Tumor cytotoxicity of leucurolysin-B, a P-III snake venom metalloproteinase from Bothrops leucurus

although it has been demonstrated that venoms and toxins from some snakes are able to influence the growth of tumor cells, few antitumoral compounds from bothrops leucurus venom have been characterized. leucurolysin-b (leuc-b) is a metalloproteinase class p-iii isolated from b. leucurus which possesses an ecd-disintegrin domain. both ecd-disentegrin and rgd-disintegrin are able to bind to cell surface integrins and inhibit their adherence to their natural ligands. in the present study, the potential efficacy and the cytotoxic effects of leuc-b on glioblastoma, breast cancer and melanoma cell lines were analyzed. the effect of leuc-b on cancer cell survival was evaluated and its 50% inhibitory concentration (ic50) was determined. morphological alterations were monitored by contrast phase and fluorescent microscopy. the results demonstrated that leuc-b has potent cytotoxic effect in a micromolar range against all evaluated cancer cell lines. morphologically, dying cells showed fragmentation, condensation of their contents concomitant with shrinkage and appearance of vacuoles. this study reports for the first time the cytotoxic effect of leuc-b from b. leucurus snake venom on tumor cells.