甘草多糖的抗氧化及降血糖作用研究

王晴; 洪叶; 柳振宇; 林长青

doi:10.13386/j.issn1002-0306.2022030175

甘草多糖的抗氧化及降血糖作用研究

Study on the Antioxidant and Hypoglycemic Effects of Glycyrrhiza Polysaccharide

摘要

摘要: 目的：研究甘草多糖的抗氧化作用及对1型糖尿病（Type 1 diabetes mellitus, T1DM）小鼠降血糖作用。方法：提取并纯化甘草多糖，苯酚硫酸法测定多糖含量，采用DPPH·、ABTS⁺·的清除率测定其抗氧化性。小鼠适应性喂养7 d后，对其进行腹腔注射STZ（30 mg/kg·BW），建立T1DM模型，实验分为正常组、模型组、甘草多糖高剂量组（400 mg/kg·BW）、甘草多糖低剂量组（200 mg/kg·BW）、阳性组（二甲双胍200 mg/kg·BW），实验期间测定小鼠基础指标和小鼠脂代谢及氧化应激相关指标的变化。结果：甘草多糖含量为690 mg/g，在1000 μg/mL质量浓度下其对DPPH·、ABTS⁺·的清除能力分别为82.84%±0.80%，85.52%±2.27%。在动物实验中，第8周时，甘草多糖高剂量组小鼠体重达到了20.84±0.87 g，与阳性组无显著性差异（P>0.05）。高剂量组中空腹血糖值（Fasting blood glucose, FBG）水平为15.9 mmol/L，与阳性组无显著性差异（P>0.05），且能显著提高葡萄糖耐量（Oral Glucose Tolerance Test, OGTT）水平（P<0.05）。甘草多糖高剂量组小鼠的总胆固醇（Total Cholesterol, TC）、甘油三酯（Triglyceride, TG）、高密度脂蛋白（High-density lipoprotein, HDL-C）、低密度脂蛋白（Low-density lipoprotein, LDL-C）分别为2.79±0.36、0.98±0.12、1.28±0.23、1.67±0.29 mmol/L，与模型组有极显著性差异（P<0.01），且能够极显著升高超氧化物歧化酶（Super Oxide Dismutase, SOD）、过氧化氢酶（Catalase, CAT）、总谷胱甘肽（Glutathione, GSH）的含量，极显著降低丙二醛（Malondialdehyde, MDA）含量(P<0.01)。结论：甘草多糖具有较好的抗氧化性，可以通过改善T1DM小鼠脂代谢水平和氧化应激水平从而起到降血糖作用。

Abstract: Objective: To investigate the antioxidant effect of Glycyrrhiza polysaccharide and its hypoglycemic effect on type 1 diabetes mellitus (T1DM) mice. Methods: Glycyrrhiza polysaccharides were extracted and purified, the polysaccharide content was determined by the phenol sulfuric acid method, and its antioxidant activity was determined by the clearance of DPPH· and ABTS⁺·. After 7 days of adaptive feeding, mice were intraperitoneally injected with STZ (30 mg/kg·BW) to establish a T1DM model. The experiment was divided into normal group, model group, Glycyrrhiza polysaccharide high-dose group (400 mg/kg·BW), Glycyrrhiza polysaccharide low-dose group (200 mg/kg·BW), and positive group (metformin 200 mg/kg·BW). The changes of basic indexes and indexes related to lipid metabolism and oxidative stress in mice were measured during the experiment. Results: The content of Glycyrrhiza polysaccharide was 690 mg/g, and its scavenging abilities of DPPH· and ABTS⁺· were 82.84%±0.80%, 85.52%±2.27% at 1000 μg/mL mass concentration, respectively. In the animal experiments, the body weight of mice in the high-dose group of Glycyrrhiza polysaccharide reached 20.84±0.87 g at the 8th week, which was not significantly different from the positive group (P>0.05). In the high-dose group, the fasting blood glucose (FBG) level was 15.9 mmol/L, which was not significantly different from the positive group (P>0.05), and it significantly improved the glucose tolerance (OGTT) level (P<0.05). The total cholesterol (TC), triglyceride (TG), high-density lipoprotein (HDL-C), and low-density lipoprotein (LDL-C) in the mice in the high-dose group of Glycyrrhiza polysaccharide were 2.79±0.36, 0.98±0.12, 1.28±0.23, 1.67±0.29 mmol/L, respectively, which were highly significantly different from those of the model group (P<0.05), and the levels of super oxide dismutase (SOD), catalase (CAT), and total glutathione (GSH) were increased significantly (P<0.01), and significantly reduced the content of malondialdehyde (MDA). Conclusion: Glycyrrhiza polysaccharide has good antioxidant properties and it can hypoglycemic by improving lipid metabolism and oxidative stress in T1DM mice.