title: Genotoxic effects of green tea extract on human laryngeal carcinoma cells in vitro.
abstract: Green tea (Camellia sinensis) contains several bioactive compounds which protect the cell and prevent tumour development. Phytochemicals in green tea extract (mostly flavonoids) scavenge free radicals, but also induce pro-oxidative reactions in the cell. In this study, we evaluated the potential cytotoxic and prooxidative effects of green tea extract and its two main flavonoid constituents epigallocatechin gallate (EGCG) and epicatechin gallate (ECG) on human laryngeal carcinoma cell line (HEp2) and its cross-resistant cell line CK2. The aim was to see if the extract and its two flavonoids could increase the sensitivity of the cisplatin-resistant cell line CK2 in comparison to the parental cell line. The results show that EGCG and green tea extract increased the DNA damage in the CK2 cell line during short exposure. The cytotoxicity of EGCG and ECG increased with the time of incubation. Green tea extract induced lipid peroxidation in the CK2 cell line. The pro-oxidant effect of green tea was determined at concentrations higher than those found in traditionally prepared green tea infusions.
authors.affiliation: Food Technology and Biotechnology, Zagreb, Croatia. kdurgo@pbf.hr
authors.forename: Ksenija
authors.initials: K
authors.lastname: Durgo
authors.forename: Sandra
authors.initials: S
authors.lastname: Kostić
authors.forename: Katarina
authors.initials: K
authors.lastname: Gradiški
authors.forename: Draženka
authors.initials: D
authors.lastname: Komes
authors.forename: Maja
authors.initials: M
authors.lastname: Osmak
authors.forename: Jasna
authors.initials: J
authors.lastname: Franekić
mesh_terms: D028241:Camellia sinensis; D002392:Catechin / Q000031:analogs & derivatives / Q000633:toxicity; D045744:Cell Line, Tumor / Q000187:drug effects; D020552:Comet Assay; D004249:DNA Damage / Q000187:drug effects*; D006801:Humans; D007822:Laryngeal Neoplasms / Q000235:genetics*; D015227:Lipid Peroxidation / Q000187:drug effects; D009153:Mutagens / Q000633:toxicity; D010936:Plant Extracts / Q000633:toxicity*; D013662:Tea; D014407:Tumor Cells, Cultured / Q000187:drug effects
chemical_list: D009153:Mutagens; D010936:Plant Extracts; D013662:Tea; D002392:Catechin; C062669:epicatechin gallate; C045651:epigallocatechin gallate