血竭超临界提取物的降血糖作用及其机制研究

为了研究血竭超临界提取物的降血糖作用及其机制,用正常小鼠和四氧嘧啶糖尿病小鼠模型,以血糖、糖耐量为指标研究血竭超临界提取物的降糖作用。通过测定体外α-葡萄糖苷酶的活力,观察血竭超临界提取物对α-葡萄糖苷酶的抑制作用。结果发现血竭超临界提取物对正常小鼠空腹血糖无明显降低作用,能改善小鼠对蔗糖的耐受力,能降低四氧嘧啶诱导的糖尿病小鼠的空腹血糖水平,能抑制α-葡萄糖苷酶的活性。表明血竭超临界提取物对糖尿病小鼠有较好的降糖作用,对α-葡萄糖苷酶的抑制作用可能是其降血糖的机制之一。     

褐蘑菇提取物对四氧嘧啶型糖尿病小鼠降血糖活性研究

本文通过对褐蘑菇提取物的降血糖作用研究,旨在开发降血糖药物新资源.试验数据显示褐蘑菇提取物能显著降低四氧嘧啶所制备的糖尿病小鼠血糖浓度.褐蘑菇提取物高、中、低剂量组对糖尿病小鼠的降糖率分别是16.9%,20.2%和15.1%.阳性对照组的降糖率是25.1%.褐蘑菇提取物中剂量组降糖效果要优于高、低剂量组.     

蒲桃仁提取物降血糖作用的实验研究

采用四氧嘧啶糖尿病小鼠模型及肾上腺素和葡萄糖引起的高血糖小鼠模型,观察蒲桃仁乙醇提取物对实验动物的降血糖效果。蒲桃仁乙醇提取物对四氧嘧啶所致糖尿病小鼠模型、肾上腺素和葡萄糖引起的高血糖模型小鼠有明显的降血糖作用,但对正常小鼠血糖无明显影响。     

老头草半仿生提取物的降血糖作用研究

本文利用尾静脉注射四氧嘧啶90mg/kg致糖尿病小鼠模型,研究了老头草半仿生提取物(LSBE)的降血糖作用,测定了LSBE对正常和糖尿病模型小鼠的血糖(Glu)、胆固醇(Chol)、甘油三酯(TG)、血清胰岛素(Ins)和胰淀粉酶(Amy)的影响。结果显示LSBE可使正常及模型小鼠血糖明显降低,并发现治疗8d后四氧嘧啶模型小鼠Ins、TG升高,Amy降低。     

桦褐孔菌与松口蘑菌粉降血糖作用的研究

为评价桦褐孔菌和松口蘑发酵菌粉的降血糖作用,本文观察了经不同浓度桦褐孔菌和松口蘑菌粉溶液灌胃后,小鼠正常血糖、给予葡萄糖小鼠以及四氧嘧啶糖尿病小鼠血糖的变化.结果表明:桦褐孔菌、松口蘑菌粉溶液(500、1000 mg/kg)对小鼠正常血糖值、正常小鼠糖耐量没有明显影响(P>0.05);对于糖尿病小鼠血糖,桦褐孔菌低剂量组(500 mg/kg)和桦褐孔菌高剂量组(1000 mg/kg)的降糖效果较为明显(P<0.01),用药前与用药后第21 d的血糖值分别为(14.94±1.85)、(10.43±2.22)和(14.89±1.65)、(10.17±2.14) mmol/L,降糖率分别为30.23% 和31.7%.桦褐孔菌和松口蘑菌粉对于小鼠正常血糖、正常小鼠糖耐量无明显影响,对于四氧嘧啶糖尿病小鼠具有一定的降血糖效果.     

