Exploiting exopolysaccharides from microalgae to block the toxic in vitro effects of Bothrops sp. venom.

Snakebite envenomation causes various toxic effects in humans, including death. Antivenoms are effectively prevent death but cannot completely block local muscle tissue damage, resulting in amputation and disability; thus, complementary therapies are needed. In this study, the ability of exopolysaccharides extracted from the microalgae Chlorella sorokiniana, Scenedesmus obliquus, Nannochloris sp. Naumann, and Scenedesmus acuminatus to inhibit the proteolytic, plasma coagulant, and phospholipase A2 (PLA2) activities of Bothrops jararaca, B. jararacussu, and B. neuwiedi venoms was assessed. Exopolysaccharides from C. sorokiniana, S. obliquus, Nannochloris sp. Naumann, and S. acuminatus inhibited the proteolytic activity of B. jararaca venom by 25%, 99%, 97%, and 13%, respectively; B. jararacussu venom by 14%, 50%, 46%, and 12%, respectively; and B. neuwiedi venom by 1%, 78%, 62%, and 1%, respectively. Exopolysaccharides from S. obliquus and Nannochloris sp. Naumann prevented the coagulation induced by snake venom and decreased the PLA2 activity by 15% and 30%, respectively. None of the four exopolysaccharides lysed red blood cells and, thus, can be considered as nonhemotoxic compounds. Therefore, microalgae exopolysaccharides may be a candidate as complementary therapies for envenomation by snakes in regions where such incidents are common.