Effects of anthocyanin extracted from black soybean seed coat on spermatogenesis in a rat varicocele-induced model

Varicocele is the most common cause of primary male infertility and is associated with oxidative stress. The aim of the present study was to investigate the effects of anthocyanin on a rat model of varicocele. Twenty-four male rats were divided into four experimental groups: a normal control group, a varicocele-induced control group and two varicocele-induced groups treated with either 40 or 80mgkg(-1), p.o., anthocyanin for 4 weeks. Varicocele was induced by the partial obstruction of the left renal vein. After 8 weeks, the testes and epididymides from rats in all groups were removed, weighed and subjected to histological examination and semen analysis. Apoptosis in the testes was determined by terminal deoxyribonucleotidyl transferase-mediated dUTP-digoxigenin nick end-labelling (TUNEL) and oxidative stress was assessed by measuring 8-hydroxy-2'-deoxyguanosine (8-OHdG) levels. Although no significant differences in sperm counts were observed among the groups, anthocyanin treatment of the varicocele-induced groups resulted in significantly increased testes weight, sperm motility and spermatogenic cell density (P<0.05). Anthocyanin treatment also significantly decreased apoptotic body count and 8-OHdG concentrations (P<0.05). We suggest that the antioxidant effect of anthocyanin prevented the damage caused by varicocele-induced reactive oxygen species.