知母水溶性小分子提取物对胰岛素抵抗HepG2细胞体外糖代谢的影响

目的 研究知母水溶性小分子提取物的制备及其对胰岛素抵抗HepG2 (IR-HepG2)细胞糖代谢的作用.方法 采用水提取,膜分离方式制备知母提取物;采用高浓度胰岛素持续作用于HepG2细胞24 h建立胰岛素抵抗模型,加入知母水溶性小分子提取物保温24 h后,测定对照组和加药组细胞内葡萄糖消耗量、肝糖原含量及己糖激酶(hexokinase,HK)、丙酮酸激酶(pyruvate kinase,PK)的活性.结果 知母水溶性小分子提取物明显增加细胞的葡萄糖消耗、提高IR-HepG2细胞HK、PK活性,增加肝糖原含量.结论 知母水溶性小分子提取物可明显改善胰岛素抵抗状态下HepG2细胞对葡萄糖的利用,提高肝HK、PK活性,促进葡萄糖进入肝细胞,增加肝糖原合成,促进糖代谢.     

高粱根提取物体外抗氧化活性评价

采用水杨酸显色法、DPPH·法、铁氰化钾显色法对高粱根提取物进行抗氧化活性评价,得出了高粱根75%乙醇粗提物、75%乙醇提取正丁醇萃取物、水提粗提物和水提后60%乙醇沉淀的上清部位样品的抗氧化作用结果,并以Vc作为阳性对照。实验结果显示:高粱根的水提物的抗氧化活性明显优于醇提物,尤其是水提醇沉上清部位,此部位对·OH的清除作用与Vc相当,在质量浓度为(0.5~1.5)mg/m L时其清除率略高于Vc,在对DPPH·的清除测定中水提醇沉上清部位的清除率也明显高于其他部位;在对Fe~(3+)的还原测定中,此部位的还原能力也较其他部位强。3种测定方法综合结果表明,在高粱根提取物中,水提物的抗氧化活性要比醇提物的效果好。     

列当不同提取物降糖作用研究

目的研究列当不同提取物的降糖作用。方法本试验提取列当多糖、醇提物及水提物,应用四氧嘧啶建立小鼠糖尿病模型,并对列当提取物的降血糖作用进行综合评价。结果多糖和醇提物的低剂量、水提物中剂量均可显著降低小鼠的血糖值(P0.05)。其中醇提物低剂量组效果明显,对糖尿病具有一定的预防及治疗作用。多糖低剂量、醇提物和水提物的高剂量对体重的作用比较明显,其中水多糖低剂量组对糖尿病小鼠的体重有明显的提高。多糖3个剂量和醇提物中剂量、水提物高剂量组显著降低小鼠血脂(P0.05)。结论列当不同提取物多糖、水提物、醇提物具有明显的降血糖作用。     

杨梅疏果核仁苦杏仁苷提取物的生物活性研究

为了研究杨梅疏果核仁苦杏仁苷提取物的生物活性,采用DPPH和ABTS抗氧化体系,考察其粗提物和精提物的抗氧化活性,并通过小鼠止咳祛痰试验研究提取物的止咳祛痰功效。研究发现杨梅疏果核仁提取物对DPPH自由基和ABTS自由基具有良好的清除效果,且提取物浓度与清除率表现出较好的相关性。分析并计算得到粗提物与精提物清除DPPH自由基的IC_(50)值分别为1 335 mg/L和261 mg/L,清除ABTS自由基的IC50值分别为1 447 mg/L和281 mg/L,杨梅疏果核仁苦杏仁苷精提物较粗提物表现出了更好的体外抗氧化活性。通过ICR小鼠止咳祛痰功能试验发现杨梅疏果核仁苦杏仁苷粗提物45,90,180 mg/kg各剂量均能不同程度地延长氨水引咳小鼠的咳嗽潜伏期,减少2 min内的咳嗽次数,其中90 mg/kg剂量组咳嗽潜伏期较对照组明显延长(P0.05),表明其有较好的止咳功效。杨梅疏果核仁苦杏仁苷粗提物各剂量组以及苦杏仁苷标准品对小鼠气管酚红排泌量影响不显著,表明无明显祛痰作用。     

