Systematic review of soy isoflavone supplements on osteoporosis in women

Objective:To clarify the effect of soy isoflavones on prevention of osteoporosis,and the effective dosage of soy isoflavones and its duration.Methods:Random control trials that investigated the association of soy isoflavones and osteoporosis were included in the meta-analysis by researching MEDLINE,EMBASE and the Chinese Biomedical Database up to October 2011.The RevMan software was used for all of the statistical analysis.Results:The present meta-analysis found that soy isoflavones significantly increased the bone mineral density by 54%and decreased the bone resorption marker urinary deoxypyridinoline(DPD) by 23%compared to baseline in women. Using random effects model,the effect of isoflavones on bone mineral density(BMD) regarding menopausal status and isoflavone dose revealed higher weighted mean difference changes were found in postmenopausal women and isoflavone dose above 75 mg/d.Subgroup analysis of trials with menopausal status,supplement type,isoflavone dose and intervention duration that used soy isoflavone extracts resulted in significant diflerent overall effect of DPD using by random effects model.Sensitivity analysis indicated that the effect of soy isoflavones on BMD and DPD was robust.Conclusions:The present meta-analysis reveals that soy isoflavone supplements significandy increase bone mineral density and decrease the bone,resorption marker urinary DPD.It shows no significant effect on bone formation markers serum bone alkaline phosphatase. The significant effect of soy isoflavones on BMD and urinary DPD is relative to menopausal status, supplement type,isoflavone dose and intervention duration.

Estrogen Receptor α and β Expressions in Hypothalamus-pituitary-ovary Axis in Rats Exposed Lactationally to Soy Isoflavones and Bisphenol A

Objectives This paper aims to investigate the uterotrophic activities of lactational exposure to combination of soy isoflavones （SIF） and bisphenol A （BPA） and to examine estrogen receptor α （ERα） and estrogen receptor β （ERβ） expressions in hypothalamus-pituitary-ovary axis and uterus.Methods Maternal rats that were breeding about 8 litters were randomly divided into four groups with seven dams in each group.Dams in different treatment groups received corn oil （control）,150 mg/kg BW of SIF,150 mg/kg BW of BPA or combination of 150 mg/kg BW of SIF and 150 mg/kg BW of BPA,respectively,from postnatal day 5 to 11 （PND5-11） by gavage.On PND12 and PND70,10 female litters were killed and hypothalamus,pituitary,ovary and uterus were collected.ERα and ERβ expressions in these organs were detected with Western blotting assay.And vaginal opening time and estrus cycle were examined in animals fed for PND70.Results On PND12,the relative uterine weight of rats treated with ISF or BPA or their combination was significantly higher than that of untreated rats （P〈0.05）.But the relative uterine weight of rats in the co-exposure group was slightly lower than that in the group only exposed to SIF or BPA.On PND 70,however,the relative uterine weight in each treatment group was not statistically different from that in the control group （P〈0.05）.Vaginal opening time and estrus cycle in groups treated with SIF or BPA or their combination were similar to those in the control group （P〈0.05）.Exposure to SIF or BPA or their combination could up-regulate or down-regulate ERα and ERβ expressions in hypothalamus,pituitary,ovary and uterus on PND12 and PND70.These regulation patterns for ERα and ERβ were different in different organs at different time points.Conclusion Lactational exposure to ISF or BPA or their combination could induce uterotrophic responses in neonate rats,which disappeared in later life.But these data fail to suggest a possibility for synergic actions between SIF and BPA.It was also demonstrated that the uterotrophic effects of SIF and BPA exposure might,at least,involve modification of ERα or ERβ expressions in the hypothalamus-pituitary-ovary axis.

