9,10-二羟基硬脂酸对糖尿病小鼠糖代谢的影响

目的研究9,10-二羟基硬脂酸(DHSA)对KKAy糖尿病小鼠糖耐量、胰岛素敏感性的影响。方法将48只雄性KKAy小鼠随机分为4组,每组12只,分别给予含4%DHSA高脂饲料、2%DHSA高脂饲料、4%橄榄油高脂饲料和4%玉米油高脂饲料。饲养5周时进行糖耐量实验、第6周进行胰岛素敏感性实验。体外检测DHSA对CV-1的PPAR-α和PPAR-γ的激活作用。结果在葡萄糖耐量试验中,4%DHSA组KKAy小鼠葡萄糖负荷后0.5h、1h血糖及血糖曲线下面积明显低于其它各组;4%DHSA组在注射胰岛素0.5h、1h后的血糖较低,反映对胰岛素的敏感性高于其它各组(P0.05);4%DHSA组体重明显低于4%玉米油高脂饲料组(P0.05)。DHSA在低浓度(5～20μmol/L)时没有激活CV-1细胞PPAR-γ的作用,而在50～100μmol/L浓度时具有激活PPAR-γ活性的作用,且具有一定的剂量-效应关系,但其活性远低于罗格列酮(ROSI)。DHSA没有激活CV-1细胞PPAR-α的作用。结论 DHSA改善KKAy糖尿病小鼠糖耐量和增加胰岛素敏感性,可能与提高PPAR-γ活性有关。     

乳清蛋白水解法及其多肽对KKAy小鼠血糖的影响

目的研究乳清蛋白的水解方法,并观察其水解多肽对KKAy糖尿病小鼠的降血糖作用。方法采用碱性蛋白酶水解乳清蛋白,透析后检测其水解度、含氮量、氨基酸含量、多肽图谱、质谱分析,并进行动物实验,检测其对KKAy小鼠糖耐量、空腹血糖和随机血糖以及血清胰岛素水平的影响。结果乳清蛋白水解多肽水解度为14.8%,含氮量68.2%,多肽分子量分布在900-1900,大部分集中在1800-1900。乳清蛋白水解多肽能降低灌胃后KKAy糖尿病小鼠血糖、显著升高灌胃后0.5h血清胰岛素水平。结论乳清蛋白水解多肽能有效降低KKAy小鼠空腹血糖、随机血糖和改善糖耐量。     

茶多糖降血糖、改善糖尿病症状作用的研究

目的 :　探讨茶多糖是否具有降低血糖、改善糖尿病症状的作用。方法 :　将四氧嘧啶导致的 型糖尿病小鼠随机分成 4组 ,每天分别灌胃给予蒸馏水、茶多糖 1 .0、2 .0、4.0 g/kgbw。每天记录饮水量 ,每周称量体重 1次 ,连续 4w,在实验中期 (2 w)、末期各测空腹血糖 1次。结果 :　茶多糖能明显缓解糖尿病小鼠“三多一少”症状 ,降低其空腹血糖 ,并存在剂量 -反应关系。同时 ,茶多糖对本实验小鼠血糖值、饮水量之间相互影响存在明显正相关性 ;饮水量与体重之间存在负相关性。结论 :　茶多糖具有降低糖尿病小鼠血糖 ,改善糖尿病症状的作用     

苦瓜多糖降血糖活性成分的研究

目的研究苦瓜多糖最佳降糖活性成分的降血糖功能及其机制。方法比较苦瓜水提多糖和苦瓜碱提多糖对链脲霉素(STZ)诱导的糖尿病小鼠的降糖效果,初步分析其降糖机制。结果苦瓜碱提多糖200和400mg/kgbw都可显著降低STZ糖尿病小鼠的血糖葡萄糖耐量及肝糖原的含量,果糖胺的含量同样也有所降低。分子量最大的苦瓜碱提多糖降糖活性最好。结论大分子量苦瓜多糖的降糖效果较好,其机制可能是通过减弱STZ对胰岛β细胞的损伤或改善受损β细胞的功能,从而起到调节血糖的作用。     

