Antidiabetic activity of nanopowdered chitosan in db/db mice

Present study was carried out to examine effects of nanopowdered chitosan on antidiabetic activity in db/db mice. Twenty-eight 8-week-old mice were divided into 4 groups: (1) control, nondiabetic control mice; (2) group 1, diabetic control mice with not treated chitosans; (3) group 2, diabetic mice given 2% powdered chitosan; and (4) group 3, diabetic mice given 2% nanopowdered chitosan. The serum glucose in group 3 reduced by 56%, as compared to group 2 (28%). The total serum cholesterol in group 3 decreased by 31.6%, while group 2 reduced by 18.2%. Triglyceride was decreased by 33.6% in group 3 and by 22.5% in group 2. The insulin of group 2 and 3 were significantly increased by 51.7 and 92.9%, respectively. Only group 3 was recovered from the β-cell destruction. Based on the result of the study, it is suggested that nanopowdered chitosan has higher antidiabetic activities than powdered.     

甜菜碱对db/db小鼠糖尿病肾病损伤的作用

为探究甜菜碱对db/db小鼠糖尿病肾病损伤的保护作用,将7月龄db/db小鼠随机分为模型组(生理盐水),阳性对照组(脂必妥),甜菜碱低剂量组(200 mg/kg)、中剂量组(400 mg/kg)、高剂量组(800 mg/kg)。所有小鼠均饲以高脂饲料,以诱发糖尿病肾病(DN)模型。以甜菜碱连续灌胃6周后,进行肾组织病理学观察,并检测小鼠体重,血清中血尿素氮(BUN)、血糖(GLU),总胆固醇(TC),甘油三酯(TG)、低密度脂蛋白(LDL)、转化生长因子-β1(TGF-β1)与肿瘤坏死因子-α(TNF-α)的水平。结果显示,甜菜碱处理组与模型组相比,肾小球基底膜无明显增厚,细胞外基质、糖原物质沉积及纤维含量减少,蛋白管型和炎性细胞浸润基本消失,肾小管结构逐渐恢复正常,体重和BUN、GLU、TC、TG、LDL、TNF-α、TGF-β1水平均显著降低(P0.05),最高分别降低11.5 g、3.0 mM、5.3 mM、3.1 mM、0.42 mM、0.64 mM、21 ng/L、30 ng/L。表明甜菜碱对db/db小鼠具有降糖、降脂、改善肾功能的生理作用,能延缓或抑制糖尿病肾病微血管炎症过程。     

橄榄苦苷改善db/db小鼠糖尿病的肝脏转录组学及生物信息学分析

通过转录组学及其生物信息学分析,研究了橄榄苦苷缓解db/db小鼠糖尿病的肝脏差异表达基因及相关信号通路。结果发现与db/db对照组相比,橄榄苦苷处理组的539 个基因发生显著变化,其中450 个基因显著上调,89 个基因显著下调。将上调和下调的差异表达基因在基因本体论数据库中注释,这些差异表达基因主要在细胞过程、细胞部分和结合中分布。京都基因与基因组百科全书通路富集分析结果显示上调的差异表达基因主要富集在磷酸肌醇3-激酶-蛋白激酶B信号通路途径,该通路共涉及27 个差异表达基因;下调的差异表达基因主要富集在花生四烯酸代谢和真核生物中核糖体的生物发生信号通路途径,分别涉及4 个差异表达基因。本研究为进一步阐明橄榄苦苷缓解2型糖尿病的分子机制奠定了基础。     

沙棘蛋白的特性及其对db/db糖尿病小鼠的降血糖作用

本文研究了沙棘蛋白对2型糖尿病模型db/db小鼠的降血糖作用。以m/m小鼠为正常对照组,db/db糖尿病模型小鼠为研究对象,每日灌胃300 mg/kg二甲双胍和不同剂量的沙棘蛋白,分别为沙棘蛋白高剂量组(SSPH,200 mg/kg)、沙棘蛋白中剂量组(SSPM,100 mg/kg)、沙棘蛋白低剂量组(SSPL,50 mg/kg),连续灌胃8周。测量初始血糖和体重以及灌胃第1周、第4周、第8周小鼠体重和血糖,并于第8周末对小鼠进行口服糖耐量测试(OGTTs)。db/db小鼠在实验开始时就表现出明显肥胖,行动迟缓,贪食贪饮,高血糖等症状,实验进行4周后,db/db小鼠未治疗组(DC)较沙棘蛋白治疗组体重增长缓慢、小鼠眼神呆滞、毛发稀疏、垫料潮湿。治疗8周后与DC组血糖峰值(28.06 mmol/L)相比SSPL组血糖值为19.89 mmol/L,降血糖效果显著(P<0.05),SSPH体重增加明显,增长率为9.19%,各组小鼠精神状态良好。实验表明沙棘蛋白可以明显降低db/db小鼠的血糖,减轻糖尿病对小鼠的损伤。     

