血塞通注射液对鼠肝CYP3A体外抑制作用研究

目的：研究血塞通注射液对大鼠肝微粒体CYP3A酶活性的体外抑制作用。方法：在大鼠肝微粒体体外孵育体系中加入CYP3A酶的底物睾酮和不同体积的血塞通注射液,用高效液相色谱法测定睾酮的羟化代谢产物6β-羟基睾酮的生成量反映CYP3A酶的活性。酮康唑为阳性对照药。结果：在大鼠肝微粒体体外孵育体系中,血塞通注射液对CYP3A酶的IC50和Ki值分别为血塞通注射液原液的0．87％和0．43％。结论：血塞通注射液在体外对大鼠肝微粒体CYP3A酶活性有抑制作用,符合混合型抑制模型。     

刺五加注射液对大鼠肝微粒体四种CYP450亚型酶活性的影响

目的:研究刺五加注射液在大鼠体外肝微粒体中对CYP2C9、CYP2D6、CYP2E1和CYP3A4活性的影响,为临床合理联合用药提供参考。方法:在大鼠体外肝微粒体中分别加入四种亚型酶的探针药物甲苯磺丁脲(TB)、右美沙芬(DM)、氯唑沙宗(CLZ)、睾酮(TS)和低、中、高剂量的刺五加注射液,温孵后用HPLC法测定各空白对照组和不同剂量刺五加注射液给药组中各探针药物代谢产物的浓度并比较代谢率的差异,以评价刺五加注射液对各亚型酶活性的影响;中剂量组活性显著降低的亚型酶进一步考察抑制作用的强弱(即IC50和Ki值)。结果:与空白对照组比较,刺五加注射液低、中、高剂量给药组对CYP3A4活性的影响均有统计学意义(P<0.01),抑制率分别为10.22%、19.00%、30.29%,其IC50和Ki值分别为3.96%和2.74%(V/V);低、中、高剂量给药组对CYP2D6活性的影响均无统计学差异(P>0.05);低剂量给药组对CYP2C9、CYP2E1活性的影响无统计学差异(P>0.05),中、高剂量给药组对两个亚型的抑制作用有统计学差异(P<0.05),但中剂量给药组抑制率均小于8.50%,高剂量给药组抑制率均小于12.00%。结论:刺五加注射液对大鼠体外肝微粒体CYP3A4有抑制作用,且符合混合型抑制模型;对CYP2C9、CYP2E1抑制作用较弱;对CYP2D6活性无影响。     

大鼠肝微粒体法测定3种中药对CYP3A4 亚型的作用

［摘要］目的建立肝微粒体测定法,观察中药制剂对CYP3A4 亚型的作用。方法取大鼠肝脏,制备肝微粒体,分别优化肝微粒体体外温孵系统的反应时间、蛋白浓度及探针药物咪达唑仑的浓度;高效液相色谱 质谱联用（HPLC MS MS）法测定大鼠肝微粒体中咪达唑仑的浓度,计算咪达唑仑的活性;在肝微粒体体外温孵系统中分别加入不同浓度的血脂康胶囊、通心络胶囊、枣仁安神胶囊内容物及对照药物酮康唑,测定其半数抑制浓度（IC50）及抑制常数（Ki）。结果肝微粒体体外温孵系统的反应条件为0.4 g&;#8226;L 1大鼠肝微粒体,4 μmol&;#8226;L 1咪达唑仑溶液,37 ℃温育5 min。酮康唑、血脂康胶囊、通心络胶囊的IC50分别为（3.4±0.2）,（25.1±0.3）,（56.2±0.3） mg&;#8226;L 1,枣仁安神胶囊的IC50﹥150 mg&;#8226;L 1;酮康唑、血脂康胶囊、通心络胶囊的Ki分别为（1.7±0.1）,（25.0±0.2）,（50.0±0.3） mg&;#8226;L 1。结论建立了中药制剂对CYP3A4亚型作用的大鼠肝微粒体研究模型。血脂康胶囊和通心络胶囊对大鼠CYP3A4亚型有较弱的抑制作用。     

