帮你了解阿卡波糖

<正>阿卡波糖(拜唐苹)属于α-糖苷酶抑制剂类口服降糖药。它是一种复杂的低聚糖,结构类似寡糖,可在小肠上部细胞刷状缘处和寡糖竞争并与α-葡萄糖苷酶可逆地结合,抑制各种α-葡萄糖苷酶的活性,使淀粉分解成如麦芽糖(双糖)、麦芽三糖及糊精(低聚糖)的寡糖进而分解成葡萄糖的速度减慢,使蔗糖分解成葡萄糖和果糖的速     

说说阿卡波糖那点"屁事"

阿卡波糖,即α-葡萄糖苷酶抑制剂,代表药物为拜糖平.主要通过抑制小肠的α葡萄糖苷酶,抑制食物的多糖分解,使糖的吸收相应减缓,从而控制餐后高血糖.通俗地说,阿卡波糖是抑制碳水化合物(如米饭、面食等)的吸收,使餐后血糖平稳上升而不至于出现高峰,从而减少血糖波动,具有"消峰去谷"的作用,特别适合餐后血糖高、饮食中碳水化合物占比大的糖友.     

大豆胚轴提取物的降糖作用及其机制研究

目的: 研究大豆异黄酮(soybean isoflavones,SI)和皂甙(soyasaponins,SS)的降糖作用机制。方法: 普通饲料中添加20 g/kg富含SI和SS的大豆胚轴提取物(soybean hypocotyl extracts,SHE),饲喂Wistar正常大鼠和GK/Jcl(Goto-Kakizaki)2型糖尿病大鼠20 w,观察其血糖和葡萄糖耐量变化及对-葡萄糖苷酶和-淀粉酶的抑制活性。 结果: 长期食用SHE能显著降低2型糖尿病大鼠血糖水平,明显改善其葡萄糖耐量,同时能改善正常大鼠葡萄糖耐量。在糖尿病相关酶的抑制试验中,B类、E类和DDMP(2,3-dihydro-2,5-dihydroxy-6-methyl-4H-pyran-4-one)皂甙显示很强的α-葡萄糖苷酶抑制活性,其50%抑制浓度(IC50)值为10~40 mmol/L;异黄酮苷元也有很强的-葡萄糖苷酶抑制作用,其IC50值为20~150 mmol/L,异黄酮葡萄糖苷形式对α-葡萄糖苷酶的抑制活性则较弱。SI和SS还具有较弱的-淀粉酶抑制作用,浓度为1 g/L时,抑制率为10%~20%。结论: SHE具有降低糖尿病大鼠血糖水平和改善糖耐量的作用,其部分作用机制可能是通过SI和SS对 -葡萄糖苷酶和 -淀粉酶的抑制作用而实现的。     

魔芋多糖对小鼠瘦素和Na~+-K~+-ATP酶水平的影响

目的探讨魔芋多糖对高脂饮食小鼠血清瘦素和小肠粘膜Na+-K+-ATP酶水平的影响。方法将实验动物分为正常对照组、高脂对照组和高、中、低剂量魔芋多糖与高脂联合处理组共5个组,连续喂饲20天,用ELISA法测定血清瘦素水平,分光光度法测定小肠粘膜Na+-K+-ATP酶活性以及体重、体脂、血糖等指标。结果第10天高脂对照组的体重和餐后血糖为(31.3±2.11)g和(7.5±1.15)mmol/L,魔芋多糖高剂量组则为(28.0±2.06)g和(4.8±0.73)mmol/L。第20天高脂对照组的血清瘦素浓度和小肠粘膜Na+-K+与高脂联合处理-ATP酶活性为(1078.5±61.69)pg/ml和(16.2±1.48)μmolPi/(mg pro·h),魔芋多糖高剂量与高脂联合处理组则为(820.5±58.52)pg/ml和(11.2±1.10)μmolPi/(mgpro·h)。两组间各项指标差别均有显著性意义(P<0.05)。结论魔芋多糖能够降低高脂饮食小鼠餐后血糖、血清瘦素水平和小肠粘膜Na+-K+-ATP酶活性,抑制体重和体脂的增加。     

