Kaempferol suppression of acute colitis is regulated by the efflux transporters BCRP and MRP2

The bioavailability of most flavonoids is low but effective in vivo; however, the mechanism of the efficacy of flavonoids has not been elucidated. Kaempferol is typical flavonoids., preliminary research indicates that kaempferol has a significant anti-colon cancer and anti-inflammatory effect. We reported previously that the triple recycling pathways significantly increase the local bioavailability of flavonoids and prolong the residence time of flavonoids in the liver and intestines, which is likely the mode by which flavonoids exert local efficacy. Notably, Efflux transporters (ETs), such as Breast cancer resistance protein (BCRP) and Multi drug resistance-associated protein 2 (MRP2), are the main regulatory molecules of the enterohepatic triple recycling pathways. Thus, our current study explored the regulation of kaempferol by BCRP and MRP2 and the role of BCRP and MRP2 in the suppression of Dextran sulfate sodium (DSS)-induced colitis by kaempferol. Herein, four mouse model was constructed, and the Ultra-high-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) method was established to simultaneously quantify kaempferol and its 3 metabolites and investigate the oral pharmacokinetic characteristics and tissue distribution of these compounds. In Bcrp^-/--Mrp2^-/- mice, the movement of kaempferol via the enterohepatic triple recycling was blocked, and the preventative and therapeutic effects of this compound on acute colitis were inhibited. BCRP and MRP2 defects hindered the efflux of kaempferol and its phase II metabolites and increased the plasma levels. Our study revealed that the disposal of kaempferol was regulated by the ETs BCRP and MRP2, and most importantly, the results will help elucidate the mechanism by which kaempferol suppresses the transformation of colitis into colon cancer.