Alfalfa Phytoestrogen Content: Impact of Plant Maturity and Herbage Components

Legumes contain a range of non‐nutritional phytochemicals that may have health‐promoting effects in humans. In this study, we determined the concentrations of four phytoestrogens (coumestrol, apigenin, luteolin and quercetin) in field‐grown alfalfa (Medicago sativa L.). Differences between plants of different stages of maturity, between plant parts, and different canopy segments were assessed. The concentration of individual phytoestrogen in whole herbage varied between 15 and 225 μg g^?1 dry matter (DM) and was strongly affected by stage of maturity. Coumestrol and apigenin concentrations were highest at early vegetative stages, luteolin and quercetin at early vegetative and late flowering stages. All phytoestrogens were found in lowest concentrations at the early flowering stage (average 68 μg g^?1 DM); stage at which alfalfa is usually harvested when used as a forage source for animals. At vegetative stages, apigenin was the predominant phytoestrogen in herbage followed by coumestrol, the reverse being observed upon initiation of flowering; luteolin and quercetin were found at all stages in similarly lower concentrations. Concentrations of luteolin, quercetin and apigenin were 225, 410 and 690 % greater, respectively, in flowers than in leaves or stems; coumestrol concentration was similar between plant parts. In flowers and stems the predominant phytoestrogens were apigenin and quercetin, followed by coumestrol and luteolin. Similar concentrations (average 26 μg g^?1 DM) of each of the four phytoestrogens were found in leaves. Concentrations through the herbage canopy varied and were greatest at >60 cm from the soil surface for apigenin and coumestrol, but greatest at >60 and 0–20 cm for quercetin and at 0–20 cm for luteolin. The results suggest that if alfalfa is to be used as a source of phytoestrogens and is harvested for the production of herbal supplements or nutraceuticals, management will need to be adapted.     

Effect of Two Kinds of Phytoestrogens on Milk Composition,Blood Biochemical Index and Antioxidant Capacity of Dairy Cows

This experiment was conducted to investigate the effect of feeding phytoestrogens on milk composition, blood biochemical index and antioxidant capacity of dairy cows.A total of 40 Holstein cows were selected and randomly divided into 4 groups by health, age and lactation stage. The cows in control group was fed total mixed rations(TMR), and the other in 3 trial groups were fed TMR supplemented with 2.5 g dainzein(group Ⅰ), 35 g formononetin (group Ⅱ), 1.25 g dainzein and 17.5 g formononetin (group Ⅲ), respectively. The total duration of the trial was 127 d, the first 7 d of the trial was the preliminary period and the formal trial lasted for 120 d. The milk samples were collected in the trial of 0, 30, 60, 90, 120 d, respectively, and determination of milk composition. The blood samples were collected by jugular vein in the trial, and plasma was separated by 15 min, 3 500 r/min centrifugation, and saved at －20 ℃ for later use. The result showed as follows: Compared with the control group, the milk yield and milk protein yield in groups Ⅰ and Ⅲ were significantly increased (P< 0.05),the lactose yield in groups Ⅰ,Ⅱ and Ⅲ were significantly increased (P< 0.05), the T-AOC activity of blood in group Ⅲ was significantly increased (P< 0.05), the GSH-Px activity of blood in groups Ⅱ and Ⅲ were significantly increased (P< 0.05), the MDA activity of blood in groups Ⅰ and Ⅱ were significantly decreased (P< 0.05), the milk fat yield,lactose rate and TP, ALB, GLB of blood were not significantly increased (P> 0.05),the CAT, SOD activity of blood in trail groups had a upward trent. It was concluded that feeding phytoestrogens could enhance the milk yield, milk protein yield, lactose yield, the body's antioxidant capacity and immune function of Holstein cows.     

添喂两种植物雌激素对奶牛乳成分、血液生化指标和抗氧化性能的影响

试验旨在研究日粮中添喂两种植物雌激素及其组合物对奶牛乳成分、血液生化指标和抗氧化性能的影响。选取健康、年龄及泌乳期相近的40头荷斯坦奶牛,随机分为4组：1个对照组、3个试验组,每组10头。对照组饲喂全混合日粮,试验组在饲喂全混合日粮的基础上添加2.5 g大豆黄酮（试验Ⅰ组）、35 g芒柄花素（试验Ⅱ组）、1.25 g大豆黄酮和17.5 g芒柄花素（试验Ⅲ组）。预试期7 d,正试期120 d。分别于试验的第0、30、60、90、120天采集乳样,测定乳成分;颈静脉采集血液样品,3 500 r/min离心15 min,分离血浆,－20 ℃保存备用。结果表明,与对照组相比,试验Ⅰ、Ⅲ组产奶量、乳蛋白产量均显著提高（P< 0.05）;试验Ⅰ、Ⅱ、Ⅲ组乳糖产量显著提高（P< 0.05）;试验Ⅲ组T-AOC显著提高（P< 0.05）;试验Ⅱ、Ⅲ组GSH-Px活性显著提高（P< 0.05）;试验Ⅰ、Ⅱ组MDA含量极显著降低（P< 0.05）;乳脂产量、乳糖率及TP、ALB、GLB含量均无显著差异（P> 0.05）;CAT、SOD活性均有一定程度的提高。由此可见,日粮中添喂两种植物雌激素及其组合物能够在一定程度上提高荷斯坦奶牛的产奶量、乳蛋白含量和乳糖含量,能够提高奶牛机体抗氧化能力,增强免疫功能。     

