ABSTRACT
Green tea, prepared from the steamed and dried leaves of the shrub Camellia sinensis, is known for its antioxidant and anti-carcinogenic effects. However, its effects on male gonadal functions have not been explored adequately and the present investigation has been undertaken to evaluate the effect of green tea extract on gonads of adult male albino rats. Results of in vivo studies showed that green tea extract (GTE) at mild (1.25 g%, ≡ 5 cups of tea/day), moderate (2.5 g%, ≡ 10 cups of tea/day) and high (5.0 g%, ≡ 20 cups of tea/day) doses, for a period of 26 days, altered morphology and histology of testis and accessory sex organs. A significant dose-dependent decrease in the sperm counts, inhibited activities of testicular ∆53- and 17-hydroxysteroid dehydrogenase (∆5-3-HSD and 17-HSD respectively) and decreased serum testosterone level were noticed. Significant increase in serum LH level was observed after moderate and high doses; serum FSH level also increased but not significantly. Histopathological examination showed inhibition of spermatogenesis evidenced by preferential loss of matured and elongated spermatids. Results of this study showed that GTE at relatively high dose may cause impairment of both the morphological and normal functional status of testis in rodents and thus its consumption at relatively high doses raises concern on male reproductive function in spite of its other beneficial effects.
ABSTRACT
Free radicals are all known to damage cell components. The present study was designed to evaluate the free radical generation in the testis and liver and also to determine the testicular and hepatic antioxidant enzyme activities with and without catechin administration in thyroxine induced male Sprague-Dawley rats. The experimental animals were divided into four groups, six on each division. L-thyroxine (T4) (0.3 mg/kg body weight) was administered to experimental groups for 15 days. Another group (CAT-T4) was administered with L-thyroxine (T4) in the dose as mentioned and catechin (100mg/kg of body weight/day) simultaneously. Third group was administered only with catechin, and the remaining group was kept as control. Lipid peroxidation level (LPO) increased in L-thyroxine treated rats as compared to control, while LPO level was almost normal in L-thyroxine (T4) and catechin (CAT-T4) treated group. Superoxide dismutase (SOD) and catalase activities were increased in L-thyroxine (T4) treated rats as compared to control, where as there were almost at normal level in L-thyroxine (T4) and catechin (CAT-T4) treated groups. The results show that, thyroxine administration develops oxidative stress; the organism defends it against the effects of oxidative stress by increasing SOD and catalase activities as a protective mechanism and catechin, being an antioxidant, normalizes lipid peroxidation in testis and liver including SOD and catalase activities.