Ginsenosides stimulated the proliferation of mouse spermatogonia involving activation of protein kinase C.

The effect of ginsenosides on proliferation of type A spermatogonia was investigated in 7-day-old mice. Spermatogonia were characterized by c-kit expression and cell proliferation was assessed by immunocytochemical demonstration of proliferating cell nuclear antigen (PCNA). After 72-h culture, Sertoli cells formed a confluent monolayer to which numerous spermatogonial colonies attached. Spermatogonia were positive for c-kit staining and showed high proliferating activity by PCNA expression. Ginsenosides (1.0 approximately10 microg/ml) significantly stimulated proliferation of spermatogonia. Activation of protein kinase C (PKC) elicited proliferation of spermatogonia at 10(-8) to 10(-7) mol/L and the PKC inhibitor H(7) inhibited this effect. Likewise, ginsenosides-stimulated spermatogonial proliferation was suppressed by combined treatment of H(7). These results indicate that the proliferating effect of ginsenosides on mouse type A spermatogonia might be mediated by a mechanism involving the PKC signal transduction pathway.