茶多酚对大鼠晶状体醛糖还原酶的抑制作用

目的观察茶多酚对大鼠晶状体醛糖还原酶的抑制作用。方法从大鼠晶状体中提取醛糖还原酶,酶活性测定反应体系包括底物DL-甘油醛,辅酶NADPH,缓冲液PBS和醛糖还原酶。反应温度37℃,反应时间3min,340nm处测吸光度值。测定组加入醛糖还原酶抑制剂,比较槲皮素与芦丁、槲皮素与茶多酚、茶多酚与EGCG、ECG、EGC、EC、GC对醛糖还原酶的抑制作用。结果IR50槲皮素相似文献   

金樱根不同提取部位对宫颈癌Hela细胞抑制作用的研究

目的:研究金樱根不同溶剂提取物对宫颈癌Hela细胞的抑制作用,筛选金樱根活性部位。方法:采用MTT法测定金樱根水提取物、乙醇提取物、乙酸乙酯提取物、三氯甲烷提取物对宫颈癌Hela细胞的抑制作用,计算每种溶剂提取物的半数抑制浓度(IC50)。结果:金樱根水提取物、乙醇提取物、乙酸乙酯提取物、三氯甲烷提取物IC50分别为:15.18μg/ml,6.38μg/ml,26.39μg/ml,73.48μg/ml。结论:金樱根水提取物、乙醇提取物、乙酸乙酯提取物,三氯甲烷提取物对宫颈癌细胞均具有一定的抑制作用,其中乙醇提取物体外对宫颈癌Hela细胞的杀伤作用最强,能显著抑制Hela细胞的生长。     

狼毒大戟总提取物对乳腺癌细胞增殖及周期的影响

目的:观察狼毒总提取物对乳腺癌细胞增殖及周期影响。方法:CCK-8法测定该药对MCF-7、MDAMB-231、SK-Br-3细胞株增殖影响,流式细胞术检测狼毒总提取物对MCF-7细胞周期影响。结果:狼毒总提取物对细胞IC50浓度分别为227ug/ml、793ug/ml、1034ug/ml。药物作用随着药物浓度提高。MCF-7周期检测,G0/G1期期比例下降、S期比例上升。结论:狼毒提取物对MCF-7、MDA-MB-231、SK-Br-3细胞生长均有抑制作用。主要研究了MCF-7细胞抑制机制,提示狼毒大戟总提取物抑制MCF-7细胞G_2/M期到G_0/G_1其转换。     

鸡血藤提取物的抗肠道病毒作用

目的揭示鸡血藤提取物（aqueous extracts,AE）抑制肠道病毒的作用,以开发抗肠道病毒新药。方法采用细胞病变CPE和MTT比色法,测定鸡血藤提取物在Vero细胞的抗肠道病毒（EV enterovirus）的活性,其中肠道病毒包括对Coxsackie B3病毒、Coxsackie B5病毒、Echo9病毒、Echo29病毒和PolioⅠ病毒的抑制作用。同时采用BALB／c小鼠经腹腔注射感染Coxsackie B3病毒造成小鼠心肌炎模型,观察心指数、死亡率。最后,通过RT-PCR比较鸡血藤提取物体内外抑制Coxsackie B3病毒的mRNA表达的效果。结果不同质量比鸡血藤提取物对上述5种病毒均呈现不同程度的抗病毒作用。鸡血藤提取物在Vero细胞中抑制Coxsackie B3病毒、Coxsackie B5病毒、Echo9病毒、Echo29病毒和PolioI病毒的半数抑制浓度（IC50）分别为60．8、47．1、14．8、65．5、29．1μg／mL。鸡血藤提取物的药物治疗指数（Therapeutic index,TI=CC50／IC50）分别为4．1、5．3、16．9、3．8和8．6。鸡血藤提取物对Coxsackie B3病毒的mRNA的表达有抑制作用,同时该提取物对于由Coxsackie B3病毒引发的病毒心肌炎有明显的抑制作用,并可降低小鼠的死亡率。结论鸡血藤提取物对肠道病毒具有抑制作用。     

