OBJECTIVETo investigate the role of p38MAPK pathway in the protective effect of glycyrrhiznatis against myocardial ischemia-reperfusion in rabbits.

METHODSThirty rabbits were randomly divided into control group, I/R group, and glycyrrhiznatis group. In the latter two groups, the left anterior descending branch of the coronary artery was ligated for 40 min followed by 120 min of reperfusion, and in glycyrrhiznatis group, glycyrrhiznatis was given intravenously at 2.5 mg/kg before the occlusion. Blood samples were taken to measure the plasma levels of TNF-alpha, IL-6, and IL-8 at 20 min before (T(0)) and 20 min (T(1)) and 40 min (T(2)) after the occlusion, and at 1 h (T(3)) and 2 h (T(4)) after the reperfusion. At the end of the reperfusion, the infarct size and the area at risk were defined by Evams and TTC staining. The heart was harvested and the levels of the p38 MAPK measured by Western blotting. The ultrastructures of the cardiac myocytes were observed under electron microscope.

RESULTSThe p38MAPK activity and the plasma levels of the inflammatory factors were significantly lower in gtycyrrhiznatis group than in I/R group (P<0.05). Glycgrrhiznatis significantly reduced the infarct size as compared with that in I/R group.

CONCLUSIONSlycyrrhiznatis can reduce myocardial ischemia-reperfusion injury by inhibiting p38MAPK activity and modulating the cytokine expression.