4种海星的α-葡萄糖苷酶抑制活性研究

目的寻找具有降糖活性作用的海星并确定其活性部位。方法首先采用正常和糖尿病小鼠口服糖耐量试验,比较4种海星粗提物改善口服糖耐量的作用,然后利用体外α-葡萄糖苷酶抑制剂模型进一步确定具有改善口服糖耐量作用的海星中抑制α-葡萄糖苷酶的活性部位。结果罗氏海盘车粗提物对正常小鼠和糖尿病小鼠餐后0.5、1 h血糖均有显著降低作用,其中的正丁醇部位具有很强的α-葡萄糖苷酶抑制活性。结论罗氏海盘车的正丁醇部位具有α-葡萄糖苷酶抑制作用。     

降糖中药对α-葡萄糖苷酶抑制作用的研究

目的：探讨降糖中药对α-葡萄糖苷酶活力的影响。方法：中药水提液通过浸泡、离心、脱色等方法制备;酶活性用PNPG法测定。结果：五味子、虎杖对α-葡萄糖苷酶有强烈的抑制作用。结论：五味子、虎杖可能具有拜糖平样的降糖作用。     

复方石斛饮品及其主要原料对α-葡萄糖苷酶抑制活性的体外研究

目的建立体外α-葡萄糖苷酶抑制活性评价体系,探讨复方石斛饮品及其主要原料的降糖机制,评价复方石斛饮品的降血糖作用。方法优化抑制剂对α-葡萄糖苷酶抑制活性的测定条件,以阿卡波糖为阳性对照,以复方石斛饮品及铁皮石斛、桑叶、桑椹水提液为抑制剂样品,测定它们对α-葡萄糖苷酶抑制活性作用,计算抑制率和半数抑制浓度(IC_(50))。结果复方石斛饮品及铁皮石斛、桑叶、桑椹水提液均有α-葡萄糖苷酶抑制活性,半数抑制浓度(IC_(50)):复方石斛饮品41.5 mg/m L、铁皮石斛水提液87.9 mg/m L、桑叶10.8 mg/m L、桑椹15.4 mg/m L、阿卡波糖24.1 mg/m L。抑制活性作用强弱顺序为:桑叶>桑椹>复方石斛饮品>铁皮石斛。复方石斛饮品在高浓度150 mg/m L时抑制率(83.3%)与阿卡波糖抑制率(85.1%)接近。结论桑叶、桑椹水提液抑制α-葡萄糖苷酶活性作用最强,可作为α-葡萄糖苷酶抑制剂产品开发原料;铁皮石斛水提液对α-葡萄糖苷酶抑制活性作用最弱,其降血糖效果可结合其他方法进行评价;复方石斛饮品通过将铁皮石斛与桑叶、桑椹等降糖中药的有机配伍,合理工艺生产加工,对α-葡萄糖苷酶有明显的抑制活性作用,具有降血糖作用。     

基于HPLC-ESI-QTOF-MS技术的金桂花降糖活性物质基础研究

本文通过体外对α-葡萄糖苷酶活性、糖基化产物形成及抗氧化能力的影响,综合评价了金桂花水提物的降糖活性,并采用高效液相色谱-电喷雾-四极杆飞行时间串联质谱(HPLC-ESI-QTOF-MS)技术对金桂花水提物的主要化学成分进行了定性分析。体外药理活性研究表明,金桂花水提物对α-葡萄糖苷酶具有显著的抑制活性,抑制率(IC₅₀=2.11±0.26 mg·mL^-1)与阿卡波糖相当(IC₅₀=2.88±0.32 mg·mL^-1);同时具有一定的抑制糖基化产物和抗氧化能力。金桂花水提物中化合物质谱定性分析主要参考对照品毛蕊花糖苷质谱裂解规律和相关文献,鉴定出其中73个化合物,包括58个苯乙醇苷类化合物,8个咖啡酰奎宁酸类化合物,1个黄酮类化合物和几个植物中常见有机化合物。本研究初步推测61种为桂花中首次发现的化合物,其中8个目前尚无法鉴定结构的生物碱类化合物。研究结果为进一步阐明金桂花的降糖活性成分及制定科学的桂花质量控制标准提供了科学依据。     

