白芍配伍制川乌对芍药苷组织分布的影响及制川乌“引经”作用探讨

目的：研究白芍配伍制川乌经皮给药对白芍中芍药苷组织分布的影响,探讨制川乌的"引经"作用。方法：SD大鼠随机分为2组,分别经皮给予白芍凝胶及白芍-制川乌凝胶,连续给药5 d,末次给药后4,8,20 h采集大鼠皮肤、脑、心、肺、肝、脾、肾等组织,用甲醇沉淀蛋白,上清液氮气吹干,流动相复溶,应用高效液相色谱（HPLC）法测定组织中芍药苷的含量;采用SPSS、偏最小二乘判别（PLS-DA）分析软件,比较配伍前后芍药苷在各组织中分布的变化情况。结果：与白芍单用组比较,经皮给药4,8 h后,配伍组中芍药苷在皮肤、肝组织中显著增加（P<0.01）;同时给药8 h后,芍药苷在肾、肺组织的分布亦明显提高（P<0.01）;变量重要性因子（VIP）分析表明,芍药苷在肾组织中的VIP值最大。结论：白芍配伍制川乌可以改变芍药苷的组织分布而发挥"增效"作用,而组织分布的改变可能与制川乌的"引经"作用有关。     

mPEG-PLGA聚合物对大鼠肝脏CYP450酶活性的影响

目的：研究mPEG-PLGA聚合物对大鼠肝CYP450酶活性的影响。方法：采用芘荧光探针技术测定mPEG-PLGA聚合物的临界胶束浓度（CMC）,并用薄膜分散法制备mPEG-PLGA聚合物胶束;分别采用大鼠肝微粒体和原代大鼠肝细胞模型,将mPEG-PLGA聚合物溶液与CYP450酶特异性探针底物孵育,经液-质联用技术（LC-MS/MS）检测代谢产物,通过比较代谢产物生成量的变化,评价聚合物对CYP450酶的抑制和诱导作用。结果：mPEG-PLGA聚合物的CMC为5.37 μg·mL^-1;mPEG-PLGA聚合物浓度低于CMC时对大鼠肝CYP450酶无抑制作用;当聚合物胶束质量浓度≥100 μg·mL^-1时显示有抑制作用,且呈现浓度依赖性。mPEG-PLGA聚合物对CYP1A1/B2、CYP1A2、CYP2B1、CYP2C6、CYP2C11、CYP2D2、CYP3A1/2（底物为咪达唑仑）、CYP3A1/2（底物为睾酮）7种酶亚型的IC₅₀值分别为1.13,2.37,2.38,1.77,1.32,1.17,1.12,0.91 mg·mL^-1,其中对CYP3A1/2的抑制作用最为明显。mPEG-PLGA聚合物在0.1~1 000 μg·mL^-1质量浓度范围对CYP1A2酶均有诱导作用,且在高质量浓度1 000 μg·mL^-1时最强（P<0.001）;而该聚合物仅在0.1 μg·mL^-1时对CYP2B1、CYP2C6和CYP3A1/2酶呈现诱导作用（P<0.05）。结论：mPEG-PLGA聚合物对大鼠肝脏CYP450酶亚型活性有一定的抑制和诱导作用,其抑制和诱导作用程度与酶亚型种类和聚合物浓度有关。     

丹红注射液对大鼠肝微粒体5种CYP亚型酶活性的影响

摘要目的研究丹红注射液对5种细胞色素P450亚型酶活性的影响,为临床合理用药提供参考。方法采用大鼠体外肝微粒体孵育法,分别以非那西丁、甲苯磺丁脲、右美沙芬、氯唑沙宗、睾酮为CYP1A2、CYP2C9、CYP2D6、CYP2E1、CYP3A4的探针药物,在大鼠肝微粒体孵育体系中孵育,用高效液相色谱（HPLC）法测定相应的代谢产物,比较空白对照组和丹红注射液低、中、高剂量组之间探针药物代谢率的差异,评价丹红注射液对各亚型酶活性的影响。结果在体外肝微粒体孵育体系中,丹红注射液低剂量组中CYP1A2 和CYP2C9活性与空白对照组相比,差异无统计学意义（P＞0.05）;中和高剂量组中CYP1A2和CYP2C9活性与空白对照组相比降低,差异有统计学意义（P＜0.05或P＜0.01）;丹红注射液低、中、高剂量组中CYP2D6、CYP2E1、CYP3A4的活性与空白对照组相比,差异无统计学意义（P＞0.05）。丹红注射液对大鼠肝微粒体CYP1A2酶活性的半数抑制浓度（IC50）和抑制常数（Ki）分别为0.54%和0.226%。结论丹红注射液对大鼠肝微粒体CYP1A2酶活性有抑制作用,且为混合型抑制;对CYP2C9有弱抑制作用;对CYP2D6、CYP2E1、CYP3A4酶活性无明显影响。     

