Analgesic Effect of Photobiomodulation on Bothrops Moojeni Venom-Induced Hyperalgesia: A Mechanism Dependent on Neuronal Inhibition, Cytokines and Kinin Receptors Modulation.

BACKGROUND: Envenoming induced by Bothrops snakebites is characterized by drastic local tissue damage that involves an intense inflammatory reaction and local hyperalgesia which are not neutralized by conventional antivenom treatment. Herein, the effectiveness of photobiomodulation to reduce inflammatory hyperalgesia induced by Bothrops moojeni venom (Bmv), as well as the mechanisms involved was investigated. METHODOLOGY/PRINCIPAL FINDINGS: Bmv (1 µg) was injected through the intraplantar route in the right hind paw of mice. Mechanical hyperalgesia and allodynia were evaluated by von Frey filaments at different time points after venom injection. Low level laser therapy (LLLT) was applied at the site of Bmv injection at wavelength of red 685 nm with energy density of 2.2 J/cm2 at 30 min and 3 h after venom inoculation. Neuronal activation in the dorsal horn spinal cord was determined by immunohistochemistry of Fos protein and the mRNA expression of IL-6, TNF-α, IL-10, B1 and B2 kinin receptors were evaluated by Real time-PCR 6 h after venom injection. Photobiomodulation reversed Bmv-induced mechanical hyperalgesia and allodynia and decreased Fos expression, induced by Bmv as well as the mRNA levels of IL-6, TNF-α and B1 and B2 kinin receptors. Finally, an increase on IL-10, was observed following LLLT. CONCLUSION/SIGNIFICANCE: These data demonstrate that LLLT interferes with mechanisms involved in nociception and hyperalgesia and modulates Bmv-induced nociceptive signal. The use of photobiomodulation in reducing local pain induced by Bothropic venoms should be considered as a novel therapeutic tool for the treatment of local symptoms induced after bothropic snakebites.

Fatal neurotoxic envenomation following the bite of a greater black krait (Bungarus niger) in Nepal: a case report

Neurotoxic envenomation following bites by kraits (Bungarus species) is a leading cause of snakebite mortality in South Asia. Over a long time, this had been attributed only to one species, the common krait (Bungarus caeruleus). However, recent research has provided increasing evidence of the involvement of several krait species. Here, we report a fatal case of neurotoxic envenomation following the bite of a greater black krait (Bungarus niger) in Nepal. Case presentation A 33-year-old man was bitten in the outdoor corridor of his home in the eastern hills of Ilam district while handling a snake he thought to be non-venomous. He subsequently developed severe abdominal pain, frequent vomiting, and signs of neurotoxic envenomation leading to respiratory paralysis. The patient did not respond to Indian polyvalent antivenom given 4 h after the bite and died under treatment 8 h after the bite. This is the second time that a B. niger was observed in Nepal, the first documented case of envenomation by this species in the country and the sixth reported case worldwide. Conclusions Previous distribution records from eastern India and western Nepal, from western hills in Nepal, and from lowland localities in India and Bangladesh indicate risk of envenomation by B. niger throughout the low and intermediate elevations of Nepal up to at least 1,500 m above sea level. As very few people in Nepal bring killed snakes to healthcare centers and because there is a general belief among local people that there are no kraits in the hills, bites by B. niger are likely to be misdiagnosed and underreported.(AU)

Fatal neurotoxic envenomation following the bite of a greater black krait (Bungarus niger) in Nepal: a case report

Neurotoxic envenomation following bites by kraits (Bungarus species) is a leading cause of snakebite mortality in South Asia. Over a long time, this had been attributed only to one species, the common krait (Bungarus caeruleus). However, recent research has provided increasing evidence of the involvement of several krait species. Here, we report a fatal case of neurotoxic envenomation following the bite of a greater black krait (Bungarus niger) in Nepal. Case presentation A 33-year-old man was bitten in the outdoor corridor of his home in the eastern hills of Ilam district while handling a snake he thought to be non-venomous. He subsequently developed severe abdominal pain, frequent vomiting, and signs of neurotoxic envenomation leading to respiratory paralysis. The patient did not respond to Indian polyvalent antivenom given 4 h after the bite and died under treatment 8 h after the bite. This is the second time that a B. niger was observed in Nepal, the first documented case of envenomation by this species in the country and the sixth reported case worldwide. Conclusions Previous distribution records from eastern India and western Nepal, from western hills in Nepal, and from lowland localities in India and Bangladesh indicate risk of envenomation by B. niger throughout the low and intermediate elevations of Nepal up to at least 1,500 m above sea level. As very few people in Nepal bring killed snakes to healthcare centers and because there is a general belief among local people that there are no kraits in the hills, bites by B. niger are likely to be misdiagnosed and underreported.

