Biochemical and biological study and characterization of the venom of juvenile and adult snakes of the species Bothrops moojeni.

O estudo dos venenos de serpentes é uma importante área da pesquisa biomédica em virtude de suas ações neurotóxicas, hemorrágicas e proteolíticas. O gênero Bothrops é considerado um dos mais importantes no Brasil pela alta incidência de acidentes ofídicos. São descritas três atividades fisiopatológicas do veneno botrópico: proteolítica, coagulante e hemorrágica. O veneno de serpentes está sujeito às variações intraespecíficas, que, por sua vez, sofrem influência de distribuição geográfica, sexo, idade (ontogenia), cativeiro, etc. Existem descrições sobre a ontogenia de alguns venenos de serpentes, porém, estudos comparativos referentes às atividades bioquímicas e biológicas de espécimes adultos e jovens de algumas espécies, como a B. moojeni, não foram completamente elucidados. Com isso, o presente estudo teve como objetivo caracterizar e comparar, bioquímica e biologicamente, a influência da ontogenia e do sexo no veneno da serpente B. moojeni. Comparando esses parâmetros, os venenos apresentaram diferenças bastante evidentes quanto à composição, e, principalmente, quanto às atividades proteolítica e coagulante. Os venenos de serpentes mais jovens são mais coagulantes, enquanto os de adultos são mais proteolíticos; já em relação ao sexo, os venenos de fêmeas se mostraram mais proteolíticos do que os de machos, que, em contrapartida, são mais coagulantes. Apesar deste contraste, a letalidade dos venenos de neonatos e de adultos não apresentou diferença estatística, mas o veneno de adultos apresentou ação mais rápida sobre os animais. Além disso, o imunorreconhecimento pelo soro antibotrópico foi bastante similar entre os venenos analisados. Estes resultados sugerem que, apesar das variações observadas, a letalidade não se altera, talvez devido ao sinergismo das proteínas, e o bom imunorreconhecimento pode indicar uma boa resposta do soro antibotrópico no tratamento dos acidentes ofidicos causados pela B. moojeni.The study of snake venoms is an important area of biomedical research for its neurotoxic, hemorrhagic and proteolytic effects. Bothrops is one of the most important genera in Brazil due to the high incidence of snake bites. Three physiopathological activities are described for the bothropic venom: proteolytic, procoagulant and hemorrhagic. Snake venom is susceptible to intraspecific variations that are related to geographic distribution, sex, age (ontogeny), captivity, etc. Although described for many species, studies regarding comparison of the biochemical and biological features between adult and juvenile snake venoms are not completely elucidated for some species, like B. moojeni. Thereby, the present study aimed to characterize and compare, biochemically and biologically, the influence of ontogeny and sex on the snake venom of B. moojeni. Analyzing these parameters, some differences were quite marking in the venom composition and, especially, concerning proteolytic and procoagulant activities. The venom of younger snakes are showed higher coagulant activity, while adults were more proteolytic; in relation to sex, female venoms were more proteolytic than male, which were more coagulant instead. Despite these differences, the lethality did not show statistical difference, although adult venom acted faster than neonate venom. Besides, immunorecognition of the venom by antibothropic serum was very similar among the venoms. These results suggest that lethality of the venom does not vary according to age, so it might be related to the sinergism of the proteins in it, and the immunorecognition can indicate a possible good response to the treatment with antibothropic serum of snake bites caused by B. moojeni

Proteomics and life-history variability of Endogenous Phospholipases A2 Inhibitors (PLIs) in Bothrops jararaca plasma.

In Brazil, the genus Bothrops is responsible for most ophidian accidents. Snake venoms have a wide variety of proteins and peptides exhibiting a broad repertoire of pharmacological and toxic effects that elicit systemic injury and characteristic local effects. The snakes' natural resistance to envenomation caused by the presence of inhibitory compounds on their plasma have been extensively studied. However, the presence of these inhibitors in different developmental stages is yet to be further discussed. The aim of this study was to evaluate the ontogeny of Bothrops jararaca plasma inhibitor composition and, to this end, plasma samples of B. jararaca were obtained from different developmental stages (neonates, youngs, and adults) and sexes (female and male). SDS-PAGE, Western blotting, affinity chromatography, and mass spectrometry were performed to analyze the protein profile and interaction between B. jararaca plasma and venom proteins. In addition, the presence of γBjPLI, a PLA2 inhibitor previously identified and characterized in B. jararaca serum, was confirmed by Western blotting. According to our results, 9-17% of plasma proteins were capable of binding to venom proteins in the three developmental stages. The presence of different endogenous inhibitors and, more specifically, different PLA2 inhibitor (PLI) classes and antihemorrhagic factors were confirmed in specimens of B. jararaca from newborn by mass spectrometry. For the first time, the αPLI and βPLI were detected in B. jararaca plasma, although low or no ontogenetic and sexual correlation were found. The γPLI were more abundant in adult female, than in neonate and young female, but similar to neonate, young and adult male according to the results of mass spectrometry analysis. Our results suggest that there are proteins in the plasma of these animals that can help counteract the effects of self-envenomation from birth