Effects of Rubus coreanus on sperm parameters and cAMP-responsive element modulator (CREM) expression in rat testes

Rubi Fructus (RF), the dried, unripe fruit of Rubus coreanus MIQ. (Rosaceae), has been used to improve male reproductive function in traditional Korean medicine. In this study, we investigated the effects of RF on sperm parameters and expression of cAMP-responsive element modulator (CREM), which has a crucial role in spermatogenesis. RF was administered to 8-week-old male Wistar rats for 56 consecutive days (1.0 g/kg, daily, p.o.). Sperm analysis, RT-PCR, and Western blot assays were then carried out. The RF-treated animals showed significant increases in the weight of the testes, epididymal sperm count, and sperm motility compared to the control group. RF also increased the expression of CREM at both the mRNA and protein levels. These results suggest that RF may improve male fertility by enhancing spermatogenesis.