大豆异黄酮对糖尿病大鼠心肌损伤的保护作用

目的:研究大豆异黄酮对糖尿病大鼠心肌损伤的保护作用。方法:采用腹腔注射链脲佐菌素(streptozotocin,STZ)的方法制备2型糖尿病大鼠模型,取100只模型大鼠随机分为模型组,大豆异黄酮40 mg·kg~(-1)组、80 mg·kg~(-1)组、160mg·kg~(-1)组、320 mg·kg~(-1)组,每组20只;另设正常对照组。给药治疗8周后,测定各组大鼠体质量和心脏指数;检测血清中谷草转氨酶(aspartate transaminase,AST)、乳酸脱氢酶(lactate dehydrogenase,LDH)、肌酸激酶(creatine kinase,CK)、丙二醛(Malondialdehyde,MDA)含量以及总抗氧化能力(total antioxidant capacity,TAOC);测定心肌组织中超氧化物歧化酶(superoxide dismutase,SOD)和过氧化氢酶(catalase,CAT)活性;通过苏木精-伊红(Hematoxylin-Euphorbia,HE)染色观察心肌组织病理学改变,通过TUNEL染色观察心肌细胞凋亡状况并计算凋亡指数(apoptosis index,AI)。结果:与模型组比较,大豆异黄酮80 mg·kg~(-1)组、160 mg·kg~(-1)组、320 mg·kg~(-1)组大鼠血清AST、LDH、CK、MDA水平显著降低(P0.05,P0.01),心肌组织中SOD、CAT活性显著升高(P0.05,P0.01);大豆异黄酮160 mg·kg~(-1)组、320 mg·kg~(-1)组大鼠体质量显著增高、心脏指数显著降低(P0.05);血清中TAOC显著升高(P0.05);大豆异黄酮各组心肌组织病理学改变和心肌细胞凋亡程度均出现不同程度的改善,并且大豆异黄酮160 mg·kg~(-1)组、320 mg·kg~(-1)组大鼠心肌细胞AI显著降低(P0.05,P0.01)。上述各指标变化均以320 mg·kg~(-1)组最为显著。结论:大豆异黄酮能够有效改善糖尿病大鼠体质量,降低心脏指数,改善心肌组织抗氧化酶系统活性、抑制自由基损伤,抑制心肌组织病变和细胞凋亡,提示大豆异黄酮对糖尿病大鼠心肌组织具有保护作用。

The Protective Effect of Soybean Isoflavone on Heart Injury in Diabetic Rats

Objective:To investigate the protective effects of soybean isoflavone (SI) on heart injury in diabetic rats.Methods:Expect normal group,the experimental diabetes model were made by intraperitoneal injecting streptozotocin(STZ) and were randomly divided into six groups:normal group,diabetes model group,SI 40 mg · kg-1,80 mg · kg-1,160 mg · kg-1 and 320 mg · kg-1 treated groups,which was 20 experimental animals every group.Eight weeks later,the body weight and cardiac index were detected;the total antioxidant capacity(T-AOC) and the content of aspartate transaminase (AST),lactate dehydrogenase (LDH),creatine kinase (CK) and Malondialdehyde (MDA) in serum were determined;the activity of superoxide dismutase (SOD) and catalase (CAT) in cardiac tissue were also determined;and the histopathological changes of cardiac tissue was observed by HE staining and apoptosis index (AI) was calculated.Results:Compared with the diabetes model group,the content of AST,LDH,CK and MDA in serum of SI (80 mg · kg-1,160 mg· kg-1,320 mg · kg-1) treated groups were significantly decreased (P ＜ 0.05,P ＜ 0.01);and the activity of SOD and CAT in cardiac tissue was significantly decreased (P ＜ 0.05,P ＜ 0.01).The body weight and cardiac index of SI (160 mg · kg-1,320 mg · kg-1) treated groups were significantly different (P ＜0.05) and the T-AOC in serum were significantly increased compared with the diabetes model group (P ＜ 0.05).The histopathological changes and the myocardial apoptosis were significantly improved,and the AI of SI (160 mg · kg-1,320 mg · kg-1) treated groups were significantly decreased (P ＜ 0.05,P ＜ 0.01).All the above index changes were significantly in 320 mg · kg-1 group.Conclusion:SI could effectively improve the body weight,lower cardiac index,improve antioxidant ability and reduce the damage of free radical,inhibit the histopathological changes and myocardial apoptosis,suggesting that SI had cardiacprotective effect in diabetic rats.