不同类型膳食脂肪酸对肥胖小鼠肝脏及其血液中脂肪酸组成和代谢相关基因影响

目的探讨不同类型膳食脂肪酸对肥胖小鼠肝脏及其血液中脂肪酸组成及代谢相关基因的影响。方法 8周龄雄性C57BL/6小鼠随机分为7组,即对照组(喂基础饲料)、长链饱和脂肪酸(LCSFA)组(喂猪油高脂饲料)、中链饱和脂肪酸(MCSFA)组(喂椰子油高脂饲料)、n-3多不饱和脂肪酸(n-3 PUFA)组(喂亚麻籽油高脂饲料)、n-6多不饱和脂肪酸(n-6 PUFA)组(喂大豆油高脂饲料)、单不饱和脂肪酸(MUFA)组(喂橄榄油高脂饲料)和反式脂肪酸(TFA)组(喂8%氢化大豆油高脂饲料),每组10只,共干预16周,所有种类饲料总能量均相同,基础饲料脂肪供能比为10%,各高脂饲料脂肪供能比均为45%,喂养周期结束后,禁食12 h,麻醉后立刻解剖取出肝脏。采用气相色谱法分析肝脏及其血液中脂肪酸组成的变化,实时荧光定量聚合酶链式反应(PCR)检测肝脏脂肪酸代谢相关基因的表达,肝脏脂质沉积采用油红O染色法检测。结果与对照组比较,LCSFA组、MCSFA组、n-6 PUFA组、MUFA组和TFA组小鼠肝脏中均出现明显的脂质沉积,n-3 PUFA组小鼠肝脏未出现明显的脂质沉积。与对照组比较,LCSFA组小鼠肝脏及血液中总n-6 PUFA和总PUFA含量升高; n-3 PUFA组小鼠肝脏及血液中总n-3 PUFA和总PUFA含量增加,但总MUFA含量减少; n-6 PUFA组小鼠肝脏及血液中总n-6PUFA、总n-3 PUFA和总PUFA含量升高,但总饱和脂肪酸(SFA)和总MUFA含量降低; MUFA组小鼠肝脏及血液中总SFA含量减少; TFA组小鼠肝脏及血液中C18∶1 n-9t(TFA)含量升高;以上差异均有统计学意义(P0. 05)。LCSFA组和MCSFA组小鼠肝脏脂肪酸代谢基因固醇调节元件结合蛋白1(SREBP-1c) mRNA水平高于对照组和n-6 PUFA组,差异均有统计学意义(P0. 05)。结论小鼠肝脏及其血液中脂肪酸构成与其对应的膳食脂肪酸模式一致。不同类型脂肪酸高脂饲料可通过对相关基因的表达影响肥胖状态下肝脏的脂质代谢及脂质沉积。     

绿茶、白茶水提物对肥胖小鼠血糖、血脂的干预作用及肠道微生物的影响

实验比较不同剂量白茶水提物和绿茶水提物对肥胖小鼠降糖、降脂的效果及对小鼠肠道菌群的影响.随机将48只小鼠分为正常组(CK)6只小鼠、造模组(HFD)6只和造模干预组36只小鼠.造模组分别采用2.5％、5％、10％白茶水提物和绿茶水提物处理.实验结束测定小鼠血糖、血脂,并通过高通量测序技术研究小鼠肠道微生物菌属相对丰度变...     

反式棕榈油酸对肥胖小鼠代谢稳态的作用研究

为了探讨反式棕榈油酸对肥胖小鼠代谢稳态的影响,利用高脂诱导的肥胖模型,观察反式棕榈油酸对小鼠的体重、进食量、空腹血糖、餐后血糖、葡萄糖敏感性、呼吸交换速率(RER)、产热和活动量作用。并采用QPCR和Western BLOT方法分别检测小鼠脂肪代谢相关基因和肝脏炎症相关蛋白质的表达。结果显示,反式棕榈油酸在不影响肥胖小鼠体重、空腹血糖、餐后血糖和肝脏炎症的情况下,可以显著改善葡萄糖敏感性(p 0.01)、抑制食欲(p 0.000 1)、降低皮下脂肪的积累(p 0.05)、增强呼吸代谢(p 0.000 1)和产热(p 0.000 1),但同时动物活动量也显著减少(p 0.001),从而达到一种能量平衡的状态。由此可知,反式棕榈油酸虽然是一种反式脂肪酸,但对肥胖小鼠代谢并无显著有害影响,可为今后筛选安全的膳食食品添加剂研究提供一定的参考。     

