大蒜对药物代谢酶及转运体活性影响研究进展

作为天然药物的一种,大蒜包含多种具有药理活性的有效成分,在临床应用日益广泛。然而,大蒜长期应用,可能对肝脏药物代谢酶及体内药物转运体的活性产生诱导或抑制效应,从而引起自身或其他合用药物代谢的改变和导致药物相互作用的发生。     

姜黄素对药物代谢酶和转运体影响的研究进展

姜黄素(curcurmin,Cur)是传统药物姜黄的主要有效成分,生活中可作为调料和食物染色剂。大量研究证明姜黄素有许多重要的生物学作用,包括抗炎、抗氧化、抗癌、促进伤口愈合、防治心血管疾病和神经系统退变性疾病等[1-2],     

药物转运体与代谢酶间的协作关系对肠肝药物处置的影响

药物转运体和代谢酶均为机体处置药物的关键蛋白,且大部分药物的体内处置过程需要药物转运体和代谢酶的共同参与。近年来研究发现,药物转运体与代谢酶间存在协作关系,且药物转运体和代谢酶功能的变化可影响其协作处置药物的能力。因此,明晰药物转运体与代谢酶间的协作关系及规律,对于探究药物体内过程,药效和不良反应具有重要的意义。肠和肝是药物发生代谢的主要组织,且其分布有丰富的药物转运体和代谢酶,为此,本文综述了药物转运体和代谢酶间的协作关系对肠肝药物处置的影响。     

雷公藤对药物代谢酶和转运体的调控作用研究进展

目的：综述近年来雷公藤对药物代谢酶及转运体的调控进展。方法：查阅近年来国内外报道中雷公藤对药物代谢酶及转运体调控的文献,并进行归纳总结。结果：雷公藤可以抑制CYP3A4、CYP2C11等多种Ⅰ相代谢酶体外活性。而在体内实验中,大剂量的雷公藤可以强抑制CYP3A、并诱导CYP2C11和CYP2E1的表达。雷公藤对UGT1A6、UGT2B7以及GST也有抑制,但可以诱导Nrf2基因的表达。此外,雷公藤对P-gp和MDR1的基因表达存在抑制作用。结论：雷公藤对多种药物代谢酶和转运体具有抑制或诱导作用,因而雷公藤可能与其他药物发生相互作用。     

大黄酸对药物转运体和代谢酶影响的研究进展

药物转运体和药物代谢酶是影响药物体内处置过程中至关重要的因素。大黄酸作为传统中药大黄的主要活性成分,具有广泛药理活性。研究发现,大黄酸与药物转运体和代谢酶密切相关,能够直接激活或抑制多种转运体的功能及其蛋白表达。而且大黄酸对药物代谢酶细胞色素P450（CYP450）的功能及其蛋白表达同样有抑制作用。因此,大黄酸与其他药物合用时,可能发生基于药动学的药物相互作用（drug-drug interaction,DDI）。从药物转运体和代谢酶的体内分布、大黄酸对转运体及代谢酶的影响等方面进行综述。     

代谢酶和转运体介导的药食同源中药中黄酮类成分对其他药物的影响

目的:综述代谢酶和转运体介导的药食同源中药中黄酮类成分对其他药物的影响,为临床合理用药提供参考.方法:介绍药食同源中药中常见的黄酮类成分,总结代谢酶和转运体对药物在人体内吸收和代谢过程中的作用,并对代谢酶和转运体介导的药食同源中药中常见黄酮类成分对其他药物的影响进行综述.结果 与结论:药食同源中药中的槲皮素、山柰酚、木...     

肠道药物转运体对药物吸收的研究进展

药物与体内各种转运体的相互作用是药物体内药动学性质的决定性因素之一。本文从肠道转运体出发,介绍了它们在药物吸收过程中的作用,旨在利用肠道转运体的作用增加药物向组织器官的靶向分布;利用转运体的作用改变药物的消除途径,从而减轻其毒副作用;利用转运体的作用进行新药设计从而避免药物间有害相互作用的产生;最后通过构建转运体的高通量筛选系统模型,进行新化合物筛选和候选药物的药动学机制研究,为新药的开发和临床合理化给药提供新的策略和思路。     

