丹参-红花药对配伍前后对大鼠肝药酶亚型CYP1A2、CYP2E1和CYP3A4活性的影响

目的 研究丹参、红花药对配伍前后对大鼠肝药酶亚型CYP1A2、CYP2E1和CYP3A4活性的影响。方法 分别选用咖啡因、氯唑沙宗和咪达唑仑作为CYP1A2、CYP2E1和CYP3A4的探针药物。将大鼠随机分为4组,即空白对照组、丹参（1.2 g生药/kg）组、红花（0.4 g生药/kg）组、丹参（1.2 g生药/kg）+红花（0.4 g生药/kg）组,按上述剂量ig给药7 d。于末次给药后30 min,尾iv探针药物咖啡因、氯唑沙宗和咪达唑仑溶液,在不同的时间点取血进行检测;以甲硝唑为内标,采用HPLC法检测探针药物咖啡因、氯唑沙宗和咪达唑仑的量,评价各药物组对大鼠CYP3A4、CYP2E1和CYP1A2活性的影响。结果 与空白对照组比较,丹参组咖啡因、氯唑沙宗和咪达唑仑的清除率（CL）有所增强,曲线下面积（AUC）减少,其半衰期（t_1/2）有减少趋势,但差异均不显著;红花组咖啡因和氯唑沙宗的CL有所降低,但差异不显著,咪达唑仑的CL显著降低（P<0.01）,氯唑沙宗的AUC增加,但差异不显著,咖啡因和咪达唑仑的AUC明显增加（P<0.05、0.01）;丹参+红花组咖啡因和氯唑沙宗的CL明显降低（P<0.05）,曲线下面积（AUC）明显增加（P<0.05）,其t_1/2有延长趋势,但差异不显著。结论 丹参、红花配伍后对CYP450亚型CYP1A2和CYP2E1有抑制作用,这可能是丹参、红花配伍协同增效的作用机制之一。     

酒精性肝损伤大鼠细胞色素P450 CYP2E1和细胞色素P450 CYP3A的代谢活性

目的观察酒精性肝损伤对大鼠细胞色素P450CYP3A(CYP3A)和细胞色素P450CYP2E1(CYP2E1)代谢活性的影响。方法采用ig给予白酒制备大鼠酒精性肝损伤模型,检测血清中谷丙转氨酶(GPT)和谷草转氨酶(GOT)活性,采用HE染色法光镜下观测酒精对肝脏损伤程度。大鼠ip给予CYP3A探针药物咪达唑仑10mg·kg-1或ig给予CYP2E1探针药物氯唑沙宗50mg·kg-1后,采用高效液相色谱法测定不同时间点大鼠血浆中咪达唑仑和氯唑沙宗的血药浓度,并应用3P87软件计算其药代动力学参数,以考察CYP2E1和CYP3A的代谢活性的变化。大鼠ig给予氯唑沙宗80mg·kg-1后,热板方法测定大鼠添足次数和添足反射潜伏期。结果酒精性肝损伤可致大鼠肝小叶结构不清,肝索排列紊乱,肝细胞体积增大,呈弥漫性中度水变性,肝窦受压,大部分肝细胞胞浆内见大小不等的脂肪空泡;与正常对照组相比,酒精性肝损伤组大鼠GPT和GOT活性分别增加了16.0%和20.0%(P<0.05,P<0.01)。酒精性肝损伤致大鼠CYP2E1对探针药物氯唑沙宗的代谢活性增强,AUC,t1/2和cmax分别降低了38.0%,30.5%和35.0%(P<0.05);酒精肝损伤组大鼠氯唑沙宗镇痛效果明显降低;酒精性肝损伤致大鼠CYP3A对探针药物咪达唑仑的代谢活性增强,AUC,t1/2和cmax分别降低了122.6%,54.9%和56.9%(P<0.01,P<0.05)。结论酒精性肝损伤可使大鼠CYP2E1和CYP3A代谢活性增强。     

