荭草提取物对异丙肾上腺素诱导大鼠急性心肌缺血的作用及机制

Effect and mechanism of Polygonum orientale L.extract on isoproterenol-induced acute myocardial ischemia in rats

目的探讨荭草提取物对异丙肾上腺素(ISO)诱导急性心肌缺血(MI)模型大鼠的作用及机制。方法30只清洁级Sprague-Dawley(SD)雄性大鼠随机均分为正常组、模型组、阳性对照组、荭草低剂量组及荭草高剂量组,后4组大鼠采用50 mg/kg ISO皮下注射制备大鼠急性MI模型,造模结束后,正常组和模型组大鼠蒸馏水灌胃、阳性对照组用1 g/kg复方丹参片溶液灌胃、红草低剂量组用3.2 g/kg荭草提取液灌胃、红草高剂量组用6.4 g/kg荭草提取液灌胃,2次/d,连续3 d;末次给药后0.5、2.0及6.0 h,采用针状电极监测各组大鼠心电图(ECG)ST段的偏移程度;于同时点取各组大鼠尾静脉血检测血清乳酸脱氢酶(LDH)、超氧化物歧化酶(SOD)及磷酸肌酸激酶同工酶(CK-MB)水平;末次取血结束后,取心脏制作切片、苏木精-伊红(HE)染色,观察各组大鼠心肌组织学改变。结果与正常组比较,模型组大鼠ECG ST段、血清LDH及CK-MB均明显升高,但血清SOD含量明显降低(P<0.01);与模型组比较,阳性对照组、荭草低及高剂量组大鼠ECG ST段、血清LDH及CK-MB均降低,但血清SOD含量均升高(P<0.05或P<0.01);模型组大鼠心肌细胞变性坏死、伴有出血、大量炎性细胞浸润,荭草提取物各组大鼠较模型组的心肌细胞病变明显减轻。结论荭草提取物对ISO致大鼠急性MI具有保护作用,且起效迅速,其机制可能与降低缺血大鼠心肌酶的水平、提高心肌的抗氧化能力及减轻氧化应激反应有关。

Objective To explore the effect and mechanism of Polygonum orientale L.extract on isoproterenol(ISO)-induced acute myocardial ischemia(MI)in rats.Methods Thirty clean Sprague-Dawley(SD)male rats were randomly divided into 5 groups:normal group,model group,positive control group(1 g/kg,compound salvia tablet solution),low-dose P.orientale L.group(3.2 g/kg),and high-dose P.orientale L.group(6.4 g/kg).Except for the normal group,rats in the remaining groups were subcutaneously injected with 50 mg/kg ISO to establish acute MI model.After modeling,the normal group and the model group were gavaged with the distilled water,and the other groups were gavaged with the corresponding drugs,twice a day for 3 consecutive days.At 0.5,2.0,and 6.0 h after the last administration,the needle electrode was used to monitor and record the changes of the ST segment of the electrocardiogram(ECG)of rats in each group.At the same time,1 ml of blood was collected from the caudal vein of rats in each group to detect the levels of serum lactate dehydrogenase(LDH),superoxide dismutase(SOD)and Creatine Kinase-MB(CK-MB).After the last blood collection,the section and hematoxylin-eosin(HE)staining of heart was used to observe the pathological changes of the myocardium of rats in each group.Results Compared with the normal group,the model group's ST segment of ECG,the content of serum LDH and CK-MB were significantly increased,but the content of SOD was significantly reduced(P<0.01);compared with the model group,the positive control group and the low dose and the high dose of P.orientale group’s ST segment of ECG,the content of LDH and CK-MB in serum were significantly decreased,but the content of SOD was significantly increased(P<0.05 or P<0.01).The model group’s cardiac myocytes degenerated into necrosis with hemorrhage,infiltration with a large number of inflammatory cells.Compared with the model group,the myocardial cell lesions in rats of P.orientale group were significantly relieved.Conclusion The extract of P.orientale will alleviate acute myocardial ischemia induced by ISO in rats rapidly,whose mechanism may be associated with the decrease of level of cardiac enzymes,the increase of antioxidant capacity of myocardium and the attenuation of oxidative stress reaction.