Effects of Dietary Soy Isoflavones on Feed Intake,Growth Performance and Digestibility in Juvenile Japanese Flounder(Paralichthys olivaceus)

An 8-week feeding trial was conducted to investigate the effects of dietary soy isoflavones on feeding intake,growth performance,and digestion of juvenile Japanese flounder(Paralichthys olivaceus).Four isonitrogenous(49% crude protein) and isoenergetic(20.1 MJ kg-1) diets were formulated to contain four graded levels of soy isoflavones,namely,0,1,4 and 8 g soy isoflavones in 1 kg of diet.Each diet was randomly fed to triplicate tanks of fish(Initial average weight:2.58 g ± 0.01 g),and each tank was stocked with 35 fish.No significant difference was observed among diets with levels of 0,1 and 4 g kg-1 soy isoflavones in feed intake,weight gain,feed efficiency ratio(FER),proximate composition of fish whole body and apparent digestibility coefficients(ADC) of nutrients and energy(P>0.05).However,high dietary soy isoflavones level(8 g kg-1) significantly depressed weight gain,FER,whole-body crude lipid content of fish and ADC of nutrients(P<0.05).These results indicate that high level of dietary soy isoflavones(above 4 g kg-1) significantly depresses growth responses and FER of Japanese flounder.However,as the content of soy isoflavones in soybean meal is around 1 to 3 g kg-1,the adverse effects might be neglected when soybean products are used as a fish feed ingredient.

Consumption of soybean,soy foods,soy isoflavones and breast cancer incidence:Differences between Chinese women and women in Western countries and possible mechanisms

Breast cancer is one of the most lethal diseases world-wide.However,there is a large difference in breast cancer incidence among Caucasian,Hispanic,African and Asian(e.g.Chinese)women with Caucasian women being the highest and Asian women being the lowest.It has been suggested that the dietary factors may account for approximately 50%of the breast cancer.One of such dietary components which are typical to Asian but not Caucasian diet is soy foods.A number of epidemiological studies have suggested that increasing soy consumption could be related to the decreased risk of occurrence and/or mortality of breast cancer.In this review,we first described briefly different types of soy products and their nutritional functions and consumption.Then,we described briefly soybean isoflavones,i.e.genistein(GEN),daidzein,glycitein,and presented several lines of evidence to demonstrate the possible association of soy flavone food consumption with incidence and prognosis of breast cancer;finally,we summarized several possible molecular mechanisms,including the effects of GEN as an agonist of ER,epigenetic and genome-wide effects,activation of peroxisome proliferator-activated receptors,induction of apoptosis and stimulation of autophagy,involved in the chemo-preventive effects of GEN on breast cancer.©2013 Beijing Academy of Food Sciences.Production and hosting by Elsevier B.V.All rights reserved.

Soy isoflavone extracts stimulate the growth of nude mouse xenografts bearing estrogen-dependent human breast cancer cells(MCF-7)

We explored the effects of different lifetime exposures to soy isoflavone extracts on the growth of estrogen- dependent human breast cancer cells （MCF-7） implanted into athymic mice of different ovarian statuses. The athymic mice, ovariectomized or not, were implanted with MCF-7 cells. Mice were fed with low, moderate and high doses of soy isoflavone extract, at dietary concentrations of 6.25, 12.5 and 25 g/kg, in different reproductive models, respectively. The expression of ki-67 was detected by immunohistochemistry, pS2 expression in tumors was analyzed by real-time PCR. Estrogen level in the serum was measured by chemiluminescence enzyme im- munoassay. Total genistein and daidzein levels in serum and urine were determined by liquid chromatography- electrospray tandem mass spectrometry （LC-ES/MS/MS）. In Group A, on week 4, nude mice were exposed to different doses of soy iosflavone extracts. In Group B, the experimental diets were given to the nude mice follow- ing ovariectomy and tumor implantation. In both groups, 6.25 and 12.5 g/kg soy isoflavone extracts stimulated the growth of MCF-7 xenografts, increased pS2 expression, proliferation and estrogen level in serum. In both Group B （postmenopausal mouse model） and Group C （premenopausal mouse model）, soy isoflavone extracts at doses of 6.25 and 12.5 g/kg showed stimulatory effects on the growth of MCF-7 tumors. In conclusion, administration of soy isoflavone extracts at doses of 6.25 and 12.5 g/kg during adolescence or later in life stimulated tumor growth in both menopausal and postmenopausal mouse models.

