表没食子儿茶素没食子酸酯的生理功能及其在畜禽生产中的应用

表没食子儿茶素没食子酸酯(EGCG)是绿茶茶多酚的主要成分,因其具有抗氧化、抗炎、抗病毒、抗肿瘤等多种生理作用,在畜禽生产中具有广阔的应用前景.本文综述了 EGCG抗氧化、抗炎、抗病毒、调节脂质代谢、提高机体免疫力的功能及其在猪、禽类、反刍动物生产中的应用,以期为EGCG在畜禽生产中的应用提供理论依据.     

表没食子儿茶素没食子酸酯对猪精液常温保存效果的影响

为探究不同浓度表没食子儿茶素没食子酸酯(EGCG)对猪精液常温保存效果的影响,该试验通过在猪精液常温保存基础稀释液中添加0、5、10、20、30、40、50μmol/L EGCG,检测保存过程中精子活率、质膜完整率、顶体完整率等指标.结果表明:⑴猪精液常温保存基础稀释液中添加EGCG可以显著提高精子活率、质膜完整率和顶...     

日粮添加不同浓度茶多酚对芦花鸡蛋中表没食子儿茶素没食子酸酯和儿茶素富集、蛋品质及产蛋量的影响

为了探讨日粮中添加不同浓度茶多酚(TP)对芦花鸡蛋中表没食子儿茶素没食子酸酯(EGCG)含量、儿茶素(C)含量、蛋品质及产蛋量的影响,试验随机选用255只26周龄健康芦花鸡,分为6组,每组42只或43只,第1组为对照组,饲喂基础日粮;第2～6组为不同水平TP组,分别在基础日粮中添加0.2%、0.6%、1.0%、1.4%、1.8%TP。于试验第7,14,28天,从每组随机选取鸡蛋检测EGCG和C含量、蛋品质及产蛋量。结果表明：整个试验期间,1.8%TP组蛋黄中EGCG含量显著高于对照组及0.2%、0.6%TP组(P<0.05),且第14天1.8%TP组蛋黄中EGCG含量最高,为33.278μg/g。第7,14天,1.8%TP组蛋清中EGCG含量显著高于对照组和其他各水平TP组(P<0.05);第28天,1.4%和1.8%TP组蛋清中EGCG含量显著高于其他各水平TP组(P<0.05),且1.8%TP组蛋清中EGCG含量最高,为30.790μg/g。第7天,1.8%TP组蛋黄、蛋清中C含量显著高于对照组及0.2%、0.6%和1.0%TP组(P<0.05);第14,2...     

饲粮中添加甜菜碱和表没食子儿茶素没食子酸酯对育肥猪生长性能、肉品质、血清生化和抗氧化指标的影响

本试验旨在研究饲粮中添加甜菜碱和表没食子儿茶素没食子酸酯（EGCG）对育肥猪生长性能、肉品质、血清生化和抗氧化指标的影响。选取81头平均体重为90.03 kg的育肥期“杜×长×大”三元杂交猪,随机分为3组,每组3个重复,每个重复9头猪。对照组饲喂基础饲粮,试验Ⅰ组在基础饲粮中添加2 500 mg/kg的甜菜碱,试验Ⅱ组在基础饲粮中添加2 500 mg/kg的甜菜碱和1 000 mg/kg的EGCG。预试期5 d,正试期40 d。结果表明：1）与对照组相比,试验Ⅰ、Ⅱ组的平均日采食量均显著降低（P<0.05）。2）与对照组相比,试验Ⅰ、Ⅱ组的背膘厚和背最长肌24 h滴水损失均显著降低（P<0.05）,试验Ⅰ组的背最长肌肌内脂肪含量显著升高（P<0.05）。3）各组之间背最长肌氨基酸含量均无显著差异（P>0.05）。与对照组相比,试验Ⅰ、Ⅱ组的背最长肌二十二碳酸含量均显著降低（P<0.05）;各组之间背最长肌其他脂肪酸含量均无显著差异（P>0.05）。4）与对照组相比,试验Ⅰ组的背最长肌肌球蛋白重链Ⅱb(MyHCⅡb)的mRNA相对表达水平显著降低（P&...     

