大豆异黄酮与心血管疾病

流行病学调查显示，日本人心血管疾病死亡率与美国人有显著差异。研究表明亚洲人心血管疾病的低发病率可能与亚洲人饮食中的大豆食品所含的异黄酮物质，主要是金雀异黄素和大豆苷元有关。本文就大豆异黄酮对于防治动脉粥样硬化和相应的心血管疾病的有益作用进行综述。     

大豆异黄酮的药理作用Ⅰ

大豆异黄酮包括金雀异黄素(Genistein)、大豆甙元(Daidzein,又称大豆黄酮)及其相应的葡萄糖甙:金雀异黄甙(Genistin)和大豆甙(daidzin),天然状态下多以甙的形式存在。大豆及大豆制品都含有异黄酮,如大豆粉中含2014μg/g,豆腐中含531μg/g干重,大豆分离蛋白中含987μg/g,大豆农缩蛋白中含73μg/g,大豆速溶饮料中含1918μg/g干重。流行病学调查和生物医学研究均发现大豆及大豆制品有广泛的生物功效,如防治癌症、降低血脂、抗动脉粥样硬化和改善妇女更年期症状等,这均和它所含大豆异黄酮有关。本文对大豆异黄酮的主要药理作用作一综述。 1 抗氧化作用 金雀异黄素含5,7,4′三个酚羟基,大豆甙元含7,4′二个酚羟基。酚羟基作为供氢体能与自由基反     

大豆异黄酮雌激素样作用与骨质疏松的防治

此文综述了近年来大豆异黄酮防治骨质疏松作用的研究进展。大豆异黄酮作为一种植物雌激素可模拟雌激素作用于骨骼系统,调节骨吸收和骨形成,有防治骨质疏松的作用。同时,大豆异黄酮与雌激素作用又有不同,如对子宫等生殖器官作用小,有降低肿瘤及心血管病发生风险等有益作用,故值得进一步研究大豆异黄酮药理作用机制。     

大豆异黄酮预防心血管疾病的研究进展

大豆异黄酮是一类存在于豆类食物中的植物雌激素,由于其类雌激素样作用,富含大豆异黄酮豆类食品对心血管等疾病具有防治作用而备受研究者关注,本文就大豆异黄酮对心血管疾病在流行病学、动物实验和临床试验等近几年的研究进展情况作一概述。     

大豆异黄酮对高脂去卵巢兔血脂及动脉粥样硬化形成的影响

目的研究大豆异黄酮对进食高脂饲料去卵巢兔血脂及动脉粥样硬化形成的影响。方法雌性3个月龄新西兰兔32只,随机分为正常对照组、高脂去卵巢组、大豆异黄酮组、雌二醇组。实验期8周,实验结束时检测血清总胆固醇(TC)、低密度脂蛋白胆固醇(LDL-C)、高密度脂蛋白胆固醇(HDL-C)、甘油三酯(TG)浓度,观察并用计算机图像分析粥样斑块面积。结果高脂去卵巢组与其他3组比较,血清TC、LDL-C、TG浓度显著增高(P<0.05),粥样斑块面积显著增大(P<0.05)。大豆异黄酮组与高脂去卵巢组比较,血清TC、LDL-C、TG浓度显著降低(P<0.05),粥样斑块面积显著减少(P<0.05)。结论大豆异黄酮对高脂饲料造成的雌激素缺乏兔血脂增高及动脉粥样硬化形成具有抑制作用。     

大豆异黄酮与疾病防治

异黄酮是良好的抗氧化剂，主要存在于大豆中。研究显示其具有雌激素样作用，抗肿瘤作用及预防骨质疏松，防治糖尿病、肾病等作用，因而日益受到关注。本文综述了大豆异黄酮的分类与代谢，以及近年来有关大豆异黄酮与肿瘤防治、与骨代谢的关系、对糖尿病、肾病、高脂血的影响及作用机制等方面的研究进展。     

葛根异黄酮类化合物抗动脉粥样硬化药理研究进展

动脉粥样硬化(Atherosclerosis,AS)是当今导致心脑血管疾病高发的主要因素,越来越多的报道说明中药葛根具有抗动脉粥样硬化的药理作用,其主要有效成分为异黄酮类化合物,以葛根素(puerarin)、大豆苷元(daidzein)和大豆苷(daidzin)研究最多,药理作用也最明显。文中对近年来葛根及其有效成分在动脉粥样硬化方面的研究进行综述。     

大豆异黄酮的开发利用

介绍近年来大豆异黄酮的研究进展，包括大豆异黄酮的主要类型，及其抗肿瘤，防治心血管病，免疫系统作用，雌激素样作用等多种生物活性，其开发与利用具有广阔前景。     

大豆异黄酮对更年期妇女骨质疏松作用的临床研究

目的通过人体膳食干预试验,从临床上观察确定大豆异黄酮对更年期围绝经期妇女骨质疏松的作用。方法试验对象80例随机分为大豆异黄酮组和安慰剂组,试验对象按时按量服用24周并进行追踪观察。结果大豆异黄酮组挠骨和胫骨骨密度明显增加,有统计学意义。而安慰剂对照组挠骨和胫骨骨密度不但没有增加,而且稍有下降。结论通过此次研究证实大豆异黄酮可以作为雌激素替代物促进成骨细胞生长,使骨密度得到增加,可以防治更年期围绝经妇女骨质疏松。     

