OBJECTIVETo investigate the effects and mechanisms of hawthorn leaves flavonoids (HLF) on acute myocardial ischemia/reperfusion in anesthetized dogs.

METHODSThe acute ischemia models were prepared by ligating left anterior descending (LAD) artery for 60 min. Qualified 15 male dogs were randomly divided into 3 groups with 5 in each group: blank control (treated with normal saline 3 mL/kg) group, HLF low dosage (5 mg/kg) group and high dosage (10 mg/kg) group, with an once injection through a femoral vein 5 min before reperfusion. Epicardial electrocardiogram was adopted to measure the scope and degree of myocardial ischemia. Simultaneously, neutrophil infiltration in infarct (Inf) and remote site (RS) of myocardial tissue was measured by myeloperoxidase (MPO) activity assay. The serum interleukin-1 (IL-1) and tumor necrosis factorα (TNF-α) content were quantified by radioimmuno-assay. Furthermore, expression of G protein-coupled receptor kinase 2 (GRK2) and nuclear factor κB (NF-κB) in Inf and RS tissue were detected by Western blotting technique.

RESULTSIschemia and reperfusion increased the MPO activity and IL-1 and TNF-α content. HLF (10 and 5 mg/kg) could significantly decrease the degree and scope of myocardial ischemia; markedly inhibit the increase of MPO activity, and IL-1 and TNF-α content induced by myocardial ischemia/infarction. Furthermore, HLF increased GRK2 expression and inhibited NF-κB expression in Inf tissue.

CONCLUSIONHLF could improve the situation of acute myocardial ischemia and inhibit the inflammation in anesthetized dogs, which might be due to its increasing effect on the GRK2 and NF-κB expressions.