苦瓜水提醇沉物对实验性糖尿病小鼠血糖水平的实验研究

将对连续 2 8天四氧嘧啶所致糖尿病小鼠 ,分别灌胃苦瓜水提醇沉物 3.0g/kg·d、复方苦瓜水提醇沉物4 .16g/kg·d ,并用以葡萄糖氧化酶—过氧化物酶法观察了小鼠血糖水平。结果苦瓜水提醇沉物组比糖尿病对照组有明显的降糖作用 (P <0 .0 1)。     

葡萄籽原花青素提取物对糖尿病小鼠血糖的影响

为了研究葡萄籽原花青素提取物(Grape Seed Proanthocyanidin Extracts,GSPE)对糖尿病小鼠的降血糖作用及其机制,本文中采用腹腔注射四氧嘧啶(ALX)构建糖尿病动物模型.造模成功后,将糖尿病小鼠分为模型对照组、格列本脲处理组、葡萄籽原花青素提取物低、中、高三个剂量(50、100、150 mg/kg)处理组,另设正常对照组.连续灌胃给药21天,每天一次,以糖尿病小鼠的体重、血清丙二醛(MDA)含量、超氧化物歧化酶(SOD)活性胰岛素水平、空腹血糖值和糖耐量为测定指标,研究不同剂量葡萄籽原花青素提取物对糖尿病小鼠的降血糖作用及机制.结果显示原花青素高剂量组能促进体重增长,显著降低糖尿病小鼠的血糖水平和糖耐量(P＜0.01);同时降低糖尿病小鼠血清MDA水平,提高其SOD活性.通过本实验研究可以看出葡萄籽原花青素提取物具有较强的降血糖作用,降糖机制可能与其提高胰岛素水平和抗氧化能力有关.     

芒果苷对四氧嘧啶糖尿病小鼠的降糖作用研究

本研究以二甲双胍为阳性对照,观察芒果苷(12.5、25.0、50.0 mg/kg)灌胃给药4周,对四氧嘧啶性糖尿病小鼠糖脂代谢的影响。实验结果表明芒果苷(25.0、50.0 mg/kg)灌胃给药后显著降低糖尿病小鼠的血糖、血清甘油三酯和总胆固醇水平,增加小鼠肌、肝糖原含量,但对糖尿病小鼠血清胰岛素水平没有影响;组织病理学检查结果表明芒果苷对糖尿病小鼠胰岛和β细胞的数量无明显改善,提示芒果苷灌胃给药对四氧嘧啶性糖尿病小鼠有降血糖作用,其降糖作用可能与促进肌、肝糖原的合成,增加机体对葡萄糖的利用有关,对糖尿病小鼠的脂代谢紊乱也有一定改善作用。     

芜菁正丁醇提取物对四氧嘧啶型糖尿病小鼠血糖的影响

为研究芜菁正丁醇提取物对四氧嘧啶糖尿病模型小鼠的降血糖作用,对小鼠禁食不禁水24 h后,腹腔注射四氧嘧啶溶液(160 mg/kg),60 h后再禁食不禁水12 h,剪尾尖取血,测血糖值,将血糖值大于11.1 mmol/L的小鼠为实验性糖尿病模型;实验保留10只空白对照,取符合实验模型的小鼠随机分为模型、阳性(海堤参芪丸对照组225 mg/kg)和芜菁正丁醇提取物低、高剂量(20、40 g/kg)组,每天灌胃给药1次,连续14 d。实验期间分别于复制模型前、后,用药7、14 d后,剪尾取血检测血糖;末次给药结束时,小鼠摘眼球取血,分离血清测定超氧化物歧化酶(SOD)活力和丙二醛(MDA)含量。结果显示用药7、14 d后芜菁正丁醇提取物组与模型组比较,小鼠血糖值显著降低(P0.01);SOD活性显著增强(P0.01);MDA含量显著降低(P0.01)。通过研究表明高原植物芜菁对四氧嘧啶性糖尿病模型小鼠有明显的降血糖和抗氧化作用。     