桔梗乙醇提取物的抑菌活性研究

对桔梗95%乙醇提取物做体外抑菌试验,测试该提取物对受试菌的最低抑菌浓度,考察温度、pH、紫外照射时间对抑菌活性的影响,运用系统预试验分析醇提物的化学成分。在7种受试菌中,桔梗醇提物对变形杆菌的抑制作用最强,大肠杆菌次之,两者的最低抑菌浓度均为125 mg/m L。桔梗乙醇提取物对细菌的抑菌作用要强于真菌,而对革兰氏阴性菌的抑菌效果强于革兰氏阳性菌。醇提物对温度和紫外光具有良好的稳定性,pH在4~6时,有良好的抑菌作用。预试验表明桔梗醇提物的活性成分可能有皂苷、三萜类、多酚、黄酮等。     

水生蔬菜提取物的抗氧化活性分析及其对菜籽油的抗氧化作用

研究七种常见水生蔬菜不同部位提取物的抗氧化活性以及对油脂抗氧化的效果。采用ABTS自由基清除法、DPPH自由基清除法检测菱角、芡实、莲藕、水芋头、茭白、荸荠和慈姑不同部位的醇提物、水提物的抗氧化活性,烘箱法测定对菜籽油过氧化值的影响。在30种提取物中DPPH自由基清除能力较强的三种提取物IC50值分别为:芡实壳醇提物(0.03 mg/mL)芡实壳水提物(0.04mg/m L)=菱角壳醇提物(0.04mg/m L);ABTS自由基清除能力较强的三种提取物Trolox含量分别为芡实壳醇提物(1.42g/g)芡实壳水提物(1.41 g/g)菱角壳醇提物(1.15 g/g);添加0.1%浓度的五种提取物第7 d的POV值分别为23.86 meq/kg、24.06 meq/kg、23.53meq/kg、24.43 meq/kg、22.40 meq/kg,五种提取物的油脂抗氧化效果均不如0.1%浓度的BHA。30种水生蔬菜提取物中,芡实壳和菱角壳的醇提物、水提物DPPH自由基清除能力最强,芡实壳醇提物、水提物ABTS自由基清除能力最强;芡实壳水提物、芡实壳醇提物、菱角壳水提物、菱角壳醇提物以及藕节醇提物对菜籽油有一定抗氧化的效果,但效果弱于相同剂量的BHA。     

普洱茶醇提不同萃取物的体外抑菌活性研究

采用滤纸片扩散法研究了普洱茶95%醇提萃取物石油醚、氯仿、乙酸乙酯、正丁醇和萃取后剩余物对金黄色葡萄球菌(S.aureus)和大肠杆菌(E.coli)的体外抑菌效果及普洱茶醇提乙酸乙酯萃取物抑菌活性的稳定性.结果表明:上述4种普洱茶醇提萃取物对S.aureus和E.coli均有一定的抑制作用,其中,乙酸乙酯萃取物的抑菌效果最好,对两种受试菌抑菌圈直径分别为(31.88±0.24)mm和(22.81±0.31)mm,最小抑菌浓度MIC分别为0.47 mg/m L和0.35 mg/m L.乙酸乙酯萃取物稳定性实验结果表明:普洱茶醇提乙酸乙酯萃取物在不同温度和紫外光照条件下均具有良好的抑菌稳定性,但酸碱性对其抑菌活性影响明显,抑菌效果随p H值的增大而逐渐变差.     

普洱茶不同提取物体外抑菌活性研究

研究了不同溶剂普洱茶提取物及萃取物的体外抑菌活性。论文采用滤纸片扩散法和最低抑菌浓度检测了水提、75%和95%乙醇普洱茶提取物对S.aureus、E.coli、P.aeruginosa及B.subtilis体外抑菌效果。同时分析了95%醇提物的不同溶剂萃取物对供试菌的影响。结果表明:95%乙醇浸提物抑菌效果最好,尤其对S.aureus、E.coli最为明显,抑菌圈分别为19.58±0.24 mm、14.58±0.24 mm,MIC分别为0.63 mg/mL,0.39 mg/mL,但对B.subtilis抑菌效果差。在95%醇提物的不同溶剂萃取物中,萃取物抑菌活性为:乙酸乙酯>正丁醇>石油醚>氯仿。乙酸乙酯萃取物对S.aureus抑制效果最好,其抑菌圈直径为31.88±0.24 mm,MIC为0.47 mg/mL。普洱茶提取物的醇提乙酸乙酯萃取提物能显著抑制革兰氏阴性菌和阳性菌的生长,研究结果为普洱茶抗菌活性成分的开发利用提供一定的实践和数据参考。     

