Protective effects of black tea extract on testosterone induced oxidative damage in prostate

Since ancient times, antipyretic, anti-inflammatory, antimicrobial and antioxidative properties of tea have been recognized. Black tea (Camellia sinensis) contains a variety of polyphenolic ingredients including the theaflavins (TF), thearubigins (TG) and catechins. Components from black tea have been accounted to play an important role in scavenging free radicals generated by mutagens and carcinogens. Androgens are the key factors in either the initiation or progression of prostate cancer (PCA) by inducing oxidative stress. In the present set of investigations, the antioxidative potential of black tea extract against androgen mediated oxidative stress in male Wistar rats has been studied. Testosterone was given at a dose of 5 mg/kg b.w. subcutaneously, consecutively for 5 days. Prior to androgen administration, animals were kept on 0.5, 1.0 and 1.5% aqueous tea extract (ATE) as sole source of drinking fluid for 15 days. The prostate tissue was dissected out for biochemical analysis for antioxidant enzymes viz. catalase (CAT), superoxide dismutase (SOD), lipid peroxidation (LPO), glutathione-s-transferase (GST) and glutathione reductase (GR). The results revealed that testosterone administration induced the oxidative stress in rat prostate, however, in 0.5, 1.0 and 1.5% ATE supplemented groups, a significant protective effect of black tea against testosterone induced oxidative injury was recorded. Hence, the study reveals that constituents present in black tea impart protection against androgen induced oxidative injury that may result in development of prostate cancer. (C) 2004 Elsevier Ireland Ltd. All rights reserved.