表没食子儿茶素没食子酸酯对金华猪生产性能、肉品质、肠道菌群及抗氧化能力的影响

试验旨在研究饲粮中添加表没食子儿茶素没食子酸酯（EGCG）对金华猪生长性能、肉品质、机体抗氧化能力和肠道微生物组成的影响。选取24头平均体重为59.76 kg的金华猪（阉公猪）,随机分为对照组（基础饲粮）和EGCG组（基础饲粮中添加0.3%EGCG）,每组12头,3个重复,每个重复4头,试验预试期7d,正试期40d。结果表明：与对照组相比,EGCG组降低了金华猪的日均采食量（P<0.05）及耗料增重比（P<0.05）;饲粮中添加0.3%EGCG可提高眼肌面积（P<0.05）,降低平均背膘厚（P<0.05）;饲粮中添加0.3%EGCG降低了血清甘油三酯含量和血清及肝脏的丙二醛含量（P<0.05）,提高了血清超氧化物歧化酶和过氧化氢酶活性（P<0.05）,提高了肝脏谷胱甘肽过氧化物酶活性（P<0.05）;与对照组相比,EGCG组放线菌门（Actinobacteria）相对丰度降低（P <0.05）,粪球菌属3(Coprococcus＿3)、瘤胃梭菌属9(Ruminiclostridium＿9)和多尔氏菌属（Dorea）的相对丰度升高（P<...     

茶多酚对牛乳过敏原αs1-酪蛋白构象和抗原性的影响

为探明茶多酚对αs1-酪蛋白构象和抗原性的影响,选用茶多酚中活性较强的表没食子儿茶素没食子酸酯（epigallocatechin gallate,EGCG）和表没食子儿茶素（epigallocatechin,EGC）接枝αs1-酪蛋白。通过荧光光谱、同步荧光光谱和圆二色谱研究αs1-酪蛋白构象变化,通过间接竞争酶联免疫方法、免疫印迹实验分析αs1-酪蛋白抗原性变化。结果表明：EGC、EGCG均对αs1-酪蛋白内部荧光有猝灭作用,对αs1-酪蛋白的酪氨酸（tyrosine,Tyr）和色氨酸（tryptophan,Trp）残基均有影响,αs1-酪蛋白的α-螺旋和β-折叠含量略有增加,无规卷曲含量略有降低;αs1-酪蛋白构象的变化导致其抗原性显著降低,EGCG对αs1-酪蛋白构象和抗原性的影响显著强于EGC。     

表没食子儿茶素没食子酸酯对福美双诱导的肉鸡胫骨软骨发育不良的影响

旨在研究表没食子儿茶素没食子酸酯(EGCG)通过调控热休克蛋白HSP90的表达对肉鸡胫骨软骨发育不良(TD)的影响。试验将120羽1日龄健康AA肉鸡预饲1周后随机分成3组:对照组、TD发生组和EGCG处理组。通过向基础日粮中添加药物的方式,分别对TD发生组和EGCG处理组雏鸡饲喂25mg/kg的福美双,诱发TD。从第3日起,对EGCG处理组雏鸡每天腹腔注射10mg/kg的EGCG。14d后,全部扑杀试验鸡。形态学检查肉鸡胫骨生长板发育状况;HE染色法观察生长板软骨细胞分化和血管生成变化;Real-time PCR和Western blot法分别检测HSP90基因和蛋白表达差异。结果显示,TD发生组雏鸡TD症状明显,HSP90基因和蛋白表达量均明显上升。EGCG处理组雏鸡TD症状明显缓解,HSP90基因和蛋白表达量显著下降;生长板软骨细胞分化和血管浸润显著恢复。由此推测,EGCG可能通过下调HSP90基因和蛋白在TD肉鸡软骨细胞中的表达,恢复TD胫骨病变区软骨细胞分化和血管生成,抑制TD发生,提高肉鸡健康状况。     

