Kratom alkaloids: in vitro and in vivo pharmacological mechanisms

卡痛生物碱：体外和体内药理机制

• 批准号: 10493516
• 负责人: Christopher R McCurdy
• 金额: $ 7.27万
• 依托单位: UNIVERSITY OF FLORIDA
• 依托单位国家: 美国
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-04-15 至 2024-02-29
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10493516
• 关键词: Adrenergic Receptor; Alkaloids; Animals; Applications Grants; Behavioral; Binding; Biological; Biological Assay; Brain; Chemicals; Complex; Computer Models; Dose; Drug Kinetics; Drug usage; Enzymes; Female; Gold; Heroin; In Vitro; Individual; Liver; Liver Microsomes; Mediating; Metabolism; Methods; Mitragyna; Natural Products Chemistry; Opioid; Opioid Receptor; Parents; Pathway interactions; Pharmaceutical Preparations; Pharmacodynamics; Pharmacology; Plant Leaves; Plants; Plasma; Rattus; Recombinants; Risk; Self Administration; Source; Stimulus; System; Testing; Toxic effect; Training; Translations; Trees; United States Food and Drug Administration; Urine; abuse liability; antagonist; base; capsule; drug discrimination; in vivo; inhibitor; male; non-opioid analgesic; opioid abuse; pharmacokinetics and pharmacodynamics; receptor; sex

ABTSRACT Mitragyna speciosa (kratom) has exploded onto the US market, with an estimated 55,000 kg entering the US between 2014 and 2016, corresponding to 12 million kratom doses and one million users. The FDA recently used computational modeling to predict that 22 kratom constituents bind to opioid receptors; however, these predictions await translation into whole animals. There is an urgent need for systematic, pharmacological testing of kratom alkaloids to help inform abuse risk. We feel it is important to assess the behavioral effects of not only individual alkaloids, but also alkaloid mixtures representative of plant material in commercially used products. We will extract, isolate, and purify alkaloids from two kratom sources: dried leaf material of Mitragyna speciosa trees and a US commercial product (i.e., OPMS Gold capsules). We will quantify up to ten kratom alkaloids simultaneously using our bioanalytical methods. In a pharmacokinetic-based Aim 1, we will quantify kratom alkaloids in multiple biological matrices (urine, plasma, brain, liver) after p.o. and i.v. administration in rats to obtain a comprehensive ADME profile. Liver microsomes, recombinant CYP450 enzymes, and specific chemical CYP450 inhibitors will be used to identify pathways of metabolism and biologically active metabolites. In our pharmacodynamic-based Aim 2, we will use drug discrimination to identify receptor mechanism(s) underlying abuse-related effects. Four separate groups of rats will be trained to discriminate one of the following: 1) alkaloid mixture in proportion to kratom dried leaf material, 2) alkaloid mixture in proportion to commercially available kratom product (both containing 32 mg/kg mitragynine, 3) 32 mg/kg mitragynine alone, or 4) 3.2 mg/kg 7- hydroxymitragynine alone. Moreover, we will use i.v. drug self-administration to assess abuse risk, and to assess how kratom alkaloids modify the reinforcing effects of abused opioids (i.e., heroin). Male and female rats will be used throughout to assess sex as a biological variable. The overarching hypothesis is that Mitragyna speciosa has a complex pharmacology resulting from multiple alkaloids differentially interacting with both opioid and non- opioid receptors. The following specific hypotheses will be tested: 1) alkaloids interact (i.e., exert synergistic and antagonist effects) with each other and with other abused opioids in drug discrimination and self-administration assays; 2) some of the interactions are due to PK; 3) behavioral effects of the parent alkaloid are due in part to both the parent compound and its behaviorally active metabolites; 4) no single alkaloid accounts for the discriminative stimulus and reinforcing effects of the mixtures; and 5) both opioid and adrenergic receptors mediate the effects of alkaloid mixtures representative of natural plant material. Subtraction and addition of individual alkaloids will help identify the alkaloids most responsible for kratom's integrated pharmacology. After 5 years, we expect to demonstrate that kratom alkaloids exert differential effects through multiple receptor systems, and we further expect to identify key pharmacological mechanisms responsible for the widespread use of kratom.

ABTSRACT Mitragyna spiosa (kratom) 已在美国市场爆发，估计有 55,000 公斤进入美国 2014 年至 2016 年间，相当于 1200 万剂卡痛叶和 100 万用户。 FDA最近 使用计算模型预测 22 种 kratom 成分与阿片受体结合；然而，这些 预测有待转化为整个动物。迫切需要系统的药理学测试 卡痛生物碱有助于了解滥用风险。我们认为评估行为影响很重要，不仅是 单独的生物碱，以及商业使用产品中代表植物材料的生物碱混合物。 我们将从两种卡痛来源中提取、分离和纯化生物碱：帽柱木的干燥叶材料 树木和美国商业产品（即 OPMS Gold 胶囊）。我们将量化多达十种卡痛生物碱 同时使用我们的生物分析方法。在基于药代动力学的目标 1 中，我们将量化卡痛叶 口服后多种生物基质（尿液、血浆、脑、肝）中的生物碱和静脉注射给大鼠施用 获取全面的 ADME 配置文件。肝微粒体、重组 CYP450 酶和特定化学物质 CYP450 抑制剂将用于识别代谢途径和生物活性代谢物。在我们的 基于药效学的目标 2，我们将使用药物辨别来识别潜在的受体机制 与滥用相关的影响。将训练四组不同的大鼠来区分以下其中一项：1) 生物碱 与卡痛干叶材料成比例的混合物，2)与市售品成比例的生物碱混合物 卡痛叶产品（均含有 32 mg/kg 帽柱木碱，3）单独使用 32 mg/kg 帽柱木碱，或 4）3.2 mg/kg 7- 单独使用羟基帽柱木碱。此外，我们将使用静脉注射。药物自我管理以评估滥用风险，并评估 卡痛叶生物碱如何改变滥用阿片类药物（即海洛因）的增强作用。雄性和雌性大鼠将 自始至终都用来评估性别作为一个生物变量。总体假设是 Mitragyna spiosa 由于多种生物碱与阿片类药物和非阿片类药物有不同的相互作用，因此具有复杂的药理学作用 阿片受体。将测试以下具体假设：1）生物碱相互作用（即发挥协同作用和 药物歧视和自我给药中相互之间以及与其他滥用阿片类药物之间的拮抗作用） 化验； 2）部分交互是由于PK； 3) 母体生物碱的行为效应部分归因于 母体化合物及其行为活性代谢物； 4）没有单一的生物碱可以解释 混合物的区别刺激和强化作用； 5) 阿片受体和肾上腺素受体 介导代表天然植物材料的生物碱混合物的作用。减法和加法 单个生物碱将有助于识别对卡痛叶综合药理学最重要的生物碱。后 5年，我们期望证明卡痛叶生物碱通过多种受体发挥不同的作用 系统，我们进一步期望确定导致广泛使用的关键药理学机制 卡痛叶。