Protective effects of Cynanchum auriculatum Royle ex Wight on testicular reproductive decline in naturally aging male rats

Background: The aging process leads to organ degeneration, including testicular aging, which not only impairs fertility but also increases the risk of reproductive system diseases, significantly reducing the quality of life in elderly individuals. Cynanchum auriculatum (C. auriculatum) Royle ex Wight exhibits anti-aging, antioxidant and anti-inflammatory properties; however, its effects on testicular reproductive function decline in naturally aging male rats remain underexplored. Objectives: This research explored the beneficial effects and underlying mechanisms of C. auriculatum on testicular reproductive function in aging male rats. Methods: We divided male SD rats into four groups: a middle-aged control group, an aging model group and groups receiving low and high doses of C. auriculatum. We collected testicular tissues to assess morphological alterations, DNA integrity and apoptotic activity. Results: Relative to the middle-aged control group, the aging model group exhibited marked reductions in both testicular weight and testicular index. Conversely, the C. auriculatum-treated groups demonstrated improvements in these indices along with enhanced seminiferous tubule structure. Furthermore, C. auriculatum administration led to a decrease in DNA damage and apoptosis, significantly suppressing phosphorylated histone H2AX (?-H2AX), BCL2-associated X protein (Bax) and phosphorylated p53 (p-P53) protein expression while elevating B-cell lymphoma 2 (Bcl2) protein expression. Conclusion: These findings suggest that C. auriculatum effectively delays reproductive function decline in the testicular tissues of naturally aging rats, likely by inhibiting DNA damage, modulating the P53 signaling pathway, and reducing reproductive cell apoptosis.