丹参-红花组分配伍对雌、雄性心肌缺血大鼠肝药酶亚型影响的比较研究

目的 比较丹参-红花组分配伍对不同性别大鼠肝药酶亚型CYP1A2、CYP2E1和CYP3A4的影响。方法 取SD大鼠按不同性别随机分为丹参-红花高、低剂量（生药4、2 g/kg）组及模型组和对照组,ip盐酸异丙肾上腺素制备心肌缺血模型,丹参-红花高、低剂量组给予相应提取物,模型、对照组给予等体积的蒸馏水,连续ig给药21 d后,取肝组织剪碎制备微粒体,加入非那西丁、氯唑沙宗、睾酮分别作为CYP1A2、CYP2E1和CYP3A4的特异性探针底物,体外温孵育,建立高效液相色谱（HPLC）法检测探针底物浓度,测定CYP1A2、CYP2E1和CYP3A4活性。结果 ①雄性大鼠实验结果显示,与对照组比较,模型组显著抑制CYP2E1和CYP3A4的活性（P<0.05、0.01）;与模型组比较,丹参-红花高剂量组显著抑制CYP2E1和CYP3A4的活性（P<0.05、0.01）;低剂量组显著抑制CYP2E1的活性（P<0.05）,诱导CYP3A4（P<0.01）。②雌性大鼠实验结果显示,与对照组比较,模型组显著抑制CYP2E1和CYP3A4的活性（P<0.05）,对CYP1A2的影响不显著;与模型组比较,丹参-红花高剂量组显著抑制CYP1A2、CYP2E1和CYP3A4的活性（P<0.05、0.01）;丹参-红花低剂量组抑制CYP2E1的活性（P<0.05）,对CYP1A2和CYP3A4的影响不显著。③实验结果对比显示,丹参-红花对雄性、雌性大鼠肝药酶亚型的影响相同点是均抑制了CYP2E1和CYP3A4活性,尤其对CYP2E1的抑制作用比较明显;不同点是丹参-红花低剂量诱导了雄性大鼠CYP3A4活性,但对雌性大鼠CYP3A4活性无明显影响。结论 丹参-红花组分配伍对不同性别大鼠部分肝药酶亚型活性的影响存在一定的差异。     

常春藤皂苷元对体外人肝微粒体中5种常见细胞色素P450酶的抑制作用研究

目的 考察常春藤皂苷元对人肝微粒体中的5种细胞色素P450（CYP450）酶的抑制作用。方法 采用Cocktail探针药物法,在肝微粒体中加入常春藤皂苷元与混合探针底物[包含非那西丁（CYP1A2探针底物）、双氯芬酸钠（CYP2C9探针底物）、苯乙妥英（CYP2C19探针底物）、右美沙芬（CYP2D6探针底物）和咪达唑仑（CYP3A4探针底物）]共同孵育60 min。采用超高效液相色谱-质谱联用法（UPLC-MS/MS）,以甲苯磺丁酰胺为内标,定量检测底物的代谢物含量,并计算常春藤皂苷元和特异性抑制药对人肝微粒体中CYP1A2、CYP2D6、CYP2C19、CYP2C9和CYP3A4的半数抑制浓度(IC₅₀)。结果 常春藤皂苷元对人肝微粒体中CYP1A2、CYP2D6与CYP3A4的IC₅₀值均大于50μmol·L^-1,对CYP2C9及CYP2C19的IC₅₀值分别为4.94μmol·L^-1和18.00μmol·L^-1。结论 常春藤皂苷元对肝微粒体中CYP...     

