贝母、乌头合用对大鼠肝脏CYP450的调控作用

目的:研究乌头、贝母合用对主要药物代谢酶和蛋白质水平的影响,阐明中药产生相互作用的机制。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、贝母合用后CYP1A2、CYP2E1的酶活性均有下降;Western Blot检测显示CYP1A2、CYP2E1、CYP3A2的蛋白质表达水平下降;CYP3A1的蛋白质表达水平上升。RT-PCR检测显示CYP1A2、CYP2E1的mRNA水平下降;CYP3A1、CYP3A2的mRNA水平上升。结论:乌头、贝母合用后抑制CYP1A2、CYP2E1的酶活性,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。     

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。     

木犀草素对大鼠CYP450酶活力和mRNA表达的影响

目的 研究木犀草素对大鼠细胞色素P450（CYP450）酶活力和mRNA表达的影响。方法 SD大鼠随机分为实验组和对照组,连续灌胃木犀草素或水14 d后,同时给予探针药非那西丁、安非他酮、氯唑沙宗和咪达唑仑,并用LC-MS测定给药后不同时间点的血药浓度,计算药动学参数并评估CYP1A2、CYP2B1、CYP2E1和CYP3A1酶活力变化。此外,实时荧光定量PCR （RT-PCR）测定CYP450的mRNA表达水平。结果 实验组大鼠非那西丁、安非他酮、咪达唑仑的药动学参数与对照组相比具有显著性差异,推测木犀草素能诱导大鼠CYP1A2、CYP2B1和CYP3A1活力,而氯唑沙宗的药动学参数2组间没有显著性差异。RT-PCR实验发现,木犀草素能显著上调大鼠CYP1A2、CYP2B1和CYP3A1的mRNA水平,对CYP2E1没有影响。结论 木犀草素会上调CYP1A2、CYP2B1和CYP3A1酶活力及mRNA表达水平。     

五味子乙素对CYP450药物代谢酶诱导作用的体外研究

目的 研究五味子乙素对细胞色素P450(CYP450)酶活性和mRNA表达是否有诱导作用.方法 采用底物法测定人肝原代细胞CYP1A2、CYP2B6和CYP3A4酶的活性,荧光定量PCR检测mRNA的表达.结果 五味子乙素对CYP1A2和CYP3A4的酶活性均低于阳性对照的40%,高浓度的五味子乙素对CYP2B6的酶活性均高于阳性对照的40%;五味子乙素对CYP1A2的mRNA表达小于阴性对照的4倍,高浓度的五味子乙素对CYP2B6和CYP3A4的mRNA表达大于阴性对照的4倍.结论 五味子乙素对CYP1A2和CYP3A4的酶活性没有诱导作用,对CYP2B6的酶活性有潜在诱导作用;五味子乙素对CYP1A2的mRNA表达没有诱导作用,对CYP2B6和CYP3A4的mRNA表达有潜在诱导作用.     

酮康唑对大鼠肝脏CYP450酶系的影响*

目的:观察酮康唑对大鼠肝细胞色素P450及其主要亚型的影响。方法:Sprague-Dawley大鼠用140,280,420μmol.kg-1.d-1酮康唑连续灌胃7 d,测定肝脏微粒体中总CYP450含量和CYP1A1,1A2,1B1,2B1/2,2E1和3A亚型活性。结果:不同剂量酮康唑给药后大鼠肝脏脏器系数、CYP1A1和1B1亚型活性明显增高(P<0.05,P<0.01);总CYP450含量和CYP3A活性显著降低(P<0.01);低剂量的酮康唑抑制CYP1A2和CYP2B1/2亚型的活性,高剂量却出现了诱导作用(P<0.05,P<0.01)。各剂量组对CYP2E1均无明显影响。结论:酮康唑对大鼠肝脏CYP450及主要药物代谢亚型CYP1A1,1A2,1B1,2B1/2和3A有影响,临床长期用药或与经肝脏CYP450代谢的药物联合应用时要注意监测血药浓度和肝脏功能,防止药物代谢减缓出现蓄积中毒或药物代谢加快而降低药效。     