表没食子儿茶素没食子酸酯用于小鼠卵母细胞体外培养的效果观察

本试验以小鼠为动物模型,采用HTF和TCM-199两个基础培养体系,通过添加不同浓度的表没食子儿茶素没食子酸酯(EGCG),研究其对小鼠卵母细胞体外成熟、体外受精及其后期胚胎发育的影响。结果表明,在HTF和TCM-199体系中,培养卵丘-卵母细胞复合物(COCs)时EGCG的最佳添加量均为20μmol/L,可以显著提高卵母细胞的成熟率、受精率和胚胎发育率。过量添加EGCG则有负面的效应。综合比较,HTF体系的培养效果优于TCM-199体系。     

表没食子儿茶素没食子酸酯对育肥猪骨骼肌纤维类型的影响

本试验主要研究在饲粮中添加表没食子儿茶素没食子酸酯(Epigallocatechin gallate,EGCG)对育肥猪肌纤维类型的影响。试验选用156日龄杜×长×大三元杂交育肥猪180头,平均体重为(85.02±1.15)kg,按组间体重、性别比例一致的原则,将育肥猪随机分成3组,每组6个重复,每个重复10头猪(5公5母)。对照组饲喂基础饲粮,试验组饲喂在基础饲粮上分别添加0.025%、0.05%EGCG的试验饲粮。研究结果表明:1)育肥猪饲粮中添加0.025%的EGCG,能显著下调背最长肌乳酸脱氢酶(Lactate dehydrogenase,LDH)的活性(P0.05),减少MyHCⅠ、PGC-1α和mtTFA蛋白水平和MyHCⅠ、Tnnt 1、Cytc和COXⅣmRNA的表达(P0.05);显著下调腰大肌LDH和琥珀酸脱氢酶(Succinate dehydrogenase,SDH)的活性(P0.05),显著上调Ⅰ型肌纤维比例(P0.05),显著下调MyHCⅠmRNA的表达(P0.05),而MyHCⅡa、MyHCⅡx、MyHCⅡb的mRNA显著上调(P0.05)。2)育肥猪饲粮中添加0.050%的EGCG,能显著下调背最长肌LDH和SDH的活性(P0.05),降低活性氧(Reactive oxygen species,ROS)水平(P0.05),抑制AMPK的磷酸化、下调MyHCⅠ、PGC-1α、mtTFA和NRF-1的蛋白和mRNA表达(P0.05);显著下调腰大肌LDH和SDH的活性(P0.05),降低ROS水平(P0.05),下调MyHCⅠ蛋白和mRNA的表达、抑制AMPK的磷酸化和NRF-1的蛋白表达(P0.05),显著上调Ⅰ型肌纤维比例(P0.05)。综上,育肥猪饲粮中添加EGCG后,可能通过EGCG清除ROS后引起AMPK活性减弱,降低PGC-1α表达,最终导致线粒体生物合成下降和慢肌纤维形成减少。     

Effects of epigallocatechin gallate on lipid metabolism and its underlying molecular mechanism in broiler chickens