沙棘籽蛋白肽对db/db小鼠降血糖活性及肾脏保护作用

本文研究了沙棘籽蛋白肽对2型糖尿病小鼠的降血糖活性及肾脏的保护作用。以m/m小鼠为正常对照组(NC),db/db糖尿病模型小鼠为研究对象,阳性对照组(PC)灌胃盐酸二甲双胍300 mg/kg/d,沙棘籽蛋白肽(SSPE)干预组分为低、中、高剂量组(50、150、250 mg/kg/d),持续灌胃8周。测定其体重、血糖、脏器指数、肾脏相关指标以及肾脏组织病理切片来评估SSPE的降血糖活性以及对肾脏的保护作用。db/db为基因缺陷型糖尿病小鼠,治疗初期表现出高血糖、肥胖、多饮多食多尿等症状,实验进行4周后,空白对照组(BC)小鼠较SSPE组出现较为严重的"三多一少"症状。干预8周后,SSPE组的血糖值(低中高分别为:19.53、19.94、20.00 mmol/L)显著低于BC组血糖峰值(29.56 mmol/L)。SSPE组的脏器指数、肾脏相关的各项血清指标均处显著低于BC组(P<0.05),肾脏组织病理切片也显示糖尿病肾病的典型症状得到改善。实验表明SSPE可显著降低糖尿病小鼠的血糖水平,对肾功能有一定的保护作用。     

金枪鱼胰脏酶解多肽对db/db糖尿病小鼠肾脏的保护作用

目的:研究金枪鱼胰脏酶解多肽对db/db糖尿病小鼠体质量、血清胰岛素、糖化血红蛋白、血脂的影响,为进一步开发金枪鱼胰脏、研制新型保健型食品提供理论依据。方法:雄性Db/m小鼠为空白对照组,雄性db/db小鼠30只,分为模型对照组、阳性药组(甲基巴多索隆9.75 mg/(kg·d))、实验组,实验组灌胃金枪鱼胰脏酶解多肽(50 mg/(kg·d))。10周后测定各组小鼠体质量、血清胰岛素、糖化血红蛋白、血脂水平等指标。利用基因芯片技术,比较不同组间肾脏基因的表达水平。结果:与模型对照组相比,实验组能显著降低糖尿病小鼠的体质量、血清胰岛素、糖基化血红蛋白水平;降低总胆固醇、甘油三酯、低密度脂蛋白胆固醇水平,升高高密度脂蛋白胆固醇水平。并且,与模型对照组的差异表达比较,实验组基因表达水平有显著改变,获得差异基因678个,其中161个上调,517个下调。结论:金枪鱼胰脏酶解多肽可以改善db/db糖尿病小鼠的体质量、血清胰岛素、糖化血红蛋白、血脂水平,其作用效应可能与其下调醛固酮合成相关基因CYP11B1的表达水平有关。     

Effects of buckwheat sprouts on plasma and hepatic parameters in type 2 diabetic db/db mice

