大豆蛋白对胆固醇作用的研究进展

大量文献表明，大豆蛋白可以降低实验动物和人血液中胆固醇的含量，但其机理尚不完全清楚。为此，本文从胆固醇吸收、代谢、排泄及其对内分泌的影响等几方面详细地综述了膳食中大豆蛋白对胆固醇代谢的影响，并对其可能的作用机理加以阐述。     

大豆异黄酮对动脉粥样硬化去卵巢大鼠ATP结合盒A1基因表达的影响

目的 探讨不同剂量大豆异黄酮(SI)对动脉粥样硬化去卵巢SD大鼠ATP结合盒A1(ATP binding cassette A1,ABCA1)表达的影响.方法 50只12周龄SPF级雌性SD大鼠,经普通饲料适应喂养1周后,行卵巢切除术.按体重分层随机抽样,选取10只作为基础对照组(A组),全程喂基础饲料;另40只喂高脂饲料,4周后再按血脂水平分层随机分为4组,每组10只,分别为高脂模型组(B组),继续喂高脂饲料;低剂量SI组(高脂饲料+30 mg/kg SI,C组);中剂量SI组(高脂饲料+90 mg/kg SI,D组);高剂量SI组(高脂饲料+270 mg/kg SI,E组).分组后继续喂22周,处死动物,观察主动脉形态学变化,real-time PCR检测主动脉血管壁ABCA1基因的表达,Western blotting测定ABCA1蛋白在肝脏、主动脉血管壁以及小肠组织的表达情况.结果 各组血脂水平:A、B、C、D、E组总胆固醇水平分别为(6.82±0.22)、(15.73±1.51)、(10.77±1.12)、(9.95±1.18)、(9.11±1.12)mmol/L(F=72.882,P<0.01);甘油三酯水平分别为(2.49±0.24)、(0.78±0.13)、(0.39±0.08)、(0.29±0.09)、(0.24±0.09)mmol/L(F=378.515,P<0.01);低密度脂蛋白胆固醇水平分别为(1.29±0.08)、(14.76±1.23)、(8.18±0.80)、(7.85±0.72)、(7.16±0.64)mmol/L(F=320.936,P<0.01);高密度脂蛋白胆固醇水平分别为(1.94±0.18)、(1.04±0.10)、(1.55±0.14)、(1.88±0.17)、(2.11±0.22)mmol/L(F=49.450,P<0.01).各组ABCA1蛋白在小肠、肝脏、血管壁内表达水平:A、B、C、E组ABCA1蛋白在小肠内表达水平(灰度值)为96.577±9.743、5.218±2.048、18.060±5.179、54.725±8.960(F=172.272,P<0.01);在肝脏内表达水平为13.657±2.397、1.361±0.266、7.069±2.264、11.793±2.515(F=37.383,P<0.01);在血管壁中表达水平为6.756±1.310、0.027±0.006、0.035±0.002、7.479±1.520(F=91.999,P<0.01).B组主动脉可见动脉粥样硬化斑块,而饲料中添加SI能有效避免动脉粥样硬化斑块的形成.结论 SI可能是通过降血脂,提高ABCA1表达水平发挥其抗动脉粥样硬化功能.     

Development of Bean pod mottle virus-based vectors for stable protein expression and sequence-specific virus-induced gene silencing in soybean

Plant virus-based vectors provide valuable tools for expression of foreign proteins in plants and for gene function studies. None of the presently available virus vectors is suitable for use in soybean. In the present study, we produced Bean pod mottle virus (BPMV)-based vectors that are appropriate for gene expression and virus-induced gene silencing (VIGS) in soybean. The genes of interest were inserted into the RNA2-encoded polyprotein open reading frame between the movement protein (MP) and the large coat protein (L-CP) coding regions. Additional proteinase cleavage sites were created to flank the foreign protein by duplicating the MP/L-CP cleavage site. To minimize the chances of homologous recombination and thus insert instability, we took advantage of the genetic code degeneracy and altered the nucleotide sequence of the duplicated regions without affecting amino acid sequences. The recombinant BPMV constructs were stable following several serial passages in soybean and relatively high levels of protein expression were attained. Successful expression of several proteins with different biological activities was demonstrated from the BPMV vector. These included the reporter proteins GFP and DsRed, phosphinothricin acetyltransferase (encoded by the herbicide resistance bar gene), and the RNA silencing suppressors encoded by Tomato bushy stunt virus, Turnip crinkle virus, Tobacco etch virus, and Soybean mosaic virus. The possible use of BPMV as a VIGS vector to study gene function in soybean was also demonstrated with the phytoene desaturase gene. Our results suggest that the BPMV-based vectors are suitable for expression of foreign proteins in soybean and for functional genomics applications.     

