素馨花水提物及其主要成分对3T3-L1细胞成脂分化的影响

该研究探讨素馨花水提物（WE）及其化学成分在3T3-L1前脂肪细胞上的降脂作用。通过将3T3-L1细胞诱导为成熟脂肪细胞,油红Ｏ染色定量和检测甘油三酯（TG）含量判断素馨花样品对脂滴的抑制作用;液质联用仪分析WE中化学成分;MTT检测素馨花及其成分对3T3-L1细胞增殖的影响;Western Blot检测AMPK、C/EBPα、FAS、ACC、CPT1、Bax、Bcl-2等蛋白表达。结果发现,WE能剂量依赖性抑制脂滴形成,其中高浓度WE（500 µg/mL）能降低中性脂质含量23.59%,降低TG含量30.20%,在脂肪积累早期作用最显著,并证明其活性成分主要是橄榄苦苷,含量为13.77%。WE及橄榄苦苷能激活AMPK（123.19%和115.98%）和其下游靶点ACC（451.06%和1 050.0%）的磷酸化、下调其下游靶点FAS（81.72%和60.50%）的蛋白表达,减少脂肪形成,提高CPT1（164.84%和292.19%）蛋白的表达,加快脂肪酸氧化;抑制C/EBPα（68.97%和34.57%）的表达,影响3T3-L1细胞分化;上调Bax（154.60%和139.37%）、下调Bcl-2（41.10%和45.62%）蛋白的表达,诱导脂肪细胞凋亡。结果提示,WE能在3T3-L1细胞分化过程早期抑制细胞生长、分化和脂肪合成并促进脂肪酸氧化从而有效抑制脂质积累,机制上可能通过调控AMPK和Bax/Bcl-2通路。     

异甘草素对3T3-L1前脂肪细胞分化的抑制作用

目的：考察异甘草素对3T3-L1前脂肪细胞分化的影响,探究其作用机制。方法：采用3T3-L1前脂肪细胞,利用磺酰罗丹明B（sulforhodamine B,SRB）法检测异甘草素对3T3-L1前脂肪细胞增殖的影响,采用传统的鸡尾酒法诱导3T3-L1细胞分化为脂肪细胞,利用油红O染色法检测分化细胞脂滴形成;采用实时荧光定量逆转录聚合酶链式反应方法,检测细胞CCAAT增强子结合蛋白（CCAAT-enhancer-binding proteins,C/EBP）亚型C/EBPα、C/EBPβ、脂肪酸合成酶（fatty acid synthetase,FAS）、脂肪分化相关蛋白adipophilin、过氧化物酶体增殖物激活受体γ（peroxisome proliferators activated receptor γ,PPARγ）、腺苷酸活化蛋白激酶（adenosine monophosphateactivated protein kinase,AMPK）的mRNA表达水平,Western blotting法检测AMPK蛋白磷酸化水平。结果：异甘草素可浓度依赖性地抑制3T3-L1细胞增殖,并明显抑制分化细胞内脂滴形成,同时抑制了细胞分化相关基因C/EBPα、C/EBPβ、FAS、adipophilin、PPARγ mRNA的表达,AMPK mRNA的表达未受影响,但异甘草素处理明显上调了AMPK蛋白的磷酸化水平。结论：异甘草素可抑制3T3-L1前脂肪细胞向脂肪细胞分化,其机制可能与活化AMPK信号通路相关。     

