金雀异黄素对PCOS大鼠卵巢和子宫组织中P450arom mRNA的作用

目的:通过建立多囊卵巢综合征(PCOS)高雄血症动物模型,观察金雀异黄素(GEN)对大鼠卵巢组织中雌雄激素转换关键酶P450芳香化酶(P450arom)的影响。方法:按照胰岛素(INS)联合HCG造模法建立实验动物模型,分为阴性对照组、模型组、GEN低、中、高剂量组及雌激素阳性对照组,其中剂量组分别灌胃GEN 5,10,20 mg/(kg体质量),雌激素组给予己烯雌酚0.5 mg/kg,持续15 d,观察动情周期10 d。实验结束后,取大鼠血液、子宫和卵巢,ELISA方法测定大鼠血清中雌二醇(E2)、睾酮(T)水平,并计算E2/T比值。RT-PCR法测定大鼠子宫和卵巢中P450arom m RNA表达情况。结果:与模型组相比,中、高剂量组及雌激素组大鼠血清E2水平上升,差异显著(P0.05);各GEN剂量组大鼠血清睾酮水平下降,差异不显著(P0.05);各GEN剂量组及雌激素组E2/T比值升高,差异显著(P0.05)。与模型组相比,高剂量组大鼠卵巢和子宫中P450arom m RNA水平下降明显(P0.05),差异显著;中、低剂量组大鼠卵巢和子宫中P450arom m RNA水平也呈下降趋势,差异不显著(P0.05)。结论 :不同剂量GEN可通过升高大鼠血清E2/T比值,拟补芳香化酶芳香化的缺陷;高剂量【20 mg/(kg体质量)】金雀异黄素可使PCOS大鼠卵巢和子宫组织中P450arom m RNA表达量显著升高,其效果与雌激素相近。     

大豆异黄酮对青年雌性大鼠卵巢、子宫组织中Bcl-2 mRNA 和Bax mRNA 表达的影响

目的：通过动物实验研究,观察Bcl-2 mRNA 和Bax mRNA 在青年雌性大鼠卵巢和子宫组织中的表达情况,从细胞凋亡角度研究大豆异黄酮对青年雌性大鼠的抗衰老作用。方法：选用2 月龄青年雌性大鼠50 只,按体质量分成5 组,每组10 只,分别为对照组(基础饲料)、低剂量组(大豆异黄酮100mg/(kg bw·d))、中剂量组(大豆异黄酮200mg/(kg bw·d))、高剂量组(大豆异黄酮300mg/(kg bw·d))、雌激素组(己烯雌酚0.5mg/kg 饲料),实验周期7 周。采用原位杂交法检测各组大鼠卵巢和子宫组织中Bcl-2 mRNA 和Bax mRNA 的表达水平。结果：大豆异黄酮能够增强大鼠卵巢和子宫组织中Bcl-2 mRNA 的表达水平;而各剂量组大鼠卵巢和子宫组织中Bax mRNA水平呈下降趋势。结论：大豆异黄酮可以增强抗凋亡基因Bcl-2 mRNA,拮抗促凋亡基因Bax mRNA 的水平,推测这是大豆异黄酮对青年雌性大鼠发挥抗衰老作用的途径之一。     

金雀异黄素对围绝经期小鼠卵巢和子宫组织中芳香化酶和FSHR的调控作用

目的:研究金雀异黄素对围绝经期模型小鼠卵巢和子宫组织中芳香化酶P450及促卵泡成熟激素受体(FSHR)的调节作用。方法 :选择12月龄自然衰老ICR小鼠作为围绝经期动物模型,分为对照组(CG),Gen低(L-Gen)、中(M-Gen)、高剂量组(H-Gen)及雌激素组(EG)。剂量组分别灌胃金雀异黄素(Gen)15,30,60 mg/kg,雌激素组灌胃戊酸雌二醇0.5 mg/kg,持续8周。RT-PCR及荧光定量PCR法测定小鼠卵巢和子宫中P450arom mRNA,CYP19 mRNA和FSHR的表达水平。结果 :与对照组相比,H-Gen和EG小鼠P450arom mRNA,CYP19mRNA和FSHR的表达量均升高,差异显著(P0.05)。结论 :金雀异黄素(60 mg/kg)可使小鼠卵巢与子宫中P450arom mRNA,CYP19 mRNA和FSHR的表达量升高,雌激素作用显著,揭示金雀异黄素可通过调节芳香化酶和促卵泡成熟激素受体基因来改善围绝经期卵巢与子宫的功能。     

