INHIBITORY EFFECT OF ROOIBOS TEA (ASPALATHUS-LINEARIS) ON THE INDUCTION OF CHROMOSOME-ABERRATIONS IN-VIVO AND IN-VITRO

The treatment of Chinese hamster ovary cells with Rooibos tea extract (RT, lyophilizate of Rooibos tea infusion, 100-1000 mu g/ml) simultaneously with or subsequent to mitomycin C or benzo[a]pyrene (BP) significantly suppressed chromosome aberrations induced in the presence or absence of a metabolic activation system. Furthermore, gastric intubation of RT (0.05-0.1%) to ICR male mice at 1 ml per mouse per day for 28 days before intraperitoneal mitomycin C or BP treatment reduced micronucleus induction in peripheral blood reticulocytes. When mice received oral administration of RT (0.05%) in the drinking water ad libitum for 28 days, the frequency of micronuclei induced by mitomycin C (i.p.) or gamma rays was also decreased. As the dose of tea extract used in the experiments was almost the same as that of typical human daily consumption, RT intake might be a useful tool for chemoprevention of human cancer.