Rios Laurent Y, Bennett Richard N, Lazarus Sheryl A, Rémésy Christian, Scalbert Augustin, Williamson Gary
Institute of Food Research, Norwich Research Park, Norwich, United Kingdom.
Am J Clin Nutr. 2002 Nov;76(5):1106-10. doi: 10.1093/ajcn/76.5.1106.
Polyphenolic procyanidins are abundant flavonoid polymers in Western diets. In vitro biological activity has been reported for these compounds, but activity in vivo depends on the amount and chemical nature of the flavonoids reaching the gastrointestinal tract. Degradation of procyanidins under simulated gastric conditions at pH 2.0 has been reported in vitro.
The objective was to examine whether depolymerization of procyanidins occurs in the stomach of human subjects in vivo.
After an overnight fast, 6 healthy subjects (3 men and 3 women) consumed 500 mL of a cocoa beverage containing 733 mg procyanidin polymers and 351 mg structurally related flavanol monomers. With the use of a nasogastric tube, stomach contents were collected every 10 min after beverage ingestion until the stomach was emptied. Flavanols and procyanidins (up to pentamers) were quantified by normal and reversed-phase HPLC.
In all subjects, gastric transit lasted approximately 50-60 min. No change in the HPLC profile of procyanidins was observed during this period, showing that procyanidins were remarkably stable in the stomach environment.
The results suggest that most ingested procyanidins reach the small intestine intact and are available for absorption or metabolism.
多酚原花青素是西方饮食中丰富的类黄酮聚合物。已报道了这些化合物的体外生物活性，但体内活性取决于到达胃肠道的类黄酮的量和化学性质。体外已报道原花青素在pH 2.0的模拟胃条件下会降解。
目的是研究原花青素在人体受试者胃内是否会发生解聚。
经过一夜禁食后，6名健康受试者（3名男性和3名女性）饮用了500 mL含有733 mg原花青素聚合物和351 mg结构相关黄烷醇单体的可可饮料。使用鼻胃管，在饮用饮料后每隔10分钟收集胃内容物，直至胃排空。通过正相和反相高效液相色谱法定量黄烷醇和原花青素（直至五聚体）。
在所有受试者中，胃排空持续约50 - 60分钟。在此期间未观察到原花青素的高效液相色谱图有变化，表明原花青素在胃环境中非常稳定。
结果表明，大多数摄入的原花青素完整地到达小肠，可供吸收或代谢。
