Cognitive Effects of Grape Seed Extract-Brain Protein Targets

描述（由申请人提供）：我们最近表明，在饮食中喂食低剂量（0.5%）葡萄籽提取物（GSE）的年轻（1个月大）卵巢切除自发性高血压大鼠（OVX-SHR）表现出增强的认知能力，提示GSE在哺乳动物大脑中的有益作用。先前的研究表明，饮食中给予高浓度（5%）但无毒的GSE改变了正常年轻成年雌性大鼠的脑蛋白;这些蛋白质包括许多先前显示在阿尔茨海默病患者和痴呆症转基因模型中受到影响的蛋白质。受影响的大脑蛋白质的大多数变化方向被认为是有益的。最近，我们发现GSE摄入导致痴呆症转基因小鼠模型中脑蛋白氧化的减少，这表明GSE在啮齿动物脑中的抗氧化作用，并且与我们和其他人的数据一致，这些数据显示GSE在其他慢性疾病模型中的健康益处。虽然已经对GSE和类似制剂进行了大量实验，但尚未对GSE的有效剂量范围以及GSE摄入的最佳时机进行系统分析。这些实验参数以及对实验过程中制剂的组成变化性或稳定性的理解是严格理解饮食给药的生物活性化合物的作用和作用机制所必需的。拟议的研究将利用OVX-SHR，一种加速绝经后高血压的模型，并测试低剂量葡萄籽提取物预防卵巢切除术诱导的晚年认知障碍的假设。OVX-SHR对从OVX时开始给予GSE的系统剂量反应分析将确定GSE的最低有效剂量。在此剂量下的后续实验将检查较短时间的GSE给药是否具有行为益处。一旦确定了GSE的有益剂量，我们将通过2D凝胶蛋白质组学方法确定SHR脑中雌激素剥夺诱导的蛋白质差异，以及其中哪些蛋白质在保护剂量下被GSE减弱。这些将是理解雌激素丧失对认知功能的后果的初步步骤，以及多酚物质如GSE如何对抗雌激素剥夺。在研究过程中，将通过基于HPLC-质谱的方法监测GSE制剂和添加GSE的饲料的组成和稳定性。我们的目标是定义在人类慢性疾病模型中研究GSE和相关补充剂的实验参数，这将为严格研究这种和其他基于植物的膳食补充剂保护免受衰老和更年期相关认知下降的机制奠定基础。 公共卫生相关性：我们将在大鼠中确定葡萄籽提取物（GSE）的最低有效剂量，该最低有效剂量可防止由切除卵巢（卵巢切除术或OVX）引起的雌激素剥夺引起的晚年认知能力下降。生物化学实验将鉴定由OVX诱导的脑蛋白质变化，并确定在最低剂量的GSE下仍保护免受OVX诱导的认知损害的GSE阻止了哪些变化，从而开始鉴定作为OVX诱导的认知下降机制的蛋白质变化。由于蛋白质氧化被认为与年龄相关的脑功能障碍有关，我们还将研究OVX后发生的蛋白质氧化，以及保护剂量的GSE所预防的蛋白质氧化。这些研究将为GSE和相关膳食补充剂的未来研究确定实验参数，以评估人类慢性疾病模型的作用机制。

DESCRIPTION (provided by applicant): We recently showed that young (1 month old) ovariectomized spontaneously hypertensive rats (OVX-SHR) fed a low dose (0.5%) of grape seed extract (GSE) in the diet exhibited enhanced cognitive abilities, suggestive of beneficial actions of the GSE in mammalian brain. Previous studies had shown that dietary administration of the GSE at a high (5%) but nontoxic concentration altered brain proteins in normal young adult female rats; these proteins included many previously shown to be affected in the brains of Alzheimer's disease patients and in transgenic models of dementia. The majority of the directions of change for the affected brain proteins were in those considered beneficial. More recently, we showed that GSE intake resulted in a reduction in brain protein oxidations in a transgenic mouse model of dementia, suggestive of anti-oxidant actions of GSE in rodent brain, and consistent with our and others' data showing health benefits of GSE in other models of chronic disease. While much experimentation has been carried out with GSE and similar preparations, systematic analysis of the effective dose range of GSE, and the optimal timing of GSE intake, have not been done. Such experimental parameters, as well as an understanding of compositional variability or stability of the preparations during the course of the experiment, are required for rigorous understanding of the actions and mechanisms of action of dietarily administered bioactive compounds. The proposed studies will utilize OVX- SHR, a model of accelerated postmenopausal hypertension, and test the hypothesis that low doses of grape seed extract protect against ovariectomy-induced late-life cognitive impairment. A systematic dose response analysis of OVX-SHR to GSE administered from the time of OVX will determine the lowest effective dose of GSE. Follow up experiments at this dose will then examine whether shorter times of administration of GSE can have behavioral benefit. Once a beneficial dose of GSE is identified, we will identify by 2D gel proteomics approaches protein differences induced by estrogen-deprivation in the SHR brain, and which of these are attenuated by GSE at the protective dose. These will be initial steps in understanding the consequences of the loss of estrogen in cognitive function, and how polyphenolic substances such as GSE counteract estrogen- deprivation. GSE preparations and diet-supplemented with GSE will be monitored by HPLC-mass spectrometry-based methods for composition and stability during the course of the study. Our objective is to define experimental parameters for the study of GSE and related supplements in models of human chronic disease that will lay a foundation for rigorous studies on the mechanisms by which this and other botanically- based dietary supplements protect from aging- and menopause-related cognitive decline. PUBLIC HEALTH RELEVANCE: We will determine in rats the lowest effective dose of grape seed extract (GSE) that protects against late life cognitive decline induced by estrogen deprivation, caused by removal of the ovaries (ovariectomy or OVX). Biochemical experiments will identify the brain protein changes induced by the OVX, and determine which of these are prevented by the GSE at the lowest dose of GSE that still protects against the OVX-induced cognitive impairment, to begin to identify protein changes that are the mechanism of OVX-induced cognitive decline. Because protein oxidations are thought to be involved in age-related brain dysfunction, we will also study what protein oxidations occur following OVX, and which are prevented by protective doses of GSE. The studies will define experimental parameters for future studies with GSE and related dietary supplements to assess mechanisms of action in models of human chronic disease.