Green tea is a popularly consumed beverage worldwide and contains polyphenols, whose antioxidant activities could improve sperm parameters and fertility thereof. We investigated the effect of green tea on the male rat reproductive system as well as its safety. Male Wistar rats were administered 2 and 5% aqueous extract of green tea for 52 days’ ad libitum, while the control group received tap water. Total polyphenol, flavanol, flavonol and soluble solids significantly increased in a concentration-dependent manner in vitro (P < 0.01). Weights of body, testis, epididymis, prostate gland, seminal vesicles, and liver, serum levels of testosterone, ferric reducing antioxidant power, creatinine, and sperm motility, remained unchanged (P > 0.05). Kidney weight, sperm concentration and vitality, spontaneous acrosome reaction increased (P < 0.05), while alanine transaminase and aspartate transaminase levels decreased (P < 0.05). Catalase, superoxide dismutase, glutathione and lipid peroxidation remained unchanged in the testes, liver and kidney (P > 0.05). Histological sections of testis, epididymis, kidney and liver showed no conspicuous alteration. Diameter and epithelial height of seminiferous tubule decreased, while caudal epididymis epithelial height increased (P < 0.01). Consumption of green tea in the conditions used in the present study seems to be safe and improved sperm parameters. However, subtle structural changes observed in the decreased diameter and epithelial height of the seminiferous tubule and increased acrosome reaction needs further investigation.

绿茶是世界范围内普遍饮用的饮料，含有多酚，其抗氧化活性可以改善精子参数和生育能力。我们研究了绿茶对雄性大鼠生殖系统的影响及其安全性。雄性 Wistar 大鼠随意服用 2% 和 5% 的绿茶水提取物，持续 52 天，而对照组则接受自来水。在体外，总多酚、黄烷醇、黄酮醇和可溶性固形物以浓度依赖性方式显着增加（P  < 0.01）。身体、睾丸、附睾、前列腺、精囊和肝脏的重量、血清睾酮水平、降低抗氧化能力的铁、肌酐和精子活力保持不变（P > 0.05）。肾脏重量、精子浓度和活力、自发性顶体反应增加（P  < 0.05），而丙氨酸转氨酶和天冬氨酸转氨酶水平下降（P < 0.05）。过氧化氢酶、超氧化物歧化酶、谷胱甘肽和脂质过氧化在睾丸、肝脏和肾脏中保持不变（P  > 0.05）。睾丸、附睾、肾脏和肝脏组织切片未见明显改变。曲细精管直径和上皮高度减少，附睾尾端上皮高度增加（P < 0.01)。在本研究中使用的条件下饮用绿茶似乎是安全的，并且可以改善精子参数。然而，在生精小管直径和上皮高度减小以及顶体反应增加中观察到的细微结构变化需要进一步研究。