补骨脂酚对链脲佐菌素诱导的大鼠糖尿病心肌病保护机制研究

Study on the protective mechanism of Bakuchiol against Streptozotocin induced diabetic cardiomyopathy in rats

目的探讨补骨脂酚对链脲佐菌素诱导的大鼠糖尿病心肌病的保护作用。方法选取45只8周龄SPF级雄性SD大鼠,体重180~220 g,采用随机数字表法将其分为对照组、糖尿病组和补骨脂酚组,每组15只。糖尿病组和补骨脂酚组进行高糖高脂饲料(HFD)饮食4周后每日腹腔注射链脲佐菌素(50 mg/kg),对照组正常饮食4周后每日腹腔注射等量生理盐水,三组均持续注射3 d。链脲佐菌素腹腔注射1周后,三组空腹12 h经口予葡萄糖(2 g/kg),在0、30、60、90、120 min时记录血糖值。糖尿病组和补骨脂酚组随机血糖≥16.7 mmol/L认为建模成功,两组继续HFD喂养8周,补骨脂酚组同时进行补骨脂酚(60 mg/kg)灌胃8周,对照组继续正常饮食8周。干预结束后行小动物超声检测心功能,取心脏组织进行苏木精-伊红染色及Masson染色,并采用TUNEL染色检测心肌凋亡指数,蛋白质印迹法检测心肌相关凋亡蛋白表达水平。结果苏木精-伊红染色及Masson染色结果显示,糖尿病组心肌排列紊乱,血管周围胶原纤维明显增多,补骨脂酚组心肌紊乱现象改善,血管周围胶原纤维减少。糖尿病组心脏左室射血分数、左室短轴缩短率、Bcl-2水平低于对照组,各时间点血糖曲线下面积、心肌细胞凋亡指数、Cleaved caspase-3/caspase-3及Bax表达水平高于对照组,差异有高度统计学意义(P<0.01)。补骨脂酚组左室射血分数、左室短轴缩短率高于糖尿病组,各时间点血糖曲线下面积、心肌细胞凋亡指数、Cleaved caspase-3/caspase-3、Bcl-2及Bax表达水平低于糖尿病组,差异有统计学意义(P<0.05)。结论补骨脂酚处理可显著减轻链脲佐菌素诱导的大鼠糖尿病心肌病,抑制凋亡信号,减少心肌细胞凋亡,改善心功能。

Objective To investigate the protective mechanism of Bakuchiol against Streptozotocin induced diabetic cardiomyopathy in rats.Methods Forty-five 8-week-old SPF male SD rats,weighing 180-220 g,were randomly divided into control group,diabetes mellitus group,and Bakuchiol group,with 15 rats in each group.After four weeks of high sugar and fat diet(HFD),the diabetes mellitus group and Bakuchiol group were injected intraperitoneal with Streptozotocin(50 mg/kg)every day.After four weeks of normal diet,the control group was injected intraperitoneally with the same amount of normal saline every day,all the three groups were injected continuously for three days.One week after intraperitoneal injection of Streptozotocin,the three groups were orally given glucose(2 g/kg)on an empty stomach for 12 h,and blood glucose values were recorded at 0,30,60,90,and 120 min.The diabetes mellitus group and Bakuchiol group were considered to be successful in modeling with random blood glucose≥16.7 mmol/L,the two groups continued to be fed HFD for eight weeks,and the Bakuchiol group was also given Bakuchiol(60 mg/kg)gavage for eight weeks.The control group continued the normal diet for eight weeks.After the intervention,the cardiac function was detected by small animals ultrasound,the heart tissue was taken for hematoxylin-eosin staining and Masson staining,the myocardial apoptosis index was detected by TUNEL staining,and the expression level of myocardial apoptosis related proteins was detected by Western blotting.Results Hematoxylin-eosin staining and Masson staining showed that the myocardial arrangement was disordered in the diabetes mellitus group and the perivascular collagen fibers increased significantly,while the myocardial disorder was improved in the Bakuchiol group and the perivascular collagen fibers decreased significantly.Left ventricular ejection fraction,left ventricular short axis shortening rate,and Bcl-2 levels in diabetes mellitus group were lower than those in control group,while the area under the blood glucose curve,myocardial apoptosis index,Cleaved caspase-3/caspase-3,and Bax expression level in model group were higher than those in control group,the differences were highly statistically significant(P<0.01).Left ventricular ejection fraction,left ventricular short axis shortening rate in Bakuchiol group were higher than those in diabetes mellitus group,while the area under the blood glucose curve,myocardial apoptosis index,Cleaved caspase-3/caspase-3,Bcl-2,and Bax expression level in Bakuchiol group were lower than those in diabetes mellitus group,the differences were statistically significant(P<0.05 or P<0.01).Conclusion Bakuchiol treatment can Significantly reduce streptozotocin induced diabetic cardiomyopathy in rats,inhibit apoptosis signal,reduce myocardial cell apoptosis,and improve cardiac function.