Biodistribution and pharmacokinetic profile of berberine and its metabolites in hepatocytes

•Berberine and its metabolites were detected in HepG2 cells by using a reliable LC/MSn-IT-TOF method.•The pharmacokinetic characterization of berberine and its metabolites in HepG2 cells were performed by LC-MS/MS analysis.•Glucuronic-conjugated demethyleneberberine could partially metabolize to sulfate conjugates and demethyleneberberine.•Kaempferol could effectively inhibit the sulfurization metabolic reaction of demethyleneberberine in HepG2 cells.