大豆异黄酮抑制胃癌细胞生长作用的研究

本实验以人胃癌SGC-7901细胞为体外实验模型,通过MTT实验,分裂指数法和集落形成实验,筛选具有较强抑制胃癌细胞生长作用的大豆异黄酮单体成分。结果表明游离形式的金雀异黄素的抑癌效果最为显著,其他形式的金雀异黄素苷和黄豆苷体外抑制细胞生长作用不明显。金雀异黄素代谢前体物鸡豆苷素亦有较显著的抑制效果,但作用迟缓。苷元形式的大豆异黄酮抑制肿瘤细胞生长作用明显强于苷类形式的大豆异黄酮,三羟异黄酮金雀异黄素是大豆异黄酮发挥生物学作用的最有效单体成分。     

大豆异黄酮对HepG2细胞胆固醇代谢的作用及其机制

目的:对大豆异黄酮降低胆固醇作用及其机制进行探讨,并比较金雀异黄素(Gen),大豆素(Dai)和雌马酚(Eq)的作用强弱。方法:采用MTT检测细胞增殖状况,采用试剂盒检测LDL-C、TC和apoA-I的表达,采用实时定量PCR检测mRNA的表达。结果:大豆异黄酮可以增加细胞内胆固醇含量,增加LDL-C的摄取量和apoA-I的分泌量,其中Gen的作用最为明显,Eq的作用较弱。PPARγ和LXRα的mRNA表达量增多。结论:大豆异黄酮能够调节细胞胆固醇代谢,其作用可能是通过调节PPARγ/LXRα通路实现的。     

超高效液相色谱-串联质谱法测定大豆中3种异黄酮素

目的建立超高效液相色谱-串联质谱法测定大豆中金雀异黄素(genistein)、大豆苷元(daidzein)和黄豆黄素(glycitein)的含量。方法样品经过乙醇-水(3:1,V:V)提取,用AcquityUPLC?HSST3柱(3.0mm×150mm,1.8μm)分离,以甲醇和0.1%甲酸溶液作为流动相进行梯度洗脱,电喷雾负离子模式(electrospray ionization, ESI-)电离,多反应监测模式(multiple reaction monitoring mode, MRM)进行检测。结果金雀异黄素、大豆苷元和黄豆黄素在2.0～200μg/L范围内线性关系良好(r20.999),方法的检出限分别为0.5、0.4、0.1 mg/kg,在2.5、10.0、40.0 mg/kg添加水平的平均回收率为79.3%～107%,相对标准偏差(n=6)为1.3%～6.8%。结论方法简单、灵敏、准确可靠,适用于大豆中金雀异黄素、大豆苷元和黄豆黄素等3种异黄酮素含量的测定。     

高效液相色谱法测定六种大豆异黄酮及雌马酚的含量

针对豆制品中同时测定大豆异黄酮和雌马酚方法存在的问题,优化并建立了同时测定6种大豆异黄酮和雌马酚的高效液相检测程序,并测定了几种市售豆乳中大豆异黄酮的含量。采用乙腈/甲醇（v/v,5/2）和水为流动相、流速1.0mL/min、检测波长254nm,6种大豆异黄酮和雌马酚均得到良好的分离,相关系数R2分别为0.9998、0.9989、0.9997、0.9986、0.9998、0.9995、0.9999,线性关系良好。该方法准确、灵敏,适合于豆制品中大豆异黄酮及雌马酚的检测。     

盐酸水解大豆异黄酮的工艺研究

研究了用酸水解大豆异黄酮分子上的部分糖基，使异黄酮部分水解生成低糖，高活性苷元的方法。并通过HPLC分析得到大豆异黄酮酸解最佳反应条件为：0.1mol/L盐酸：时间3h；温度40℃；盐酸体积原料比5:1。金雀异黄素含量5.95%，分解率为5.25%。     

大豆异黄酮代谢终产物——雌马酚的研究进展

雌马酚是大豆异黄酮在人体肠道中的最终代谢产物。众多研究表明大豆异黄酮具有广泛的保健价值,在预防心血管疾病、乳腺癌和前列腺癌等方面均发挥重要作用。大豆异黄酮的生物活性在某种程度上归因于雌马酚,并且雌马酚具有较其前体更高的生物学效用。大豆异黄酮在特定的肠道菌作用下降解产生雌马酚,但并非每个人体内都可代谢产生雌马酚。总结了雌马酚在人体中的生理活性,并且综合论述了化学合成制备混合型雌马酚的方法,以及生物合成雌马酚过程中,动物及人体内可降解大豆异黄酮的肠道菌筛选情况。     