虎眼万年青多糖降血糖作用的研究

目的:研究虎眼万年青多糖对四氧嘧啶诱导的糖尿病小鼠的降糖作用以及对糖尿病相关特征的影响。方法:采用腹腔注射四氧嘧啶致糖尿病小鼠模型;分成阳性药物组、模型对照组、空白对照组、虎眼万年青多糖高、中、低剂量组,连续给药14d,观察糖尿病小鼠的体重、血糖水平、总胆固醇(TG)和甘油三脂(TC)的变化。结果:经灌胃给药14d后,与空白对照组比较,模型组小鼠体质量呈下降趋势(P0.01),血糖值(P0.01)、总胆固醇TG(P0.01)、甘油三酯TC(P0.01)均明显上升;与模型组比较,虎眼万年青多糖高、中剂量组能有效降低糖尿病小鼠的血糖水平(P0.01),总胆固醇TG(P0.01),甘油三脂TC(P0.01),并且虎眼万年青多糖高剂量组可缓解糖尿病小鼠体重减轻症状(P0.01),而低剂量组作用效果不明显(P0.05)。结论:虎眼万年青多糖能够降低四氧嘧啶致糖尿病小鼠血糖水平,改善血脂代谢紊乱。     

Hypoglycemic and antihyperglycemic activity of Syzygium alternifolium (Wt.) Walp. seed extracts in normal and diabetic rats

Aqueous, ethanolic and hexane fractions of Syzygium alternifolium seeds were prepared and given different doses of these extracts individually to different batches of rats (both normal and alloxan diabetic rats) after an overnight fast. The blood glucose levels were measured at 0, 1, 3, 5 and 7 hours after the treatment. The aqueous extract of Syzygium alternifolium at a dosage of 0.75 g/kg b.w. is showing maximum blood glucose lowering effect in both normal and alloxan diabetic rats. The ethanol and hexane fractions are also showing hypoglycemic and antihyperglycemic activity, but the effect is significantly less than that of aqueous extract. The antihyperglycemic activity of Syzygium alternifolium seed was compared with the treatment of Glibenclamide.     

Antihyperglycemic activity of herb extracts on streptozotocin-induced diabetic rats

We investigated the effects of herb extracts, Rhus verniciflua, Agrimonia pilosa, Sophora japonica, and Paeonia suffruticosa, on the lowering of blood glucose levels and thiobarbituric acid reactive substances (TBARS) in streptozotocin (STZ)-induced diabetic rats. After 4 weeks, oral administration of Rhus verniciflua extract (50 mg/kg) exhibited a significant decrease in blood glucose levels in diabetic rats (P<0.05). Blood TBARS concentrations, the products of glucose oxidation in blood, were also lowered by Rhus verniciflua extract supplementation. In addition, Sophora japonica and Paeonia suffruticosa extracts significantly reduced TBARS levels versus diabetic controls. Serum concentrations of liver-function marker enzymes, GOT and GPT, were also restored by Rhus verniciflua (50 mg/kg) supplementation in diabetic rats.     

四氧嘧啶诱发糖尿病模型效果的性别差异

目的了解性别因素对四氧嘧啶诱发糖尿病动物模型的影响,为提高动物模型的复制效率提供实验依据。方法分别给雌、雄比格犬和昆明小鼠注射不同剂量的四氧嘧啶,药后3、7、14、21 d测定血糖值,同时统计实验期间动物的死亡情况。结果给予同等剂量的四氧嘧啶,雌性比雄性动物的血糖升高更快,浓度更高。雌性犬四氧嘧啶的最适造模剂量为40 mg/kg,而雄性犬在此剂量下的模型成功率只有40%,二者差异极显著（70%VS40%,P〈0.01）;雄性犬的最适使用剂量为50 mg/kg,但在此剂量下有高达30%的雌性犬因高血糖而死亡。四氧嘧啶对小鼠的影响与犬基本一致,雌雄鼠的最佳剂量分别为200 mg/kg和250 mg/kg。结论雌性动物对四氧嘧啶的敏感性较雄性动物高,雄性动物在使用四氧嘧啶复制糖尿病模型时,其剂量通常需要较雌性动物高20%左右。     

In vitro and in vivo protective effect of Ganoderma lucidum polysaccharides on alloxan-induced pancreatic islets damage

