Effect of photobiomodulation on endothelial cell exposed to Bothrops jararaca venom.

Bleeding is a common feature in envenoming caused by Bothrops snake venom due to extensive damage to capillaries and venules, producing alterations in capillary endothelial cell morphology. It has been demonstrated, in vivo, that photobiomodulation (PBM) decreases hemorrhage after venom inoculation; however, the mechanism is unknown. Thus, the objective was to investigate the effects of PBM on a murine endothelial cell line (tEnd) exposed to Bothrops jararaca venom (BjV). Cells were exposed to BjV and irradiated once with either 660- or 780-nm wavelength laser light at energy densities of 4 and 5 J/cm(2), respectively, and irradiation time of 10 s. Cell integrity was analyzed by crystal violet and cell viability/mitochondrial metabolism by MTT assay. The release of lactic dehydrogenase (LDH) was quantified as a measure of cell damage. In addition, cytokine IL1-ß levels were measured in the supernatant. PBM at 660 and 780 nm wavelength was able to increase cellular viability and decrease the release of LDH and the loss of cellular integrity. In addition, the concentration of pro-inflammatory cytokine IL1-ß was reduced after PBM by both wavelengths. The data reported herein indicates that irradiation with red or near-infrared laser resulted in protection on endothelial cells after exposure to Bothrops venom and could be, at least in part, a reasonable explanation by the beneficial effects of PBM inhibiting the local effects induced by Bothrops venoms, in vivo.

Efeito da terapia LED (Light Emitting Diode) na mionecrose e edema induzidos pelo veneno a serpente Bothrops jararaca, no músculo gastrocnêmio / Effect of LED (Light Emission Diode) therapy on edema formation and myonecrosis induced by Bothrops jararaca snake venom, on gatrocnemius muscle

Introdução: O envenenamento causado pela serpente Bothrops jararaca induz, de modo geral, um quadro fisiopatológico caracterizado por reações locais imediatas, com hemorragia, mionecrose, edema e dor, que não é revertido pelo tratamento com o antiveneno. Objetivo: Neste trabalho avaliou-se a capacidade da terapia LED (Light EmitionDiode) para diminuir o edema e a mionecrose causada pelo veneno de B. jararaca. Método: Foram utilizados camundongos wiss machos injetados com veneno de B. jararaca (2 mg/kg) no músculo gastrocnêmio. O edema foi avaliado nos tempos 3 e 24 h após a injeção do veneno ou salina. O aumento do edema foi expresso como a diferença do volume do peso úmido e peso seco, dos músculos tratados com o veneno, comparado com o volume do músculo contralateral (controle). A mionecrose foi avaliada através da quantificação da enzima creatino quinase no tempo de 3 h e da análise histológica dos músculos 3 e 24 h após a injeção do veneno. Os animais foram tratados com os LEDs (LED infravermelho, potência de 120 mW, À 945 nm, densidade de energia de 4 J/cm2, tempo de irradiação de 38 s e área of 1,2 cm2; LED vermelho potência de 110 mW, À 635 nm, densidade de energia de 4 J/cm2, tempo de irradiação de 41 s e área de 1,2 cm2) nos tempos: imediatamente e 2 horas após a injeção do veneno. Resultados: O edema muscular causado pelo veneno de B. jararaca foi significativamente reduzido pelos dois tratamentos utilizados: LED vermelho 20 e 11% e LED infravermelho: 29 e 19%, às 3 e 24 h respectivamente, quando comparado com os animais tratados com o veneno. O tratamento com o LED não modificou a mionecrose causada pelo veneno. Conclusões: A terapia LED foi eficaz em reduzir o edema muscular, no entanto, a mionecrose não foi afetada pelo tratamento com os LEDs. Desta maneira, a terapia com o LED pode contribuir, ao menos em parte, como uma alternativa ao tratamento atual, adicionado a terapia disponível com antivenenos, não efetiva contra os efeitos locais.

