193-8 Shukla

Black tea is one of the most popular natural beverages, which is consumed by the majority of the world population. Tea consumption has been reported to inhibit to tumor formation in various experimental and epidemiological studies (Katiyar and Mukhtar, 1996). Tea ingredients inhibit N-nitrosomethyl benzylamine, diethylnitrosoamine and polycyclic aromatic hydrocarbon induced esophageal, lung and mammary tumorigenesis (Rogers et al, 1988; Li, et al 1999; Shukla and Taneja 2002). Besides this, the polyphenolic ingredients of black tea extract have been reported to inhibit 7,12-dimethylbenzanthracene (DMBA) and ultraviolet B light induced skin and transplantable tumors (Hakim et al, 2002; Javed and Shukla, 2000; Lu, et al, 1997). Antimutagenic effects of green and black tea have been identified towards several mutagens in various mammalian and microbial test systems (Apostolides, 1997; Mukherjee et al, 1997; Okai and Higashi, 1997; Shukla and Taneja, 2001) Black tea contains a variety of polyphenolic ingredients including theaflavins (TF), thearubigins, (TG) epigallocatechin-3-gallate (EGCG), epicatechin (EC), epicatechin gallate (ECG) and epigallocatechins (EGC) in addition to some amount of caffeine and proteins (Graham, 1992). EGCG has been reported to scavenge free radicals generated by benzo(a)pyrene (BaP), DMBA and nitrosamines (Dreosti et al, 1997; Sano et al, 1995; Sarkar and Bhaduri, 2001). TF, the major polyphenolic component of black tea is also known to possess antioxidant effects (Feng et al, 2002; Shiraki et al, 1994). The present set of investigations were conducted to examine the antimutagenic potential of black tea extract and polyphenols towards BaP and CP in the Salmonella typhimurium reverse mutation assay.