Abstract
Water extracts from pawpaw seed have been reported to reversibly decrease the testicular weight and to suppress spermatogenesis, and fertility of Wistar rats. The reversible changes become evident, 30 - 45 days after the withdrawal of the extract. The possible effect of this extract on the activities of steroidogenic enzymes of the testis has not been investigated. Water extract of papaya seeds was administered to male Sprague Dawley rats ad libitum for 84 days. Following the discontinuation of the extracts, ten rats each were sacrificed on days 0, 10, 20 and 30 after the withdrawal. Their testes were quickly dissected out and frozen. Cryostat sections, 10µm thick were cut. These sections were used for immunohistochemical stains for side chain cleavage enzyme and aromatase, and for histochemical stains for 17-β Hydroxysteroid dehydrogenase, 3-β Hydroxysteroid dehydrogenase. We conclude that the water extract of papaya seed suppresses the activities of steroidogenic enzymes in the testis of Sprague Dawley rats, and that this may contribute to reversible suppression of spermatogenesis, a property that gives a possible male contraceptive potential.