白蔹配伍乌头对大鼠肝脏CYP450的调节作用

［摘要］目的研究乌头、白蔹配伍对主要药物代谢酶CYP1A2、CYP2E1、CYP3A1/2在酶活性、mRNA水平和蛋白质水平的影响。方法采用高效液相色谱法测定CYP1A2、CYP2E1活性；采用紫外 可见分光光度法测定CYP3A1/2活性；分别采用逆转录 聚合酶链反应（RT PCR）和Western Blot方法评价药物对CYP1A2、CYP2E1、CYP3A1、CYP3A2 mRNA及蛋白水平的影响。结果乌头、白蔹配伍后CYP1A2、CYP2E1、CYP3A1/2的酶活性均有下降；Western Blot检测显示CYP1A2、CYP3A1的蛋白质表达水平上升；CYP2E1、CYP3A2的蛋白质表达水平下降。RT PCR检测显示CYP1A2、CYP2E1、CYP3A1、CYP3A2的mRNA水平均上升。结论乌头、白蔹配伍后抑制CYP1A2、CYP2E1、CYP3A1/2的酶活性，CYP2E1酶活性下降可能主要通过影响基因转录进而影响其蛋白水平来实现；CYP1A2、CYP3A1/2酶活性下降则与基因和蛋白水平不相关。     

甘草与海藻提取液合用对CYP3A1/2酶活性及mRNA表达的影响

目的:研究甘草与海藻提取液合用对CYP3A1/2酶活性的影响及在mRNA水平的调控作用。方法:采用紫外-可见分光光度法测定CYP3A1/2活性;采用RT-PCR评价药物对CYP3A1、CYP3A2 mRNA水平的影响。结果:甘草、海藻提取液合用后诱导了CYP3A1/2的酶活性;合用后诱导CYP3A1、CYP3A2 mRNA表达。结论:甘草、海藻提取液合用后诱导CYP3A1/2酶活性,酶活性增强可能主要由诱导其mRNA水平来实现。     

甘草与海藻 大戟 芫花配伍对大鼠肝脏CYP2E1酶活性及mRNA表达的影响

目的研究甘草与海藻、大戟、芫花合用对CYP2E1酶活性的影响及在mRNA水平的调控作用。方法采用高效液相色谱法测定CYP2E1活性;采用反转录聚合酶链反应(RT-PCR)评价药物对CYP2E1 mRNA水平的影响。结果甘草单用能明显诱导CYP2E1酶活性,与海藻、大戟、芫花合用后对CYP2E1酶活性的诱导作用没有甘草单用明显。CYP2E1 mRNA水平基本与酶活性水平相平行。结论甘草与海藻、大戟、芫花合用后诱导CYP2E1酶活性,酶活性变化可能主要通过影响基因转录来实现。     

地塞米松对大鼠肝脏微粒体细胞色素P-450的诱导效应

目的:观察地塞米松(dexamethasone,DEX)对细胞色素P-450(cytochrome P450,CYP450)的诱导效应,并探讨其诱导机制.方法:雄性Wistar大鼠分别以DEX 0,25,50和100mg·kg-1·d-1诱导处理(ip)4d后,测定大鼠肝脏总CYP450含量,CYP3A1,CYP3A2和CYP2B 1/2的mRNA及蛋白的表达水平,肝脏ERD(CYP3A活性),PROD(CYP2B活性)和BROD(总CYP450活性).结果:CYP450含量、ERD、PROD和BROD活性在DEX多次诱导后都有升高.CYP3A1 mRNA表达水平、蛋白含量和酶活性有明显的升高,剂量效应关系明显;CYP3A2蛋白明显升高,但mRNA表达水平却无明显变化.PROD和CYP2B1/2的mRNA表达水平以及总CYP450含量均在50mg·kg-1·d-1剂量组达到最高值.结论:DEX对雄性大鼠主要诱导CYP3A1和CYP3A2两个CYP450成员表达上调,对CYP2B1/2也有一定的诱导作用,其诱导作用主要表现在酶活性、酶蛋白含量和mRNA表达水平的升高.CYP3A1和CYP3A2的诱导方式可能不同.     