This study was undertaken to investigate the protective effect against alloxan-induced pancreatic islets damage by Ganoderma lucidum Polysaccharides (Gl-PS) isolated from the fruiting body of Ganoderma lucidum (Leyss. ex Fr.) Karst. In vitro, alloxan caused dose-dependent toxicity on the isolated pancreatic islets. Pre-treatment of islets with Gl-PS for 12 h and 24 h significantly reversed alloxan-induced islets viability loss. Gl-PS was also found to inhibit the free radicals production induced by alloxan in the isolated pancreatic islets using confocal microscopy. Gl-PS dose-dependently increased serum insulin and reduced serum glucose levels when pretreated intragastrically for 10 days in alloxan-induced diabetic mice. It was found that the pancreas homogenates had higher lipid peroxidation products in alloxan-treated mice than in the Gl-PS-treated animals. Aldehyde fuchsin staining revealed that alloxan caused nearly all the beta cells disappearing from the pancreatic islets, while Gl-PS partly protected the beta cells from necrosis. Alloxan (60 mg/kg) induced NF-kappa B activation in the pancreas at 30 min after injection, pretreatment with Gl-PS inhibited alloxan-induced activation of NF-kappa B. These results suggest that Gl-PS was useful in protecting against alloxan-induced pancreatic islets damage in vitro and in vivo; one of the mechanisms is through its scavenging ability to protect the pancreatic islets from free radicals-damage induced by alloxan.     

Effects of Se-enriched polysaccharides produced by Enterobacter cloacae Z0206 on alloxan-induced diabetic mice

In this study, the water-soluble selenium-enriched exopolysaccharides (Se-ECZ-EPS) were isolated from submerged culture broth of Enterobacter cloacae Z0206 through fermentation, ethanol precipitation and deproteinization. The protective effects of Se-ECZ-EPS on alloxan-induced diabetic mice were investigated. Diabetes was induced in ICR (Institute of Cancer Research) mice by administration of single doses of alloxan intraperitoneally (190 mg/kg body weight). Se-ECZ-EPS at a dose of 200 mg/kg body weight were administered per os (p.o.) as single dose per day to diabetes-induced mice for a period of 42 days. The decrease in body weight, serum insulin level, and the increase in blood glucose level, glycosylated serum protein (GSP), total cholesterol (TC) and triglycerides (TG) in liver were observed in diabetic mice. On the other hand, oral administration of Se-ECZ-EPS resulted in a significant reduction in fasting blood glucose levels, GSP, TC and TG contents in liver coupled with improvement of body weight and serum insulin level in comparison with diabetic control group. These results suggest that Se-ECZ-EPS possess significant protective and anti-diabetic effects in alloxan-induced diabetic mice.     

Circadian Variation in Alloxan Sensitivity of Mice as Indicated by Mortality and Blood Glucose Alteration

The objective of this study was to determine in mice if a time-dependent pancreatic β-cell susceptibility to alloxan could be correlated to daily changes in blood glucose levels and to monitor the pattern of blood glucose at various times of day as mice became diabetic. Food was removed from mice standardized to a 12-h light:dark cycle (lights on at 0600 h CST, during the month of June) at 12 h before subcutaneous injection with 0.27 mg/g of alloxan. Six groups of 30 fasted mice were injected at 4-h intervals. Blood glucose levels were measured from each group immediately prior to injection, and at 2, 4, 8, 12, 24, 48, and 216 h after treatment. Animals receiving alloxan during the early- to middark period had an increase in blood glucose after 2 h, followed by a decline to hypoglycemic levels between 4 and 8 h, and recovery to hyperglycemic levels 48 h after alloxan exposure. Three and 30% of these animals were dead at 8 and 48 h, respectively. Mice treated during the midlight span had decreased blood glucose levels 2 h after alloxan treatment followed by an increase to diabetic hyperglycemia within 48 h. Twenty-three and 70% of the animals treated at 1430 h were dead at 8 and 48 h, respectively. At 216 h, total mortality was 45.6% and 81 of the 98 surviving mice were hyperglycemic. These data suggest a greater sensitivity to alloxan during the midlight resting period of the mice. This may be the result of increased sensitivity to the insulin released from the β cells when alloxan was given during the light span.     

