Isolation and Evaluation of Anticarcinogenic Glucosinolates

描述（由申请人提供）：总体目标是开发植物来源的芥子油苷（GS），供人类长期使用，作为膳食化学保护剂，对抗癌症和其他慢性疾病。GS是由植物从几类氨基酸合成的硫代葡萄糖苷N-羟基硫酸盐的大家族。他们是非常丰富的十字花科植物（花椰菜，卷心菜，花椰菜），并可能提供这些植物的化学保护特性的主要植物化学贡献。GS是异硫氰酸酯的稳定的、无生物活性的储存形式，异硫氰酸酯是肿瘤发展和生长的有效抑制剂。GS向异硫氰酸酯的生物活化（转化）由植物细胞黑芥子酶和胃肠道微生物菌群催化。这些植物化学物质的作用模式的机制的理解有很大的进步。目前，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涉及开发更有效的方法，用于在从毫克到千克的逐渐更大的规模上分离和纯化新的和已知的GS。在该资助的支持下，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，该方法易于扩展，并使近1公斤萝卜硫素（萝卜硫素的前体）的生产成为可能，并将其提交给NCI RAPID计划用于临床开发。这一目标旨在扩展这种新型高效分离技术，以分离出更多的新硫代葡萄糖苷，并以其生物活性为指导。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的第2阶段酶诱导、抗氧化和抗炎效力;预防小鼠皮肤肿瘤;以及保护人类皮肤免受紫外线侵害。拟议的研究还将测定GS水解物对幽门螺杆菌（胃癌的主要致病菌）的抗生素活性。目的3将确定具有高和低GS向异硫氰酸盐转化表型的个体，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经历各种饮食改变，包括益生元和益生菌干预，以增加转化和改善GS中异硫氰酸酯的生物利用度，并增强其保护功效。这些信息将促进我们开发GS作为化学保护剂，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对氧化剂，DNA损伤化学物质，炎症和辐射的细胞防御来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，用于动物和人类的评估，并制定适当的建议，以降低人类的疾病风险。

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.