目的 探讨槲皮素在人小肠吸收模型 Caco-2 单层细胞上的吸收特征以及基于葡萄糖肠道吸收中的主动转运蛋白 -- Na+ 依赖性葡萄糖转运蛋白 1 和易化扩散转运蛋白 -- 葡萄糖易化扩散转运蛋白 2 的跨膜吸收机制。方法 采用 Caco-2 单层 细胞模型，利用 Na+ 依赖性葡萄糖转运蛋白 1 和葡萄糖易化扩散转运蛋白 2 特效抑制剂根皮苷和根皮素，以丁螺环酮为内标、 LC-MS 法测定孵育 30~150 分钟内各时间节点 Caco-2 细胞透过面槲皮素浓度，研究 Na+ 依赖性葡萄糖转运蛋白 1 和葡萄糖 易化扩散转运蛋白 2 在槲皮素肠道吸收中的作用，探讨槲皮素的肠道吸收机制。结果 在孵育 30~150 分钟各时间点，均在 透过面检测到相应的槲皮素原形；透过面的槲皮素含量在 150 分钟孵育时间内呈现先升后降的趋势特征，120 分钟达峰 , 随 后下降，没有观察到平台期；葡萄糖和根皮苷对槲素的跨膜转运均表现出了明显的抑制作用，跟皮苷的抑制作用随孵育时 间逐渐减弱，而根皮素却明显上调了槲皮素的透过水平（P ＜ 0.05），原因不明。结论 槲皮素可以以完整分子的形式透过 Caco-2 细胞单层， Na+ 依赖性葡萄糖转运蛋白 1 和葡萄糖易化扩散转运蛋白 2 可能同时参与槲皮素的跨膜转运，Na+ 依赖 性葡萄糖转运蛋白 1 在槲皮素的跨膜转运占据重要的位置，而葡萄糖易化扩散转运蛋白 2 的作用有待进一步研究。

Objective To explore the transmembrane absorption mechanism of quercetin based on sodium-dependent glucose transporter 1 (SGLT1) and glucose transporter 2 (GLUT2) in human intestinal epithelial cells (Caco-2) model. Methods Quercetin and buspirone (internal standard) were assessed by using the liquid chromatography-mass spectrometry (LC/MS) method. Transmembrane transport of quercetin was studied in a Caco-2 cell monolayer model, and the roles of SGLT1 and GLUT2 in this process were studied by using phloridzin (a potent inhibitor of SGLT1) and phloretin (a potent inhibitor of GLUT2). Quercetin was detected in receiver solution of the Caco-2 cell monolayer within 30~150 min. Results During 30~150min’s incubation, quercetin aglycon was detected among every group on the receiver side of transmembrane transport. The amount of quercetin in receiver solution increased at first and peaked at 120 min, and then decreased. Phloridzin exerted an obvious inhibitory effect on the transmembrane transport of quercetin, and meanwhile the phloretin significantly raised the amount of quercetin in the receiver side. Conclusions Quercetin was transported in a complete molecular form across the Caco-2 cell monolayer, and SGLT1 and GLUT2 might both be involved in its transmembrane transport simultaneously, but further research is needed to confirm the role of GLUT2 in the transmembrane transport of quercetin.