Effects of soybean isoflavones on reproductive parameters in Chinese mini-pig boars

Background： Soybean isoflavones are structurally similar to mammalian estrogens and therefore may act as estrogen agonists or antagonists. However, it has not been determined if they have any negative effects on reproductive parameters in male livestock. Therefore, the objective of this study was to evaluate the effects of soybean isofiavones on male reproduction using Chinese mini-pig boars as a model. Fifty Xiang boars were randomly divided into five groups and fed diets containing 0, 125, 250, or 500 ppm soybean isoflavones or 0.5 ppm diethylstilbestrol for 60 days. Results： Dietary supplementation with 250 ppm of soy isoflavones markedly increased the testis index （P 〈 0.05）, fructose content （P 〈 0.05）, and o-glycosidase content in testicular tissue （P 〈 0.01）, as well as increased the number of viable germ cells （P 〈 0.01） and the level of Bcl-2 protein （P 〈 0.01）. However, 500 ppm of soybean isoflavones significantly reduced both testis and epididymis indexes （P 〈 0.0S） and lactate dehydrogenase levels （P 〈 0.01）, as well as reduced serum LH and testosterone levels （P 〈 0.05）. High levels of soybean isoflavones also increased malondialdehyde levels （P 〈 0.05）, as well as increased the numbers of early and late apoptotic germ cells （P 〈 0.01） and the level of Bax proteins （P 〈 0.05） in the testis. Conclusions： The results of this study indicate that consumption of soy isoflavones at dietary levels up to 250 ppm did not adversely affect reproductive parameters in Chinese mini-pig boars whereas higher levels of soy isoflavones may adversely affect male reproduction.

Effect of Soy Isoflavone Crude Extract Supplementation on High Fat Diet-induced Insulin Resistance in Ovariectomized Rats

Female Wister rats aged 8 weeks were randomly divided into sham operation group, ovariectomized （OVX） control group, and 20VX groups fed with soy isoflavone crude extract supplementation. The rats had free access to high fat diet and water for 9 weeks. No significant difference was found in body weight （BW）, total abdominal fat, food intake and food utilization rate between OVX control group and 20VX groups. However, the fasting blood glucose and blood lipid levels were significantly higher in 20VX groups than in OVX control group （P〈0.05）. Intraperitoneal glucose tolerance test （IGTI＂） showed that the area under AUC was smaller in 20VX groups than in OVX control group （P〈0.05）. These findings showed that soy isoflavone crude extract supplementation can improve glucose tolerance and prevent high fat diet-induced insulin resistance in ovariectomized rats.

Subchronic Toxicity Study on Soy Isoflavones in Rats

Objective To investigate the subchronic toxicity of soy isoflavones （SIF） in male rats. Method Fifty Sprague-Dawley rats were randomly divided into 5 groups, 10 rats per group. SIF were given to rats in different groups by gavage at dose of 0, 0.2, 0.5, 1.5, and 4.5 g/kg bw, respectively for 13 weeks. Clinical manifestations, body weight, and food consumption were observed weekly. At the end of the study, urinalysis, hematology, clinical chemistry, total testosterone, and follicle-stimulating hormone were tested, and histopathological examinations were performed. Results No mortality, ophthalmic abnormalities or treatment-related clinical signs were identified during the study. As compared with the control group, significantly lower body weights and food consumption were observed in 1.5 and 4.5 g/kg bw groups. In clinical chemistry tests, triglyceride was significantly decreased and high-density lipoprotein cholesterol was significantly increased in all SIF-treated groups. Total testosterone levels were significantly lower in 0.50, 1.50, and 4.5 g/kg bw dose groups than in the control group. Microscopic examination showed that the mammary glands exhibited hyperplasia and excreted latex in rats of the 4.5 g/kg bw group. No changes attributable to treatment of SIF in other parameters were found. Conclusion SIF at high dosages caused significant endocrine disruption in male rats. The no observed adverse effect level （NOAEL） of SIF to male rats in this study is considered to be 0.20 g/kg bw.