可溶性裙带菜膳食纤维对小鼠糖代谢的影响

目的研究可溶性裙带菜膳食纤维对四氧嘧啶糖尿病小鼠糖代谢的影响。方法两批正常小鼠分为正常对照组、可溶性裙带菜膳食纤维低剂量组(8·0g/kg)和高剂量组(16·0g/kg),连续灌胃21天,分别测定空腹血糖和糖耐量,同时进行糖异生实验;两批糖尿病小鼠分为动物模型组、可溶性裙带菜膳食纤维低剂量组(8·0g/kg)和高剂量组(16·0g/kg),另取正常小鼠作为正常对照组,连续灌胃21天,分别测定空腹血糖和糖耐量。结果膳食纤维高、低剂量组糖尿病小鼠的血糖曲线下面积分别为32·83±2·73、33·73±2·42,与动物模型组糖尿病小鼠(37·94±3·86)相比,差异具有显著性(P<0·05);膳食纤维高剂量组糖尿病小鼠的糖异生作用(5·6%)明显低于正常小鼠的糖异生作用(13·9%)(P<0·01);膳食纤维高剂量组糖尿病小鼠的血糖(8·62±3·14)mmol/L明显低于动物模型组糖尿病小鼠的血糖(18·2±3·7)mmol/L(P<0·01);膳食纤维对正常小鼠的血糖水平及糖耐量无明显影响。结论可溶性裙带菜膳食纤维对糖尿病小鼠具有一定的降血糖作用,同时增强其糖耐量。     

辣椒素对1型糖尿病大鼠糖代谢影响作用的研究

目的探讨辣椒素对1型糖尿病大鼠糖代谢的影响及作用机制。方法 (1)普通大鼠设为低、中、高剂量组和空白组(n=8),剂量组分别灌胃3、6、9 mg/(kg·bw)剂量的辣椒素28 d后,检测其餐后血糖,肠道淀粉酶和葡萄糖苷酶活性;(2)建立链脲佐菌素诱导糖尿病大鼠模型,将其分为低、中、高剂量组,空白组和模型组(n=8),剂量组分别灌胃3、6、9 mg/(kg·bw)剂量辣椒素28 d后,依次检测其餐后血糖,消化酶的活性,葡萄糖耐量,血清胰岛素,肝糖元和糖化血清蛋白等与糖代谢相关指标。结果中高剂量辣椒素可显著抑制正常大鼠肠道淀粉酶和葡萄糖苷酶的活性,降低负荷(葡萄糖、蔗糖和淀粉)的餐后血糖含量,以中剂量最佳。且高剂量辣椒素可显著降低糖尿病大鼠糖化血清蛋白。结论辣椒素的降血糖机制可能通过两种途径实现:(1)通过辣椒素对肠道相关酶活性的抑制以及降低小肠对碳水化合物吸收能力,实现对肠内葡萄糖吸收的干扰;(2)刺激胰岛素的分泌和肝糖原合成,抑制糖异生,从而达到降低血糖的目的。     

苦瓜粗多糖提取物降血糖作用的实验研究

目的　研究苦瓜粗多糖提取物(CPS)对正常及糖尿病小鼠血糖调节作用。方法　采用2 4只正常小鼠进行口服葡萄糖耐量试验,一次性经口给予动物葡萄糖3g kgbw ,实验组同时一次性给予CPS 1g kgbw ,对照组给予等量的生理盐水;应用1型和2型糖尿病模型小鼠,分别在随机进食和空腹情况下一次性经口给予CPS(1g kgbw) ,测定给药后2h、4h血糖水平,并与对照组血糖进行比较。结果　葡萄糖耐量试验中,实验组小鼠给予CPS 0 . 5h、1h后血糖水平显著低于对照组(分别低于对照组16 4 %和16 . 5 % ) ,差别具有显著性意义(P <0 .0 5和P <0 . 0 1)。2种糖尿病模型动物服用CPS后,各时点血糖水平较对照组显著下降(P <0 . 0 5 )。结论　苦瓜多糖粗提物对正常小鼠糖耐量有改善作用,能显著降低糖尿病模型动物随机及空腹血糖。     

高效液相色谱法测定保健食品中吡啶甲酸铬含量

随着近年来对铬元素的深入研究 ,认为三价铬是人体必需的微量营养元素 ,是葡萄糖耐量因子 (GTF)的重要组成成分。机体内的葡萄糖耐量因子和胰岛素是维持血糖浓度平衡系统的两种重要活性物质 ,作为葡萄糖耐量因子组成成分的三价铬 ,可通过激活胰岛素和细胞膜的二硫键活性 ,提高人体对葡萄糖的耐受量和胰岛素与其特异性受体相结合 ,刺激组织对葡萄糖的摄取 ,增加对葡萄糖的吸收。人体在铬缺乏时会使糖代谢紊乱 ,血胰岛素升高 ,胰岛素亲和力降低 ,α -细胞敏感性减弱 ,胰岛素受体数目减少 ,最终导致糖耐量异常和糖尿病发生。人体缺铬与长期食…     

