大豆异黄酮对Ⅰ型糖尿病甲基乙二醛水平及白内障并发症的影响  

Dietary soy isoflavones decrease methylglyoxal formation and prevent the diabetic cataracts in streptozotocin-induced severe diabetic rats

作　　者：卢美萍[1] SONG Xiu -yuan MENG Qing- he 

机构地区：[1]浙江大学医学院附属儿童医院,浙江杭州310003 [2]Department of Pathology and Laboratory Medicine, College of Medicine, University of Saskatchewan, 103 Hospital Drive, Saskatoon, SK, S7N 0W8, Canada)

出　　处：《中国病理生理杂志》2010年第5期971-975,共5页Chinese Journal of Pathophysiology

基　　金：浙江省自然科学基金资助项目(No.Y2090339);浙江省卫生厅资助项目(No.2008A103)

摘　　要：目的:甲基乙二醛(MG)是糖代谢产生的毒性副产物,本研究旨在探讨大豆异黄酮是否通过降低MG的产生而发挥对I型糖尿病的防治作用。方法:链脲佐菌素诱导I型糖尿病大鼠模型,给予含不同剂量大豆异黄酮的大鼠饲料喂养,按大豆异黄酮不同剂量随机分为3组:大豆异黄酮低剂量组(diabetes+LIS),大豆异黄酮高剂量组(diabetes+HIS)及模型组(diabetes)。治疗8周后处死大鼠,留取血清测定血糖、糖化血红蛋白、还原型谷胱甘肽(GSH)、胰岛素水平,HPLC法测定血清MG水平,免疫组化法检测胰岛β细胞胰岛素表达情况。结果:与模型组或diabetes+LIS组大鼠比较,HIS组大鼠血清胰岛素水平明显上升[(2.46±0.35)μg/L vs(0.55±0.04)μg/L or(0.39±0.04)μg/L,均P<0.01],血糖明显下降[(19.50±1.85)mol/L vs(28.24±3.56)mol/L or(26.94±1.82)mmol/L,均P<0.05]、糖化血红蛋白减低[(13.14±3.00)%vs(17.16±2.60)%or(17.29±4.12)%,均P<0.05],血清MG明显降低[(0.77±0.09)nmol/L vs(1.57±0.17)nmol/L or(1.91±0.28)nmol/L,均P<0.05],而血清GSH水平明显增加[(13.26±1.61)mmol/L vs(7.35±1.55)mmol/L or(5.54±1.10)mmol/L,均P<0.01],diabetes+HIS组大鼠胰岛β细胞中胰岛素表达水平也明显增加。Diabetes+HIS组大鼠白内障的发生率明显低于模型组(P<0.05)。模型组与diabetes+LIS组比较,上述指标均无显著差异。结论:大豆异黄酮对I型糖尿病具有治疗作用,并能降低I型糖尿病大鼠白内障的发生率,其机制可能与胰岛素水平增加、MG水平降低及抗氧化作用有关。AIM：Methylglyoxal （MG） is considered as a very active free radical,which is an important contributor to diabetic complications such as cataracts. The purpose of this study was to investigate the serum MG levels and protective effects of soybean isoflavones on streptozotocin induced diabetes. METHODS：Diabetes was induced in male Sprague -Dawley rats by intraperitoneal injection of 100 mg/kg streptozotocin （STZ）. Diabetic rats were then randomly di-vided into 3 groups and received a special diet supplemented with casein （diabetes）,low -isoflavone soy protein （diabetes ＋ LIS）,or high-isoflavone soy protein （diabetes ＋ HIS） for 8 weeks,respectively. RESULTS：Compared to the diabetes or diabetes ＋ LIS groups,diabetes ＋ HIS diet significantly increased serum insulin levels,and reduced serum glucose,HbA1c and methylglyoxal levels （P 0. 05 or P 0. 01）. Serum GSH levels were also increased in diabetes ＋ HIS-fed rats as compared to the diabetes or diabetes ＋ LIS rats （P 0. 01）. Significant insulin production by the β-cells of the islets was observed in diabetic rats treated with diabetes ＋ HIS protein as compared to that in diabetes group or diabetes ＋ LIS group. More importantly,the incidence of cataracts in the diabetic rats was markedly decreased in diabetes ＋ HIS group. No difference of above parameters between the rats in diabetes ＋ LIS group and diabetes group was observed.CONCLUSION：Injection of high isoflavones soy protein not only lowers the glucose levels but also reduce the incidence of cataracts in diabetic rats. The underlying mechanism of soy isoflavones are attributed to the increase in insulin secretion,the decrease in MG formation,and the antioxidant effect.

关 键 词：异黄酮类 甲基乙二醛 糖尿病 代谢 

分 类 号：R363[医药卫生—病理学]