苦碟子注射液对大鼠肝微粒体CYP450酶5个亚型的体外抑制作用

目的研究苦碟子注射液对大鼠肝微粒体CYP450酶的体外抑制作用。方法制备大鼠肝微粒体。将苦碟子注射液分别与混合探针药物非那西丁、甲苯磺丁脲、奥美拉唑、睾酮和氯唑沙宗共同孵育,UPLC-MS/MS法检测各探针药物的代谢物。结果在测定浓度范围内,苦碟子注射液对CYP2E1、CYP2C9和CYP2C19的活性抑制率小于50%;对CYP1A2、CYP3A4的IC_(50)值分别为12.68%、8.11%,远高于临床日用药浓度0.20%~0.80%。结论在正常剂量下,苦碟子注射液对大鼠CYP2E1、CYP2C9、CYP2C19几乎不显示抑制作用,对CYP1A2、CYP3A4几乎没有抑制作用。     

重组肝CYP3A4与CYP3A29细胞微粒体药物代谢动力学比较

目的 比较巴马小型猪CYP3A29和人CYP3 A4稳定表达重组肝癌细胞株微粒体的药物代谢特征,在分子水平为巴马小型猪作为临床前药物代谢实验动物提供科学依据.方法 以CYP3A特异性代谢底物硝苯地平、睾酮及其抑制药酮康唑为探针药物,将探针药物与重组CYP3A4、CYP3A29细胞微粒体在优化的微粒体浓度、药物浓度、孵育时间等条件下进行体外孵育,高效液相色谱法检测其药物代谢(抑制)动力学参数,并将二者进行比较分析.结果 巴马小型猪CYP3A29与CYP3A4在硝苯地平和睾酮代谢差异无统计学意义(P＞0.05).酮康唑的抑制活性为:当代谢底物为硝苯地平时,酮康唑对CYP3A29和CYP3A4的半数抑制浓度分别为0.090,0.132 μmol·L-1(P＜0.05);当代谢底物为睾酮时,酮康唑对CYP3A29和CYP3A4的半数抑制浓度分别为0.056,0.032 μmol·L-1(P＜0.05).结论 重组CYP3A29与CYP3 A4细胞微粒体对硝苯地平和睾酮活性差异不显著;酮康唑对重组CYP3A29与CYP3A4细胞微粒体硝苯地平和睾酮代谢活性有差异.     

健脾和胃方对大鼠肝微粒体CYP3A1酶活性的影响

目的研究健脾和胃方对大鼠肝微粒体细胞色素P450同工酶3A1（CYP3A1）活性的作用。方法 25只大鼠随机分为5组：空白对照组（生理盐水1 mL·kg-1·d-1,14 d）、地塞米松组（100 mg·kg-1·d-1,3 d）和健脾和胃方高、中、低剂量组（7.146,3.573,1.786 mg·kg-1·d-1,14 d）,每组5只,灌胃给予相应的药物。采用高效液相色谱-紫外检测法,以睾酮为探针,测定睾酮经大鼠肝微粒体温孵后转化的代谢产物6β-羟基睾酮（6β-OHT）的生成速率,以评价各组CYP3A1酶活性。结果空白对照组、地塞米松组和健脾和胃方高、中、低剂量组6β-OHT的生成速率分别为（7.29±0.66）、（27.46±2.35）、（3.51±0.48）、（4.90±1.18）、（6.52±1.23）nmol·mg-1·min-1,健脾和胃方高、中、低剂量组6β-OHT的生成速率与地塞米松组均有显著性差异（P〈0.05）。高、中剂量组与空白对照组有显著性差异（P〈0.05）,低剂量组与空白对照组无显著性差异（P〉0.05）。结论本实验结果表明健脾和胃方对大鼠肝药酶CYP3A1酶活性无诱导作用,健脾和胃方的高、中剂量组能使大鼠肝药酶CYP3A1酶活性下降。     

