苦瓜子中植物胰岛素的凝胶柱与RP-HPLC法分离

采用有机酸、醇提取,Sephadex G-50凝胶柱层析、反相高效液相色谱(RP-HPLC)技术分离,从苦瓜子中分离出降糖多肽PA,根据SDS-PAGE电泳和氨基酸组成分析,判定PA为植物胰岛素.     

胰岛素纳米粒的制备

目的：制备具有较高药物包封率的胰岛素纳米粒，方法：分别以海藻酸钠和索聚糖为包裹材料，制备海藻酸钠纳米粒和壳聚糖纳米粒，用透析法测定胰岛素包封率；考查海藻酸钠浓度及固化剂量对形成海藻酸钠纳米粒大小，包封率的影响；研究不同配比多聚磷酸钠对壳聚糖形成纳米粒理化性质的影响。结果：经筛选得到形成海藻酸钠纳米粒的最佳固化剂氯化钙配比，测得粒径为0．10um(D50)，选用合适浓度的多聚磷酸钠作为壳聚糖纳米粒的固化剂，测得粒径为0．13um(D50)，海藻酸钠纳米粒和壳聚糖纳米粒的胰岛素包封率分别达到89．3％和92．1％，结论：选用海藻酸钠及壳聚糖制备胰岛素的纳米粒，方法简便，药物包封率高。     

胰岛素壳聚糖纳米粒的制备

 目的制备胰岛素壳聚糖纳米粒。方法采用酶水解和超滤膜分离技术，得到不同相对分子质量的壳聚糖，由凝胶渗透色谱法测定其相对分子质量；采用溶剂扩散法制备纳米粒，研究纳米粒的空间结构，测定其粒径、表面电位(zeta电位)、模型药物胰岛素包封率及体外释放。结果通过控制酶水解条件，经超滤分离得到3种不同相对分子质量的壳聚糖，凝胶渗透色谱法测得的重均相对分子质量(MW)分别为10 289，41500和101 870。经溶剂扩散法制备得到的壳聚糖纳米粒，呈类圆形球体，粒径分布较窄，且随制备工艺中乙醇加入量的增加、分散用超声次数的增多，以及壳聚糖分子量的降低，粒径变小。壳聚糖纳米粒带正电荷，zeta电位值大于+30 mV。放射免疫法测得的药物包封率为72.66%。在壳聚糖酶存在条件下，前1 h体外释放药物较快，1 h后趋于平稳，并能持续释放6 h。结论选用合适相对分子质量壳聚糖制备胰岛素壳聚糖纳米粒，方法简便，药物包封率高，并有一定的缓释作用。     

苦瓜化学成分的研究

目的研究葫芦科苦瓜属植物苦瓜Momordica charantia的未成熟果实的化学成分。方法采用树脂柱纯化,硅胶柱色谱进行分离纯化,通过理化常数和光谱分析鉴定化合物的结构。结果从苦瓜的乙醇提取物中分离、鉴定了5个化合物的结构,分别是日耳曼醇乙酸酯(germanicyl acetate,Ⅰ)、苦瓜皂苷元(aglycone of momordico-sideⅠ,Ⅱ)、苦瓜皂苷元L(aglycone of momordicoside L,Ⅲ)、苦瓜苷(charantin,Ⅳ)、β-谷甾醇(β-sitosterol,Ⅴ)。结论化合物Ⅰ为首次从苦瓜属植物中分离得到,化合物Ⅱ为首次从苦瓜中分离得到新的天然产物,化合物Ⅲ为国内首次从苦瓜中分离得到。     

降血糖活性成分苦瓜皂苷的纯化工艺研究△

目的:研究苦瓜中降糖活性成分皂苷的纯化工艺.方法:以苦瓜苷计的总皂苷含量为指标,用正交试验和单因素试验等方法考查各工艺步骤的影响因素.结果:苦瓜的乙醇提取物经D-101大孔吸附树脂富集纯化后皂苷含量可达35%以上.结论:本纯化工艺可为苦瓜皂苷的工业化制备提供参考.     

