Abstract: The invention relates to the use of phospholipases, v.gr. sPLA2, as an active agent in the production of pharmaceutical and/or cosmetic compositions for the treatment of diseases caused by micro-organisms, the envelope or membrane of which comprises phospholipids, particularly glycerophospholipids. In particular, said invention relates to the use of sPLA2 from Crotalus durissus terrificus venom as a biocide component for the preparation of compositions for the treatment of viral infections, particularly acquired immunodeficiency states VIH-1 and VIH-2, bacterial and parasitic infections, such as infections caused by plasmodium and leishmania-type parasites.

Abstract: The present invention provides a stable composition of matter based on the cytotoxic activity of a basic phospholipase A.sub.2 of molecular weight 14,500 and isoelectric point 9.6-9.7 (crotoxin B) isolated from the venom of Crotalus durissus terrificus which in complex with a specific, non-enzymatic, peptide of molecular weight 9,500 and isoelectric point 3.5-3.7 (crotoxin A) displays a preferential cytotoxic activity against various types of tumor cells. When administered parenterally in an acceptable vehicle and in pharmacologically efficient amounts to animals and humans the complex is useful in the treatment of malignant tumors in advanced stages. The method for purification of the active components, the preparation in a pharmacologically acceptable form, and the method of therapeutic use of the present composition of matter are also disclosed.