Quadros clínico-patológicos do envenenamento ofídico por Crotalus durissus terrificus e Bothrops spp: em animais de produção / Clinical and pathological pictures of snakebite poisoning by Crotalus durissus terrificus and Bothrops spp: in livestock

Foi realizada uma revisão dos quadros clínico-patológicos causados pelos venenos de Crotalus durissus terrificus e Bothrops spp. em bovinos, búfalos, ovinos equinos e suínos. Foram compilados os dados obtidos pela experimentação em animais de produção encontrados na literatura e os obtidos através de experimentação realizada por nossa equipe. Também foram revisados os casos naturais de envenenamento ofídico comunicados. Em dois Quadros foram lançados os mais importantes dados dessas revisões, que revelou diversos aspectos interessantes: 1) em nossos experimentos, o veneno de Crotalus durissus terrificus, quando injetado por via subcutânea em cavalos, causou um edema acentuado no local da aplicação, ao contrário do que tem sido observado em todas as outras espécies animais, aspecto não relatado na literatura; 2) em nossos experimentos, o veneno de diversas espécies de Bothrops, quando injetado por via subcutânea em bovinos, ovinos e equinos, não causou edema como em geral é relatado na literatura, e sim hemorragias subcutâneas acentuadas no local da aplicação. Nos casos não fatais este sangue era reabsorvido em poucos dias sem deixar sequelas. Exceção foi a reação ao veneno de Bothrops jararacussu, que causou edema nos ovinos experimentais, e tumefação acentuada que resultou em fístula com eliminação de líquido seroso nos equinos experimentais. O objetivo do presente estudo visa contribuir para o aperfeiçoamento do diagnóstico de acidentes ofídicos em animais de produção.

A review was performed about the clinical and pathological pictures caused by the venoms of Crotalus durissus terrificus and Bothrops spp. in cattle, buffaloes, horses, sheep and swine. The data were compiled from experiments in livestock species found in the literature, from experimentation accomplished by our research group, and from communicated natural cases of snakebite poisoning. The most important data were placed on two Tables, the analysis of which revealed some interesting aspects: (1) in our experiments the venom of Crotalus durissus terrificus caused in horses severe edema at the site of subcutaneous injection, to the contrary as observed in all other experimental animal species, an aspect not recorded in the literature; (2) in our experiments the venom of Bothrops species in cattle, sheep and horses, injected subcutaneously, did not cause edema as generally reported in the literature, but caused severe subcutaneous hemorrhages at the injection site. In the non fatal cases the blood was reabsorbed in a few days without leaving sequelae; exception was the reaction to the venom of Bothrops jararacussu, which caused edema in the experimental sheep, and severe tumefaction resulting in fistulous elimination of serous liquid in the experimental horses. The aim of this study was to contribute for the diagnostic of snakebite accidents in livestock.

Quadros clínico-patológicos do envenenamento ofídico por Crotalus durissus terrificus e Bothrops spp. em animais de produção / Clinical and pathological pictures of snakebite poisoning by Crotalus durissus terrificus and Bothrops spp. in livestock

Foi realizada uma revisão dos quadros clínico-patológicos causados pelos venenos de Crotalus durissus terrificus e Bothrops spp. em bovinos, búfalos, ovinos equinos e suínos. Foram compilados os dados obtidos pela experimentação em animais de produção encontrados na literatura e os obtidos através de experimentação realizada por nossa equipe. Também foram revisados os casos naturais de envenenamento ofídico comunicados. Em dois Quadros foram lançados os mais importantes dados dessas revisões, que revelou diversos aspectos interessantes: 1) em nossos experimentos, o veneno de Crotalus durissus terrificus, quando injetado por via subcutânea em cavalos, causou um edema acentuado no local da aplicação, ao contrário do que tem sido observado em todas as outras espécies animais, aspecto não relatado na literatura; 2) em nossos experimentos, o veneno de diversas espécies de Bothrops, quando injetado por via subcutânea em bovinos, ovinos e equinos, não causou edema como em geral é relatado na literatura, e sim hemorragias subcutâneas acentuadas no local da aplicação. Nos casos não fatais este sangue era reabsorvido em poucos dias sem deixar sequelas. Exceção foi a reação ao veneno de Bothrops jararacussu, que causou edema nos ovinos experimentais, e tumefação acentuada que resultou em fístula com eliminação de líquido seroso nos equinos experimentais. O objetivo do presente estudo visa contribuir para o aperfeiçoamento do diagnóstico de acidentes ofídicos em animais de produção.(AU)

