Sericin improves age-related copulatory impairment in rats through testosterone enhancement and PI3K/Akt/eNOS signaling modulation

Abstract

Purpose Impaired sexual behavior associated with aging remains a significant global health concern. Studies are investigating natural compounds to identify effective interventions for counteracting this condition. The present study examined the effectiveness of sericin (Ser) on age-related sexual impairment in aged rats. Methods A total of 10 young adult and 40 aged male Wistar rats were used. The aged animals were categorized into four groups and received NS or Ser at doses of 200, 250, and 300 mg/kg for 30 consecutive days. Copulatory behavior was assessed to evaluate sexual function. At the end of the behavioral assessment, serum testosterone levels, penile p-PI3K/PI3K, p-Akt/Akt, p-eNOS/eNOS, and p-NF-κB/NF-κB ratios, oxidative stress markers (TAC, MDA, GPx, and SOD), as well as cGMP, NO, IL-6 and TNF-α levels were measured. Notably, biochemical evaluations (n = 6/group) and Western blotting (n = 3/group) were conducted on representative subsets. Results The results demonstrated that Ser improved copulatory behavior in aged animals. The enhancement in sexual behavior was associated with increased PI3K/Akt/eNOS signaling and restoration of the NO/cGMP pathway, elevated testosterone levels, reduced lipid peroxidation, increased TAC and antioxidant enzyme activities, as well as diminished penile levels of IL-6 and TNF-α in aged rats. Conclusion These findings suggest that the ability of Ser to attenuate oxidative stress and inflammation may represent a promising approach for restoring testosterone levels and PI3K/Akt/eNOS signaling, thereby alleviating age-related sexual dysfunction. Nevertheless, further studies are required to clarify the mechanisms and evaluate therapeutic potential of Ser in the management of sexual dysfunction associated with aging.

Keywords: Aging, Copulatory behavior, PI3K/Akt/eNOS pathway, Rat, Sericin, Testosterone