Urinary Profiles of Soy Isoflavone Metabolites in Women,Female Piglets and Female Rats Consuming Soy Diet

Objective: To investigate the urinary soy isoflavone metabolites from women, female piglets and rats fed with diet containing soy protein. Methods: Urinary samples from human and animals were collected after soy diet consumption. Identification for soy isoflavone metabolites in urine samples was processed using an Agilent Bruker LC Esquire ion trap system. Quantification of aglycone and conjugated soy isoflavone metabolites were also analyzed using a method published previously. Results: Identification studies showed that aglycones and conjugates of soy isoflavone metabolites were found in women and porcine samples. Interestingly, glucuronide conjugate of equol, besides glucuronide conjugates of genistein and daidzein, were found in rat urine. Glucuronide conjugate of equol was the major metabolite found in rat urine. A quantitative study showed that conjugated forms of isoflavones were more than 90% in woman urine, were between 80.5% and 84.5% in female porcine urine, and were less than 50% in female rat urine. Conclusion: Equol is the major metabolite found in female rat urine, but it is not found in woman or female porcine urine. Urinary profiles show that porcine model is more appropriate for mimicking human soy diet consuming studies.

Effects of Soy Isoflavones on the Sex Hormone Level and Pathological Changes in the Perimenopausal Syndrome Animal Model

[Objectives] To observe the effect of soy isoflavones on the perimenopausal syndrome model of female rats,and to find its mechanism,in order to provide experimental evidence for the clinical treatment of menopausal syndrome. [Methods]50 female SD rats were randomly divided into five groups,with 10 rats in each group,respectively,for the normal control group,sham operation group,model group,diethylstilbestrol group,soy isoflavone treated group,except the normal control group and sham operation group,the other groups were ovariectomized rats,the formation model of perimenopausal rats treated with normal saline,diethylstilbestrol,soy isoflavone by gavage,normal control group and sham operation group were given the same dose of normal saline and soy isoflavone by gavage. After 6 weeks of continuous treatment,abdominal aorta was taken blood,the serum was isolated,and radioimmunoassay method to measure E_2( Eestradiol),P( Progesterone),T( Testosterone). And removal of the pituitary gland,uterine and adrenal prepared pathological section,experimental effect was observed by light microscopy,using immunohistochemical method to observe the brain pituitary FSH( Follicle-Stimulating Hormone) and LH( Luteinizing Hormone) levels. [Results] Radiation immune analysis results showed that soy isoflavone could significantly improve serum E_2 level in ovariectomized rats,compared with the model group,the statistical analysis showed significant difference( P < 0. 05),but the serum P and T level had little effect. The pathological results showed that( i) uterus: the uterine wall and endometrial thickness of soy isoflavone group was between that of model group and sham operation group,the surface epithelium was columnar,glands increased;( ii) pituitary gland: soy isoflavone ovariectomized group cells were between model group and normal group;( iii) adrenal gland: soy isoflavone group adrenal tissue did not change significantly. Immunohistochemical results showed that soy isoflavone group pituitary tissues of FSH and LH cells compared with the model group decreased significantly. [Conclusions] The soy isoflavones could make the uterus wall and endometria of perimenopausal syndrome animal model thicken,improve the serum level of E_2 in ovariectomized rats,and decrease the level of FSH and LH,but had little effect on the adrenal tissues,level of T and P.

