Effects of an alpha-glucosidase inhibitor, acarbose, on blood glucose and serum lipids in streptozotocin-induced diabetic rats

Effects of either a single dose or a long-term administration of an alpha-glucosidase inhibitor, acarbose, on blood glucose, cholesterol concentrations in serum lipoprotein fractions, triglycerides and free fatty acids were examined in streptozotocin-induced diabetic rats. In experiment 1, starch loading tests were performed with or without adding acarbose. The addition of acarbose (0.75 mg per kg of body weight or over) significantly reduced the elevation of blood glucose levels. In experiment 2, the animals were divided into three groups: Group A fed on a control diet, Group B fed on a diet containing 5 mg acarbose in 100 g of diet and Group C fed on a diet containing 20 mg acarbose in 100 g of diet. The food intake in Group C was significantly reduced by 22% as compared to Group A, while the food intake in Group B showed no change. The high dose of acarbose showed a tendency to lower fasting blood glucose levels, but the difference was statistically insignificant. However, postprandial glucose levels in Group C at each period examined and in Group B at 30 days were significantly lower than the counterparts in Group A. Acarbose caused a dose-dependent decrease in serum total cholesterol levels and HDL-cholesterol: total cholesterol ratios were elevated in Group B and C. Serum triglyceride levels in Group B and C were extremely lower than those in Group A on and after 20 days. These results indicate that the addition of acarbose to the diet induces a decrease in postprandial blood glucose levels and simultaneously causes an improvement in lipid metabolism of streptozotocin-induced diabetic rats.     

Anti-hyperglycemic activity of an aqueous extract from flower buds of Cleistocalyx operculatus (Roxb.) Merr and Perry

A screening of 5 plants used for making drinks in Vietnam revealed a Cleistocalyx operculatus (Roxb.) Merr and Perry flower bud extract to have the highest inhibitory activity against the alpha-glucosidase enzyme. The anti-hyperglycemic effects of an aqueous extract from flower buds of Cleistocalyx operculatus (CO), a commonly used material for drink preparation in Vietnam, were therefore investigated in vitro and in vivo. In vitro, the CO extract inhibited the rat-intestinal maltase and sucrase activities, with IC50 values of 0.70 and 0.47 mg/ml, respectively. These values are lower than those for a guava leaf extract (GE; IC50 0.97 and 1.28 mg/ml, respectively). Postprandial blood glucose testing of normal mice and STZ-induced diabetic rats by maltose loading (2 g/kg body weight (bw)) showed that the blood glucose reduction with CO (500 mg/kg bw) was slightly less than that with acarbose (25 mg/kg bw) but was more potent than that with GE (500 mg/kg bw). In an 8-week experiment, the blood glucose level of STZ diabetic rats treated with 500 mg of CO/kg bw/day was markedly decreased in comparison with that of non-treated diabetic rats. Consequently, CO is considered to be a promising material for preventing and treating diabetes.     

南瓜多糖对糖尿病大鼠血糖和血脂的影响

目的：研究南瓜多糖对糖尿病大鼠血糖和血脂的影响。方法：Wistar大鼠腹腔注射四氧嘧啶后。将成模的糖尿病大鼠根据血糖和体重随机分为糖尿病组、消渴丸组和南瓜多糖组,同时设立正常对照组,并分别给予蒸馏水、消渴丸和南瓜多糖灌胃,每周测量体重一次,四周后测定空腹血糖、血清总胆固醇、甘油三酯、高密度脂蛋白、低密度脂蛋白和游离脂肪酸的含量。结果：糖尿病组大鼠体重下降,血糖显著升高,甘油三酯、总胆固醇、低密度脂蛋白和游离脂肪酸含量显著增加,而高密度脂蛋白含量显著降低;补充南瓜多糖和消渴丸后,体重逐渐增加,血糖显著下降,总胆固醇、甘油三酯、低密度脂蛋白和游离脂肪酸含量显著降低,高密度脂蛋白含量显著升高,并且南瓜多糖的降糖降脂效果优于消渴丸。结论：南瓜多糖能增加体重,降低糖尿病大鼠血糖、血脂,对糖尿病及其并发症有一定的作用。     

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.     