苦瓜的药理与临床研究概况

苦瓜(Momordica charantia L.)又名凉瓜、癞瓜,为葫芦科苦瓜属植物的果实,具有清热、解凉,滋补强壮和降低血糖等作用,苦瓜含苦瓜甙(为β-谷甾醇-β-D-葡萄糖甙和5,25,-豆甾二烯醇-3-葡萄糖甙的等分子混合物)、苦瓜蛋白、5-羟基色胺、多种氨基酸、果胶、类胰岛素或称植物胰岛素(Plant insulin)等。近年来,对苦瓜的研究增多,并显示出苦瓜具有多种的药理作用。现概述于下。     

壳聚糖包覆葛根素脂质体的制备及理化性质考察

目的:制备壳聚糖包覆葛根素脂质体并对其理化性质进行考察。方法:采用逆相蒸发法制备葛根素脂质体,并用壳聚糖包覆。通过正交设计对制备工艺中影响脂质体包封率的主要因素进行优化;分别对未包覆脂质体和包覆脂质体的粒径分布、微观形态、Zeta电位、包封率进行考察。结果:未包覆和壳聚糖包覆葛根素脂质体均为圆形,包覆前后平均粒径分别为220.7 nm和632.6 nm,Zeta电位分别为-14.44 mV和 35.61 mV,包封率分别为50.6%和51.1%。结论:逆相蒸发法可以制备包封率较高且图整、平滑的葛根素脂质体。葛根素脂质体用壳聚糖包覆后粒径增加,表面电荷由负电荷变为正电荷。     

苦瓜、黄芪、黄芩苷对2型糖尿病模型大鼠胰岛素抵抗的影响

目的:观察苦瓜、黄芪、黄芩苷实验性2型糖尿病大鼠血糖、胰岛素和胰岛素敏感指数的影响。方法:用高热量饲料加小剂量链脲佐菌素(30mg/kg)建立实验性2型糖尿病大鼠模型后,用苦瓜、黄芪、黄芩苷治疗6周,测定空腹血糖,血清胰岛素,计算出胰岛素敏感指数。结果:苦瓜、黄芪、黄芩苷能降低实验性2型糖尿病大鼠空腹血糖、提高胰岛素敏感指数。结论:苦瓜、黄芪、黄芩苷具有改善实验性2型糖尿病大鼠胰岛素抵抗的作用。     

大蒜超氧化物歧化酶分离方法的研究

目的:从大蒜中提取分离超氧化物歧化酶(SOD)。方法:用丙酮沉淀法从蒜汁液中沉淀出粗品SOD,用自制的联有亚氨基二乙酸的联连壳聚糖作为载体进行金属鏊合亲和层析(IMAC)分离纯化的大蒜SOD,检测其酶活性质和SOD的所属种类,用电泳分析其性质及分子量。结果:从丙酮沉淀法能较快地从大蒜汁中分离到粗品SOD,经过金属鏊合层析纯化的SOD活性达到4206 u/mg,属Cu/Zn-SOD种,分子量27750。     

叶酸偶联华蟾素壳聚糖纳米粒的制备及其特性研究

目的:制备叶酸偶联壳聚糖载华蟾素纳米粒,并检测其体外性质。方法:首先合成叶酸偶联壳聚糖,再制备负载华蟾素的叶酸偶联壳聚糖纳米粒,并测定叶酸偶联华蟾素壳聚糖纳米粒的载药量、包封率及累积释药量。结果:制备了叶酸偶联华蟾素壳聚糖纳米粒,载药量为9.7%,包封率为61.3%,12h累积释药量为42.6%,72h累积释药量为63.3%。结论:叶酸偶联华蟾素壳聚糖纳米粒制备工艺简单,性能较好。     