不同职业围绝经期妇女摄入大豆类及其制品情况调查

目的 调查不同职业围绝经期女性大豆类及其制品膳食摄入情况,为指导合理摄取天然植物雌激素—大豆异黄酮,提高女性围绝经期健康水平提供依据.方法 自行设计调查问卷调查465名来自广州市属三家医疗机构和公安系统的围绝经期妇女关于大豆类及其制品相关营养知识及摄入情况,分析两组差异性.结果 医护组女性掌握大豆类食物相关营养知识优于干警组女性,日常膳食主动摄入大豆类及其制品频率多于女干警组,差异有统计学意义(P＜0.05);医护组女性主要选择新鲜制作大豆类食物软豆腐、自家现磨豆浆、现榨豆浆等,干警组女性选择豆制品如豆干、腐竹、豆腐花等较多.结论 建议加强对干警组女性人群营养教育,增加大豆类及其制品相关营养知识,改善天然植物雌激素—大豆异黄酮摄入情况,提高围绝经期健康水平.     

Validation of soy isoflavone intake and its health effects: a review of the development of exposure biomarkers

BACKGROUND/OBJECTIVESIt is difficult to consistently demonstrate the health effects of soy isoflavones owing to the multitude of factors contributing to their bioavailability. To accurately verify these health effects, dietary isoflavone intake should be measured using a biologically active dose rather than an intake dose. This concept has been expanded to the development of new exposure biomarkers in nutrition research. This review aims to provide an overview of the development of exposure biomarkers and suggest a novel research strategy for identifying the health effects of soy isoflavone intake.MATERIALS/METHODSWe cover recent studies on the health effects of soy isoflavones focusing on isoflavone metabolites as exposure biomarkers.RESULTSCompared to non-fermented soy foods, fermented soy foods cause an increased concentration of isoflavones in the biofluid immediately following ingestion. The correlation between exposure biomarkers in blood and urine and the food frequency questionnaire was slightly lower than that of corresponding 24-h dietary recalls. Urinary and blood isoflavone levels did not show a consistent association with chronic disease and cancer risk.CONCLUSIONIt is crucial to understand the variable bioavailabilities of soy isoflavones, which may affect evaluations of soy isoflavone intake in health and disease. Further studies on the development of valid exposure biomarkers are needed to thoroughly investigate the health effects of isoflavone.     

大豆B0wman—Birk型胰蛋白酶抑制剂（BBI）研究进展

该文在阐述Bowman—Birk型胰蛋白酶抑制剂(BBI)的分子结构、生理活性及吸收分布的基础上，系统介绍了BBI在抗癌活性和辐射保护功能上取得的研究进展。目前对于BBI抗癌活性的研究已进入到临床试验的阶段，并已研制出多种有效的结合剂型。     

大豆磷脂脂质体对心肌缺血－再灌注家兔左心室功能和梗塞范围的影响

膜磷脂降解、丢失是心肌缺血－再灌注损伤的重要发病环节。本实验观察了静脉滴注大豆磷脂脂质体（１１０ｍｇ磷脂／ｋｇ／次×２次）对心肌缺血（４５ｍｉｎ）－再灌注（２３ｈ１５ｍｉｎ）家兔左心室的舒缩功能和梗塞范围的影响。结果发现经处理的动物的左室±ｄｐ／ｄｔｍａｘ均明显大于对照组，梗塞范围明显小于对照组（Ｐ＜０．０５，Ｐ＜０．０１）。提示大豆磷脂脂质体能明显改善在体缺血－再灌注心肌的舒缩功能，缩小梗塞范围。     