大豆异黄酮对青年雌性大鼠的抗氧化作用研究

目的:研究大豆异黄酮对青年雌性大鼠的抗氧化作用并检验其安全性。方法:选用2月龄青年雌性大鼠50只,按体重随机分成5组,每组10只,分别为空白对照组(基础饲料);低(L-SI)、中(M-SI)、高剂量组(H-SI),其大豆异黄酮含量分别为100、200、300 mg/kg bw;雌激素组(EC,己烯雌酚0.5 mg/kg),实验周期为7周。观察各组大鼠实验前、后血清中超氧化物歧化酶(SOD)、过氧化氢酶(CAT)、丙二醛(MDA)和谷胱甘肽过氧化物酶(GSH-PX)等活力变化以及子宫雌激素受体(ER-α)含量的变化,并做病理组织学检查,检验其安全性。结果:大豆异黄酮可显著提高各剂量组SOD活力(p0.05);低、中剂量组CAT活力升高显著,有显著性差异(p0.05),而在高剂量组没有显著差异;显著降低大鼠MDA含量;对GSH-PX活性的作用不显著。大豆异黄酮可上调大鼠子宫ER-α含量。高剂量组大鼠卵巢发生病理变化。结论:大豆异黄酮可增强青年雌性大鼠的抗氧化能力,其在100~200 mg/kg bw剂量范围对大鼠无不良影响;而当剂量为300mg/kg bw时,对青年雌性大鼠的卵巢产生负面作用。     

金雀异黄素通过AMPK/SIRT1/PGC-1α信号通路缓解免疫抑制大鼠的疲劳作用

目的：探讨金雀异黄素（genistein,GEN）缓解免疫抑制大鼠的疲劳作用及其作用机制。方法：96 只雄性SD大鼠随机分为6 组（每组16 只）,分别为空白对照组、免疫抑制模型组与金雀异黄素低、中、高剂量组以及阳性对照组。除空白对照组外,其余组腹腔注射环磷酰胺40 mg/kg mb,连续3 d,建立免疫抑制大鼠模型。金雀异黄素低、中、高剂量组分别灌胃10、20、40 mg/kg mb金雀异黄素,阳性对照组灌胃贞芪扶正颗粒3.125 g/kg mb,空白对照组灌胃等量花生油。实验结束后,记录大鼠力竭游泳时间;采用比色法检测大鼠血清中肌酸激酶（creatine kinase,CK）、乳酸脱氢酶（lactate dehydrogenase,LDH）活力;酶联免疫吸附测定法检测大鼠血清中免疫球蛋白G（immunoglobulin G,IgG）、肿瘤坏死因子α（tumor necrosis factor α,TNF-α）质量浓度;采用实时荧光定量技术检测大鼠骨骼肌中腺苷酸活化蛋白激酶（adenosine monophosphate-activated protein kinase,AMPK）、沉默信息调节因子1（silent information regulator 1,SIRT1）、过氧化物酶增殖活化受体γ辅激活因子1α（peroxisome proliferator-activated receptor γ coactivator 1α,PGC-1α）和过氧化物酶体增殖物激活受体γ（peroxisome proliferators-activated receptor γ,PPARγ）mRNA表达水平;采用蛋白免疫印迹法检测大鼠骨骼肌中p-AMPK、SIRT1、PGC-1α和PPARγ的蛋白表达水平。结果：与免疫抑制模型组相比,补充GEN后极显著延长了大鼠力竭游泳时间（P＜0.01）;与免疫抑制模型相比,高剂量GEN能够显著降低血清中CK活力（P＜0.05）和LDH活力（P＜0.01）,极显著提高大鼠血清中IgG、TNF-α质量浓度（P＜0.01）,同时显著提高大鼠骨骼肌中p-AMPK、SIRT1、PGC-1α和PPARγ基因及蛋白表达水平（P＜0.05、P＜0.01）。结论：GEN具有缓解免疫低下大鼠疲劳的作用,其机制可能与激活骨骼肌AMPK/SIRT1/PGC-1α信号通路及改善大鼠运动耐力、能量产生及免疫调节能力有关。     