Urine Metabonomic Analysis of Interventions Effect of Soy Isoflavones on Rats Exposed to Di-(2-ethylhexyl) Phthalate

Objective Di-(2-ethylhexyl) phthalate(DEHP) is a ubiquitous environmental contaminant.As an endocrine disruptor,it seriously threatens human health and ecological environmental safety.This study examines the impact of intervention with soybean isoflavones(SIF) on DEHP-induced toxicity using a metabonomics approach.Methods Rats were randomly divided into control(H),SIF-treated(A,86 mg/kg body weight),DEHP-treated(B,68 mg/kg),and SIF plus DEHP-treated(D) groups.Rats were given SIF and DEHP daily through diet and gavage,respectively.After 30 d of treatment,rat urine was tested using UPLC/MS with multivariate analysis.Metabolic changes were also evaluated using biochemical assays.Results Metabolomics analyses revealed that p-cresol glucuronide,methyl hippuric acid,N1-methyl-2-pyridone-5-carboxamide,lysophosphatidycholine [18:2(9 Z,12 Z)] {lyso PC [18:2(9 Z,12 Z)]},lyso PC(16:0),xanthosine,undecanedioic acid,and N6-acetyl-l-lysine were present at significantly different levels in control and treatment groups.Conclusion SIF supplementation partially protects rats from DEHP-induced metabolic abnormalities by regulating fatty acid metabolism,antioxidant defense system,amino acid metabolism,and is also involved in the protection of mitochondria.

Molecular docking studies of human MCT8 protein with soy isoflavones in Allan-Herndon-Dudley syndrome(AHDS)

Monocarboxylate transporter-8 （MCT8） is a specific thyroid hormone transporter, essential for the uptake of thyroid hormone into target tissues. Mutations in the MCT8 gene have been identified as the cause of Allan-Herndon-Dudley syndrome （AHDS）. It has been reported that soy isoflavones influence thyroid hormone system and can interact with thyroid hormone transporter proteins. Therefore, the present study aimed to find out whether soy isoflavones （genistein, daidzein and glycitein） can be used as a natural inhibitor to target MCT8 in AHDS. Docking studies were performed for soy isoflavones in order to evaluate their binding affinity to MCT8 protein using AutoDock4 （version 4.2.6） and AutoDock Vina. After docking, the ligands were ranked according to their binding energy and the best lead compound was selected based on the least binding energy. The docking results indicated that daidzein possesses the lowest binding energy against MCT8. Moreover, it was found that the residues PRO-338, HIS-341, and GLU-348 were involved in hydrogen bond interactions with genistein and daidzein. This study suggests that daidzein is a promising natural inhibitor to target MCT8 in AHDS.

Effect of daily supplementation of soy isoflavones on hot flashes and night sweats in African menopausal women

The aim of this study was to evaluate the effectiveness of a pharmaceutical grade isoflavone supplement (Inoclim?) 40 mg per capsule of soy extract rich in daidzin and genistin) on the number of hot flashes and night sweats in menopausal African women. This open, prospective, multicenter study involved 140 menopausal women with climacteric symptoms (i.e., a minimum of five hot flashes and/or moderate to severe night sweats per day). These patients received a daily 40-mg supplement of soy isoflavone contained in an Inoclim? capsule (Laboratoire Innotech International, France). The dose was increased to two capsules per day when there were more than five hot flashes or when the women could not sleep because of night sweats. The patients were followed up over a 4-month period and data were analyzed using EPI-InfoTM version 3.5.1. The outcome measure was fewer hot flashes and night sweats. The mean daily number of episodes of hot flashes was 5.7 at baseline and 1.8 at week 16, corresponding to a decrease of 68.4% (n = 93 patients at baseline and n = 66 at 16 weeks). The mean number of daily episodes of night sweats was 3.7 at baseline and 0.8 at week 16, corresponding to a decrease of 78.4% (n = 127 patients in the first week and n = 73 at 16 weeks). Over 80% of patients took a single one 40 mg capsule per day. The percentage of patients who adhered to the prescription was more than 95% during the 4-month follow-up period. These results confirm the effectiveness of a pharmaceutical grade isoflavone supplement (40 mg, rich in genistin and daidzin) on vasomotor symptoms in menopausal women.

