Glutathione and caffeine antagonize the sperm-immobilizing effect of a vaginal contraceptive

The concentration-dependent inhibition of Neosampoon, a vaginal contraceptive, on ejaculated human sperm motility was studied with a transmembrane migration method. Caffeine (5mM), glutathione (5mM) and glutathione (15mM) all reactivated the motility of Neosampoon-immobilized sperm. Caffeine (5mM) was more potent than glutathione in antagonizing Neosampoon; there was no difference between the potency of 5mM- and 15mM-glutathione. Human sperm motility could be a model for studying the interaction of membrane-active drugs, including the protective effect of glutathione against membrane-disrupting agents.