共查询到19条相似文献,搜索用时 31 毫秒
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建立HPLC-ELSD法,测定三种植物基原金线莲中金线莲苷含量。采用phenomenex NH2色谱柱(250 mm×4.6 mm,5μm),以乙腈-水(92∶8,V/V)为流动相进行等度洗脱,流速为0.8 m L/min,柱温室温,ELSD雾化室温度为70℃,氮气流速为1.5 L/min。实验结果表明,金线莲苷进样量在76.022432.64μg/m L范围内线性良好(r=0.9991);精密度、稳定性、重复性实验的RSD均≤3%;平均加样回收率为97.55%,RSD为1.50%(n=6)。33批次金线莲的金线莲苷含量在6.37%22.66%之间,平均含量为15.00%,存在较大的差异(RSD=26.29%)。该方法快速、简便,结果准确、可靠,适用于金线莲中金线莲苷的定量分析。 相似文献
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为进一步提高金线莲苷的分离纯化效率,该研究以深度共熔溶剂提取的金线莲苷粗品为基础,比较了大孔树脂法和硅胶柱层析法分离金线莲苷的效果,并优化了硅胶柱层析法分离金线莲苷的条件。实验结果表明,DM130型大孔树脂对金线莲苷的吸附量仅为24.69 mg/g,解吸率为17.89%,且无法选择性的分离金线莲苷,而硅胶柱层析法对金线莲苷的分离效果较好;硅胶柱层析法分离金线莲苷的最佳条件为:洗脱溶剂为乙酸乙酯:乙醇:乙酸=6:4:0.2(V/V/V),上样量为0.60 g,洗脱速率为1.25 mL/min,在此条件下,金线莲苷的回收率可达79.29%;硅胶柱层析分离组分经半制备型高效液相色谱纯化所得的金线莲苷纯度大于99.00%。该研究建立了一种简单高效的金线莲苷分离纯化流程,有利于金线莲产业的发展,为后续的研究工作提供理论支持。 相似文献
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探究蓝莓花色苷提取物对胰岛素抵抗的人肝癌细胞HepG2细胞对葡萄糖消耗的干预作用。利用MTT实验筛选得到3个品种蓝莓花色苷提取物的最适作用浓度;筛选胰岛素和葡萄糖诱导HepG2细胞产生胰岛素抵抗的最佳浓度;以MTT矫正细胞数量,用葡萄糖氧化酶法检测细胞培养基中葡萄糖的变化来研究蓝莓花色苷提取物的对细胞胰岛素抵抗的干预作用。北陆花色苷提取物在低于200μg/m L的浓度时,灿烂和园蓝花色苷提取物在低于100μg/m L的浓度时,对HepG2细胞活力无明显影响;以诱导剂胰岛素的浓度为1×10-8mol/L,孵育24h作为诱导条件,其模型效果较佳、对细胞活力改变小且稳定性好;3个品种的蓝莓花色苷提取物在7.8125~31.25μg/m L浓度时,可不同程度促进正常HepG2细胞和胰岛素抵抗的HepG2细胞对葡萄糖的消耗量,且与剂量成正比关系,在31.25μg/m L达到促进最大值,与模型组比较均有极显著差异,糖消耗量分别增加了60%、65%和88%。三个品种的蓝莓花色苷提取物均能较好的预防和改善胰岛素抵抗HepG2细胞对葡萄糖的利用。 相似文献
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苦荞是芦丁含量最高的粮食作物,但不同的加工过程会导致芦丁降解为单糖苷结构的异槲皮素及其前体槲皮素,进而影响生物活性。本研究比较芦丁及其降解产物(槲皮素、异槲皮素)这三类含有不同糖苷结构的黄酮在C2C12小鼠骨骼肌细胞中促进葡萄糖摄取的功效差异,并探究其作用机制。研究结果表明,苦荞与水接触会导致苦荞中的核心黄酮组分-芦丁降解为槲皮素。芦丁及其降解产物(槲皮素、异槲皮素)均能有效促进C2C12细胞对葡萄糖的摄取,作用顺序为:槲皮素>异槲皮素>芦丁。糖苷键的增加会降低槲皮素促进骨骼肌细胞糖摄取的效果。芦丁和异槲皮素不能激活胰岛素依赖型信号通路中的IRS-1表达及AKT的磷酸化,但高浓度下(400 μmol/L),芦丁和异槲皮素可以通过非胰岛素依赖型的信号通路中的p-AMPK/p-ACC促进葡萄糖摄取作用,且异槲皮素的作用大于芦丁。槲皮素虽然抑制了IRS-1的表达及AKT的磷酸化,但槲皮素通过AMPK/ACC的磷酸化显著了促进C2C12细胞对葡萄糖的摄取。本研究揭示芦丁及其降解产物在细胞水平上的降血糖作用及机理的差异,对于充分理解苦荞黄酮降血糖机制提供了科学依据。 相似文献
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目的:观察紫色马铃薯花色苷对HepG2细胞胰岛素抵抗模型糖代谢的作用并对其机制进行初探。方法:以高浓度葡萄糖培养基为诱导因素诱导HepG2细胞建立胰岛素抵抗细胞模型,通过葡萄糖氧化酶法、四唑盐比色实验(MTT)和蛋白质印迹法(Western blot)检测紫色马铃薯花色苷对胰岛素抵抗细胞模型的葡萄糖消耗量、细胞存活率和胰岛素信号通路的蛋白表达的影响。结果:与空白对照组相比,当诱导培养基中葡萄糖浓度为50 mmol/L时吸光度的差值最大,所以选50 mmol/L的葡萄糖培养基来建立胰岛素抵抗细胞模型;花色苷的处理胰岛素抵抗细胞的浓度为40~100 μg/mL时,葡萄糖消耗量可高达19.55 mmol/L显著(p<0.05)高于模型对照组;花色苷浓度为40~100 μg/mL时细胞存活率基本上可以保持在80%,细胞毒性较小;花色苷可以调节因高浓度葡萄糖诱导而导致的IR、IRS-1、IRS-2水平下降的情况,降低p-IRS-1的表达水平,还可以阻止GLUT-2水平的降低。结论:紫色马铃薯花色苷可以改善HepG2细胞胰岛素抵抗模型的胰岛素信号通路抑制的情况,改善胰岛素抵抗模型的糖代谢。 相似文献