A review was performed about the clinical and pathological pictures caused by the venoms of Crotalus durissus terrificus and Bothrops spp. in cattle, buffaloes, horses, sheep and swine. The data were compiled from experiments in livestock species found in the literature, from experimentation accomplished by our research group, and from communicated natural cases of snakebite poisoning. The most important data were placed on two Tables, the analysis of which revealed some interesting aspects: (1) in our experiments the venom of Crotalus durissus terrificus caused in horses severe edema at the site of subcutaneous injection, to the contrary as observed in all other experimental animal species, an aspect not recorded in the literature; (2) in our experiments the venom of Bothrops species in cattle, sheep and horses, injected subcutaneously, did not cause edema as generally reported in the literature, but caused severe subcutaneous hemorrhages at the injection site. In the non fatal cases the blood was reabsorbed in a few days without leaving sequelae; exception was the reaction to the venom of Bothrops jararacussu, which caused edema in the experimental sheep, and severe tumefaction resulting in fistulous elimination of serous liquid in the experimental horses. The aim of this study was to contribute for the diagnostic of snakebite accidents in livestock.(AU)

Biochemical and biological analysis of Philodryas baroni (Baron's green racer; Dipsadidae) venom: relevance to the findings of human risk assessment.

Philodryas baroni--an attractively colored snake--has become readily available through the exotic pet trade. Most people consider this species harmless; however, it has already caused human envenomation. As little is known about the venom from this South American opisthoglyphous "colubrid" snake, herein, we studied its protein composition by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), as well as its effects on the hemostatic system. Both reducing and nonreducing SDS-PAGE analysis demonstrated that the venom exhibits greatest complexity in the range of 50-80 kDa. The venom displayed proteolytic activity toward azocollagen, with a specific activity of 75.5 U mg⁻¹, and rapidly hydrolyzed the Aα-chain of fibrinogen, exhibiting lower activity toward the Bß- and γ-chains. The venom from P. baroni showed no platelet proaggregating activity per se, but it inhibited collagen- and thrombin-induced platelet aggregation. Prominent hemorrhage developed in mouse skin after intradermal injection of the crude venom, and its minimum hemorrhagic dose was 13.9 µg. When injected intramuscularly into the gastrocnemius of mice, the venom induced local effects such as hemorrhage, myonecrosis, edema, and leucocyte infiltration. Due to its venom toxicity shown herein, P. baroni should be considered dangerous to humans and any medically significant bite should be promptly reviewed by a qualified health professional.

Biochemical comparison of venoms from young Colombian Crotalus durissus cumanensis and their parents

Crotalus durissus cumanensis, a rattlesnake endemic to Colombia and Venezuela, is considered one of the most lethal snake species in Latin America. The aim of the present study was to compare the protein content and biological activity of the venom obtained from eight specimens of C. durissus cumanensis, namely two adults from different localities of Colombia and six offspring born in captivity. Protein profiles of crude venoms were analyzed by SDS-PAGE and RP-HPLC, and biological activities were evaluated for lethality, edema, defibrination, hemolytic and coagulant activities to assess individual venoms of adults and a pool of young snake venoms. Transient edema appeared rapidly after venom inoculation, whereas hemorrhagic effect was not observed. Differences in protein profiles, lethality, hemolytic, coagulant and defibrinating activities between both adult snake venoms were observed; those from the mother snake exhibited higher activities. Venoms from young snakes were similar to the one obtained from the mother, but the coagulant effect was stronger in offspring venoms. Notably, biological effects of the father snake venom were not comparable to those previously described for C. durissus cumanensis from Venezuela and C. durissus terrificus from Brazil, confirming the high variability of the venom from Crotalus species.(AU)

Novel insights into capillary vessel basement membrane damage by snake venom hemorrhagic metalloproteinases: a biochemical and immunohistochemical study.

