Absorption Characteristics of Nine Phenylpropanoids in Mongolian Medicine Tabson-2 Decoction in Caco-2 Cells

OBJECTIVE To study the absorption characteristics of phenylpropanoids of Mongolian medicine Tabson-2 decoction(TBD) in Caco-2 cells and to preliminarily clarify the oral absorption mechanism of TBD. METHODS Caco-2 cell monolayer model was used to analyze the uptake components of TBD in Caco-2 cells by UPLC-MS/MS, and UPLC-MS/MS analysis method was established to determine the nine best absorbed components of TBD, protocatechuic acid, neochlorogenic acid, chlorogenic acid, cryptogenic acid, 1,5-dicaffeinate quinic acid, isochlorogenic acid C, caffeic acid, dihydrocaffeic acid, chlorogenic acid. The effects of time, concentration and P-glycoprotein inhibitor on the absorption of each component were investigated. RESULTS The overall intake of caffeic acid and dihydrocaffeic acid showed an upward trend in 0-180 min, and did not show saturation. The absorption of 3-hydroxycinnamic acid was constant at about 90 min and tended to saturation. The intakes of cryptochlorogenic acid, 1,5-dicaffeinate, quinic acid, isochlorogenic acid C, neochlorogenic acid, chlorogenic acid and protocatechuic acid first decreased and then increased with time from about 90 min. The addition of P-glycoprotein inhibitor verapamil and cyclosporin A had an effect on the absorption of dihydrocaffeic acid compared with the phenylpropanoid components, indicated that dihydrocaffeic acid was the substrate of P-glycoprotein. CONCLUSION The main phenylpropanoids of TBD enter Caco-2 mainly by passive diffusion, supplemented by active transport, and the absorption process of the other eight components is not affected by the efflux of P-glycoprotein except dihydrocaffeic acid.