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。     

Effects of serpasil on lipids,lipoprotein lipase and lipogenic enzymes in alloxan diabetic rats

Diabetes intensifies the development of atherosclerosis. Treatment with antihypertensive drug, serpasil, arrested the progression of atherosclerosis in alloxan diabetic rats by significantly decreasing the concentration of cholesterol, phospholipids and triglycerides of serum, liver, kidney and aorta. Serpasil also decreased fasting blood sugar and urine sugar levels in these rats. Serpasil administration remarkably altered the deranged lipid metabolism in alloxan diabetic rats by nearly restoring the lipolytic and lipogenic enzyme activity to that of the normal     

Protective Effects of Moderate Intensity Static Magnetic Fields on Diabetic Mice

The purpose of this study was to investigate the effects of moderate-intensity static magnetic field (SMF) on diabetic mice. We studied the effects of SMF on blood glucose of normal mice by starch tolerance and glucose tolerance tests. Then, we evaluated the effects of SMF on blood glucose of diabetic mice by establishing alloxan-induced type 1 diabetic mice and high-fat diet + streptozotocin (STZ)-induced type 2 diabetic mice. The results showed that different magnetic field intensities and blank control did not affect the blood glucose of normal mice. After starch and glucose administration, different magnetic fields could improve the glucose tolerance of normal mice, and this was obvious in the 600 mT group. In the experiment of type 1 diabetic mice induced by alloxan, the results showed that different magnetic field intensities could improve the starch tolerance of mice, and that in the 400 mT group was obvious. In the experiment of type 2 diabetic mice induced by a high-fat diet + STZ, the 400 mT group could reduce food intake and water consumption in the later period. The 600 mT group could improve the starch tolerance of mice. The 400 and 600 mT groups could reduce fasting blood glucose. At the same time, total cholesterol and triglyceride decreased in different magnetic field intensities, and the 600 mT group could significantly increase the serum insulin content of mice. In summary, the results of this study suggest that SMF has a protective role in diabetic mice. Bioelectromagnetics. © 2020 Bioelectromagnetics Society     

5种药用植物对小鼠的降血糖作用

对菊叶三七(GnuradivaricatiumO.Hoffm.)、仙鹤草(AgrimoniapilosaLedeb.)、夏枯草(PrunellavulgarisL.)、女贞子(LigustrumlucidumAit.)和枸骨(IlexcornutaLindl.etPaxt.)的降糖作用进行了初步的研究。菊叶三七鲜样的水提物(0.2和0.4g kg)及95%乙醇提取物(0.2和0.4g kg)对正常小鼠的血糖有显著的降低作用,干样95%乙醇提取物(0.5、1.0和2.0g kg)对四氧嘧啶糖尿病小鼠的血糖有显著的降低作用,其中鲜样95%乙醇提取物(0 4g kg)的降糖作用优于优降糖,干样95%乙醇提取物(2.0g kg)的降糖作用与降糖灵(0.1g kg)相当。仙鹤草的水煎液(30和60g kg)对正常小鼠的血糖有显著的降低作用,95%乙醇提取物(30、60和120g kg)对四氧嘧啶糖尿病小鼠的血糖均有一定的降低作用。夏枯草的95%乙醇提取物(30、60和120g kg)和女贞子的95%乙醇提取物(11.25和22.50g kg)对四氧嘧啶糖尿病小鼠的血糖均有一定的降低作用。枸骨的正丁醇提取物(30和60g kg)对四氧嘧啶糖尿病小鼠和正常小鼠的血糖均没有影响。实验结果表明,菊叶三七是一种值得开发的降糖植物资源。     

Effects of prolonged (6 months) alpha-glucosidase inhibition on blood glucose control and insulin requirements in patients with insulin-dependent diabetes mellitus

To examine prolonged alpha-glucosidase inhibition on blood glucose control, Acarbose, a potent alpha-glucosidase inhibitor, was administered for six months to insulin-dependent diabetic patients. Acarbose administration significantly diminished postprandial blood glucose increases by 20-30% and reduced insulin requirements by about 40% in these patients. Symptoms related to its use almost disappeared after the first month of treatment. These results suggest that prolonged alpha-glucosidase inhibition improves glucose tolerance in patients with insulin-dependent diabetes mellitus. Thus, an agent like acarbose might be a useful adjunct to insulin in the treatment of diabetic patients.     

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。     

Alpha-glucosidase inhibitory effect of anti-diabetic metal ions and their complexes

We found alpha-glucosidase inhibitory (α-GI) effect of metal ions and their complexes which showed the high blood glucose lowering effect in diabetic model animals. The Cu(II) ion and its complexes showed strong α-GI activity greater than clinically used acarbose in in vitro studies. Furthermore, in in vivo experiments, α-GI action was newly discovered in normal ddy mice. These results suggested that one of action mechanisms of the anti-diabetic metal ions and complexes is related to the α-GI effects.     