槲皮素抑制体外培养的人眼晶状体上皮细胞生长的研究

目的研究槲皮素对体外培养的人眼上皮细胞的抑制作用。方法时先天性白内障患者术中环行撕前囊膜，进行原代培养并传代，取第二代细胞用于实验，MTT法观察不同浓度的槲皮素（10μmol／ml、20μmol／ml、40μmol／ml、80μmol／ml、160μmol／m1）对晶状体上皮细胞的粘附的抑制作用；对基本融合的细胞进行划线，160μmol／ml的槲皮素进行干预，细胞计数法观察裸露区内细胞的移行数量；MTT法测定槲皮素对晶状体上皮细胞增殖的抑制效应。结果不同浓度的槲皮素（40μmol／ml、80μmol／ml、160μmol／m1）对晶状体上皮细胞的粘附和增殖具有抑制作用。160μmol／ml槲皮素明显抑制其移行。结论槲皮素对体外培养的人眼晶状体上皮细胞具有抑制作用，安全有效。     

鸡血藤水提物体外抗肠道病毒作用研究

目的揭示鸡血藤提取液体外抑制肠道病毒的作用。方法采用细胞病变抑制试验、MTT比色法,以病毒唑为阳性对照药,测定了鸡血藤水提液AE(aqueous extracts)对Vero E6细胞的细胞毒性,并在对细胞的最大无毒浓度下观察不同浓度的提取液AE在Vero E6细胞中对5种肠道病毒的抑制作用,计算药物半数有效浓度(50%inhibition con-centration,IC50)和药物治疗指数(therapeutic index,TI)。在此基础上采用分组实验初步探讨了提取物样品的抗病毒机制。结果提取物AE半数中毒浓度(CC50)为≥250.0 ug/ml;抑制肠道病毒柯萨奇病毒B3、B5、埃可病毒Echo 9、Echo 29、脊髓灰质炎病毒Polio virusⅠ的IC50分别为60.8、47.1、14.8、65.52、9.1 ug/ml,TI分别为4.1、5.3、16.9、3.8、8.6,对肠道病毒的抑制作用存在量效反应关系;机制研究表明,AE在与CVB3的四种分组作用方式中均呈现不同程度的抗病毒作用。结论鸡血藤抗病毒提取液AE在Vero E6细胞中对肠道病毒有明显的抑制作用;鸡血藤水提物AE不仅具有直接杀灭CVB3病毒作用,而且还可进入细胞或吸附在细胞表面,从而达到抑制或杀伤病毒的效果。     

黄连素对糖尿病大鼠组织醛糖还原酶活性及心肌氧化应激、细胞凋亡的影响

目的研究醛糖还原酶活性、氧化应激、细胞凋亡与糖尿病心肌病变的关系,探讨黄连素对醛糖还原酶活性的抑制效果及对糖尿病大鼠心肌病变的保护作用。方法将Wistar大鼠分为正常对照组、糖尿病组、糖尿病黄连素治疗组,检测超氧化物歧化酶（SOD）活性水平及丙二醛（MDA）含量,采用核苷酸末端转移酶介导DUTP末端标记技术（TUNEL）检测心肌细胞的凋亡率。结果 （1）糖尿病组醛糖还原酶活性较正常对照组均明显升高（P〈0.01）,黄连素治疗组醛糖还原酶活性较糖尿病组均明显降低（P〈0.01）。（2）糖尿病组较正常对照组心肌MDA含量均明显增高（P〈0.01）,SOD活性水平明显降低（P〈0.01）;黄连素治疗组较糖尿病组MDA含量降低（P=0.000）,SOD活性水平升高（P=0.000）。（3）糖尿病组心肌细胞凋亡率明显高于正常对照组（P〈0.01）;黄连素治疗组较糖尿病组凋亡率降低（P〈0.01）。结论醛糖还原酶活性增高可能通过氧化应激及细胞凋亡参与了糖尿病心肌病变的发生发展,黄连素可以明显改善糖尿病大鼠的心肌损害。     