SIF干预肥胖大鼠下丘脑瘦素介导JAK/STAT信号通路的研究

通过观察SIF对肥胖大鼠下丘脑中瘦素介导的信号通路蛋白表达的影响,探讨SIF对肥胖大鼠的干预机制。采用高脂饲料饲喂大鼠,建立肥胖动物模型,并将肥胖大鼠分为4组,分别灌胃SIF,剂量为:对照组(Ⅰ组)0 mg·kg^(–1)、低剂量组(Ⅱ组)50 mg·kg^(–1)、中剂量组(Ⅲ组)150 mg·kg^(–1)、高剂量组(Ⅳ组)450 mg·kg^(–1),并设置正常大鼠基础组(Ⅴ组),饲喂基础饲料,并灌胃给予SIF处理等体积的羧甲基纤维素钠,连续4周。采用HE染色法观察下丘脑组织学结构变化,免疫组织化学SABC法检测下丘脑中瘦素介导的JAK/STAT信号转导通路蛋白OB-Rb(瘦素受体长型),JAK2(内源性酪氨酸蛋白激酶2),p-STAT3(磷酸化的信号转导与转录激活子3),SOCS3(细胞因子信号3抑制因子),NPY(神经肽Y)的表达水平。结果显示:高剂量组和基础组OB-Rb,JAK2,p-STAT3的阳性表达水平显著高于其他组(P<0.05),且前述蛋白均有随SIF的剂量增加而表达增多趋势。高剂量组和基础组的SOCS3和NPY表达水平显著较其他组低(P<0.05),但NPY在背内侧核和室旁核的表达随SIF的剂量增加而增多。OB-Rb,JAK2,p-STAT3,SOCS3和NPY均在下丘脑广泛表达,并随SIF的剂量增加而变化,提示SIF对瘦素介导的信号通路有一定作用并与机体能量的调节密切相关;SIF通过干预大鼠下丘脑瘦素JAK/STAT信号通路具有减重作用,并呈剂量依赖性。

大豆异黄酮对安格斯肉牛免疫性能、生殖激素水平和血清代谢物的影响

本试验旨在探究饲粮添加不同水平大豆异黄酮(SIF)对安格斯肉牛免疫性能、生殖激素水平和血清代谢物的影响。试验选取40头体重(396.87±35.42)kg、2~3胎次的健康安格斯母牛,随机分为4组,每组10头。对照组(CG组)饲喂基础饲粮,试验组分别在基础饲粮的基础上添加10(SIF-10组)、20(SIF-20组)和40 mg/kg(SIF-40组)SIF。预试期7 d,正试期40 d。饲养试验结束后采集血液,检测血清生化指标以及血清免疫因子和生殖激素含量,并基于超高效液相色谱-串联质谱(UPLC-MS/MS)非靶向代谢组学技术分析SIF对血清代谢物的影响。结果表明:1)与CG组相比,SIF-10组和SIF-20组血清总蛋白(TP)含量显著提高(P<0.05),血清谷丙转氨酶(ALT)活性显著降低(P<0.05);SIF-20组血清球蛋白(GLB)含量显著提高(P<0.05);SIF-40组血清TP和GLB含量极显著提高(P<0.01),血清谷草转氨酶(AST)和ALT活性极显著降低(P<0.01)。2)与CG组相比,SIF-10组和SIF-20组血清免疫球蛋白A(IgA)和免疫球蛋白G(IgG)含量显著提高(P<0.05);SIF-20组血清干扰素-γ(IFN-γ)含量显著提高(P<0.05),血清白细胞介素-4(IL-4)含量极显著提高(P<0.01);SIF-40组血清IgA、IgG、免疫球蛋白M(IgM)、IFN-γ、白细胞介素-2(IL-2)和IL-4含量均极显著提高(P<0.01)。3)与CG组相比,SIF-40组血清孕酮、雌二醇、促卵泡激素和促黄体生成素含量均极显著提高(P<0.01)。4)CG组和SIF-40组之间共筛选出346种血清差异代谢物[P<0.05、变量投影重要度(VIP)≥1、差异倍数(FC)>2.0或FC<0.5],其中,相对于CG组,SIF-40组163种代谢物上调、183种代谢物下调。选取VIP值前20的代谢差异物(14种上调、6种下调)进行通路富集,发现甘氨酸、丝氨酸和苏氨酸代谢、苯丙氨酸代谢、泛酸和辅酶A生物合成、赖氨酸降解、色氨酸代谢、丁酸代谢、叶酸生物合成以及柠檬酸循环等8个代谢通路发生显著变化。综上所述,饲粮添加一定水平SIF能够提高安格斯肉牛母牛免疫性能、生殖激素水平以及代谢水平,且以添加40 mg/kg为宜。