Z24对大鼠肝脏CYP450酶系的影响

目的:观察Z24对大鼠肝脏CYP450酶系的影响.方法:雌性Wistar大鼠,灌胃(ig)给予Z24(0,50,100,200 mg·kg-1·d-1),连续5 d,以0.9%氯化钠溶液作对照,末次给药后次日,处死大鼠,测定肝微粒体中CYP450总含量、细胞色素b5(Cyt-b5)含量、NADPH-CYP450还原酶活性以及1A2,181,2E1,3A4亚型活性.结果:与对照组相比,各剂量组CYP450总含量、NADPH-CYP450还原酶活性及CYPlB1、2El亚型活性均明显升高(P＜0.05);100和200 mg·kg-1组Cyt-b5含量升高(P＜0.05);200 mg·kg-1组CYPlA2和3A亚型活性升高(P＜0.05).结论:Z24对CYP450、NADPH-CYP450还原酶及CYPlB1、2El亚型有诱导作用,剂量达100和200 mg·kg-1时分别对cyt-b5和CYPlA2、3A亚型产生诱导作用.     

参麦注射液和注射用血塞通对大鼠肝脏及肠道药物代谢酶CYP450的影响

目的考察参麦注射液和注射用血塞通对大鼠药物代谢酶细胞色素P450(CYP450)的影响。方法连续给予大鼠试验药物后,制备肝及小肠微粒体;用CO还原差示光谱法,测定肝微粒体CYP450含量;用蛋白免疫印迹法,检测肝微粒体中CYP1A2、CYP2C11、CYP2E1、CYP3A和肠微粒体中CYP3A蛋白的表达量。结果参麦注射液和注射用血塞通组与空白对照组大鼠的肝脏总P450含量无显著性差异(P>0.05)。但参麦注射液可显著诱导肝脏CYP2E1表达,但抑制肠微粒体中CYP3A表达;肝CYP1A2、CYP2C11水平均有所上升。血塞通可显著诱导大鼠肝脏CYP1A2、CYP2E1、CYP2C11、CYP3A蛋白表达,肠CYP3A的表达水平显示出下降趋势。结论参麦注射液和注射用血塞通对大鼠肝脏P450酶总量无影响;但对特定亚型蛋白的表达量有影响,由此可能引发的药物相互作用不容忽视。     

CYP450氧化还原酶遗传多态性对CYP酶影响的研究进展

细胞色素P450氧化还原酶(Cytochrome P450 0xidoreductase,POR)是将电子从NADPH转运至所有肝微粒体的细胞色素P450氧化酶(Cytochrome P450 monooxygenases,CYP)中的唯一供体.药物、类固醇激素等物质的代谢和转化需要CYP参与.POR基因具有遗传多态性,遗传变异可以改变CYP活性,引起P450氧化还原酶缺陷(P450 0xidoreductase deficiency,PORD)、临床药物代谢和反应差异.本文将从POR的结构功能、基因突变引起的疾病及其对酶活性影响三个方面进行论述,总结近年来POR遗传多态性对CYP酶影响的最新研究进展.     

心血管药物速效救心丸和通心络胶囊对大鼠细胞色素P450酶的影响

目的:观察速效救心丸和通心络胶囊对大鼠药物代谢酶细胞色素P450(CYP450)的影响。方法:给予大鼠试验药物后制备肝及小肠微粒体,CO还原差示光谱法测定肝微粒体CYP450含量,蛋白免疫印迹法检测肝微粒体中CYP1A2、CYP2C11、CYP2E1、CYP3A和肠微粒体中CYP3A蛋白的表达量。结果:速效救心丸组和通心络胶囊组与空白对照组比较,大鼠肝脏CYP450含量无显著变化(P>0.05);但是West-ern blotting实验对肝脏和肠道中多种CYP450酶表达量测定的结果显示,速效救心丸可诱导肝脏CYP1A2表达,但抑制肝脏CYP2C11和肠道CYP3A表达(P<0.05);通心络胶囊可诱导大鼠肝脏CYP1A2、CYP2E1蛋白表达(P<0.05)。结论:速效救心丸和通心络胶囊对大鼠肝脏CYP450酶总量无影响,但是,在蛋白质水平对特定亚型蛋白的表达量有影响,由此可能引发的药物相互作用不容忽视。     