毛冬青胶囊对大鼠体内细胞色素P450 代谢活性的影响*

目的：采用Cocktail探针药物法研究毛冬青胶囊对大鼠CYP1A2、CYP3A2、CYP2C6、CYP2D1、CYP2D2和CYP2E1体内代谢活性的影响。方法：分别以茶碱、咪达唑仑、甲苯磺丁脲、奥美拉唑、右美沙芬和氯唑沙宗作为探针底物,将大鼠随机分为3组：空白对照组、毛冬青的低剂量组和高剂量组。低、高剂量组每日分别灌胃给予毛冬青胶囊1.8、3.6 g·kg-1,空白对照组每日给予与低剂量组等体积的生理盐水,各组均为1次/天,连续14 d。各组分别于第15天给予Cocktail探针药物,于给药前、后不同时间点取血,用LC-MS/MS检测各探针药物的血药浓度,计算药代动力学参数。结果：茶碱低剂量组cmax、AUC0-t有极显著差异（P≤0.01）;甲苯磺丁脲高剂量组和氯唑沙宗低剂量组AUC0-t有显著差异（P≤0.05）;其他无统计学差异。结论：毛冬青胶囊对大鼠体内CYP2C6和CYP1A2有强诱导作用,对CYP2E1有中强诱导作用,其他亚型基本无影响。     

雷公藤活性成分对大鼠体内P450酶活性的影响

目的用Cocktail探针药物法,研究雷公藤片对大鼠肝CYP450的影响。方法分别以奥美拉唑和咪达唑仑作为CYP2C19和CYP3A4的探针药,将大鼠随机分为低剂量和高剂量两组,每日早晚灌胃雷公藤片,采用液质联用法测定连续使用雷公藤片前后大鼠血浆中相应的探针药物的浓度及其药代动力学参数。结果连续灌胃10 d后,与用药前比较,奥美拉唑、咪达唑仑的血药浓度及其药代动力学参数有明显改变;低剂量组和高剂量组中咪达唑仑的AUC明显增加,CL/F明显降低,T12增大,Vd/F和Tmax变化不明显,高剂量组中Cmax有所增大;低剂量组中奥美拉唑的T21和Vd/F有所增大,高剂量组中AUC增加(P<0.05)。结论连续灌胃雷公藤片10 d后,雷公藤片对大鼠体内CYP3A4酶具有抑制作用;对CYP2C19酶具有一定的抑制作用。     

复方银杏叶胶囊对肝损伤大鼠CYP2E1、CYP3A4的影响

目的研究复方银杏叶胶囊(CGB)对酒精性肝损伤大鼠CYP2E1、CYP3A4活性的影响。方法正常组和酒精性肝损伤模型组均以CGB[(250 mg/(kg.d)]灌胃,分别在灌胃CGB前及灌胃1周后,灌胃探针药氯唑沙宗(50 mg/kg)及氨苯砜(20 mg/kg),于探针药灌后24 h内不同时间点采血,测定各探针药血药浓度。结果灌胃CGB前,模型组氯唑沙宗和氨苯砜的AUC0-24、Cmax均显著低于正常组(P<0.05或P<0.01)。灌胃CGB后,模型组氯唑沙宗和氨苯砜的AUC0-24、Cmax均较灌胃前显著升高(P<0.05或P<0.01);且氯唑沙宗的t1/2灌胃CGB后明显高于灌胃前(P<0.05)。结论 CGB能够明显抑制酒精性肝损伤大鼠CYP2E1、CYP3A4酶活性。     

雷公藤多苷片对大鼠药物代谢酶CYP2E1和CYP3A4活性的影响

目的:研究雷公藤多苷片对大鼠CYP450亚型酶CYP2E1和CYP3A4活性的影响方法:16只Wistar大鼠随机分成2组,每组8只,实验组给予雷公藤多苷片(1 mg·kg^-1·d^-1,ig,qd),对照组给予同体积的纤维素钠空白溶剂,连续给药10d后同时静脉给予探针药物氯唑沙宗(5 mg·kg^-1)和咪达唑仑(2 mg·kg^-1)。HPLC法测定两个探针药物的血药浓度,计算其药物动力学参数,评价CYP450亚型酶CYP2E1和CYP3A4的活性。结果:与对照组比较,实验组的氯唑沙宗主要药物动力学参数无明显变化（P>0.05）,而咪达唑仑的CL和AUC较对照组差异有统计学意义（P<0.05）。结论:雷公藤多苷片对大鼠的CYP2E1酶活性无明显影响,对CYP3A4酶活性有一定的抑制作用。     