microRNA介导低氧对药物代谢酶和转运体的调控

低氧条件下机体的循环系统、神经系统、内分泌系统等的功能发生显著改变,这些变化影响药物在体内的吸收、分布、代谢和排泄。药物代谢酶和转运体是影响药物代谢的主要因素,微小RNA (microRNA, miRNA)除调控与药物代谢相关的基因如缺氧诱导因子、炎症因子、核受体等,还可直接作用于药物代谢酶和转运体,影响药物的体内代谢。本文通过综述低氧对miRNA及药物代谢酶和转运体的调节, miRNA调控药物代谢酶和转运体及药物代谢相关基因,低氧调节药物代谢酶和转运体的相关机制等,探讨miRNA在低氧调节药物代谢酶和转运体中的作用,提出以miRNA为核心的低氧影响药物代谢的分子机制。     

黄酮类化合物在原代肝细胞上的代谢和药物相互作用研究进展

黄酮类化合物是一类结构相关的多酚类化合物，已鉴定的黄酮类化合物超过5000种，广泛分布于自然界中。黄酮类化合物主要是指基本母核为2-苯基色原酮（2-phenyl—chromone）的衍生物，现在则是泛指两个具有酚羟基的苯环（A环与B环）通过中央三碳原子相互联结而成的一系列化合物。根据中央三碳链的氧化程度、B环连接位置（2-或3-位）以及三碳链是否构成环状等特点，可将主要天然黄酮类化合物分为黄酮、黄酮醇、二氢黄酮、二氢黄酮醇、异黄酮、二氢异黄酮、查耳酮、二氢查耳酮、花色素、黄烷醇（黄烷-3-醇、黄烷．3，4-二醇）、橙酮、双苯吡酮和高异黄酮等。     

转运体和核受体影响药物代谢的研究进展

转运体是存在于体内几乎所有器官上的有转运功能的蛋白,对药物在体内的吸收、分布、代谢和排泄有非常重要的作用.而核受体是存在于细胞内的配体依赖性转录因子,可以激活配体影响代谢酶和转运体的表达和活性,进而影响药物在机体内代谢.本文综述了转运体和核受体家族中几个重要的成员以及它们对药物代谢影响的研究进展.     

肾脏转运体和/或代谢酶介导药物排泄及药物相互作用的研究进展

肾脏是人体最重要的排泄器官。肾单元近端小管细胞具有多种药物转运体和代谢酶,在药物及其代谢物处置中发挥关键作用。近端小管细胞中主要转运体包括有机阴离子转运体、有机阳离子转运体、有机阳离子/肉毒碱转运体、多药及毒素外排转运蛋白、P-糖蛋白、乳腺癌耐药蛋白和多药耐药相关蛋白;主要代谢酶包括细胞色素P450酶,UDP-葡萄糖醛酸基转移酶、磺酸基转移酶、谷胱甘肽S-转移酶。肾脏转运体和/或代谢酶介导药物相互作用(DDIs)是临床关注的重要问题。肾脏转运体和代谢酶存在密切协作关系,在肾脏也存在多种相互作用现象(包括转运-转运相互作用,代谢-代谢相互作用和转运-代谢相互作用),其显著影响药物肾脏处置、临床疗效和肾毒性。本文系统阐述了这些相互作用对药物及其代谢物的肾脏排泄、药动学、DDIs和肾毒性的影响。今后需要进一步阐明肾脏转运-代谢相互作用机制,将有助于研究体内药物肾脏处置和DDIs,促进临床合理用药。     

Linezolid absolute bioavailability and the effect of food on oral bioavailability.

