Protective effects of epigallocatechin-3-gallate against lead-induced oxidative damage.

A positive association of lead exposure with clinical cardiovascular outcomes has been identified. Epigallocatechin-3-gallate (EGCG) is one of the active polyphenols in green tea, it has not been reported as an antioxidant against lead toxicity. This study was carried out to investigate whether EGCG could protect the ventricular myocytes of rats against lead-induced oxidative damage. Isolated ventricular myocytes were exposed to lead and/or EGCG, then activities of superoxide dismutase (SOD), catalase (CAT), and malondialdehyde (MDA) and the levels of hydroxyl radical (OH(·)), hydrogen peroxide (H(2)O(2)), and superoxide anion (O(2) (·-)) were measured. The results showed that lead induced a significant decrease of SOD and CAT activities, while the levels of MDA increased significantly. Increases in intracellular OH(·), O(2) (·-), and H(2)O(2) were found as well. These processes were concentration-dependent and statistically significant different when compared to 2.0 µM lead exposure. The activity of SOD and CAT increased while the levels of MDA and reactive oxygen species (ROS) decreased after treatment with EGCG. While there were progressive benefits with increasing EGCG concentrations, there was no statistical significance at a 30 µg/mL dose when compared with the control. These results will provide more evidence for lead toxicity to tissue, cell, and biological macromolecule.