Cocktail探针药物法评价威麦宁胶囊对大鼠体内CYP450活性的影响

目的采用Cocktail探针药物法评价威麦宁胶囊对大鼠体内6种CYP450亚型酶活性的影响。方法分别选用甲苯磺丁脲、氯唑沙宗、茶碱、咪达唑仑、奥美拉唑和右美沙芬作为CYP2C6、CYP2E1、CYP1A2、CYP3A2、CYP2D1和CYP2D2的探针底物。大鼠每日灌胃威麦宁胶囊1.6 g·kg-1,采用LC-MS/MS测定给药前后大鼠体内6种混合探针的血药浓度,计算药动学参数。结果威麦宁胶囊连续给药2周后,与给药前相比,奥美拉唑ρmax、AUC0-t、tmax及AUC0-∞显著升高(P<0.05);咪达唑仑ρmax、AUC0-t和AUC0-∞显著升高(P<0.01或P<0.05);右美沙芬ρmax、AUC0-t升高(P<0.05);甲苯磺丁脲t1/2、AUC0-∞和tmax显著升高(P<0.01或P<0.05),而CL/F显著降低(P<0.01),ρmax、AUC0-t无显著改变(P>0.05);氯唑沙宗ρmax升高(P<0.05),CL/F降低(P<0.05),AUC0-t升高但无显著差异(P>0.05);茶碱ρmax、AUC0-t升高但无显著差异(P>0.05)。表明奥美拉唑、咪达唑仑和右美沙芬代谢明显减慢(均P<0.05),茶碱、甲苯磺丁脲、氯唑沙宗的代谢无显著差异;威麦宁胶囊对大鼠体内CYP2D1、CYP3A2、CYP2D2酶有抑制作用,对CYP1A2、CYP2C6、CYP2E1酶的活性无显著影响。结论当威麦宁胶囊与CYP2C19、CYP3A4、CYP2D6酶的底物药物合用时,需要调整给药剂量,避免因药物相互作用使体内血药浓度过高产生毒副作用。     

速效救心丸对大鼠体内CYP450酶活性影响的研究

目的采用Cocktail探针药物法研究速效救心丸对大鼠体内药物代谢酶CYP2E1和CYP3A4的影响,为临床用药提供参考。方法 Wistar大鼠,随机分为,①实验组:灌胃给予速效救心丸(给药体积0.5mL/100g,给药剂量64.8mg·kg-1);②对照组:灌胃给予等体积的纤维素钠混悬液。采用高效液相色谱法(HPLC)测定探针底物氯唑沙宗和咪达唑仑的血药浓度,计算其药代动力学参数,考察大鼠体内CYP2E1及CYP3A4酶的活性。结果实验组氯唑沙宗的代谢无显著性差异,咪达唑仑的代谢明显减慢。结论速效救心丸对大鼠的CYP2E1酶活性无明显影响,对CYP3A4酶活性有抑制作用。     

免疫性肝损伤和酒精性肝损伤中CYP2E1代谢活力的差异性变化

目的:观察免疫性肝损伤和酒精性肝损伤对大鼠CYP2E1代谢活力的影响。方法:采用尾静脉注射卡介苗诱发大鼠产生免疫性肝损伤,采用白酒灌胃法制备大鼠酒精性肝损伤模型,HPLC法测定经CYP2E1代谢的探针药物氯唑沙宗血药浓度经时变化。结果:卡介苗刺激可致大鼠肝脏明显肿大,大量单核、淋巴细胞浸润,肉芽肿形成;致大鼠CYP2E1对探针药物氯唑沙宗的代谢活性减弱,AUC增大,Cmax增大。酒精性肝损伤可致肝小叶结构不清,肝索排列紊乱,肝细胞体积增大,呈弥漫性中度水变性,肝窦受压,大部分肝细胞胞浆内见大小不等的脂肪空泡。致大鼠CYP2E1对探针药物氯唑沙宗的代谢活性增强,AUC减少,Cmax减少。结论:免疫性肝损伤可致CYP2E1代谢活性降低,酒精性肝损伤可致CYP2E1代谢活性增强。     