DPP-4抑制剂有利于改善血糖控制

美国Defronzo报告，对单用二甲双胍控制血糖不理想的2型糖尿病患者，加用二肽基肽酶-4（DPP-4）抑制剂saxadiptin（SAXA）有助于改善血糖控制。与安慰剂相比，2．5、5、10mg剂量SAXA治疗24周后均能使糖化血红蛋白Alc（HbAlc）、空腹血糖和餐后胰高血糖素水平显著降低，并使口服葡萄糖耐量试验血糖曲线下面积（AUC）减小，同时增加了餐后胰岛素和C-肽AUC。     

纳米硒桔梗多糖复合物的降糖作用研究

目的:探究纳米硒桔梗多糖复合物的降糖作用。方法:根据硒含量和急毒实验结果确定灌胃给药剂量,采用腹腔注射四氧嘧啶建立糖尿病小鼠模型,通过监测小鼠体重、饮食饮水量、空腹血糖(FBG)值变化及测定小鼠血清中MDA含量和GSH-Px活性,衡量纳米硒桔梗多糖复合物的降糖效果。结果:纳米硒桔梗多糖复合物毒性较低,能明显改善糖尿病小鼠的FBG值,降低小鼠血清中MDA含量,提升GSH-Px活性。结论:纳米硒桔梗多糖复合物具有良好的降糖作用。     

Platyconic acid, a saponin from Platycodi radix, improves glucose homeostasis by enhancing insulin sensitivity in vitro and in vivo

Background

Previous research demonstrated that the crude saponins of Platycodi radix improve glucose metabolism by enhancing insulin sensitivity in type 2 diabetic animals; however, which individual saponins are the most potent insulin sensitizers is unknown.

Objectives

This study investigated which saponin(s) have anti-diabetic action in vitro and in vivo.

Methods

The insulin-stimulated glucose uptake and PPAR-γ agonistic actions of six saponins from Platycodi radix were investigated in 3T3-L1 adipocytes, and glucose-stimulated insulin secretion was determined in Min6 cells. Four individual saponins (20?mg/kg body weight) were orally administered to low-dose streptozotocin-injected diabetic mice fed a high-fat diet for 8?weeks to evaluate glucose tolerance by oral glucose tolerance testing (OGTT), insulin sensitivity by insulin tolerance testing, and insulin signaling in the liver and adipose tissues.

Results

Platyconic acid (PA) most effectively increased insulin-stimulated glucose uptake in 3T3-L1 adipocytes, possibly in part by working as a peroxisome proliferator-activated receptors (PPAR)-γ activator; however, none of the saponins improved glucose-stimulated insulin secretion in insulinoma cells. PA-treated diabetic mice exhibited the lowest peak serum glucose levels and highest serum insulin levels during the first part of OGTT. PA also improved insulin sensitivity: PA increased glycogen accumulation and decreased triacylglycerol storage in liver, which was associated with enhanced hepatic insulin signaling, while PA potentiated the expression of adiponectin and PPAR-γ in adipose tissue, and improved insulin signaling and increased GLUT4 translocation into the membranes.

Conclusions

PA improves glucose homeostasis in type 2 diabetic mice, partly by enhancing hepatic and adipocyte insulin sensitivity, possibly by activating PPAR-γ.     

复配式粗杂粮对胰岛素抵抗大鼠LCN-2表达影响

目的探讨全谷豆复配式粗杂粮对高脂膳食诱导胰岛素抵抗大鼠肝脏和脂肪组织中载脂蛋白2(LCN-2)影响。方法 40只雄性SD大鼠随机分为阴性对照组、高脂模型组、米面组和粗杂粮组,以相应饲料连续喂养8周,测定各组大鼠血清空腹血糖(FBG)和胰岛素(FINS)水平,并计算胰岛素抵抗指数(HOMA-IR);Western blotting检测各组大鼠肝脏和脂肪组织中LCN-2和过氧化物酶体增殖体激活受体-γ(PPAR-γ)蛋白表达。结果与阴性对照组比较,高脂模型组和米面组血清FBG和FINS水平明显升高(P<0.05)。高脂模型组和米面组HOMA-IR分别为(10.39±1.63)和(10.34±1.36),明显高于阴性对照组(6.85±1.33);与高脂模型组和米面组比较,粗杂粮组HOMA-IR(6.81±1.37)明显下降,粗杂粮组LCN-2在肝脏和脂肪组织中表达明显低于高脂模型组和米面组,PPAR-γ则相反。结论全谷豆复配式粗杂粮可以激活胰岛素抵抗大鼠PPAR-γ蛋白,进而降低脂肪因子LCN-2表达,改善胰岛素敏感性。     

