Three alkaloids in Radix Sophorae flavescentis:metabolic rate in rat liver microsomes and absorption behavior in Caco-2 cells

Objective To investigate the absorption behaviors of three kinds of sophora alkaloids(matrine,oxymatrine and sophocarpine)in Caco-2cells and their metabolic rates in rat liver microsomes.Methods Caco-2cell absorption model was used to analyze the absorption behaviors of three sophora alkaloids and rat liver microsomal model in vitro was used to investigate the metabolic rates of three sophora alkaloids.The contents of three kinds of sophora alkaloids were determined by HPLC-MS and the permeation rates and metabolic rates were calculated.The analytical conditions were as follows:chromatographic column:Agilent Zorbax SB-C18(3.0 mm×100 mm,3.5μm);mobile phase:acetonitrile/water(60∶40,V/V)with isocratic elution;injection volume:5μL;flow rate:0.8mL/min;temperature of column:30℃;and running time:9min.The selective ion monitoring(SIM)in positive ion mode was used in mass spectrometry,with drying gas temperature:350℃;capillary voltage:4 000V;drying gas flow rate:9.0L/min;and fragmentor voltage:90eV.Results In the Caco-2cell absorption model,matrine,oxymatrine and sophocarpine were separated with good linearity(r0.999 5)between0.050 5-10.01μmol/L,with the permeation rates being:matrine 1.251,oxymatrine 0.937 5,and sophocarpine 1.424.In rat liver microsomal model,matrine,oxymatrine and sophocarpine were separated with good linearity(r0.999 8)between0.050 1-1.001μmol/L,with the half-life period being:matrine 4.331 h,oxymatrine 1.084 h,and sophocarpine 2.478 h.The intra-day and inter-day precisions were 5%,the matrix effect was 80%,and the extraction recovery rate was 88%.Conclusion The three kinds of sophora alkaloids can easily pass the Caco-2cell absorption model,with active transport being the main way,and it is difficult for them to be metabolized in rat liver microsomes.