The effects of low-level laser on muscle damage caused by Bothrops neuwiedi venom

Journal of Venomous Animals and Toxins including Tropical Diseases, Feb 2019

The present study aimed to assess the effects of low-level laser (660 nm) on myonecrosis caused by the insertion of Bothrops neuwiedi venom in the gastrocnemius muscle of rats. Male Wistar rats were divided into three groups (n = 24 each): Group S (0.9% saline solution); Group V (venom) and Group VLLL (venom plus low-level laser). These categories were subdivided into four additional groups (n = 6) based on the euthanasia timing (3 hours, 24 hours, 3 days and 7 days). The groups V and VLLL were inoculated with 100 µL of concentrated venom (40 µg/mL) in the gastrocnemius muscle. The muscle was irradiated using a gallium-aluminum-arsenide laser (GaAlAs) at 35 mW power and 4 J/cm² energy density for 3 hours, 24 hours, 3 days or 7 days after venom inoculation. To evaluate the myotoxic activity of the venom, CK activity was measured and the muscle was histologically analyzed. The low-level laser reduced venom-induced CK activity in the groups euthanized at 3 hours, 24 hours and 3 days (p < 0.0001). Histological analysis revealed that low-level laser reduced neutrophilic inflammation as well as myofibrillar edema, hemorrhage and myonecrosis following B. neuwiedi envenomation. These results suggest that low-level laser can be useful as an adjunct therapy following B. neuwiedi envenomation.

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The effects of low-level laser on muscle damage caused by Bothrops neuwiedi venom

ORIGINAL PAPER   The effects of low-level laser on muscle damage caused by Bothrops neuwiedi venom     Dourado DMI; Matias RI; Almeida MFI. De Paula KRI; Vieira RPIII; Oliveira LVFII; Carvalho PTCI ILaboratory of Experimental Histopathology, University for the Development of the State and of the Region of Pantanal, UNIDERP, Campo Grande, Mato Grosso do Sul State, Brazil IIMasters Program in Rehabilitation Sciences, Nove de Julho University, UNINOVE, São Paulo, São Paulo State, Brazil IIIDepartment of Pathology and Physical Therapy, School of Medicine, University of São Paulo, São Paulo, São Paulo State, Brazil Correspondence to     ABSTRACT The present study aimed to assess the effects of low-level laser (660 nm) on myonecrosis caused by the insertion of Bothrops neuwiedi venom in the gastrocnemius muscle of rats. Male Wistar rats were divided into three groups (n = 24 each): Group S (0.9% saline solution); Group V (venom) and Group VLLL (venom plus low-level laser). These categories were subdivided into four additional groups (n = 6) based on the euthanasia timing (3 hours, 24 hours, 3 days and 7 days). The groups V and VLLL were inoculated with 100 µL of concentrated venom (40 µg/mL) in the gastrocnemius muscle. The muscle was irradiated using a gallium-aluminum-arsenide laser (GaAlAs) at 35 mW power and 4 J/cm² energy density for 3 hours, 24 hours, 3 days or 7 days after venom inoculation. To evaluate the myotoxic activity of the venom, CK activity was measured and the muscle was histologically analyzed. The low-level laser reduced venom-induced CK activity in the groups euthanized at 3 hours, 24 hours and 3 days (p < 0.0001). Histological analysis revealed that low-level laser reduced neutrophilic inflammation as well as myofibrillar edema, hemorrhage and myonecrosis following B. neuwiedi envenomation. These results suggest that low-level laser can be useful as an adjunct therapy following B. neuwiedi envenomation. Key Words: myonecrosis, B. neuwiedi venom, low-level laser.     INTRODUCTION The Bothrops neuwiedi (Neuwied's lancehead) species complex consists of a variety of subspecies widely distributed throughout South America (1). In general, the prevalence of Bothrops ophidian accidents in Brazil is approximately 85% when compared with other species (24). Bothrops neuwiedi venom causes fibrinolytic, hemorrhagic and anticoagulant effects (9, 12). The main local actions are tissue necrosis and endothelial injury, while systemic effects include release of inflammatory and vasoactive mediators (1, 17, 22). Envenomation by Bothrops snakes results in serious wounds, muscular necrosis, pain, edema, ecchymosis, abscess and hemodynamic changes (24). The affected area exhibits ischemia as a consequence of serious vascular lesions and profuse bleeding. Hemorrhage is caused by the action of metalloproteases, which damages the collagen and other capillary vessel components of the basal lamina. As a result, the capillary vessels are broken, causing ecchymosis. These dysfunctions and local wounds are specific clinical symptoms of B. neuwiedi envenomation (17). Several myotoxins have been isolated from Bothrops snake venoms and their effects appear to be similar to other toxins found in crotalic venoms, such as Crotalus durissus terrificus (23). Intramuscular injection of Bothrops myotoxins leads to a rapid series of drastic degenerative events, probably initiated at the plasma membrane level, that culminate in selective skeletal muscle necrosis. Muscle damage, cytolysis and liposome disruption occur under conditions in which phospholipase A2 activity is inhibited, while enzymatic activity may enhance the myotoxin action (9). A large number of researchers have been looking for new therapeutic methods to repair or at least minimize the damage caused by Bothrops snake venom to the muscles (3, 5, 10). Low-level laser therapy can be considered an alternative if we consider its sequelae on different types of biological tissues – including its trophic-regenerative, anti-inflammatory and analgesic effects – which have been demonstrated in both in vitro and in vivo studies (2, 4, 6-8, 11, 18, 19, 21, 24-26). The present study aimed to assess the effects of low-level laser (660 nm) on myonecrosis caused by the injection of B. neuwiedi venom into the gastrocnemius muscle of Wistar rats.   MATERIALS AND METHODS Venom Natural venom was extracted from B. neuwiedi snakes that were captured in the Pantanal region on Mato Grosso do Sul State, Brazil, and kept at the Zoology Laboratory of the University for the Development of the State and of the Region of Pantanal, UNIDERP, Campo Grande. This extracted venom was lyophilized and stored at –20º C. Animals Seventy-two adult male Wistar rats (Rattus norvegicus albinus), weighing 200 to 300 g, obtained from the central animal house at UNIDERP, were kept in 12 cages (six animals per cage) under controlled lighting and temperat (...truncated)


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DM Dourado, R Matias, MF Almeida, KR De Paula, RP Vieira, LVF Oliveira, PTC Carvalho. The effects of low-level laser on muscle damage caused by Bothrops neuwiedi venom, Journal of Venomous Animals and Toxins including Tropical Diseases, pp. 423-434, Volume 14, Issue 3, DOI: 10.1590/S1678-91992008000300004