Epigallocatechin-3-gallate (EGCG), the major polyphenol from green tea, has the potential to impact a variety of human diseases. EGCG functions as a powerful antioxidant, preventing oxidative damage in healthy cells, but also as an antiangiogenic and antitumor agent and as a modulator of tumor cell response to chemotherapy. It was shown, that EGCG can inhibit 5-cytosine DNA methyltransferase (DNMT) activity and reactivate methylation-silenced genes in cancer cells and another of the probable mechanisms by EGCG exercise their anti-tumor property is through the suppression of the NFκB signaling pathway. EGCG has emerged as a potential neuroprotective agent for the treatment of neurological disorders associated with harmful effects of reactive oxygen species. The neuroprotective mechanism of action is probably based on several factors, including EGCG's modulation of several signal transduction pathways, its influence on the expression of genes regulating cell survival or programmed cell death, as well as its modulation of mitochondrial function. A phase II/III trial of oral Sunphenon epigallocatechin-3-gallate in patients with progressive multiple sclerosis has been completed. In addition, EGCG was in phase III clinical trials for the treatment of multiple system atrophy and for patients with Duchenne Muscular Dystrophy ((DMD). DMD is the most frequent neuromuscular condition to occur in childhood and youth.