蕨菜提取物抗肥胖作用及其机制

研究蕨菜对3T3-L1前脂肪细胞分化和高脂饮食诱导C57BL/6J小鼠肥胖的抑制作用,初步探讨其作用机制。培养3T3-L1前脂肪细胞并诱导其分化,油红O染色比色分析蕨菜乙醇提取物(PAE)对其分化程度的影响,Western blot法检测其对脂肪细胞分化转录调控因子(PPARγ、CEBPα、SREBP-1c)与脂质合成相关基因(FAS、ACC)的表达水平。以高脂饮食6周建立C57BL/6J肥胖小鼠模型,将诱导成功的肥胖小鼠分为高脂对照组(HFD)、1%蕨菜乙醇提取物组(HFD+PAE),另设立正常饲料喂养的C57BL/6J小鼠为正常组(ND)。继续喂养8周后测定各组小鼠体质量,评价其脂代谢状况(甘油三酯、胆固醇)及糖代谢情况(血糖、葡萄糖耐量)。结果显示,PAE能显著抑制3T3-L1前脂肪细胞分化,减少细胞中脂质的沉积。PAE显著影响脂肪细胞分化过程中细胞分化转录调控因子PPARγ、CEBPα、SREBP-1c的蛋白表达(P0.05),同时降低脂质合成相关基因FAS、ACC的表达(P0.05)。经过高脂饮食诱导C57BL/6J肥胖小鼠体质量增加,体脂沉积显著,血糖、血脂水平明显高于ND组(P0.05)。PAE干预后,小鼠体质量、甘油三酯、血糖水平均较HFD明显降低(P0.05),葡萄糖耐量也得到显著改善(P0.05)。蕨菜乙醇提取物抑制了3T3-L1脂肪细胞分化,改善了肥胖小鼠体质量,消除了高血脂和高血糖异常,修复了葡萄糖耐量,这一作用可能与其调控脂肪细胞分化转录调控因子和脂质合成相关基因等密切相关。     

洋葱皮黄酮抑制脂肪细胞生成作用

以乙醇提取洋葱皮中黄酮类化合物,通过正交试验优化提取工艺,验证实验显示洋葱皮黄酮提取率为21.58%。通过制备液相分离黄酮类化合物单体,作用于3T3-L1前脂肪细胞,测定了洋葱皮黄酮类单体诱导分化第8天的3T3-L1前脂肪细胞中脂肪分化相关基因FAS的mRNA表达量。结果表明:槲皮素对3T3-L1前脂肪细胞分化抑制效果最好,加药处理组FAS的mRNA相对表达量都低于对照组的基因表达量,且槲皮素处理组基因表达量下调极为显著(P0.01),说明洋葱皮中通过制备分离的黄酮类单体化合物对3T3-L1前脂肪细胞分化具有抑制效果,抑制效果大小为槲皮素山奈酚芦丁。     

辣木异硫氰酸酯通过活化AMPK抑制3T3-L1脂肪细胞脂质积累

探究辣木异硫氰酸酯-4-[(α-L-rhamnosyloxy) benzyl] Isothiocyanates（MIC-1）抑制3T3-L1脂肪细胞脂质积累的作用及可能的调控机制。体外诱导3T3-L1前脂肪细胞分化为成熟脂肪细胞,用MIC-1干预48 h后检测细胞脂质积累情况,甘油三酯（TG）、甘油（Gly）和游离脂肪酸（FFA）含量;qRT-PCR检测脂代谢相关基因的表达;Western blot法测定腺苷酸活化蛋白激酶（AMPK）蛋白磷酸化水平和氧化物酶体增殖激活受体γ（PPARγ）蛋白表达水平。结果表明,MIC-1对3T3-L1前脂肪细胞存活率无影响;与对照组相比,MIC-1可降低脂肪细胞内脂滴分布及细胞着色程度,降低细胞内TG含量,减少FFA及甘油的溢出。MIC-1处理浓度达4 mol/L时,TG和FFA浓度分别下降64.00%和75.00%。同时,显著下调细胞中PPARγ（46.00%）、硬脂酰辅酶A去饱和酶1（SCD1）（62.00%）的mRNA表达水平;显著上调AMPK蛋白磷酸化水平（64.47%）和下调PPARγ（52.10%）蛋白表达水平。以上结果表明,MIC-1通过促进TG分解和抑制TG的合成,从而抑制脂质积累,其机制可能与AMPK的活化有关。     