低分子多糖对小鼠移植性肿瘤抑制作用的研究

目的探讨低分子多糖对小鼠移植性肿瘤抗癌作用的研究。方法体内抑瘤试验，体外细胞毒试验，小鼠腹腔巨噬细胞吞噬鸡红细胞试验，NK细胞活性试验。结果低分子多糖对小鼠移植性肿瘤的抑制率在30．31％～52．19％。对K562白血病细胞株半数抑制浓度IC50为20μg／ml，对Hela宫颈癌细胞株半数抑制浓度IC50为23．4μg／ml。并能明显提高小鼠腹腔巨噬细胞吞噬鸡红细胞吞噬百分率和吞噬指数。结论低分子多糖对小鼠移植性肿瘤有一定的抑制作用。     

富含anthocyanin的水果提取物对血管内皮细胞产生PGE2的影响研究

目的研究富含anthocyanin的水果提取物对血管内皮细胞产生PGE2的影响。方法将人类正常的血管内皮细胞CRL-2606在Kaighn’s F12K培养基中（补加有10％FBS，0．1mg／ml肝素，0．03mg／ml的ECGS，50μg／ml链霉素和500U／ml青霉素）37℃、5％CO2的条件下培养至接近融合，然后在含有从水果中提取出的anthocyanin的F12K培养基中添加或不添加100ng／mlLPS，继续培养18小时，测定细胞生存率，并将培养液离心，收集上清液，用STAT-Prostaglandin E2 EIA Kit试剂盒测定培养基上清液中的PGE2浓度。结果当CRL-2606细胞暴露于300μg／ml或以上的Chokeberry提取物中时，细胞的生存率低于60％，且表现出一定的剂量效应关系。而50～400μg／ml的蓝莓提取物和100～700μg／ml的黑醋栗提取物未显示细胞毒性。LPS刺激可使细胞PEG2释放量增加一倍以上，蓝莓提取物可明显抑制由于LPS刺激引起的PGE2释放增加，100μg／ml的蓝莓提取物可完全抑制此作用而使其含量维持于正常水平。700μg／ml的黑醋栗提取物对处于LPS刺激下的CRL-2606细胞具有一定的抑制PGE2释放作用。而对于处于LPS刺激下的细胞，500tμg／ml以上的Chokeberry提取物能抑制PGE2的释放。结论富含anthocyanin的黑醋栗、蓝莓以及Chokeberry提取物可以抑制由LPS刺激引起的血管内皮细胞释放PEG2增加的作用，具有一定的抗炎、抗氧化作用。     

三七多糖抗氧化活性研究

目的:探讨三七多糖的体外抗氧化活性。方法:三七粗多糖经Sevage法纯化后用苯酚—硫酸法测定其含量,并采用还原/抗氧化能力、清除DPPH自由基、OH自由基和ABTS+自由基能力考察三七多糖的抗氧化能力。结果:三七多糖含量为80.49 mg/g;与对照品BHA和茶多酚相比较,还原/抗氧化能力和清除DPPH自由基能力(FRAP=11586.3μmol/g、IC50=0.055 mg/ml)都比茶多酚(FRAP=6507.5μmol/g、IC50=0.143mg/ml)强,但都比BHA(FRAP=1536.5μmol/g、IC50=0.030 mg/ml)弱;清除羟基自由基能力比BHA(IC50=0.028 mg/ml)及茶多酚(IC50=0.002 mg/m L)都强;清除ABTS+自由基能力(IC50=0.018 mg/ml)比BHA(IC50=0.175 mg/ml)强,但比茶多酚(IC50=0.002 mg/ml)弱。结论:三七多糖具有较强的抗氧化能力,为其生物活性的深入研究提供了参考依据。     

原子吸收光谱法测定中草药中微量元素

研究了微波消解法处理样品,用火焰原子吸收光谱法测定了金银花、黄柏、生地、蒲公英、连翘、板蓝根、车前草、决明子等清热解毒类中草药中的铜、锌、锰、钙、镁、铁6种微量元素。结果表明:清热解毒中草药中钙、镁、铁含量较为丰富,加标回收率为97.28%~101.4%,RSD为0.81%~1.73%。结果令人满意。     

Design and synthesis of potent and selective aldose reductase inhibitors based on pyridylthiadiazine scaffold

