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

描述（由申请人提供）：富含类胡萝卜素的番茄和许多番茄衍生产品在过去十年中被广泛销售，用于促进健康和预防疾病。然而，争议比比皆是，在很大程度上是因为它知道太少的生物利用度，代谢和主要的番茄类胡萝卜素番茄红素（LYC），八氢番茄红素（PE）和六氢番茄红素（PF）的作用机制。该资助申请描述了一种新型研究工具的表征和实施，该工具将大大提高我们追踪番茄类胡萝卜素代谢产物吸收的能力。在本申请中描述和测试的新技术是基于生产13 C标记的LYC、PE和PF并在人体中测试它们。这些富含13 C的类胡萝卜素将用于交叉喂养研究，旨在更精确地定义和比较男性和女性如何吸收和代谢番茄类胡萝卜素。具体目标1：利用番茄细胞悬浮培养技术生产13 C-八氢番茄红素（PE）、13 C-六氢番茄红素（PF）和13 C-番茄红素（LYC）。这是第一次，我们将应用番茄细胞悬浮培养来可靠地生产高度纯化的非放射性富含13 C的番茄类胡萝卜素PE、PF和LYC，用于人类的新生物利用度和代谢研究。具体目标#2：使用13 C-PE、13 C-PF和13 C-LYC比较和确定男性和女性中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13 C-PE、13 C-PF和13 C-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。具体目标3：通过使用13 C-PE、13 C-PF或13 C-LYC鉴定番茄衍生类胡萝卜素在人体中随时间的代谢产物。番茄衍生的类胡萝卜素在人类中代谢的知识和理解充其量是推测性的，基本上不存在关于降解途径和潜在生物活性化合物的产生。示踪剂标记将允许我们使用HPLC-MS/MS检查口服给药的母体化合物向生物活化途径或分解代谢/降解途径特征的代谢物的转化。只有通过开发新的工具来检查消化，吸收，生物利用度，组织分布以及全身与靶组织代谢，我们才能了解LYC，PE和PF对人类健康的作用机制。本提案针对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）题为“人类补充和替代医学（CAM）研究的探索/发展补助金”的计划公告PAR-08-135。 公共卫生相关性：该提案描述了新技术的研究特点，这将有助于我们了解主要的番茄类胡萝卜素的吸收和代谢。这些研究有助于我们确定番茄红素、六氢番茄红素和八氢番茄红素在促进人类健康和预防疾病方面的作用机制。

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.