Hafezeh Davari - Department of Biology, Faculty of Sciences, Ferdowsi University of Mashhad, Iran
Farhang Haddad - Department of Biology, Faculty of Sciences, Ferdowsi University of Mashhad, Iran
Ali Moghimi - Department of Biology, Faculty of Sciences, Ferdowsi University of Mashhad, Iran
Mohammad Farhad Rahimi - Department of Physics, Faculty of Sciences, Ferdowsi University of Mashhad, Iran
Mohammad Reza Ghavamnasiri - Cancer Research Centre (CRC), Department of Radiation Oncology, Omid Hospital, Mashhad University of Medical Science, Mashhad, Iran

Objective(s)The aim of this study was to investigate the radioprotective effect of green tea against genotoxicity induced by gamma irradiation in cultured blood lymphocytes from ۵ human volunteers.Materials and MethodsPeripheral blood samples were collected from volunteers before and ۱, ۳ and ۵ hr after drinking a decoction ۴ g green tea in ۲۸۰ ml boiling water for ۵ constitutive days with the same quantity. At each time point, the whole blood samples were exposed to ۲۰۰ cGy of ۶۰ Co gamma irradiation and then were cultured with mitogenic stimulation to determine the chromosomal aberration in micronucleus assay on cytokinesis-blocked binucleated cells.ResultsAs expected, for each volunteer, the results showed a significant increase in the incidence of micronuclei after exposure to gamma irradiation as compared to non-irradiated control samples. Only lymphocytes blood sample collected ۳ hr after drinking green tea exhibited a significant decrease in incidence of micronuclei compared to non-treated irradiated samples.ConclusionThese results suggest the radioprotective ability of green tea against ionizing radiation in human lymphocytes, at specified time after consumptior.

Gamma irradiation, green tea, Lymphocytes, Micronucleus, Natural radioprotective