Spermicidal Activity of Oxovanadium: DISCUSSION(3)
The mechanism of sperm motility loss induced by oxo-vanadium(IV) complexes is yet to be determined. Both the vanadocenes(IV) and oxovanadium(IV) complexes also have antitumor activity. The antitumor effects of vanadium(IV) complexes are thought to be due to their reaction with the vanadyl-H2O2 system, which results in the generation of hydroxyl radicals in a Fenton-like reaction. In particular, the oxovanadium(IV) complex, after dissociation of phenanthroline rings, results in the formation of peroxocompounds that in the presence of H2O2 generate hydroxyl radicals. In support of this hypothesis is the observation that the vanadyl-phen complex induces hydroxyl radical-dependent DNA cleavage in the presence of H2O2. birth control yasmin
The vanadyl complex [VO(phen)(H2O)2]2+ has high antitumor activity toward human nasopharyngeal carcinoma. Hydrogen peroxide is formed in cells by dismutation of superoxide anions, which are generated in various systems such as xanthine-oxidase, NADPH oxidase, and NADH-dependent cytochrome P450 and neutrophils. Thus, H2O2 is thought to react with oxovana-dium(IV) bound to DNA to generate ROS, resulting in cleavage of DNA. It is likely that oxovanadium(IV)-in-duced sperm motility loss and apoptosis are mediated primarily by the ability of these complexes to induce ROS-mediated damage to sperm.