Effects of soaking temperature and soaking time during preparation of water extract of tea on anticlastogenicity against environmental tobacco smoke in the sister-chromatid exchange assay

Water extract of tea (WET) was prepared by soaking green tea at different t emperatures for various periods of time and was used to test whether the so aking temperature and soaking time during the preparation of WET influence the content of polyphenols and the anticlastogenicity of WET against enviro nmental tobacco smoke (ETS). Five major polyphenols in WET were measured. E xtractable-respirable particulate (ERP) was obtained from ETS-contaminated indoor air (ERP-ETS). The sister-chromatid exchange assay (SCE) was utilize d to evaluate the clastogenic effects of ERP-ETS and the anticlastogenic ef fects of WET. The results indicate that ERP-ETS is clastogenic and WET has significant anticlastogenic effects on ERP-ETS. The content of polyphenols and the anticlastogenic potential of WET depended on the soaking temperatur e and soaking time during WET preparation. At the soaking temperature of 80 degrees C, an increased soaking time was correlated with a higher percenta ge of polyphenols and a concomitantly enhanced anticlastogenic efficacy. By contrast, at the soaking temperature of 100 degrees C, a longer soaking ti me was associated with a higher percentage of polyphenols concomitant with a lower anticlastogenic efficacy. The data suggest that, besides polyphenol s, and additional material(s), which may be partially inactivated at 100 de grees C, is contributing to the anticlastogenicity of WET. (C) 2000 Elsevie r Science Ireland Ltd. All rights reserved.