鹰嘴豆异黄酮提取物对糖尿病小鼠血糖和氧化-抗氧化态的效应

Effects of the isoflavone extract of Cicer arietium L.on blood glucose level and oxidation-antioxidation status in diabetic mice

目的:通过观察鹰嘴豆异黄酮对糖尿病小鼠血糖及氧化-抗氧化效应的影响,探讨其降糖机制。方法:实验于2006-08/10在中国药科大学药理教研室动物实验中心完成。①选用清洁级昆明种小白鼠50只进行造模:小鼠以高糖高脂饲料喂养4周后,按25mg/kg剂量一次尾静脉注射链脲佐菌素,注射7d后血糖升高稳定、且随机血糖达16.7mmol/L以上者为造模成功。②随机将造模成功的小鼠50只均分为5组:高血糖模型对照组、二甲双胍治疗组、鹰嘴豆异黄酮提取物低、中、高剂量组,每组10只。在各组给予高糖高脂饲料的基础上,鹰嘴豆异黄酮提取物3个剂量组分别给予25mg/kg、50mg/kg、100mg/kg的受试物,高血糖模型对照组和二甲双胍治疗组分别给予150mg/kg的蒸馏水和二甲双胍,1次/d,连续4周。③给药2周末和4周末监测空腹血糖,实验结束时于空腹12h后将小鼠处死,取血和肝脏组织,测定血清及肝组织中丙二醛含量及超氧化物歧化酶、过氧化氢酶、谷胱甘肽过氧化物酶的活性。结果:纳入50只小鼠均进入结果分析。①空腹血糖:给予鹰嘴豆异黄酮提取物2周后,高剂量组与二甲双胍治疗组小鼠血糖值显著低于高血糖模型对照组(P<0.05),且二者间差异无显著性;4周后,高、中剂量组均显著低于高血糖模型对照组(P<0.05),二甲双胍治疗组极显著低于高血糖模型对照组(P<0.01);高、中剂量组与二甲双胍治疗组间差异无显著性。②丙二醛含量:与高血糖模型对照组相比,中剂量组和二甲双胍治疗组血清和肝脏中丙二醛含量均显著降低(P<0.05),高剂量组呈极显著降低(P<0.01),且高剂量组血清中丙二醛含量显著低于二甲双胍治疗组(P<0.05)。③超氧化物歧化酶活性:中、高剂量组和二甲双胍治疗组血清和肝脏中超氧化物歧化酶活性均高于高血糖模型对照组(P<0.05)。④过氧化氢酶活性:中、高剂量组血清和高剂量组肝脏中过氧化氢酶活性高于高血糖模型对照组(P<0.05,P<0.01,P<0.05),高剂量组血清和肝脏中过氧化氢酶活性均显著高于二甲双胍治疗组(P<0.05),而二甲双胍治疗组无论血清还是肝脏中过氧化氢酶活性与高血糖模型对照组相比差异无显著性(P>0.05)。⑤谷胱甘肽过氧化物酶活性:中、高剂量组血清中谷胱甘肽过氧化物酶活性均高于高血糖模型对照组(P<0.01);各剂量组肝脏组织中谷胱甘肽过氧化物酶活性均高于高血糖模型对照组(P<0.01);二甲双胍治疗组血清和肝脏中谷胱甘肽过氧化物酶活性均显著高于高血糖模型对照组(P<0.05),但肝脏中活性仍极显著低于3个剂量组(P<0.01)。⑥给药后,模型鼠的血糖与血清超氧化物歧化酶、过氧化氢酶、谷胱甘肽过氧化物酶活性的相关系数分别为-0.9403、-0.9466和-0.9503;与肝脏超氧化物歧化酶、过氧化氢酶、谷胱甘肽过氧化物酶活性的相关系数分别为-0.9436、-0.9356和-0.9631。结论:①鹰嘴豆异黄酮提取物有显著的降血糖作用。②鹰嘴豆异黄酮提取物降血糖作用的机制可能与其提高抗氧自由基酶类的活性,保护机体组织免遭过氧化损伤有关。③鹰嘴豆异黄酮提取物在降低过氧化产物丙二醛含量、增强机体抗氧化能力方面的功能优于治疗糖尿病的常用药物二甲双胍。

