Novel 13-C Tomato Carotenoids for Absorption and Metabolism Studies in Humans

描述（由申请人提供）：在过去十年中，富含类胡萝卜素的西红柿和许多从西红柿中提取的产品被广泛销售，用于促进健康和预防疾病。然而，争议仍然存在，很大程度上是因为人们对主要的番茄类胡萝卜素番茄红素（LYC）、植物烯（PE）和植物流感素（PF）的生物利用度、代谢和作用机制知之甚少。这项拨款申请描述了一种新型研究工具的特征和实施，该工具将极大地提高我们追踪番茄类胡萝卜素代谢物吸收的能力。在本应用中描述和测试的新技术是基于生产13C标记的LYC， PE和PF并在人体中进行测试。这些富含13c的类胡萝卜素将用于交叉饲养研究，旨在更精确地定义和比较番茄类胡萝卜素在男性和女性中的吸收和代谢情况。目的1：利用离体番茄细胞悬浮培养技术制备纯化的13C-植物烯（PE）、13C-植物荧光素（PF）和13C-番茄红素（LYC）。我们将首次应用番茄细胞悬浮培养可靠地生产高纯度非放射性富含13c的番茄类胡萝卜素PE， PF和LYC，用于新的生物利用度和人体代谢研究。具体目标#2：使用13C -PE、13C -PF和13C- lyc，比较和定义男性和女性番茄衍生类胡萝卜素的吸收动力学和相对生物利用度。我们将使用13C-PE、13C-PF和13C-LYC来表征这些番茄类胡萝卜素在健康成年男性（n=12）和女性（n=12）中的摄取动力学和相对生物利用度。特定目标3：通过13C-PE， 13C-PF或13C-LYC，鉴定人类随时间变化的番茄衍生类胡萝卜素代谢物。人类对番茄衍生类胡萝卜素代谢的认识充其量是推测性的，在降解途径和潜在生物活性化合物的产生方面基本上是不存在的。示踪剂标记将允许我们使用HPLC-MS/MS检查口服母体化合物向代谢物的转化，这些代谢物是生物激活途径或分解代谢/降解途径的特征。的意义。只有通过开发新的工具来检查消化、吸收、生物利用度、组织分布和系统与靶组织代谢，我们才能了解LYC、PE和PF对人类健康的作用机制。该提案针对PAR-08-135项目公告，题为“人类补充和替代医学（CAM）研究的探索性/发展性资助”，由国家补充和替代医学中心（NCCAM）， NCI，国家老龄化研究所（NIA）和膳食补充剂办公室（ODS）组成。

DESCRIPTION (provided by applicant): Carotenoid-rich tomatoes and many products derived from tomatoes have been extensively marketed in the last decade for health promotion and disease prevention. Yet, controversy abounds, in large part because so little it known about the bioavailability, metabolism and mechanisms of action of the major tomato carotenoids lycopene (LYC), phytoene (PE) and phytofluene (PF). This grant application describes the characterization and implementation of a novel research tool that will dramatically improve our ability to trace the absorption of metabolites derived from the tomato carotenoids. The new technology, described and tested in this application, is based upon producing 13C labeled LYC, PE, and PF and testing them in humans. These 13C-enriched carotenoids will be used in a cross-over feeding study designed to more precisely define and compare how tomato carotenoids are absorbed and metabolized in men and women. Specific Aim 1: To produce pure 13C- phytoene (PE), 13C- phytofluene (PF) and 13C-lycopene (LYC) by utilizing in vitro tomato cell suspension culture technology. For the first time, we will apply tomato cell suspension culture for the reliable production of highly purified non-radioactive 13C-rich tomato carotenoids PE, PF, and LYC for novel bioavailability and metabolism studies in humans. Specific Aim #2: To compare and define kinetics of absorption and relative bioavailability of tomato-derived carotenoids in men and women using 13C -PE, 13C -PF, and 13C-LYC. We will use 13C-PE, 13C-PF, and 13C-LYC for characterization of uptake kinetics and relative bioavailability of these tomato carotenoids in healthy adult men (n=12) and women (n=12). Specific Aim 3: To identify metabolites of tomato-derived carotenoids in humans over time by employing 13C-PE, 13C-PF, or 13C-LYC. Knowledge and understanding of tomato-derived carotenoid metabolism in humans is speculative at best and essentially nonexistent with regards to both degradation pathways, and production of potentially bioactive compounds. Tracer labeling will allow us to examine the conversion of the orally administered parent compound to metabolites that are characteristic of bioactivation pathways or catabolic/degradation pathways using HPLC-MS/MS. Significance. Only through the development of novel tools to examine the digestion, absorption, bioavailability, tissue distribution, and systemic vs. target tissue metabolism will we be able to understand the mechanisms of action for LYC, PE, and PF in regards to human health. This proposal targets the Program Announcement PAR-08-135 entitled "Exploratory/Developmental Grant for Complementary and Alternative Medicine (CAM) Studies of Humans" of The National Center for Complementary and Alternative Medicine (NCCAM), NCI, the National Institute on Aging (NIA), and the Office of Dietary Supplements (ODS). PUBLIC HEALTH RELEVANCE: This proposal describes studies that characterize new techniques that will help us understand the absorption and metabolism of the major tomato carotenoids. These studies may help us defined the mechanisms of action for lycopene, phytofluene, and phytoene with regards to human health promotion and disease prevention.