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。     

魔芋多糖对小鼠肠道吸收功能的抑制作用与机制

目的探讨魔芋多糖(konjac polysaccharide,KP)对小鼠肠道吸收功能的抑制作用与机制。方法将实验动物分为正常对照(N)、高脂(HF)和KP高、中、低剂量(KPH、KPM、KPL)共5个组,连续喂饲20d。紫外分光光度法测定小肠粘膜Na+-K+-ATP酶活性,血糖仪测定血糖并称量体重和粪便湿、干重等。结果HF组和KPH组的Na+-K+-ATP酶活性分别为16.2±1.48和11.2±1.10μmolPi/(mgpro·h),体重和餐后血糖分别为34.3±2.07g、7.5±1.15mmol/L和28.1±1.95g、4.8±0.73mmol/L。两组间各项指标的差别均有显著性意义(P<0.05)。结论KP降低小鼠餐后血糖和血清胆固醇水平,抑制体重增长、降低小肠粘膜Na+-K+-ATP酶活性,对肠道吸收功能有抑制作用。     

阿卡波糖, 会吃才会有效

阿卡波糖是临床治疗2型糖尿病常用的口服降糖药,属于α葡萄糖苷酶抑制剂.这类降糖药还有伏格列波糖、米格列醇等,它们在肠道能够抑制糖的吸收,其机制是通过竞争性抑制α葡萄糖苷酶(一种双糖类水解酶)的活性而减慢淀粉等多糖分解为蔗糖(一种双糖)和葡萄糖(一种单糖),从而降低餐后血糖.     

琼脂寡糖对糖尿病小鼠血糖和氧化-抗氧化态的效应

目的:探讨以琼二糖为主的琼脂寡糖对糖尿病小鼠的血糖及其氧化-抗氧化效应的影响。方法:利用α-葡萄糖苷酶活性的检测,研究琼二糖的降血糖机制。通过四氧嘧啶建立小鼠糖尿病模型,给药14d后,检测小鼠血糖及心、肺、肝、脑的MDA、GSH、GSH-Px、SOD水平。结果:在200～400mg/kg的剂量范围内,琼脂寡糖(含87.68%琼二糖)可明显降低糖尿病小鼠的血糖含量及各氧化指标,血糖值低于两种阳性对照组(P<0.01)。各组织的MDA水平明显下降(P<0.01),GSH,GSH-Px和SOD活性也得到较明显提高。结论:琼脂寡糖可能是通过抑制α-葡萄糖苷酶和抗氧化作用降低糖尿病小鼠的血糖水平,并可提高某些组织的抗氧化能力。     

染料木黄酮对缺氧性肺动脉高压及右心室肥大的预防作用

目的:研究染料木黄酮(genistein,Gen)对慢性缺氧性肺动脉高压(HPH)的预防作用,为防治HPH提供一种新的途径。方法:健康雄性Wistar大鼠,体重(210.3±28.7)g,随机分为5组:①平原对照组(C);②慢性缺氧组(H);③缺氧+Gen低剂量组(H+L):25mg/kg bw;④缺氧+Gen中剂量组(H+M):50mg/kg bw;⑤缺氧+Gen高剂量组(H+H):100mg/kg bw;C组在平原,②～⑤组每天灌胃大鼠受试物或与受试物等容积的二甲基亚砜(DMSO),置于减压舱,模拟海拔5000m高原,8h/d,持续21d,分别测定肺动脉压、右心室功能和右心室肥大指数。结果:Gen可以显著抑制慢性缺氧引起的肺动脉压升高(P<0.01)。单纯缺氧组右心室肥大指数RV/(LV+Sep)显著增加(P<0.01);与单纯缺氧组比较,Gen各组RV/(LV+Sep)从低剂量到高剂量呈逐渐降低的趋势(40.53±3.80)%,(39.07±3.69)%,(33.73±3.20)%,但仅高剂量组(100mg/kg bw)有显著性差异(P<0.01)。结论:Gen可以有效防治慢性缺氧性肺动脉高压,对慢性缺氧诱导的右心室肥大的预防作用与剂量有关,其作用机制有待进一步探讨。     

