桑叶提取物对糖尿病小鼠心肌保护作用的研究

目的 基于氧化应激探究桑叶提取物（MLE）对糖尿病小鼠心肌保护作用及机制。 方法 采用链脲佐菌素（STZ）及高糖脂饲料（HFD）诱导的糖尿病小鼠模型，以二甲双胍（Met，200 mg/kg）为阳性对照，分别给予100 mg/kg、200 mg/kg、400 mg/kg的桑叶提取物对糖尿病小鼠灌胃给药，干预12周后检测各组小鼠的体质量变化、血糖、糖化血清蛋白、血脂、肝肾功能、心功能、心肌结构变化及氧化应激水平。 结果 与正常组小鼠相比，糖尿病小鼠的一般情况较差，空腹血糖（FBG）、糖化血清蛋白（GSP）显著升高（P<0.01），体质量（BW）降低（P<0.01），总胆固醇（TG）、甘油三酯（TC）升高（P<0.01），心脏出现了明显的病理结构性改变，心功能显著下降（P<0.01），活性氧簇（ROS）累积增多（P<0.01），SIRT1及SOD的表达显著降低（P<0.01），氧化应激水平显著升高（P<0.01）；与模型组比较，给予400 mg/kg的桑叶提取物能够显著改善（P<0.01）糖尿病小鼠的糖脂代谢能力、心功能、心肌组织结构病变及氧化应激水平。 结论 桑叶提取物能对糖尿病小鼠的心功能具有保护作用，且该作用与抑制心肌组织的氧化应激反应有关。

Study on myocardial protective effect of mulberry leaves extracton in diabetic mice

AIM To explore the myocardial protective effect of mulberry leaf extract (MLE) on diabetic mice based on oxidative stress. METHODS Diabetic mice were induced by streptozotocin (STZ) and high glucose and lipid diet (HFD). Metformin (Met, 200 mg/kg) was used as positive control. MLE (100 mg/kg, 200 mg/kg, 400 mg/kg) was given to diabetic mice by gavage respectively. After 12 weeks of intervention, the changes of body weight, blood glucose, glycosylated serum protein, blood lipid, liver and kidney function, heart function and myocardial structure and oxidative stress were detected. RESULTS Compared with the normal group, the general condition of diabetic mice was obviously abnormal (P<0.01), the metabolism of glucose and lipid was disordered (P<0.01), the heart appeared obvious pathological structural changes, the cardiac function was significantly decreased (P<0.01), the accumulation of reactive oxygen species (ROS) was increased (P<0.01), the expression of SIRT1 and SOD was significantly decreased (P<0.01), and the level of oxidative stress was significantly increased (P<0.01); compared with the model group, 400 mg / kg mulberry leaf extract could significantly improve the glucose and lipid metabolism ability, cardiac function, pathological changes of myocardial tissue structure and the level of oxidative stress of diabetes mice (P<0.01). CONCLUSION Mulberry leaf extract protects the cardiac function of diabetic mice, and the effect is related to the inhibition of oxidative stress in myocardial tissue.