慢性间断性低氧对大鼠肝脏CYP3A_2和CYP2E_1的影响

目的:观察慢性间断性低氧对大鼠肝脏CYP3A2和CYP2E1的影响。方法:♂SD大鼠随机分为对照组和实验组,实验组分别低氧3、7、14、28d。采用酶法测定血清丙氨酸氨基转移酶(ALT)和天冬氨酸氨基转移酶(AST)活性,分光光度法测定大鼠肝微粒体红霉素N-脱甲基酶(ERD)、苯胺羟化酶(ANH)活性,半定量逆转录聚合酶链式反应(RT-PCR)检测大鼠肝脏细胞色素P4503A2、2E1的mRNA表达水平。结果:慢性间断性低氧对血清ALT和AST活性无明显影响;低氧7d后,大鼠肘脏ERD和ANH活性明显升高,28d时诱导率分别为155.5%和42.2%;同时CYP3A2和CYP2E1mRNA的表达水平也分别增加了220.5%和102.8%。结论:慢性间断性低氧能显著增加大鼠肝脏ERD(CYP4503A2)和ANH(CYP2E1)活性,其机制可能与其在转录水平上提高肝脏CYP4503A2和CYP2E1的基因表达水平有关。     

丁香酸和柠檬苦素对小鼠肝脏CYP450酶的影响

目的 研究丁香酸和柠檬苦素对小鼠肝脏细胞色素P450主要亚型mRNA及蛋白表达水平的影响.方法 C57BL/6小鼠随机分为空白对照组、丁香酸组、柠檬苦素组和苯巴比妥组,连续灌胃给药2周,末次给药后处死,提取小鼠肝脏总RNA及肝微粒体,荧光定量聚合酶链式反应(PCR)技术和蛋白质免疫印迹(Western blot)测定CYP450酶主要亚型mRNA和蛋白表达水平.结果 在mRNA水平上,丁香酸对Cyp1a2、Cyp2c37、Cyp2d9 mRNA表达没有明显作用,柠檬苦素对Cyp1a2 mRNA的表达有显著诱导作用;在蛋白水平上,丁香酸对CYP1A1、CYP1A2、CYP3A、CYP2D和CYP2E1蛋白的表达有明显的诱导作用,柠檬苦素对CYP1A1、CYP1A2、CYP2A、CYP2D和CYP2E1有显著的诱导,对CYP2B和CYP2C蛋白表达产生抑制作用.结论 丁香酸和柠檬苦素对细胞色素P450主要亚型均具有不同程度的诱导和抑制作用.     

Caspase抑制剂F1013对大鼠肝CYPs含量及其主要亚型mRNA表达的影响

目的:探讨Caspase抑制剂F1013对大鼠肝CYPs含量及其主要亚型CYP1A2,CYP2D1,CYP2E1,CYP2C11,CYP3A1 mRNA相对表达水平的影响。方法:Wistar大鼠40只,随机分成空白组、诱导剂组、F1013低、中、高剂量组。空白组和诱导剂组分别灌胃给予0.9%氯化钠溶液和地塞米松50 mg·kg-1.d-1,F1013低、中、高组分别肌内注射F1013 1.25,2.5,5.0 mg·kg-1.d-1,每日1次,连续6 d。取大鼠肝组织制备肝微粒体,测定微粒体蛋白浓度及CYP总酶含量。并采用实时定量荧光RT-PCR法分析大鼠CYP各主要亚型mRNA的相对表达水平。结果:F1013低、中、高组肝微粒体CYP总酶含量与空白组比有显著增高(P<0.05),提示该药对CYP总酶有诱导作用。低剂量组CYP2D1酶活性显著升高(为空白组2.54倍,P<0.05);中剂量组CYP1A2及CYP2E1酶活性显著升高,分别为空白组4.24和2.46倍(P<0.05);3个剂量的F1013对CYP2C11均无显著诱导作用。结论:F1013在1.25,2.5,5.0 mg.kg-1剂量范围内,可显著诱导CYP总酶活性。F1013 1.25 mg·kg-1可诱导CYP 2D1 mRNA表达,2.5 mg·kg-1剂量可诱导CYP1A2及CYP2E1 mRNA的表达,其诱导机制可能与升高各主要亚酶mRNA相对表达水平有关。     

