Steroidogenic Effects of Korean Rice Bran Extract (Oryza sativa L.) on Mouse Normal Leydig Cells via Modulation of Steroidogenesis-Related Enzymes

Abstract

Background and objective Many plant extracts have various effects on diseases. In particular, some medicinal plants have been shown to have steroidogenic effects in men. However, the effects of Korean rice bran extract (RBE) on steroidogenesis in men have not been reported previously. Accordingly, in this study, we investigated the effects of RBE (Oryza sativa L.) on mouse normal Leydig cells (TM3), which produce testosterone with increasing levels of key enzymes (e.g., StAR, CYP11A1, and CYP17A1) for male steroidogenesis. Material and methods Using mouse normal Leydig cells (TM3), we determined whether RBE had steroidogenic effects by eval-uating changes in the levels of steroidogenesis-related enzymes, such as StAR (steroidogenic acute regu-latory protein), CYP11A1, and CYP17A1, using quantitative real-time PCR, western blotting analysis, and ELISA method. Results RBE significantly enhanced mRNA and protein levels of StAR, CYP11A1, and CYP17A1, thereby enhanc-ing synthetic testosterone levels in mouse Leydig TM3 cell supernatants. These findings indicated that RBE increased the levels of steroidogenic enzymes to modulate steroidogenesis. Conclusion RBE enhanced mRNA and protein levels of key enzymes including StAR, CYP11A1, and CYP17A1 for male steroidogenesis. These changes could induce testosterone production by TM3 cells in vitro. Thus, RBE may be used as a food additive or medicinal plant for the treatment of diseases characterized by insuf-ficient testosterone (e.g., late-onset hypogonadism).