Soy Product Intake and Serum Isoflavonoid and Estradiol Concentrations in Relation to Bone Mineral Density in Postmenopausal Japanese Women

To evaluate soy intake and serum concentrations of estradiol and isoflavonoids and their relationship to bone mineral density (BMD) and serum bone-specific alkaline phosphatase (bone ALP) activity, we conducted a cross-sectional study of 87 postmenopausal Japanese women. Soy product and isoflavone intake from soy products and intake of nutrients were assessed with a semiquantitative food-frequency questionnaire. BMD (mg/cm²) was measured by single-energy X-ray absorptiometry at the site of the calcaneus. Serum estradiol (E₂) and the sex hormone-binding globulin (SHBG) were measured by radioimmunoassay. Serum genistein and daidzein concentrations were measured by a high-performance liquid chromatography MS/MS method. A statistically significant correlation was observed between the ratio of E₂ to SHBG and BMD (Spearman r = 0.38, p = 0.0003) after controlling for age, body mass index, smoking status, age at menarche, and intake of vegetable fat, vitamin C and salt. Soy product and isoflavone intake and serum isoflavones were not significantly correlated with BMD after controlling for the covariates. Serum ALP was not significantly correlated with soy product and isoflavone intake, the E₂/SHBG ratio or serum isoflavones. The present study supports the association of BMD with serum estradiol; however, it does not support the association of BMD with soy or isoflavone intake or serum isoflavone levels. Received: 13 August 2001 / Accepted: 30 October 2001     

大豆异黄酮对非酒精性脂肪肝大鼠肝脏脂代谢的影响

目的 研究大豆异黄酮对非酒精性脂肪肝(NAFLD)大鼠肝脏脂质、血脂、抗氧化指标及肝脏脂肪代谢相关因子的影响.方法 将36只雄性SD大鼠用随机数字表法按体重分层随机分为正常对照组、NAFLD模型对照组、大豆异黄酮低剂量组(10 mg/kg)及高剂量组(20 mg/kg),每组9只.正常对照组采用D12450B饲料(10%脂肪热能),模型对照组和大豆异黄酮干预组采用D12492饲料(60%脂肪热能),喂养12周后,检测各组大鼠肝脏脂质、血脂和抗氧化指标的变化,Western blotting检测大鼠肝组织中固醇调节原件结合蛋白-1c(SREBP-1c)、脂肪酸合成酶(FAS)和过氧化物酶体增殖物激活受体α(PPARα)的蛋白表达.结果 正常对照组、NAFLD模型对照组、大豆异黄酮低剂量组、高剂量组肝脏甘油三酯(TG)分别为(8.11±4.13)、(57.06±16.95)、(31.26±10.48)、(31.38±13.25)mmol/mg蛋白(F=22.569,P＜0.01);肝脏游离脂肪酸(FFA)分别为(0.030±0.007)、(0.042±0.009)、(0.038±0.009)、(0.032±0.005)μmol/mg蛋白(F=4.857,P＜0.01);肝脏超氧化物歧化酶(SOD)活性分别为(502.29±23.71)、(201.83±16.99)、(228.93±21.71)、(238.08±15.96)U/mg蛋白(F=9.555,P＜0.01);肝脏丙二醛(MDA)含量分别为(1.29±0.29)、(2.85±0.73)、(2.07±0.49)、(2.03±0.37)nmol/mg蛋白(F=13.449,P＜0.01);肝脏SREBP-1c蛋白表达分别为0.45±0.16、1.42±0.30、1.02±0.31、0.47±0.27(F=24.515,P＜0.01);FAS蛋白表达分别为0.27±0.08、1.97±0.47、1.35±0.30、0.49±0.12(F=60.361,P＜0.01);PPARα蛋白表达分别为2.03±0.56、0.41±0.17、0.81±0.27、0.66±0.16(F=37.97,P＜0.01).结论大豆异黄酮可能通过抑制SREBP-1 c、激活PPARα的表达来减少肝脏脂质沉积,增加抗氧化能力.

