In vivo effects of black tea on the male rat reproductive system and functions of the kidney and liver.

This study focused on the effects of black tea on the male reproductive system as well as the kidney and liver functions. Male Wistar rats were given aqueous extract of black tea (2% and 5%) for 52 days as the only means of drinking fluid, while control rats received tap water. Black tea enhanced sperm vitality (44%-49%), total sperm motility (10%-12%) and acrosome reaction (2%-9%) (p < .05). Body weight gain, testis, epididymis, seminal vesicles, prostate, liver weight, testosterone level, sperm concentration, ferric reducing antioxidant power (FRAP) and antioxidant levels in the testes, liver and kidney remained unchanged (p > .05). Black tea (5%) increased kidney weight (p < .05). Testis and epididymis showed normal histological appearance. However, black tea significantly reduced the diameter (9%-10%) and epithelial height (9%-10%) of the seminiferous tubule, but increased the epithelial height of the cauda epididymis (8%-24%) (p < .05). A significant reduction in serum levels of alanine aminotransaminase (ALT) (38%) and aspartate aminotransaminase (AST) (23%-34%) was observed (p < .05); creatinine level, on the other hand, increased (8%-72%) (p < .05). Black tea improved several sperm parameters, but may cause subtle changes in certain reproductive organs and the kidney functions.