We examined the effects of buckwheat sprouts (BS) (Fagopyrum esculentum Moench) on lipid and carbohydrate metabolism and on in vivo oxidative stress in type 2 diabetic mice. Mice (C57BL/KsJ-lepr(db)/lepr(db), db/db) were fed a diet containing 0%, 5%, or 10% BS based on AIN-93G for 21 d. Plasma parameters, such as total cholesterol, arteriosclerotic index, thiobarbituric acid reactive substances (TBARS), and the HbA1c concentration of whole blood in the diabetic BS-fed groups were lower than those in the diabetic control (AIN-93G) group. Concentrations of hepatic parameters, such as lipids, total cholesterol, triglyceride, and TBARS levels in BS-fed groups, were lower than those in the diabetic control group. Although gene expressions of the hepatic lipid regulation enzymes such as 3-hydroxy-3-methylglutaryl-CoA reductase (HMG-CoAR) and cholesterol 7α-hydroxylase (CYP7A1) in diabetic BS-fed groups were higher than in the diabetic control group, the elevation of mRNA level of CYP7A1 was greater than that of HMG-CoAR. In addition, concentration of bile acids in feces was higher in the diabetic BS-fed groups than in the diabetic control group. These results suggest that BS have various in vivo activities in relation to antidiabetic effects in type 2 diabetic mice, especially for improvement in lipid metabolism. It was deduced that excretion of bile acids in feces by feeding the BS diet would contribute to the suppression of the cholesterol concentration in the plasma and liver tissues of mice.     

Anti-diabetic effect of the soybean extract fermented by Bacillus subtilis MORI in db/db mice

This study investigated the effects of soy bean extract fermented by Bacillus subtilis MORI (BTD-1) on blood glucose, hemoglobin A1c (HbA1c), plasma insulin, and pancreatic β islets in db/db mice. The BTD-1 (500 mg/kg) group showed significantly lower fasting blood glucose level (p<0.01) and postprandial 2 h blood glucose level (p<0.01) compared with the db control group. The BTD-1 (500 mg/kg) group showed significantly lower HbA1c level compared with the db control group (p<0.01). After 8 weeks of BTD-1 administration, the pancreatic islet architecture was preserved and the immunofluorescent intensities of insulin in BTD-1 (500mg/kg) group apparently increased compared to in the db control group. Plasma insulin levels were found to be significantly higher in the BTD-1 (500 mg/kg) group than in the db control group (p<0.05). In summary, our results suggest that BTD-1 has an anti-diabetes effect in a non-insulin dependent diabetes mellitus mouse model.     

Mung bean coat ameliorates hyperglycemia and the antioxidant status in type 2 diabetic db/db mice

The hypoglycemic and antioxidant effect of mung bean coat (MBC) in an animal model of type 2 diabetes was investigated. A 95% ethanol extract of MBC inhibited yeast α-glucosidase activity by 48.6% in vitro, which was 1.4× stronger than inhibition by acarbose at a concentration of 0.5 mg/mL. Five week old db/db mice were fed an AIN-93G diet or a diet containing the MBC extract at 1% for 7 weeks. Blood glycated hemoglobin and serum glucose levels, as well as the homeostasis model assessment for insulin resistance in MBC group mice, were significantly (p<0.01) lower than in control group mice. Consumption of the MBC extract reduced thiobarbituric acid reactive substance levels and elevated activities of superoxide dismutase, catalase, and glutathione peroxidase in the liver, compared with the control group. MBC can be effective for improving hyperglycemia and the antioxidant status in type 2 diabetes mellitus.     

人参低聚肽对老年db/db小鼠血糖及免疫调节的作用

目的:评估人参低聚肽改善老年db/db小鼠血糖以及炎症因子和氧化应激状态的效果。方法:db/db小鼠随机分为老年模型对照组、阳性对照组、人参低聚肽干预组,同时以db/m小鼠作为正常对照组,并且取喂养至35周龄的青年db/db小鼠作为青年模型对照组。干预期间和干预结束后对各组小鼠进行空腹血糖、糖耐量水平、炎症反应程度和氧化应激状态的测定。结果:人参低聚肽可显著降低70周db/db小鼠空腹血糖(P<0.05),人参低聚肽干预组的小鼠血糖峰值和血糖曲线下面积(AUC)低于老年模型对照组、阳性对照组、青年模型对照组。人参低聚肽干预组小鼠IL-6(412.61±12.18 pg/L)低于正常对照组(476.50±30.00 pg/L),并且显著低于老年模型对照组(P<0.05),正常对照组、人参低聚肽干预组、阳性对照组和青年模型对照组的SOD和GSH-Px含量均显著高于老年模型对照组(P<0.05)。结论:人参低聚肽可以在一定程度上改善老年db/db小鼠血糖和糖耐量情况,其可能的作用机制是降低小鼠炎症因子和改善氧化应激状态,调节其免疫。     