Effects of soy components on blood and liver lipids in rats fed high-cholesterol diets

AIM: To assess the effects of soy protein, isoflavone, and saponin on liver and blood lipid in rats that consumed high-cholesterol diets.METHODS: High-cholesterol diets (1%) with or without soy material were fed to 6-wk-old male Sprague-Dawley rats for 8 wk. Blood lipids, liver lipids, glutamic oxaloacetic transaminase (GOT), and glutamic pyruvic transaminase (GPT) levels were measured. The in vitro bile acid-binding ability of soy materials was analyzed.RESULTS: The results of in vitro studies showed that soy protein isolate had a significantly higher bile acid-binding ability (8.4±0.8%) than soy saponin (3.1±0.7%) and isoflavone (1.3±0.4%, P＜0.05). On the other hand, at the end of the experimental period, rats that consumed soy protein diets had lower GOT and GPT levels than rats that consumed casein under high-cholesterol diets.Rats that consumed soy protein also had lower total cholesterol (TC) levels in the liver than those that consumed casein under high-cholesterol diets. Rats that consumed the soy protein diet containing both saponin and isoflavone had lower hepatic TC level than those that consumed the soy protein diet without isoflavone alone.The effect of different types of proteins on triglyceride was not significant.CONCLUSION: Consumption of soy provided benefits to control lipid levels under high-cholesterol dieting conditions in this rat model of hypercholesterolemia. The major component that reduced hepatic TC was not saponin, but possibly isoflavone.

The development of soy sauce from organic soy bean

Soy sauce by a high salt liquid-state fermentation process was prepared using the organic soy beans as raw material. Beidahuang organic soy bean was selected among different raw materials. Here, the best technique was determined. Firstly, the organic soy beans were soaked for 7 hours under 121℃, steamed for 15 min and mixed with the fried wheat (5:5, w/w). After inoculated with Aspergillus oryzae 3.042 (0.3%, w/w) and cultured for 36 hours, the koji was obtained. When the brine (2:1, w/w) was added, fermentation started. At the end of the fermentation, isoflavone content of organic soy sauce was 0.22 mg· g-1 higher than those in the non- organic soy beans. In addition, compared to the control there were a higher unsaturated fatty acids content, the linoleic acid content in crude fat of 51.61% and γ-linolenic acid content in crude fat of 0.55%.