栝楼提取物的α-葡萄糖苷酶抑制活性研究

目的初步考察栝楼提取物对α-葡萄糖苷酶活性的影响。方法以阿卡波糖为阳性对照,测定栝楼提取物的酶抑制率。结果栝楼提取物对α-葡萄糖苷酶活性有不同程度的抑制作用,其中栝楼乙酸乙酯提取物对α-葡萄糖苷酶的抑制作用略强于阿卡波糖,IC50为0.336g·L-1。结论栝楼提取物在体外对α-葡萄糖苷酶均具有一定的抑制作用,有望开发成一种新的降糖药物。     

甲壳低聚糖对α-葡萄糖苷酶活性的影响及降血糖作用

目的探讨甲壳低聚糖对α-葡萄糖苷酶活性的影响及降糖效果。方法在体外建立标准酶反应体系,分别加入6%甲壳低聚糖50,100,150,200,250,300μl,用4-硝基酚-α-D呋喃葡萄糖苷法测定酶活性;再建立加有6%阿卡波糖200μl的酶反应体系,测定酶活性;以250 mg/(kg.d)剂量灌胃,观察其对实验性糖尿病大鼠空腹及餐后血糖的影响。结果甲壳低聚糖对α-葡萄糖苷酶具有明显抑制作用,抑制效果接近于阿卡波糖;甲壳低聚糖能显著降低糖尿病大鼠空腹及餐后血糖。结论甲壳低聚糖可能具有阿卡波糖样的降血糖作用。     

山茱萸醇提液对D-半乳糖致衰大鼠非酶糖化及AR活性的影响

目的：研究山茱萸醇提液对D-半乳糖致衰大鼠体内非酶糖化和醛糖还原酶活性(AR)的影响。方法：本实验以D-半乳糖致衰大鼠为研究对象，分别以大、小剂量的山茱萸醇提液灌胃6周，测定了青年大鼠、致衰大鼠糖化血清蛋白(GSP)、糖化血红蛋白(GHb)、胸主动脉糖基化终末产物(AGE)含量、AR的变化，同时观察不同剂量山茱萸醇提液对致衰大鼠上述指标的影响，结果：致衰大鼠GSP、GHb、AGE含量随龄增加；醛糖还原酶活性增高。山茱萸醇提液可降低GSP、GHb、AEG含量，对醛糖还原酶活性无明显影响。结论：山茱萸醇提液可抑制体内蛋白质非酶糖化，具有一定抗衰老作用。     

中药提取物对鼠肠α-葡萄糖苷酶抑制作用的研究

目的 评估中药提取物对鼠肠α-葡萄糖苷酶的抑制作用.方法 从治疗糖尿病的中药方剂中选出常用的54味中药,水煎煮及煎煮后残渣以70％乙醇提取,各提取物进行α-葡萄糖苷酶体外抑制活性试验,探讨其对鼠肠α-葡萄糖苷酶的抑制作用,并与阳性对照药物阿卡波糖比较.结果 与阿卡波糖相比,桑枝等9味中药水煎煮液乙醇提取物对鼠肠α-葡萄糖苷酶的抑制作用显著,其中马齿笕、桑葚,桑枝和桑白皮这4味中药水煎煮液乙醇提取物对鼠肠α-葡萄糖苷酶抑制作用较强,抑制率分别为81.45％、72.35％、62.72％和63.93％,相应的阿卡波糖的抑制率为39.56％.结论 中药水煎煮液乙醇提取物对鼠肠α-葡萄糖苷酶有较好的抑制作用,对新型降糖中成药品种开发具有很好的参考价值.     

中药降糖药理

目的　中药治疗糖尿病应用前景十分广阔 ,能从多渠道、多层面作用于糖尿病的多种症状和并发症 ,如具有刺激胰岛 β细胞分泌胰岛素、增加胰岛素受体的敏感性、抑制葡萄糖的吸收、改善脂肪酸代谢等。中药的降糖机制与调节机体的免疫功能、提高胰岛素与其受体结合相关 ;另外醛糖还原酶抑制作用、蛋白质非酶糖基化抑制作用为中药显示了良好的降糖前景。     

盐知母化学成分α-葡萄糖苷酶抑制作用研究

目的对盐知母化学成分α-葡萄糖苷酶抑制作用进行比较研究,以探讨盐知母降血糖作用的增效原理,为后期研发提供科学依据。方法采用高效液相色谱法,以PNPG(对硝基苯基α-D-吡喃葡萄糖苷)为底物比较盐知母化学成分对α-葡萄糖苷酶的抑制作用。结果从盐知母氯仿层中分离得到的顺-扁柏树脂酚,对α-葡萄糖苷酶具有良好的抑制作用,且优于阿卡波糖的作用。同时芒果苷、知母皂苷AⅢ等盐知母的增量成分对α-葡萄糖苷酶抑制作用也相对较强。结论盐知母活性部位氯仿层分离物,顺-扁柏树脂酚对α-葡萄糖苷酶具有较高的抑制活性,提示盐知母活性部位分离物顺-扁柏树脂酚在抗糖尿病产品开发方面具有很好的应用前景。     