大豆异黄酮对青年雌性大鼠的副作用研究

选用3月龄青年雌性大鼠60只,按体质量随机分成5组,每组12只,分别为空白对照组,低、中、高剂量组和雌激素组,实验周期6周.进行病理组织学检查.检验其安全性.实验结果表明,大豆异黄酮对青年雌性大鼠体质量的影响不显著,脏体比结果表明对脾脏可能有一定的影响.从而可能影响其免疫功能.病理检测结果表明,高剂量组大鼠的卵巢发生了病理变化,肝脏、肾脏及脾脏的病理变化不明显,推测在300 mg/kg·bw 的剂量下,大豆异黄酮可能会对青年雌性大鼠卵巢产生影响.     

辣椒素剂量对去势雌性大鼠血脂、肝脂及盲肠内环境的影响

目的：探讨辣椒素剂量对去势雌性大鼠血脂、肝脂及盲肠内环境的影响。方法：选用30 只雌性SD大鼠随机分组为5 组,其中1 组大鼠进行伪切除手术作对照（伪切除组）,另外4 组大鼠做双侧卵巢切除手术,基础饲料喂养恢复1 周后,分为不灌胃辣椒素（空白组）和灌胃5.0、10.0、15.0 mg/（kg·d）辣椒素剂量组（低、中、高剂量组）。喂食相同基础饲料28 d后解剖,测定大鼠血清和肝脏中胆固醇、甘油三酯含量及盲肠面积,盲肠内容物水分含量、pH值、短链脂肪酸和微生物等指标。结果：空白组大鼠的体质量、采食量、血脂、肝脏总脂肪、总胆固醇、甘油三酯总含量均显著高于伪切除组。辣椒素可降低双侧卵巢切除大鼠的体质量增加量、血清和肝脏中胆固醇和甘油三酯含量,且具有明显的剂量关系;同时可以降低盲肠组织总质量、盲肠体质量比、盲肠内容物短链脂肪酸含量,显著降低盲肠内容物有益菌数量（P＜0.05）;辣椒素可以显著升高游离氨含量和pH值,增加有害菌数量（P＜0.05）,但辣椒素各剂量组之间没有显著性差异。结论：辣椒素对因雌激素缺乏引起高脂血症雌性大鼠具有较好的降血脂、降肝脂作用,但对盲肠内环境具有一定的损伤作用。     

花椒精对卵巢切除大鼠脂质代谢的影响

目的：探讨花椒精对卵巢切除大鼠脂质代谢的影响。方法：将40 只雌性Sprague-Dawley（SD）大鼠随机分为5 组,其中1 组进行伪切除手术（Sham）作为对照组,另外4 组进行双侧卵巢切除手术（ovariectomy,OVX）,恢复饲喂一周后,分为空白组和灌胃花椒精高（15 mg/kg）、中（10 mg/kg）、低（5 mg/kg）剂量组。灌胃4 周后解剖,检测大鼠血脂、肝脂及小肠和粪便中胆汁酸含量等指标。结果：灌胃花椒精可降低血清中甘油三酯（triglyceride,TG）、总胆固醇（total cholesterol,TC）、低密度脂蛋白胆固醇（low density lipoproteincholesterin,LDL-C）和非高密度脂蛋白胆固醇（non-high density lipoprotein cholesterol,non-HDL-C）的浓度（p＜0.05）,升高HDL-C的浓度;降低肝脏中脂肪、TC、TG的含量（P＜0.05）;增加大鼠排便量、促进小肠内容物和粪便中胆汁酸以及粪醇、胆固醇等中性固醇的排泄,且存在明显的剂量效应。结论：花椒精可改善卵巢切除SD大鼠因雌性激素缺乏而引起的高脂血症,可能与促进胆汁酸和中性固醇的排泄有关。     

