Objective: To develop a sensitive

rapid and effective LC-ESI-MS/MS method for investigating the uptake pathways and mechanisms of matrine in HepG2 cells. Method: Hanbon Megres RP-C18 column (4.6 mm×250 mm

5μm) was adopted. The mobile phase was 10 mmol· L-1ammonium acetate solution (containing 0.1% formic acid)-methanol (35:65). The MS quantification was performed by ESI ion source at the positive ion mode and selective reaction monitoring (SRM). With HepG2 cells as the in vitro model

the effect of temperature

drug concentration and selective inhibitors of polyspecific organic cation transporters on the cellular uptake of matrine were investigated. Result: Matrine in HepG2 cell lysate showed a good linearity within the range of 0.05 and 50.0 nmol· L-1 and the lower limit of quantification was 0.05 nmol· L-1. The uptake at 4 ℃ was significantly lower (P<0.001) than that at 37 ℃. The uptake was significantly decreased(P<0.01) when the concentration was increased from 0.5 μmol· L-1 to 400 μmol· L-1. Furthermore

the uptake of matrine was significantly inhibited (P<0.001) by pyrilamine

verapamil

quinidine and diphenhydramine. Conclusion: A simple

sensitive and rapid LC-ESI-MS/MS method was developed to study the uptake mechanism of matrine in HepG2 cells. The uptake of matrine into HepG2 cells is an active transport mechanism

which is likely due to the organic cation-sensitive transport system.