炎症过程中细胞色素P450酶活性降低及其机制的研究进展

机体在感染或炎症状态下,肝脏细胞色素P450药物代谢酶mRNA表达和蛋白含量显著降低,酶的催化活性降低。这种变化对人体内药物代谢过程乃至相关药物临床治疗安全性具有显著影响。细胞色素P450异构酶活性降低具有不同的变化过程与模式,反映细胞色素P450酶系具有多种活性调节机制。现有研究表明,细胞色素P450酶活性降低主要发生在基因表达环节,由多种炎症细胞因子介导。阐明炎症对细胞色素P450活性的影响有助于明确细胞色素P450酶活性的调控机制,对指导临床安全合理用药具有重要意义。     

内质网脂质稳态在细胞色素P450酶调控中的作用

脂质是机体内重要的营养物质之一,参与机体的能量供应、生物膜形成以及代谢调节等,内质网是其合成的主要场所。近年来越来越多研究表明,细胞色素P450酶的表达和活性影响机体对有害物质的敏感性以及药物的疗效,影响疾病的发生及发展,而细胞色素P450酶作为膜蛋白受到膜组成的影响。就细胞色素P450酶调控过程中内质网脂质稳态的作用进行综述。     

细胞色素P450酶系在药物代谢中的作用

该文从细胞色素P450概述、参与药物代谢的人类细胞色素P450亚型、细胞色素P450与药物的相互作用、细胞色素P450多态性在药物不良反应中的作用及细胞色素P450酶系产生药物不良反应的机制等方面综述细胞色素P450酶系对药物代谢的影响，为指导临床合理用药，避免药物不良反应及个体化用药提供参考。     

炎症反应过程中药物转运体调控的研究进展

炎症状态下机体对药物的处置过程会发生显著改变,众多药物代谢酶及转运体的表达和功能发生下调。研究表明机体在该状态下会释放一系列炎症细胞因子对药物代谢酶的表达和功能产生调控,而近年来的研究表明在炎症状态下药物转运体也受到这些细胞因子的调控,且部分转运体的调控呈现明显的种属差异性。进一步的机制研究表明,一些转录因子在调控的信号通路中发挥了重要的作用。本文对炎症状态下药物转运体的调控研究进展进行综述。     

食物对细胞色素P450药物代谢酶的影响

细胞色素P450酶系在大多数内源性和外源性分子的生物氧化过程中发挥重要的作用,尤其在药物代谢方面。CYP450酶个体差异大,除了遗传因素的影响外,食物等外界因素也可能影响其活性或表达,从而影响经酶代谢药物的疗效和不良反应。故本文就食物因素对细胞色素P450酶影响的相关研究进行综述。     

槲皮素对药物代谢酶调控作用的研究进展

摘 要 目的： 综述近年来槲皮素对药物代谢酶的影响的研究进展。方法: 查阅近年来国内外报道中槲皮素对药物代谢酶的影响的文献,并进行归纳、分析、总结。结果: 槲皮素通过对Ⅰ相药物代谢酶细胞色素P450（cytochrome P450, CYP）和Ⅱ相药物代谢酶尿苷二磷酸-葡萄糖醛酸转移酶（UDP-glucuronosyltransferase,UGTs）,硫酸基转移酶（sulfotransferase, SULTs）和谷胱甘肽S 转移酶（glutathione S transferase,GSTs）等的调控作用,从而影响多种常用药物在体内、外的代谢。同时,槲皮素对代谢酶的调控作用需要各种核受体的参与。结论:槲皮素对多种药物代谢酶均具有抑制或诱导作用,因此槲皮素将与其他药物发生相互作用。     

中成药对细胞色素P450酶的影响

通过参阅大量近年来国内外有关中成药对药物代谢酶细胞色素P450酶影响的文献,对中成药对细胞色素P450酶的研究的文献进行整理和分析.发现一些中成药对细胞色素P450酶确实存在不同程度的抑制或诱导作用.因此深入研究中成药对细胞色素P450酶活性的影响,既有助于指导中成药在临床上的合理使用以避免因药物相互作用导致的不良反应...     

细胞色素P450酶系和药物的不良反应

细胞色素P450酶系在药物代谢中扮演了重要角色.本文描述了许多环境的和基因的因素,这些因素调整人体酶和它们的药物底物的活性.在一些情况下,细胞色素P450酶具有基因的多态性,导致对某些药物在表型上明显慢和明显快的代谢.慢代谢者(PMs)易发生与浓度相关的药物不良反应,而快代谢者(EMs)则对药物相互作用易感;其中抑制的相互作用可能会由于血浆浓度的增加而导致毒性.药物代谢被改变是药物不良反应的重要原因.     

