Coral snakes of the genus Micrurus have a high diversity and a wide distribution in the Americas. Despite envenomings by these animals are uncommon, accidents are often severe and may result in death. Producing an antivenom to treat these envenomings has been challenging since coral snakes are difficult to catch, produce small amounts of venom, and the antivenoms produced have shown limited cross neutralization. Here we present data of cross neutralization among monovalent antivenoms raised against M. dumerilii, M. isozonus, M. mipartitus and M. surinamensis and the development of a new polyvalent coral snake antivenom, resulting from the mix of monovalent antivenoms. Our results, show that this coral snake antivenom has high neutralizing potency and wide taxonomic coverage, constituting a possible alternative for a long sought Pan-American coral snake antivenom. Coral snakes are distributed in the Americas form Southern United States to Argentina. These snakes cause envenomings that, despite not being common, often lead to death. The antivenoms currently produced to treat accidents caused by these snakes have limitations regarding the number of species venoms they could neutralize. Here, we present an antivenom with a wide spectrum of neutralization, when compared to other Anticoral antivenoms. Nevertheless, more studies are still necessary to evaluate its neutralization capacity against the venoms of other species. This antivenom has great potential, as it neutralizes the lethal effects of some of the most common Micrurus species in the Americas.

Little is known of the biochemical composition and functional features of the venoms of poorly known Colombian coral snakes. Here, we provide a preliminary characterization of the venom of two Colombian endemic coral snake species, Micrurus medemi and M. sangilensis, as well as Colombian populations of M. helleri. Electrophoresis and RP-HPLC techniques were used to identify venom components, and assays were conducted to detect enzyme activities, including phospholipase A₂, hyaluronidase, and protease activities. The median lethal dose was determined using murine models. Cytotoxic activities in primary cultures from hippocampal neurons and cancer cell lines were evaluated. The venom profiles revealed similarities in electrophoretic separation among proteins under 20 kDa. The differences in chromatographic profiles were significant, mainly between the fractions containing medium-/large-sized and hydrophobic proteins; this was corroborated by a proteomic analysis which showed the expected composition of neurotoxins from the PLA₂ (~38%) and 3FTx (~17%) families; however, a considerable quantity of metalloproteinases (~12%) was detected. PLA₂ activity and protease activity were higher in M. helleri venom according to qualitative and quantitative assays. M. medemi venom had the highest lethality. All venoms decreased cell viability when tested on tumoral cell cultures, and M. helleri venom had the highest activity in neuronal primary culture. These preliminary studies shed light on the venoms of understudied coral snakes and broaden the range of sources that could be used for subsequent investigations of components with applications to specific diseases. Our findings also have implications for the clinical manifestations of snake envenoming and improvements in its medical management.

Biochemical and biological differences in the venom of Crotalus durissus cumanensis from three ecoregions of Colombia were evaluated. Rattlesnakes were collected from the geographic areas of Magdalena Medio (MM), Caribe (CA) and Orinoquía (OR). All three regionally distributed venoms contain proteases, PLA₂s and the basic subunit of crotoxin. However, only crotamine was detected in the CA venom. The highest lethality, coagulant, phospholipase A₂ and hyaluronidase activities were found in the MM venom. Also, some differences, observed by western blot and immunoaffinity, were found in all three venoms when using commercial antivenoms. Furthermore, all three eco-regional venoms showed intraspecific variability, considering the differences in the abundance and intensity of their components, in addition to the activity and response to commercial antivenoms.

Snakebite accident treatment requires the administration of antivenoms that provide efficacy and effectiveness against several snake venoms of the same genus or family. The low number of immunogenic components in venom mixtures that allow the production of antivenoms consequently gives them partial neutralization and a suboptimal pharmacological response. This study evaluates the immunorecognition and neutralizing efficacy of the polyvalent anticoral antivenom from the Instituto Nacional de Salud (INS) of Colombia against the heterologous endemic venoms of Micrurus medemi, and M. sangilensis, and M. helleri by assessing immunoreactivity through affinity chromatography, ELISA, Western blot, and neutralization capability. Immunorecognition towards the venoms of M. medemi and M. sangilensis showed values of 62% and 68% of the protein composition according to the immunoaffinity matrix, respectively. The analysis by Western blot depicted the highest recognition patterns for M. medemi, followed by M. sangilensis, and finally by M. helleri. These findings suggest that the venom compositions are closely related and exhibit similar recognition by the antivenom. According to enzyme immunoassays, M. helleri requires a higher amount of antivenom to achieve recognition than the others. Besides reinforcing the evaluation of INS antivenom capability, this work recommends the use of M. helleri in the production of Colombian antisera.

Introduction: The results of administering recombinant leptin, as well as the 116-130 peptide of mouse leptin in ob/ob mice have shown the probability of discovering more efficient leptin-based therapeutic methods to treat obesity. Objective: To demonstrate in Wistar rats fed with high-fat diet if the administration of synthetic peptides corresponding to the 116-130 peptide of mouse leptin (SR 116), its human homologue peptide (SH 95: sequence 95-109 from the 1AX8 protein) and five modified peptides (P80 to P84) similar to these two peptides, produces effects related to regulation of body fat. Materials and methods: Nine-week old Wistar rats were fed a high-fat diet for fifteen weeks. On the fifteenth week, and for five consecutive days, they were treated with the peptides to be evaluated. During the days of treatment, body weight and food intake were evaluated. After the last peptide administration, lipid profile, glycerol in the cellular medium, and DNA fragmentation in adipocytes were analyzed. Results: The results revealed that: the SR116 peptide affects the regulation of adiposity in rats fed a high-fat diet. The SH 95 is the human peptide with biological activity similar to SR 116 to lower weight, lessen food intake, and increase free glycerol in the cellular medium. The P80 and P81 peptides had a similar effect on SR 116 and SH 95 regarding body weight and food intake. The SR 116, SH 95 and three of the modified peptides (P80, P81, and P82) caused DNA fragmentation. Conclusion: The results suggest that peptides analogous to leptin are potentially viable to achieve effects of adiposity reduction in Wistar rats with obesity associated to high-fat diet; more research is rendered to explain the differences among peptides and the biological action mechanisms.

The keyto establishing a large-scale program for the production of snake antivenom is to maintain alive the largest number of medically important snakes in an intensive captive environment. However, captivity is associated with stressors that can provoke chronic, steady physiological and behavioral changes in snakes, causing responses from non-adaptive levels of glucocorticoid secretion that lead to impaired welfare of the captive snakes in a serpentarium. Understanding the pathologies and their impacts on the general population of the serpentarium, as well as learning the best practices to maintain them in captivity, are the main goals for achieving a program for antivenom production. Nevertheless, gaining understanding and learning from lessons is a long trail in which empirical approaches, common sense, and the experience of elders are the best guide. This chapter summarizes and analyzes the historical data available from 1990 to 2021 from the captive snakes employed for antivenom production housed in the serpentarium of the Colombian National Health Institute. Additionally, we provide a brief history of learned lessons about the venomous snakes housed in the serpentarium, as well as the most interesting information about them.