ABSTRACT
To study the absorption characteristics of Xinshao extracts in Caco-2 cells. In this paper, human colon adenocarcinoma cell line Caco-2 cell model was established, and UPLC-MS method was applied to determinate the contents of five components of Xinshao extracts(albiflorin, gallic acid, caffeic acid, scutellarin and apigenin-7-O-glucronide) in cell lysates. This model was also used to study the effect of different drug concentrations, pH, time and temperature on the absorption of five components, investigate the transport of the five components of Xinshao extracts under the conditions with or without P-glycoprotein inhibitors, and predict the absorption mechanism of these five components in Caco-2 cells. The experimental results showed that the absorption of five components of Xinshao extracts in Caco-2 cells was time-dependent at 37 ℃, and concentration-dependent in the range of 0.5-12.5 g•L⁻¹, with a passive diffusion mechanism. At the pH of 4-7.4, the absorption of caffeic acid, scutellarin and apigenin-7-O-glucronide was significantly declined with the increase of pH(P<0.05). At the temperature of 4 to 37 ℃, the absorption of caffeic acid was declined with the increase of temperature, while the absorption of other four components was increased with the increase of temperature. Compared with the control group, caffeic acid and scutellarin cell absorption was significantly higher(P<0.05) after treatment with P-glycoprotein inhibitors(verapamil and cyclosporine A). The results indicated that, the absorption mechanism of five components in Xinshao extracts may be of passive diffusion, and the caffeic acid and scutellarin may be the substrates of P-glycoprotein.