title: The usefulness of cytogenetic parameters, level of p53 protein and endogenous glutathione as intermediate end-points in raw betel-nut genotoxicity.
abstract: Betel-nut (BN) chewing related oral mucosal lesions are potential hazards to a large population worldwide. Genotoxicity of betel alkaloids, polyphenol and tannin fractions have been reported. It has been shown earlier that BN ingredients altered the level of endogenous glutathione (GSH) which could modulate the host susceptibility to the action of other chemical carcinogens. The north-east Indian variety of BN, locally known as 'kwai', is raw, wet and consumed unprocessed with betel-leaf and slaked lime and contains higher alkaloids, polyphenol and tannins as compared to the dried one. Therefore, the purpose of this study was to investigate the extent of DNA damage, pattern of cell kinetics, the level of p53-protein and endogenous GSH in kwai chewers in the tribal population of Meghalaya state in the northeastern region of India with an aim to see whether these end-points could serve as biomarkers of genetic damage of relevance for genotoxic/carcinogenic process. The present data show higher DNA damage, delay in cell kinetics, p53 expression and lower GSH-level in heavy chewers (HC) than nonchewers (NC). The influence of bleomycin (BLM) on chromatid break induction in G2-phase of peripheral blood lymphocytes in NC and HC has been analysed to determine individual susceptibility to carcinogenic assaults. HC showed higher induction of chromatid breaks than NC. Risk assessment in this study suggests an interaction between carcinogen exposure and mutagen sensitivity measures, risk estimates being higher in those individuals who both consume kwai and express sensitivity to free radical oxygen damage in vitro. From this study it seems that besides cytogenetical parameters, the level of endogenous GSH and the level of p53 protein could act as effective biomarkers for kwai chewers.
authors.affiliation: Genetics Laboratory, Department of Zoology, North-Eastern Hill University, Shillong-793022, India.
authors.forename: K
authors.initials: K
authors.lastname: Kumpawat
authors.forename: A
authors.initials: A
authors.lastname: Chatterjee
mesh_terms: D000328:Adult; D000368:Aged; D001114:Areca / Q000633:toxicity*; D015415:Biomarkers / Q000032:analysis; D002453:Cell Cycle; D002478:Cells, Cultured; D020732:Cytogenetic Analysis; D004249:DNA Damage; D023381:Endpoint Determination; D005260:Female; D005978:Glutathione / Q000096:biosynthesis / Q000097:blood / Q000378:metabolism*; D006801:Humans; D007194:India; D008297:Male; D008409:Mastication; D008875:Middle Aged; D009152:Mutagenicity Tests / Q000379:methods; D009153:Mutagens / Q000633:toxicity*; D018515:Plant Leaves / Q000633:toxicity; D016159:Tumor Suppressor Protein p53 / Q000096:biosynthesis* / Q000235:genetics
chemical_list: D015415:Biomarkers; D009153:Mutagens; D016159:Tumor Suppressor Protein p53; D005978:Glutathione