蓝靛果花色苷对高脂血症大鼠肝脏内与胆固醇代谢相关基因的作用

目的：研究蓝靛果花色苷对高脂血症大鼠肝脏肝X受体（liver X receptor α,LXRα）、B族I型清道夫受 体（scavenger receptor class B, type I,SR-BI）、三磷酸腺苷结合盒转运蛋白G5（ATP-binding cassette transporter G5,ABCG5）、过氧化物酶体增殖物激活受体（peroxisome proliferator-activated receptor γ,PPARγ）及胆固醇7α-羟化 酶（cholesterol 7α-hydroxylase,CYP7a1）基因表达的影响。方法：选择2 月龄雄性Wistar大鼠60 只,将大鼠随机分为 6 组,其中10 只给予普通饲料,其余50 只给予高脂饲料。30 d造模成功后,分别建立基础饲料正常对照组（ND, 灌胃1.2 g/（kg·d）生理盐水）、高脂模型对照组（HFD,灌胃1.2 g/（kg·d）生理盐水）、阳性对照组（灌 胃10 mg/（kg·d）辛伐他汀片）和蓝靛果花色苷低（HFD＋L）、中（HFD＋M）、高（HFD＋H）剂量组（分别灌 胃4.0、40.0、120.0 mg/（kg·d）蓝靛果花色苷）,持续28 d。利用实时荧光定量聚合酶链式反应检测大鼠肝脏组 织中LXRα、SR-BI、ABCG5、PPARγ及CYP7a1 mRNA的表达情况。结果：经蓝靛果花色苷干预后,与HFD组相比： 蓝靛果花色苷各剂量组肝脏中SR-BI、ABCG5 mRNA表达几乎不受影响,且无显著性差异（P＞0.05）;HFD＋M、 HFD＋H组LXRα、CYP7a1 mRNA表达升高且差异极显著（P＜0.01）;HFD＋L、HFD＋M、HFD＋H组 PPARγ mRNA表达降低且差异极显著（P＜0.01）。结论：蓝靛果花色苷通过提高高脂血症大鼠肝脏内LXRα、 CYP7a1 mRNA表达,降低PPARγ mRNA表达来调节高脂血症大鼠的血脂水平,预防动脉硬化的发生。 关键词：蓝靛果;蓝靛果花色苷;高脂血症大鼠;肝X受体;B族I型清道夫受体;三磷酸腺苷结合盒转运蛋白G5; 过氧化物酶体增殖物激活受体γ;胆固醇7α-羟化酶     

大豆异黄酮降血脂作用的研究

目的：观察大豆异黄酮对高脂血症大鼠血脂的影响.方法：选择成年雌性SD大鼠50只,体重280～320g,随机分为四组：空白对照组：喂饲基础饲料;高脂模型组：喂饲高脂饲料;其余2组分别喂饲添加300、600mg/kg大豆异黄酮的高脂饲料.实验第6周末,空腹12h,5%戊巴比妥钠麻醉后,心脏取血及制备10%肝组织匀浆,测定血清总胆固醇（TC）、甘油三脂（TG）、高密度脂蛋白（HDL-C）、低密度脂蛋白（LDL-C）、脂蛋白脂酶（LPL）、肝脂酶（HL）等指标.结果：与高脂组比较,SI剂量组大鼠肝脏中的TC、TG、LDL-C显著降低（p＜0.01）,HDL-C显著增高（p＜0.05）,LPL活性显著增强（p＜0.05）.结论：大豆异黄酮具有明显的降血脂作用.     