异黄酮与β-伴大豆球蛋白的相互作用及其对蛋白结构和潜在致敏性的影响

探究异黄酮和β-伴大豆球蛋白(β-conglycinin,BCG)的相互作用机理及其对复合物结构和潜在致敏性的影响。利用荧光光谱、圆二色光谱分析2种大豆异黄酮(染料木素(genistein,Gen)、大豆苷元(daidzein,Dai))与BCG相互作用的猝灭类型、结合位点数、作用力类型和蛋白二级结构含量的变化,表征不同条件下制备的异黄酮-BCG复合物的结构,并利用酶联免疫吸附测定(enzyme linked immunosorbent assay,ELISA)与消化产物免疫印迹检测其潜在致敏性。结果表明:活性异黄酮(Gen/Dai)对BCG的猝灭为静态猝灭,且相互作用力以疏水相互作用为主,结合位点数均接近1;并且与异黄酮相互作用诱导了BCG氨基酸微环境的极性增加,使蛋白肽链伸展,结构更为松散;ELISA与消化产物免疫印迹结果显示,与异黄酮结合后蛋白的潜在致敏性增强。本研究有助于科学认识异黄酮在食品复杂基质体系中对过敏蛋白致敏性影响机制,对其抗过敏的深度开发利用具有重要意义。

饲料中大豆异黄酮检测方法的建立

[目的]建立用于检测饲料中大豆提取物的高效液相色谱方法(HPLC),为大豆异黄酮在畜牧业的合理使用提供支持。[方法]通过查阅文献,采用HPLC色谱技术,样品经甲醇溶液超声提取后,以乙腈-0.1%醋酸水为流动相梯度洗脱,260 nm波长检测。[结果]建立的HPLC检测方法,线性范围为0.2~20μg/mL,定量限可达0.197μg/mL,以2、15μg/mL的质量浓度进行添加回收,添加回收率为97.45%~102.54%。[结论]按建立的HPLC方法检测5%纯度的大豆异黄酮,可检测6种组分的含量分别为:大豆苷1.13%、大豆黄苷0.22%、染料木苷2.79%、大豆苷元0.55%、大豆黄素0.06%和染料木素0.29%,总黄酮含量为5.04%。

饲粮中添加大豆异黄酮对安格斯肉牛生产及繁殖性能的影响

【目的】研究饲粮中添加不同水平大豆异黄酮对安格斯肉牛生长性能、血清生化指标、抗氧化能力、免疫性能及繁殖激素的影响,探讨大豆异黄酮在肉牛生产实践中的适宜添加量。【方法】选取40头体重相近、2~3胎次且健康的安格斯母牛,随机分为4组,每组10头。对照组牛饲喂基础饲粮,试验Ⅰ、Ⅱ、Ⅲ组牛分别在基础饲粮中添加10、20和40 mg/kg大豆异黄酮。试验始末对牛进行称重,记录每日采食量,计算平均日采食量(ADFI)、平均日增重(ADG)及料重比(F/G);第40天时,采集血液检测血清生化、抗氧化、免疫指标及繁殖激素水平。【结果】与对照组相比,(1)添加大豆异黄酮对安格斯肉牛ADFI、ADG及F/G均无显著影响(P>0.05)。(2)试验Ⅰ、Ⅱ组牛血清中总蛋白含量显著升高(P<0.05),谷丙转氨酶活性显著降低(P<0.05);试验Ⅲ组牛血清中总蛋白和球蛋白含量极显著升高(P<0.01),谷草转氨酶和谷丙转氨酶活性极显著降低(P<0.01);试验Ⅲ组牛血清中免疫球蛋白(IgA、IgM、IgG)及γ-干扰素水平极显著或显著升高(P<0.01;P<0.05)。(3)试验Ⅱ组牛血清中总抗氧化能力(T-AOC)及谷胱甘肽过氧化酶(GSH-Px)活性均极显著升高(P<0.01);试验Ⅲ组牛血清中T-AOC、GSH-Px及超氧化物歧化酶水平均极显著升高(P<0.01),丙二醛含量极显著降低(P<0.01)。(4)试验Ⅱ组牛血清中雌二醇水平显著升高(P<0.05);试验Ⅲ组牛血清中孕酮、雌二醇、促卵泡激素及促黄体生成素水平均极显著升高(P<0.01)。【结论】饲粮中添加大豆异黄酮可有效提高安格斯肉牛免疫功能和繁殖机能,其中40 mg/kg大豆异黄酮添加量效果最佳。