Enrichment of total flavonoids from Sophora flavescens with polyamide-macroporous resin Influence of producing area and plant age on oxymatrine content in root of Sophora flavescens Study on Tissue Culture and Rapid Propagation of Sophora flavescens Ait. Evaluation on effect of Sophora flavescens roots on metabolic activity of cytochrome P450 2E1 in rats by probe drug method Absorption characteristic of total alkaloids from Sophora flavescens and their monomers in Caco-2 cell model