Caco-2细胞模型在药物研究中的应用

近年来,利用人结肠癌上皮细胞Caco-2（Human cocloncarcinoma cell lines）模型在药物研究方面取得了令人鼓舞的进展。由于药物透过Caco-2单细胞层的体外过程与药物口服后在肠中的吸收和代谢有良好的相关性,该模型已广泛用于药物在吸收、转运、代谢等方面的研究,现就Caco-2细胞模型在药物研究中的应用作一综述。     

体外Caco-2细胞模型在药物吸收中的应用进展

目的:介绍Caco-2细胞模型的特征及其在药物吸收中的应用.方法:分析国内外近期相关文献,对Caco-2细胞模型在药物吸收动力学中的研究进行概述.结果:Caco-2细胞模型用于药物动力学研究,可预测药物在体内的吸收和代谢.结论:体外Caco-2细胞模型在药物吸收过程的研究中有重要意义.     

Caco-2细胞模型在药物体外研究中的应用

Caco-2细胞模型是一种筛选药物离体口服特性的模型,已广泛用于评价药物在小肠的吸收特性和各种转运机制的研究.现综述Caco-2细胞单层模型的基本特点及其在药物的小肠吸收、代谢以及高通量筛选等方面的应用.     

Caco-2细胞模型在天然药物吸收研究中的应用

目的Caco-2细胞模型为经典的口服药物体外吸收模型。此文介绍了Caco-2细胞模型的来源与特点,综述了Caco-2细胞模型在天然药物吸收研究中的应用现状,并对Caco-2细胞模型在天然药物研究中的应用前景进行了探讨。     

Caco-2细胞模型在药物吸收研究中的应用

Caco-2细胞(thehumancoloncarcino-maline)模型是最近十几年来国外广泛采用的一种研究药物肠吸收的体外模型,它具有如下优点:与动物试验相比,培养细胞要比培养动物更省时更经济;可测定药物的细胞摄取及胯膜转运;Caco-2细胞内有药物代谢酶,可在有代谢状况下测定药物的胯膜转运;Caco-2细胞易于培养且生命力强;Caco-2细胞来源是人结肠癌细胞,同源性好;可用于区分肠腔内不同吸收途径的差别。1.Caco-2细胞模型建立Caco-2细胞适宜在37℃、含5%CO2的环境中培养,采用DMEM培养基,且在培养基中应含有10%胎牛血清、1%非必需氨基酸、1%谷氨酰胺和青…     

Caco-2细胞模型的改良研究进展

目的:总结近年来Caco-2细胞模型的改良研究进展,以便于广大研究者能在实际研究中更合理地利用该细胞模型。方法:查阅近十年来国内外对Caco-2细胞模型进行改良研究的文献,总结对Caco-2细胞模型进行的改良方法。结果与结论:针对Caco-2细胞局限性的改进工作已经广泛开展,其中包括通过基因重组、基因敲除或化学物质诱导改变细胞内代谢酶和转运蛋白表达,通过细胞共培养或加入黏蛋白来增加黏液层,缩短培养周期,增加药物溶解性和减少非特异性结合等。这些改良使该模型能更好地模拟体内生理条件,使其在研究药物的吸收、代谢及高通量筛选中能发挥越来越重要的作用。     

Cac0-2细胞系及其在药物吸收、代谢中的应用

由于小肠的生理结构适用于药物吸收,所以口服给药是最广泛、最方便的给药途径之一,因此研究药物在肠道的吸收与代谢就显得十分必要.目前用于药物吸收的实验方法主要有:在体肠回流法,肠襻法,分离肠粘膜法、外翻囊法等[1].由于这些方法存在采用动脉组织及其它一些局限性,近年来人们尝试使用人肠细胞培养系统来研究药物在肠道的吸收和代谢,以快速筛选口服药物.Caco-2细胞模型被认为是目前最好的体外吸收模型,可用于快速评估新药的细胞渗透性、阐明药物转运的途径、评价提高膜通透性的方法、确定被动扩散的药物最合适的理化性质和评估新药的潜在毒性作用等,成为药物吸收研究的必备手段.本文就Caco-2细胞及其应用作一简要介绍.     