体外培育牛黄及其主要成分对大鼠肝微粒体细胞色素P450酶作用的体外研究

摘要：目的:探讨体外培育牛黄（CBS）及其主要成分对大鼠肝微粒体6种细胞色素CYP450酶同工酶活性的影响。方法:采用大鼠肝微粒体为研究工具,将CBS或其主要成分与CYP1A2、CYP2C19、CYP2C9、CYP2D6、CYP2E1和CYP3A1/2这6种同工酶特异性探针底物共同孵育,通过液相-串联质谱法（LC-MS/MS）检测各探针底物代谢物生成量,评价CBS及其主要成分对大鼠肝微粒体CYP1A2、CYP2C19、CYP2C9、CYP2D6、CYP2E1和CYP3A1/2这6种CYP450酶同工酶的体外抑制作用。结果:CBS对大鼠肝微粒体CYP2D6和CYP2E1两种亚型酶活性无抑制作用,而对CYP1A2、CYP2C19、CYP2C9和CYP3A1/2的活性有一定的抑制作用;其主要成分胆酸（CA）、去氧胆酸（DCA）、熊去氧胆酸（UDCA）等对这6种CYP450酶同工酶具有不同程度的抑制作用。结论:CBS在体外可对CYP1A2、CYP2C19、CYP2C9和CYP3A1/2产生抑制作用,从而可能影响合并用药的体内药动学过程,需进一步开展临床研究。     

灯盏花素注射液对大鼠体外肝微粒体细胞色素P450酶活性的影响

摘 要 目的:研究灯盏花素注射液对大鼠肝微粒体CYP1A2、CYP2C9、CYP2D6、CYP2E1和CYP3A1/2 五个亚型酶活性的影响。方法: 采用大鼠肝微粒体体外孵育法,选用非那西丁（CYP1A2）、甲苯磺丁脲（CYP2C9）、右美沙芬（CYP2D6）、氯唑沙宗（CYP2E1）和睾酮（CYP3A1/2）作为5个亚型酶的探针药物,孵育系统中加入不同浓度的灯盏花素注射液,用HPLC法测定5个亚型酶探针药物代谢产物的生成量,比较空白对照组与不同浓度灯盏花素注射液给药组探针药物的活性,反映灯盏花素注射液对5个亚型酶活性的影响。结果:大鼠肝微粒体体外孵育系统中,灯盏花素注射液对大鼠CYP3A1/2的IC₅₀为29.40μg·ml^-1,K_i为37.78 μg·ml^-1;对CYP1A2、CYP2C9、CYP2D6和CYP2E1的IC₅₀＞200 μg·ml^-1。结论:灯盏花素注射液对大鼠体外肝微粒体CYP3A1/2有弱的抑制作用,对CYP1A2、CYP2C9、CYP2D6和CYP2E1活性无明显影响。     

西洋参总皂苷对大鼠肝微粒体CYP1A2活性的影响

目的考察西洋参总皂苷对大鼠肝微粒体CYP1A2活性的影响。方法将大鼠随机分为空白对照组(空白组)、西洋参总皂苷低剂量组[低剂量组,50 mg/(kg·d)]、西洋参总皂苷中剂量组[中剂量组,100 mg/(kg·d)]、西洋参总皂苷高剂量组[高剂量组,200 mg/(kg·d)]和β-萘黄酮阳性药对照组[阳性药组,80 mg/(kg·d)],预处理11 d后,观察大鼠肝微粒体CYP1A2酶活性、CYP1A2 mRNA表达和CYP1A2酶蛋白表达情况,研究CYP1A2特异性探针底物非那西丁在预处理大鼠体内的药动学变化。结果预处理后,大鼠肝微粒体CYP1A2活性、mRNA和蛋白表达随西洋参总皂苷剂量升高有增加趋势,非那西丁在预处理大鼠体内代谢速率加快。结论西洋参总皂苷对大鼠肝微粒体CYP1A2活性有一定诱导作用。     