Linezolid is a novel oxazolidinone antibiotic that has a spectrum of activity encompassing a variety of Gram-positive bacteria. The objectives of this study were twofold: (1) to compare the absorption of linezolid tablets given immediately following a high-fat meal with the absorption of tablets administered while fasting, and (2) to assess the bioavailability of a 375-mg oral dose given while fasting relative to a 375-mg dose of linezolid sterile solution given intravenously. Venous blood samples were taken over the 48 h following the single dose administration of both the oral and intravenous (IV) treatment. Samples were subsequently frozen for the determination of linezolid concentrations by HPLC. The only statistically significant difference between the fasted and the fed treatment was in peak plasma concentration, with the mean C(max) for fasted subjects being 23% greater than that for subjects after consumption of a high-fat meal. Comparable AUC(0-infinity) values were measured under both conditions, indicating that the overall extent of absorption is the same. Therefore, the difference in C(max), while statistically significant, should not affect the therapeutic efficacy of linezolid when it is administered with food. There were no statistically significant differences in AUC(0-infinity), CL or half-life between the fasted oral treatment and the intravenous treatment. As expected, C(max) was statistically different between the two treatments. However, the mean absolute bioavailability (F) of the tablet, using the IV sterile solution as the reference treatment, was 103% (+/-20%).     

Role of glucose transporters in the intestinal absorption of gastrodin,a highly water-soluble drug with good oral bioavailability

Abstract

Gastrodin, a sedative drug, is a highly water-soluble phenolic glucoside with poor liposolubility but exhibits good oral bioavailability. The current study aims to investigate whether glucose transporters (GLTs) are involved in the intestinal absorption of gastrodin. The intestinal absorption kinetics of gastrodin was determined using the rat everted gut sac model, the Caco-2 cell culture model and the perfused rat intestinal model. In vivo pharmacokinetic studies using diabetic rats with high GLT expression were performed. Saturable intestinal absorption of gastrodin was observed in rat everted gut sacs. The apparent permeability (Papp) of gastrodin from the apical (A) to basolateral (B) side in Caco-2 cells was two-fold higher than that from B to A. Glucose or phlorizin, a sodium-dependent GLT (SGLT) inhibitor, reduced the absorption rates of gastrodin from perfused rat intestines. In vivo pharmacokinetic studies showed that the time of maximum plasma gastrodin concentration (T_max) was prolonged from 28 to 72?min when orally co-administered with four times higher dose of glucose. However, the T_max of gastrodin in diabetic rats was significantly lowered to 20?min because of the high intestinal SGLT1 level. In conclusion, our findings indicate that SGLT1 can facilitate the intestinal absorption of gastrodin.     

Mechanisms and variations in the food effect on propranolol bioavailability

Summary Mechanisms and variations in the food-induced increase in the bioavailability of propranolol were assessed by single-dose (80 mg) studies in healthy volunteers who took the drug on an empty stomach, immediately after a protein-rich breakfast, and together with a carbohydrate-rich, protein-poor breakfast. Concomitant intake of the protein-rich, but not the carbohydrate-rich, protein-poor breakfast, increased the bioavailability of propranolol in most, but not all, subjects. The food (protein) effect displayed much inter-individual variation, from a decrease to a 250% increase, which could be explained, at least in part, by a correlation between the oral clearance of propranolol and the food-induced increase in its bioavailability. The food effect was not associated with decreased total availability, but with delayed appearance, of the oxidative metabolites 4-OHP, NLA and PG. Hence the food (protein) effect does not seem to be caused by enzyme inhibition, but rather it is due to reduced hepatic extraction of propranolol, probably consequent to an increased hepatic entry rate. When taken together with the protein-rich breakfast, propranolol usually appeared in systemic blood at least as early as when taken on an empty stomach, implying that gastric absorption of propranolol may be possible in the presence of protein-rich food. Within the individual the food effect was reproducible, but its magnitude showed an intraindividual variation that may reflect its dependence upon the rates of gastrointestinal absorption and splanchnic-hepatic blood flow, and hence upon the rate of hepatic drug entry.     

Influence of intestinal efflux pumps on the absorption and transport of furosemide

Purpose

Furosemide is a commonly used diuretic which is used in the treatment of edema, congestive heart failure, hypertension and renal failure. Its absorption exhibits inter- and intra-subject variability that can be attributed to many factors including the intestinal efflux pumps such as the P-glycoprotein (P-gp). This study was done due to the great disagreement between what is published in the literature regarding the influence of P-gp on furosemide and at the same time due to the importance of this drug in the treatment of different conditions as described above. In addition, an investigation of the effect of two of the commonly used pharmaceutical excipients (hydroxypropyl β-cyclodextrin [HPβCD] and Tween 80) and also a P-gp inhibitor (verapamil hydrochloride) on the intestinal absorption of this drug were also done.

