Phenolic compounds, particularly flavonoids, from plant sources have long been observed to have antioxidant activity with potential benefits for human health. EGCG is a principle phenolic antioxidant found in a variety of plants, including green and black tea. EGCG inhibits cellular oxidation of low density lipoproteins. EGCG is readily detected in human and rat plasma at ng/ml levels following oral ingestion. ECGC inhibits the peroxynitrite-induced formation of the oxidative injury markers 8-hydroxy-2-deoxy guanosine and 3-nitrotyrosine.