Studies on Absorption and Tansport of Limoninoids from Fructus Evodiae in Caco-2 Cell Monolayer Model

Objective To study the intestinal absorption and transepithelial transport of three limoninoids: evodol (EVO), limonin (LIM), and shihulimonin A (SHIA), isolated from Fructus Evodiae [the unripe fruit of Evodia rutaecarpa and Evodia rutaecarpa var. bodinieri] in the human intestine. Methods The in vitro cultured human colon carcinoma cell line, Caco-2 cell monolayer model, was applied to studying the absorption and transepithelial transport of the three limoninoids from apical (AP) to basolateral (BL) side and from BL to AP side. The three limoninoids were measured by reversed-phase high performance liquid chromatography coupled with ultraviolet absorption detector. Transport parameters and apparent permeability coefficients (Papp) were then calculated and compared with those of Propranolol as a control substance of high permeability and Atenolol as a control substance of poor permeability. Results The Papp value of EVO and LIM from AP to BL side for absorption and transport were 1.78 × 10-5 cm/s and 1.16 × 10-5 cm/s, respectively, which was comparable to that of Propranolol with Papp 2.18 × 10-5 cm/s. Conclusion The absorption and transport of both EVO and LIM are main passive diffusion as the dominating process in Caco-2 cell monolayer model, and they were estimated to be high absorbed compounds. SHIA in Caco-2 cell monolayer model may be involved in metabolism in the transport processes.

In vitro screening of reversible and time-dependent inhibition on CYP3A by TM208 and TM209 in rat liver microsomes

TM208 and TM209,dithiocarbamate derivatives with potential anti-cancer effects,were evaluated in reversible and time-dependent cytochrome P450(CYP)3A inhibition assays in rat liver microsomes using testosterone as probe substrate.Both compounds were found to be weak reversible inhibitors and moderate mechanism-based inhibitors of rat CYP3A.For reversible inhibition on rat CYP3A,the Ki values of competitive inhibition model were 12.10±1.75 and 13.94±1.31 μM,respectively.For time-dependent inhibition,the inactivation constants(K_(l))were 31.93±12.64 and 32.91±15.58 μM,respectively,and the maximum inactivation rates(kinact)were 0.0349770.0069 and 0.0725970.0172 min^(-1) respectively.These findings would provide useful in vitro information for future in vivo DDI studies on TM208 or TM209。

UFLC-DAD-ESI-IT-TOFMSn Analysis on Biotransformation of Tongmai Formula Incubated with Human Intestinal Bacteria

Objective To investigate the biotransformation of Tongmai formula（TMF） in incubated system of human intestinal flora（HIF）. Methods The technique of ultra fast liquid chromatography with diode array detector and coupled with electrospray ionization ion trap time-of-flight multistage mass spectrometry（UFLC-DAD-ESIIT-TOFMSn） was adopted to determine the products of TMF biotransformed by HIF. Results Totally 66 constituents were detected and identified according to the accurate mass measurements（〈 5 ppm） and effective MSn fragment ions. Meanwhile, the potential biotransformational pathways of compounds in TMF transformed by HIF were firstly proposed. Desugarization, hydroxylation, and methylation were the major reactions in the biotransformation mechanism of TMF by HIF. Conclusion This study will be helpful to clarify the material basis of pharmacological activities from TMF in vivo.