Mechanisms of green tea in the prevention of oral cancer in smokers Fung-Lung Chung, Joel Schwartz, Chris Herzog, Yang-Ming Yang, Victoria Baker, Eric Larios, Nomar Bodon. Institute for Cancer Prevention, Valhalla, NY. Studies in rodents and in cultured cells have provided evidence supporting the role of green tea in the prevention of various cancers. However, epidemiological studies have so far generated inconsistent data regarding consumption of tea and reduced risk of human cancers. In order to verify the laboratory studies, we carried out studies to examine the mechanisms of tea in the prevention of human cancer using oral cells in smokers as a model. This is based on results of an intervention trial showing tea polyphenols prevents the development of preneoplastic lesions of oral tissue in smokers (Li et al, Proc. Soc. Exp. Biol. Med.1999). In this study, we investigated the molecular and cellular effects in oral cells of smokers after green tea consumption. Three smokers who do not drink tea were recruited for a 4-week treatment period. Each subject was asked to consume 5 cups of green tea daily, each cup containing 400 mg of green tea total extract. Oral cells were collected once a week, one week before (baseline) and during the tea treatment, using a nylon bristle cytobrush and stored at -80° C until use. The cells were divided into portions for assays, including benzo(a)pyrene (BaP)-DNA adduct by immunohistochemical staining, enal-derived cyclic adducts by 32postlabeling/HPLC assay, p53 by immunohistochemical staining and gel shift assay, p21 by RT-PCR, and apoptosis by Mebstain assay. The results showed a general trend of increasing apoptosis as the green tea treatment progressed. The increased apoptosis was concomitant with an increase in p53 and p21 activity in the oral cells. Interestingly, the BaP- and acrolein-DNA adducts also showed a trend of decreasing levels in the oral cell DNA of smokers during green tea treatment. These studies provide initial evidence suggesting that green tea can induce apoptosis in oral cells of smokers, possibly via the activating p53 and its effector gene. We are currently expanding the study by recruiting more smokers as well as non-smokers. AACR Abstract Number: 4803, 2003 Ann's NOTE: The following abstracts also examined green tea, surely one of the MOST EXAMINED substance in the 'natural' area: #4793, #4794, #4795, #4796 ,#4797, #4798, #R4800, #4802, #5607. Remember we are NOT Doctors and have NO medical training. This site is like an Encylopedia - there are many pages, many links on many topics. Support our work with any size DONATION - see left side of any page - for how to donate. You can help raise awareness of CAM.