AIM： To study the mechanism of reducing blood sugar of the isoflavone extract of Cicer anetium L. by evaluating its effect on blood glucose level and oxidation-antioxidation in diabetic mice. METHODS： The experiment was conducted in the animal experimental center of Department of Pharmacology, China Pharmaceutical University from August to October 2006. （1）Totally 50 Kunming mice of clean grade were selected. After 4 weeks feeding with high sugar and high fat diet, the mice ware injected with 25 mg/kg streptozotocin at tail vein. If the random blood glucose reached to 16.7 mmol/L 7 days after injection, the modeling was successful. （2）Then 50 diabetic mice ware randomly divided into 5 groups with 10 mice in each group： hyperglycemia model group, positive drug group and high, middle and low doses extract groups. Besides the high sugar and high fat diet, the mice in the low, middle and high doses extract groups were given 25 mg/kg, 50 mg/kg and 100 mg/kg isoflavone extract of Cicer arietium L, and those in the hyperglycemia model group and the positive drug group were given 150 mg/kg distilled water and metformine once a day for 4 weeks, respectively. All those treatment lasted for 4 successive weeks. （3）The fasting blood glucose was detected at the end of the 2^nd and 4^th weeks. The mice ware killed after fasting for 12 hours at the end of the 4^th week, and the blood and liver samples were drawn to detect the malonaldehyde （MDA） content and the activity of superoxide dismutase （SOD）, catalase （CAT） and glutathion peroxidase （GSH-Px） in liver and serum. RESULTS： Totally 50 mice entered the result analysis. （1）Fasting blood glucose： After two-week treatment of isoflavone extract of Cicer anetium L., the fasting blood glucose level in the high-dosage extract group and positive control group was markedly lower than that in the hyperglycemia model group （P 〈 0.05）, but no significant differerice was found; 4 weeks later, the blood glucose level in the middle and high-dosage extract groups was markedly lower than the hyperglycemia model group （P 〈 0.05）, and the positive drug group was very markedly lower than that in the hyperglycemia model group （P 〈 0.01）, but no significant difference was found among the middle-dosage, high-dosage extract groups and the positive control group. （2）MDA content： Compared with the hyperglycemia model group, MDA content in the serum and liver of the middle-dosage extract group and positive control group was significantly decreased （P 〈 0.05）, and that in the high dose extract group was very significantly decreased （P 〈 0.01 ）. Furthermore, the serum MDA content in the high dose extract group was markedly lower than that in the positive control group （P 〈 0.05）. （3）SOD activity： Both in serum and liver, the SOD activity of the middle-dosage, high-dosage extract groups and the positive control group was markedly higher than that in the hyperglycemia model group （P 〈 0.05）. （4）CAT activity： The CAT activity in serum of the middle-dosage and high-dosage groups and in liver of the high-dosage group was markedly higher than that in the hyperglycemia model group （P 〈 0.05, P 〈 0.05, P 〈 0.01）. Furthermore, the CAT activity in serum and liver in the high-dosage extract group was significantly higher than that in the hyperglycemia model group （P 〈 0.05）. However, no significant difference was found in the activity of CAT in serum and liver between the hyperglycemia model group and the positive control group （P 〉 0.05）. （5）GSH-Px activity： In serum, the activity of GSH-Px in middle-dosage and high-dosage extract groups was very markedly higher than that in hyperglycemia model group （P〈 0.01）; in liver, the activity of GSH-Px in three dose extract groups was very markedly higher than that in hyperglycemia model group （P 〈 0.01 ）; Both in serum and liver, the activity of GSH-Px in the positive control group was markedly higher than that in hyperglycemia model group （P 〈 0.05）, but that in liver was still markedly lower than that in the three dose extract groups （P 〈 0.01）. （6）After administration, the coefficient correlations of blood glucose in model rats with the activity of SOD, CAT and GSH-Px in serum were -0.940 3, -0.946 6 and -0.950 3, and with that in liver were -0.943 6, -0.935 6 and -0.963 1. CONCLUSION： （1）The isoflavone extract of Cicer anetium L. could remarkably decrease the blood glucose level of diabetic mice. （2）The mechanism of the isoflavone extract in reducing the blood sugar may be related to its effects on enhancing the activity of antioxidase and protecting the tissues from peroxidation damage. （3） The functions of the isoflavone extract in decreasing the MDA content and enhancing the anti-oxidation ability are superior to mefformine, which is routinely used to treat diabetes.