不同茶多糖对3T3-L1前脂肪细胞分化的抑制作用比较

本实验利用小鼠3T3-L1前脂肪细胞对绿茶多糖（green tea polysaccharides,GTP）、红茶多糖（black tea polysaccharides,BTP）和乌龙茶多糖（oolong tea polysaccharides,OTP）的减肥作用进行评价。使用气相色谱对GTP、BTP、OTP的单糖组成进行分析。采用噻唑蓝染色法测定3?种茶多糖（tea polysaccharides,TPs）对3T3-L1前脂肪细胞增殖活力的影响。使用流式细胞仪检测3?种TPs对3T3-L1前脂肪细胞细胞周期的影响。采用传统“鸡尾酒”法诱导3T3-L1细胞分化成脂后,测吸光度并计算其分化率。采用甘油磷酸氧化酶-过氧化物酶（glycerol phosphate oxidase-peroxidase,GPO-PAP）法测定细胞中甘油三酯（triglyceride,TG）含量的变化。采用实时荧光定量聚合酶链式反应（real-time polymerase chain reaction,RT-PCR）技术测定与脂质代谢相关基因的表达量。结果显示3?种TPs均能显著抑制3T3-L1前脂肪细胞的增殖与分化（P＜0.05）。添加100?μg/mL的TPs能使细胞分化率显著下降至（62.00±6.61）%（GTP）、（82.95±4.25）%（BTP）、（97.24±5.80）%（OTP）。另外,在细胞培养至第5天检测表明,这3 种TPs显著促进G0/G1期细胞数量的累积,细胞比例分别为（68.52±2.28）%（GTP）、（67.11±1.68）%（BTP）、（59.69±1.35）%（OTP）。RT-PCR分析结果显示TPs可以调控相关脂肪细胞因子的表达。在本研究中,在3T3-L1前脂肪细胞中GTP的减肥作用强于BTP和OTP。TPs的加入上调脂联素的表达从而激活腺苷酸活化蛋白激酶信号通路调控相关脂肪细胞因子的表达,并最终抑制TG的合成与3T3-L1前脂肪细胞的分化。     

新橙皮苷对3T3-L1前脂肪细胞分化的影响及其作用机制

为探讨新橙皮苷对脂肪细胞脂肪形成的影响及其作用机制,采用MTS法检测新橙皮苷对3T3-L1前脂肪细胞的细胞活力的影响,确定新橙皮苷的作用浓度后,油红O染色法和分光光度法测定3T3-L1脂肪细胞的分化及胞内甘油三酯的含量,RT-PCR测定脂肪形成相关基因CCAAT增强子结合蛋白α（CCAAT/enhancer binding proteinα,C/EBPα）和过氧化物酶体增殖激活受体γ（Peroxisome proliferators-activated receptorγ,PPARγ）mRNA表达,Western蛋白印迹法检测蛋白激酶B（Protein kinase B,PKB/Akt）、糖原合成酶激酶3β（Glycogen synthase kinase3β,GSK3β）和糖原合成酶（Glycogen synthase,GS）的磷酸化水平;利用GSK3β选择性的抑制剂LiCl作用3T3-L1脂肪细胞后,检测新橙皮苷对3T3-L1细胞分化、胞内甘油三酯含量、C/EBPα、PPARγ及aP2蛋白表达的影响。结果表明,新橙皮苷能极显著抑制脂肪细胞分化和胞内甘油三酯的形成（P<0.01）,激活Akt信号通路,促进p-Akt和p-GSK3β水平增加,极显著抑制C/EBPα、PPARγ、aP2 mRNA和蛋白表达（P<0.01）。新橙皮苷的这些影响部分地被GSK3β抑制剂LiCl所抑制（P<0.01）。新橙皮苷能够通过激活Akt/GSK3β信号通路抑制脂肪细胞分化。     

6-磷酸葡萄糖酸脱氢酶在产油细菌浑浊红球菌PD630脂质积累中的作用

产油微生物脂质合成的过程已基本清晰:乙酰辅酶A和还原力NADPH在脂肪酸合酶(FAS)的作用下合成脂肪酸。产油微生物菌体内主要有苹果酸酶(ME)、葡萄糖-6-磷酸脱氢酶(G6PDH)、6-磷酸葡萄糖酸脱氢酶(6PGDH)和异柠檬酸脱氢酶(ICDH)为其脂质合成提供所需还原力NADPH。为了研究6PGDH在浑浊红球菌PD630(Rhodococcus opacus PD630)脂质积累中的作用,作者将编码氧化磷酸戊糖路径(oxPPP)中6PGDH的基因gnd在R. opacus PD630中过表达。结果表明,与对照菌株相比较,过表达gnd的重组菌株总脂肪酸含量提高了20%～30%,且6PGDH酶活力和gnd的转录水平也显著提高。由此可见,6PGDH在R. opacus PD630脂质合成中具有重要的作用,能为其提供所需的还原力NADPH,以促进其脂质的积累。     

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。     

Inhibitory effects of garcinol and pterostilbene on cell proliferation and adipogenesis in 3T3-L1 cells