基于CYP3A4酶探讨灯盏花素对洛伐他汀的药动学的影响及机制

目的 探究灯盏花素与洛伐他汀联用对大鼠体内药动学的影响,从代谢酶的角度揭示灯盏花素对洛伐他汀药动学产生影响的机制。方法 采用探针药物法及RT-HPLC法测定咪达唑仑在肝微粒体孵育体系中的浓度,评价灯盏花素与洛伐他汀联用对CYP3A4酶活性的影响。通过RT-PCR反应来检测CYP3A4酶mRNA基因表达,采用Western blot法,从蛋白翻译水平上分析灯盏花素与洛伐他汀联用对大鼠肝脏CYP3A4蛋白表达的影响。结果 洛伐他汀与灯盏花素联合用药后,洛伐他汀在大鼠体内的血药浓度显著升高,从0.39 mg?L-1 上升到1.08 mg?L-1 ,清除率从3.36L?h-1?kg-1降低到1.08L?h-1?kg-1,药物半衰期从5.0h延长到6.2h,联合给药后洛伐他汀的AUC从2.42mg?L-1?h-1上升到4.22mg?L-1?h-1。洛伐他汀组与空白组比较CYP3A4酶活性均没有明显变化;灯盏花素组及灯盏花素联合洛伐他汀组与空白组比较发现均抑制CYP3A4酶活性;灯盏花素与灯盏花素联合洛伐他汀组CYP3A4酶mRNA 表达量均较空白组显著降低;CYP3A4酶蛋白含量结果表明,洛伐他汀组与灯盏花素联合洛伐他汀组与空白组比较CYP3A4酶蛋白含量均没有明显变化。结论 洛伐他汀与灯盏花素联用,灯盏花素通过抑制其基因转录水平抑制CYP3A4的活性,使大鼠体内药动学过程发生变化,洛伐他汀药物的代谢减慢。     

马钱子碱与甘草次酸、甘草苷配伍后对大鼠肝脏CYP450的影响(英文)

马钱子碱每日低、中、高(3,15和60 mg·kg-1)剂量以及高剂量马钱子碱和甘草次酸(每日25 mg·kg-1)、甘草苷(每日20 mg·kg-1)配伍,分别对Wistar大鼠连续灌胃给药7天后,检测不同给药组对CYP3A、CYP1A2、CYP2E1和CYP2C的酶活性和mRNA表达的影响。与对照组相比,高剂量马钱子碱使CYP3A活性下降24.5%,CYP2C的活性下降34.6%,而使CYP2E1的活性提高了146.1%。另一方面,与高剂量组相比,甘草次酸配伍组使CYP2E1的活性降低了51.4%,CYP1A2的活性降低了33.5%;甘草苷配伍组使CYP2E1的活性降低了41.1%,CYP2C的活性降低了37.7%。实验结果表明,马钱子碱和甘草次酸、甘草苷配伍后,可以在一定程度上影响上述CYP450酶的mRNA表达和酶活性。因此推测配伍后甘草苷对马钱子碱所致CYP450酶异常变化的拮抗作用,以及甘草次酸对CYP2E1和CYP1A2活性的抑制作用,可能是甘草降低马钱子毒性的重要机制之一。     

中药莪术激活PXR及对大鼠肝细胞色素P450 3A的影响

目的考察莪术能否通过体外激活PXR调节细胞色素P4503A4(CYP3A4)的转录表达及对大鼠肝脏CYP3A在酶活性及mRNA表达的诱导作用。方法在HepG2细胞中,采用瞬时共转染报告基因实验研究莪术对PXR介导的CYP3A4的转录调节作用;在大鼠体内,采用紫外分光光度法和RT-PCR技术检测莪术对大鼠肝脏CYP450含量及CYP3A同工酶红霉素N-脱甲基酶(ERD)的活性和CYP3A基因mRNA表达的影响。结果在体外报告基因实验研究中,莪术提取物及其有效成分能不同程度的诱导CYP3A4的表达;在大鼠体内实验中,莪术提取物能够增加CYP450蛋白含量和CYP3A酶活性;在mRNA水平上,莪术提取物能够明显诱导CYP3A1及CYP3A2的基因表达。结论莪术提取物及其有效成分能够明显激活PXR并诱导CYP3A4的转录表达;莪术提取物对大鼠体内CYP3A的酶活性及mRNA表达均有明显诱导作用。     