葛根素对D-半乳糖诱导大鼠抑制蛋白非酶糖基化及增强胰岛素敏感性的作用

目的观察葛根素对D-半乳糖(D-gal)诱导大鼠体内蛋白非酶糖基化反应、胰岛素抵抗、糖耐量和醛糖还原酶(AR)活性的作用。方法除空白对照组外,其余大鼠均采用腹腔注射(ip)D-gal150mg/kg,1次/d×56d致病,D-gal处理大鼠2周后,将大鼠按体重均衡随机分成:模型对照、葛根素和氨基胍3组,然后继续ipD-gal处理同时灌胃给予葛根素和氨基胍(每10ml300mg/kg)或蒸馏水,1次/d×42d;实验结束时,观察葛根素和氨基胍对D-半乳糖诱导大鼠体内晚期糖基化终末产物(AGEs)、糖化血红蛋白(HbA1c)、果糖胺(FRA)、糖耐量、血糖和胰岛素含量,并计算胰岛素敏感指数(ISI),以及醛糖还原酶(AR)活性的作用。结果与空白对照组比较,D-gal处理大鼠出现血糖升高、糖耐量减退(IGT)、糖基化产物(包括HbA1c,FRA和AGEs)和胰岛素含量增高,ISI降低,以及红细胞内AR活性增强(P<0.01);葛根素和氨基胍均能改善D-gal诱导大鼠IGT和降低空腹血糖、糖基化产物和胰岛素含量(P<0.01～0.05),提高ISI(P<0.01),并明显抑制AR活性(P<0.01～0.05)。结论D-gal能诱导大鼠体内糖基化反应、高胰岛素血症、胰岛素抵抗和醛糖还原酶活性增强;而葛根素和氨基胍能抑制蛋白非酶糖基化反应和醛糖还原酶活性,提高胰岛素敏感性,改善高胰岛素血症,提示葛根素可用于治疗糖尿病某些慢性并发症。     

Effects of C-glycosylation on anti-diabetic,anti-Alzheimer’s disease and anti-inflammatory potential of apigenin

Apigenin has gained particular interests in recent years as a beneficial and health promoting agent because of its low intrinsic toxicity. Vitexin and isovitexin, naturally occurring C-glycosylated derivatives of apigenin, have been known to possess potent anti-diabetic, anti-Alzheimer’s disease (anti-AD), and anti-inflammatory activities. The present study was designed to investigate the anti-diabetic, anti-AD, and anti-inflammatory potential of apigenin and its two C-glycosylated derivatives, vitexin and isovitexin by in vitro assays including rat lens aldose reductase (RLAR), human recombinant aldose reductase (HRAR), advanced glycation endproducts (AGEs), protein tyrosine phosphatase 1B (PTP1B), acetylcholinesterase (AChE), butyrylcholinesterase (BChE), β-site amyloid precursor (APP) cleaving enzyme 1 (BACE1), and nitric oxide (NO), inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) in lipopolysaccharide (LPS)-induced RAW 264.7 cells. Among them, isovitexin was found as the most potent inhibitor against RLAR, HRAR, AGE, AChE, and BChE while vitexin showed the most potent PTP1B inhibitory activity. Despite the relatively weak anti-diabetic and anti-AD potentials, apigenin showed powerful antiinflammatory activity by inhibiting NO production and iNOS and COX-2 expression while vitexin and isovitexin were inactive. Therefore, it could be speculated that C-glycosylation of apigenin at different positions might be closely linked to relative intensity of anti-diabetic, anti-AD, and anti-inflammatory potentials.     

Aldose reductase and advanced glycation endproducts inhibitory effect of Phyllostachys nigra

To evaluate active principles for diabetic complications from the black bamboo leaves, Phyllostachys nigra, eight compounds were isolated and tested for their effects on rat lens aldose reductase and advanced glycation endproducts. As a result, luteolin 6-C-(6'-O-trans-caffeoylglucoside) was found to show a strong aldose reductase and advanced glycation endproducts inhibition. This compound showed antioxidative activity measured in Photochem apparatus. It is concluded, therefore, that luteolin 6-C-(6'-O-trans-caffeoylglucoside) (6), a flavone of this plant, have antioxidative as well as aldose reductase and advanced glycation endproducts inhibitory effects. As a result, this compound could be offered as a leading compound for further study as a new natural products drug for diabetic complications.     