The aim of this work was to study the effects of garcinol and pterostilbene on cell proliferation and adipogenesis in 3T3-L1 cells. The results showed that garcinol and pterostilbene decreased the cell population growth and caused cell cycle arrest at the G2/M phase in 3T3-L1 preadipocytes. During adipocyte differentiation, both garcinol and pterostilbene had inhibitory effects on fat droplet formation and triacylglycerol accumulation. The data indicated that garcinol and pterostilbene could inhibit the glycerol-3-phosphate dehydrogenase (GPDH) activity by 97.8 and 61.5%, respectively, as compared to the control. Both garcinol and pterostilbene significantly attenuated the protein expressions of PPARγ and C/EBPα during 3T3-L1 adipocyte differentiation. Moreover, garcinol and pterostilbene caused an inhibition of lipid accumulation in the 3T3-L1 adipocyte differentiation phase. Garcinol and pterostilbene also significantly up-regulated the gene expression of adiponectin as well as down-regulated the gene expressions of leptin, resistin, and fatty acid synthase (FAS) in 3T3-L1 adipocyte differentiation. In 3T3-L1 adipocytes, garcinol significantly down-regulated the protein expressions of PPARγ and FAS as well as up-regulated the protein expressions of adipose triglyceride lipase (ATGL) and adiponectin. Garcinol also significantly up-regulated the gene expression of adiponectin as well as down-regulated the gene expressions of leptin and FAS. These results suggest that garcinol and pterostilbene have anti-adipogenic effects on preadipocytes and adipocytes.     

黄大茶水提物改善高脂小鼠脂肪组织的脂肪酸代谢

目的：探究黄大茶水提物对高脂饮食小鼠脂肪组织脂肪酸代谢的调控机制。方法：将5 周龄雄性C57BL/6小鼠随机分为对照组、高脂饮食组、高脂饮食＋2.5%（终质量分数,下同）黄大茶水提取物组、高脂饮食＋0.5%黄大茶水提取物组。饮食干预处理12 周后,测定小鼠体质量、脂肪组织质量,观察脂肪组织形态,并分析脂肪酸代谢关键基因及蛋白表达量等指标。结果：2.5%黄大茶水提物能高度显著降低高脂小鼠体质量及脂肪组织质量（P＜0.001）;减少脂肪组织的脂质沉积;促进SREBP-1C、FAS、ACC、SCD-1等脂肪酸生成相关基因的表达,促进脂肪酸分解相关基因PGC-1α和CPT-1的表达;不同程度激活腺苷酸活化蛋白激酶（adenosine monophosphate activated protein kinase,AMPK）/乙酰辅酶A羧化酶（acetyl CoA-carboxylase,ACC）通路。结论：2.5%黄大茶水提物饮食干预能显著缓解高脂饮食小鼠肥胖和减少脂质沉积,促进脂肪组织脂肪酸合成和氧化分解代谢,此作用与黄大茶水提物激活AMPK/ACC通路相关。     

染料木黄酮抑制3T3-L1细胞成脂分化机制

目的：研究染料木黄酮是否通过雌激素受体介导影响3T3-L1前脂肪细胞成脂分化,并探讨其可能的机制。方法：以不同浓度染料木黄酮处理3T3-L1细胞,四甲基偶氮唑蓝（methyl thiazolyl tetrazolium,MTT）法测定细胞存活率;在3T3-L1前脂肪细胞成脂分化过程中分别加入不同浓度染料木黄酮、染料木黄酮和ICI182780（一种雌激素受体抑制剂）混合物及不同浓度雌二醇,油红染色观察分化结果,测定细胞甘油三酯（triglyceride,TG）含量;染料木黄酮、染料木黄酮和ICI182780混合物及不同浓度雌二醇处理诱导成熟后的脂肪细胞,测定培养液甘油含量;分别用染料木黄酮（30 μmol/L）、染料木黄酮（30 μmol/L）和ICI182780混合物干预细胞成脂分化,Western blotting法检测细胞外信号调节激酶（extracellular signal-regulated kinase,ERK）、p-ERK、腺苷酸活化蛋白激酶（adenosine monophosphate activated protein kinase,AMPK）、p-AMPK、激素敏感性脂肪酶（hormone sensitive lipase,HSL）、脂肪酸合成酶（fatty acid synthetase,FAS）蛋白表达量。结果：3T3-L1细胞存活率随染料木黄酮浓度的升高而降低,50～200 μmol/L染料木黄酮能抑制细胞生长（P＜0.01）;染料木黄酮能负向调节成脂分化后细胞胞浆内TG含量,在0～50 μmol/L浓度范围内呈剂量依赖关系,高剂量雌二醇（100 nmol/L）能下调TG含量;染料木黄酮能促进成熟脂肪细胞脂解,提高细胞培养液甘油浓度;染料木黄酮（30 μmol/L）能上调p-AMPK、HSL蛋白表达,下调FAS蛋白表达（P＜0.01）,对ERK、p-ERK、AMPK表达量无明显影响（P＞0.05）。ICI182780（1 μmol/L）能部分阻断染料木黄酮（30 μmol/L）对p-AMPK的调节作用（P＜0.05）。结论：染料木黄酮能抑制3T3-L1细胞成脂分化,其机制可能是染料木黄酮一方面下调FAS蛋白表达,抑制脂肪合成,另一方面激活AMPK-HSL途径促进脂肪分解;染料木黄酮还可能通过非雌激素受体途径抑制3T3-L1细胞成脂分化。     