常用中药单体及其制剂对CYP3A活性的体外抑制作用研究

摘 要 目的:研究常用中药单体及其制剂对CYP3A活性的抑制作用。方法: 在体外肝微粒体孵育体系中加入底物睾酮和不同浓度的中药单体或其制剂,以高效液相色谱法检测6β羟基睾酮的生成量,计算CYP3A酶活性。用GraphPad Prism v5.0软件,按照非线性回归计算出药物对CYP3A抑制作用的IC₅₀值。结果:不同中药单体及其制剂对CYP3A抑制作用的IC₅₀值如下：大黄酸IC₅₀值为36.74 μmol·L^-1;大黄素IC₅₀值为23.09 μmol·L^-1、芦荟大黄素IC₅₀值为23.91 μmol·L^-1,蜂胶IC₅₀值为60.3 μg·mL^-1;水飞蓟素胶囊IC₅₀值为24.5μg·mL^-1;丹参酮ⅡA磺酸钠注射液IC₅₀值为0.14%(v/v);五味子酯甲IC₅₀值为0.56 μmol·L^-1。结论: 大黄中的蒽醌、五味子酯甲、蜂胶、水飞蓟胶囊以及丹参酮ⅡA磺酸钠注射液在体外对鼠或人肝CYP3A酶具有抑制作用,临床上使用相关制剂时应密切关注其可能引起的药物相互作用。     

建立用大鼠肝微粒体快速考察药物体外CYP3A1活性抑制的方法

目的研究酮康唑对大鼠肝微粒体细胞色素P450同工酶3A1（CYP3A1）活性的作用,建立一种用大鼠肝微粒体快速考察药物体外CYP3A1活性抑制的方法。方法采集大鼠肝微粒体,随机分为对照组和药物处理组。酮康唑药物处理组分别加入不同浓度的酮康唑,对照组只加入培养液,混匀后放入37℃培养箱中孵育15 min,然后加入CYP 3A1底物睾酮,继续孵育10 min,最后加入内标物氢化可的松。用HPLC法测定睾酮经大鼠肝微粒体温孵后生成6-β羟基睾酮的量,代表CYP3A1的活性。结果各个处理组与对照组的比较差异均有显著性差异（P〈0.05）;提示在一定浓度范围内,大鼠同工酶CYP3A1的相对活性百分比随着酮康唑浓度的增加而逐渐减低,各处理组与对照组比较差异均有显著性意义（P〈0.5）。半数抑制浓度（IC50）值为3.25μg/ml。结论酮康唑对大鼠肝微粒体细胞色素P450同工酶3A1的活性有强抑制作用,建立的通过大鼠肝微粒体快速考察药物体外CYP3A1探针抑制的方法重复性和稳定性均良好,为评价新药对大鼠肝微粒体CYP3A1的活性的体外作用提供可靠的检测手段。     

消癌平注射液等4种抗肿瘤中药注射剂对人肝微粒体中CYP450酶7种亚型的体外抑制作用研究

目的：考察消癌平注射液等4种抗肿瘤中药注射剂对人肝微粒体CYP450酶7种亚型CYP1A2、CYP2B6、CYP2C8、CYP2C9、CYP2C19、CYP2D6和CYP3A4／5的体外抑制作用。方法：消癌平注射液等4种抗肿瘤中药注射剂分别与7种CYP450酶亚型对应的混合探针药物在人肝微粒体中共同孵育,采用液相色谱-串联质谱（LC—MS／MS）法同时测定这7种探针药物的代谢产物：对乙酰氨基酚、羟基安非他酮、去甲阿莫地喹、4-羟基双氯芬酸、4-羟基美芬妥英、右啡烷和1-羟基咪达唑仑的浓度,分别代表CYP1A2、CYP2B6、CYP2C8、CYP2C9、CYP2C19、CYP2D6和CYP3A4／5的活性,其对CYP450酶亚型的抑制程度以IC50值表示。结果：在体外人肝微粒体孵育体系中,消癌平注射液对CYP1A2、CYP2B6、CYP2C8、CYP2C9、CYP2C19和CYP3A4／5的IC50值分别为0．51％、1．34％、1．42％、0．939／6、1．09％和0．75％,艾迪注射液对CYP2C8的IC50值为0．21％;消癌平注射液对CYP2D6的IC10值为2．58％,艾迪注射液对CYP2B6、CYP2C9、CYP2C19和CYP3A4／5的IC50值分别为13．24％、16．31％、4．27％和3．73％,华蟾素注射液对CYP1A2、CYP2B6、CYP2C8和CYP2D6的IC50值分别为3．50％、28．01％、20．32％和32．59％,康艾注射液对CYP1A2、CYP2B6、CYP2C8、CYP2D6和CYP3A4／5的IC50值分别为2．55％、15．32％、1．44％、1．72％和3．99％,均高于各自的日用药量浓度;在测定浓度范围内,艾迪注射液对CYP1A2和CYP2D6,华蟾素注射液对CYP2C9、CYP2C19和CYP3A4／5,康艾注射液对CYP2C9和CYP2C19的活性抑制率均小于50％。结论：在体外,正常剂量下,消癌平注射液对人CYP1A2、CYP2B6、CYP2C8、CYP2C9、CYP2C19和CYP3A4／5,艾迪注射液体对人CYP2C8均有明显抑制作用;消癌平注射液对CYP2D6,艾迪注射液对CYP2B6、CYP2C9、CYP2C19和CYP3A4／5,华蟾素注射液对CYP1A2、CYP2B6、CYP2C8和CYP2D6,康艾注射液对CYP1A2、CYP2B6、CYP2C8、CYP2D6和CYP3A4／5,均无明显抑制作用;艾迪注射液对CYP1A2和CYP2D6,华蟾素注射液对CYP2C9、CYP2C19和CYP3A4／5,康艾注射液对CYP2C9和CYP2C19,均无抑制作用。     