大豆异黄酮类防治骨质疏松的作用机制

从大豆异黄酮类化合物对骨形成、骨吸收以及骨髓基质细胞的成骨和成脂分化的影响3个方面,总结了近10年来用大豆异黄酮类防治骨质疏松症的作用机制,同时指出了今后可能的研究方向。     

Soy, isoflavones and atherosclerosis

Consumption of soy protein is associated with a lower risk of cardiovascular disease in man, and reduced atherosclerosis in a variety of experimental animals. Although a portion of the cardiovascular protective effects appears to be due to reductions in plasma lipoprotein concentration, in most people the magnitude of this effect is relatively small. In many, but not all studies using animal models, the reduction in atherosclerosis is in part independent of changes in plasma lipids and lipoproteins. This implies that there may be a direct effect on the arterial wall of one or more of the components in soyprotein that reduces susceptibility to atherosclerosis. The most actively studied components of soy protein that may be responsible for these anti-atherogenic effects are the isoflavones and various protein factions. Extraction of isoflavones and other alcohol-soluble components from soy protein lowers, but does not eliminate its ability to reduce atherosclerosis. Surprisingly, in most studies, adding back the isoflavone-rich alcohol extract to the previously extracted soy protein, or to another protein, does not restore its lipoprotein lowering or anti-atherogenic properties. This implies that alcohol extraction either destroys an active component of soy, alters the structural integrity of the soy proteins, or disassociates a required isoflavone-soy protein complex. Understanding the mechanism of this effect is an important goal for future research. Likewise, the sites of action on the arterial wall, and the mechanisms by which various soy components act to reduce atherosclerosis are just now being studied. The recent demonstration that expression of estrogen receptor alpha is required for atheroprotection by soy protein provides important new mechanistic insight. Other properties of soy, including antioxidant, anti-inflammatory and potentially antithrombogenic properties need to be explored more mechanistically before the full potential of dietary soy protein for the protection from cardiovascular disease will be known.     

蒙古黄芪异黄酮的测定与提纯工艺研究

目的:测定蒙古黄芪异黄酮的含量,并考查用大孔吸附树脂分离纯化异黄酮的方法。方法:本试验采用甲醇回流提取黄芪异黄酮,于262 nm波长处测定异黄酮的含量。结果:测得总异黄酮含量为1.34 mg/g,RSD为1.18%(n=3),加样回收率为99.25%,RSD为1.93%(n=6)。结论:采用直接比色法测量异黄酮是可行的;确定以NKA-12型大孔吸附树脂富集黄芪异黄酮比较合适。     

Non-digestive stachyose enhances bioavailability of isoflavones for improving hyperlipidemia and hyperglycemia in mice fed with high fat diet

This study examined the efficacy of non-digestive stachyose on enhancing the absorption of soy isoflavones to improve metabolic syndrome in C57/BL6 mice. UPLC-q/TOF-MS was employed to analyze the content of isoflavones in urine and faeces. Stachyose significantly increased urinary contents of total isoflavones, genistein, daidzein and glycitein in mice. Supplementation of stachyose, soybean isoflavones or a combination prevented high fat diet (HFD)-induced body weight gain, accumulated adipose, dyslipidemia and hyperglycemia in obese mice. Interestingly, co-supplementation of stachyose and isoflavones improved all the mentioned parameters more effectively than administration of stachyose or isoflavones alone. Histological observation of hepatic tissues also confirmed the beneficial effects of co-supplementation of stachyose and isoflavones. These findings suggest that co-ingestion of non-digestible oligosaccharides and polyphenols as normal diet is a promising potential strategy for managing or reducing the risk of metabolic syndrome, which will lead to new knowledge on whole soybean and have extensive application in development of healthy food.     

大豆异黄酮对去卵巢大鼠血液生化指标的影响

目的研究大豆异黄酮对去卵巢大鼠血液生化指标的影响。方法将4月龄雌性SD大鼠摘除卵巢，按体重分成6组，分别给予不同剂量的大豆异黄酮或／和钙粉。连续灌胃饲养二个半月后，断头处死，收集血样并测定生化指标，采集右股骨、右胫骨、子宫并称重。结果大豆异黄酮对大鼠体重和子宫重量均有影响，可抑制去卵巢大鼠的代偿性增重和促进子宫的生长。大豆异黄酮对去卵巢大鼠血清钙、磷和骨钙素的影响不大，碱性磷酸酶活性稍有降低，血清雌二醇和降钙素水平稍有提高，但这些实验给药组与模型B组的的大多未达到显著水平。结论大豆异黄酮对去卵巢大鼠血液生化指标有一定的调节作用，所起的作用类似于弱雌激素活性，大豆异黄酮与钙剂联合使用时调节作用更明显。     

Quantitative efficacy of soy isoflavones on menopausal hot flashes

AIM

This study aimed to quantitate the efficacy of soy isoflavones in the treatment of menopausal hot flashes.