亚麻籽木脂素对雄性大鼠肌肉生长的促进作用及机制探讨

 【目的】以大豆黄酮为对照,研究亚麻籽木脂素对雄性大鼠骨骼肌生长的影响并探讨其作用机制。【方法】在SD雄性大鼠基础日粮中分别添加大豆黄酮（5 mg?kg-1）和亚麻籽木脂素（50 mg?kg -1）,利用高压液相色谱、放射免疫分析、RT-PCR等方法,分析大鼠血清中亚麻籽木脂素及两种主要代谢产物（肠内酯、肠二醇）浓度、睾酮及生长激素含量、比目鱼肌和下丘脑中ERβmRNA的相对表达量。【结果】亚麻籽木脂素与大豆黄酮均能显著提高雄性大鼠饲料利用率,促进大腿肌肉增重,提高腿肌中RNA/DNA的比值,促进下丘脑和比目鱼肌中ERβ mRNA表达量显著上升,使大鼠血清中睾酮含量增加,极显著性降低血清中尿素氮含量。【结论】亚麻籽木脂素可能通过与ERβ结合,作用于下丘脑-垂体-性腺轴,调节大鼠血清中睾酮水平,抑制蛋白质分解,促进骨骼肌卫星细胞与肌细胞的融合,从而促进骨骼肌生长。     

瘤胃代谢的神经内分泌调节

反刍动物试验证明,瘤胃液含有17β-雌二醇（E2）、孕酮（P4）和睾酮（T）。E2抑制瘤胃代谢,而P4和T则提高瘤胃代谢水平。这些甾体类激素通过与瘤胃微生物细胞的相应受体结合而直接影响瘤胃内代谢变化。瘤胃液中只发现甲状腺激素的T3,而未检出T4,T3可促进瘤胃微生物代谢活动增强。豆科牧草和大豆含有植物雌激素异黄酮,可提高瘤胃内容物的菌体蛋白、TVFA和氨氮水平。瘤胃液及唾液内发现肽类激素如胃泌素。饲料蛋白在瘤胃内降解可产生一些活性肽,如外啡肽可能起肽类激素的生理作用。半胱胺可耗竭下丘脑和肠道的生长抑素,从而提高生长激素等水平,使瘤胃内代谢及蛋白质合成显著加强。因此,初步认为,瘤胃代谢受神经内分泌的调节,但尚有若干问题有待进一步试验阐明。     

Effects of Oestrogenic Silage on Some Clinical and Endocrinological Parameters in Ovariectomized Heifers

Nwannenna A.I., A. Madej, T.J-O. Lundh and G. Fredriksson: Effects of oestrogenic silage on some clinical and endocrinological parameters in ovariectomized heifers. Acta vet scand. 1994, 35, 173-183.–The influence of phytoestrogens was studied in 3 ovariectomized Swedish Friesian heifers fed 20 kg of 100% red clover silage per heifer/day for 14 days. Behaviour, reproductive organs and pituitary response to exogenous gonadotropin-releasing hormone (GnRH) injections were monitored. Clinical effects like oedema and mucous discharge in the vulva, presence of milky fluid in the mammae and increases in teat size and the cross-sectional distance of the uterus were observed in heifers fed red clover silage. Fluid accumulation in the uterus, visualized by means of ultrasonography, had still not disappeared 30 days after the red clover silage had been completely withdrawn. Red clover silage appeared to reduce the magnitude and duration of the pituitary response to GnRH injections.     

大豆异黄酮的生物活性及在畜牧生产上的应用

大豆异黄酮是一类从大豆种中提取的植物雌激素类物质,主要包括染料木黄酮、大豆黄酮和黄豆黄素.已发现大豆异黄酮具有多种生物活性,如对肿瘤、心血管疾病、骨质疏松症和更年期综合症预防与治疗作用,作为动物饲料添加剂在畜牧生产中也有一定的应用前景.文章主要从大豆异黄酮的生物活性及在畜牧生产上的应用进行了综述.     

异黄酮植物雌激素:反刍动物营养生物学发展与应用前景

本文对异黄酮植物雌激素的种类、测定方法及在动物体内代谢规律进行了综述 ,同时也就该激素对生殖和乳腺发育双向作用进行了评述 ,最后对其研究和应用前景进行了展望     

Dietary isoflavone intake and tissue concentration in cultured sturgeons

A common global trend in modern aquaculture is to reduce or replace fishmeal in fish diets with alternative protein sources, mainly from protein‐rich plants such as soybean; however, plant‐based aquafeeds are a source of substantial amounts of phytoestrogens. Phytoestrogens belong to endocrine‐disrupting chemicals (EDCs) which can negatively interfere with fish reproduction; thus, they should be avoided in sturgeon diet. Therefore, the aim of the study was to evaluate concentrations and the profile of dietary isoflavone phytoestrogens in the two commercial sturgeon diets. A substantial amount of isoflavones, reaching in total from 1.5 to 50 mg/kg of feed, were found in analysed diets. Genistein and daidzein, which are typical constituents of soybean, were the most abundant phytoestrogens in the analysed feeds. Equol, the third most abundant phytoestrogen in the tested samples, was originated most probably from animal components. Additionally, the accumulation of dietary isoflavones in the liver, blood and gonads of two commonly farmed sturgeon species (Acipenser gueldenstaedtii and Acipenser baerii) after long‐term dietary exposure was also assessed. Significant concentrations of isoflavones were found in liver and blood samples of both sturgeon species at 600th and 800th dph, indicating high accumulation of these compounds, which may lead to endocrine disturbance.