测定雌马酚的紫外法建立与应用

分别以雌马酚标准品和食用大豆异黄酮人的尿液为样品,建立一种测定雌马酚的紫外分析方法。考察方法的特性及测定结果可靠性,其结果为:检出限5×10-10g/mL,定量限15×10-10g/mL。应用于人尿液雌马酚的测定,精密度4.45%,回收率100.25%,结果可靠。新建立的紫外法达到了定量分析的要求,同时具有操作简单、快速、测定成本低的优点,适合大批量样品的测定。     

雌马酚对人乳腺癌MCF-7细胞生长的影响

目的：观察雌马酚在不同浓度水平下对雌激素依赖阳性人乳腺癌MCF-7细胞生长的影响。方法：采用MTT法检测细胞增殖,流式细胞术分析细胞周期分布情况。结果：MCF-7细胞经去雌激素处理以后,与对照组相比,雌马酚在10-6～10-5mol/L时可显著抑制细胞增殖,使S期细胞增多,其抑制作用可被雌激素受体特异性抑制剂ICI-182780阻断。结论：雌马酚对人乳腺癌细胞MCF-7的细胞增殖具有抑制作用,可干扰DNA的复制,具有一定的雌激素样作用,且其抑制作用可能是通过雌激素受体（ER）介导的。     

1 株素食者产雌马酚肠道菌的分离与鉴定

以素食者粪便为样品,大豆异黄酮为底物,对产雌马酚的肠道菌进行分离培养及鉴定。采用紫外光谱法对雌马酚定性、定量测定,用肉眼观察、扫描电镜、生理生化、16S rDNA全序测序方法对分离得到的LJ-G1肠道菌进行菌株鉴定。结果表明：麦康凯和BHI培养基、厌氧平板划线培养法更适于产雌马酚肠道菌的分离筛选。采取10 g粪样稀释到10-5接种,在pH 7.3、温度37 ℃、厌氧培养36 h的条件下,培养基中雌马酚产出量达到10 μg/mL以上。经鉴定分离得到的LJ-G1菌株为G－杆菌;根据生理生化反应结果,查阅《常见细菌系统鉴定手册》,确定LJ-G1为河生肠杆菌;16S rDNA全序测序显示与肠杆菌同源性达99%。     

紫外分光光度法测定大豆总异黄酮的含量

为建立一种检测食物中大豆异黄酮含量的快速分析方法 ,以大豆中的活性成分金雀异黄素为标准品 ,在其紫外最大吸收峰 2 59nm处测定大孔吸附树脂法配合溶剂法提取制得的大豆异黄酮试样的含量 ,大豆异黄酮试样中总异黄酮的含量以金雀异黄素计算为 38.7%。平均加样回收率为99.86% ,相对标准偏差为 2 .6% ,方法简便 ,重现性好 ,可作为检测大豆异黄酮含量的一种手段。     

Determination of Major Isoflavones in Soy Drinks by Solid-Phase Micro Extraction Coupled to Liquid Chromatography

A simple method for determination of major isoflavones (daidzein, genestein, genistin) and equol, a daidzein metabolite, has been developed using solid-phase micro extraction coupled to liquid chromatography with diode array UV detection. All the aspects influencing adsorption (fibre coating, extraction time, temperature, pH and salt addition) and desorption of the analytes (desorption and injection time and minimize carryover) were carefully investigated. The limits of detection obtained using a polydimethylsiloxane /divinylbenzene fiber coating were in the range 4 (genistein) to 38 (genistin) nM. The method proved to be useful for determination of analytes in soy-based products. Daidzein, genistein, and genistin were found in all samples (three soy milks and two blended rice/soy beverages) at concentrations ranging from 0.8?±?0.2 (daidzein) to 180.4?±?12.1 (genistin) μM, while glycitein and equol were found in three and in one of the drinks at levels between 1.7?±?0.1 and 5.0?±?0.2 μM and at 2.7?±?0.2 μM, respectively. The procedure was used to define the binding constants of isoflavones with serum albumin bovine that were found from 2.5?×?10⁴ (daidzein) to 2.9?×?10⁵ (genistein) L mol^?1. The method proposed restricts the use of organic solvents and can be used widely in most laboratories with standard equipment. In addition, it is suitable for easily studying the isoflavone interaction with the main constituents in plants, e.g., proteins and lipids, to evaluate their bioavailability and to clarify the controversial question on benefits for or damage to human health resulting from soy intake.     