Suppression of nocturnal fatty acid concentrations by bedtime carbohydrate supplement in type 2 diabetes: effects on insulin sensitivity, lipids, and glycemic control

BACKGROUND: Bedtime ingestion of slow-release carbohydrates leads to sustained nocturnal fatty acid suppression and improved glucose tolerance in type 2 diabetic patients. OBJECTIVE: This study assessed the effects of 2 different doses of bedtime carbohydrate supplement (BCS) on morning glycemic control and glycated hemoglobin (Hb A(1c)) in type 2 diabetic patients. In addition, the effects of the high-dose BCS on insulin sensitivity and postprandial glucose and triacylglycerol concentrations were assessed. DESIGN: Two BCS doses were studied separately in 7-wk randomized, placebo-controlled, double-blind studies with either a parallel (low-dose BCS; n = 24 patients) or crossover (high-dose BCS; n = 14 patients) design. The effects of the low and high doses (0.30 and 0.55 g uncooked cornstarch/kg body wt, respectively) were compared with those of a starch-free placebo. RESULTS: Compared with the starch-free placebo, the high-dose BCS ( approximately 45 g) produced enhanced nocturnal glucose (P < 0.01) and insulin (P < 0.01) concentrations as well as a 32% suppression of fatty acid concentrations (P < 0.01). Moreover, glucose tolerance (P < 0.05) and C-peptide response (P < 0.05) improved after breakfast the next morning. The low-dose BCS ( approximately 25 g) improved fasting blood glucose concentrations (P < 0.05). However, there were no improvements in insulin sensitivity, postprandial triacylglycerol concentrations, or Hb A(1c) after 7 wk. CONCLUSION: Nocturnal fatty acid suppression by BCS improved fasting and postprandial blood glucose concentrations in type 2 diabetic patients the next morning. In contrast, no improvements in insulin sensitivity, postprandial triacylglycerol concentrations, or long-term glycemic control assessed by Hb A(1c) were seen after BCS supplementation.     

复配式粗杂粮对大鼠胰岛素抵抗及PPAR-γ表达的影响

目的掌握复配式粗杂粮对高脂饮食诱导的大鼠胰岛素抵抗的影响。方法40只SD大鼠随机分为阴性对照组(n=10)和高脂造模组(n=30),分别给予基础饲料和高脂饲料,6周后再将高脂造模组分为高脂模型对照组、米面组、粗杂粮组(n=10),提供相应饲料。继续喂养9周后,测定大鼠血糖和胰岛素水平,RT-PCR法测定脂肪组织中过氧化物酶体增殖物激活受体-γ(PPAR-γ)mRNA表达。结果6周高脂饮食后,高脂造模组胰岛素抵抗指数(HOMA-IR)明显升高,造模成功。粗杂粮组大鼠的体重和HOMA-IR显著低于高脂模型对照组和米面组,粗杂粮组PPAR-γmRNA的表达与其他3组比较明显增加(P0.05)。结论复配式粗杂粮能显著降低高脂饮食引起的胰岛素抵抗大鼠的血糖、胰岛素水平,改善胰岛素敏感性,其机制可能与增加PPAR-γ的表达有关。     

PPAR-γ在COPD所致的肺动脉高压患者中的表达变化

目的探讨COPD所致肺动脉高压患者PPAR-γ表达水平与肺动脉压力、胰岛素抵抗的关系。方法63例COPD患者中合并肺动脉高压（PAH组）30例,无肺动脉高压COPD组33例,20例体检者为对照组。采用实时荧光定量RT—PCR测定外周血单个核细胞PPAR-γmRNA表达水平,放免法检测空腹胰岛素（FIN）,葡萄糖氧化酶法测定空腹血糖（FPG）。结果COPD组及PAH组PPAR-γ表达水平下降,FPG、FIN及IRI升高;PAH组肺动脉压力增高,PPAR-γ表达下降及IRI升高更加明显;PPAR-γ表达水平与肺动脉压力、FPG、FIN及IRI均呈负相关（r=-0．683,-0．476,-0．553,-0．589,P〈0．05）,肺动脉压力与IRI呈正相关（r=0．505,P〈0．05）。结论PPAR-γ表达下调可能与空腹血糖异常、胰岛素抵抗、肺动脉高压形成有关。     