紫草羟基萘醌对大鼠肝微粒体CYP2D6的影响

目的研究紫草羟基萘醌（HNA）对大鼠肝微粒体CYP2D6的影响。方法 Wistar大鼠,♂,口服给予不同剂量的HNA（5,60 mg.kg-1.d-1）或等量的空白溶媒,连续给药2周后制备肝微粒体。以体外探针药物右美沙芬的代谢物右啡烷的生成速率来反映CYP2D6的活性,通过比较给药组与空白溶媒组酶活性的差异来评价HNA对大鼠肝微粒体CYP2D6的影响。结果建立了一种以右美沙芬为探针底物评价大鼠肝微粒体CYP2D6活性的方法。口服给予HNA两周后,两个剂量组大鼠的肝微粒体蛋白含量、细胞色素P450总量、b5含量以及CYP2D6的活性与空白溶媒组相比差异均无统计学意义。结论 5 mg.kg-1.d-1和60 mg.kg-1.d-1剂量的紫草羟基萘醌口服2周对Wistar大鼠肝微粒体CYP2D6的活性均无显著影响,没有明显的诱导或抑制作用。     

四物汤效应成分基于CYP酶的相互作用研究

目的研究四物汤效应成分果糖、阿魏酸、芍药苷和川芎嗪及其配伍对CYP同工酶的抑制及诱导作用,为从代谢角度解释中药方剂的配伍规律提供依据。方法应用人肝微粒体体外孵育模型和探针底物代谢产物的LC-MS/MS定量方法,评价各单药及药对配伍组对CYP酶同工酶CYP1A2、2B6、2C9、2C19、2D6和3A4的抑制作用。应用"三明治"培养的大鼠原代肝细胞模型,评价各单药及其药对配伍组对CYP1A和CYP3A的诱导作用。结果果糖、阿魏酸、芍药苷、川芎嗪及其配伍组(100μmol·L-1),对人肝微粒体CYP1A2、2B6、2C9和2C19的抑制率均<62%,对CYP3A4和CYP2D6的活性无影响。各单药及配伍组对CYP3A1/2无明显的诱导作用;芍药苷及其药对和配伍(50μmol·L-1)对CYP1A2诱导活性的提高>阳性诱导剂的40%。结论四物汤各成分及其药对配伍对6个主要CYP同工酶均无明显的抑制作用,芍药苷单药对CYP1A2有一定诱导作用,与果糖、阿魏酸和川芎嗪配伍时,诱导活性明显增强。     

药效学结合正交试验优化复方菝葜中生黄芪、白芍的配伍

目的:通过对复方配伍与提高免疫功能及抗炎活性来探讨复方菝葜中生黄芪、白芍的配伍关系。方法:运用正交设计方法,小鼠腹腔巨噬细胞吞噬鸡红细胞模型,大鼠蛋清足肿胀和肉芽肿模型,以吞噬指标、足肿胀率、肉芽肿重为指标,观察药物配伍对免疫功能,抗炎作用的关系,并对新复方的疗效进行验证试验。结果:正交试验表明,生黄芪、白芍对免疫功能具有增强作用(P<0.05),白芍对炎症有显著增强作用(P<0.05)。在免疫作用方面,新复方有增强小鼠巨噬细胞吞噬鸡红细胞指数,促进ConA诱导的T淋巴细胞增殖作用(P<0.01);可减轻蛋清引起的大鼠足肿胀,与阴性对照组相比(P<0.05);可显著抑制苯酚胶浆导致的大鼠子宫内膜病变,与模型组相比(P<0.05或P<0.01)。结论:优选的复方应配伍生黄芪、白芍。     

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。     

三叶青黄酮诱导肺癌SPC-A-1细胞凋亡与cleaved-caspase-3表达的关系

目的：观察三叶青黄酮诱导肺癌SPC-A-1细胞凋亡作用和对cleaved-caspase-3表达的影响,探讨其抗肺癌的可能作用机制。方法：体外培养SPC-A-1细胞,以不同剂量三叶青黄酮进行处理,未给予三叶青黄酮组作为对照组。采用3-（4,5-二甲基噻唑-2）-2,5-二苯基四氮唑溴盐（MTT）比色分析法,观察三叶青黄酮对SPC-A-1细胞增殖抑制作用,计算半数抑制浓度（IC₅₀）;采用流式细胞仪和TUNEL染色检测三叶青黄酮对SPC-A-1细胞凋亡的影响;分别采用免疫细胞分析和蛋白印记分析（Western blot）检测三叶青黄酮对SPC-A-1细胞cleaved-caspase-3表达的影响。结果：三叶青黄酮对SPC-A-1细胞增殖具有明显抑制作用,呈剂量和时间依赖性,并诱导SPC-A-1细胞凋亡,与对照组比较,差异具有统计学意义（P<0.05或P<0.01）;三叶青黄酮显著增加SPC-A-1细胞cleaved-caspase-3表达水平,与对照组比较,差异具有统计学意义（P<0.05或P<0.01）。结论：三叶青黄酮可显著抑制SPC-A-1细胞增殖,并诱导其凋亡,机制可能与增强cleaved-caspase-3表达有关。     

