Choi M S, Jung U J, Yeo J, Kim M J, Lee M K
Department of Food Science and Nutrition, Kyungpook National University, Daegu, 702-701, Republic of Korea.
Diabetes Metab Res Rev. 2008 Jan-Feb;24(1):74-81. doi: 10.1002/dmrr.780.
Non-obese diabetic (NOD) mice are regarded as being excellent animal models of human type 1 diabetes or insulin dependent diabetes (IDDM). This study investigated the beneficial effects of genistein and daidzein on IDDM, an autoimmune disease.
Female NOD mice were divided into control, genistein (0.02%, w/w) and daidzein (0.02%, w/w) groups. Blood glucose level, plasma biomarkers, hepatic glucose and lipid regulating enzyme activities and pancreas immunohistochemistry analysis were examined after a 9-week experimental period.
Blood glucose levels of genistein and daidzein groups were 40 and 36% of control value at the end of study (9th week). The genistein and daidzein supplements increased insulin/glucagon ratio and C-peptide level with preservation of insulin staining beta-cell of pancreas in the NOD mice. In the liver, genistein and daidzein supplements resulted in lowering glucose-6-phosphatase (G6Pase) and phosphoenolpyruvate carboxykinase (PEPCK) activities, while increasing two lipogenic enzymes activities, malic enzyme and glucose-6-phosphate dehydrogenase (G6PD), compared to the control group. Significantly, genistein and daidzein supplementation lowered the activities of fatty acid beta-oxidation and carnitine palmitoyltransferase (CPT) in these mice. Genistein and daidzein also improved plasma triglyceride and free fatty acid (FFA) concentrations compared to the control group.
These results suggest that genistein and daidzein play important roles in regulation of glucose homeostasis in type 1 diabetic mice by down-regulating G6Pase, PEPCK, fatty acid beta-oxidation and CPT activities, while up-regulating malic enzyme and G6PD activities in liver with preservation of pancreatic beta-cells. The supplementation of genistein and daidzein are seemingly helpful for preventing IDDM onset.
非肥胖糖尿病（NOD）小鼠被视为人类1型糖尿病或胰岛素依赖型糖尿病（IDDM）的优良动物模型。本研究调查了染料木黄酮和大豆苷元对IDDM（一种自身免疫性疾病）的有益作用。
将雌性NOD小鼠分为对照组、染料木黄酮（0.02%，w/w）组和大豆苷元（0.02%，w/w）组。经过9周的实验期后，检测血糖水平、血浆生物标志物、肝脏葡萄糖和脂质调节酶活性以及胰腺免疫组织化学分析。
在研究结束时（第9周），染料木黄酮组和大豆苷元组的血糖水平分别为对照组值的40%和36%。补充染料木黄酮和大豆苷元可提高NOD小鼠胰岛素/胰高血糖素比值和C肽水平，并保留胰腺胰岛素染色β细胞。在肝脏中，与对照组相比，补充染料木黄酮和大豆苷元可降低葡萄糖-6-磷酸酶（G6Pase）和磷酸烯醇式丙酮酸羧激酶（PEPCK）活性，同时增加两种生脂酶活性，即苹果酸酶和葡萄糖-6-磷酸脱氢酶（G6PD）。值得注意地是，补充染料木黄酮和大豆苷元可降低这些小鼠的脂肪酸β氧化和肉碱棕榈酰转移酶（CPT）活性。与对照组相比，染料木黄酮和大豆苷元还改善了血浆甘油三酯和游离脂肪酸（FFA）浓度。
这些结果表明，染料木黄酮和大豆苷元通过下调G6Pase、PEPCK、脂肪酸β氧化和CPT活性，同时上调肝脏中苹果酸酶和G6PD活性并保留胰腺β细胞，在1型糖尿病小鼠的葡萄糖稳态调节中发挥重要作用。补充染料木黄酮和大豆苷元似乎有助于预防IDDM的发生。
