Protective Effect of Ursolic Acid in Prunella vulgaris L. on LPS-Induced Asthenozoospermia via Bcl-2/Bax Apoptosis Signaling Pathway

Background: Asthenozoospermia, also known as lack of sperm motility, accounts for about 27.8% of male infertility as a separate factor, and is often associated with abnormal quantity and morphology of spermatozoa. Therefore, oligozoospermia has become one of the most important factors affecting male infertility. Methods: Ursolic Acid (UA), also known as wusu acid, is the main active component isolated from Prunella vulgaris L. and has a variety of pharmacological effects. However, the protective effect of UA on asthenozoospermia disease has not been reported. In the current study, the purpose of this study was to investigate the regulatory effect of UA in rats with LPS-induced asthenozoospermia disease. SD rats were treated with 5 mg/kg LPS, respectively. Results: After different concentrations of UA were infused into the stomach of SD rats, microscopy, flow cytometry, Enzyme-Linked Immunosorbent Assay (ELISA), qRT-PCR and western blot were used to detect sperm motility, apoptosis, the levels of TNF-α, IL-1β and IL-6, and Bcl-2/Bax apoptosis pathway related proteins in rat serum and epididymis tissues. Discussion: Compared with the normal group, the sperm motility and Bcl-2 level in LPS group decreased significantly, while the expression of inflammatory factors and Bax proteins increased significantly (P<0.05). Compared with LPS group, UA intervention group has the opposite result and dose dependence. Conclusion: This study shows that UA can protect LPS-induced asthenozoospermia of rats by increasing sperm density and motility, regulating Bcl-2/Bax apoptosis pathway and reducing inflammatory apoptosis response. This experiment provides ideas for improving the clinical treatment of infertile patients with oligoasthenospermia.