苦瓜化学成分及药理作用研究进展＊

苦瓜是一种常见的药食两用中药，具有很好的营养及药用价值。苦瓜含有生物碱、皂苷、多肽、维生素和矿物质等多种生物活性化合物，可为人体提供基本营养素、预防及治疗各种疾病。现代研究发现苦瓜除了在传统中药理论中有良好的清热解毒效果外，也能治疗多种癌症、糖尿病、腹痛、肾脏结石、发烧和疥疮等，也可作为药膳辅助疾病的治疗，而且临床不良反应少，用药更为安全。研究证实，苦瓜降糖多肽结构类似于胰岛素，具有良好的降血糖作用；苦瓜中提取的齐墩果烷和葫芦烷型三萜类物质具有抗肿瘤活性、抗微生物活性、抗血小板凝聚作用等。本文重点综述了苦瓜的化学成分及药理作用研究进展，以期为苦瓜的深入研究提供参考。     

Momordica charantia extract on insulin resistance and the skeletal muscle GLUT4 protein in fructose-fed rats

Aim of the study

We investigated the preventive effect of Momordica charantia Linn. (Cucurbitaceae) fruit, commonly known as bitter melon, on hyperglycemia and insulin resistance in rats fed with a fructose-enriched diet.

Materials and methods

First, rats were divided randomly into two groups: the control group was fed with control diet, whereas the experimental group was fed with a 60% high-fructose diet for 8 weeks. After the first 6 weeks, the fructose-treated rats were further subdivided into six groups and were orally fed with or without Momordica charantia L. or rosiglitazone (ROS) for 2 weeks while rats were still on fructose diet.

Results

We demonstrated that bitter melon was effective in ameliorating the fructose diet-induced hyperglycemia, hyperleptinemia, hyperinsulinemia, and hypertriglyceridemia as well as in decreasing the levels of free fatty acid (FFA) (P < 0.001, P < 0.05, P < 0.05, P < 0.05, P < 0.05, respectively). Bitter melon reversed fructose diet-induced hypoadiponectinemia (P < 0.05), which provides a therapeutic advantage to insulin resistance in improving insulin sensitivity. Additionally, bitter melon decreased the weights of epididymal (P < 0.05) and retroperitoneal white adipose tissue (WAT) (P < 0.05). Bitter melon increased the expression of peroxisome proliferator-activated receptor γ (PPARγ) in white adipose tissue (WAT). Conversely, bitter melon decreased the expression of leptin in WAT. Furthermore, we demonstrate that bitter melon significantly increases the mRNA expression and protein of glucose transporter 4 (GLUT4) in skeletal muscle.

Conclusions

This study demonstrates, for the first time, the beneficial effects of two different extracts of bitter melon on insulin resistance in rats fed a high-fructose diet thereby producing evidence of the role of changes in expression of PPARγ and GLUT4.     

Bitter melon fruit extract has a hypoglycemic effect and reduces hepatic lipid accumulation in ob/ob mice

Bitter melon (Momordica charantia L.) is a vegetable and has been used as traditional medicine. Recently, we reported that bitter melon fruit extracts and its ethyl acetate (EtOAc)‐soluble fraction markedly suppressed the expression of proinflammatory genes, including the inducible nitric oxide synthase gene. However, it is unclear whether bitter melon exhibits antidiabetic effects. In this study, we showed that cucurbitacin B, a cucurbitane‐type triterpenoid, was present in an EtOAc‐soluble fraction and suppressed nitric oxide production in hepatocytes. When the EtOAc‐soluble fraction was administered for 7 days to ob/ob mice, a type 2 diabetes mellitus model, the mice fed with this fraction exhibited a significant decrease in body weight and blood glucose concentrations compared with the mice fed without the fraction. The administration of the fraction resulted in significant increases in serum insulin concentrations and the levels of both insulin receptor mRNA and protein in the ob/ob mouse liver. The EtOAc‐soluble fraction decreased the interleukin‐1β mRNA expression, as well as hepatic lipid accumulation in hepatocytes. Taken together, these results indicate that administration of an EtOAc‐soluble fraction improved hyperglycemia and hepatic steatosis, suggesting that this fraction may be responsible for both the antidiabetic and anti‐inflammatory effects of bitter melon fruit.     

