Effects of Different Dahuang Huanglian Xiexin Decoction Formulations on the Pharmacokinetics of Baicalin and Wogonoside in Rats
大黄黄连泻心汤不同配伍下黄芩苷和汉黄芩苷在大鼠体内的药动学比较研究

This study was aimed to examine effects of Dahuang (DH) and Huanglian (HL) on the pharmacokinetics of baicalin and wogonoside, which are major bioactive chemicals of Huangqin (HQ), in rats after administering HQ alone and HQ in combination with DH and/or HL. Rats were administered a single oral dosage of HQ or HQ in combination with DH and/or HL. Blood samples were taken at different time points post-dosing and analyzed for baicalin and wogonoside using HPLC-UV. The plasma concentration-time curves were compared and analyzed. The results showed that the absorption of baicalin and wogonoside were rapid and can be described by two characteristic absorption peaks in HQ group. After the administration of DH-HQ to rat, the secondary absorption peaks of both baicalin and wogonoside plasma concentration-time profiles disappeared completely with the decrease of Cmax1 and AUC, as well as a shorten action time. The total exposure level of flavones in plasma was not changed after combining with HL, while Cmax2 of wogonoside increased remarkably. In DH-HL-HQ combination, Cmax1 of baicalin and wogonoside as well as CL/F and AUC of baicalin were reduced significantly. It was concluded that the absorption of baicalin and wogonoside are decreased by DH and increased by HL. HL may weaken the effect of DH that inhibits the absorption and increases the clearance as well as enlarges the distribution of baicalin and wogonoside.