Ameliorating effects of a nopal (Opuntia ficus-indica) complex on blood glucose in db/db mice

This study investigated the effects of a nopal (Opuntia ficus-indica) complex (OF) on blood glucose metabolism in db/db mice for 4 weeks. Food and water intake significantly decreased in OF-treated mice compared to controls (p<0.05). In addition, blood glucose and plasma insulin levels were significantly reduced in the OF-treated group compared to the controls (p<0.05). Histopathological analysis showed that the morphology of pancreatic islets was improved in the OF-treated db/db mice. Immunohistochemistry of the pancreatic islets showed that insulin production and the number of β-cells apparently increased.     

香椿叶提取物对II型糖尿病db/db小鼠的降血糖作用研究

目的 研究香椿叶提取物对II型糖尿病db/db模型小鼠的降血糖活性,为香椿老叶的综合利用提供科学依据。方法 以自发性II型糖尿病db/db小鼠为模型,以二甲双胍为阳性药物,评价香椿叶提取物的降血糖和抗氧化功能。db/db小鼠被随机分为：模型组、阳性药组(二甲双胍,50 mg/kg BW)、高剂量香椿叶组(1.0 g /kg BW)、低剂量香椿叶组(0.5 g/kg BW)和安慰剂,另设正常组。给药8周后,检测各组小鼠血浆血糖、HbA1c、TC、TG、MDA、SOD、TNF-α和IL-1β的水平,并通过组织病理学观察胰腺组织的病理学变化。结果 香椿叶提取物能够显著降低II型糖尿病db/db模型小鼠血糖及炎症因子水平,并能够改善糖尿病小鼠胰岛纤维化。WB分析表明,香椿叶提取物可通过增加胰岛素受体底物-1的磷酸化水平改善胰岛素抵抗发挥降血糖作用。结论 研究结果表明,香椿叶提取物可能通过调控ISR-1磷酸化水平降低胰岛素抵抗、保护胰岛细胞、延缓胰岛细胞纤维化,发挥降血糖作用。     

Effect of king oyster mushroom (Pleurotus eryngii) on insulin resistance and dyslipidemia in db/db mice

The present study examined the effect of the king oyster mushroom (Pleurotus eryngii) on insulin resistance and dyslipidemia in db/db mice. Four-week-old db/db mice were fed an AIN-93G diet or a diet containing 5% king oyster mushroom for 7 weeks. The blood glycated hemoglobin and serum glucose levels in the mushroom group were significantly lower than the control group (p<0.05). Dietary king oyster mushroom significantly reduced the homeostasis model assessment for insulin resistance (HOMA-IR), total cholesterol, and triglyceride, and increased high density lipoprotein (HDL)-cholesterol. These results indicate that king oyster mushroom improves insulin sensitivity and exerts anti-hyperglycemic and anti-hyperlipidemic effects in db/db mice.     

Effect of Dongchunghacho (Cordyceps militaris) on hyperglycemia and dyslipidemia in type 2 diabetic db/db mice

Controlling hyperglycemia and dyslipidemia is associated with reduced risks for diabetic complications. The present study examined the effect of dongchunghacho (Cordyceps militaris; CM) on hyperglycemia and dyslipidemia in an animal model of type 2 diabetes. Fiveweek-old db/db mice were fed an AIN-93G diet or a diet containing 1% CM water extract, whereas db/+ mice were offered the AIN-93G diet for 6 weeks. Consumption of CM significantly decreased blood glycated hemoglobin and serum glucose levels, as well as homeostasis model assessment for insulin resistance (HOMA-IR), in db/db mice. CM significantly lowered serum triglyceride and total cholesterol levels, and increased HDL-cholesterol level. CM water extract inhibited rat intestinal α-glucosidase, with an IC₅₀ of 182 μg/mL in vitro. These results indicate that CM exerted hypoglycemic and hypolipidemic effects in db/db mice.     

