The phytoestrogen, diosgenin, directly stimulates ovarian cell functions in two farm animal species.

The present in vitro study was conducted to examine the direct action of the plant steroidal sapogenin, diosgenin, on basic farm animal ovarian cell functions. As models, we used cultured porcine ovarian granulosa cells, porcine whole follicles, and rabbit ovarian fragments. The effects of diosgenin (0, 1, 10, or 100 μg/mL medium) on the markers of proliferation, cytoplasmic apoptosis, steroid (progesterone: P4, testosterone: T, and estradiol: E2) release, and peptide hormone (insulin-like growth factor I: IGF-I) release were analyzed by quantitative immunocytochemistry and radioimmunoassay. Diosgenin promoted proliferation, apoptosis, and T and E2 release and inhibited P4 output in cultured porcine granulosa cells. Similarly, cultured porcine ovarian follicles showed diosgenin-induced inhibition of P4 and stimulation of T release. In cultured rabbit ovarian fragments, diosgenin stimulated P4 and IGF-I release. This is the first study showing that diosgenin can promote basic ovarian cell functions such as proliferation, apoptosis, and steroid and peptide hormone release. The similar effects of diosgenin on porcine granulosa cells and ovarian follicles suggest that granulosa cells are the primary ovarian target of diosgenin. The contrasting effects of diosgenin on porcine and rabbit ovarian P4 output suggest that diosgenin functions in a species-specific manner. These observations indicate that diosgenin has potential applications for improving female reproduction.