动态血糖监测在妊娠期糖尿病血糖波动检测中的应用

目的:探讨动态血糖监测系统在妊娠期糖尿病血糖检测中的应用。方法:选取2008年4月～2011年10月62例妊娠期糖尿病孕妇为研究对象,按照入院顺序随机平均分为观察组和对照组,观察组给予动态血糖监测,对照组给予常规指尖血糖监测,对比两组产妇血糖控制情况。结果:①观察组孕妇低血糖发生率为6.45%,明显低于对照组的22.58%(P<0.05)。②观察组孕妇清晨空腹、早餐后、午餐前、午餐2h后、晚餐前、晚餐2h后以及睡前的血糖值水平分别为(5.68±0.32)mmol/L,(5.34±0.63)mmol/L,(6.21±0.45)mmol/L,(8.23±0.73)mmol/L,(7.13±0.65)mmol/L,(7.82±0.35)mmol/L,(5.67±0.51)mmol/L,均低于对照组(P<0.05)。③观察组孕妇血糖水平得到有效控制的时间为(6.50±1.80)天,住院时间为(14.30±1.80)天,明显短于对照组(P<0.05)。结论:动态血糖监测可以监测妊娠期糖尿病孕妇的血糖波动情况,可使血糖控制更加及时有效,值得推广应用。     

Inhibitory effects of mulberry leaf extract on postprandial hyperglycemia in normal rats

We examined the inhibitory effects of aqueous ethanol extract from mulberry leaves (ME) on postprandial hyperglycemia in normal Wistar rats. ME dose-dependently suppressed the postprandial rise of blood glucose in rats, when ME (0.02-0.5 g/kg) was given 0.5 h before the administration of carbohydrates such as sucrose, maltose and starch. The ME dose showing 50% inhibition of the increment of blood glucose (ED50) was 0.11 g/kg for sucrose, 0.44 g/kg for maltose, and 0.38 g/kg for starch. ME and its basic fraction (MB) containing 1-deoxynojirimycin were assayed for their inhibitory effects (IC50) on disaccharidase derived from the small intestine of rats. The IC50 value of ME was 3.2 microg/mL for sucrase, 10 microg/mL for isomaltase, and 51 microg/mL for maltase. The IC50 value of MB was 0.36 microg/mL for sucrase, 1.1 microg/mL for isomaltase, and 6.2 microg/mL for maltase. The IC50 value of 1-deoxynojirimycin as the principle component in ME was 0.015 microg/mL for sucrase and 0.21 microg/mL for maltase, and this value was comparable to the IC50 of voglibose. The inhibitory activity of ME in a-amylase was weak. These results suggest that ME strongly suppresses postprandial hyperglycemia after carbohydrate loading by inhibiting the activity of disaccharidases in the small intestine of rats.     

Evaluation of α-glucosidase, α-amylase and protein glycation inhibitory activities of edible plants

Abstract

The present study was to investigate in vitro α-glucosidase, pancreatic α?amylase and protein glycation inhibitory activities of nine edible plants. The results indicated that total phenolics, flavonoids, and condensed tannins of nine edible plants showed marked variations, ranging from 12.2 to 80.1 mg gallic acid equivalent/g extract, 2.34 to 13.65 mg quercetin equivalent/g extract, and 97.2 to 460.1 mg catechin equivalent/g extract, respectively. Our findings showed that grape seed, Cat's whiskers and Sweetleaf extract were the most effective pancreatic α-amylase, intestinal maltase, and sucrase inhibitor with IC₅₀ values of 0.29 ± 0.01 mg/ml, 0.97 ± 0.10 mg/ml and 0.86 ± 0.01 mg/ml, respectively. All extracts (1 mg/ml) markedly inhibited the glycation of bovine serum albumin in fructose-mediated non-enzyme glycation by 50–30% at week 1. It was found that Pennywort maintained the high percentage inhibition among those of the extracts during the 4 weeks of experiment. These edible plants may be used for controlling blood glucose level and prevention of the development of type 2 diabetes.     

Fermented soybean-derived water-soluble Touchi extract inhibits alpha-glucosidase and is antiglycemic in rats and humans after single oral treatments

A water-soluble extract of Touchi, a traditional Chinese food, was found to exert a strong inhibitory activity against rat intestinal alpha-glucosidase. We orally administered sucrose (2 g/kg) with or without Touchi extract (TE) to normal rats at 100 and 500 mg/kg. Postprandial increases in blood glucose levels at 30 and 60 min after the administration of TE were significantly depressed compared with controls. In humans, eight borderline diabetic subjects were administered 0.1-10.0 g TE before sucrose loading (75 g). TE decreased the glycemic response dose dependently after sucrose loading. Compared with the area under the curve of the postprandial rise in blood glucose with various doses, TE elicited a significant antiglycemic effect at a minimum effective dose of 0.3 g. In addition, when four diabetics were administered 0.3 g TE before eating 200 g of cooked rice, the postprandial increases in blood glucose and mean insulin levels were significantly depressed at 60 and 120 min, respectively, after ingestion compared with levels when no TE was administered. TE, which exhibits alpha-glucosidase inhibitory activity, demonstrated an antihyperglycemic effect and may have potential use in the management of patients with non-insulin-dependent diabetic mellitus.     