Roles of cytochrome P450 3A enzymes in the 2-hydroxylation of 1,4-cineole,a monoterpene cyclic ether,by rat and human liver microsomes

1. Oxidation of 1,4-cineole, a monoterpene cyclic ether, was studied in rat and human liver microsomes and recombinant cytochrome P450 (P450 or CYP) enzymes expressed in insect cells in which human P450 and NADPH-P450 reductase cDNAs have been introduced. On analysis with gas chromatography/mass spectrometry, 2- exo -hydroxy-1,4-cineole was identified as a principal oxidation product of 1,4-cineole catalysed by rat and human P450 enzymes. 2. CYP3A4 was a major enzyme involved in the 2-hydroxylation of 1,4-cineole by human liver microsomes, based on the following lines of evidence. First, 1,4-cineole 2-hydroxylation activities catalysed by human liver microsomes were inhibited by ketoconazole, a potent inhibitor of CYP3A activities, and an anti-CYP3A4 antibody. Second, there was a good correlation between CYP3A4 contents and 1,4-cineole 2-hydroxylation activities in liver microsomes of eighteen human samples examined. Finally, of 10 recombinant human P450 enzymes examined, CYP3A4 had the highest activity for 1,4-cineole 2-hydroxylation. 3. Liver microsomal 1,4-cineole 2-hydroxylation activities were induced in rat by pregnenolone 16 α-carbonitrile and dexamethasone and extensively inhibited by ketoconazole, indicative of the possible roles of CYP3A enzymes in this reaction. 4. Kinetic analysis showed that V max / K m for 1,4-cineole 2-hydroxylation catalysed by liver microsomes was higher in a human sample HL-104 (4.6 μM -1?min -1) than those of rat treated with pregnenolone 16 α-carbonitrile (0.49 μM -1?min -1) and dexamethasone (0.36 μM -1?min -1). 5. 1,8-Cineole, a structurally related monoterpene previously shown to be catalysed by CYP3A enzymes, inhibited 1,4-cineole 2-hydroxylation catalysed by human liver microsomes, whereas 1,4-cineole did not inhibit 1,8-cineole 2-hydroxylation activities. Both compounds caused inhibition of testosterone 6 β -hydroxylation by human liver microsomes, the former compound being more inhibitory than the latter. 6. These results suggest that 1,4-cineole and 1,8-cineole, two plant essential oils present in Citrus medica L. var. acida and Eucalyptus polybractea, respectively, are converted to 2-hydroxylated products by CYP3A enzymes in rat and human liver microsomes. It is unknown at present whether the 2-hydroxylation products of these compounds are more active biologically than the parent compound.     

Different in vitro metabolism of paclitaxel and docetaxel in humans, rats, pigs, and minipigs.

We investigated cytochrome P450 (P450)-catalyzed metabolism of the important cancer drugs paclitaxel and docetaxel in rat, pig, minipig, and human liver microsomes and cDNA-expressed P450 enzymes. In rat microsomes, paclitaxel was metabolized mainly to C3'-hydroxypaclitaxel (C3'-OHP) and to a lesser extent to C2-hydroxypaclitaxel (C2-OHP), di-hydroxypaclitaxel (di-OHP), and another unknown monohydroxylated paclitaxel. In pig and minipig microsomes, this unknown hydroxypaclitaxel was the main metabolite, whereas C3'-OHP was a minor product. In minipigs, C2-OHP was the next minor product. In human liver microsomes, 6 alpha-hydroxypaclitaxel (6 alpha-OHP) was the main metabolite, followed by C3'-OHP and C2-OHP. Among different cDNA-expressed human P450 enzymes (CYP1A2, 1B1, 2A6, 2C9, 2E1, and 3A4), only CYP3A4 enzyme formed C3'-OHP and C2-OHP. Docetaxel was metabolized in pig, minipig, rat, and human liver microsomes mainly to hydroxydocetaxel (OHDTX), whereas CYP3A-induced rat microsomes produced primarily diastereomeric hydroxyoxazolidinones. Human liver microsomes from 10 different individuals formed OHDTX at different rates correlated with CYP3A4 content. Troleandomycin as a selective inhibitor of CYP3A inhibited the formation of C3'-OHP, C2-OHP, and di-OHP, as well as the unknown OHP produced in rat, minipig, and pig microsomes. In human liver microsomes, troleandomycin inhibited C3'-OHP and C2-OHP formation, and a suitable inhibitor of human CYP2C8, fisetin, strongly inhibited the formation of 6 alpha-OHP, known to be catalyzed by human CYP2C8. In conclusion, the metabolism of docetaxel is the same in all four species, but metabolism of paclitaxel is different, and 6 alpha-OHP remains a uniquely human metabolite. Pigs and minipigs compared with each other formed the same metabolites of paclitaxel.     

