Protection of dystrophic muscle cells with polyphenols from green tea correlates with improved glutathione balance and increased expression of 67LR, a receptor for (−)‐epigallocatechin gallate

Duchenne muscular dystrophy (DMD) is a fatal muscle wasting disease caused by the absence of the protein dystrophin. Because oxidative stress contributes to the pathogenesis of DMD, we investigated if a green tea polyphenol blend (GTP) and its major polyphenol (−)‐epigallocatechin gallate (EGCg), could protect muscle cell primary cultures from oxidative damage induced by hydrogen peroxide (H 2 O 2 ) in the widely used mdx mouse model. On‐line fluorimetric measurements using an H 2 O 2 ‐sensitive probe indicated that GTP and EGCg scavenged peroxide in a concentration‐dependent manner. A 48 h exposure to EGCg increased glutathione content but did not alter the expression of proteins involved in membrane stabilization and repair. Pretreatment of dystrophic cultures with GTP or EGCg 48 h before exposure to H 2 O 2 improved cell survival. Normal cultures were protected by GTP but not by EGCg. 67LR, a receptor for EGCg, was seven times more abundant in dystrophic compared with normal cultures. Altogether our results demonstrate that GTP and EGCg protect muscle cells by scavenging H 2 O 2 and by improving the glutathione balance. In addition, the higher levels of 67LR in dystrophic muscle cells compared with normal ones likely contribute to EGCg‐mediated survival. © 2009 International Union of Biochemistry and Molecular Biology, Inc.