老山芹不同溶剂提取物的活性成分及其促进细胞生长活性

为研究老山芹不同溶剂提取物的活性功能,本研究老山芹为原料,比较了不同溶剂提取物的活性成分和抗氧化效果,以及不同溶剂提取物对α-葡萄糖苷酶和α-淀粉酶的影响,并对适宜条件下不同溶剂提取物对HepG2和panc-1细胞的影响进行研究。试验结果表明:随着浓度的增加两种酶抑制率而不断增大,并得出两种酶抑制率的IC50值,碱提取条件下α-葡萄糖苷酶和α-淀粉酶的IC50最小,分别为0.47 mg/mL、2.17 mg/mL。四种溶剂提取物中多糖含量最高的是碱提取,含量为58.09 mg/g;总酚含量最高的是醇提物,含量为11.48 mg/g;黄酮含量最高的是醇提物,含量为3.96 mg/g,并且四种提取物中醇提物的抗氧化活性最高,酸提物抗氧化活性最低。四种溶剂提取物在低浓度条件下,均能促进HepG2和panc-1细胞的增长,随着浓度的增加HepG2和panc-1细胞存活率均呈不同程度的下降,提取物在高浓度条件下对细胞有抑制作用。     

水生蔬菜提取物抑制人肝癌HepG2细胞和人胃癌SGC7901细胞的增殖

为探究水生蔬菜不同部位提取物对人肝癌HepG2细胞和人胃癌SGC7901细胞增殖的影响。本研究对菱角、芡实、莲藕、水芋头、茭白、荸荠和慈姑等7种常见的水生蔬菜的不同部位进行醇提和水提获得15种醇提物、15种水提物。采用CCK-8法检测不同提取物对人肝癌HepG2、人胃癌SGC7901细胞增殖的影响。结果表明菱角壳醇提物、芡实壳醇提物及水提物对HepG2的增殖具有明显的抑制作用及剂量效应,其浓度在400 μg/mL时抑制率分别为70.20%、83.52%、71.89%,相同浓度下阳性药五氟尿嘧啶（5-Fu）的抑制率为73.19%。菱角壳醇提物及水提物、芡实壳醇提物与水提物、芡实肉醇提物、藕节醇提物和荸荠皮醇提物对SGC7901的增殖有较好的抑制作用及剂量效应,其浓度在400 μg/mL时抑制率分别为58.86%、46.79%、41.27%、67.11%、49.93%、57.3%、58.96%,相同浓度下阳性药五氟尿嘧啶（5-Fu）的抑制率为49.33%。Pearson相关性分析表明水生蔬菜提取物对肿瘤细胞增殖的影响与其黄酮、多酚的含量有关。     

Prenylated chalcones 4-hydroxyderricin and xanthoangelol stimulate glucose uptake in skeletal muscle cells by inducing GLUT4 translocation

Scope: Glucose uptake in skeletal muscle is crucial for glucose homeostasis. Methods and results: Insulin and muscle contraction increase glucose uptake accompanied by the translocation of glucose transporter (GLUT) 4. In a search for promising foods, which can increase glucose uptake in skeletal muscle, we screened for active polyphenols by assaying for uptake of 2‐deoxyglucose (2DG) in rat L6 muscle cells. Among 37 compounds, 4‐hydroxyderricin and xanthoangelol, prenylated chalcones abundant in Ashitaba (Angelica keiskei Koidzumi, family Apiaceae), significantly increased 2DG uptake in L6 cells by 1.9‐fold at 10 μM, compared with the level in DMSO‐treated control cells. Next, we investigated the effect of these chalcones on the translocation of GLUT4 and its underlying mechanisms. The chalcones increased the GLUT4 level in the plasma membrane of L6 cells, but activated neither protein kinase C ζ/λ, Akt, nor adenosine monophosphate‐activated protein kinase, all of which regulate the GLUT4 translocation. Interestingly, the oral administration of a titrated chalcone‐enriched Ashitaba extract containing 150.6 mg/g (dry base) of 4‐hydroxyderricin and 146.0 mg/g (dry base) of xanthoangelol suppressed acute hyperglycemia in oral glucose tolerance tests of mice. Conclusions: Ashitaba is a promising functional food for the maintenance of the blood glucose level by inducing skeletal muscle‐associated glucose uptake.     