细胞色素P450靶向抗肿瘤药物研发进展

细胞色素P450酶能催化各种内源性及外源性化合物的代谢,与多种肿瘤的发生发展有着密切关系,因此细胞色素P450酶靶向药物的研制已成为肿瘤治疗的新的研究方向之一,其中肿瘤特异性表达细胞色素P450酶成为研究热点。综述细胞色素P450酶靶向抗肿瘤药物研发进展,并介绍细胞色素P450 2W1及其靶向药物的研究近况。     

细胞色素P450酶系和药物不良反应

细胞色素P450酶系在药物代谢中扮演了重要角色。本描述了许多环境和基因的因素,这些因素调整人体酶和它们的药物底物的活性。在一些情况下,细胞色素P450酶具有基因的多态性,导致对某些药物在表型上明显慢和明显快的代谢。慢代谢（PMs）易发生与浓度相关的药物不良反应,而快代谢（EMs）则对药物相互作用易感;其中抑制的相互作用可能会由于血浆浓度的增中而导致毒性。药物代谢被改变是药物不良反应的重要原因。     

Effects of interleukin 1β (IL-1β) and IL-1β/interleukin 6 (IL-6) combinations on drug metabolizing enzymes in human hepatocyte culture

Exposure to cytokines can down-regulate hepatic cytochrome P450 enzymes. Accordingly, relief of inflammation by cytokinetargeted drug therapy has the potential to up-regulate cytochrome P450s and thereby increase clearance of co-administered drugs. This study examined the effects of the inflammatory cytokine, interleukin 1β (IL-1β), and IL-1β/interleukin 6 (IL-6) combinations on drug metabolizing enzymes in human hepatocyte culture. Treatment of hepatocytes with IL-1β revealed suppression of mRNA expression of several clinically important cytochrome P450 isoenzymes, with EC50 values that differed by isoenzyme. Suppression of CYP1A2 activity by IL-1β could not be measured in 3 of 5 donors due to lack of response, and in the two remaining donors the average EC50 was 450 pg/mL. CYP3A activity had an EC50 of suppression of 416 ± 454 pg/mL. Measurable EC50s were obtained for all 5 donors for CYP2C8, 3A4, 3A5, 4A11 and IL-6R mRNA with fold differences which varied between 9.5-fold (CYP2C8) to 109-fold (CYP4A11). When hepatocytes were treated with IL-1β and IL-6 in combination at concentrations which ranged from 1-100 pg/mL, IL-6 was the main determinant of increases in acute phase response marker mRNA and of decreases in CYP3A4 mRNA. There was no synergy between IL-1β and IL-6 in the regulation of cytochrome P450 mRNA when dosed in combination, although the effects of the two cytokines in combination were additive in certain instances. These data indicate that IL-1β and IL-6 both suppress cytochrome P450 mRNA and enzyme levels in vitro and that, at similar physiologically-relevant concentrations in vitro, IL-6 is more potent than IL-1β.     

非甾体抗炎药药物代谢酶多态性的研究进展

非甾体抗炎药(NAIDs)是一类具有解热、镇痛和抗炎作用的药物,临床上用于治疗骨关节炎、类风湿关节炎等疾病,疗效确切但常伴有胃肠道不适等不良反应,其产生与其药物代谢酶的遗传多态性有关.参与NSAIDs氧化代谢的细胞色素P450酶系,主要有CYP2C9、CYP1A2、CYP2E1和CYP3A4,本文就NSAIDs的药物代谢酶及其多态性和P450代谢的部分NSAIDs(双氯芬酸、布洛芬、氟比洛芬、萘普生和醋氨芬)等作一综述.     

The role of cytokines in the depression of CYP1A activity using cultured astrocytes as an in vitro model of inflammation in the central nervous system.