Al3+荧光增敏快速检测酸奶和乳酸菌饮料中的胭脂虫红酸（英文）

研究溶剂、浓度、pH值以及金属离子对胭脂虫红酸荧光性能的影响,表明胭脂虫红酸在pH 4且其物质的量浓度为2.0×10^-4 mol/L的水溶液中荧光最强;而胭脂虫红酸对金属离子选择性识别的结果显示,Al^3+能使胭脂虫红酸的荧光强度显著增强从而提高检测的灵敏度。以Al^3+(2.0×10^-3 mol/L)为标准溶液检测样品中胭脂虫红酸含量时,胭脂虫红酸的物质的量浓度在1.0×10^-5~8.0×10^-5 mol/L范围内与其荧光强度呈良好的线性关系,检测限为5.0×10^-6 mol/L。实际应用结果表明,用荧光法检测不同酸奶和乳酸菌饮料中添加的胭脂虫红酸的含量,样品回收率在96.6%~110.5%之间,相对标准偏差小于5.9%。本研究为快速、有效、定量地检测食品中的胭脂虫红酸提供了一种有效的方法。     

10-HDA对体外培养大鼠小脑细胞增殖的影响

目的:探讨不同浓度的10-HDA对体外培养大鼠小脑神经细胞的增殖和存活的影响。方法:将不同浓度的10-HDA加到原代培养的新生大鼠小脑神经细胞中,使其终浓度分别为0.1μmol/L、1.0μmol/L、10μmol/L、通过BrdU染色,尼氏染色,MTT的方法来检测10-HDA对体外培养大鼠小脑神经细胞增殖和存活的影响。结果:不同浓度的10-HDA均能促进小脑细胞的增殖和存活,并且有一定的浓度依赖关系。中浓度组(10-HDA终浓度为1.0μmol/L)的效果最为显著,与对照组相比有显著性差异(p<0.01)。结论:10-HDA有助于小脑神经细胞的增殖和存活。     

Utilizing the R-Index Measure for Threshold Testing in Model Soy Isoflavone Solutions

ABSTRACT: Twenty-eight untrained panelists used the signal detection rating method to determine thresholds for daidzein and genistein. Five concentrations of genistein and daidzein were suspended in starch solutions. The starch solution represented the noise, and isoflavone suspensions represented the signal. Blindfolded panelists received 15 replicates of noise and signal. To determine group detection thresholds, the concentration at an R-index of 75% was calculated. The group thresholds for genistein and daidzein were 4.006 × 10⁻³ M and 2.921 × 10⁻³ M, respectively. These results indicate a much higher threshold value than reported in the literature and in soymilks. This strongly suggests that daidzein and genistein individually do not contribute to bitterness or astringency in soy food products.     

High levels of equol in organic skimmed Finnish cow milk

The isoflavonoids, equol, formononetin, daidzein, genistein, biochanin A, and O-demethylangolensin (O-DMA), were analyzed from commercial cartons of skimmed Finnish milk by HPLC-diode array detector (DAD)-FL. We found 411 +/- 65 ng/mL of equol and traces of formononetin and daidzein in organic skimmed milk whereas conventionally produced milk contained 62 +/- 16 ng/mL of equol and no formononetin or daidzein.     

偏钒酸钠促进大豆芽异黄酮类物质黄豆苷元和染料木黄酮合成的研究

目的:分析比较偏钒酸钠对大豆芽合成异黄酮类物质-黄豆苷元和染料木黄酮的影响;方法:将大豆种子在不同浓度的偏钒酸钠水溶液(0、200、400、600、800、1000、1200、1400、1600mg/LNaVO3)于28℃萌发6d,第6d收获富钒大豆芽,洗净烘干至恒重,用95%乙醇提取大豆芽中的异黄酮类物质-黄豆苷元和染料木黄素,黄豆苷元和染料木黄素含量由高效液相色谱法测定;结果:分析测定结果表明,当大豆种子在浓度为200～600mg/L偏钒酸钠溶液中于28℃萌发6d,收获的大豆芽中的异黄酮类物质黄豆苷元和染料木黄酮的含量高于同等条件下其他浓度偏钒酸钠萌发液中萌发的大豆芽;结论:综合大豆芽的生长情况及大豆芽中异黄酮类物质-黄豆苷元和染料木黄酮含量等因素,在本实验条件下,萌发富钒大豆芽的适宜偏钒酸钠酸浓度为200～600mg/L,适宜的培育时间为96～120h,适宜温度为28℃。     