Effects of Momordica charantia powder on serum glucose levels and various lipid parameters in rats fed with cholesterol-free and cholesterol-enriched diets

The effects of dietary bitter melon (Momordica charantia) freeze-dried powder on serum glucose level and lipid parameters of the serum and liver were studied in rats fed diets supplemented with and without cholesterol. Rats were fed the diets for 14 days containing bitter melon freeze-dried powder at the level of 0.5, 1 and 3% without an added dietary cholesterol (experiment I) and those containing bitter melon at the level of 1% with or without 0.5% cholesterol and 0.15% bile acid (experiment II). No adverse effect of dietary bitter melon powder on growth parameters and relative liver weight were noted. Dietary bitter melon resulted in a consistent decrease in serum glucose levels in rats fed cholesterol-free diets, but not in those fed cholesterol-enriched diets, although no dose-response was noted. Addition of cholesterol to the diets as compared to those without added cholesterol caused hypercholesterolemia and fatty liver. Bitter melon had little effect on serum lipid parameters, except for high density lipoprotein (HDL)-cholesterol; HDL-cholesterol levels tended to decrease by dietary cholesterol, while they were consistently elevated by dietary bitter melon both in the presence and absence of dietary cholesterol, indicating an antiatherogenic activity of bitter melon. In addition, bitter melon exhibited a marked reduction in the hepatic total cholesterol and triglyceride levels both in the presence and absence of dietary cholesterol; the reduction of triglyceride levels in the absence of dietary cholesterol was in a dose-dependent manner. These results suggest that bitter melon can be used as a health food.     

Metabolomics Reveals that Momordica charantia Attenuates Metabolic Changes in Experimental Obesity

Momordica charantia L., also known as bitter melon, has been shown to ameliorate obesity and insulin resistance. However, metabolic changes regulated by M. charantia in obesity are not clearly understood. In this study, serums obtained from obese and M. charantia‐treated mice were analyzed by using gas and liquid chromatography‐mass spectrometry, and multivariate statistical analysis was performed by Orthogonal partial least squares discriminant analysis. The results from this study indicated that body weight fat and insulin levels of obese mice are dramatically suppressed by 8 weeks of dietary supplementation of M. charantia. Metabolomic data revealed that overproductions of energy and nutrient metabolism in obese mice were restored by M. charantia treatment. The antiinflammatory and inhibition of insulin resistance effect of M. charantia in obesity was illustrated with the restoration of free fatty acids and eicosanoids. The findings achieved in this study further strengthen the therapeutic value of using M. charantia to treat obesity. Copyright © 2016 John Wiley & Sons, Ltd.     

The effects of bitter melon (Momordica charantia) on serum and liver triglyceride levels in rats

Effects of three different varieties (Koimidori, Powerful-Reishi, and Hyakunari) of bitter melon (Momordica charantia) and those of methanol fraction extract of Koimidori variety on serum and liver triglycerides were studied in rats. Feeding of diets containing either bitter melon or various fractions isolated by organic solvents caused no adverse effects on food intake or growth of rats. When the effect of three different varieties of bitter melon was compared, the Koimidori variety was found to be the most effective in lowering hepatic triglyceride levels as compared to the other two varieties, suggesting a variety-dependent difference in their activity. Furthermore, the active component(s) responsible for the liver triglyceride lowering activity of Koimidori variety was assumed to be concentrated in the methanol fraction, but not in other fractions such as the n-hexane, the acetone, or the residual fraction. The triglyceride lowering activity was furthermore confirmed by the dose-dependent reduction of hepatic triglyceride, resulting the lowest level in rats fed 3.0% supplementation. In these experiments, the effects on serum lipids were marginal. The results of the present and previous studies clearly show that bitter melon, especially Koimidori variety, exhibits a potent liver triglyceride-lowering activity.     

