Isolation and Evaluation of Anticarcinogenic Glucosinolates

描述（由申请人提供）：总体目标是开发植物源性硫代葡萄糖苷（GS）作为抗癌和其他慢性疾病的膳食化学保护剂长期供人类使用。GS是一大家族的巯基葡萄糖苷n -羟基硫酸盐，由植物从几种氨基酸合成。它们在十字花科植物（西兰花、卷心菜、花椰菜）中非常丰富，可能是这些植物化学保护特性的主要植物化学贡献。GS是稳定的，生物无活性的异硫氰酸酯的储存形式，是肿瘤发展和生长的有效抑制剂。GS转化为异硫氰酸酯的生物活化（转化）是由植物细胞黑子酶和胃肠道菌群催化的。对这些植物化学物质作用方式的机理认识已经有了很大的进展。目前进展的主要障碍是缺乏足够数量的纯GS用于细胞、动物和人类的评估，以及控制和提高生物利用度。目标1涉及开发更有效的方法，从毫克到公斤逐步大规模地分离和纯化新的和已知的GS。在这笔拨款的支持下，我们的一项重大进展是开发了高效、连续、离心、逆流分配色谱法，这种方法易于扩展，并使生产近1公斤的葡萄糖苷（萝卜硫素的前体）成为可能，并将其提交给NCI RAPID项目进行临床开发。本研究旨在扩展这一新颖高效的分离技术，利用其生物活性来分离更多新的硫代葡萄糖苷。目的2将评价少数最有前途的候选GS的生物活性。活性测试将包括评估细胞系的2期酶诱导、抗氧化和抗炎能力；小鼠皮肤肿瘤的预防；以及保护人体皮肤免受紫外线的侵害。拟议的研究还将测定GS水解物对幽门螺杆菌（胃癌的主要病原体）的抗生素活性。目的3将确定具有高和低GS到异硫氰酸酯转化表型的个体，并试图辨别促成这些特征的因素。具有稳定的低转化表型的队列将接受各种饮食调整，包括益生元和益生菌干预，以增加GS异硫氰酸酯的转化和提高其生物利用度，并增强其保护功效。这一信息将推动我们将GS作为化学保护剂的发展，并可能带来重大的健康益处。公共卫生相关性：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，确定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，以便在动物和人类中进行评估，并制定适当的建议，以实现减少人类疾病风险的目标。

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.