Eating to beat breast cancer: Potential role for soy supplements

Background: The study reviews the anticancer properties of naturalisoflavones which occur in especially high concentration in soybeans. Itconsiders the suitability of soybean products for clinical trials aiming toreduce the progression of breast cancer.Methods: Evidence is reviewed that plant isoflavones such asgenistein show cytostatic activity against human mammary cancer cell linesin vitro and can also suppress carcinogen-induced mammary cancer inyoung and mature rats.Results: Plant isoflavones are converted in the bowel to compoundswith potential antioestrogenic and antioxidative properties. These compoundsshow cytostatic activity for both oestrogen receptor-positive and negativehuman mammary cancer cell lines, and also inhibit growth and progress of therat mammary cancer model. The high content of soybean products in the diet ofAsian women has been postulated as one reason for their relatively low breastcancer incidence.Conclusion: Preclinical studies suggest that soybean products begiven priority for clinical trials in breast cancer protection. A pilot studycould test soy protein supplements as long-term adjuvant dietary treatmentafter primary surgery for early breast cancer, looking for a decrease in therisk of recurrence or of second primary tumours.     

The isoflavones mixture from Trifolium pratense L. protects HCN 1-A neurons from oxidative stress

Oxidative stress-induced neuronal cell death has been implicated in different neurological disorders and neurodegenerative diseases such as Alzheimer's disease and Parkinson's. Using the Alzheimer's disease-associated hydrogen peroxide (H(2)O(2)), we investigated the neuroprotective efficacy of a natural mixture of phytoestrogenic isoflavones (genistein, daidzein, biochanin A and formononetin) from Trifolium pratense L. (Red clover) against oxidative stress-induced cell death in human cortical cell line HCN 1-A maintained in culture. Neuronal viability was determined by MTT or trypan blue test and neuronal integrity by morphological analysis.The results obtained indicate that exposure of HCN 1-A cell cultures to hydrogen peroxide resulted in a concentration-dependent decrease in neuron viability. Concentration of H(2)O(2) ranging from 50 to 200 microg/ml were toxic to these cultures. A 24-hour pretreatment with 0.5, 1 and 2 microg/ml isoflavones extract significantly increased cell survival as evidenced by MTT or trypan blue test and significantly prevented the morphological disruption caused by H(2)O(2) as shown by microscopical inspection, indicating that neurons treated with isoflavones were protected from the cell death induced by H(2)O(2) exposure. These findings imply that the neuroprotective effect of isoflavones extract is partly associated with its antioxidant activity. Further, results of these investigations indicate that although isoflavones extract exert a neuroprotective effect, it do not promoted cortical neuron process outgrowth.     

联合补充大豆异黄酮和钙预防去势大鼠骨质疏松的实验研究

目的 研究联合补充大豆异黄酮和钙对去卵巢大鼠骨质疏松的预防作用。方法 将50只3月龄SD雌性大鼠摘除卵巢后按体重随机分成5组：假手术对照组、手术对照组、大豆异黄酮组（40mg／kgBW）、钙组（100mg／kgBW）、钙＋大豆异黄酮组（Ca100mg／kgBW＋SI40mg／kgBW）。连续灌胃饲养3个月后测定大鼠血清骨钙素，左侧股骨测定骨密度和骨钙含量、右侧股骨进行骨组织形态学计量分析。结果 Ca＋SI组血清BGP水平和股骨骨密度均高于其他去卵巢各组（P〈0．05），但低于Sham组（P〈0．05）；Ca＋SI组大鼠股骨的骨钙含量与Ca组、Sham组差异均无统计学意义；在去卵巢各组大鼠中手术对照组、大豆异黄酮组和钙组大鼠的骨小梁数目和骨小梁厚度显著减少，骨小梁间距明显增宽，与钙＋大豆异黄酮组相比有显著差异（P〈0．05）。结论 与单独补充大豆异黄酮或钙相比，大豆异黄酮与钙的联合应用能够更有效地预防去卵巢大鼠骨质疏松的发生。     

Role of Isoflavones in the Hypocholesterolemic Effect of Soy

Epidemiologic data suggest an inverse relationship between the consumption of soy isoflavones and cardiovascular disease risk. The aims of this review are to determine if isoflavones play a role in the hypocholesterolemic effect of soy and whether the studies realized with that scope were adequately designed. In humans, most studies have been performed in postmenopausal women. The results are inconsistent, however; some studies show a decrease in total cholesterol and low-density lipoprotein concentrations, and an increase in high-density lipoprotein levels, and other investigations fail to show any beneficial effect of soy isoflavones on lipid profiles. In most studies, beneficial effects could not be attributed with certainty to soy isoflavones. If these components have any health-protecting effect in humans, it is small in comparison with the effect of soy protein itself. There are currently not enough data to recommend the consumption of isoflavone supplements to lower plasma cholesterol levels.     