Evaluation of Different Mexican Plant Extracts to Control Anthracnose

The fungal plant infection caused by Colletotrichum gloeosporioides known as anthracnose, affects tropical fruits thus causing low yield and poor fruit quality. The antifungal activity of ethanol and chloroform extracts of different Mexican plants jarilla (Baccharis salicifolia), tepozan (Buddleia americana), nanche (Byrsonima cordata), cinco negritos (Lantana camara), Mexican oregano (Lippia berlandieri var. Scanner), and pericon (Tagetes lucida) against C. gloeosporioides were evaluated by determining the minimum inhibitory concentration (MIC) of the ethanol and chloroform extracts. Subsequently, an antifungal assay was carried out by determining the inhibition of radial growth in PDA plates added with plant extracts. Jarilla, oregano, and pericon MIC values were 400 mg/L for ethanol extracts and 200 mg/L for chloroform extracts. Tepozan, nanche, and cinco negritos showed no antifungal effect. Concerning the inhibition of radial growth, pericon ethanol extract showed an 84% inhibition; chloroform extracts of jarilla, oregano, and pericon showed 88%, 90%, and 95% inhibition, respectively. The ethanol extracts of oregano and jarilla demonstrated to be inhibitory at the reproductive phase of C. gloeosporioides, while their chloroform extracts have a fungistatic effect.     

Anti-diabetic potential of a Sasa quelpaertensis Nakai extract in L6 skeletal muscle cells

The anti-diabetic potential of a Sasa quelpaertensis Nakai extract (SQE) in L6 muscle cells was evaluated. The SQE stimulated glucose uptake via the AMP-activated protein kinase-activating pathway, but not via the insulinstimulating pathway. The SQE increased the expression of fatty acid translocase and peroxisome proliferator-activated receptor γ, and induced phosphorylation of acetyl-CoA carboxylase. The SQE attenuated oleic acid-induced intracellular triglyceride contents by decreasing the expression of sterol regulatory element-binding protein-1c and fatty acid synthase. These results indicate that the SQE probably has an anti-diabetic potential by enhancing glucose uptake and reducing triglyceride content in L6 skeletal muscle cells.     

山奈抗氧化活性部位研究

为筛选具有较优抗氧化活性的山奈抗氧化活性部位,采用80%乙醇溶液超声提取山奈,提取物依次用石油醚、氯仿、乙酸乙酯和正丁醇萃取,制备了山奈乙醇提取物和石油醚相、氯仿相、乙酸乙酯相、正丁醇相和水余相5个部位,并分别采用DPPH和ABTS法测试了其抗氧化活性。结果显示:山奈提取物具有较好的抗氧化活性,5个部位中,氯仿相抗氧化活性最好,其对ABTS的半清除浓度约为阳性对照V_C的2倍,对DPPH的半清除浓度约为阳性对照V_C的4倍,乙酸乙酯相也具有较好的抗氧化活性,再次是正丁醇相,石油醚相抗氧化活性较差,水余相基本没有抗氧化活性。山奈具有较好的抗氧化活性,抗氧化活性成分主要集中在氯仿相和乙酸乙酯相。     

Saffron (Crocus sativus L.) increases glucose uptake and insulin sensitivity in muscle cells via multipathway mechanisms

Saffron (Crocus sativus Linn.) has been an important subject of research in the past two decades because of its various biological properties, including anti-cancer, anti-inflammatory, and anti-atherosclerotic activities. On the other hand, the molecular bases of its actions have been scarcely understood. Here, we elucidated the mechanism of the hypoglycemic actions of saffron through investigating its signaling pathways associated with glucose metabolism in C₂C₁₂ skeletal muscle cells. Saffron strongly enhanced glucose uptake and the phosphorylation of AMPK (AMP-activated protein kinase)/ACC (acetyl-CoA carboxylase) and MAPKs (mitogen-activated protein kinases), but not PI 3-kinase (Phosphatidylinositol 3-kinase)/Akt. Interestingly, the co-treatment of saffron and insulin further improved the insulin sensitivity via both insulin-independent (AMPK/ACC and MAPKs) and insulin-dependent (PI 3-kinase/Akt and mTOR) pathways. It also suggested that there is a crosstalk between the two signaling pathways of glucose metabolism in skeletal muscle cells. These results could be confirmed from the findings of GLUT4 translocation. Taken together, AMPK plays a major role in the effects of saffron on glucose uptake and insulin sensitivity in skeletal muscle cells. Our study provides important insights for the possible mechanism of action of saffron and its potential as a therapeutic agent in diabetic patients.     