Abstract：

Objective To study the effects of soybean isoflavone on liver lipid,serum lipid,antioxidant index and hepatic lipid metabolism associated factors in nonalcoholic fatty liver rats.Methods Thirty-six male rats(SD)were randomly divided into four groups by weight: normal control group,nonalcoholic fatty liver disease(NAFLD) model control group,low-dose isoflavone treatment group (10 mg/kg)and high-dose isoflavone group(20 mg/kg),9 rats in each group.Normal control rats were fed with D12450B(10% fat energy),model control and isoflavone intervention rats were fed with D12492(60%fat energy).Twelve weeks later,liver lipid,serum lipid and antioxidant index were observed.Liver sterol regulatory element binding protein-1 c(SREBP-1 c),fatty acid synthase(FAS)and Peroxisome proliferators activated receptor alpha(PPAR alpha)were detected by western blotting.Results Liver triglyceride(TG)in normal control group,NAFLD model control group,low-dose isoflavone group and high-dose isoflavone group were(8.11 ± 4.13),(57.06 ± 16.95),(31.26 ± 10.48),(31.38 ± 13.25)mmol/mg protein,respectively(F = 22.569,P ＜0.01); liver free fatty acid(FFA)were(0.030 ± 0.007),(0.042 ± 0.009),(0.038 ± 0.009),(0.032 ± 0.005)μmol/mg protein,respectively(F = 4.857,P ＜0.01); liver superoxide dismutase(SOD)activity were(502.29 ± 23.71),(201.83 ± 16.99),(228.93 ± 21.71),(238.08 ±15.96)U/mg protein,respectively(F = 9.555,P ＜0.01); liver malondialdehyde(MDA)were(1.29 ±0.29),(2.85 ± 0.73),(2.07 ± 0.49),(2.03 ± 0.37)nmol/mg protein,respectively(F = 13.449,P ＜0.01);SREBP-1 c protein expression were 0.45 ± 0.16,1.42 ± 0.30,1.02 ± 0.31,0.47 ± 0.27,respectively (F=24.515,P＜0.01);FAS protein expression were 0.27 ±0.08,1.97 ±0.47,1.35-0.30,0.49 ±0.12,respectively(F = 60.361,P ＜0.01); PPARα protein expression were 2.03 ± 0.56,0.41 ± 0.17,0.81 ±0.27,0.66±0.16,respectively(F=37.97,P＜0.01).Conclusion Soy isoflavone can reduce the hepatic lipid deposition and increase antioxidant capacity,the mechanism may be related to inhibition of SREBP-1c and activation of PPARα expression in liver.     

Changes of phytochemical constituents (isoflavones, flavanols, and phenolic acids) during cheonggukjang soybeans fermentation using potential probiotics Bacillus subtilis CS90

A potential probiotics Bacillus subtilis CS90 was isolated from Korean soybean paste (doenjang). Biotransformation of phytochemical contents, isoflavones, flavanols, and phenolic acids, during the fermentation of soybean fermented food cheonggukjang by a potential probiotics B. subtilis CS90 was investigated. The levels of isoflavone aglycones, flavanols, and gallic acid increased, while the β-glucosidase and esterase activities, isoflavone glycosides (except for acetylglycosides), and flavanol gallates contents decreased. Total isoflavone content slightly decreased after 60 h of fermentation, while total flavanol and phenolic acid content increased. The highest levels of daidzein (aglycone type) and acetyldaidzin (glycoside type) were recorded after 48 h of fermentation. However, the total contents of glycosides, manolylglycosides, and flavanol-gallates decreased by about 80, 90, and 70% during 60 h of fermenting cooked soybeans. In addition, the contents of total phenolic increased markedly from 253 mg/kg to 9414 mg/kg while the DPPH radical scavenging activity increased from 53.6 to 93.9% during this fermentation.