The interaction and modulation of hepatic cytochrome P450 enzymes by infection and inflammation has been well described both in clinical settings and in animal models. Recent evidence found that inflammation in the central nervous system (CNS) leads to alterations in cytochrome P450 activity in both brain and liver. The bacterial endotoxin lipopolysaccharide (LPS) was used to induce an inflammatory response in cultured astrocytes as a model of CNS inflammation. This inflammatory response involves a range of immune mediators, such as acute phase cytokines, nitric oxide, prostanoid products, and reactive oxygen species. It is hypothesized that cytokines, released during inflammation, act to modulate the expression of specific isoforms of cytochrome P450 resulting in altered activity levels. High levels of the cytokines tumor necrosis factor-alpha and interleukin-1beta were released into culture medium after the addition of LPS to astrocyte cultures. When these same cytokines were added directly to the cultures, they also were able to modulate levels of CYP1A activity. The concurrent addition of dexamethasone to astrocytes blocked both the cytokine release and the alteration of CYP1A activity, thus supporting a role for these cytokines in this response. These results provide evidence suggesting an involvement of acute phase cytokines in mediating the LPS-induced depression of CYP1A activity in cultured astrocytes.     

Expression of UDP-glucuronosyltransferase isoform mRNAs during inflammation and infection in mouse liver and kidney.

Inflammation or infection down-regulates the activity and expression of cytochrome P450 (P450) enzymes involved in hepatic drug clearance, possibly altering drug effectiveness and leading to toxicity. The regulation of UDP-glucuronosyltransferases (UGTs) in inflammation and infection is less well characterized. To determine the response of hepatic and renal UGTs during inflammation and infection, mice were administered either saline or 1 mg/kg lipopolysaccharide (LPS) (16 h), or Citrobacter rodentium by oral gavage (6 days). Hepatic mRNA expression of UGT1A1, 1A9, and 2B5 was similarly down-regulated after LPS exposure and C. rodentium infection, whereas UGT1A2 and 1A6 mRNAs were unchanged. Effects of C. rodentium infection did not require a functional Toll-like receptor 4. Conversely, renal UGT isoforms were relatively unaffected, except for UGT2B5 induction after LPS treatment. Regulation of UGTs during the inflammatory response exhibits similarities to and differences from regulation of P450s, and may be cytokine-mediated.     

DNA甲基化在药物效应和新药研发中的研究进展

DNA甲基化对药物作用的影响日渐受到关注。许多编码药物代谢酶、药物转运体、核受体及药物靶点的基因受DNA甲基化调控。DNA甲基化在影响细胞色素P450酶(CYP450)的表达水平上起着重要的作用,而CYP450酶系催化多种药物代谢反应,能显著影响药物疗效。目前的研究也发现DNA甲基化水平在个体间的差异与药物疗效和不良反应在个体间的差异是紧密相关的。DNA甲基化状态会受药物作用影响,进而引起不同程度的药物不良反应。近年来,以DNA甲基化为靶向的药物研发呈增长态势,DNA甲基转移酶抑制剂对肿瘤等重大疾病治疗具决定性作用。临床试验结果显示,DNA甲基化药物治疗已在改善药物疗效、稳定药理作用及减少药物不良反应上初见成效。DNA甲基化可能成为早期预测药物效应的潜在生物标记,将成为实现临床个体化用药的有力工具。     

Expression and regulation of drug metabolizing enzymes in an immortalized rat hepatocyte cell line.

A hepatic cell line has been immortalized after simian vacuolating virus 40 infection of adult rat hepatocytes maintained in defined culture conditions. This cell line, designated SVHep B4, expressed nuclear large T antigen, exhibited an extended lifespan (50 subcultures) and had a hepatocyte-like morphology. Expression and regulation of drug metabolizing enzymes were studied in long-term cultures of SVHep B4 cells. Significant activities of phase I and phase II enzymes were detected. gamma-Glutamyltransferase, a marker often increased in neoplastic and dedifferentiated hepatocytes, showed a low activity whereas the hepatospecific enzyme tyrosine aminotransferase was expressed at levels similar to those in liver. Responsiveness of drug metabolizing enzymes to inducers was investigated with phenobarbital, dexamethasone and methylcholanthrene. IIB and IA subfamilies of cytochrome P450 were increased, respectively, by phenobarbital (170%) and methylcholanthrene (500%). Glucuronidation of 1-naphthol was increased by phenobarbital (140%) and 3-methylcholanthrene (160%). Phenobarbital, methylcholanthrene and dexamethasone were found to increase significantly gamma-glutamyltransferase while tyrosine aminotransferase activity was enhanced by dexamethasone. Stable expression and inducibility of drug metabolizing enzymes in long-term cultures of the SVHep B4 cell line demonstrate that immortalization of adult hepatocytes represents a promising tool for drug biotransformation studies in vitro.