大豆异黄酮改善高血脂小鼠记忆的研究

目的:探讨大豆异黄酮(SI)对高血脂小鼠记忆的影响及有关机制。方法:将小鼠分为4组,基础饲料对照组;高脂饲料对照组;低剂量SI组:高脂饲料+SI(50mg/kgbw);高剂量SI组:高脂饲料+SI(100mg/kgbw)。连续灌胃SI30d后,测定小鼠记忆能力,并检测血清总胆固醇(TC)、甘油三酯(TG)和β-脂蛋白含量及超氧化物歧化酶(SOD)活力,血液、大脑皮质和海马中胆碱酯酶(AChE)活性以及大脑皮质和海马中氨基酸神经递质(Asp、Glu和Gly)含量。结果:在实验期内造成高脂模型,与对照组比较,高血脂小鼠记忆明显降低,而SI明显改善高血脂小鼠记忆能力,同时使小鼠血清中TC、TG和β-脂蛋白含量以及大脑皮质和海马中AChE活力显著降低,而血清SOD活力及大脑皮质和海马中氨基酸神经递质含量显著提高。结论:SI可改善高血脂小鼠的记忆,其机制可能与其抗氧化作用及调节神经递质的代谢有关。     

染料木素对大鼠成骨细胞增殖与分化的影响

目的:探讨染料木素体外对大鼠成骨细胞增殖与分化的影响。方法:用改良的组织块法分离培养新生大鼠颅骨成骨细胞,染料木素以不同浓度加入细胞培养体系,作用不同时间后,用MTT法检测成骨细胞的增殖情况;用对硝基苯二钠基质动力学法测定细胞内碱性磷酸酶的活性,用改良的Lowry法测蛋白含量。结果:染料木素在1×10~(-5)～1×10~(-9)mol/L浓度范围内作用24h、48h均能促进成骨细胞增殖,在1×10~(-7)～1×10~(-5)mol/L范围内作用72 h可提高成骨细胞内碱性磷酸酶的活性。结论:染料木素体外能促进成骨细胞的增殖与分化。     

Sources of Phytoestrogen Exposure among Non-Asian Women in California, USA

Objective: We recently described the development of a comprehensive database for assessing phytoestrogen exposure in epidemiologic studies [1]. This paper describes the first application of this database and the primary sources of phytoestrogen consumption in non-Asian women. Methods: Four hundred and forty-seven randomly selected African-American, Latina, and white women, ages 50 79 years, residing in California's San Francisco Bay Area and participating as controls in an ongoing population-based case-control study of breast cancer, were included in the present analysis. Average daily consumption of each of seven phytoestrogenic compounds was determined for each woman by combining the values from the new database with food consumption reported on a food-frequency questionnaire. Results: Phytoestrogens in the non-Asian Bay Area diet appear to come primarily from: (1) traditional soy-based foods (e.g. tofu and soy milk); (2) "hidden" sources of soy (e.g. foods containing added soy protein is concentrate, or soy flour, e.g. many brands of doughnuts and white bread); and (3) a variety of foods which contain only low to moderate amounts of phytoestrogens per 100 grams but which are frequently consumed (e.g. coffee and orange juice). Conclusions: In the absence of a comprehensive assessment of various phytoestrogens in a wide variety of foods, epidemiologic studies could suffer from the effects of uncontrolled confounding by unmeasured sources of phytoestrogen exposure potentially leading to biased estimates of effect and misinterpretation of findings.     

The specific role of isoflavones in reducing prostate cancer risk

AIMS: To evaluate the effectiveness of supplementing a group of early stage prostate cancer patients, with 60 mg of soy isoflavones in producing a change in hormonal and proliferative risk parameters that are implicated in prostate cancer promotion. METHODS: Seventy six eligible prostate cancer patients with a Gleason score of 6 or below, between ages 50 and 80 were admitted and supplemented with soy isoflavones or placebo for a 12 week period and changes in PSA and steroid hormones were analyzed at baseline and post intervention. RESULTS: Fifty-nine patients completed the 12-week intervention. Serum free testosterone was reduced or showed no change in 61% of subjects in the isoflavone group compared to 33% in the placebo group. Serum total PSA decreased or was unchanged in 69% of the subjects in the isoflavone treated group compared to 55% in the placebo group. However, we did not see an increase in SHBG levels. Nineteen percent of subjects receiving soy isoflavones reduced total PSA by two points or more during the intervention period. CONCLUSIONS: These data suggest that supplementing early stage prostate cancer patients with soy isoflavones, even in a study of short duration, altered surrogate markers of proliferation such as serum PSA and free testosterone in a larger number of subjects in the isoflavone supplemented group than the group receiving placebo. The study establishes the need to explore further the effects of prolonged and consistent soy consumption, which could potentially delay onset of histologic disease in this patient population.     

Emerging evidence on the role of soy in reducing prostate cancer risk

Soyfoods are a unique dietary source of isoflavones, which have both hormonal and non-hormonal effects relevant to prostate cancer prevention. In vitro, the main soybean isoflavone, genistein, inhibits prostate cancer cell growth; in animals, most but not all studies show isoflavonel rich soy protein and isolated isoflavones inhibit prostate tumor development. Currently, although only limited epidemiologic data indicate soy intake reduces prostate cancer risk, results from a pilot intervention trial suggest isoflavones may be beneficial to prostate cancer patients. For several reasons, men concerned about their prostate health may consider incorporating soy into their diet.     

