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和降低尿路感染风险之间联系的成分，因为这些化合物在体外可以防止致尿性p菌毛大肠杆菌与尿路上皮细胞的黏附。原花青素是存在于许多植物性药物和营养补充剂中的低聚类黄酮类化合物。然而，蔓越莓原花青素在聚合度、黄烷键性质(A和B型)、黄烷单元羟基化模式和花青素取代方式等方面表现出结构异质性。这种结构上的异质性给生物活性带来了结构上的困难。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，对增加消费的蔓越莓原花青素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函数。因此，鉴于单个寡聚体的多样性很大，我们预计生物活性也会有很大的变化。这项建议的目标是：1.利用在线和离线液相分离-质谱联用法表征标准化NIH-NCCAM蔓越莓产品中原花青素结构的异质性(即分子内键、取代性质和聚合度)，以及2.将原花青素组分的结构特征与细胞培养中的生物活性以及炎症、细菌黏附和氧化的体外模型联系起来。我们将进行三种类型的实验来表征和制备用于生物活性分析的蔓越莓原花青素：1，优化在线和离线层析的实验；2，化学降解研究与产品的质谱学相结合，以快速表征结构；以及3，串联质谱学的裂解研究。然后，我们将用三种方法检测原花青素的生物活性：1.抑制内毒素诱导的巨噬细胞中环氧合酶2的表达；2.体外p-菌毛大肠杆菌与尿路上皮细胞的黏附模型；3.原花青素与低密度脂蛋白的特异性结合和抑制铜诱导的氧化。

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.