The Protective Effect Of EGCG On Cadmium-induced Cytotoxicity In Liver Cells Of Normal Human

The present study aims to investigate the protective effect and potential mechanism of epigallocatechin gallate (EGCG) on Cd-induced cytotoxicity in normal human liver cell (HL-7702). The cytotoxicity of cadmium and the protective effect of EGCG on normal human liver cell were assessed by using MTT assay; apoptosis was shown by using Hoechst33258 staining and agarose gel electrophoresis; changes in intracellular ROS (Reactive Oxygen Species) production were detected by using fluorescent dyes (DCFH-DA); the formation of chelate between EGCG and the cadmium ion was investicated by using UV-visible detection of wide-band scan (UV-Vis) and nuclear magnetic resonance hydrogen spectrum. The results are as follows:1. HL-7702 cells viability decreased significantly (P<0.05) by Cd, and Hoechst33258 staining and agarose gel electrophoresis experiments showed that cadmium induced the induction of DNA fragments and apoptosis.2. Significant elevation of cell viability was observed after the cells were pre-treated (80μM) for 48 h incubating with EGCG at 50,100,200 uM for 3 h respectively. The repair rates were 13.8%,33.9%and 71.4%respectively. Furthermore, EGCG could decreased the intracellular ROS level significantly(P< 0.01).3.EGCG might combining with Cd2+forming Cd2+-EGCG complex.The present result suggested that EGCG could reduce Cd-induced cytotoxicity in HL-7702 cells directly by decreasing the intracellular ROS level.