糖尿病模型大鼠肝脏CYP2E1酶活性的变化

采用四氧嘧啶诱发糖尿病大鼠模型,测定肝苯胺羟化酶及其他药酶活性,同时用氯唑沙宗探针间接评价CYP2E1的活性。结果表明,糖尿病大鼠苯胺羟化酶活性增加80%,伴有其他药酶活性增加。大鼠单次po氯唑沙宗50mg·kg^-1,糖尿病组氯唑沙宗的C_max和AUC分别减少37%和34%,6 羟氯唑沙宗的Tpeak缩短,羟化指数(OH-CZX与CZX的AUC比或浓度比)升高表明糖尿病大鼠可诱导CYP2E1活性。提示糖尿病患者服用经CYP2E1酶代谢的药物应慎重。     

振源胶囊对细胞色素P_(450)酶CYP1A2、CYP3A4、CYP2E1的影响

目的:研究振源胶囊对细胞色素P450酶CYP1A2、CYP3A4、CYP2E1的影响。方法:用Cocktail探针药物法,将Wistar大鼠随机分组,灌胃给予振源胶囊溶液,以生理盐水组为空白对照,诱导10d,于股动脉插管,注射给予3种探针药物咖啡因、氨苯砜、氯唑沙宗,通过高效液相色谱法检测各探针药物的代谢率来评价各组CYP1A2、CYP3A4、CYP2E1亚型酶的活性;药动学计算采用DAS2.0软件完成。结果:给予振源胶囊的大鼠,咖啡因代谢加快,半衰期缩短;氨苯砜代谢减慢,半衰期延长;氯唑沙宗半衰期与空白对照组比较无显著差异(P>0.05)。结论:振源胶囊对大鼠CYP1A2有诱导作用,对CYP3A4有抑制作用,对CYP2E1的作用不明显。     

Effects of Guanxinning injection on rat cytochrome P450 isoforms activities in vivo and in vitro

Abstract

1. We aimed to investigate the regulatory effects of Guanxinning injection (GXNI) on activities of cytochrome P1A2 (CYP1A2), CYP2C11, CYP2D1 and CYP3A1/2 by probe drugs in rats in vivo and in vitro.

2. GXNI-treated and blank control groups were administered GXNI and physiological saline by caudal vein for 14 days consecutively, then they were given the probe drugs of caffeine (10?mg/kg), tolbutamide (10?mg/kg), metoprolol (20?mg/kg) and dapsone (10?mg/kg) by intraperitoneal injection. The blood samples were collected at different times for ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) analysis. Changes of the pharmacokinetics parameters between the GXNI-treated and the blank control groups were used to evaluate the effects of GXNI on the four CYP450 isoforms in rats in vivo. After blood collection, the livers of rats were taken and made microsomes for in vitro tests. The relevant metabolites of phenacetin, tolbutamide, dextromethorphan and testosterone were analyzed quantitatively by high-performance liquid chromatography (HPLC) after microsome incubation. The statistical differences between the two groups were observed to detect the effects of GXNI on the four CYP450 isoforms in rats in vitro.

3. The in vivo and in vitro results demonstrated that GXNI could induce CYP1A2 activity in rats, but had no significant effects on CYP2C11, CYP2D1 and CYP3A1/2.     