DHA-磷脂对肥胖小鼠脂质代谢的影响

研究了二十二碳六烯酸-磷脂（DHA-磷脂）对实验性肥胖小鼠脂质代谢的调节作用及其机制。采用Folch法和硅胶柱层析法从鸢乌贼（文字Sthenoteuthis oualaniensis）卵中分离制备得到富含DHA的磷脂。C57BL/6J雄性小鼠随机分为3组：高脂模型组,1%大豆磷脂组,1%DHA-磷脂组。连续饲喂7周后,测定小鼠血清总胆固醇（TC）、甘油三酯（TG）、高密度脂蛋白胆固醇（HDL-C）含量,肝脏TC、TG、磷脂（PL）含量以及肝脏脂肪合成酶（FAS）、葡萄糖-6-磷酸脱氢酶（G6PDH）、苹果酸酶（ME）、磷脂酸磷酸酶（PAP）、肉毒碱棕榈酸转移酶（CPT）、过氧化物酶体β-氧化活力。结果显示,DHA-磷脂能极显著抑制小鼠体重（P＜0.01）和肾周脂肪（P＜0.01）及精周脂肪（P＜0.01）蓄积,降低血清TC（P＜0.01）和肝脏TG（P＜0.01）水平,抑制肝脏FAS（P＜0.01）、ME（P＜0.05）、PAP（P＜0.05）的活力,提高CPT（P＜0.01）和过氧化物酶体β-氧化（P＜0.05）的活力,且效果优于大豆磷脂。DHA-磷脂具有良好的减肥作用,能够通过抑制肝脏脂质合成,促进脂质分解,有效调节肥胖小鼠的脂质代谢。     

Bovine milk oligosaccharides decrease gut permeability and improve inflammation and microbial dysbiosis in diet-induced obese mice

Obesity is characterized by altered gut homeostasis, including dysbiosis and increased gut permeability closely linked to the development of metabolic disorders. Milk oligosaccharides are complex sugars that selectively enhance the growth of specific beneficial bacteria in the gastrointestinal tract and could be used as prebiotics. The aim of the study was to demonstrate the effects of bovine milk oligosaccharides (BMO) and Bifidobacterium longum ssp. infantis (B. infantis) on restoring diet-induced obesity intestinal microbiota and barrier function defects in mice. Male C57/BL6 mice were fed a Western diet (WD, 40% fat/kcal) or normal chow (C, 14% fat/kcal) for 7 wk. During the final 2 wk of the study, the diet of a subgroup of WD-fed mice was supplemented with BMO (7% wt/wt). Weekly gavage of B. infantis was performed in all mice starting at wk 3, yet B. infantis could not be detected in any luminal contents when mice were killed. Supplementation of the WD with BMO normalized the cecal and colonic microbiota with increased abundance of Lactobacillus compared with both WD and C mice and restoration of Allobaculum and Ruminococcus levels to that of C mice. The BMO supplementation reduced WD-induced increase in paracellular and transcellular flux in the large intestine as well as mRNA levels of the inflammatory marker tumor necrosis factor α. In conclusion, BMO are promising prebiotics to modulate gut microbiota and intestinal barrier function for enhanced health.     

茯砖茶对雌性小鼠急性酒精性肝损伤血清酶的影响

目的:通过实验,研究茯砖茶对雌性小鼠急性酒精性肝损伤血清酶的保护作用。方法:采用单位实验的方法对小鼠饮酒后血清丙二醛和谷胱甘肽过氧化物酶进行研究。结果:砖茶组丙二醛含量低于白酒模型对照组,高于空白对照组;谷胱甘肽过氧化物酶含量高于白酒模型对照组,低于空白对照组。结论:砖茶有效地降低酒精对雌性小鼠的血清酶的损伤。     

泾阳茯茶中冠突散囊菌的鉴定及降脂作用研究

目的 探究陕西泾阳茯砖茶中冠突散囊菌的鉴定标志, 鉴定泾阳茯茶中的冠突散囊菌, 并研究其降脂作用。方法 从泾阳茯茶中分离筛选真菌, 观察其在3种不同培养基的生长特征, 结合形态学观察和真菌内源转录间隔区(internally transcribed spacer, ITS)基因序列同源性比对; 人工接种菌种至不同产区茶类中, 对接种至茶叶中菌种的形态学、扫描电镜(scan electron microscope, SEM)鉴定和接种后茶叶进行感官审评; 最后建立小鼠肥胖模型, 探讨回接冠突散囊菌后黑茶水浸提物对肥胖模型鼠的作用。结果 筛选分离得到的菌株(JY1)为冠突散囊菌(Eurotium cristatum, E.C.); 该菌在几种试验茶类均可以良好“发花”; 除红茶外, 其余茶样闭囊壳较饱满且子囊孢子的“赤道”周围存在较多小孔, 而红茶表现出以分生孢子为主; 接种后的散茶, 在香气, 汤色和滋味上均有不同程度变化; 与肥胖模型组相比较, 发花茶能显著抑制鼠体质量增长和Lee`s指数, 使血清总胆固醇(total cholesterol, TC)下降, 皮下脂肪细胞直径明显变小。结论 陕西泾阳茯茶中冠突散囊菌“赤道”周围存在较多小孔的电镜结果有可能作为陕西茯茶的特异性鉴定标志, 该菌可在黑茶, 红茶, 白茶, 绿茶上优势生长, 不同程度改变接种后的茶叶香气、汤色、滋味。回接冠突散囊菌后黑茶可降低血清总胆固醇水平, 同时有抑制脂肪细胞体积增大的作用, 且作用有一定时效性。     