参麦注射液对大鼠心脏细胞色素P450酶的调节作用

目的研究参麦注射液及各单药注射液对大鼠心脏P450酶mRNA表达和花生四烯酸代谢的影响。方法 SD大鼠连续腹腔注射参麦注射液及各单药注射液14 d后取心脏,采用实时荧光定量PCR(RT-q PCR)方法,检测各处理组药物对大鼠心脏P450亚酶CYP1A1、CYP1B1、CYP2B1、CYP2C11、CYP2E1、CYP2J3、CYP4A1、CYP4A3、CYP4F1、CYP4F4、CYP4F5、CYP4F6、ANP、BNP、EPHX2mRNA表达的影响。结果对各处理组的心脏P450酶mRNA表达水平检测显示:与空白组比较,除CYP2B1、CYP4A3和CYP4F6参麦注射液对其他CYP各亚型mRNA的表达均表现了上调的作用,红参注射液组对CYP2E1、CYP4A3、CYP4F1和EHPX2mRNA表达有上调作用,麦冬注射液对ANP、BNP和EHPX2mRNA的表达上调作用明显,同时能明显下调CYP2B1和CYP2C11的表达。结论虽然参麦注射液对CYP2B1的作用没有统计学意义,但总体呈现出诱导的趋势,而麦冬注射液对CYP2B1呈现明显的抑制作用,提示红参注射液可能对CYP2B1的诱导作用更大。参麦注射液、红参注射液与麦冬注射液均对CYP2E1、CYP4F1和EHPX2有诱导作用,提示参麦注射液对CYP2E1、CYP4F1和EHPX2的诱导作用可能由复方中的红参和麦冬共同贡献。参麦注射液和麦冬注射液对ANP和BNP均具有诱导的作用,提示在对ANP和BNP的作用中麦冬比红参的作用更强。同时参麦注射液对心血管疾病疗效明确,可能与其对CYP2J3、ANP和BNP等调节作用较强相关。     

甘草水煎液对大鼠肝微粒体细胞色素P450酶活性的影响

目的：观察甘草水煎液对大鼠肝细胞色素P450酶活性的影响。方法：SD大鼠随机分为4组,分别为空白对照组（给予生理盐水）、酶诱导剂组（给予苯巴比妥）、酶抑制剂组（给予西咪替丁）及甘草水煎液组（给予甘草水煎液）,各组动物连续灌胃给药14 d,第15天腹腔注射探针药物非那西丁,不同时间点采集血样后,HPLC法测定血浆中非那西丁浓度,并估算其药代动力学参数。结果：生理盐水组、苯巴比妥组、西咪替丁组及甘草水煎液组非那西丁的t1/2分别为（104±10）、（178±15）、（86±9）、（90±9）min。结论：甘草水煎液对大鼠肝药酶P450具有一定的诱导作用。     

中药对细胞色素P450酶活性影响的研究进展

中药在体内对代谢酶可产生诱导或抑制等作用,增加或减少不良反应,甚至发生毒性反应。笔者通过检索近年文献,归纳研究方法、相互作用机制,探讨中药对肝药酶活性的影响,预测可能的药物间相互作用,为中药的临床应用提供理论依据及策略。     

Biotransformation of chlorpyrifos and diazinon by human liver microsomes and recombinant human cytochrome P450s (CYP)

1. The cytochrome P450 (CYP)-mediated biotransformation of the organophosphorothioate insecticides chlorpyrifos and diazinon was investigated. Rates of desulphuration to the active oxon metabolite (chlorpyrifos-oxon and diazinon-oxon) and dearylation to non-toxic hydrolysis products were determined in human liver microsome preparations from five individual donors and in recombinant CYP enzymes.

2. Chlorpyrifos and diazinon underwent desulphuration in human liver microsome with mean K_m = 30 and 45 μM and V_max = 353 and 766 pmol min^?1 mg^?1, respectively. Dearylation of these compounds by human liver microsome proceeded with K_m = 12 and 28 μM and V_max = 653 and 1186?pmol min^?1 mg^?1, respectively. The apparent intrinsic clearance (V_max/K_m) of dearylation was 4.5- and 2.5-fold greater than desulphuration for chlorpyrifos and diazinon, respectively.

3. Recombinant human CYP2B6 possessed the highest desulphuration activity for chlorpyrifos, whereas CYP2C19 had the highest dearylation activity. In contrast, both desulphuration and dearylation of diazinon were catalysed at similar rates, in the rank order CYP2C19 > CYP1A2 > CYP2B6 > CYP3A4.

4. Both organophosphorothioates were more readily detoxified (dearylation) than bioactivated (desulphuration) in all human liver microsome preparations. However, the role of individual CYP enzymes in these two biotransformation pathways varied according to the structure of the organophosphorothioate, which was reflected in different activation/detoxification ratios for chlorpyrifos and diazinon. Variability in activity of individual CYP enzymes may influence interindividual sensitivity to the toxic effects of chlorpyrifos and diazinon.     