D-Psicose,a Sweet Monosaccharide,Ameliorate Hyperglycemia,and Dyslipidemia in C57BL/6J db/db Mice

ABSTRACT: D-psicose has been implicated in glycemic control in recent animal and human studies. In this study, the effects of D-psicose on glycemic responses, insulin release, and lipid profiles were compared with those of D-glucose and D-fructose in a genetic diabetes model. C57BL/6J db/db mice were orally supplemented with 200 mg/kg BW of D-psicose, D-glucose, or D-fructose, respectively, while diabetes control or wild type mice were supplemented with water instead. D-psicose sustained weight gain by about 10% compared to other groups. The initial blood glucose level maintained from 276 to 305 mg/dL during 28 d in the D-psicose group, whereas a 2-fold increase was found in other groups (P < 0.05) among diabetic mice. D-psicose significantly improved glucose tolerance and the areas under the curve (AUC) for glucose among diabetes (P < 0.05), but had no effect on serum insulin concentration. The plasma lipid profile was not changed by supplemental monosacchrides, although the ratio of LDL-cholesterol/HDL-cholesterol was ameliorated by D-psicose. The administration of D-psicose reversed hepatic concentrations of triglyceride (TG) and total cholesterol (TC) by 37.88% and 62.89%, respectively, compared to the diabetes control (P < 0.05). The current findings suggest that D-psicose shows promise as an antidiabetic and may have antidyslipidemic effects in type 2 diabetes.     

Ethylacetate extracts of the muscles of Anguilla japonica suppress glucose levels in db/db mice via activation of AMP-activated protein kinase

Hypoglycemic effects of ethylacetate extracts of Anguilla japonica (EMA) muscles in db/db mice were investigated. To understand the mechanism responsible for the hypoglycemic effects of EMA, the effects of EMA on AMP-activated protein kinase (AMPK) activation in L6 myotubes and in vivo using type II diabetic db/db mice were analyzed. In L6 myotubes, the phosphorylation degrees of AMPK and acetyl-CoA carboxylase (ACC) were markedly increased and glucose uptake was significantly (p<0.001) increased by EMA, compared with untretaed L6 myotubes. However, in L6 myotubes, these effects were abolished by compound C, an AMPK inhibitor. Moreover, EMA significantly reduced non-fasting blood glucose and serum insulin levels, and strongly induced AMPK phosphorylation in skeletal muscle tissues of db/db mice. EMA regulates glucose levels in L6 myotubes and in diabetic mice by activation of AMPK. Beneficial effects for diabetes treatment are indicated.     

Effect of curcumin supplementation on blood glucose, plasma insulin, and glucose homeostasis related enzyme activities in diabetic db/db mice

We investigated the effect of curcumin on insulin resistance and glucose homeostasis in male C57BL/KsJ-db/db mice and their age-matched lean non-diabetic db/+ mice. Both db/+ and db/db mice were fed with or without curcumin (0.02%, wt/wt) for 6 wks. Curcumin significantly lowered blood glucose and HbA 1c levels, and it suppressed body weight loss in db/db mice. Curcumin improved homeostasis model assessment of insulin resistance and glucose tolerance, and elevated the plasma insulin level in db/db mice. Hepatic glucokinase activity was significantly higher in the curcumin-supplemented db/db group than in the db/db group, whereas glucose-6-phosphatase and phosphoenolpyruvate carboxykinase activities were significantly lower. In db/db mice, curcumin significantly lowered the hepatic activities of fatty acid synthase, beta-oxidation, 3-hydroxy-3-methylglutaryl coenzyme reductase, and acyl-CoA: cholesterol acyltransferase. Curcumin significantly lowered plasma free fatty acid, cholesterol, and triglyceride concentrations and increased the hepatic glycogen and skeletal muscle lipoprotein lipase in db/db mice. Curcumin normalized erythrocyte and hepatic antioxidant enzyme activities (superoxide dismutase, catalase, gluthathione peroxidase) in db/db mice that resulted in a significant reduction in lipid peroxidation. However, curcumin showed no effect on the blood glucose, plasma insulin, and glucose regulating enzyme activities in db/+ mice. These results suggest that curcumin seemed to be a potential glucose-lowering agent and antioxidant in type 2 diabetic db/db mice, but had no affect in non-diabetic db/+ mice.     

Low-dose grape pomace and omija fruit extract is more effective than high-dose in lowering oxidative stress and fat-pad mass in db/db mice

Food Science and Biotechnology - Previous studies have shown that the mixture of extracts of grape pomace and omija (GO) improved oxidative stress and obesity in mice. This study first investigated...