Pharmacokinetics and hepatic uptake of gliquidone affected by Huangqi injection

The root of Astragalus membranaceus also known as Huang Qi in China is a common traditional Chinese herb with extensive pharmacological activities. Huangqi injection (HI), a common preparation of Huang Qi, was wildly co-administered with gliquidone to treat diabetes mellitus and diabetic nephropathy in clinic of China. The aim of the study was to investigate the effect of HI on the pharmacokinetics and hepatic uptake of gliquidone and related mechanism to ensure the safety and efficacy of their usage. Normal rats (n = 5) and streptozotocin (STZ)-induced diabetic rats (n = 5) were administered orally with 120 mg/kg gliquidone alone or in combination with 8 ml/kg HI (i.v.), HI was given intravenously 5 min before that of gliquidone. The plasma concentration of gliquidone was determined by HPLC-fluorescence. In addition, hepatic uptake of gliquidone with or without HI was evaluated in fresh primary rat hepatocytes. Co-administration of HI with gliquidone could significantly increased the bioavailability of gliquidone in normal and STZ-induced diabetic rats (n = 5); the concentration of gliquidone in fresh primary rat hepatocytes was greatly decreased by HI. This study suggested that when HI and gliquidone co-administering to normal and diabetic rats, the pharmacokinetics of gliquidone was greatly changed, and these changes connect with HI inhibiting hepatic uptake of gliquidone, and transportation of gliquidone across liver mucosal membrane inhibited by HI would be the main mechanisms.