Anti‐obesity effect of Liupao tea extract by modulating lipid metabolism and oxidative stress in high‐fat‐diet‐induced obese mice

Liupao tea (LPT) is traditional dark Chinese tea. The effect of LPT extract on high‐fat‐diet‐induced obese mice was investigated systematically. The results showed that LPT extract could reduce body weight and significantly alleviate liver damage and fat accumulation. LPT could also decrease the levels of alanine aminotransferase (ALT), aspartate transaminase (AST), alkaline phosphatase (AKP), total cholesterol (TC), triglycerides (TG), and low‐density lipoprotein cholesterol (LDL‐C) and increase the level of high‐density lipoprotein cholesterol (HDL‐C) in the liver. It also decreased the serum levels of inflammatory cytokines, including tumor necrosis factor alpha (TNF‐α), interferon gamma (IFN‐γ), interleukin (IL)‐1β, and IL‐6 and increased the serum levels of anti‐inflammatory cytokines, including IL‐10 and IL‐4. Moreover, LPT improved the levels of total superoxide dismutase (T‐SOD), glutathione peroxidase (GSH‐Px), and catalase (CAT) and reduced the level of malondialdehyde (MDA) in the liver. Moreover, LPT could upregulate the mRNA and protein expressions of peroxisome proliferator‐activated receptor alpha (PPAR‐α), lipoprotein lipase (LPL), carnitine palmitoyltransferase 1(CPT1), and cholesterol 7 alpha‐hydroxylase (CYP7A1) and downregulate those of PPAR‐γ and CCAAT/enhancer‐binding protein alpha (C/EBP‐α) in the liver. It also increased the mRNA expression of copper/zinc superoxide dismutase (SOD1), manganese superoxide dismutase (SOD2), CAT, gamma‐glutamylcysteine synthetase 1 (GSH1), and GSH‐Px. The components of LPT extract include catechin, rutin, taxifolin, and astragalin, which possibly have a wide range of biological activities. In conclusion, our work verified that LPT extract possessed an anti‐obesity effect and alleviated obesity‐related symptoms, including lipid metabolism disorder, chronic low‐grade inflammation, and liver damage, by modulating lipid metabolism and oxidative stress.     

茯砖茶水提物对高脂血症小鼠脂质代谢的影响 及其抗氧化作用的研究

目的考察茯砖茶的降血脂及肝保护作用。方法用高脂饲料饲喂小鼠建立高脂血症动物模型,以不同剂量(50 mg/kg·BW、150 mg/kg·BW、300 mg/kg·BW)茯砖茶水提物给小鼠每天灌胃,连续4周后检测血清中总胆固醇(TC)、甘油三酯(TG)、低密度脂蛋白胆固醇(LDL-C)、高密度脂蛋白胆固醇(HDL-C)水平。同时观察其对肝组织谷胱甘肽过氧化物酶(GSH-Px)、超氧化物歧化酶(SOD)、丙二醛(MDA)、体重、肝体比及肝组织病理变化的影响。结果结果显示,与模型组相比,茯砖茶水提物可呈剂量依赖性地降低血清中TC、TG、LDL-C的水平,提高HDL-C的含量。茯砖茶水提物还可以显著降低小鼠体重、肝体比及肝组织中MDA含量,极显著提高肝组织中GSH-Px和SOD活性,并减轻了肝脏的脂肪变性程度。结论茯砖茶水提物有较明显地改善脂质代谢和抗氧化的作用。     

C57BL/6J伪无菌与SPF小鼠高脂饮食诱导的比较研究

肠道菌群与宿主肥胖密切相关,伪无菌小鼠动物模型是研究肠道菌群与肥胖及其他相关疾病关系的有利"工具"。20只8周龄C57BL/6J雄性小鼠给予抗生素混合物饮水,剔除大部分肠道微生物模拟无菌动物。随机分成两组:对照组和高脂组,分别饲喂常规纯化饲料与高脂纯化饲料8周;同时以20只SPF级小鼠作对照。常规方法测定小鼠体重、血清中血糖、血脂指标和胰岛素水平,并用软件测量脂肪细胞大小。结果表明,与高脂组SPF小鼠相比,高脂组伪无菌小鼠的体重、脂肪垫与肾周脂重量显著低于高脂组SPF小鼠;胰岛素水平和脂肪细胞大小也显著低于SPF小鼠。高脂组伪无菌小鼠出现低体重低脂肪的表型,与无菌小鼠动物模型极为相似。因此采用抗生素处理建立伪无菌小鼠动物模型可用来预示无菌小鼠试验的结果,是研究肠道菌群与某些疾病的理想动物模型。     

