In vitro screening of a unique botanical extract collection for herb-drug interaction (HDI) potential

项目摘要 草药-药物相互作用（HDI）是一个重要的公共卫生问题超过四分之一个世纪。 近70%的美国人口服用某种形式的膳食补充剂， 近30%的处方药使用者同时服用植物性膳食补充剂（BDS）。目前 美国市场上有数万种BDS，其中许多含有在美国很少遇到的植物化学物质。 正常饮食。因为这些独特的植物化学物质利用相同的吸收、分布、代谢和 排泄途径作为常规药物，药代动力学介导的HDI（PK-HDI）的机会是 高PK-HDI是指单一或多种植物化学物质调节多种人体药物代谢的药物 酶和/或转运蛋白（DMET），反过来，影响生物转化和处置的同时， 2迄今为止，只有少数植物药似乎对临床相关的PK-HDI构成风险。的 这些，圣约翰草（SJW）是最有问题的，因为它使许多药物无效，诱导他们的 代谢和降低其口服生物利用度。SJW的巨大HDI潜力是由于hyperforin，一种独特的 一种植物化学物质，有效激活一种关键蛋白质核受体（NR），即人类的β-胡萝卜素 异生素受体（hPXR）。与所有NR一样，hPXR上调各种DMET的表达和活性。 来自密西西比大学国家天然产品研究中心（NCNPR）的初步数据 表明其他植物也含有能够激活hPXR沿着其他重要的 NR如芳香烃受体（AhR）和组成型雄烷受体（CAR）。因此，有一个 迫切需要对流行的BDS进行系统筛查，以确定其通过NR激活的PK-HDI风险。同样 重要的是需要适当表征的植物提取物来进行筛选。自1995年以来，NCNPR 已经积累了世界上最大的植物提取物储存库之一。在这篇文章中，我们提出了一个4- 筛选最畅销BDS的激活NR能力的分阶段方法（即，hPXR、AhR、CAR） 使用来自NCNPR储存库的充分表征的乙醇提取物。(1)初始高通量NR筛选 将使用标准的体外技术，使用转染的细胞系。(2)能够激活NR的浸提液 将评估它们上调特定DMET的基因表达和蛋白质功能的能力（例如， CYP1A2、CYP2C9、CYP2C19、CYP3A4、ABCB 1）。 (3)候选提取物中的罪魁祸首植物化学物质将被分离和鉴定。(4)最后，代替小学 人肝细胞培养物、提取物/植物化学物质显示前两次筛选的阳性结果 将使用新的Emulate™人类“肝芯片”技术评估各阶段的PK-HDI风险。为 如果提取物在所有筛查阶段均显示阳性结果，则将向中心提供数据“档案” 天然产品相互作用研究的卓越性，用于确证性分析和未来可能的临床PK- 人类发展指数研究。

PROJECT SUMMARY Herb-drug interactions (HDI) have been a significant public health concern for over a quarter century.1 Such concerns are bolstered by the fact that nearly 70% of the U.S. population takes some form of dietary supplement, and almost 30% of all prescription drug users take botanical dietary supplements (BDS) concomitantly. Currently tens of thousands of BDS are on the U.S. market, many containing phytochemicals rarely encountered in the normal diet. Because these unique phytochemicals utilize the same absorption, distribution, metabolism and excretion pathways as conventional medications, the chance for pharmacokinetic-mediated HDI (PK-HDI) is high. PK-HDI are those in which single or multiple phytochemicals modulate various human drug metabolizing enzymes and/or transporters (DMET) that, in turn, affect the biotransformation and disposition of concurrently administered medications.2 To date, only a few botanicals appear to pose risks for clinically relevant PK-HDI. Of these, St. John’s wort (SJW) is the most problematic as it renders many medications ineffective by inducing their metabolism and reducing their oral bioavailability. SJW’s tremendous HDI potential is due to hyperforin, a unique phytochemical that potently activates a key protein nuclear receptor (NR) known as the human pregnane xenobiotic receptor (hPXR). Like all NRs, hPXR upregulates the expression and activity of various DMET. Preliminary data from the University of Mississippi’s National Center for Natural Products Research (NCNPR) indicates that other botanicals also harbor phytochemicals capable of activating hPXR along with other important NRs like the aromatic hydrocarbon receptor (AhR) and constitutive androstane receptor (CAR). Thus, there is a critical need for systematic screening of popular BDS to determine their PK-HDI risk via NR activation. Equally important is the need for properly characterized botanical extracts in which to screen. Since 1995, the NCNPR has amassed one of the world’s largest botanical extract repositories. In this grant submission, we propose a 4- phased approach to screen 30 of the top-selling BDS for their ability to activate NRs (i.e., hPXR, AhR, CAR) using well-characterized ethanolic extracts from the NCNPR repository. (1) Initial high throughput NR screenings will utilize standard in vitro techniques employing transfected cell lines. (2) Extracts capable of activating NRs will be assessed for their ability to upregulate both gene expression and protein function for specific DMET (e.g., CYP1A2, CYP2C9, CYP2C19, CYP3A4, ABCB1) using standard human hepatoma and intestinal cell assays. (3) Culpable phytochemicals within candidate extracts will be isolated and identified. (4) Finally, in lieu of primary human hepatocyte cultures, extracts/phytochemicals exhibiting positive results from the first two screening phases will be evaluated for their PK-HDI risk using the novel Emulate™ human “Liver-on-Chip” technology. For extracts exhibiting positive results in all screening stages, a data “dossier” will be provided to the Center of Excellence for Natural Product Interaction Research for confirmatory analyses and possible future clinical PK- HDI studies.