Development of rat embryos cultured in serum prepared from rats with streptozotocin-induced diabetes

The effects of 40, 50, and 60 mg/kg streptozotocin (SZ) on the body weights and the glucose concentration and the osmolarity of the serum of adult rats were determined. Serum prepared from these SZ-dosed rats was used in embryo culture experiments to investigate effects of diabetic serum on rat embryos during organogenesis. The diabetic serum resulting from each of the tested doses of SZ was teratogenic to 9.5-day rat explants (embryos and their membranes), causing a range of dysmorphic lesions including craniofacial defects, heart defects, and abnormalities of the branchial arches and the otic capsules. Explants cultured in serum prepared from rats dosed with 60 mg/kg SZ also showed abnormal morphology of both the visceral yolk sac and the embryonic blood cells in the yolk sac capillaries. The development of explants repeatedly transferred between control and diabetic serum indicated that the severity of the dysmorphic effect was dependent on the duration of exposure to diabetic serum. The alternation of sera did not in itself appear to be damaging to the embryos. Explants cultured in control serum, control serum with its glucose concentration increased to that of the diabetic serum, or diabetic serum all took up the same amount of glucose from their culture medium; 30% of the embryos from the diabetic serum were abnormal compared to only 4% from the control serum and the control serum plus glucose.     

壳寡糖螯合铬对糖尿病小鼠降血糖作用的研究

探讨壳寡糖螯合铬(Cos-Cr)的降血糖作用。选择发育相近的健康雄性小鼠10只为正常对照组,糖尿病小鼠30只随机分为糖尿病对照组、壳寡糖组(Cos)和螯合铬组(Cos-Cr),每组各10只,实验期4 w,测定小鼠血糖值。壳寡糖螯合铬可以降低糖尿病小鼠血糖,增加体重,增加脾脏指数,明显缓解糖尿病小鼠饥饿和烦渴的症状。肝脏损伤明显减轻。同时观察肝组织病理变化。壳寡糖螯合铬对糖尿病小鼠有降糖,改善糖尿病症状的作用。     

Antidiabetic properties of polysaccharide- and polyphenolic-enriched fractions from the brown seaweed Ascophyllum nodosum

We screened seaweed species from Atlantic Canada for antidiabetic activity by testing extracts for alpha-glucosidase inhibitory effect and glucose uptake stimulatory activity. An aqueous ethanolic extract of Ascophyllum nodosum was found to be active in both assays, inhibiting rat intestinal alpha-glucosidase (IC50 = 77 microg/mL) and stimulating basal glucose uptake into 3T3-L1 adipocytes during a 20-minute incubation by about 3-fold (at 400 microg/mL extract). Bioassay-guided fractionation of the A. nodosum extract showed that alpha-glucosidase inhibition was associated with polyphenolic components in the extract. These polyphenolics, along with other constituents appeared to be responsible for the stimulatory activity on glucose uptake. However, attempts to further concentrate this activity through fractionation techniques were unsuccessful. A crude polyphenol extract (PPE), an enriched polyphenolic fraction (PPE-F1) and a polysaccharide extract (PSE) were prepared from commercial A. nodosum powder and administered to streptozotocin-diabetic mice for up to 4-weeks by daily gavage at 200 mg/kg body mass. PPE and PPE-F1 improved fasting serum glucose level in diabetic mice; however, the effect was only statistically significant at day 14. In addition, PPE-F1 was shown to blunt the rise in blood glucose after an oral sucrose tolerance test in diabetic mice. Mice treated with PPE and PPE-F1 had decreased blood total cholesterol and glycated serum protein levels compared with untreated diabetic mice, whereas PPE also normalized the reduction in liver glycogen level that occurred in diabetic animals. All 3 A. nodosum preparations improved blood antioxidant capacity.     

Early hyperglycemia following alloxan administration in vivo is not associated with altered hepatic mitochondrial function: acceptable model for type 1 diabetes?

Alloxan and oxidative stress, which have been detected in livers of laboratory animals shortly after in vivo alloxan administration, cause in vitro mitochondrial dysfunction, thus questioning alloxan diabetes as an acceptable model for type 1 diabetes, a model that cannot legitimately be used to investigate mitochondrial metabolism in a diabetic state. In the current study, the blood glucose concentration increased in the drug-treated group of Sprague-Dawley rats (compared with the placebo group) 45 or 60?min after alloxan treatment, whereas at 30?min the blood glucose concentration was unchanged. State 4, state 3, respiratory control, efficiency of oxidative phosphorylation, and mitochondrial ATP synthase activity, assayed using glutamate plus malate, pyruvate plus malate, or succinate as a substrate, were not negatively altered during the entire study. These results indicated that early increases of blood glucose concentration, after in vivo alloxan administration, did not lead to liver mitochondrial dysfunction, suggesting that alloxan diabetes can be used for the study of liver mitochondrial respiration in a diabetic state.     