The influence of selenium on the antioxidant activity of green tea

This study was aimed at determining the effects of selenium on the contents of vitamin C, amino acid, total water‐soluble solids and tea polyphenol, and whether the antioxidant activity of selenium‐enriched green tea is enhanced compared with regular green tea by linoleic acid oxidation and the lard oxidation method. The contents of selenium, vitamin C and tea polyphenol in green teas were greatly increased by foliar application of selenium‐enriched fertilizer. No significant differences of the contents of vitamin C, amino acid and tea polyphenol were observed between green tea treated with sodium selenite and that without selenium. The selenium‐enriched green tea exhibited significantly higher antioxidant activity than regular green tea, both in linoleic acid oxidation and in the lard oxidation system. These results suggest that the antioxidant activity of green tea is significantly enhanced by the combination of selenium and green tea constituents compared with that of regular green tea. Copyright © 2003 Society of Chemical Industry     

原花青素对营养肥胖模型大鼠肠道消化酶活性的影响

以高脂饲料喂养Wistar大鼠建立营养肥胖模型,然后以200 mg/（kg·bw·d）葡萄籽原花青素提取物灌胃6周,研究其对大鼠体重,以及蛋白酶、淀粉酶、脂肪酶、α-葡萄糖苷酶、β-葡萄糖苷酶等肠道内酶活性的影响。造模结束时,模型组、灌胃组体重及Lee’s指数无显著区别,且显著高于正常组（p<0.05）;灌胃6周葡萄籽原花青素后,灌胃组体重及Lee’s指数显著低于模型组（p<0.05）。灌胃组大鼠肠道蛋白酶、脂肪酶活性显著（p<0.05）高于模型组和正常组;灌胃组淀粉酶活性显著（p<0.05）高于正常组,与模型组无显著区别（p>0.05）;灌胃组α-葡萄糖苷酶活性与模型组和正常组无显著区别;灌胃组β-葡萄糖苷酶活性显著（p<0.05）低于模型组和正常组。实验结果显示200 mg/（kg·bw·d）浓度的提取物可显著抑制大鼠肥胖,且提高了肠道消化酶的活性,有利于营养物质的吸收利用,同时降低了二糖酶中β-葡萄糖苷酶的活性,有利于降低血糖。      

茶叶减肥降脂机制研究进展

肥胖是由于食欲调节和能量代谢功能长期紊乱引起的体内脂肪积累。肥胖与多种疾病密切相关,因此寻求高效、安全的减肥药物成为人们的共同愿望。茶叶因其良好的降脂减肥效果,日益引起国内外众多学者的关注。近年来,茶叶减肥机理成为研究的热点,并取得了显著成效。本文综述了最近几年对茶叶减肥作用的机理研究,即茶叶及其组分抑制营养吸收、改善脂质代谢、促进脂肪细胞凋亡和调节肥胖相关基因等方面的研究进展。      

Green tea polyphenols reduce obesity in high‐fat diet‐induced mice by modulating intestinal microbiota composition

In this study, the modulatory effect of green tea polyphenols (GTP) on human intestinal microbiota was investigated. Firstly, germ‐free mice were inoculated with faecal suspension derived from healthy volunteers to obtain human flora‐associated (HFA) mice model. When the high‐fat diet‐induced obese mice model was successfully established, they were randomly divided into high‐fat diet group (HFD) and high‐fat diet group with GTP (HFD‐GTP), and the shifts in relative abundance of the dominant taxa at the phylum, family and genus levels were studied by high‐throughput sequencing. The diversity of the total bacterial community reached the maximum after GTP treatment for 3 weeks, and then decreased when the mice were fed without GTP. Despite interindividual variation, the relative abundance of Bacteroidetes increased from 0.56 ± 0.06 (1st week) to 0.60 ± 0.05 (3th week), while Firmicutes decreased from 0.42 ± 0.06 to 0.37 ± 0.02. Interestingly, certain bacterial communities such as Bacteroidetes and Proteobacteria still increased and Firmicutes showed a decreasing trend when the mice were fed without GTP (4th week). The results showed that GTP benefits the stability of certain gut microbiota, especially in an environment‐triggered microbial imbalance; therefore, it may have prebiotic‐like activity contributing to the prevention of obesity.