Studies on the intestinal absorption of the alkaloids in the Gancaofuzi decoction in a Caco-2 cell culture system by UPLC–MS/MS analysis

In this study, the Caco-2 cell monolayer model was used to research the characteristic absorption and efflux of five diterpenoid alkaloids in Gancaofuzi decoction. An ultra performance liquid chromatography coupled with tandem mass spectrometry (UPLC–MS/MS) method was developed for the determination of the simulated intestinal transport of five diterpenoid alkaloids with reserpine as internal standard. The use of the apparent permeability coefficient (Papp) and efflux rate (Er) was instituted to evaluate the intestinal absorption of the alkaloids. Transport of the five alkaloids in Caco-2 cell monolayer model was observed to better understand whether the intestinal absorption of alkaloids was influenced by the compatibility of four herbs in Gancaofuzi decoction. The results show that the Papp values of the five diterpenoid alkaloids were all more than 1 × 10−6 cm/s, confirming that the processes of permeability were valid. The flux of the alkaloids was time-dependent, and the intestinal absorption mechanism of the five alkaloids was mainly based on passive transport. The compatibility of Heishunpian, Baizhu, Guizhi and Gancao can reduce the intestinal absorption of alkaloids, especially the most toxic hypaconitine, and the attenuated effect of mixed herbal water extracts was better than that of different herbs’ water extracts combination. The results prove that compatibility of four herbs in Gancaofuzi decoction is rational.

Graphical abstractA UPLC–MS/MS based Caco-2 cell monolayer mode is used to determine whether intestinal absorption of alkaloids is influenced by the compatibility of four herbs in Gancaofuzi decoction.Figure optionsDownload full-size imageDownload as PowerPoint slide