Increased exposure of vitamin A by Chrysanthemum morifolium Ramat extract in rat was not via induction of CYP1A1, CYP1A2, and CYP2B1

The aim of this study was to investigate the effect of Chrysanthemum morifolium Ramat (CM) extract on the pharmacokinetics of retinol and activities of cytochrome P450s (CYP450s) related to retinoid metabolism. Rats were treated with CM extract for 15 d. Plasma concentrations of retinol were measured following oral administration of retinol (45 mg/kg). Basal levels of retinol and retinoic acid in serum and liver were also measured. 7-Ethoxyresorufin-O-deethylase activity, phenacetin-O-deethylase activity, and 7-pentoxyresorufin-O-deethylase activities were used to assay the activities of CYP1A1, CYP1A2, and CYP2B1 in hepatic microsomes of rats, respectively. Protein expressions of the 3 CYP450s were measured by western blot. Our studies demonstrated that CM extract dose-dependently increased basal level of retinol in serum. In pharmacokinetic experiment, CM extract dose-dependently increased plasma concentrations of retinol after oral administration of retinol to rats treated with CM extract. But activities and expressions of CYP1A1, CYP1A2, and CYP2B1 in hepatic microsomes of rats were also induced by CM extract.     

兰坪虫草的缓解运动疲劳功能

目的：研究兰坪虫草对小鼠运动的抗疲劳效果。方法：小鼠随机分为5 个实验组,分别为兰坪虫草低剂量组（450 mg/（kg·d））、中剂量组（900 mg/（kg·d））、高剂量组（1 800 mg/（kg·d））以及空白组（蒸馏水）、阳性对照组（西洋参600 mg/（kg·d））,连续灌胃30 d,研究兰坪虫草对小鼠负重游泳时间、血乳酸、血清尿素氮、肝糖原、抗氧化酶、血液相关参数等疲劳指标的影响。结果：各剂量组兰坪虫草均能显著延长小鼠负重游泳时间（P＜0.05）;中、高剂量组可以显著降低小鼠运动后血清尿素氮浓度（P＜0.05）;高剂量组和阳性对照组能显著提高小鼠体内肝糖原的储备量（P＜0.05）;同时,兰坪虫草能提高血液血红蛋白和血糖浓度,明显增加抗氧化酶的活力,降低丙二醛水平。结论：研究证明兰坪虫草具有缓解小鼠运动疲劳的作用。     

蓝靛果花色苷对高脂血症大鼠肝脏LDLR、ABCG1及ABCA1基因表达的影响

目的：研究蓝靛果花色苷对高脂血症大鼠肝脏低密度脂蛋白受体（low density lipoprotein receptor, LDLR）、三磷酸腺苷结合盒转运体G1（ATP-binding cassette transporter G1,ABCG1）及ABCA1基因表达的影响。 方法：选择2 月龄雄性Wistar大鼠60 只,将大鼠随机分为6 组,分别为基础饲料对照组（ND,1.2 g/（kg·d mb） 生理盐水灌胃）、高脂模型对照组（HFD,1.2 g/（kg·d mb）生理盐水灌胃）、阳性对照组（10 mg/（kg·d mb） 辛伐他汀片灌胃）,蓝靛果花色苷低、中、高剂量组（HFD＋L、HFD＋M、HFD＋H,分别给予4.0、40.0、 120.0 mg/（kg·d mb）的花色苷灌胃）,持续28 d。实验结束后,测定血清总胆固醇（total cholesterol,TC）、 甘油三酯（triglyceride,TG）、高密度脂蛋白胆固醇（high density lipoprotein cholesterol,HDL-C）、低密 度脂蛋白胆固醇（low density lipoprotein cholesterol,LDL-C）、载脂蛋白A（apolipoprotein A,Apo-A）及载 脂蛋白B（Apo-B）等血脂指标水平。取大鼠肝脏,利用实时荧光定量聚合酶链式反应测定大鼠肝脏组织中 LDLR、ABCG1、ABCA1 mRNA表达量,Western blot检测LDLR蛋白表达水平。结果：蓝靛果花色苷干预后, 与HFD组相比,花色苷均能不同程度地降低高血脂大鼠血清中TC、TG、LDL-C、Apo-B的含量（P＜0.05或 P＜0.01）,显著升高HDL-C及Apo-A的含量（P＜0.05或P＜0.01）。花色苷各剂量组LDLR蛋白和mRNA水平均增 高,与HFD组比较差异有显著性（P＜0.05）,ABCA1 mRNA和ABCG1 mRNA的表达水平也高于HFD组,尤其是花 色苷中、高剂量组差异明显（P＜0.05）。结论：40.0 mg/（kg·d mb）蓝靛果花色苷具有明显的调节血脂作用,其 作用机制可能是通过上调肝脏LDLR和ABC家族基因的表达,进而调节胆固醇逆转运过程。     