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采用高浓度的胰岛素诱导HepG2细胞出现葡萄糖代谢异常,从胰岛素的添加量和作用时间角度探讨建立胰岛素抵抗细胞(HepG2/IR)模型的最佳条件;分别设立阴性对照组、胰岛素抵抗模型组、盐酸吡格列酮阳性对照组以及苦瓜皂苷干预组(100、300、500、700μg/mL),利用葡萄糖测定试剂盒检测各组葡萄糖消耗量,同时MTT法评价苦瓜皂苷对HepG2/IR细胞活性的影响。结果表明,30μg/mL胰岛素诱导处理HepG2细胞36h是产生胰岛素抵抗的最适条件。与HepG2/IR模型组相比,300μg/mL的苦瓜皂苷不仅可以显著改善HepG2/IR细胞的葡萄糖消耗量,还能提高其细胞活性。 相似文献
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由于机体运动能力的降低,与骨骼肌中细胞凋亡之间存在着密不可分的联系,因此深入研究运动与细胞凋亡之间的关系和运动能量引起骨骼肌细胞凋亡的机理意义很大。运动形式与运动强度对骨骼肌细胞凋亡水平有着不可分割的联系,而运动是诱发骨骼肌细胞凋亡的重要遗传的调控。本文主要通过综述运动调节骨骼肌凋亡水平机理,以期为未来探索运动调控骨骼肌凋亡的有效机制,展望运动促进健康研究前景提供理论依据与新思路。 相似文献
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目的:探讨樱桃花色苷(SWCN)的降糖活性,为樱桃高价值深加工与开发提供理论依据。方法:用高脂喂养雄性C57BL/6J小鼠建立肥胖小鼠模型,测定小鼠血清中葡萄糖、胰岛素含量,采用口服葡萄糖耐量实验(OGTT)和胰岛素耐量实验(ITT),评价膳食SWCN对肥胖引起的葡萄糖不耐受和胰岛素抵抗的改善作用。用实时荧光定量PCR检测SWCN对肝脏中糖代谢相关基因的差异表达水平的影响。结果:膳食SWCN能够减缓肥胖的发生,降低肥胖小鼠的血糖、胰岛素水平,减轻胰岛素抵抗和葡萄糖不耐受性。实时荧光定量PCR实验结果表明,膳食SWCN能够提高肥胖小鼠肝脏胰岛素受体底物2(IRS2)的表达水平,同时下调糖异生途径的关键酶磷酸烯醇丙酮酸羧化激酶(PEPCK)和葡萄糖-6-磷酸酶(G6PC)基因的表达水平。结论:膳食樱桃花色苷能够激活肝脏中的胰岛素信号通路,抑制糖异生途径,从而降低肥胖小鼠的空腹血糖及胰岛素含量水平,增强糖耐量和胰岛素敏感性,改善胰岛素抵抗状态。 相似文献
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油橄榄叶不同提取部位对胰岛素抵抗HepG2细胞葡萄糖消耗的影响 总被引:1,自引:0,他引:1
目的:评价油橄榄叶不同提取部位的降糖活性。方法:采用高浓度胰岛素(5.8×10-3mg/mL)诱导培养HepG2细胞24h,建立胰岛素抵抗细胞模型。建模后,培养液中加入各提取部位共同孵育,采用葡萄糖试剂盒法检测24h后培养液中的葡萄糖含量,探讨其对胰岛素抵抗HepG2细胞葡萄糖消耗的影响,并用MTT法检测细胞的增殖水平。结果:油橄榄叶不同提取部位均能增加胰岛素抵抗HepG2细胞的葡萄糖消耗量,部位B、E对模型细胞的增殖起促进作用,部位A、C、D、F对模型细胞的增殖具有抑制作用;结论:经MTT校正后,部位D改善胰岛素抵抗效果最显著。 相似文献
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胰岛素/Akt信号通路受阻所致的骨骼肌细胞蛋白异常分解,可能是骨骼肌萎缩发生的重要原因。不同n-3多不饱和脂肪酸在骨骼肌细胞内、外作用于胰岛素/Akt信号通路上的多个位点,均有助于维持通路的正常运作。其中,植物来源n-3多不饱和脂肪酸ALA能通过活化胰岛β细胞胞膜的GPR40直接促进胰岛素分泌;海鱼来源n-3多不饱和脂肪酸EPA与DHA能有效维持骨骼肌细胞内Akt活性并增加胰岛素敏感性。本文通过对相关文献的归纳总结,阐释n-3多不饱和脂肪酸基于胰岛素/Akt信号通路抑制骨骼肌细胞蛋白异常分解的机制,为通过膳食手段干预骨骼肌萎缩提供新的思路。 相似文献
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Ahyoung Yoo;Jiyun Ahn;Hyo Deok Seo;Jeong-Hoon Hahm;Min Jung Kim;Chang Hwa Jung;Tae Youl Ha; 《Food Science & Nutrition》2024,12(7):5077-5086
Gracilaria chorda (GC) is a red algal species that is primarily consumed in Asia. Here, we investigated the effect of GC on obesity-related skeletal muscle wasting. Furthermore, elucidating its impact on the activation of sirtuin 1 (SIRT1)/peroxisome proliferator-activated receptor gamma coactivator 1α (PGC1α) constituted a critical aspect in understanding the underlying mechanism of action. In this study, 6-week-old male C57BL/6 mice were fed a high-fat diet (HFD) for 8 weeks to induce obesity, then continued on the HFD for another 8 weeks while orally administered GC. GC decreased ectopic fat accumulation in skeletal muscle and increased muscle