辣木叶及辣木籽对大鼠CYP450酶3种亚型基因表达影响

目的:研究辣木叶及辣木籽对大鼠肝脏CYP450亚型酶中mRNA及蛋白表达量的影响。方法:将SD大鼠随机分为空白组(0.5%羧甲基纤维素钠混悬溶液)、辣木叶高、中、低剂量组(分别为0.813 8,0.406 9,0.203 5g·kg^-1);辣木籽高、中、低剂量组(分别为1.067 4,0.533 7,0.266 9g·kg^-1)。灌胃给药,给药容量为10mL·kg^-1,2次/天,连续给药14d,取大鼠肝脏,采用实时荧光定量PCR(RT-qPCR)及蛋白免疫印迹(Western-blot)法检测大鼠肝脏中CYP2E1、CYP3A1及CYP1A2的mRNA及蛋白相对表达量。结果:辣木叶高剂量组对CYP2E1的mRNA表达有明显抑制作用(P<0.05);在(0.813 8±0.203 5)g·kg^-1剂量范围内,辣木叶对CYP1A2mRNA表达的抑制作用随给药剂量增加而增加(P<0.05)。本实验剂量范围内的辣木籽对3个酶的mRNA表达都有明显的抑制作用(P<0.05),其抑制效率CYP2E1>CYP3A1>CYP1A2。高剂量组辣木叶及辣木籽对CYP2E1蛋白表达都有明显抑制作用(P<0.01);中、低剂量组的辣木籽对CYP3A1及CYP1A2蛋白表达都有不同程度的抑制作用(P<0.05;P<0.05);中剂量辣木叶对CYP1A2蛋白表达抑制作用显著(P<0.01)。结论:辣木叶及辣木籽对大鼠肝脏中3个亚型酶的mRNA及蛋白表达都有不同程度的抑制作用。     

Age-related changes in the protein and mRNA levels of CYP2E1 and CYP3A isoforms as well as in their hepatic activities in Wistar rats. What role for oxidative stress?

Drug biotransformation and its therapeutic effect may be modified during ageing. Among different causative factors of ageing, the impairment of normal cellular functions by free radicals has been evoked as playing a critical role. The effect of age on the expression and activity of CYP2E1 and CYP3A was investigated in male Wistar rats of 3, 8, 11 and 18 months old. The total cytochrome P450 as well as the expression and the activity (midazolam oxidation) of CYP3A isoforms did not change until 18 months of age. Chlorzoxazone hydroxylation (CYP2E1 activity) increased from 3 to 8 months, remained constant between 8 and 11 months and then progressively decreased until 18 months. Interestingly, CYP2E1 microsomal protein followed the same enzyme activity profile from 3 to 8 months, but remained constant thereafter. The level of CYP2E1 mRNA did not change over the whole period. While the amount of proteins did not change after 8 months, their functionality may be affected by oxidative stress (increase in thiobarbituric acid reactive substances, decrease in reduced glutathione level). However, no changes in carbonyl protein content were observed. The decrease in CYP2E1 activity in rats after 11 months is most probably due to post-translational modifications of CYP2E1 proteins. Indeed, it may be correlated with an accumulation of oxidative damage. Since no change was observed in CYP3A activity or in their protein and mRNA content, it seems that such isoforms should be less affected by oxidative stress.     

Estradiol enhances and estriol inhibits the expression of CYP1A1 induced by 2,3,7,8-tetrachlorodibenzo-p-dioxin in a mouse ovarian cancer cell line

