Acteoside reduces testosterone by inhibiting cAMP, p450scc, and StAR in rat Leydig cells

The present study investigated the in vivo and in vitro effects of acteoside on testosterone production in Sprague-Dawley (SD) rats. The in vivo experiment revealed that acteoside reduced the testosterone level in serum significantly (P<0.05). The in vitro experiment also illustrated that acteoside significantly reduced testosterone production in SD rat Leydig cells in primary culture (P<0.05). Enzyme-linked immunosorbent assay results demonstrated that acteoside significantly reduced the cyclic adenosine 3',5'-monophosphate (cAMP) level (P<0.05), and Western blot analysis showed that acteoside significantly reduced cholesterol side-chain cleavage enzyme (p450scc) and steroidogenic acute regulatory (StAR) expression (P<0.05). Hoechst 33342 staining and Western blotting showed that acteoside did not induce apoptosis in Leydig cells. Together, these results suggest that the acteoside-induced reduction in testosterone production in rat may be at least partially due to down-regulation of cAMP, p450scc, and StAR, but not apoptosis.