Caco-2细胞模型的应用进展

Caco-2细胞是预测药物在人小肠吸收的一种重要模型,但由于其与生俱来的不足,其应用曾受到一定限制.近年来,随着细胞生物学和分子生物学的发展,Caco-2细胞模型得到了长足的发展,不仅克服了原始模型的局限性,而且拓宽了在药物研究与开发领域的应用.本文拟将Caco-2细胞模型在药品食品研究中的最新应用进展做一综述.     

隐丹参酮在Caco-2细胞模型中的吸收机制

目的 研究隐丹参酮在Caco-2细胞模型中的吸收机制。方法 用Caco-2细胞单层模型研究隐丹参酮的双向转运，并考察时间、药物浓度及抑制剂对隐丹参酮吸收的影响。用高效液相色谱法检测药物浓度，计算其表观渗透系数。结果 隐丹参酮在Caco-2细胞模型中，从单层细胞层顶端到基底端的转运大于基底端到顶端的转运，随时间和浓度的增加，药物吸收呈饱和趋势，且可被其结构类似物丹参酮Ⅱ。竞争性抑制。结论 隐丹参酮在Caco-2细胞模型中的吸收主要是由载体介导的主动转运，且该主动转运的载体位于Caco-2细胞单层的顶端。     

矢车菊黄素在Caco-2细胞模型中的吸收机制研究

目的 研究矢车菊黄素（centaureidin）在Caco-2细胞单层模型中的吸收机制。方法 以HPLC分析矢车菊黄素浓度,用Caco-2 细胞单层模型评价吸收时间、药物浓度、介质pH值、抑制剂等对矢车菊黄素吸收的影响,研究矢车菊黄素的吸收机制,计算表观渗透系数（apparent permeability coefficient, Papp）。结果 药物的吸收与药物浓度和吸收时间正相关;弱酸性介质条件下有利于药物的吸收;2,4-二硝基酚（DNP）对药物吸收无影响,但异博定（verapamil）可增加药物的吸收;从肠腔侧到基底侧的转运小于基底侧到肠腔侧的转运。结论 矢车菊黄素在Caco-2细胞模型中的吸收主要是被动转运,受P-糖蛋白的外排作用。     

Caco-2细胞模型——药物吸收研究的有效“工具”

吸收过程是决定口服药物生物利用度的重要因素 ,然而很多药物的吸收机制还不明确。Caco 2细胞模型是目前最好的体外吸收模型 ,在药物的吸收过程及吸收机制的研究方面有广泛的应用 ,尤其在中药吸收研究方面 ,Caco 2细胞模型的应用成为目前的热点。另外 ,Caco 2细胞模型在药物代谢方面也有应用。因此 ,Caco 2细胞模型将成为药物吸收研究的重要手段 ,有助于加快新药筛选和开发的速度。     

Caco-2 monolayers in experimental and theoretical predictions of drug transport

This review examines the use of Caco-2 monolayers in the prediction of intestinal drug absorption. First, the different routes of drug transport in Caco-2 monolayers are compared with those seen in vivo. Second, the prediction of drug absorption in vivo from transport experiments in cell monolayers is discussed for different classes of drugs. Finally, the use of Caco-2 monolayers as a reference model in physico-chemical and theoretical predictions of drug absorption is discussed. We conclude that Caco-2 monolayers can be used to identify drugs with potential absorption problems, and possibly also to select drugs with optimal passive absorption characteristics from series of pharmacologically active molecules generated in drug discovery programs.     