2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) is a ubiquitous pollutant and promoter of carcinogenesis. This study investigated the interaction between TCDD and different estrogens in a cancer cell line (ID8) derived from mouse ovarian epithelium. TCDD-induced ethoxyresorufin-O-deethylase (EROD) activity and cytochrome P4501A1 (CYP1A1) expression in a dose- and time-dependent manner. Estrogen receptor (ER) alpha mRNAs were constitutively expressed, but ER beta and progesterone receptor (PR) mRNAs were not expressed. Induction of EROD by TCDD was completely inhibited by a alpha-naphthoflavone and phenanthroline, two aryl hydrocarbon receptor (AhR) antagonists. Progesterone and gonadotropins (FSH and LH) had no effect on the induction of EROD by TCDD. Congeners of 17beta-estradiol (E2) increased the induction of EROD activity by TCDD dose-dependently in the relative potency order: estrone (El)>E2> or = 4-hydroxyestradiol (4OHE2)> or = 2-hydroxyestradiol (2OHE2). In contrast, estriol (E3) decreased EROD activity induced by TCDD. E2 increased TCDD-induced CYP1A1 protein and mRNA whereas E3 decreased both the protein and mRNA. E2 did not alter luciferase activity induced by TCDD in cells transfected with a luciferase reporter containing dioxin response elements (DRE) or a CYP1A1 promoter. In contrast, E3 dose-dependently decreased the luciferase activity. A pure anti-estrogen (ICI 182780) inhibited the interaction between E2 and TCDD but did not block E3's effect on EROD activity. These results indicate that E2 may affect TCDD-induced CYP1A1 expression by a mechanism different from E3 in ID8 cells. It appears that the potentiation of E2 in the induction of CYP1A1 by TCDD occurs by a mechanism involving ER alpha since a specific ER antagonist blocked the potentiation. The inhibitory effect of E3 may be due to a rapid direct effect on EROD and a later suppression of CYP1A1 expression.     

Ephedra water decoction and cough tablets containing ephedra and liquorice induce CYP1A2 but not CYP2E1 hepatic enzymes in rats

1. Ephedra water decoction (EWD) and cough tablets containing ephedra and liquorice (maxing cough tablets, MXCT) have been widely used in the treatment of asthma. In the clinic, EWD and MXCT may be prescribed with theophylline, one of the most popular antiasthmatic drugs. CYP1A2 and CYP2E1 are mainly involved in the oxidative metabolism of theophylline in human liver. Drug interactions involving the cytochrome P450 (CYP) isoforms generally are of two types: enzyme induction or enzyme inhibition. Enzyme inhibition reduces metabolism, whereas induction can increase it.

2. To evaluate the pretreatment effect of EWD and MXCT on CYP1A2 and CYP2E1, CYP1A2 and CYP2E1 activity, the protein expression and mRNA expression levels were determined. After pretreatment with EWD or MXCT, the enzyme activity, mRNA expression and protein expression of CYP1A2 were increased significantly (p?<?0.05), but enzyme activity of CYP2E1 did not change compared with the control.

3. It was demonstrated that EWD or MXCT pretreatment obviously induced CYP1A2, therefore, in patients taking EWD or MXCT, possible CYP-induced drug interaction should be noted to decrease the risk of therapeutic failure or adverse effects resulting from the use of additional therapeutic agents.     

18α-甘草酸下调“胶原蛋白凝胶三明治”培养的大鼠肝细胞P450酶活性及mRNA表达

研究 18α 甘草酸 (18α GA)对肝细胞主要细胞色素P4 50 (CYP)药物代谢酶的影响 ,并初步探讨其分子机理 .采用“胶原蛋白凝胶三明治”培养的原代大鼠肝细胞 ,加 18α GA孵育 ,酶学测定CYP1A1(7 乙氧基异口恶唑O 脱乙基酶 ,EROD) ,CYP2E1(苯胺羟化酶 ,ANH)和CYP3A(红霉素N 脱甲基酶 ,ERD)活性 ,逆转录聚合酶链反应测定CYP1A1,CYP2E1和CYP3A1mRNA表达水平 .结果可见 ,18α GA浓度依赖性 (50～ 4 0 0mg·L- 1)抑制大鼠肝细胞EROD ,ANH和ERD活性 ,2 0 0mg·L- 1作用最强 ,抑制率分别可达 59.6 % ,6 9.7%和 4 4 .7% ,且呈时间依赖性 ,于d 4达高峰 ;浓度依赖性 (50～ 2 0 0mg·L- 1)抑制CYP1A1,CYP2E1和CYP3A1mRNA表达水平 ,分别可达 4 4 .5% ,58.1%和 37.0 % .上述结果表明 18α GA在转录水平下调大鼠肝细胞CYP1A1,CYP2E1和CYP3A1表达