建立用大鼠肝微粒体快速考察药物体外CYP3A1活性抑制的方法

目的 研究酮康唑对大鼠肝微粒体细胞色素P450同工酶3A1( CYP3A1)活性的作用,建立一种用大鼠肝微粒体快速考察药物体外CYP3A1活性抑制的方法.方法 采集大鼠肝微粒体,随机分为对照组和药物处理组.酮康唑药物处理组分别加入不同浓度的酮康唑,对照组只加入培养液,混匀后放入37℃培养箱中孵育15 min,然后加入CYP 3A1底物睾酮,继续孵育10 min,最后加入内标物氢化可的松.用HPLC法测定睾酮经大鼠肝微粒体温孵后生成6-β羟基睾酮的量,代表CYP3A1的活性.结果 各个处理组与对照组的比较差异均有显著性差异(P＜0.05);提示在一定浓度范围内,大鼠同工酶CYP3A1的相对活性百分比随着酮康唑浓度的增加而逐渐减低,各处理组与对照组比较差异均有显著性意义(P＜0.5).半数抑制浓度( IC50)值为3.25 μg/ml.结论 酮康唑对大鼠肝微粒体细胞色素P450同工酶3A1的活性有强抑制作用,建立的通过大鼠肝微粒体快速考察药物体外CYP3A1探针抑制的方法重复性和稳定性均良好,为评价新药对大鼠肝微粒体CYP3A1的活性的体外作用提供可靠的检测手段.     

Inhibition of CYP3A by Antimalarial Piperaquine and Its Metabolites in Human Liver Microsomes With IVIV Extrapolation

The potential of the antimalarial piperaquine and its metabolites to inhibit CYP3A was investigated in pooled human liver microsomes. CYP3A activity was measured by liquid chromatography-tandem mass spectrometry as the rate of 1′-hydroxymidazolam formation. Piperaquine was found to be a reversible, potent inhibitor of CYP3A with the following parameter estimates (%CV): IC₅₀ = 0.76 μM (29), K_i = 0.68 μM (29). In addition, piperaquine acted as a time-dependent inhibitor with IC₅₀ declining to 0.32 μM (28) during 30-min pre-incubation. Time-dependent inhibitor estimates were k_inact = 0.024 min^?1 (30) and K_I = 1.63 μM (17). Metabolite M2 was a highly potent reversible inhibitor with estimated IC₅₀ and K_i values of 0.057 μM (17) and 0.043 μM (3), respectively. M1 and M5 metabolites did not show any inhibitory properties within the limits of assay used. Average (95th percentile) simulated in vivo areas under the curve of midazolam increased 2.2-fold (3.7-fold) on the third which is the last day of piperaquine dosing, whereas for its metabolite M2, areas under the curve of midazolam increased 7.7-fold (13-fold).     