METHODS

Model based meta-analysis (MBMA) was used to quantitate the efficacy of soy isoflavones. We conducted a systemic literature search to build a time–effect model for placebo and soy isoflavones in treating menopausal hot flashes. Studies were identified, subjected to inclusion and exclusion criteria, and reviewed.

RESULTS

From 55 articles, 16 studies of soy isoflavones met the inclusion criteria, and contained 65 and 66 mean effect values in placebo and soy isoflavone groups, respectively, from about 1710 subjects. Interestingly, the developed model was found to describe adequately the time course of hot flashes reduction after administration of placebo and soy isoflavones. Using this model, we found that the maximal percentage change of hot flashes reduction by soy isoflavones was 25.2% after elimination of the placebo effect, accounting for 57% of the maximum effects of estradiol (E_{max-estradiol} = 44.9%). However, a time interval of 13.4 weeks was needed for soy isoflavones to achieve half of its maximal effects, much longer than estradiol, which only required 3.09 weeks. These results suggest that treatment intervals of 12 weeks are too short for soy isoflavones, which require at least 48 weeks to achieve 80% of their maximum effects.

CONCLUSIONS

Soy isoflavones show slight and slow effects in attenuating menopausal hot flashes compared with estradiol.     

Effects of soy isoflavones on 17beta-estradiol-induced proliferation of MCF-7 breast cancer cells.

Based on the results of in vitro-experiments in practically estrogen-free media and in the absence of estrogen-beta receptors, soy isoflavones have been suspected to enhance proliferation of MCF-7 breast cancer cells. In this study the effects of soy isoflavones on MCF-7 cells were investigated in the presence and absence of estrogen, directly and in a metabolized form by testing sera of postmenopausal women supplemented with isoflavones. First, three concentrations of isoflavones (0.1, 1 and 10 mumol/l) were tested at increasing levels of 17-beta-estradiol (<10pM, 50, 100 and 500pM). Next, blood sera from women supplemented for two weeks either with 200mg isoflavones or with 2 mg 17-beta-estradiol per day, or the combination of both were investigated in an MCF-7 cell proliferation assay. Further, the samples were screened for changes in gene expression patterns of the MCF-7 cells with Gene Chip arrays. Only at unphysiologically low estrogen levels isoflavones led to minor proliferation-enhancing effects. In contrast, at estradiol levels of >20pM, isoflavones both tested directly and indirectly (metabolized) revealed significant anti-proliferative effects as well as in the proliferation and the gene chip assay. These findings emphasize the reported advantageous properties of isoflavones for postmenopausal women.     

Differential interaction of Sophora isoflavonoids with lipid bilayers.

The mechanisms of some biological effects exerted by flavonoids (e.g. activity against lipid oxidation, multidrug resistance modulation) may involve their interactions with lipid bilayers. Due to variety of substituents attached to the flavonoid nucleus individual isoflavones significantly differ in their properties; in particular they may differently interact with membranes. For this reason we have investigated the interactions of different isoflavones with lipid bilayers. The influence of four plant isoflavones on the phase transitions of dipalmitoylphosphatidylcholine (DPPC) and on liposome aggregation was studied, using microcalorimetry and absorption measurements, respectively. We found that isoflavones substituted with one or two prenyl groups less effectively induce liposome aggregation than more polar ones, possessing no prenyl groups. For aggregation-promoting compounds, rather small differences in the influence on phosphatidylcholine, phosphatidylserine and phosphatidylinositol liposomes were recorded. On the other hand, the alteration of DPPC phase transitions by prenyl-substituted isoflavones was more pronounced than changes induced by non-prenyl ones. On the basis of observed effects we conclude that prenyl-substituted isoflavones penetrate deeper into the lipid bilayer while more polar ones act closer to the membrane surface. Comparing our results with biological tests it seems that interactions with the hydrophobic core of membranes are responsible for the activity of the studied isoflavones.     

大豆异黄酮的开发及市场前景

目的:为我国医药企业及研究机构开发大豆异黄酮产品提供参考。方法:对大豆异黄酮的国内、外市场及开发现状进行较详细的分析。结果与结论:大豆异黄酮具有开发价值,市场前景广阔。     

HPLC对人血浆中葛根素及葛根黄酮的线性考察

目的:对葛根素及葛根黄酮进行人血浆的线性考察,据此检测葛根素、葛根黄酮及其制剂人体内的药动学行为。方法:用高效液相色谱法考察,色谱条件:流速=1mL·min~(-1);柱温:20℃;检测波长:250nm;进样量50μL;流动相:甲醇:水=25:75。结果:葛根素R=6.56,精密度试验RSD≤5.02％,平均回收率=(100.9±0.5)％,葛根素及葛根黄酮血浆测定的线性范围0.0295～0.708μg·mL~(-1)。结论:用高效液相色谱法可作为葛根素、葛根黄酮及制剂人体内药动学的检测手段,为检测葛根黄酮及制剂人体内的药动学行为提供了方法。