Mylabris, the dried body of Chinese blister beetle, is a notorious insect because it contains a natural toxin, cantharidin, a defensive chemical that is reported to possess aphrodisiac and abortifacient properties in human. In this study we attempt to verify the action of cantharidin on the testosterone production from rat dispersed Leydig cells in vitro. Leydig cells obtained from testes of Wistar rats were treated with oLH, cAMP, and cantharidin by using in vitro culture system. The results showed that cantharidin with 10 ng/ml is able to inhibit the testosterone production from rat Leydig cells at basal secretion and in response to the oLH and cAMP stimulations. It is implied that ingestion of cantharidin decreases testosterone secretion from testes and such action involves a post-cAMP mechanism.