Studies on gluconeogenesis and ketogenesis in isolated hepatocytes from alloxan diabetic rats.

Gluconeogenesis and ketogenesis were studied in isolated hepatocytes obtained from normal and alloxan diabetic rats. Insulin treatment maintained near-normal blood glucose levels and caused an increase in glycogen deposition. The third day after insulin withdrawal the rats displayed a diabetic syndrome marked by progressive hyperglycemia and glycogen depletion. Net glucose production in liver cells isolated from alloxan diabetic rats progressively increased with time up to 72 hr after the last in vivo insulin injection. Maximal glucose production was observed at 72 hr with 10 mM alanine, lactate, pyruvate, or fructose. Glucose production decreased at 96 hr. The same pattern was observed with the incorporation of labeled bicarbonate into glucose. Ketogenesis in liver cells and hepatic lipid content also peaked at 72 hr.     

甘露寡糖及壳聚糖对四氧嘧啶致糖尿病小鼠血糖血脂的影响

目的研究甘露寡糖和壳聚糖对四氧嘧啶致实验性糖尿病小鼠血糖、血脂的影响。方法随机选取70只健康小鼠,10只为正常对照组,其余由腹腔注射四氧嘧啶(150mg/kg),建立糖尿病模型,用快速血糖仪测血糖值,血糖值>11.1mmol/L的小鼠则为造模成功小鼠,将造模成功的小鼠随机分成5组,每组各12只。分别为模型对照组,高剂量、低剂量甘露寡糖处理组,高剂量、低剂量壳聚糖处理组。高低剂量分别以400mg/kg和200mg/kg糖溶液进行灌胃,空白组和模型组灌予等体积的生理盐水。12d后测定小鼠血清中血糖(GLU)、总胆固醇(CHO)、高密度脂蛋白胆固醇(HDL-C)和甘油三酯(TG)的浓度。结果甘露寡糖和壳聚糖使糖尿病小鼠的血糖与模型对照组相比有显著的降低,CHO和TG的浓度也显著降低,HDL-C显著升高;且高剂量的甘露寡糖和壳聚糖的降血糖、血脂效果优于低剂量。     

山茱萸总萜对糖尿病小鼠心肌病变的保护作用

目的:研究山茱萸总萜(TFC)对糖尿病小鼠心肌病变的保护作用。方法:雄性小鼠一次性腹腔注射四氧嘧啶220 mg/kg造成糖尿病模型。第15天后将血糖高于13.9 mmol/L的小鼠随机分为模型组和TFC组。药物以生理盐水混悬后灌胃(P.O,80 mg/kg),连续8周。结果:与正常组比较,模型组的心脏脏器系数升高;心肌组织中超氧化物歧化酶(SOD)活力明显下降,丙二醛(MDA)含量明显升高,肿瘤坏死因子-α(TNFα-)及白细胞介素-6(IL-6)升高;病理学显示模型组心肌细胞排列紊乱、肿胀,细胞间隙增大,可见炎症细胞和成纤维细胞浸润,TFC组明显得到改善。结论:山茱萸总萜对四氧嘧啶诱导的糖尿病小鼠心肌损伤有明显的改善作用,其机制可能与降血糖、抗氧化及炎症因子有关。     

Hypoglycaemic effect of defatted seeds and water soluble fibre from the seeds of Syzygium cumini (Linn.) skeels in alloxan diabetic rats

The effect of feeding orally along with diet of different fractions obtained from the seeds of S. cumini was tried on fasting blood glucose and glucose tolerance in normal and alloxan diabetic rats. The quantitative determination showed that S. cumini seeds contained 40% of water soluble gummy fibre and 15% of water insoluble neutral detergent fibre (NDF). This study demonstrated that feeding for 21 days of the diets containing 15% powdered unextracted (intact) seeds containing water soluble gummy fibre, 15% powdered defatted seeds from which lipid and saponins were removed only and 6% water soluble gummy fibre isolated from S. cumini seeds significantly lowered blood glucose levels and improved oral glucose tolerance whereas feeding of the diets containing 15% powdered degummed S. cumini seeds from which water soluble gummy fibre was removed but which contained neutral detergent fibre (NDF) and 2.25% water insoluble neutral detergent fibre (NDF) isolated from S. cumini seeds neither lowered blood glucose levels nor improved oral glucose tolerance in both normal and diabetic rats. These observations indicate that the hypoglycaemic effect of S. cumini seeds was due to water soluble gummy fibre and also that water insoluble neutral detergent fibre (NDF) and other constituents of the seeds had no significant hypoglycaemic effects.