A series of pyrido[2,3-e]-[1,2,4]-thiadiazine 1,1-dioxide acetic acid derivatives were synthesized and tested for their inhibitory activity against aldose reductase (ALR2). These derivatives were found to be potent aldose reductase inhibitors with IC₅₀ values ranging from 0.038 μM to 11.29 μM. Most but not all of them showed a strong ALR2 inhibition activity and significant selectivity, which were further supported by docking studies. Of these inhibitors, compound 7d exhibited highest inhibition activity. Structure-activity relationship studies indicate the requirement of N2-benzyl group with electron-withdrawing substituents and N4-acetic acid group in the pyridothiadiazine scaffold.     

The inhibitory activities of the edible green alga Capsosiphon fulvescens on rat lens aldose reductase and advanced glycation end products formation

Purpose

Accumulating evidence suggests that inhibitors of aldose reductase (AR) may prevent hyperglycemia-induced long-term complications in diabetes mellitus. In the present study, we evaluated the AR inhibitory potential of ethanolic (EtOH) extracts from 22 seaweed species.

Methods

AR inhibitory activities of the selected seaweed species were evaluated using the rat lens aldose reductase (RLAR) inhibitory assay.

Results

All extracts exhibited RLAR inhibitory activity, which ranged from 5.87 to 92.71 % at a concentration of 50 μg/mL. Since Capsosiphon fulvescens exhibited significant inhibitory potential and is a frequently used foodstuff, it was selected for a detailed investigation using RLAR and advanced glycation end products (AGE) formation inhibitory assays. Among the different solvent-soluble fractions, the CH₂Cl₂, EtOAc, and n-BuOH fractions showed promising RLAR and AGE formation inhibitory activities. Considering the AR inhibitory potential, CH₂Cl₂ and EtOAc fractions were selected for chromatographic separation and yielded 11 compounds in which capsofulvesin A, capsofulvesin B, and chalinasterol showed potential RLAR inhibitory activity with the respective IC₅₀ values of 52.53, 101.92, and 345.27 μM. Kinetic studies revealed that capsofulvesin A and chalinasterol exhibited mixed type inhibition, while capsofulvesin B exhibited noncompetitive inhibition. To our knowledge, this is the first report of AR inhibitory activity of the glycolipids capsofulvesin A and capsofulvesin B.

Conclusions

Our results clearly indicate the potential RLAR and AGE formation inhibitory activities of C. fulvescens as well as its isolated constituents, which could be further explored to develop therapeutic modalities for the treatment of diabetes and related complications.     

Synthesis and aldose reductase inhibitory activity of N-(quinolinyl thiocarbonyl) glycine derivatives

The onset of diabetic complications may be prevented by the inhibition of aldose reductase. Derivatives of N-(quinolinyl thiocarbonyl) glycine were prepared and their in vitro and ex vivo aldose reductase inhibitory activities were tested on rat lens. The cincophen derivatives were the most potent in vitro with an enzyme inhibition value of 29% at 10⁻⁸ M and 91% at 10⁻⁷ M for the N-[(2-phenylquinolin-4-yl)thiocarbonyl]-N-methylglycine compound 10a. This activity was shown to be dependent on the nature of the substituents and seems to be optimal for the acids; esters were found to be inactive. No compound have shown ex vivo inhibitory activity. It is concluded that the lack of ex vivo activity is likely due to a poor bioavailability or a bad penetration of the compounds in target tissue (lens).     

Determination of estrogenic/antiestrogenic potential of antifertility substances using rat uterine peroxidase assay.

The effect of three compounds (clomiphene citrate, centchroman, embelin) and plant-derived methanolic extracts (Abutilon indicum and Butea monosperma) was studied on uterotropic and uterine peroxidase activities in ovariectomized rats. It was observed that these two parameters were highly correlated in response to treatment with these test materials and also to estradiol. It was suggested that the uterine peroxidase assay could be utilized as a biochemical parameter in the screening of new antifertility agents for their estrogenic/antiestrogenic properties.     

