Cardioprotective effect of Aralia elata polysaccharide on myocardial ischemic reperfusion (IR) injury in rats

Based on the previous studies revealing antioxidant activities of a water-soluble polysaccharide (AEP-w1) from the root bark of Aralia elata, the present study was designed to determine if chronic administration of AEP-w1 could reduce ischemic reperfusion (IR) induced myocardial injury. Wistar rats were given three different doses of AEP-w1 (50, 100 and 200 mg/kg/day) or vehicle for 30 days, after which myocardial IR injury was induced by the occlusion of left anterior descending (LAD) coronary artery for 45 min followed by 60 min of reperfusion. Pretreatment with AEP-w1 not only enhanced the serum levels of total antioxidant capacity (T-AOC), superoxide dismutase (SOD) and glutathione (GSH), but also decreased the serum malondialdehyde (MDA) level in rats suffering IR injury. Consistent with this observation, AEP-w1 treatment also restored the myocardial antioxidant status evidenced by increased SOD, catalase (CAT) and glutathione (GSH) and decreased thiobarbituric acid reactive substances (TBARS) as compared to the IR model group. Furthermore, the elevated level of pro-inflammatory cytokines, such as TNF-α and IL-6, and decreased level of anti-inflammatory cytokine IL-10 in vehicle-treated IR rats was reversed by pretreatment with AEP-w1. In addition, AEP-w1 prevented myocardial cell from apoptosis in mice subjected to IR injury. These findings revealed that cardioprotective effect of AEP-w1 was achieved likely through improving endogenous antioxidants, regulating the inflammation response and suppressing myocardial cell apoptosis.