体外探讨五味子乙素对大鼠肝微粒体CYP3A的影响及其作用机制

目的通过体外药物代谢实验探讨五味子乙素对CYP3A活性的影响,并探讨其作用机制。方法以大鼠肝微粒体为载体,选取咪达唑仑为药物"探针",建立高效液相色谱法(HPLC)检测五味子乙素对肝微粒体代谢咪达唑仑的影响,体外给药测定其IC50值以及相关酶动力学参数,并推测其可能的作用机制。结果孵育体系内源性物质不干扰测定,方法快捷、稳定、灵敏度高。结果显示五味子乙素呈剂量依赖性抑制体外肝微粒体咪达唑仑代谢,其IC50为5.50g.L-1,据此计算其Ki为4.32mol·L-1。结论五味子乙素体外抑制大鼠肝微粒体CYP3A活性,其作用机制为可逆性抑制,属于非竞争性抑制类型。     

Comparative analysis of substrate and inhibitor interactions with CYP3A4 and CYP3A5

To evaluate the role that cytochrome (CYP) 3A5 plays in hepatic drug metabolism, the substrate selectivity and inhibitory potential of over 60 compounds towards CYP3A4 and CYP3A5 were assessed using Escherichia coli recombinant cell lines. CYP3A4-mediated metabolism predominated for many of the compounds studied. However, a number of drugs gave similar CL_int estimates using CYP3A5 compared with CYP3A4 including midazolam (CL_int?=?3.4 versus 3.3?µl?min^–1?pmol^–1). Significant CYP3A5-mediated metabolism was also observed for several drugs including mifepristone (CL_int?=?10.3 versus 2.4?µl?min^–1?pmol^–1), and ritonavir (CL_int?=?0.76 versus 0.47?µl?min^–1?pmol^–1). The majority of compounds studied showed a greater inhibitory potential (IC₅₀) towards CYP3A4 compared with CYP3A5 (eightfold lower on average). A greater degree of time-dependent inhibition was also observed with CYP3A4 compared with CYP3A5. The range of compounds investigated in the present study extends significantly previous work and suggests that CYP3A5 may have a significant role in drug metabolism particularly in populations expressing high levels of CYP3A5 and/or on co-medications known to inhibit CYP3A4.     

五味子甲素对大鼠肝微粒体CYP3A活性的影响

目的：通过体外药物代谢实验探讨五味子甲素对CYP3A活性的影响。方法：以大鼠肝微粒体为载体,选取咪达唑仑（MDZ）作为药物“探针”,建立高效液相色谱（HPLC）检测方法,体外给药测定五味子甲素对MDZ的IC50值以及相关酶动力学参数。结果：孵育体系内源性物质不干扰测定,方法快捷、稳定、灵敏度高。在肝微粒中,五味子甲素对MDZ的IC50浓度为6．26μmol／mL,相关酶动力学参数：Km=15．77μmol／L,Ki=5．50μmol／mL。结论：五味子甲素对大鼠肝微粒体CYP3A活性具有抑制作用,其抑制作用为混合型,即：非竞争与反竞争抑制。     

Inhibition of human liver microsomal CYP by nateglinide

Objectives Nateglinide is metabolized by CYP2C9 and CYP3A4, therefore drug–drug interactions through cytochrome P450 (CYP) inhibition may occur. In this study, we examined the inhibitory effects of nateglinide and its major metabolite N‐[trans‐4‐(1‐hydroxy‐1‐methylethyl)‐cyclohexanecarbonyl]‐d ‐phenylalanine (M1) on various CYP isoforms in human liver microsomes. Methods We used typical substrates (7‐ethoxyresorufin for CYP1A1/2, tolbutamide for CYP2C9, S‐mephenytoin for CYP2C19, bufuralol for CYP2D6, chlorzoxazone for CYP2E1 and midazolam for CYP3A4) in the evaluation of the inhibitory effects, and examined the possibility of mechanism‐based inhibition (MBI) by evaluating the influence of pre‐incubation in the inhibition. Key findings The results showed that nateglinide inhibited CYP2C9 and CYP2C19 with an IC50_app (apparent value of the 50% inhibitory concentration) of 125 μmol/l and 946 μmol/l, respectively, while M1 did not inhibit any of the CYP isoforms. The inhibition constant (K_i) value of the inhibitory effect of nateglinide on CYP2C9 and the 1 + I_in,max,u/K_i value were estimated (where I_in,max,u= the maximum unbound concentration of nateglinide). The 1 + I_in,max,u/K_i value was 1.02 (close to 1), suggesting a low risk of drug–drug interactions. The influence of pre‐incubation on the inhibition by nateglinide of CYP3A4, CYP2C9 and CYP2C19 was examined. The results revealed that the inhibition of CYP by nateglinide was not influenced by pre‐incubation, and that the possibility of MBI is very low. Conclusions The possibility of drug–drug interactions involving nateglinide that might be attributable to CYP inhibition is low.     