The objective of this study was to investigate the effects of epigallocatechin gallate (EGCG) on fat metabolism and to establish the molecular mechanism of these effects in broilers. Seventy‐two 28‐day‐old male Ross 308 broiler chickens were divided into three groups with different levels of EGCG supplementation for 4 weeks: normal control (NC) group, L‐EGCG (a low‐level supplement of EGCG, 40 mg/kg body weight daily) and H‐EGCG (a high‐level supplement of EGCG, 80 mg/kg body weight daily). After 4 weeks of oral administration, EGCG significantly reduced the level of abdominal fat deposition in broilers. The serum triglycerides and low‐density lipoprotein cholesterol of chickens in H‐EGCG group were also significantly decreased compared with the NC group, and the high‐density lipoprotein cholesterol was notably increased at the same time. Moreover, the vital role of the liver and abdominal adipose tissue in lipid metabolism of poultry animals was examined through gene expression and enzyme activities related to fat anabolism and catabolism in these organs. Our data show that EGCG supplementation for 2 weeks significantly downregulated the expression of fatty acid synthesis and fat deposition‐related genes, and upregulated the expression of genes involved in fatty acid β‐oxidation and lipolysis genes. Simultaneously, the activities of hepatic fatty acid synthesis enzymes (fatty acid synthase and acetyl CoA carboxylase) were significantly decreased, and the activity of carnitine palmitoyl transferase‐1 was notably elevated. The results suggest that EGCG could alleviate fat deposition in broilers through inhibiting fat anabolism and stimulating lipid catabolism in broilers.     

茶多酚对朗德鹅产肝性能和血清脂类成分的影响

采用单因素试验设计方案。将14周龄、体重相近的健康公朗德鹅150只随机分成5组,每组30只,每只一个重复。对照组饲喂基础日粮,试验组在基础日粮基础上分别添加40、80、160、320mg/kg茶多酚,以研究茶多酚对朗德鹅产肝性能和血清脂类成分的影响。试验结果表明,1)160mg/kg添加组肥肝重、肝屠比,与对照组和320mg/kg添加组均差异显著(P<0.05),肝体比与对照组和320mg/kg添加组差异均显著(P<0.01)。2)320mg/kg添加组血清甘油三酯含量(TG)与对照组和其他试验组差异均显著(P<0.05);320mg/kg添加组血清总胆固醇含量(TC)与对照组差异均显著(P<0.05),与其他试验组差异不显著(P>0.05);高密度脂蛋白胆固醇(HDL-C)和低密度脂蛋白胆固醇(LDL-C)各组差异均不显著(P>0.05)。试验结论:在玉米型日粮添加40￣160mg/kg均能提高朗德鹅产肝性能,添加160mg/kg茶多酚朗德鹅产肝性能最佳,添加320mg/kg茶多酚能显著降低血清TG和TC含量。     

异黄酮对蛋鸡生产性能和脂类代谢的影响

选择400羽40周龄伊莎产蛋鸡来研究大豆黄酮、伊普异黄酮和染料木素3种异黄酮对蛋鸡生产性能以及脂类代谢的影响。试验随机分为4个处理,对照组饲喂基础日粮,3个试验组日粮分别添加6 mg/kg的大豆黄酮、伊普异黄酮和染料木素,试验为6周。结果表明:(1)大豆黄酮组产蛋率显著提高5.1%(P<0.05),料蛋比下降6.3%(P<0.05),其余2组有改善趋势;(2)大豆黄酮显著降低血清总胆固醇、甘油三酯、游离脂肪酸含量,分别较对照组降低27.97%(P<0.01)、43.41%(P<0.05)、44.96%(P<0.01);染料木素显著降低血清总胆固醇和甘油三酯,降幅分别为24.80%(P<0.05)、33.72%(P<0.05);(3)大豆黄酮显著降低血清T3和FT3,显著升高血清T4、FT4和雌二醇水平,伊普异黄酮显著升高血清T4水平;(4)大豆黄酮有降低蛋黄中总胆固醇的趋势。     

共轭亚油酸鸡蛋对小鼠血脂和抗氧化功能的影响

选用体质量、日龄接近的昆明小鼠48只,平均分成4组,每组12只,分别饲喂普通鸡蛋和共轭亚油酸（CLA）含量分别为0.1%,0.5%,1.0%的鸡蛋,3个月后测血脂水平、肝脏脂质过氧化值,并观察主动脉变化情况。结果显示,饲喂含CLA鸡蛋的试验组小鼠的总胆固醇（TC）、动脉硬化指数显著小于对照组（P〈0.05）,肝脏丙二醛（MDA）显著低于对照组（P〈0.05）,对照组小鼠主动脉组织结构出现病变,而其他试验组病变较轻或未发生变化;表明CLA鸡蛋对改善血脂构成、防止肝脏脂质过氧化、预防血管脂质病变具有积极作用。     

Effects of isoprothiolane and phytosterol on adipocyte metabolism and fatty acid composition of serum and tissue lipids in rats.

