EFFECT OF EPICATECHIN AND NALOXONE ON CARDIO‐PROTECTIVE PHENOTYPE

Epicatechin is a well know antioxidant linked with varieties of protective effects in both humans and animals. However, a receptor mediated effect has not been proposed. We tested the hypothesis that epicatechin mediates cardioprotection via opioid receptor activation. Mice were randomly assigned to the following four groups: control, epicatechin, naloxone, and epicatechin+naloxone. Epicatechin was administered by oral gavage daily (1mg/kg) for 10 days. Naloxone was administered by intraperitioneal injection daily (5mg/kg) for 10 days. Whole heart homogenates were assayed for the opioid downstream targets. Epicatechin induced a protective phenotype in mice by increasing the p‐SRC, p‐AKT, p‐ IkBa, and by decreasing JNK, and CAD expression. Naloxone administration withdrew the protective effect of epicatechin. Epicatechin‐induced protective phenotype was blocked by naloxone. Blocking the opioid receptor with naloxone abolished the protective phenotype and cardioprotective effect provided by epicatechin. These data suggest that epicatechin acts via opioid receptor.