Methods

The study utilized the everted intestinal sacs technique to investigate both the effect of the efflux transporter (P-gp) on furosemide absorption and also the effect of the chosen excipients.

Results

The absorption of furosemide was significantly influenced by the P-gp as confirmed by the everted vis the non-everted sacs together with the verapamil study in which the transport of furosemide was inhibited by verapamil. In addition, Tween 80 was also shown to inhibit the P-gp pump whereas the HPβCD did not significantly influence the efflux of furosemide in this study.

Conclusions

P-glycoprotein and some of the used excipients in the formulation play a very important role in the transport of furosemide and other drugs. Thus excipients that affect the activity of P-gp should be avoided when formulating drugs that are substrate for the P-gp or other efflux pumps.     

Inducing effect of feprazone on hepatic drug-metabolizing enzymes in man

Summary The inducing effect of feprazone, a pyrazolone anti-inflammatory agent, on hepatic drug-metabolizing enzymes has been studied in healthy volunteers. The ratio of 6-hydroxycortisol (6-OHF) to 17-hydroxycorticosteroids (17-OHCS) in urine, used as an indicator of oxidative drug-metabolizing enzyme activity, was increased up to 1.6-times the original level after 5 days of oral treatment with feprazone 300 mg/day. This indicates that feprazone induces hepatic drug-metabolising enzymes in man as does phenylbutazone.     

Triglyceride-mimetic prodrugs of scutellarin enhance oral bioavailability by promoting intestinal lymphatic transport and avoiding first-pass metabolism

The intestinal capillary pathway is the most common way to absorb oral drugs, but for drugs with poor solubility and permeability and high first-pass metabolism, this pathway is very inefficient. Although intestinal lymphatic transport of lipophilic drugs or prodrugs is a promising strategy to improve the oral delivery efficiency of these drugs. The prodrug strategy for modifying compounds with Log P > 5 to promote intestinal lymphatic transport is a common approach. However, transport of poor liposoluble compounds (Log P < 0) through intestinal lymph has not been reported. Herein, triglyceride-mimetic prodrugs of scutellarin were designed and synthesized to promote intestinal lymphatic transport and increase oral bioavailability. Lymphatic transport and pharmacokinetic experiments showed that two prodrugs did promote intestinal lymphatic transport of scutellarin and the relative oral bioavailability was 2.24- and 2.45-fold of scutellarin, respectively. In summary, triglyceride-mimetic prodrugs strategy was used for the first time to study intestinal lymphatic transport of scutellarin with Log P < 0, which could further broaden the application range of drugs to improve oral bioavailability with the assistance of intestinal lymphatic transport.     

镉、铅、汞对苯巴比妥诱导肝微粒体药物代谢酶的影响

一次ip醋酸镉2.4mg/kg、醋酸铅100mg/kg或氯化汞 2.0 mg/kg均可抑制大鼠肝微粒体药物代谢酶。上述处理还可明显降低苯巴比妥对肝微粒’乙基吗啡N-脱甲基化酶、氨基比林N-脱甲基化酶、苯胺羟化酶和环己巴比妥羟化酶活力的诱导作用,降低苯巴比妥对细胞色素P450和细胞色素 b_5以及微粒体蛋白合成的诱导作用。结果提示镉、铅、汞可能通过降低微粒体酶的新生合成,抑制肝微粒体药物代谢酶。     

银杏黄酮类物质抗肿瘤作用初探

目的探测银杏黄酮类物质的抗肿瘤作用。方法微核检测法测定银杏黄酮对致畸作用的防护;H3标记法检测银杏黄酮对体外培养的YAC-I细胞增殖的影响;原位注射法检测银杏黄酮对小鼠体内S-180实体瘤生长的影响。结果银杏黄酮处理组小鼠的微核率明显低于对照组,抑核率为48.23%;YAC-I细胞在银杏黄酮作用24h和48h后,增殖受到明显抑制,浓度为2500μg/ml时,增殖基本停滞;荷瘤小鼠在接受原位注射银杏黄酮后,肿瘤生长受到明显抑制,抑瘤率为56.99%。结论银杏黄酮可防护环磷酰胺的致畸作用;对体内体外肿瘤细胞的增殖均具抑制作用。