Pan-PPAR agonist beneficial effects in overweight mice fed a high-fat high-sucrose diet

ObjectiveWe analyzed the effect of peroxisome proliferator-activated receptor (PPAR) agonists on adipose tissue morphology, adiponectin expression, and its relation to glucose and insulin levels in C57BL/6 mice fed a high-fat high-sucrose (HFHS) diet.MethodsMale C57BL/6 mice received one of five diets: standard chow, HFHS chow, or HFHS plus rosiglitazone (PPAR-γ agonist), fenofibrate (PPAR-α agonist), or bezafibrate (pan-PPAR agonist). Diets were administered for 11 wk and medications from week 6 to week 11. Glucose intolerance (GI) and insulin resistance were evaluated by oral glucose tolerance testing and homeostasis model assessment for insulin resistance, respectively. Adipocyte diameter was analyzed in epididymal, inguinal, and retroperitoneal fat pads and by adiponectin immunostain.ResultsMice fed the HFHS chow had hyperglycemia, GI, insulin resistance, increased fat pad weight, adipocyte hypertrophy, and decreased adiponectin immunostaining. Rosiglitazone improved GI, insulin sensitiveness, and adiponectin immunostaining, but it resulted in body weight gain, hyperphagia, and adipocyte and heart hypertrophy. Fenofibrate improved all parameters except for fasting glucose and GI. Bezafibrate was the most efficient in decreasing body weight and glucose intolerance.ConclusionActivation of PPAR-α, -δ, and -γ together is better than the activation of PPAR-α or -γ alone, because bezafibrate showed a wider range of action on metabolic, morphologic, and biometric alterations due to an HFHS diet in mice.     

Metformin-like effect of Salvia officinalis (common sage): is it useful in diabetes prevention?

Common sage (Salvia officinalis L.) is among the plants that are claimed to be beneficial to diabetic patients, and previous studies have suggested that some of its extracts have hypoglycaemic effects in normal and diabetic animals. In the present study, we aimed to verify the antidiabetic effects of an infusion (tea) of common sage, which is the most common form of this plant consumed. Replacing water with sage tea for 14 d lowered the fasting plasma glucose level in normal mice but had no effect on glucose clearance in response to an intraperitoneal glucose tolerance test. This indicated effects on gluconeogenesis at the level of the liver. Primary cultures of hepatocytes from healthy, sage-tea-drinking rats showed, after stimulation, a high glucose uptake capacity and decreased gluconeogenesis in response to glucagon. Essential oil from sage further increased hepatocyte sensitivity to insulin and inhibited gluconeogenesis. Overall, these effects resemble those of the pharmaceutical drug metformin, a known inhibitor of gluconeogenesis used in the treatment and prevention of type 2 diabetes mellitus. In primary cultures of rat hepatocytes isolated from streptozotocin (STZ)-induced diabetic rats, none of these activities was observed. The present results seem to indicate that sage tea does not possess antidiabetic effects at this level. However, its effects on fasting glucose levels in normal animals and its metformin-like effects on rat hepatocytes suggest that sage may be useful as a food supplement in the prevention of type 2 diabetes mellitus by lowering the plasma glucose of individuals at risk.     

门冬胰岛素应用于胰岛素泵对餐后血糖和血糖波动的影响

目的 探讨门冬胰岛素与可溶性人胰岛素在持续皮下胰岛素输注(CSII)中对餐后血糖和血糖波动的影响.方法 选择345例2型糖尿病患者,随机以门冬胰岛素(门冬胰岛素组173例)和可溶性人胰岛素(人胰岛素组172例)作为泵用胰岛素进行CSII强化治疗,监测1d 9次末梢血糖(三餐前后、22:00、0:00和3:00),比较两组餐后血糖和血糖波动情况.结果 门冬胰岛素组较人胰岛素组对空腹和早、晚餐后血糖控制更好,餐后血糖波动更小,达标时间较短[分别为(4.40±2.16)、(5.68±2.29)d](P<0.05),且低血糖的发生率明显较低(P<0.05).结论 在CSII强化治疗中,门冬胰岛素可更快、更有效降低血糖,尤其有利于餐后血糖控制和减少整体的血糖波动.