Combination of low dose of genistein and daidzein has synergistic preventive effects on isogenic human prostate cancer cells when compared with individual soy isoflavone

The reduced incidence of prostate cancer (PCa) in Asia countries has been attributed to high soy diets, and major soy isoflavones, in particular daidzein and genistein, are thought to be the source of the beneficial and anti-cancer effects of soy foods. However, attention has been drawn to the safety of using high levels of soy isoflavones in humans, which is especially the concern for consumers taking regular soy isoflavone dietary supplements. The main objective of this study is thus to identify a soy isoflavone combination with lower levels of daidzein and genistein to be a more efficacious and safer chemo-preventive agent for PCa. The anticancer effects of daidzein and genistein, and their combinations on early-stage androgen-dependent PCa cells (LNCaP) and bone metastatic LNCaP-derivative PCa cells (C4-2B) were compared. Cells were treated with varying concentrations of daidzein, genistein (25–200 μM) or their combinations (25 or 50 μM) and cell proliferation, apoptosis, cell cycles and cellular uptakes of the isoflavones were measured after 48 h. Daidzein and genistein showed a synergistic effect on inhibiting cell proliferation and inducing apoptosis of both PCa cells. Twenty-five μM daidzein/50 μM genistein and 50 μM daidzein/50 μM genistein significantly increased the apoptotic effects on C4-2B cells although they did not show any effect when used individually. Except 50 μM daidzein/50 μM genistein, all other combinations had no impacts on cell cycles. For treatment with soy isoflavone combination, genistein was always better taken up than daidzein by both LNCaP and C4-2B cells.     

Aquatic photochemistry of isoflavone phytoestrogens: degradation kinetics and pathways

Isoflavones are plant-derived chemicals that are potential endocrine disruptors. Although some recent studies have detected isoflavones in natural waters, little is known about their aquatic fates. The photochemical behaviors of the isoflavones daidzein, formononetin, biochanin A, genistein, and equol were studied under simulated solar light and natural sunlight. All of these phytoestrogens were found to be photolabile under certain conditions. Daidzein and formononetin degraded primarily by direct photolysis. Their expected near-surface summer half-lives in pH 7 water at 47° latitude are expected to be 10 and 4.6 h, respectively. Biochanin A, genistein, and equol degraded relatively slowly by direct photolysis at environmentally realistic pH values, though they showed significant degradation rate enhancements in the presence of natural organic matter (NOM). The indirect photolysis rates for these compounds scaled with NOM concentration, and NOM from microbial origin was found to be a more potent photosensitizer than NOM from terrestrial sources. Mechanistic studies were performed to determine the indirect photolysis pathways responsible for the rate enhancements. Results of these studies implicate reaction with both singlet oxygen and excited state triplet NOM. Environmental half-lives for biochanin A, genistein, and equol are expected to vary on the basis of pH as well as NOM source and concentration.     

Comparison of the in vitro metabolism of isoflavones by fecal flora from human flora‐associated mice and human

Recently there has been great interest in the biological effects of equol (4′,7‐dihydroxyisoflavan), a metabolite of daidzein produced by intestinal flora. In this study, the in vitro metabolism of daidzein, daidzin and genistein by fecal flora, in human flora‐associated (HFA) mice and a human donor was investigated. The in vitro incubation of feces with isoflavones demonstrated that the potential for equol production had been successfully transferred from human feces to HFA mice. The average equol concentrations were higher in feces from HFA mice than in those from their donor. In both HFA mice and their donor, the fecal equol production from daidzin was comparable to that from daidzein. The results suggest that daidzin would be an effective substrate for bacterial equol production in vivo. The HFA mice produced in these experiments and maintained in an isolated environment might also be useful for investigating the biological activity of equol in detail. Copyright © 2006 Society of Chemical Industry