Evaluation Of The Transport And First-pass Glucuronidation Of 6, 8-ditrifluoromethyl-7-acetoxychrysin In Caco-2 Monolayer Model

Objective: To illuminate from pharmacokinetics why 6, 8-ditrifluoromethyl-7-acetoxychrysin (dFMAChR) performing stronger biological effect than chrysin (ChR) and in order to find a new chemical entity as having good pharmacodynamics as well good pharmacokinetics, we compared the character of transport and glucuronidation of dFMAChR to ChR in Caco-2 monolayer model.Methods: We established precise, sensitive and having good reproducibility determination methods of ChR and dFMAChR by HPLC. MTT assay was used to determine the cell toxicity of ChR and dFMAChR to Caco-2 cells. Cultured Caco-2 cells in vitro and established Caco-2 monolayer model in Transwell system. Evaluated the optimization transportation mediator pH of dFMAChR and ChR. Evaluated the relationship of time and concentration with transportation of dFMAChR and ChR by examining the compounds amount using HPLC and calculating apparent permeability coefficient (Papp). Evaluated the relationship of time with glucuronic conjunction formation of dFMAChR and ChR by HPLC examination.Results: 50μmol/L ChR and dFMAChR in pH 7.4, 37℃PBS for 24h, the saturated solubility of them were 4.28±0.56μmol/L, 2.05±0.44μmol/L, respectively. The stability of ChR is low with the unchange decreasing as solution pH enhancement, but the dFMAChR was more stable than ChR. ChR and dFMAChR under certain concentration had little toxicity to Caco-2 cells, even though 100μmol/L by MTT assay. The Caco-2 cells were cultured in Transwell for 21 days, we established cell monolayer model successfully. dFMAChR and ChR accumulation transportation amount reduced along with the pH of mediator increasing. The transport amount of dFMAChR and ChR dependent on time and concentration, nearly assuming the linear relation. The transportation of them had no direction,from Apiral to Basolateral occupied the superiority. More important, the transportation amount of dFMAChR increase significantly compare to ChR in Caco-2 monolayer. Glucuronic conjunction of dFMAChR and ChR increased as time lasting, while the glucuronidation formation rate of dFMAChR descended remarkly.Conclusion: Both dFMAChR and ChR transport through passive diffusion. After modification by introducing acetoxy and tri-fluoromethy of chrysin, the chemical and metabolic stability of its derivate dFMAChR increased, with the transport rate raising and glucuronidation rate decreasing significantly.