Soy consumption and phytoestrogens: effect on serum prostate specific antigen when blood lipids and oxidized low-density lipoprotein are reduced in hyperlipidemic men

PURPOSE: Herbal remedies high in phytoestrogens have been shown to reduce serum prostate specific antigen (PSA) and have been proposed as a treatment for prostate cancer. Soy proteins used to lower serum cholesterol are rich sources of phytoestrogens. Therefore, we assessed the effect of soy consumption on serum PSA in men who had participated in cholesterol lowering studies. MATERIALS AND METHODS: For 3 to 4 weeks 46 healthy middle-aged men with a range of starting PSA values took soy (mean 44 gm. soy protein daily, 116 mg. isoflavones daily) or control foods, and a subgroup of men took a lower level of soy supplements for 3 months. PSA was measured at the start and end of each treatment. RESULTS: Soy had no significant effect on serum total or free PSA, independent of PSA starting value or isoflavone intake. The lack of effect on PSA was seen, although soy intake was sufficient to reduce low-density lipoprotein cholesterol (5.8 +/- 2.2%, p = 0.012), the estimated coronary heart disease risk (6.1 +/- 2.8% for 10 years, p = 0.032) and the serum concentration of oxidized low-density lipoprotein measured as conjugated dienes (9.5 +/- 3.4%, p = 0.008) in the 3 to 4-week study. In addition, the lack of effect of soy on PSA persisted for the 3 months of the extended study. CONCLUSIONS: At levels of soy intake which reduce low-density lipoprotein cholesterol any potential benefits of soy consumption on prostate cancer are likely to occur for reasons other than alterations in hormone activity.     

依普黄酮固体分散体在大鼠的药物动力学评价(英文)

目的:评价依普黄酮固体分散体在大鼠体内的药物动力学行为。方法:测定它的药物动力学参数和相对生物利用度,采用高压液相色谱法测定大鼠血浆中依普黄酮的浓度。结果:大鼠灌胃依普黄酮固体分散体250mg·kg~(-1),其血药浓度-时间曲线符合一室模型,药物动力学参数为:K_e=0.21h~(-1),T_(1/2K_e)=5.19h,K_a=1.71h~(-1),T_(1/2K_a)=0.41h,T_(max)=0.67h,C_(max)=429μg·L~(-1),AUC=3916μg·h·L~(-1),相对生物利用度是323％。结论:依普黄酮固体分散体与依普黄酮的物理混合物比较,在大鼠体内有更多被吸收。     

Isoflavones inhibit intestinal epithelial cell proliferation and induce apoptosis in vitro.

There have been many reports that high soya-based diets reduce the risk of certain types of cancer. This effect may be due to the presence of high levels of isoflavones derived from the soya bean, particularly genistein which has been shown to be a protein tyrosine kinase (PTK) inhibitor and have both oestrogenic and anti-oestrogenic properties. We have examined the effect of genistein and a number of novel synthetic analogues on both normal (IEC6, IEC18) and transformed (SW620, HT29) intestinal epithelial cell lines. Responses were compared to those elicited by oestradiol, the anti-oestrogen tamoxifen, and the tyrosine kinase inhibitor tyrphostin. Genistein and tamoxifen were potent inhibitors of cell proliferation. Of seven novel isoflavones tested, none were more potent inhibitors than genistein, and all displayed similar relative activities across the different cell lines. In addition to inhibiting cell proliferation, cell death via apoptosis was observed when the cells were exposed to the isoflavones and all but one exhibited PTK inhibitory activity. These data suggest that by reducing proliferation and inducing apoptosis, possibly due in part to PTK inhibition, isoflavones may have a role in protecting normal intestinal epithelium from tumour development (reducing the risk) and may reduce colonic tumour growth.     

大豆异黄酮对围绝经期大鼠子宫作用及机制研究

目的:研究不同剂量及大豆异黄酮(SI)对围绝经期大鼠子宫以及子宫雌激素受体亚型ERα、ERβ表达的影响,探讨SI对子宫的作用及机制。方法:设7月龄雌性SD大鼠为正常组,将11月龄雌性SD大鼠随机分为五组:模型组,己烯雌酚组和3个SI给药组(分别灌胃SI30、12、4.6mg/kg·d),35d后,HE染色、扫描电镜观察子宫内膜形态,放射免疫检测血清雌二醇(E2)、卵泡刺激素(FSH)、黄体生成素(LH)、睾酮(T)含量,免疫组化观察SI对子宫ERα,ERβ表达的影响。结果:低剂量SI可提高11月龄大鼠血清雌二醇水平而高剂量SI组雌二醇水平明显低于7月龄正常组动物,各剂量SI均能促进子宫内膜腺体发育和内膜上皮无纤毛细胞上的微绒毛生长,无明显剂量依赖趋势。高剂量SI能明显提高围绝经期雌鼠子宫中降低的ERβ水平而对ERα无显著影响。结论:大豆异黄酮对围绝经期雌鼠子宫有雌激素样作用并且对ERβ表达具有调节作用。     

海洋碳样小单孢菌产生的大豆黄素和染料木素

目的研究海洋微生物FIM02—635产生的活性次级代谢产物。方法对产生菌进行分类鉴定。发酵液用有机溶媒提取具有免疫抑制活性的化合物，采用硅胶柱层析及高速逆流色谱的分离方法，提取纯化到2个化合物FW63511和FW63512，通过理化性质测定和光谱学测定分析2个化合物的结构并对这两个化合物进行体外生物活性测定。结果与结论产生菌定名为碳样小单孢菌FIM02—635。FW63511和FW63512分别与异黄酮大豆黄素和染料木素同质，它们具有免疫抑制和抗肿瘤活性，但没有抗菌活性。