Cognitive Effects of Grape Seed Extract-Brain Protein Targets

描述（由申请人提供）：我们最近发现，幼龄（1个月）卵巢切除的自发性高血压大鼠（OVX-SHR）在饮食中摄入低剂量（0.5%）的葡萄籽提取物（GSE）后，认知能力增强，表明GSE对哺乳动物大脑有益。先前的研究表明，在正常的年轻成年雌性大鼠中，高（5%）但无毒的膳食剂量的GSE会改变大脑蛋白质；这些蛋白质包括许多先前被证明在阿尔茨海默病患者的大脑和痴呆症的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部分变化方向是那些被认为是有益的。最近，我们发现，在痴呆转基因小鼠模型中，摄入GSE导致脑蛋白氧化减少，提示GSE在啮齿动物大脑中的抗氧化作用，并且与我们和其他人的数据一致，表明GSE在其他慢性疾病模型中具有健康益处。虽然对GSE和类似制剂进行了大量的实验，但尚未对GSE的有效剂量范围和最佳摄入时间进行系统的分析。这些实验参数，以及在实验过程中对制剂组成变异性或稳定性的理解，是严格理解膳食给药生物活性化合物的作用和作用机制所必需的。该研究将利用OVX- SHR（一种绝经后高血压加速模型），并验证低剂量葡萄籽提取物对卵巢切除术引起的老年认知障碍的保护作用。OVX- shr对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验较短的GSE给药时间是否对行为有益。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脑中雌激素剥夺引起的蛋白质差异，以及哪些蛋白质差异在保护剂量下被GSE减弱。这将是了解雌激素丧失对认知功能的影响，以及GSE等多酚物质如何抵消雌激素丧失的初步步骤。在研究过程中，将采用基于hplc -质谱的方法监测GSE制剂和添加GSE的膳食的组成和稳定性。我们的目标是确定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GSE和其他植物性膳食补充剂防止衰老和更年期相关认知衰退的机制奠定基础。

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.