The orexinergic system mediates the effects of ginsenoside Rg1 on cyclophosphamide-induced reproductive toxicity.

Cyclophosphamide (CP) is a widely prescribed chemotherapeutic and immunosuppressive agent known to cause significant reproductive toxicity. Ginseng effectively counteracts CP-induced reproductive toxicity, exhibiting pharmacological effects that resemble enhanced orexin signaling. In this study, molecular docking identified ginsenoside Rg1 as the candidate with the highest binding affinity for orexin receptor 1 (OX1R). In CP-treated male mice, Rg1 dose-dependently ameliorated reproductive toxicity, as evidenced by improved sexual behavior, sperm motility and DNA integrity, serum testosterone levels, and testicular histology. These protective effects were significantly attenuated by co-administration of the OX1R antagonist SB-334867. Notably, serum orexin-A levels did not differ significantly across all experimental groups, indicating that Rg1 acts directly on testicular OX1R rather than by elevating circulating orexin-A. Mechanistically, Rg1 restored testicular PI3K/AKT phosphorylation in an OX1R-dependent manner and preserved glucose transporter 3 and glucose transporter 8 immunoreactivity in germ cells. These findings demonstrate that Rg1 protects against CP-induced reproductive toxicity through OX1R-dependent activation of the PI3K/AKT pathway and maintenance of glucose transporter-mediated metabolism. Thus, OX1R represents a crucial mechanistic node and Rg1 is a promising adjunct therapy to mitigate chemotherapy-related male infertility.