海胆壳蛋白的分离纯化及抗肿瘤活性

目的：从光棘球海胆（Strongylocentrotus nudus）中分离纯化具有生物活性的海胆壳蛋白。方法：海胆壳先经丙酮脱脂，然后生理盐水提取、超滤、离心得海胆壳蛋白粗品。粗品经超滤、DEAE—Sepharose Fast Flow及Sephacryl S-400柱层析纯化得海胆壳蛋白SUP-1A。经聚丙烯酰胺凝胶电泳和高效液相色谱鉴定其纯度达90％以上。通过MTT法测定了SUP-1A的体外抗肿瘤活性。结果：从海胆壳中分离纯化得到单一蛋白组分的SUP-1A，MTT法表明SUP-1A对多种肿瘤细胞的增殖都有较强的抑制作用。结论：从海胆壳中分离纯化到一种蛋白组分SUP-1A，其具有较强的体外抗肿瘤活性。     

苦瓜提取物抑制蛋白质的非酶糖基化

目的:研究苦瓜提取物对蛋白质非酶糖基化终末产物( AGE)生成的抑制作用.方法:体外蛋白质非酶糖基化反应系统中分别加入不同质量浓度的苦瓜提取物(0.01,0.1,1.0 g·L-1)或氮基胍(4 mmol·L-1),在不同时间分别测定蛋白质非酶糖化终末产物的生成量.制备糖尿病小鼠模型,以苦瓜提取物10,30 g·kg-1两个剂量连续ig 14 d,测定苦瓜提取物对糖尿病小鼠血糖以及心、肝、肾组织中AGE含量、超氧化物歧化酶(SOD)活性和丙二醛(MDA)含量的影响.结果:在体外系统中,蛋白糖化产物的生成与孵育时间呈正相关,苦瓜提取物浓度依赖性抑制蛋白糖化终末产物的生成(P＜0.01).动物实验表明苦瓜提取物能抑制血糖升高(P ＜0.05,P＜0.01),改善糖尿病小鼠心、肝、肾组织中AGE含量(P ＜0.05,P＜0.01)、升高SOD活性(P ＜0.05,P＜0.01)和降低MDA含量(P＜0.05,P＜0.01),呈现剂量效果正相关.结论:苦瓜提取物体内体外均可有效抑制蛋白糖化终末产物的生成.     

寡糖分离纯化和鉴定方法的研究进展

寡糖作为近年来备受关注的中药活性成分之一，具有广泛的药理活性和开发应用前景。寡糖种类多样、组成复杂，存在多种异构体，分离纯化和结构鉴定存在较大难度。采用文献分析法，系统梳理了近20年有关寡糖研究的相关文献，归纳了寡糖分离纯化的主要方法，包括色谱法（凝胶色谱法、离子交换色谱法、反相高效液相色谱法、活性炭色谱法、石墨化碳色谱法、亲水作用色谱法）、毛细管电泳法、膜分离技术等，以及寡糖结构鉴定的主要方法，包括紫外光谱法、红外光谱法、核磁共振波谱法、质谱法、色谱法、色谱-质谱联用技术等，并分析了这些方法的适用范围和发展趋势。     

刺异叶花椒香豆素类化学成分

目的 :对刺异叶花椒Zanthoxylumdimorphophyllum化学成分进行研究 ,分离并鉴定化合物。 方法 :采用现代色谱分离技术进行化学成分的分离 ,运用光谱方法确定所分离化合物的结构。结果 :从中分离得到 4个化合物 ,分别为美花椒内酯 (I) ,异茴芹内酯 (Ⅱ) ,6 (3′-甲基-2′,3′-丁二醇基 )-7-羟基 香豆素 (Ⅲ ) ,6-(3′-甲基-2′-O-β-D-吡喃葡萄糖基 3′-羟基 丁基 )7-羟基 香豆素 (Ⅳ )。 结论 :以上化合物均为首次从该植物中分得。