表没食子儿茶素没食子酸酯对米饭中污染物镉的肠吸收转运的影响

Effects of(-)-Epigallocatechin-3-gallate on Intestinal Absorption and Transport of the Pollutant Cadmium in Cooked Rice

近年随着水体和土壤污染的加剧,我国大米镉污染的形势也愈发严峻。人体的镉暴露途径主要是膳食,镉消化后主要在机体内的小肠部位吸收。本研究首先测定大米及蒸煮米饭中污染物镉的含量,利用已建立的体外口腔-胃-肠消化模型来测定米饭消化后镉的生物可给性,最后采用Caco-2/HT-29细胞共培养肠吸收模型来研究表没食子儿茶素没食子酸酯((-)-epigallocatechin-3-gallate,EGCG)干预对米饭中镉吸收转运率的影响。结果表明:胃消化2 h的生物可给性为(73.58±1.92)%,肠消化7 h的生物可给性为(36.29±1.25)%;EGCG干预后米饭消化液中镉的吸收转运率显著降低,与对照组相比,21.82μmol/L和43.64μmol/L EGCG使镉的吸收转运率分别降低了5.56%和13.89%,该研究为镉暴露地区人群的膳食策略提供了新的思路。

In recent years,with the aggravation of water and soil pollution,the situation of cadmium pollution in rice has got more and more serious in China.The primary route of cadmium exposure in humans is dietary digestion,and it is absorbed in the small intestine.In this study,the cadmium contents in contaminated raw and cooked rice were analyzed,and then the bioaccessibility of cadmium after digestion was determined by using an in vitro oral-gastric-intestinal digestion model.Finally,a Caco-2/HT-29 cell co-culture model was used to evaluate the effect of(-)-epigallocatechin-3-gallate(EGCG)on the absorption and transport rates of cadmium in the digestive fluid of cooked rice.The results indicated that cadmium bioaccessibility in the gastric phase was(73.58±1.92)%after simulated digestion for 2 h,and(36.29±1.25)%in the small intestinal phase after simulated digestion for 7 h.Moreover,EGCG significantly reduced the absorption and transport rates of cadmium in the digestive fluid of cooked rice,at 21.82 and 43.64μmol/L by 5.56%and 13.89%compared with the control group,respectively.This study may provide a new insight into dietary intervention for in general populations in cadmium exposure regions.