Pomegranate husk extract,punicalagin and ellagic acid inhibit fatty acid synthase and adipogenesis of 3T3-L1 adipocyte

Fatty acid synthase (FAS) has been recognized as a potential therapeutic target for obesity. In this study, for the first time, the inhibitory effect of pomegranate husk extract, punicalagin and ellagic acid on FAS was investigated. We found them potently inhibiting the activity of FAS with half-inhibitory concentration values (IC₅₀) of 4.1 μg/ml (pomegranate husk extract), 4.2 μg/ml (4.50 μM, punicalagin) and 1.31 μg/ml (4.34 μM, ellagic acid), respectively. Moreover, they all exhibited time-dependent inactivation of FAS. Punicalagin and ellagic acid inhibited FAS with different mechanisms compared to previously reported inhibitors, through inactivating acetyl/malonyl transferase and β-ketoacyl synthase domains, respectively. Additionally, 100 μg/ml pomegranate husk extract, 5.24 μg/ml (5 μM) punicalagin and 4.5 μg/ml (15 μM) ellagic acid effectively reduced lipid accumulation inside FAS over-expressed 3T3-L1 adipocytes. Since FAS plays a key role in the biosynthesis pathway of fatty acid, these findings suggest that pomegranate husk extract, punicalagin and ellagic acid have potential in the prevention and treatment of obesity.     

Regulation of lipid and glucose homeostasis by mango tree leaf extract is mediated by AMPK and PI3K/AKT signaling pathways

Ethanolic extract of Mangifera indica (mango) dose-dependently decreased serum glucose and triglyceride in KK-A^y mice. Our in vitro and in vivo investigations revealed that the effect of mango leave extract (ME) on glucose and lipid homeostasis is mediated, at least in part, through the PI3 K/AKT and AMPK signaling pathway. ME up-regulated the expression of PI3 K, AKT and GYS genes by 2.0-fold, 3.2-fold, and 2.7-fold, respectively, leading to a decrease in glucose level. On the other hand, ME up-regulated AMPK and altered lipid metabolism. ME also down-regulated ACC (2.8-fold), HSL (1.6-fold), FAS (1.8-fold) and PPAR-γ (4.0-fold). Finally, we determined that active metabolites of benzophenone C-glucosides, Iriflophenone 3-C-β-glucoside and Foliamangiferoside A from ME, may play a dominant role in this integrated regulation of sugar and lipid homeostasis.     

Evaluation of hypolipidemic effects of peanut skin-derived polyphenols in rats on Western-diet

The effect of water soluble polyphenolic extract of peanut skin (PE) was investigated for its hypolipidemic properties in rats on Western diet. Seven-weeks old Wistar rats received control diet (AIN-93G), Western diet with and without a bolus of PE five times a week for 10weeks. Group which received 300mg/kg body weight showed significantly reduced body weight and epididymal fat. Plasma and liver triglyceride (TG) and cholesterol (TC) levels were significantly reduced while faecal secretion of TG and TC was greatly increased upon PE administration. Liver mRNA expression of enzymes involved in fatty acid synthesis, such as fatty acid synthase (FAS), sterol receptor element binding protein (SREBP)-1c, acetyl-CoA carboxylase (ACC1) and lipid uptake genes, such as PPARγ, were decreased, while PPARα was up-regulated by administration of PE. These data suggest that administration of PE may contribute to the improved lipid homoeostasis in rats on diets high in cholesterol and lipids.