CONICET | Buscador de Institutos y Recursos Humanos

We tested the cytotoxic effect of the crude venoms of Crotalus durissus terrificus (Cdt) and B. ammodytoides (Bamm) as well as the effect of the acidic phospholipase from Bamm. venom on leukemic cell lines K562 and Kv562. Crude venoms were obtained from specimens of Cdt and Bamm by manual extraction, vacuum dried, and stored at -20ºC until used. The enzyme was purified through three chromatographic steps: Sephadex G75, Mono-S in a FPLC system and a C18 column in a HPLC system. The leukaemia cell lines used were K562 and Kv562 (vincristine resistant) lines. Cells were incubated with different amounts of the venoms (2.5, 5, 10 and 20 μg/ml) for 24h and then the cytotoxic effect was evaluated by flow cytometry (FDA/IP). The isolated enzyme did not show cytotoxic activity. However, Bamm and Cdt venoms produced cytotoxicity in a dose dependent manner. Both venoms produced over 80% of cellular death in K562 or Kv562 cell lines at 20 μg/ml. The EC50 values were for K562 cells: 7.98 μg/ml (95% c.i. 1 to 58) and 5.95 μg/ml (4.1 to 8.67) for Bamm and Cdt respectively. Values for Kv562 were 8.27 μg/ml (5.98 to 11.44) and 6.62 μg/ml (3.87 to 11.34) for Bamm and Cdt respectively. Cytotoxic effect due to Bothrops venoms or its components has been described for different cellular types. This activity can be caused by several components of the venoms (PLA2, SVMP, LAO, disintegrins and lectins). In this case the acidic PLA2 of Bamm venom, did not show any toxicity, although the crude venom showed cytotoxic effect similar to that obtained using Cdt venom. The reason why snake venoms cytotoxic components are active on malignant cells while exert low toxicity in normal tissues, is not clear yet. This characteristic of the venoms and its components might have important practical pharmaceutical utility. The component/s responsible for this activity in this venom is under study.