Planta Med 2013; 79 - PB30
DOI: 10.1055/s-0033-1351975

In vivo effects of green and black tea on the rat male reproductive system

CS Opuwari 1, TK Monsees 1
  • 1University of the Western Cape, Dept. of Medical Biosciences, Bellville 7535, Republic of South Africa

Green (unfermented, GT) and black (fermented, BT) tea (Camellia sinensis) may improve male reproductive functions due to their high level of antioxidants. In this study, Male rats received GT or BT (2% or 5%, 5 min brewed) as sole source of drinking for 52 d in order to investigate the effect on the male reproductive system. Chemical analysis showed that GT had higher levels of soluble solids (SS), total polyphenol (33.3 vs. 25.9% of SS for BT) and flavanol (29.5 vs. 6.1% of SS for BT) while BT contains more flavonol. Both teas had no significant effect on serum antioxidant capacity, body weight gain, relative weight of reproductive organs and liver. However, the 5% teas increased relative kidney weight and creatinine activity. In contrast, activities of liver markers, ALT and AST, were significantly reduced. Testis showed mainly a normal spermatogenesis, although a significant decrease in the tubule diameter and germinal epithelial height was noticed. Also, GT and BT significantly increased epithelial height of the epididymis. Epididymal sperm concentration was significantly increased after GT treatment. Both teas significantly enhanced sperm viability and total motility. In addition, 2% black tea also significantly raised progressive sperm motility. GT and BT treated groups displayed a significant increase in spontaneous acrosome reaction from 5.25% to 12% and 14%, respectively. Serum testosterone level showed a significant concentration-dependent increase from 5.3 to 8.73 ng/ml after exposure to GT. In contrast, black tea lowered testosterone levels to 3.2 ng/ml. In conclusion, green and black tea significantly improved sperm concentration, viability and motility. This is beneficial for male fertility and might be due to the high level of antioxidants. However, the increased level of acrosome reaction might be a reason for concern as this would inhibit the fertilization process. Intake of large amounts of GT or BT may also impair kidney function.