Isoprothiolane at a dose of 250 mg/kg or phytosterol 50 mg/kg was orally administered to rats once a day for 2 weeks. Basal [U-14C]glucose conversion rate to total lipids in isolated adipocytes of the rats was significantly decreased by treatment with isoprothiolane (54%) or phytosterol (82%). Adipocytes from the rats with isoprothiolane released less glycerol than those from control rats only at an epinephrine concentration of 10 microM. The serum level of total cholesterol was depressed by phytosterol ingestion. The level of non-esterified fatty acids (NEFA) was increased by isoprothiolane. Desaturation in fatty acid composition of phospholipid or cholesterol ester was observed in serum, liver and adipose tissue of the rats treated with either drug. These results suggest that either drug may have common effects by preventing lipid deposition into adipocytes and accelerating fatty acid desaturation in tissue lipids.     

Inhibitory effects of epigallocatechin gallate on the propagation of bovine coronavirus in Madin-Darby bovine kidney cells

Epigallocatechin gallate (EGCg) is the main active component of tea polyphenol and shows several biological activities, such as antimicrobial, antitumor‐promoting, anti‐inflammatory and anti‐oxidative activities. In the present study, the inhibitory effect of EGCg on bovine coronavirus (BCV) propagation in Madin‐Darby bovine kidney (MDBK) cells was investigated. EGCg at concentrations of less than 10 µg/mL did not show any cytotoxicity to MDBK cells. BCV propagation was significantly inhibited by pretreatment of the virus with EGCg (0.5–10 µg/mL) before virus inoculation in dose‐dependent, incubation time‐dependent and temperature‐dependent manners. The antiviral effect of pretreating MDBK cells with EGCg on BCV propagation was much weaker than that of pretreating BCV with EGCg. The hemagglutination activity of BCV was also reduced by EGCg in a dose‐dependent manner. These results demonstrate that EGCg possesses a distinct anti‐BCV activity and strongly suggest that EGCg interferes with the adsorption of BCV to MDBK cells by the interaction of EGCg with BCV particles. EGCg may therefore be a useful candidate for controlling BCV infection more effectively.     

Lipid metabolism and hyperlipidemia in dogs

Lipid metabolism in dogs can be divided into exogenous and endogenous pathways and exhibits some unique characteristics compared to other species. Hyperlipidemia is common in dogs, and can be either primary or secondary to other diseases. Secondary hyperlipidemia is the most common form and can be a result of endocrine disorders, pancreatitis, cholestasis, protein-losing nephropathy, obesity, and high fat diets. Primary hyperlipidemia is less common and usually associated with certain breeds. Hypertriglyceridemia of Miniature Schnauzers is the most common type of primary hyperlipidemia in dogs in the United States, and appears to have a genetic basis although its etiology remains unknown. Possible complications of canine hyperlipidemia include pancreatitis, liver disease, atherosclerosis, ocular disease, and seizures. Management is achieved by administration of low fat diets with or without the administration of lipid-lowering agents such as omega-3 fatty acids, gemfibrozil, and niacin.     

