Cardioprotective effects of epicatechin in ischemia‐reperfusion (IR) injury

Abstract

Epidemiological studies have shown a correlation between flavonoid‐rich diets and improved cardiovascular prognosis. Cocoa contains large amounts of flavonoids, in particular flavanols (mainly catechins and epicatechins). Flavonoids possess various properties that may confer protective effects to tissues in the setting of injury. We examined the abiliy of epicatechin to reduce short term IR myocardial injury. For this purpose, epicatechin (1 mg/kg/day) pre‐treatment (Tx) was administered via oral gavage to 250 g male rats for either 2 or 10 days. Control groups received water. IR was induced via a 45 min coronary occlusion. Reperfusion was allowed to occur for 48 h while Tx continued. We measured infarct (MI) size (%), hemodynamics, myeloperoxidase (MPO) activiy, tissue oxidative stress, matrix metalloproteinase‐9 (MMP‐9) and NFκB activities. With 2 days of Tx, no reductions in MI size occurred. After 10 days, a significant (p <0.01) ∼50% reduction in MI size was observed. Effects were independent of changes in blood pressure since epicatechin animas demonstrated sustained hemodynamics. MPO activity and MMP‐9 activity was significantly reduced (∼50%) in the infarct region compared to non‐infarct regions. Tissue oxidative stress and NFκB activity demonstrated trends towards reductions (∼30%) in the infarct region. Results indicate that cocoa flavanols confer significant cardioprotection via anti‐inflammatory actions in the setting of IR injury and that these effects are independent of changes in hemodynamics. Supported by HL‐43617 and 67922.