Caco-2 monolayers in experimental and theoretical predictions of drug transport

This review examines the use of Caco-2 monolayers in the prediction of intestinal drug absorption. First, the different routes of drug transport in Caco-2 monolayers are compared with those seen in vivo. Second, the prediction of drug absorption in vivo from transport experiments in cell monolayers is discussed for different classes of drugs. Finally, the use of Caco-2 monolayers as a reference model in physico-chemical and theoretical predictions of drug absorption is discussed. We conclude that Caco-2 monolayers can be used to identify drugs with potential absorption problems, and possibly also to select drugs with optimal passive absorption characteristics from series of pharmacologically active molecules generated in drug discovery programs.     

Caco-2细胞模型在口服药物吸收研究中的应用

目的对Caco 2细胞模型在口服药物肠吸收研究中的应用作一综述。方法在引用了自1974~2004年的32篇文献的基础上,通过介绍并比较体外Caco 2模型和体内药物吸收转运的不同途径,讨论Caco 2单层细胞模型在预测不同类药物体内吸收中的作用。结果Caco 2细胞模型可以预测不同转运途径的药物体内吸收,尤其适用于被动转运药物,这一细胞模型在药物吸收机制、处方组成透膜性和黏膜毒性、药物吸收过程中的相互作用、药物的化学结构和体内转运关系、药物吸收限速因素、药物代谢稳定性及pH对药物吸收的影响等研究中均有较广泛的应用。结论Caco2细胞模型用于预测各种途径的药物吸收,在细胞水平上提供了大量与吸收相关的信息,是口服药物高通量筛选的良好工具。     

Comparison of drug transporter levels in normal colon, colon cancer, and Caco-2 cells: impact on drug disposition and discovery

A critical step in early phase drug development is the determination of oral bioavailability. In part, the ability to predict whether a drug will be effectively transported across the gastrointestinal mucosa can be estimated from the physicochemical properties of the compound. Although advancements through rational drug design have more correctly predicted bioavailability, considerable variability remains to be explained. Transporter expression throughout the gastrointestinal tract may explain much of this variation. ATP-binding cassette (ABC) transporters were the first family of transporters identified to modify bioavailability. More recently, the solute carrier family has also been shown to alter the pharmacokinetic profile of drugs. Currently, the Caco-2 human colon carcinoma cell line is often used by the pharmaceutical industry to evaluate intestinal absorption of drugs; however, in vivo/in vitro permeabilities with carrier mediated drugs do not correlate well, suggesting that Caco-2 transporter expression varies from that of the small intestine. With this is mind, we integrated U133A GeneChip expression data from the NCBIs Gene Expression Omnibus (GEO) collection and then compared the expression pattern of Caco-2 cells to normal colon to determine if the Caco-2 cell line is a reliable model for colonic delivery. Furthermore, transporter expression of Caco-2 cells was compared to that of human colon tumors to assess whether this cell line could be useful to predict drug absorption for colon cancer. Our analysis shows that the expression pattern for Caco-2 cells closely resembles the gene expression profile of transporters within the normal colon, suggesting that this cell line may serve as an in vitro model of colonic drug adsorption. However, the molecular "fingerprint" of Caco-2 was distinctly different from tumor samples, indicating that the Caco-2 model would unlikely predict accurate drug absorption for colon cancer sites.     

Caco-2 Cell Monolayers as a Model for Drug Transport Across the Intestinal Mucosa

Human colon adenocarcinoma (Caco-2) cells, when grown on semipermeable filters, spontaneously differentiate in culture to form confluent monolayers which both structurally and functionally resemble the small intestinal epithelium. Because of this property they show promise as a simple, in vitro model for the study of drug absorption and metabolism during absorption in the intestinal mucosa. In the present study, the transport of several model solutes across Caco-2 cell monolayers grown in the Transwell diffusion cell system was examined. Maximum transport rates were found for the actively transported substance glucose and the lipophilic solutes testosterone and salicylic acid. Slower rates were observed for urea, hippurate, and salicylate anions and were correlated with the apparent partition coefficient of the solute. These results are similar to what is found with the same compounds in other, in vivo absorption model systems. It is concluded that the Caco-2 cell system may give useful predictions concerning the oral absorption potential of new drug substances.     