weight, size, and function in obese mice. Furthermore, GC reduced skeletal muscle atrophy and increased hypertrophy in mice. We hypothesized that the activation of SIRT1/PGC1α by GC regulates skeletal muscle atrophy and hypertrophy. We observed that GC increased the expression of SIRT1 and PGC1α in skeletal muscle of mice and in C2C12 cells, which increased mitochondrial function and biogenesis. In addition, when C2C12 cells were treated with the SIRT1-specific inhibitor EX-527, no changes were observed in the protein levels of SIRT1 and PGC1α in the GC-treated C2C12 cells. Therefore, GC attenuated obesity-related muscle wasting by improving mitochondrial function and biogenesis through the activation of SIRT1/PGC1α in the skeletal muscle of mice. 相似文献
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以1至18月龄乌珠穆沁羊骨骼肌中半腱肌(SD)和股二头肌(BF)为原料,采用组织化学法对肌纤维直径、肌内结缔组织和肌纤维类型的变化进行观察。结果显示,随着月龄的增加,SD和BF中肌纤维直径在1到9月龄之间呈增大趋势,12月龄时显著下降,之后呈上升趋势。SD和BF结缔组织中肌内膜总体呈增厚趋势。肌束膜在1到9月龄呈增厚趋势,到12月龄时有所下降,之后显著上升。随月龄的增加,SD和BF中Ⅰ型肌纤维的变化较大,在9和18月龄时呈下降趋势。SD中Ⅱa型纤维12月龄时百分比最低,而此时Ⅱb型纤维百分比最高。BF中Ⅱa型纤维百分比在1、9、18月龄之间以及3、6月龄之间差异均不显著(p>0.05)。Ⅱb型纤维在18月龄百分比最高。 相似文献
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1 Scope
The renin‐angiotensin system (RAS) is a major contributor to the development of insulin resistance and its related complications. Egg white ovotransferrin‐derived tripeptides, IRW (Ile‐Arg‐Trp), IQW (Ile‐Gln‐Trp), or LKP (Leu‐Lys‐Pro) are previously identified as the inhibitors of angiotensin‐converting enzyme (ACE), a key enzyme in the RAS. This study aims at determining whether these peptides are effective in improving insulin resistance, and their mechanisms of action, in a rat derived skeletal muscle cell line (L6 cells).2 Methods and results
Insulin resistance is induced by treating L6 cells with 1 μm angiotensin II (Ang II) for 24 h. Effects of peptides on glucose uptake are determined using glucose uptake assay, glucose transporter 4 (GLUT4) translocation by immunofluorescence, reactive oxygen species (ROS) by dihydroethidium (DHE) staining, while insulin signaling pathway, Ang II receptor (AT1R or AT2R) levels, and NADPH oxidase activation are measured using Western Blot. Only IRW treatment significantly improves insulin resistance in L6 cells via stimulation of insulin signaling. IRW decreases Ang II‐stimulated AT1R expression, ROS formation, and NADPH oxidase activation.3 Conclusions
Of three ACE inhibitory peptides studied, only IRW improves insulin resistance in L6 cells, at least partially via reduced AT1R expression and its anti‐oxidative activity. 相似文献18.