Synthesis and aldose reductase inhibitory activity of a new series of 5-[[2-(ω-carboxyalkoxy)aryl]methylene]-4-oxo-2-thioxothiazolidine derivatives

Anew series of 5-[[2-(ω-carboxyalkoxy)aryl]methylene]-4-oxo-2-thioxothiazolidine derivatives was synthesized and evaluated for their potency as aldose reductase inhibitors (ARIs). Their activities were examined in terms of their inhibitory effect on rat lens aldose reductase in vitro and in terms of the preventive effect on sorbitol accumulation in the sciatic nerve of streptozotocin (STZ)-induced diabetic rats in vivo. Of these compounds, some of the naphthylmethylene thiazolidine derivatives were comparable to Zenarestat in the inhibitory potency in vitro and in vivo. In particular, compound 30 was 1.5 times more potent than Zenarestat in the in vivo activity, and had an adequate potency for clinical development.     

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.     

Alpha-glucosidase inhibitory and antioxidant activities of Vietnamese edible plants and their relationships with polyphenol contents

The prevention and treatment of non-communicable diseases by using the beneficial biological effects of polyphenolic plants have attracted increasing interest from nutritional scientists. The a-glucosidase inhibitory and antioxidant activities of aqueous and methanolic extracts from 28 common Vietnamese edible plants, comprising 4 groups (plants used for making drinks, edible wild vegetables, herbs, and dark green vegetables), were investigated in vitro. The polyphenol contents of these extracts were determined by the Folin-Ciocalteu method and calculated as catechin equivalents. The extracts from plants used for making drinks showed the highest activities for both a-glucosidase inhibition and as antioxidants, followed by edible wild vegetables, herbs, and dark green vegetables. Positive relationships among alpha-glucosidase inhibitory activities, antioxidant activities and polyphenol contents of these 28 edible plants were found in both aqueous and methanolic extracts. Four new promising materials that are similar to or better than guava leaf extract, including Syzygium zeylanicum, Cleistocalyx operculatus, Horsfieldia amygdalina and Careya arborea demonstrated high alpha-glucosidase inhibitory activity (93, 76, 68 and 67%, respectively) at the final concentration of 0.8 mg lyophilized material/mL solution and antioxidant activity (85, 87, 78 and 80%, respectively) at the final concentration of 30 pg lyophilized material/mL solution. These four edible plants contained significantly high polyphenol contents (equivalent to 251.7, 146.6, 136.6 and 168.6 mg of catechin/g dry weight, respectively). Thus, these four materials might be possible new sources of a-glucosidase inhibition and antioxidants suitable for use as functional foods in the future.     

Effects of commonly consumed fruit juices and carbohydrates on redox status and anticancer biomarkers in female rats

Administration of apple juice, black currant juice, or a 1:1 combination of the two juices significantly decreased the level of the lipid peroxidation biomarker malondialdehyde in plasma of female rats, whereas the protein oxidation biomarker 2-amino-adipic semialdehyde, was significantly increased following administration of orange juice, black currant juice, or the 1:1 combination of apple and black currant juice. A significant increase in 2-amino-adipic semialdehyde was also observed in control rats given sucrose, fructose, and glucose in the drinking water at concentrations approximating the average carbohydrate levels in the employed fruit juices. None of the fruit juices were found to affect the activities of antioxidant enzymes in red blood cells or hepatic glutathione S-transferase. Hepatic quinone reductase activity, on the other hand, was significantly increased by grapefruit juice, apple juice, and black currant juice. The total daily intake of a selected subset of flavonoid aglycones ranged from 0.2 to 4.3 mg, and quercetin was found to be a minor constituent of all the juices investigated. In a parallel study, rats were fed quercetin at doses ranging from 0.001 to 10 g/kg of diet. However, no effects were observed on hepatic glutathione S-transferase or quinone reductase activities, plasma redox status, or the activity of red blood cell antioxidant enzymes. Overall, the results of the present study suggest that commonly consumed fruit juices can alter lipid and protein oxidation biomarkers in the blood as well as hepatic quinone reductase activity, and that quercetin may not be the major active principle. The observation that natural carbohydrates are capable of mediating oxidative stress in vivo warrants further studies due to the central role refined and unrefined carbohydrates play in human nutrition.