Introduction: Envenoming caused by Bothrops jararaca venom induces, in general, a physiopatologic reaction characterized by immediate local reactions, with hemorrhage, mionecrosis, edema and pain, which are not reverted by thetreatment with antivenenom. Objetive: In this work, it was evaluated the capacity of LED (Light Emition Diode) therapy to diminish the edema formation and mionecrosis, caused by Bothrops jararaca venom. Methods: Swiss mice had been injected with B. jararaca venom (2 mg/kg) in the gastrocnemius muscle. Edema was evaluated at 3 and 24 after the injection of the venom or saline. The increase on edema formation was expressed as the difference betweethe humid and dry weight, of the muscles injected with the poison, compared with the volume of the contralateral muscle (control). Mionecrosis was evaluated through the quantification of the creatine kinase enzyme at 3 h and by histologic analysis of the muscle, 3 and 24 h after the injection of the venom. The animais had been treated with the LE(infra-red: power of 120 mW, li 945 nm, density of energy of 4 J/cm2, time of irradiation of 38 s and area of 1,2 cm2; Red LED: power of 110 mW, li 635 nm, density of energy of 4 J/cm 2, time of irradiation of 41 s and area of 1,2 cm 2) applied: immediately and 2 h after the venom injection. Results: Muscular edema caused by the B. jararaca venom was significantly reduced by the two treatments: Red LED: 20 and 11% and infrared LED: 29 and 19%, to 3 and 24 t;respectively, when compared with the animais treated with venom. The treatment with the LED did not modify the mionecrosis caused by the venom. Conclusion: LED therapy was efficient in reducing muscular edema, however, mionecrosis was not affected by these treatment. In this way, the LED therapy can contribute, at least in part, as an alternative added to the available therapy with antivenoms, which are not effective against the local effect.

Inflammatory effects of snake venom metalloproteinases.

Metalloproteinases are abundant enzymes in crotaline and viperine snake venoms. They are relevant in the pathophysiology of envenomation, being responsible for local and systemic hemorrhage frequently observed in the victims. Snake venom metalloproteinases (SVMP) are zinc-dependent enzymes of varying molecular weights having multidomain organization. Some SVMP comprise only the proteinase domain, whereas others also contain a disintegrin-like domain, cysteine-rich, and lectin domains. They have strong structural similarities with both mammalian matrix metalloproteinases (MMP) and members of ADAMs (a disintegrin and metalloproteinase) group. Besides hemorrhage, snake venom metalloproteinase induce local myonecrosis, skin damage, and inflammatory reaction in experimental models. Local inflammation is an important characteristic of snakebite envenomations inflicted by viperine and crotaline snake species. Thus, in the recent years there is a growing effort to understand the mechanisms responsible for SVMP-induced inflammatory reaction and the structural determinants of this effect. This short review focuses the inflammatory effects evoked by SVMP.

Inflammatory effects of snake venom metalloproteinases

Metalloproteinases are abundant enzymes in crotaline and viperine snake venoms. They are relevant in the pathophysiology of envenomation, being responsible for local and systemic hemorrhage frequently observed in the victims. Snake venom metalloproteinases (SVMP) are zinc-dependent enzymes of varying molecular weights having multidomain organization. Some SVMP comprise only the proteinase domain, whereas others also contain a disintegrin-like domain, cysteine-rich, and lectin domains. They have strong structural similarities with both mammalian matrix metalloproteinases (MMP) and members of ADAMs (a disintegrin and metalloproteinase) group. Besides hemorrhage, snake venom metalloproteinase induce local myonecrosis, skin damage, and inflammatory reaction in experimental models. Local inflammation is an important characteristic of snakebite envenomations inflicted by viperine and crotaline snake species. Thus, in the recent years there is a growing effort to understand the mechanisms responsible for SVMP-induced inflammatory reaction and the structural determinants of this effect. This short review focuses the inflammatory effects evoked by SVMP.