical significance of various species of cobras, saw-scaled vipers, and kraits is well-established, the clinical impact of pit vipers from regions such as the Western Ghats, northeastern India, and the Andaman and Nicobar Islands remains poorly understood. Amongst the many species of snakes found in the Western Ghats, the hump-nosed (Hypnale hypnale), Malabar (Craspedocephalus malabaricus), and bamboo (Craspedocephalus gramineus) pit vipers can potentially inflict severe envenoming. To evaluate the severity of toxicity inflicted by these snakes, we characterised their venom composition, biochemical and pharmacological activities, and toxicity- and morbidity-inducing potentials, including their ability to damage kidneys. Our findings highlight the therapeutic inadequacies of the Indian and Sri Lankan polyvalent antivenoms in neutralising the local and systemic toxicity resulting from pit viper envenomings.

High-throughput proteomics and in vitro functional characterization of the 26 medically most important elapids and vipers from sub-Saharan Africa.

Venomous snakes are important parts of the ecosystem, and their behavior and evolution have been shaped by their surrounding environments over the eons. This is reflected in their venoms, which are typically highly adapted for their biological niche, including their diet and defense mechanisms for deterring predators. Sub-Saharan Africa is rich in venomous snake species, of which many are dangerous to humans due to the high toxicity of their venoms and their ability to effectively deliver large amounts of venom into their victims via their bite. In this study, the venoms of 26 of sub-Saharan Africa's medically most relevant elapid and viper species were subjected to parallelized toxicovenomics analysis. The analysis included venom proteomics and in vitro functional characterization of whole venom toxicities, enabling a robust comparison of venom profiles between species. The data presented here corroborate previous studies and provide biochemical details for the clinical manifestations observed in envenomings by the 26 snake species. Moreover, two new venom proteomes (Naja anchietae and Echis leucogaster) are presented here for the first time. Combined, the presented data can help shine light on snake venom evolutionary trends and possibly be used to further improve or develop novel antivenoms.