A convenient five-drug cocktail for the assessment of major drug metabolizing enzymes: a pilot study

AIMS: To assess the feasibility of administering at the same time low doses of five probe drugs, metoprolol (25 mg), chlorzoxazone (250 mg), tolbutamide (250 mg), dapsone (100 mg) and caffeine (100 mg) to determine simultaneously the activities of CYP2D6, CYP2E1, CYP2C9, CYP3A4, CYP1A2, N-acetyltransferase-2 and xanthine oxidase. METHODS: Ten healthy young non-smoking males received the following drugs or combinations of drugs over a 5-week period: week 1) metoprolol; 2) tolbutamide; 3) caffeine, chlorzoxazone and dapsone; 4) caffeine, chlorzoxazone, dapsone and metoprolol; 5) caffeine, chlorzoxazone, dapsone, metoprolol and tolbutamide. The drugs were self-administered at bedtime and urine was collected for the following 8 h. RESULTS: Mean molar phenotypic ratios obtained after administering metoprolol (mean change of -11%) or tolbutamide (mean change of -0.3%) alone, were not significantly different from those obtained when other drugs were co-administered (P > 0.05). The mean within-subject coefficients of variation were 33%, 18%, 22%, 13%, 16%, 13% and 5% for CYP3A4, CYP2D6, CYP2C9, CYP2E1, CYP1A2, N-acetyltransferase 2 and xanthine oxidase metabolic ratios, respectively. No significant interactions (P > 0.5) were observed during the simultaneous administration of various combinations of the five probe drugs. CONCLUSIONS: We propose that this cocktail, composed of five widely available drugs, constitutes a promising means of simultaneously determining the activities of the major CYP enzymes in large populations.     

Tizanidine is mainly metabolized by cytochrome p450 1A2 in vitro

AIMS: To identify the cytochrome p450 (CYP) enzyme(s) that catalyze the metabolism of tizanidine in vitro. METHODS: The effect of CYP isoform inhibitors on the elimination of tizanidine was studied using pooled human liver microsomes. The metabolism of the drug by a range of human recombinant CYP isoforms was then investigated. RESULTS: Incubation of tizanidine (80 nm) with human liver microsomes resulted in time- and NADPH-dependent substrate consumption with a half-life of 50 min, initial reaction velocity of 1.1 pmol x min-1 x mg-1 protein and intrinsic clearance of 17 ml x min-1 x kg-1. The predicted in vivo hepatic clearance (CLh) of tizanidine using the well-stirred and parallel-tube model was close (68% and 82%, respectively) to its estimated in vivo CLh. Fluvoxamine and furafylline strongly inhibited tizanidine metabolism. Inhibitors specific to isoforms other than CYP1A2 had no substantial effect. Recombinant CYP1A2 metabolized tizanidine to a substantial degree (35% in 45 min), but other recombinant CYPs had little metabolic capacity for the drug. CONCLUSIONS: CYP1A2 is primarily responsible for the metabolism of tizanidine. CYP1A2 inhibitors may inhibit its metabolism also in vivo.     

地非三唑对大鼠肝细胞细胞色素P450 CYP1A1/2的诱导作用

目的 试从mRNA表达水平阐明地非三唑对鼠肝微粒体中细胞色素P450 CYP1A1/2的诱导机制。方法 给SD大鼠腹腔注射地非三唑，采用Trizol法提取大鼠肝脏RNA,用RT-PCR测定经地非三唑处理1, 2及4 d的鼠肝中细胞色素P450 CYP1A1, CYP1A2 mRNA的表达水平。结果 地非三唑处理不同时间的鼠肝细胞中细胞色素P450 CYP1A1, CYP1A2 mRNA的表达水平比空白对照组明显增加，空白对照组CYP1A1吸光度比值为0.270±0.040, 诱导1, 2及4 d的吸光度比值分别为0.343±0.055, 0.417±0.045及0.603±0.083；空白对照组的CYP1A2吸光度比值为0.613±0.189, 而诱导1，2及4 d的吸光度比值分别为1.510±0.226, 3.057±0.518及4.120±0.458。随着诱导时间的增加，细胞色素P450 CYP1A1及CYP1A2 mRNA的表达也逐步增加，诱导时间与表达水平之间存在一定的线性关系,相关系数分别为0.9984和0.9563。结论 地非三唑对细胞色素P450 CYP1A1/2 mRNA表达具有诱导作用。     

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。