苦瓜水提取物降血糖作用动物实验研究

目的观察苦瓜水提取物对II型糖尿病小鼠的降血糖作用。方法采用高脂饲料喂饲断乳小鼠制备II型糖尿病模型,选血糖≥8 mmol/L者分入对照组和2个剂量组。剂量组分别给予0.25、1.00 g/kg.bw剂量的苦瓜水提取物。30 d后测定小鼠空腹血糖、糖耐量、血生化指标和血清MDA、SOD。同步给予正常小鼠1.00 g/kg.bw剂量的苦瓜水提取物观察其对正常小鼠血糖的影响。结果苦瓜水提取物0.25 g/kg.bw剂量能显著降低高血糖小鼠空腹血糖,显著提高实验前后血糖下降百分率(P0.01),对高血糖小鼠的糖耐量无显著影响。1.00 g/kg.bw剂量能改善高血糖小鼠血清胆固醇升高的状态,对升高的血清MDA有降低作用。但进一步加剧了高血糖小鼠血清总蛋白、白蛋白降低的状态。苦瓜水提取物对正常小鼠的血糖无显著影响。结论苦瓜水提取物可降低II型糖尿病小鼠的高血糖,但可导致血清总蛋白、白蛋白降低。临床上应用时应加注意。     

d-Sorbose inhibits disaccharidase activity and demonstrates suppressive action on postprandial blood levels of glucose and insulin in the rat

In an attempt to develop d-sorbose as a new sweetener that could help in preventing lifestyle-related diseases, we investigated the inhibitory effect of d-sorbose on disaccharidase activity, using the brush border membrane vesicles of rat small intestines. The inhibitory effect was compared with that of l-sorbose and other rare sugars, and the small intestinal disaccharidases in rats was compared with that of humans as well. In humans and the small intestines of rats, d-sorbose strongly inhibited sucrase activity and weakly inhibited maltase activity. Inhibition by d-sorbose of sucrase activity was similar to that of l-arabinose, and the K_i of d-sorbose was 7.5 mM. Inhibition by d-sorbose was very strong in comparison with that of l-sorbose (K_i, 60.8 mM), whereas inhibition of d-tagatose was between that of d-sorbose and l-sorbose. The inhibitory mode of d-sorbose for sucrose and maltase was uncompetitive, and that of l-sorbose was competitive. To determine a suppressive effect on postprandial blood levels of glucose and insulin via inhibition of sucrase activity, sucrose solution with or without d-sorbose was administered to rats. Increments in the blood levels of glucose and insulin were suppressed significantly after administration of sucrose solution with d-sorbose to rats, in comparison to administration of sucrose solution without d-sorbose. In contrast, the suppressive effect of l-sorbose on postprandial blood levels of glucose and insulin was very weak. These results suggest that d-sorbose may have an inhibitory effect on disaccharidase activity and could be used as a sweetener to suppress the postprandial elevation of blood levels of glucose and insulin. The use of d-sorbose as a sweetener may contribute to the prevention of lifestyle-related diseases, such as type 2 diabetes mellitus.     

Mulberry leaf extract reduces postprandial hyperglycemia with few side effects by inhibiting α-glucosidase in normal rats

Mulberry (Morus alba L.) leaf extract (MLE) was investigated as a potent plant-derived α-glucosidase inhibitor with low α-amylase inhibitory activity. MLE was prepared by heating in an autoclave at 121 °C for 15 minutes, and its in vitro and in vivo antihyperglycemic activities were investigated. The adverse side effects of MLE were analyzed by measuring the weight and volume of the cecum, stool color, starch content in the cecum, and the integrity of intestinal transporting capacity. The in vitro inhibitory activity of MLE on intestinal α-glucosidase was potent and that on intestinal α-amylase was very weak compared with acarbose. Sugar loading tests with starch, maltose, and sucrose showed that MLE may reduce postprandial increases in blood glucose by acting as an intestinal α-glucosidase inhibitor. Feeding tests suggested that MLE may exhibit fewer adverse side effects than other α-glucosidase inhibitors, such as abdominal flatulence and meteorism, which are attributed to the impaired digestion of starch by strong inhibition of intestinal α-amylase. These results suggest that MLE could be used in the development of pharmaceutical foods to control the blood glucose levels of diabetic patients by inhibiting intestinal α-glucosidase with reduced side effects.     