The hemorrhagic activity characteristic of viperid snake envenomations is due to the action of venom metalloproteinases (SVMPs) on the capillary vessel basement membrane (BM). This study compared the action of two SVMPs on BM in vitro (degradation of Matrigel) and in vivo (immunohistochemical assessment of BM markers in mouse gastrocnemius muscle). SVMPs BaP1 (belonging to the P-I class) and jararhagin (of the P-III class) had a similar proteolytic activity on azocasein and degraded Matrigel with a slightly different cleavage pattern, since BaP1 exerted a limited proteolysis of both laminin and nidogen, whereas jararhagin predominantly degraded nidogen. In contrast with this pattern of limited proteolysis of BM proteins observed in vitro, immunohistochemical analysis of laminin, nidogen and type IV collagen, as well as of the endothelial cell marker VEGFR-2, in the hemorrhagic areas in the muscle, revealed a pronounced reduction in the immunostaining of these three BM components, associated with a loss of the endothelial cell marker. BM of muscle fibers was affected to a lesser extent. In conclusion, in vitro results demonstrated that SVMPs induce a pattern of limited proteolysis on BM components. The drastic loss of these antigens in affected capillaries in vivo is likely to depend on the combination of limited proteolysis of BM and the action of hemodynamic biophysical forces, previously shown to play a role in SVMP-induced capillary damage, which may cause a mechanical disruption of BM structure.

Systemic pathological alterations caused by Philodryas patagoniensis colubrid snake venom in rats.

Very little is known about the systemic effects caused by Philodryas patagoniensis colubrid snake venom. In this work, this venom was tested for its ability to induce histopathological changes in rats after its intramuscular, subcutaneous or intravenous administration, by light microscopic examination of some organs (cerebellum, cerebrum, lung, liver, kidney and heart). Four rats were used for each dose of 0.23, 0.45 and 0.90 mg of venom in 0.3 ml of phosphate-buffered saline solution (pH 7.4). Aliquots of blood were withdrawn at different time intervals for enzymatic determination of alanine aminotransferase, aspartate aminotransferase and creatine kinase levels. After 2h the animals were killed by an overdose of anesthetic, and samples of kidney, heart, liver, lung, cerebrum and cerebellum were taken to microscopic examination (hematoxylin and eosin stain). Histologically, no abnormality was observed in heart tissue, in none of the administration routes of the venom used. However, histological observations showed multifocal hemorrhage in cerebellum, cerebrum and lung sections, severe peritubular capillary congestion in kidney sections and hydropic degeneration in liver sections, when venom was administrated intravenously. The subcutaneous route showed similar results to the previous one, with the exception of cerebellar hemorrhage. Intramuscularly, neither cerebral nor cerebellar hemorrhage was observed. Plasma alanine aminotransferase and aspartate aminotransferase increased levels were demonstrated, mainly when venom was administered intravenously or subcutaneously. Our results suggest that P. patagoniensis venom induces moderate histopathological changes in vital organs of rats. These changes are initiated at early stages of the envenomation and may be associated with a behavioral or functional abnormality of those organs during envenoming.

Assessment of efficacy of bothropic antivenom therapy on microcirculatory effects induced by Bothrops jararaca snake venom.

Intravenous administration of antibothropic antivenom (BAv) neutralises the systemic effects, but does not efficiently reverse the local symptoms elicited by the Bothrops jararaca venom (BjV). The mechanisms involved in this poor protection have not been clarified. In this work, intravital microscopy studies were carried out to determine the efficacy of different schedules of BAv treatment on local effects evoked by topical application of BjV in the microcirculatory network of the internal spermatic fascia of Wistar rats. Results demonstrated that BAv administration 15 min before, simultaneously with, or 15 min after BjV application did not totally reverse the local symptoms, represented by disturbances of coagulation, development of haemorrhage lesions, vascular permeability increase and increment on leukocyte-endothelium interactions. This lack of effectiveness neither reflects an inadequate amount of specific antibodies in the antivenom against toxins responsible for local effects nor an insufficient dose of circulating BAv during the assays. Administration of fluorescein isothiocyanate (FITC) labelled-BAv showed the dynamics of distribution of the antivenom in the microcirculatory network. Images obtained from prior and simultaneously treated animals showed that the antivenom remains at luminal side of vessels before venom application, and the latency time to antivenom leakage is coincidental to that for local effects evoked by the venom. In addition, images from posterior treatment demonstrated that the intense alterations in the microcirculatory network impair antivenom distribution at the site of injection. Together, our data show that the lack of effectiveness of antivenom therapy is due to impaired and delayed venom and antivenom interaction at the site of injury.

Hemorragía del sistema nervioso central y emponsoñamiento ofidico bothropico: modificado por anticuagulantes orales a propósito de un caso / Hemohrrage of the central nervous system and poisoning type bothrops: modification for anticoagulants oral a purpose of a case

El empozoñamiento en Venezuela es bastante frecuente. Tenemos tres tipos de serpientes: Bothrops, Crotabus y Lachesi. El caso que presentamos es del tipo Bothrops en una mujer de 66 años de edad con historia de ingestión de anticoagulantes orales y presenta complicaciones secundarios al empozoñamiento ofídico asociado a la anticoagulación vía oral