RESUMEN
Aim To observe the absorption activity of five components of Polygonum orientale L. Flower ex-tract in Caco-2 cell monolayer. Methods The effects of different concentrations, time, temperature, pH and P-glycoprotein inhibitors on Caco-2 cells were investi-gated by UPLC-MS/MS. Results The absorption of five components of Polygonum orientale L. Flower ex-tract presented a concentration-and time-dependent manner, and the uptake of quercetin was reduced in Caco-2 cells after 90 min. There was a highest intake at 37℃,and the uptake of four components was best in acid environment except for the quercetin at pH 6 , which was best at pH5 . The uptake of quercetin and kaempferol was significantly improved after the addition of P-glycoprotein inhibitors of verapamil. Conclusions The cellular uptake mechanisms of the five compo-nents of Polygonum orientale L. Flower extract is man-inly through passive diffusion. P-glycoprotein is in-volved in the uptake of quercetin and kaempferol.
RESUMEN
P-glycoprotein is one of the members in the superfamily of ATP-binding cassette transporters. It is expressed in many sites in vivo, and is correlated with multidrug resistance. Under physiological conditions, as an efflux pump, P-glycoprotein in the blood-brain barrier can eliminate endogenous substrates and xenobiotics to maintain the balance of internal environment. But at the same time, it also limits the concentration of therapeutic drugs in brain, and thus reduces therapeutic efficacy. P-glycoprotein inhibitors can get drugs across the blood-brain barrier. It is of great importance to improve the blood concentration in brain and bioavailability of central nervous system drugs.