雪山芪的化学成分研究

目的 研究雪山芪He dysaram sikkimense Benth．ex Baker．var．rigidum Hand、-Mass．的化学成分。方法 采用反复硅胶柱层析分离纯化,通过理化常数测定和光谱分析鉴定化合物的结构。结果 从雪山芪干燥根中分离得到9个化合物。根据波谱分析和理化数据,鉴定出其中8个化合物分别为：羽扇豆醇(lupeol,1)、4′-羟基-7-甲氧基异黄酮(isoformononetein,Ⅱ)、4′-羟基-6,7-二甲氧基异黄酮(3-[4-hydroxyphenyl-6,7-dimetoxy-4H-1-benzopyran-4-one],Ⅲ)、熊果酸(ursolic acid,Ⅳ)、山嵛酸-α-单甘油酯(docosanooic acid-2,3-d．hydroxypropyl ester,Ⅴ)、二十四烷酸(lignoceric acid,Ⅵ)、β-谷甾醇(β-sitosterol,Ⅶ)及蔗糖。结论 以上化合物均为首次从该植物中分得。     

大豆胚轴甲醇提取物对糖尿病大鼠血糖、血脂及血清过氧化脂质的影响

[目的 ]研究大豆胚轴甲醇提取物对糖尿病大鼠血糖、血脂及过氧化脂质代谢的影响 .[方法 ]甲醇提取大豆胚轴中的异黄酮类和皂甙 ,以薄层色谱法、高效液相色谱法检测其组成 .给GK/Jcl糖尿病大鼠长期食用添加 10 0 g/kg大豆胚轴甲醇提取物的饲料 ,观察和测定相应生物化学指标 .[结果 ]长期食用大豆胚轴甲醇提取物的糖尿病大鼠的血糖水平下降 ,血清过氧化脂质降低 ,高密度脂蛋白胆固醇增高 ,血清总胆固醇和甘油三脂却无明显变化 .[结论 ]大豆胚轴甲醇提取物具有显著的降低血糖、改善糖耐量、降低脂质过氧化和升高高密度脂蛋白胆固醇的作用     

Soy-based formulas and phyto-oestrogens: a safety profile

Phyto-oestrogens are non-steroidal plant-derived compounds that possess oestrogenic activity and act as selective oestrogen receptor modulators (SERMs). Among the dietary oestrogens, the isoflavone class enjoy a wide-spread distribution in most of the members of the Leguminosae family, including such prominent high-content representatives as soybean. Phyto-oestrogen research has grown rapidly in recent years owing to epidemiological studies suggesting that diets rich in soy may be associated with potential health benefits. There is a paucity of data on endocrine effects of soy phytochemicals during infancy, the most sensitive period of life for the induction of toxicity. The safety of isoflavones in infant formulas has been questioned recently owing to reports of possible hormonal effects. Infants fed soy formula receive high levels of phyto-oestrogens in the form of isoflavones (genistein, daidzein and their glycosides). To date, no adverse effects of short- or long-term use of soy proteins have been observed in humans and exposure to soy-based infant formulas does not appear to lead to different reproductive outcomes than exposure to cow milk formulas. Soy formula seems to be a safe feeding option for most infants. Nevertheless, much closer studies in experimental animals and human populations exposed to phyto-oestrogen-containing products, and particularly soy-based infant formulas, are necessary.     

高效液相色谱法测定淡豆豉药材中异黄酮的含量

目的:建立高效液相色谱法测定淡豆豉中异黄酮含量。方法:采用HPLC法,色谱柱为YWG C18柱(250 mm×4.5 mm,10μm),以甲醇-水-乙酸(10:10:1)为流动相,流速为0.8 mL·min-1,检测波长260 nm,测定淡豆豉中染料木素(genistein)、大豆黄素(daidzein)含量。结果:染料木素及大豆黄素的线性范围分别为2.00-40.00μg·mL-1和2.64-52.70μg·mL-1,相关系数分别为0.9994和0.9993,不同产地的淡豆豉中异黄酮含量差异较大。结论:本法准确、简便、快速,对于控制和评价淡豆豉的品质有重要意义。     

大豆异黄酮活性组分对H2O2诱导的PC12细胞损伤的影响

目的:探讨大豆异黄酮活性组分对H2 O2 诱导的PC12细胞损伤的保护作用。方法:以H2 O2 损伤PC12细胞为氧化应激损伤的模型,采用光学显微镜观察细胞形态,MTT法判断细胞的存活率,LDH法检测细胞的损伤程度。结果:不同浓度大豆异黄酮能明显改善H2 O2 导致的细胞甲瓒减少,大豆异黄酮处理组细胞存活率明显高于H2 O2 处理组(P <0 .0 1) ;而LDH漏出率则明显低于H2 O2 处理组(P <0 .0 5 )。结论:大豆异黄酮活性组分对H2 O2 诱导的PC12细胞损伤具有保护作用。     

大豆异黄酮减缓绝经后妇女骨丢失的临床效应

目的:确定大豆异黄酮减缓绝经后雌激素缺失状态下骨丢失的生理效应及其有效剂量。方法:以骨量正常或低减的绝经后妇女87人为研究对象,随机单盲分为大豆异黄酮84 mg/d和126 mg/d两个剂量组及安慰剂对照组,另以绝经后妇女10人给予7-炔诺酮2.5 mg/d作为阳性对照组,追踪24 w,测定腰椎、股骨颈和Ward,s三角区试验前后的骨密度值。结果:试验后安慰剂对照组腰椎骨密度较试验前显著下降(P<0.05), 大豆异黄酮两组及雌激素对照组各部位骨密度试验前后无显著变化 (P>0.05);协方差分析表明,试验后大豆异黄酮126 mg/d组、和雌激素对照组腰椎部位骨密度均值及其变化率显著高于安慰剂组(P<0.05),回归分析表明大豆异黄酮对各部位的骨密度变化率均有显著的正向作用(P<0.05)。结论:大豆异黄酮84～126 mg/d可减缓绝经后妇女骨的丢失,维持骨密度的相对稳定,其显效剂量是126 mg/d。