Practical application of mammalian cytochrome P450

Heterologous expression systems play an important role in the analysis of structure-function relationships of mammalian P450s. In addition, these expression systems allow practical application of mammalian P450s. Genetically engineered fused enzymes between mammalian P450 and yeast NADPH-P450 reductase have possible applications in bioconversion processes. Combined use of techniques reported thus far could produce steroid hormones in the recombinant yeast cells harboring four P450 species, CYP11A1, CYP17A1, CYP21B1 and CYP11B1. In an Escherichia coli expression system, the technology of the construction of the mitochondrial P450 electron transport chain has been established. The recombinant E. coli cells expressing CYP27B1, adrenodoxin and NADPH-adrenodoxin reductase would be applicable to a bioconversion process to produce 1alpha,25-dihydroxyvitamin D3. We also demonstrated the usefulness of heterologous expression systems for human liver microsomal P450s for the prediction of drug metabolism in the human body. Microsomal fractions prepared from recombinant yeast, insect and mammalian cells are commercially available and play an important role in preclinical drug development. Application of mammalian P450 to bioremediation with genetic engineering has also been developed. Thus, mammalian P450s appear to have great potential for a wide range of practical applications.     

Potent inhibition of human cytochrome P450 3A4, 2D6, and 2C9 isoenzymes by grapefruit juice and its furocoumarins

ABSTRACT:  The cytochrome P450 enzyme family is the most abundant and responsible for the metabolism of more than 60% of currently marketed drugs and is considered central in many clinically important drug interactions. Seven different grapefruit and pummelo juices as well as 5 furocoumarins isolated from grapefruit juice were evaluated at different concentration on cytochrome P450 3A4 (CYP3A4), cytochrome P450 2C9 (CYP2C9), and cytochrome P450 2D6 (CYP2D6) isoenzyme activity. Grapefruit and pummelo juices were found to be potent inhibitors of cytochrome CYP3A4 and CYP2C9 isoenzymes at 25% concentration, while CYP2D6 is inhibited significantly low at all the tested concentration of juices ( P < 0.05). Among the 5 furocoumarins tested, the inhibitory potency was in the order of paradisin A > dihydroxybergamottin > bergamottin > bergaptol > geranylcoumarin at 0.1 μM to 0.1 mM concentrations. The IC₅₀ value was lowest for paradisin A for CYP3A4 with 0.11 μM followed by DHB for CYP2C9 with 1.58 μM.     

Effect of a high cornstarch diet on hepatic cytochrome P450 2C and 3A activity and progesterone half-life in dairy cows