没食子酸对α-葡萄糖苷酶的抑制作用及其降糖机制研究

目的 研究没食子酸对α-葡萄糖苷酶的抑制作用及其抑制类型,探索酚酸类化合物在治疗糖尿病方面的价值及Caco-2细胞模型在筛选降糖药方面的作用.方法 以麦芽糖为底物,采用酶-抑制剂模型和Caco-2细胞模型研究没食子酸对α-葡萄糖苷酶活力的影响,采用Caco-2细胞模型研究没食子酸对葡萄糖吸收的影响.结果 没食子酸对两种模型的α-葡萄糖苷酶均有抑制作用,半数抑制量(IC_(50))为577.5 μg/mL和182.6 μg/mL;250 μg/mL的没食子酸对α-葡萄糖苷酶抑制作用低于同浓度的阿卡波糖(P<0.05).没食子酸是α-葡萄糖苷酶的竞争型抑制剂.没食子酸对葡萄糖吸收有抑制作用.结论 没食子酸对α-葡萄糖苷酶和葡萄糖吸收有一定抑制作用.Caco-2细胞模型在筛选降糖药方面具有重要意义.     

Suitability of the in vitro Caco-2 assay to predict the oral absorption of aromatic amine hair dyes

Oral absorption is a key element for safety assessments of cosmetic ingredients, including hair dye molecules. Reliable in vitro methods are needed since the European Union has banned the use of animals for the testing of cosmetic ingredients. Caco-2 cells were used to measure the intestinal permeability characteristics (P_app) of 14 aromatic amine hair dye molecules with varying chemical structures, and the data were compared with historical in vivo oral absorption rat data. The majority of the hair dyes exhibited P_app values that indicated good in vivo absorption. The moderate to high oral absorption findings, i.e. ≥ 60%, were confirmed in in vivo rat studies. Moreover, the compound with a very low P_app value (APB: 3-((9,10-dihydro-9,10-dioxo-4-(methylamino)-1-anthracenyl)amino)-N,N-dimethyl-N-propyl-1-propanaminium) was poorly absorbed in vivo as well (5% of the dose). This data set suggests that the Caco-2 cell model is a reliable in vitro tool for the determination of the intestinal absorption of aromatic amines with diverse chemical structures. When used in combination with other in vitro assays for metabolism and skin penetration, the Caco-2 model can contribute to the prediction and mechanistic interpretation of the absorption, metabolism and elimination properties of cosmetic ingredients without the use of animals.     

Strategies for absorption screening in drug discovery and development

This review gives an overview of the current approaches to evaluate drug absorption potential in the different phases of drug discovery and development. Methods discussed include in silico models, artificial membranes as absorption models, in vitro models such as the Ussing chamber and Caco-2 monolayers, in situ rat intestinal perfusion and in vivo absorption studies. In silico models such as iDEA can help optimizing chemical synthesis since the fraction absorbed (Fa) can be predicted based on structural characteristics only. A more accurate prediction of Fa can be obtained by feeding the iDEA model with Caco-2 permeability data and solubility data at various pH's. Permeability experiments with artificial membranes such as the filter-IAM technology are high-throughput and offer the possibility to group compounds according to a low and a high permeability. Highly permeable compounds, however, need to be further evaluated in Caco-2 cells, since artificial membranes lack active transport systems and efflux mechanisms such as P-glycoprotein (PgP). Caco-2 and other "intestinal-like" cell lines (MDCK, TC-7, HT29-MTX, 2/4/A1) permit to perform mechanistic studies and identify drug-drug interactions at the level of PgP. The everted sac and Ussing chamber techniques are more advanced models in the sense that they can provide additional information with respect to intestinal metabolism. In situ rat intestinal perfusion is a reliable technique to investigate drug absorption potential in combination with intestinal metabolism, however, it is time consuming, and therefore not suited for screening purposes. Finally, in vivo absorption in animals can be estimated from bioavailability studies (ratio of the plasma AUC after oral and i.v. administration). The role of the liver in affecting bioavailability can be evaluated by portal vein sampling experiments in dogs.