Isolation and Evaluation of Anticarcinogenic Glucosinolates

描述(申请人提供)：总体目标是开发植物来源的硫代葡萄糖苷(GS)，供人类长期使用，作为预防癌症和其他慢性疾病的饮食化学保护剂。GS是由植物由几类氨基酸合成的硫代葡萄糖苷N-羟基硫酸酯大家族。它们在十字花科植物(花椰菜、卷心菜、花椰菜)中含量非常丰富，很可能为这些植物的化学保护特性提供主要的植物化学贡献。GS是一种稳定的、生物活性不强的异硫氰酸酯储存形式，对肿瘤的发展和生长具有强大的抑制作用。GS的生物活化(转化)为异硫氰酸酯是由植物细胞芥子酶和胃肠道微生物群催化的。从机理上理解这些植物化学物质的作用方式已经有了很大进展。目前取得进展的主要障碍是缺乏足够数量的纯GS用于在细胞、动物和人类中进行评估，以及控制和提高生物利用度。目标1致力于开发更有效的方法来分离和提纯新的和已知的GS，规模逐渐扩大，从毫克到公斤。在这笔赠款的支持下，我们开发了高效的连续、离心式、逆流分配层析方法，这些方法易于扩展，并使生产近1公斤萝卜素(萝卜硫素的前体)成为可能，并将其提交给NCI快速临床开发计划。这一目标旨在扩展这一新颖而高效的分离技术，以其生物活性为导向分离更多的新硫代葡萄糖苷。目的2将评估少数最有希望的候选GS的生物活性。活性测试将包括评估细胞系中第二阶段酶诱导、抗氧化剂和抗炎的潜力；预防小鼠皮肤肿瘤；以及保护人类皮肤免受紫外线伤害。拟议的研究还将测试GS水解物对幽门螺杆菌(一种导致胃癌的主要病原体)的抗生素活性。目标3将确定具有高和低GS到异硫氰酸酯转化表型的个体，并试图辨别导致这些特征的因素。具有稳定低转化率表型的队列将接受各种饮食修改，包括益生菌和益生菌干预，以提高转化率和改善GS异硫氰酸酯的生物利用度，并增强其保护效果。这些信息将促进GS作为化学保护剂的发展，并可能带来重大的健康益处。与公共健康相关：该项目的目标是通过增强我们的细胞对氧化剂、破坏DNA的化学物质、炎症和辐射的防御能力，识别阻止癌症和其他慢性疾病发展的植物成分。我们将分离出足够数量的这些成分，用于在动物和人类身上进行评估，并制定适当的建议，以实现人类疾病风险的降低。

DESCRIPTION (provided by applicant): The overall goals are to develop plant-derived glucosinolates (GS) for long-term human use as dietary chemoprotectors against cancer and other chronic diseases. GS are a large family of thioglucoside N-hydroxysulfates synthesized by plants from several classes of amino acids. They are very abundant in crucifers (broccoli, cabbage, cauliflower) and are likely to provide the main phytochemical contribution to the chemoprotective properties of these plants. GS are the stable, biologically inactive storage forms of isothiocyanates which are potent inhibitors of tumor development and growth. Bioactivation (conversion) of GS to isothiocyanates is catalyzed by plant cell myrosinase and by the gastrointestinal microflora. Mechanistic understanding of the mode of action of these phytochemicals has advanced greatly. The principal obstacles to progress are now lack of adequate quantities of pure GS for evaluation in cells, animals, and humans, and to control and improve bioavailability. Aim 1 is concerned with developing more efficient methods for isolating and purifying new and already known GS on a progressively larger scale from milligrams to kilograms. With support of this grant, a major advance has been our development of highly efficient continuous, centrifugal, counter-current partition chromatography methods which are easily scalable, and have made possible the production of almost 1 kg of glucoraphanin (the precursor of sulforaphane) and its submission to the NCI RAPID program for clinical development. This aim seeks to expand this novel and highly efficient separation technology for isolation of additional new glucosinolates guided by their biological activities. Aim 2 will evaluate the biological activities of a small number of the most promising candidate GS. Activity testing will include evaluating phase 2 enzyme induction, antioxidant, and anti-inflammatory potencies in cell lines; prevention of mouse skin tumors; and protection of human skin against UV. Proposed studies will also assay the antibiotic activity of GS hydrolysates against Helicobacter pylori (a major causative agent of gastric cancer). Aim 3 will identify individuals with high and low GS to isothiocyanate conversion phenotypes and attempt to discern the factors contributing to these characteristics. Cohorts with stable low conversion phenotypes will be subjected to a variety of dietary modifications, including prebiotic and probiotic interventions, in order to increase conversions and improve the bioavailability of isothiocyanates from GS, and enhance their protective efficacy. This information will advance our development of GS as chemoprotectors and could lead to major health benefits. PUBLIC HEALTH RELEVANCE: The goals of this project are to identify plant components that block the development of cancer and other chronic diseases by boosting our cellular defenses against oxidants, DNA-damaging chemicals, inflammation and radiation. We will isolate these components in adequate quantities for evaluation in animals and humans, and formulate appropriate recommendations to achieve disease risk reduction in humans.