Lycium barbarum Glycopeptide Promotes Testosterone Synthesis and Glucose Metabolism in Leydig Cells of the Testis

<i>Lycium barbarum</i> extracts have been shown to be effective in male reproductive protection and male infertility. However, its role in enhancing testicular function, such as testosterone synthesis, and the potential mechanism remain to be understood. To elucidate the effects of <i>Lycium barbarum</i> glycopeptide (LbGp) on testosterone synthesis, we isolated primary Leydig cells (LCs) from testes and performed RNA sequencing (RNA seq) on LCs treated with LbGp. In this study, we demonstrated that LbGp promoted testosterone synthesis in LCs both in vivo and in vitro. We also demonstrated that LbGp elevated adenosine 5'-triphosphate (ATP) synthesis and cell proliferation by enhancing glucose metabolism. Mechanistically, LbGp upregulated testosterone synthesis by suppressing TGF-β pathway and enhancing the expression of steroidogenic genes: <i>Cyp11a1</i>, <i>Hsd3b1</i>, <i>Hsd17b3</i>, <i>Star</i>, and <i>Sf-1</i>. These findings indicate that LbGp plays an important role in enhancing testicular function and promoting testosterone synthesis.