盐酸小檗碱对大鼠肝微粒体细胞色素P450酶含量及活性的影响

目的考察盐酸小檗碱对大鼠肝微粒体的蛋白含量、CYP450酶总量和主要CYP450酶亚型(CYP1A2、CYP2D6、CYP3A4和CYP2C19)活性的影响。方法以溶剂为空白对照灌胃给予盐酸小檗碱250 mg/(kg·d),连续7 d,测定其肝微粒体蛋白含量、CYP450蛋白含量以及CYP1A2、CYP2D6、CYP3A4和CYP2C19活性。结果与空白对照组比较,盐酸小檗碱给药组大鼠肝微粒体蛋白含量及肝微粒体CYP450含量无明显差异(P>0.05)。盐酸小檗碱给药后,给药组大鼠的平均CYP3A4活性是空白对照组的1/2;而两组之间CYP1A2、CYP2D6和CYP2C19的活性相当。结论盐酸小檗碱对大鼠CYP3A4活性有一定抑制作用,对CYP1A2、CYP2D6和CYP2C19的活性没有影响。     

Suppression of male-specific cytochrome P450 isoforms by bisphenol A in rat liver

We examined the effect of bisphenol A (BPA) on microsomal cytochrome P450 (P450) enzymes in rats. Rats were treated intraperitoneally with BPA daily for 4 days, at doses of 10, 20, and 40 mg/kg. Among the P450-dependent monooxygenase activities, testosterone 2α-hydroxylase (T2AH) and testosterone 6β-hydroxylase (T6BH) activities, which are associated with CYP2C11 and CYP3A2 respectively, were remarkably decreased by 40 mg/kg BPA. The levels of the control activities were 13 and 50%, respectively. Furthermore, immunoblotting showed that BPA (20 or 40 mg/kg) significantly reduced CYP2C11/6 and CYP3A2/1 protein levels in rat liver microsomes. In addition, estradiol 2-hydroxylase (ED2H) and benzphetamine N-demethylase (BZND) activities were significantly decreased by BPA at 20 and 40 mg/kg (by 19–73%). The K _m values for T2AH and T6BH in 20 and 40 mg/kg BPA-treated rats were significantly high compared with that in control rats. The V _max for T2AH was dose-dependently decreased by BPA treatment, whereas that of T6BH was only decreased by BPA at 40 mg/kg. On the other hand, lauric acid ω-hydroxylase (LAOH) activity was significantly increased by BPA at 20 and 40 mg/kg (1.5- and 1.7-fold, respectively). Immunoblot analysis showed that 20 and 40 mg/kg BPA induced CYP4A1/2 protein expression. However, the activities 7-ethoxyresorufin O-deethylase (EROD), 7-methoxyresorufin O-demethylase (MROD), 7-ethoxycoumarin O-deethylase (ECOD), 7-benzyloxyresorufin O-debenzylase (BROD), aminopyrine N-demethylase (APND), chlorzoxazone 6-hydroxylase (CZ6H), erythromycin N-demethylase (EMND), and testosterone 7α-hydroxylase (T7AH) were not affected by BPA at any dose. These results suggest that BPA affects male-specific P450 isoforms in rat liver, and that these changes closely relate to the toxicity of BPA. Received: 26 January 1998 / Accepted: 26 February 1998     

卤酚化合物LM49对大鼠肝微粒体细胞色素P450的影响

目的研究LM49对大鼠肝微粒体蛋白及细胞色素P450含量的影响。方法将大鼠分成空白对照组、溶剂对照组、阳性对照组(苯巴比妥组、地塞米松组、β-萘黄酮组)、LM49低、中、高剂量组。给药后采用超速离心法制备大鼠肝微粒体;BCA法测定大鼠肝微粒体蛋白浓度;Omura and Sato法测定大鼠肝微粒体细胞色素P450的含量。结果 给予不同剂量的LM49后,大鼠肝微粒体的蛋白及细胞色素P450含量均明显降低。低、中、高剂量组与对照组比较差异有统计学意义(P<0.05)。结论 LM49对大鼠肝微粒体细胞色素P450具有一定的抑制作用,可能引起肝药酶对某些药物代谢的改变。