Dose dependent hypoglycemic effect of aqueous extract of Enicostemma littorale blume in alloxan induced diabetic rats.

Previous studies in our lab had confirmed the blood glucose lowering effect of E. littorale Blume in alloxan induced diabetic rats with no change in normoglycemic control rats. Present paper deals with dose dependent (0.5, 1.0, 1.5, 2.5, 3.5 g dry plant equivalent extract/100 g body wt., p.o.) blood glucose lowering effect of aqueous extract of E. littorale Blume in alloxan induced diabetic rats. The effective dose was found to be 1.5 g dry plant equivalent extract/100 g body wt.. The above dose caused significant decrease in glycosylated haemoglobin, liver glucose-6-phosphatase activity and significant increase in serum insulin levels of the diabetic rats. No significant changes were observed in the toxicity parameters of extract treated diabetic rats as compared to diabetic control rats. The above results suggest that E. littorale is a potent antidiabetic agent without any toxic effect at this particular dose (1.5 g dry plant equivalent extract/100 g body wt.).     

Reduced nociceptive responses in mice with alloxan induced hyperglycemia after garlic (Allium sativum Linn.) treatment.

Administration of ethanol (95%) extract (45 mg/kg body wt/day for 28 days) of garlic (A. sativum) to alloxan induced diabetic (ALX-D) mice significantly lowered the serum glucose levels, nociceptive response in tail-flick, hotplate, allodynia, formalin test and relative thickness, weight of hind paw in formalin induced Paw oedema test, over 28 days, thus, showing the reversal trend in hyperglycemia and hyperalgesia compared to ALX-D mice. The reversal of hyperglycemia and hyperalgesia was progressive and more effective as duration of extract administration increased. The results suggest therapeutic potential of ethanol extract of garlic for anti-hyperglycemic and anti-nociceptive effects in diabetes.     

番石榴多糖对糖尿病小鼠的血糖及胸腺、脾指数的影响

研究采用两种不同方法提取的番石榴多糖对四氧嘧啶致糖尿病的小鼠血糖值及胸腺、脾指数的影响。通过给小鼠腹腔注射四氧嘧啶(200 mg/kg BW)建立糖尿病小鼠模型,尾端取血,采用血糖仪分别在给小鼠灌胃多糖三天和十天后检测小鼠血糖值,第十天解剖小鼠,分别对小鼠胸腺和脾脏称重。结果表明:与糖尿病对照组比较,两组灌喂番石榴多糖的小鼠的生存质量提高,血糖值显著降低,同时胸腺指数显著增加,提示番石榴多糖具有降血糖作用,是一种潜在的糖尿病治疗药物。     

Changes in plasma glucagon, pancreatic polypeptide and insulin during development of alloxan diabetes mellitus in dog

Changes in canine plasma glucose, immunoreactive glucagon (IRG), pancreatic polypeptide (PP) and insulin (IRI) were studied during the acute development of diabetes mellitus after iv alloxan injection. 100 mg or 75 mg/kg body weight of alloxan was injected iv and blood was taken successively till one or two days later. Plasma glucose showed four phases: first immediate and moderate decrease appeared 30 min after injection, second initial hyperglycemic phase, third hypoglycemic and fourth diabetic ones. Plasma IRI had already increased to 182 +/- 60 microU/ml 10 min after injection and again began to increase after about 6 h, peaking to 134 +/- 49 microU/ml at 18 h. Plasma IRG began increasing gradually soon after alloxan injection. The initial value was 196 +/- 26 pg/ml and it increased to 534 +/- 144 pg/ml at 4 h during the initial hyperglycemic phase, then reached a higher level through the hypoglycemic and diabetic phases. The change in plasma PP was similar to that in IRG. The initial value was 256 +/- 95 pg/ml at 12 h after injection, peaking to 840 +/- 100 pg/ml in the hypoglycemic phase. Similar blunted values were obtained following 75 mg/kg alloxan injection. Thus not only plasma IRI but also plasma IRG and PP varied greatly during the acute development of alloxan diabetes and some contribution of IRG to the initial hyperglycemic phase was suggested.