目的 探讨芒果苷(MGF)预处理对大鼠心肌缺血再灌注(MI/R)损伤的保护作用及机制。方法 SD大鼠随机分为5组,即假手术组、模型组和MGF高、中、低剂量(40、20、10 mg/kg)组,采用结扎左冠脉前降支30 min再灌注2 h的方法制备大鼠MI/R损伤模型,于术前7 d开始ig给药。采用比色法测定血清肌酸激酶(CK)和乳酸脱氢酶(LDH)活性,ELISA法测定血清肿瘤坏死因子-α(TNF-α)和白细胞介素-1β(IL-1β)水平;染色法测定心肌梗死面积(MIS);取心肌匀浆,比色法测定髓过氧化物酶(MPO)活性。结果 与模型组比较,MGF高、中剂量组MIS、血清LDH活性显著降低(P<0.05);MGF各剂量组血清CK活性、血清TNF-α和IL-1β水平、心肌MPO活性明显降低(P<0.05、0.01)。结论 MGF预处理通过抑制中性粒细胞浸润,下调TNF-α和IL-1β表达,抑制炎症反应,发挥对MI/R所致心肌损伤的保护作用。
Objective To investigate the protective effects of mangiferin (MGF) against myocardial ischemia/reperfusion (MI/R) injury in rats. Methods Rat model of MI/R injury was established by coronary artery ligation for 30 min followed by 2 h reperfusion. Rats were divided randomly into five groups: Sham group, model group, MGF 10, 20, and 40 mg/kg group. MGF was ig administered once daily for 7 d pre-operation. The CK and LDH activities in sera were detected by chromatometry and the levels of TNF-α and IL-1β in sera were examined by ELISA after reperfusion. The myocardial infarction size (MIS) was measured by NBT staining. The MPO activity, an index of neutrophil infiltration in heart homogenate, was determined by chromatometry. Results MGF (40 and 20 mg/kg) significantly reduced MIS and LDH activities comparing to that of model group (P < 0.05). The activity of CK in sera and MPO in heart homogenate, the levels of IL-1β and TNF-α in sera, in all MGF groups were significantly lower than those of model group (P < 0.05, 0.01). Conclusion The myocardial protection of MGF pretreatment in MI/R injury appears to be associated with the inhibition of neutrophil infiltration, expression of TNF-α and IL-1β and inflammatory response.