Effects of hypercaloric diet-induced hyperinsulinemia and hyperlipidemia on the ovarian follicular development in mice

Long-term hypercaloric diets may adversely affect the development of ovarian follicles. We investigated the effects of high sugar (HS), high fat low sugar (HFLS), and high fat normal sugar (HFNS) diets on the ovarian follicle development in mice fed with these diets as compared to those fed with normal diet (control) for 180 days. Body weight, gonadal fat, glucose, lipid, insulin, estrous cycle, sex hormones and ovarian tissues were examined, and metabolism-related protein expression in the ovaries was evaluated by immunoblotting. The mice fed with hypercaloric diets showed hyperinsulinemia and hyperlipidemia, and exhibited heavier body and gonadal fat weights, longer estrous cycles, and fewer preantral and antral follicles than mice fed with normal diet. The sex hormone levels in the blood were similar to those in controls, except for significantly elevated estradiol levels in the HS diet group. The AMPKα phosphorylation was reduced, while AKT phosphorylation and caspase-3 levels were increased in the ovarian tissues of mice in all three hypercaloric diet groups than those in control. Taken together, the results suggest hyperinsulinemia and hyperlipidemia as possible mechanisms that impair the development of ovarian follicles in response to long-term exposure to unhealthy hypercaloric diets.     

甘露寡糖对断奶仔猪生产性能和血液生化指标的影响

6窝34头体质量相近的杜长大哺乳仔猪随机分为2组,分别于断奶后饲喂基础日粮(对熙组)或基础日粮+甘露寡糖(MOS组)4周,每天记录采食量和剩料量,每周称重,第7和28天采血测定与脂质代谢相关指标,以研究MOS对断奶仔猪日增重、料重比、腹泻率和脂质代谢的影响.结果表明,第1周,MOS对仔猪增重、料重比和腹泻率无显著影响,2周后特别是第2周,可显著促进仔猪增重、降低料重比和减少腹泻发生(P<0.05).血液指标显示,第1周时,两组各血液指标差异不明显(P>0.05),第4周时,MOS组血糖、血甘油三酯(TG)、血总胆固醇(T-CH)、血低密度脂蛋白(LDL)和血极低密度脂蛋白(VLDL)低于对照组,其中TG、LDL和VLDL下降幅度大于对照组,唯有血高密度脂蛋白(HDL)高于对照组,但差异均不显著(P>0.05).以上结果说明,仔猪对MOS有一个适应过程,饲喂2周后可促进仔猪生长,减少腹泻的发生.连续饲用MOS可小幅降低TG、LDL和VLDL,升高HDL,对脂质代谢有一定的影响.     

Effects of endotoxin on carbohydrate metabolism in inbred mice.

Effects of endotoxin on carbohydrate metabolism were studied in A/HeJ (endotoxin-sensitive) and C3H/HeJ (endotoxin-resistant) inbred mice. A/HeJ mice developed hypoglycemia within two hours after endotoxin injection, yet liver glycogen content did not differ from controls. Similarly treated C3H/HeJ mice did not develop significant hypoglycemia. Administration of glucagon to endotoxin-treated A/HeJ mice failed to elevate their blood glucose concentrations, while endotoxin-treated mice of the same strain did respond to dibutyryl cyclic AMP with a significant elevation of blood glucose. C3H/HeJ mice on the other hand responded to glucagon and dibutyryl cyclic AMP with elevated blood glucose. Endotoxin-treated C3H/HeJ but not A/HeJ mice were able to carry out gluconeogenesis induced by prednisolone, while both inbred strains showed active glycogenesis after administration of an exogenous glucose load. Administration of glucagon resulted in diminished liver glycogen concentrations in A/HeJ endotoxin-treated mice suggesting no impairment of glycogenolysis. The inability of endotoxin-treated A/HeJ mice to respond to glucagon could be due to impairment of gluconeogenesis. Although endotoxin interfered with the capacity of both inbred strains to respond to glucagon administration with elevation of liver cyclic AMP, the effect was significantly more severe in A/HeJ mice. The susceptibility of A/HeJ mice to the lethal effect of endotoxin may be related to the apparent sensitivity of carbohydrate metabolic pathways to disturbance by endotoxin.