Inhibitory effect of the compounds isolated from Rhus verniciflua on aldose reductase and advanced glycation endproducts

The aim of this paper was to evaluate active principles for diabetic complications from Rhus verniciflua. Nine compounds were isolated via bioactivity guided fractionation and isolation and tested for their effects on recombinant human aldose reductase and advanced glycation endproducts. Butein and sulfuretin isolated from ethyl acetate fraction were found to possess strongly both forms of aldose reductase and advanced glycation endproducts inhibition. The inhibitory activity of butein against a recombinant human aldose reductase (IC(50) value: 0.5 microM) was 2.6 times more potent that of epalrestat as a positive control (IC(50) value: 1.3 microM). The inhibitory potency of sulfuretin (IC(50) value: 124.7 microM) on advanced glycation end-products was about 10 times more potent that of aminoguanidine as a positive control (IC(50) value: 1231.0 microM). These compounds all displayed antioxidative activity which was measured by Photochem apparatus. It was concluded, therefore, butein and sulfuretin have antioxidative as well as aldose reductase and advanced glycation endproducts inhibitory effects. As a result, these compounds could be proposed as a leading compound for further study as a new natural products drug that could be used for diabetic complications.     

Synthesis of [5-(4-pyrrol-1-yl-benzoyl)-1 H-pyrrol-2-yl)]-acetic acid and in vitro study of its inhibitory activity on aldose reductase enzyme and on protein glycation

[5-(4-Pyrrol-1-yl-benzoyl)-1H-pyrrol-2-yl)]-acetic acid was synthesized in a Vilsmeier-Haack process and by other methods. The compound was found to inhibit the enzyme aldose reductase as well as the glycation process of proteins and could therefore be useful for the treatment of various pathological conditions.     

Presence of aldose reductase inhibitors in tea leaves

Water extract from commercial English tea has a potent inhibitory activity against human placenta aldose reductase (NADPH oxidoreductase, E.C.1.1.1.21.). Inhibitory activity was separated into five major fractions by one-step chromatography with a C-18 reverse phase column. The most active fraction was further subjected to reverse phase column chromatography. As a result, a well-known flavone-glycoside, isoquercitrin, was isolated as the most potent chemical. The inhibitory character of isoquercitrin for aldose reductase was a mix of uncompetitive and noncompetitive inhibitions, and its IC50 was 1 x 10(-6) M. In rat sciatic nerve tissue preparations, sorbitol accumulation in the presence of high concentrations of glucose (30 mM) was inhibited by 38% at 5 x 10(-4) M of isoquercitrin. The flavone-glycoside isoquercitrin is the active inhibitor of aldose reductase inhibitor present in English tea. Given the ability of aldose reductase inhibitors to prevent diabetic complications, an epidemiological study of the effect of tea consumption on the pathogenesis and progression of diabetic complications would be interesting.     

Vicenin 2 isolated from Artemisia capillaris exhibited potent anti-glycation properties

Vicenin 2, isolated from a traditionally used medicinal plant Artemisia capillaris, is a 6,8-di-C-glucoside of apigenin which has been previously reported to possess a wide variety of pharmacological activities including antioxidant, anti-inflammatory, anti-cancer, and hepatoprotective. However, there have not been any reports concerning its anti-diabetic potential until now. Therefore, in the present study, we evaluated the anti-diabetic potential of vicenin 2 via α-glucosidase, protein tyrosine phosphatase 1B (PTP1B), rat lens aldose reductase (RLAR), and advanced glycation end products (AGE) formation inhibitory assays. Vicenin 2 strongly inhibited α-glucosidase, PTP1B, and RLAR in the corresponding assays. In addition, vicenin 2 inhibited the formation of both fluorescent AGE and nonfluorescent AGE, e.g., CML, as well as the level of fructosamine in glucose–fructose-induced bovine serum albumin (BSA) glycation. In the test system, vicenin 2 suppressed glycation-induced protein oxidation by attenuating the formation of protein carbonyl groups as well as by inhibiting the modification of protein thiol groups. Moreover, vicenin 2 was found to be a potent inhibitor of glycation-induced formation of amyloid cross-β structures in BSA. Taken together, vicenin 2 might be a useful lead for the development of multiple target-oriented therapeutic modalities for the treatment of diabetes and diabetes-associated complications.     

