RESUMO
BACKGROUND: Green tea (Camellia sinensis), which is the most common drink across the world after water, has many antioxidant properties. Epigallocatecin-3-gallate (EGCG) is a flavonoid which accounts for 33-50% of green tea solids. It functions as a powerful antioxidant, preventing oxidative damage in healthy cells, with antiangiogenic and antitumor activities and as a modulator of tumor cell response to chemotherapy. Malathion is an organophosphate pesticide which is widely used in agriculture, veterinary and industries. Oxidative stress has been identified as one of malathion's main molecular mechanisms. The purpose of this study was to evaluate protective role of EGCG against malathion induced genotoxicity using human lymphocyte model. Blood samples from 8 non-smoker healthy volunteers with no history of chemotherapy were collected and divided into six groups: Control, EGCG (50 µM), EGCG (20 µM), Malathion (24 µM), EGCG (50 µM)+Malathion (24 µM) and EGCG (20 µM)+Malathion (24 µM). For genotoxicity assay, we employed micronuclei test. For antioxidant capacity evaluation, GSH content and MDA levels were measured. Malathion showed significant genotoxic damage compared to the intact lymphocytes, however, treatment with EGCG at both concentrations were reduced the genotoxic effect of malathion. Malathion induced lipid peroxidation, while pre-treatment with EGCG at both concentrations, significantly protected the lymphocytes against malathion induced lipid peroxidation. Malathion significantly reduced GSH content, but pre-treatment with EGCG significantly recovered GSH content. Overall this study demonstrated that EGCG (at both concentrations) significantly prevents human lymphocytes against malathion induced genotoxicity and oxidative damage.
