Bioactivity and structure for cranberry proanthocyanidins

描述（由申请人提供）：蔓越莓原花青素可能是导致蔓越莓汁消费与尿路感染风险降低之间相关性的成分，因为这些化合物可防止尿路致病性p-菌毛大肠杆菌的粘附。coli对体外培养的尿路上皮细胞的作用。原花青素是存在于许多植物和营养补充剂中的低聚类黄酮。然而，蔓越莓原花色素在聚合度、黄烷间键（A和B型）的性质、黄烷单元的羟基化模式和被花青素取代方面表现出结构异质性。这种结构异质性在结构与生物活性之间产生了困难。由于缺乏可用于蔓越莓产品标准化的结构/生物活性关系的信息，有关蔓越莓原花青素消费量增加的健康益处和风险的生物医学研究受到严重限制。我们的核心假设是蔓越莓原花青素低聚物的生物活性是特定结构的功能。因此，鉴于单个寡聚体的多样性很大，我们预计生物活性会有很大的变化。该提案的目标是：1。使用在线和离线液相色谱分离与质谱联用表征标准化NIH-NCCAM蔓越莓产品中原花青素结构的结构异质性（即分子内键、取代的性质和聚合度），以及2.将原花色素组分的结构特征与细胞培养和体外炎症、细菌粘附和氧化模型中的生物活性相关联。我们将进行3种类型的实验来表征和制备蔓越莓原花青素用于生物活性测定; 1，优化在线和离线色谱的实验，2，化学降解研究与产物质谱联用以快速表征结构，3，使用串联质谱的碎片化研究。然后，我们将使用3种方法测定原花青素级分的生物活性; 1.减弱LPS诱导的巨噬细胞环氧化酶2的表达。用体外粘附模型观察了p-菌毛E.大肠杆菌转化为尿路上皮细胞; 3.原花色素与低密度脂蛋白的特异性结合和铜诱导氧化的抑制。

DESCRIPTION (provided by applicant): Cranberry Proanthocyanidins may be the constituents responsible for the association between consumption of cranberry juice and decreased risks of urinary tract infections because these compounds prevent the adhesion of uropathogenic p-fimbriated E. coli to uroepithelial cells in vitro. Proanthocyanidins are oligomeric flavonoids present in many botanicals and nutritional supplements. However, cranberry proanthocyanidins exhibit structural heterogeneity in the degree of polymerization, nature of interflavan bonds (A and B type), pattern of hydroxylation of flavan units and substitution with anthocyanins. This structural heterogeneity creates difficulty in structure to bioactivity. Biomedical research on the health benefits and risks of increased consumption of cranberry proanthocyanidins is severely limited by lack of information on structure/bioactivity relationships that can be used in standardization of cranberry products. Our core hypothesis is that the bioactivity of cranberry proanthocyanidin oligomers is a function of specific structure. Therefore, given the large diversity of individual oligomers, we would expect large variation in bioactivity. The goals of this proposal are: 1. Characterize structural heterogeneity (i.e. intra-molecular bonds, nature of the substitutions and degree of polymerization) of proanthocyanidin structures in the standardized NIH-NCCAM cranberry products using online and offline liquid chromatographic separations coupled with mass spectrometry, and 2. Relate the structural characteristics of the proanthocyanidin fractions to bioactivity in cell culture and in vitro models of inflammation, bacterial adherence and oxidation. We will carry out 3 types of experiments to characterize and prepare cranberry proanthocyanidins for assays of bioactivity; 1, experiments to optimize online and offline chromatography, 2, chemical degradation studies coupled with mass spectrometry of products to rapidly characterize structure, and 3, fragmentation studies using tandem mass spectrometry. We will then assay proanthocyanidin fractions for bioactivity using 3 methods; 1. Attenuation of LPS induced expression of cycloxygenase 2 in macrophages, 2. In vitro model of adherence of p-fimbriated E. coli to uroepithelial cells, and 3. specific association of proanthocyanidins to low density lipoproteins and inhibition of copper induced oxidation.