Protective Effect of Green Tea Against Dimethylnitrosamine Induced Genotoxicity in Mice Bone Marrow Cells

Abstract

Cancer is a major cause of death in the world; thus, the prevention of this disease would have a significant impact on public health. Chemoprevention is defined as natural and synthetic pharmacological (chemical) agent to disrupt the process of carcinogenesis. Green tea is a potent chemopreventive agent in many test systems and has been shown to inhibit tumor promotion and induce apoptosis. It is one of the most frequently consumed beverages in the world. Green tea polyphenolics have demonstrated antimutagenic, anticarcinogenic, antioxidant and antipromotional effects. The aim of this work is to study the protective effect of green tea extract against genotoxic damage of dimethylnitros- amine (DMN) in mice bone marrow cells. Our results demonstrated that the administration of green tea extract 24 hr before the DMN injection significantly suppressed DMN-induced chromosomal aberrations and sister chromatid exchanges. The suppression was observed 18 hr, 24 hr and 48 hr after the DMN treatment but no suppressive effect was observed at the early period (6 hr and 12 hr) after the DMN treatment. Furthermore, the suppression was observed in all doses of DMN (4, 5 and 6 mg/kg) investigated. Mice were given green tea 2 hr before the DMN injection displayed no suppressive effect. Mice were given 2% green tea extract as the sole source of drinking water for four days before sacrifice displayed significantly suppressed DMN-induced chromosomal aberrations and sister chromatid exchanges. We conclude that green tea presents significant antigenotoxic concern under the anticipated conditions of use. These results are consistent with other antigenotoxicity studies of green tea.