Quantitative relationship between intestinal sucrase inhibition and reduction of the glycemic response to sucrose in rats

We have investigated the quantitative relationship between sucrase inhibition and reduction in the 0-3 h glycemic response to an oral dose of sucrose in rats. Castanospermine is a quasi-irreversible sucrase inhibitor that did not dissociate from sucrase during tissue preparation or assay for sucrase activity. An oral dose of castanospermine (0.1-3.0 mg/kg body wt) dose-dependently reduced sucrase activity of intestinal segments by 15-90%; 0.4 mg/kg body wt reduced total sucrase activity about 50%. The lower doses inhibited sucrase much more extensively in the proximal than in the distal segments. Castanospermine also dose-dependently reduced the 0-3 h glycemic response to sucrose; 1.5 mg/kg body wt reduced the glycemic response about 50%. Each submaximal castanospermine dose inhibited total sucrase activity more than it reduced the glycemic response. We conclude that intestinal sucrase activity in the rat is in modest excess relative to the rate-determining step of glucose absorption following sucrose administration. Fourteen days of castanospermine treatment (0.2 mg.kg body wt-1.d-1) resulted in sucrase inhibition that was similar to a single castanospermine treatment, suggesting that castanospermine treatment resulted in neither cumulative sucrase inhibition nor induction of sucrase activity.     

Blood glucose and insulin concentrations are reduced in humans administered sucrose with inosine or adenosine

Recently we found that some nucleosides such as inosine or adenosine inhibited alpha-glucosidase from rat intestine. The aim of this study was to determine whether these nucleosides are sucrase inhibitors in humans as well as rats. Blood glucose and insulin responses were examined in 23 healthy volunteers (18 males and 5 females) administered sucrose with inosine and 8 (males) administered sucrose with adenosine. The initial increase in plasma glucose and serum insulin concentrations at 30 min after loading sucrose (50 g) alone were significantly reduced by co-administration of inosine (2.5 and 1.0 g) or adenosine (2.5 g). The total increases in the areas under the plasma glucose and serum insulin concentration curves for 3 h after administration of the same amount of sucrose with inosine were also significantly less than those when the volunteers were administered sucrose alone. These results in humans agree with the findings obtained in our previous studies in rats. These nucleosides may be used as one of the components of artificial sweeteners when mixed with sucrose and may be useful as food additives to suppress increases in blood glucose and insulin.     

Inhibitory activity of Euonymus alatus against alpha-glucosidase in vitro and in vivo

The major goal in the treatment of diabetes mellitus is to achieve near-normal glycemic control. To optimize both fasting blood glucose and postprandial glucose levels is important in keeping blood glucose levels as close to normal as possible. α-Glucosidase is the enzyme that digests dietary carbohydrate, and inhibition of this enzyme could suppress postprandial hyperglycemia. The purpose of this study was to test the inhibitory activity of methanol extract of Euonymus alatus on α-glucosidase in vitro and in vivo to evaluate its possible use as an anti-diabetic agent. Yeast α-glucosidase inhibitory activities of methanol extract of E. alatus were measured at concentrations of 0.50, 0.25, 0.10, and 0.05 mg/ml. The ability of E. alatus to lower postprandial glucose was studied in streptozotocin-induced diabetic rats. A starch solution (1 g/kg) with and without E. alatus extract (500 mg/kg) was administered to diabetic rats by gastric intubation after an overnight fast. Plasma glucose levels were measured at 30, 60, 90, 120, 180, and 240 min. Plasma glucose levels were expressed in increments from baseline, and incremental areas under the response curve were calculated. Extract of E. alatus,which had an IC₅₀ value of 0.272 mg/ml, inhibited yeast α-glucosidase activity in a concentration-dependent manner. A single oral dose of E. alatus extract significantly inhibited increases in blood glucose levels at 60 and 90 min (p<0.05) and significantly decreased incremental response areas under the glycemic response curve (p<0.05). These results suggest that E. alatus has an antihyperglycemic effect by inhibiting α-glucosidase activity in this animal model of diabetes mellitus.