糖尿病的药物治疗

目的近年,随着糖尿病发病率的日益上升,抗糖尿病药物越来越受到重视,本文主要介绍国内外治疗糖尿病的药物以及抗糖尿病药物的研究方向。为临床合理用药提供参考。方法参阅国外大量相关文献,进行归纳和总结。结果按作用机制和化学结构治疗糖尿病的药物主要有胰岛素促泌剂、胰岛素增敏剂、α-葡萄糖苷酶抑制剂、胰岛素及胰岛素类似物、二肽基肽酶-Ⅳ(DPP-Ⅳ)抑制剂、其他口服降糖药。在临床使用中,二甲双胍、格列齐特、阿卡波糖应用广泛,居主导地位。在糖尿病的治疗中,常常联合用药。结论糖尿病的发生、发展与酶功能的紊乱密切相关。与糖尿病关系较为密切的酶,包括α-葡萄糖苷酶、醛糖还原酶、一氧化氮合酶、血管紧张素转换酶、肉碱脂酰转移酶Ⅰ和Ⅱ、蛋白激酶C、二肽基肽酶Ⅳ、蛋白酪氨酸激酶、蛋白酪氨酸磷酸酶,这些酶都可能成为糖尿病治疗的靶点,是研发糖尿病治疗药物的新方向。     

Evaluation of the effect of aldose reductase inhibition on increased basement membrane collagen fluorescence in diabetic rats

1. It has been proposed that increased fructose contributes to the formation of fluorescent pigments in diabetic tissues. 2. Since the aldose reductase inhibitor sorbinil lowers glomerular fructose concentrations, we examined the effect of sorbinil on the formation of advanced glycation end products in glomerular basement membrane of streptozotocin diabetic rats. 3. Treatment with sorbinil for 30 days after induction of diabetes did not influence the increased fluorescence observed in collagen from glomerular basement membrane of untreated diabetic rats. 4. The results suggest that nonenzymatic glycation by fructose is not a major contributor to the formation of fluorescent advanced glycation end products in basement membrane in experimental diabetes.     

黄芩苷对D半乳糖诱导衰老大鼠拮抗脑老化糖基化氧化应激及胰岛素抵抗作用

目的 观察黄芩苷( baicalin,Bai)对D-半乳糖(D-gal)诱导大鼠体内蛋白非酶糖基化-氧化应激、醛糖还原酶(AR)活性、血糖、胰岛素抵抗(IR)及空间探索能力的作用.方法 除空白对照组外,其余大鼠均采用腹腔注射( ip) D-gal 150 mg·kg-1,qd×70d致病.D-gal处理大鼠28 d后,将大鼠按体重均衡随机分成5组,每组15只:模型对照组(二甲双胍150 ng·kg-1、氨基胍150 mg·kg-1)以及Bai高和低剂量组(300 ng·kg-1和150 mg·kg-1),然后继续ip D-gal处理,同时灌胃给予不同药物或蒸馏水(10ml·kg-1),qd×42 d;实验结束时,观察药物对D-半乳精诱导大鼠血糖(FBG)、果糖胺(FRA)、糖化血红蛋白(HbAlc)、晚期糖基化终末产物( AG Es)、胰岛素和丙二醛(MDA)含量,并计算胰岛素敏感指数(ISI),醛糖还原酶(AR)和超氧化物歧化酶( SOD)活性,以及测定Moris水迷宫空间探索能力的作用.结果 与空白对照组比较,D-gal处理大鼠出现FBG、FRA、HbAIc、AGEs和MDA及胰岛素含量增高,SOD活性和ISI降低,红细胞内AR活性增强(P＜0.01 );二甲双胍、氨基胍以及Bai高和低剂量,均能不同程度降低D-gal诱导大鼠FBG、FRA、HbAlc、AGEs和胰岛素含量(P＜ 0.01或0.05),提高ISI( P＜ 0.01),降低MDA含量而提高SOD活性,并明显抑制AR活性(P＜0.01或0.05),提高大鼠空间探索能力.结论 Bai能对抗D-gal致衰老大鼠IR,改善胰岛素敏感性,抑制糖基化-氧化应激反应、多元醇通路代谢以及炎症反应,改善大鼠空间探索能力.Bai的上述作用,呈量效关系.