Potential role of adenosine monophosphate-activated protein kinase in regulation of energy metabolism in dairy goat mammary epithelial cells

The 5′-adenosine monophosphate-activated protein kinase (AMPK) is an energy sensor that regulates cellular metabolism. 5′-Adenosine monophosphate-activated protein kinase controls glucose and lipid metabolism in skeletal muscle, liver, and adipose tissues. The aim of this study was to investigate the effects of AMPK on glucose and lipid metabolism in dairy goat mammary epithelial cells. Treatment of mammary epithelial cells with an AMPK activator (5-aminoimidazole-4-carboxamide 1-β-d-ribofuranoside) dramatically increased glucose uptake and glucose transporter-1 mRNA abundance, and decreased levels of glycogen synthase 1 mRNA. Activation of AMPK also induced an increase in carnitine palmitoyl transferase 1 mRNA and decreases in fatty acid synthase and acetyl-CoA carboxylase 1 mRNA. These results suggest that AMPK is involved in the regulation of energy metabolism in dairy goat mammary epithelial cells.     

Continuous Potable Alcohol Production by Immobilized Zymomonas mobilis on γ-Alumina Pellets

Experiments were carried out with Z. mobilis immobilized on -γ-alumina pellets in a continuous reactor for potable alcohol production. It was found that -γ-alumina was a suitable support for continuous ethanol production processes. Specifically, an ethanol productivity (calculated on the basis of liquid volume) of 23.8 g/L/hr was achieved at 0.88 hr^?1dilution rate, 159 g/L invert sugar content and 43.7% conversion, using raisin extracts as feed material. Similar productivities were obtained with media containing glucose. Biomass productivity, yield and free cells concentration in glucose and raisin extracts were examined. Ethanol production was constant during the time the system was operated, a period of over 60 days.     

Hibiscus sabdariffa L. extracts inhibit the mutagenicity in microsuspension assay and the proliferation of HeLa cells

ABSTRACT:  Hibiscus sabdariffa L. is used as a refreshing beverage and as a traditional medicine. The objective of this study was to determine the in vitro effect of phenolic compounds present in aqueous, ethyl acetate, and chloroform extracts of H. sabdariffa against mutagenicity of 1-nitropyrene (1-NP), and also the antiproliferative effect of these extracts. Inhibition of cell proliferation and DNA fragmentation were tested on transformed human HeLa cells. The hot aqueous extract (HAE) contained 22.27 ± 2.52 mg of protocatechuic acid (PCA) per gram of lyophilized dried extract, and was not statistically different from the cold aqueous or chloroform extracts; the ethyl acetate extract produced the least amount of PCA. The H. sabdariffa extracts inhibited mutagenicity of 1-NP in a dose-response manner. The inhibition rate on HeLa cells of HAE was also dose-dependent. The HAE did not induce DNA fragmentation. The results suggest that H. sabdariffa L. extracts have antimutagenic activity against 1-NP and decrease the proliferation of HeLa cells, probably due to phenolic acid composition.     

Catechins enhance skeletal muscle performance

Abstract

Muscle-related disorders, such as sarcopenia and cachexia, caused by aging and chronic diseases can lead to the loss of muscle mass and strength to different degrees, severely affecting human health. Globally, tea is one of the three most popular beverages, and its major active ingredient catechins have been reported to delay muscular atrophy and enhance movement. However, currently, there is no systematic review to elaborate its roles and the associated mechanisms. This article reviews the (1) functions and mechanisms of catechins in the differentiation of myogenic stem cells, biogenesis of mitochondria, synthesis and degradation of proteins, regulation of glucose level, and metabolism of lipids in muscle cells; and (2) effect of catechins on the blood vessels, bones, and nerves that are closely related to the skeletal muscles. Catechins could prevent, mitigate, delay, and even treat muscle-related disorders caused by aging and diseases.     

Antioxidant effect rosemary (Rosmarinus officinalis L.) and oregano (Origanum vulgare L.) extracts on TBARS and colour of model raw pork batters

Herbs and spices are traditional used as food ingredients as well as for their antioxidant properties. The objective of this work was to study the concentration of carnosol, rosmarinic and carnosic acids in rosemary (Rosmarinus officinalis L.) and oregano leaves (Origanum vulgare L.), and their effect on the oxidation and colour of model pork batters. Extracts were obtained by maceration with ethanol and reflux with chloroform. Rosemary extracts showed higher antioxidant activity, even more than the phenol compounds separately. These extracts also showed the highest antioxidant capacity, possibly due to the presence of high concentrations of carnosic acid and carnosol and unidentified active compounds. However, ethanol oregano extracts containing high concentrations of phenols, mainly rosmarinic acid, efficiently prevented colour deterioration. The antioxidant effect of the studied extracts depends, not only on the concentration of phenol compounds (rosmarinic acid, carnosol and carnosic acid), but also on the extraction method and solvent.