Effect of widely used combinations of antiretroviral therapy on liver CYP3A4 activity in HIV-infected patients

AIMS: To evaluate the effects of combined antiretroviral drugs (HAART) on liver CYP3A4 activity using the [(14)C-N-methyl]-erythromycin breath test (ERMBT). METHODS: HIV-infected patients (31 women, 30 men) with mean (+/- SD) age of 38 +/- 9 years were enrolled and underwent complete clinical and laboratory evaluation. Patients were divided into five groups and were treated with two nucleoside analogues (NAs) and one of the following: nelfinavir alone (n = 13), any ritonavir-boosted protease inhibitor with (n = 8) or without (n = 13) nevirapine, nevirapine alone (n = 15), or a third NA (n = 12). Three or four ERMBTs were performed 7 days prior to (D-7) and at the beginning of treatment (D0), D14 (only for patients taking nevirapine) and on D28. RESULTS: Mean baseline liver CYP3A4 activity displayed high interindividual variability (47%) but low intraindividual variability (15%). Women had 30% higher ERMBT values than men [2.7 +/- 1.3 vs. 1.9 +/- 0.7; 95% confidence interval (CI) 20.5, 49.5; P = 0.003]. The ERMBT data correlated with body weight, alpha- and beta-globulins and alanin aminotransferases (0.10 < r(s) < 0.20; P < 0.01). Whereas nevirapine had no effect on liver CYP3A4 activity, nelfinavir-based and ritonavir-boosted drug regimens inhibited it by 69% (95% CI 64.7, 72.9; P = 0.005) and by 95% (95% CI 93.3, 96.7; P = 0.001), respectively. CONCLUSION: Evaluation of the effect of HAART on liver CYP3A4 activity may aid in preventing inappropriate treatment regimens in HIV-infected patients.     

PXR受体调控的CYP3A诱导及其在药物代谢中的重要意义

机体每日都要接触大量外源性化合物（xenobiotics），包括环境、饮食、药物中的各种成分，其中亲脂性化合物如果不能被及时代谢为极性化合物，就会在肝脏蓄积并影响机体正常生理功能，产生毒性甚至致癌。细胞色素P450（CYPS）属于血红素蛋白基因超家族，编码一系列代谢酶系统，参与各类不同结构亲脂性化合物的生物转化，增强代谢物水溶性，利于排出体外，     

Flavonoids diosmetin and luteolin inhibit midazolam metabolism by human liver microsomes and recombinant CYP 3A4 and CYP3A5 enzymes

We evaluated the effects of increasing concentrations of the flavonoids salvigenin, diosmetin and luteolin on the in vitro metabolism of midazolam (MDZ), a probe substrate for cytochrome P450 (CYP) 3A enzymes, which is converted into 1'-hydroxy-midazolam (1'-OH-MDZ) and 4-hydroxy-midazolam (4-OH-MDZ) by human liver microsomes. Salvigenin had only a modest effect on MDZ metabolism, whereas diosmetin and luteolin inhibited in a concentration-dependent manner the formation of both 1'-OH-MDZ and 4-OH-MDZ, with apparent K(i) values in the 30-50mumol range. Both diosmetin and luteolin decreased 1'-OH-MDZ formation by human recombinant CYP3A4, but not CYP3A5, whereas they decreased 4-OH-MDZ formation by both recombinant enzymes. To assess whether any relationship exists between the physico-chemical characteristics of flavones and their effects on MDZ metabolism, we tested the effects of three other flavones (flavone, tangeretin, chrysin) on MDZ metabolism by human liver microsomes. Whereas flavones possessing more than two hydroxyl groups (luteolin, diosmetin) inhibited MDZ biotransformation, flavones lacking hydroxyl groups in their A and B rings (flavone, tangeretin) stimulated MDZ metabolism. We also found close relationships between the maximum stimulatory or inhibitory effects of flavones on 1'-OH-MDZ and 4-OH-MDZ formation rates and their log of octanol/water partition coefficients (logP) or their total number of hydroxyl groups. The results of the study may be of clinical relevance since they suggest that luteolin and diosmetin may cause pharmacokinetic interactions with co-administered drugs metabolized via CYP3A.