In the cow, inadequate concentrations of progesterone during gestation may lead to an abrupt termination of pregnancy. The primary organ involved in progesterone catabolism is the liver, which contains an abundance of cytochrome P450 isozymes (EC 1.14.14.1; mixed-function monooxygenases). The objectives of the current experiment were to determine the effect of feeding 2 isoenergetic and isonitrogenous diets, formulated to cause divergent insulin secretion, on hepatic cytochrome P450 2C (CYP2C) and 3A (CYP3A) activity as well as the resulting biological half-life of progesterone. Twenty-two Holstein cows averaging 80 ± 7 d in milk were randomly assigned to either a high cornstarch diet or a high fiber diet in a crossover experimental design consisting of two 14-d periods. Dry matter intake, milk yield, milk lactose yield, and milk lactose percentage were similar between the 2 diets. Milk fat yield and milk fat percentage were higher in cows fed the high fiber diet, whereas milk protein yield tended to be higher and milk protein percentage was higher in cows fed the high cornstarch diet. Energy balance tended to be improved by 57% in cows consuming the high cornstarch diet. Insulin concentrations at the time of liver biopsy (3.16 ± 0.04 h post-feeding) were increased by 44% in cows consuming the high cornstarch diet compared with cows consuming the high fiber diet. Cytochrome P450 2C activity was decreased by 45%, whereas CYP3A activity tended to be lowered by 34% in cows consuming the high cornstarch diet. Cytochrome P450 2C mRNA expression tended to be decreased by 21% in cows fed the high cornstarch diet, whereas CYP3A mRNA expression was not different between the dietary treatments. The fractional rate constant of progesterone decay was not different between the 2 diets; however, the half-life of progesterone tended to be longer in cows fed the high cornstarch diet compared with cows fed the high fiber diet (85 vs. 64 min, respectively). In summary, cows consuming the high cornstarch diet had increased insulin concentrations and lower hepatic CYP2C and CYP3A activity and tended to have a longer progesterone half-life compared with cows consuming the high fiber diet. Feeding diets that stimulate insulin secretion could alter progesterone clearance during lactation, when dairy cows have increased rates of progesterone inactivation because of high energy demands and increased DMI.     

藤黄果提取物对雄性大鼠脂代谢的影响及降脂机理

以雄性大鼠为研究对象,探讨日粮中添加不同剂量的藤黄果提取物对大鼠脂代谢常规生化指标及相关基因表达的影响。结果表明：日粮中添加不同剂量的藤黄果提取物均可显著降低大鼠血清中甘油三酯的含量（P＜0.05）,高剂量藤黄果提取物则可显著降低肝脏组织中甘油三酯的含量（P＜0.05）;不同剂量藤黄果提取物处理对血清和肝脏组织中总胆固醇含量均无显著影响（P＞0.05）。脂肪代谢相关基因分析结果表明：高剂量藤黄果提取物处理可显著抑制SREBP1c（P＜0.01）和ACL（P＜0.05）基因表达水平,同时显著提高ACO和ATGL基因表达水平（P＜0.05）;MCD和PPARα基因表达水平在中剂量（P＜0.05）和高剂量（P＜0.01）藤黄果提取物处理组显著高于对照组;高剂量藤黄果提取物处理可显著促进AMPKα1和AdipoR-1基因表达水平（P＜0.05）,但对脂联素基因表达水平没有影响。以上结果提示,藤黄果提取物处理可通过激活Adipo-AMPK信号通路,进而抑制脂肪酸合成途径中的关键因子、增强脂肪酸氧化途径中的关键因子基因的表达,最终降低雄性大鼠体内脂肪的沉积。     

The use of Yarrowia lipolytica for the expression of human cytochrome P450 CYP1A1

Cytochromes P450 constitute a superfamily of haem-thiolate mono-oxygenases that are involved in the oxidative metabolism of lipophilic subtrates. These enzymes require association with cytochrome P450 reductase (CPR) to achieve optimal activities. We have expressed human cytochrome P450 CYP1A1 under the POX2 promoter (pPOX2-CYP1A1) in Y. lipolytica, with or without overproduction of Y. lipolytica CPR expressed under the ICL promoter (pICL-CPR) or the POX2 promoter (pPOX2-CPR). Activity of cytochrome CYP1A1 was analysed by conversion of hydroxyresorufin to resorufin. Strain JMY330 and JMY330-CPR present no activity, the monocopy cytochrome CYP1A1 integrant JMY331 and JMY331-CPR derivatives present an average activity of 32.0 pM/min/dw and 48.3 and 64.6 pM/min/dw for pICL-CPR and pPOX2-CPR, respectively. Increase of CPR expression resulted in about two-fold higher activity. The multicopy 1A1 integrant JMY339 and JMY339-CPR derivatives present an activity of 129 pM/min/dw and 815-1845 pM/min/dw, respectively. Increase of CPR expression resulted in 6.3-12.8-fold higher activity, depending on the CPR transformant. We observed a 50-fold increase of activity between the monocopy integrant JMY331 as compared to the multicopies integrant JMY339-CPR in which CPR was overexpressed.