Gossypol is a male antifertility agent with antispermatogenic activity and has been shown to contain anitumor, anitviral, and antioxidant properties. Gossypol is a reversible inhibitor of PP2B (protein phosphatase 2B), mitotic kinesin Eg5, and PKC (protein kinase C). Gossypol also potentially inhibits PAF-R, Bcl-2, 5-LO (5-lipoxygenase), 12-LO, and leukotriene-induced guinea pig parenchyma contractions. Gossypol is an inhibitor of Bcl-xl, PKD and p107.