Oxidation of 1,8-cineole, the monoterpene cyclic ether originated from eucalyptus polybractea, by cytochrome P450 3A enzymes in rat and human liver microsomes.

1,8-Cineole, the monoterpene cyclic ether known as eucalyptol, is one of the components in essential oils from Eucalyptus polybractea. We investigated the metabolism of 1,8-cineole by liver microsomes of rats and humans and by recombinant cytochrome P450 (P450 or CYP) enzymes in insect cells in which human P450 and NADPH-P450 reductase cDNAs had been introduced. 1,8-Cineole was found to be oxidized at high rates to 2-exo-hydroxy-1,8-cineole by rat and human liver microsomal P450 enzymes. In rats, pregenolone-16alpha-carbonitrile (PCN) and phenobarbital induced the 1,8-cineole 2-hydroxylation activities by liver microsomes. Several lines of evidence suggested that CYP3A4 is a major enzyme involved in the oxidation of 1,8-cineole by human liver microsomes: (1), 1,8-cineole 2-hydroxylation activities by liver microsomes were inhibited very significantly by ketoconazole, a CYP3A inhibitor, and anti-CYP3A4 immunoglobulin G; (2), there was a good correlation between CYP3A4 contents and 1,8-cineole 2-hydroxylation activities in liver microsomes of eighteen human samples; and (3), of various recombinant human P450 enzymes examined, CYP3A4 had the highest activities for 1,8-cineole 2-hydroxylation; the rate catalyzed by CYP3A5 was about one-fourth of that catalyzed by CYP3A4. Kinetic analysis showed that K(m) and V(max) values for the oxidation of 1,8-cineole by liver microsomes of human sample HL-104 and rats treated with PCN were 50 microM and 91 nmol/min/nmol P450 and 20 microM and 12 nmol/min/nmol P450, respectively. The rates observed using human liver microsomes and recombinant CYP3A4 were very high among other CYP3A4 substrates reported so far. These results suggest that 1,8-cineole, a monoterpenoid present in nature, is one of the effective substrates for CYP3A enzymes in rat and human liver microsomes.     

Cocktail 探针药物法评价辣椒素对大鼠CYP450亚型的影响

目的：采用cocktail 探针药物法研究辣椒素在体外对大鼠肝微粒体CYP 450四种亚型的影响。方法：分为试验组和对照组,试验组采用大鼠肝微粒体孵育体系、探针药物和系列浓度的辣椒素（对照组仅加入缓冲液）共同孵育20 min,反应终止后用HPLC方法检测代谢产物的生成量以代表酶的活性。采用Graphpad prism 5.0计算辣椒素对各亚型的IC50值。将辣椒素与大鼠肝微粒体分别预孵育0,5,10,15,20,30 min,计算不同预孵育时间下各亚型的相对活性百分比。结果：辣椒素对大鼠肝微粒体CYP1A2、CYP2C11、CYP2E1和CYP3A2的IC50值分别为36.21,17.19,51.64,18.86μmol·L-1。预孵育没有增强辣椒素对CYP450的抑制作用。结论：辣椒素在体外对大鼠肝微粒CYP1A2、CYP2C11、CYP2E1和CYP3A2具有抑制作用,且未呈现出预孵育时间依赖性。