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Tissue biopsy metabolic activity, assessed using the oxidation-reduction indicator resazurin, may serve as a proxy to assess energy expenditure associated with maintenance in nongrowing animals or growth rate in growing animals. Herein, we evaluate the repeatability, practicality, and sensitivity of a resazurin-based assay for ranking bovine skeletal muscle biopsies based on metabolic activity. Six yearling Holstein heifers (body weight = 330 ± 11.3 kg) were fed 4 dietary treatments consisting of high or low rumen-degradable starch and fiber arranged factorially in a partially replicated Latin square design. Periods were 18 d, consisting of 3 d for diet transition, 14 d for diet adaptation, and 1 d for sample collection. Semitendinosus biopsies were collected into ice-cold Dulbecco's modified Eagle medium (Fisher Scientific, Hampton, NH) from each heifer during each period. Analysis was initiated within an hour of sample collection. To assess tissue metabolic rate, biopsies were transferred to Dulbecco's modified Eagle medium with resazurin and incubated at 37°C. Fluorescence of each sample was read at time 0 and at 15-min intervals for 2 h. Change in fluorescence was representative of skeletal muscle reducing equivalent production. Fluorescent signal strength increased with time and relative rank of treatments did not change with time; accordingly, future studies may compare fluorescence at a single time point. Change in fluorescence at 120 min was used for analysis of the fixed effects of fiber, starch, and animal when accounting for a random effect of period. Samples collected when animals were on a high-ruminally degradable starch diet were more metabolically active than samples collected from animals on low-starch diets. Significant differences in metabolic activity among individual animals were also identified. Average relative fluorescence was correlated with dry matter intake, average daily gain, and feed-to-gain ratio. The relative fluorescence tended to correlate with average daily gain (r = 0.749) and feed-to-gain ratio (r = ?0.783); change in fluorescence did not correlate with dry matter intake. Although evaluated on a small sample size, this technique shows promise as a potential means of ranking animals by growth or feed efficiency. Further work on a larger experimental population is needed to confirm the usefulness of this assay as a consistent and reliable predictor of these important phenotypic parameters. 相似文献