Intestinal absorption of Ginseng Radix et Rhizoma extract combined with Acori Tatarinowii Rhizoma in rats

Abstract

To investigate the changes in intestinal absorption of ginsenosides Rg₁, ginsenosides Re and ginsenosides Rd after combined administration of Ginseng Radix et Rhizoma extract and Acori Tatarinowii Rhizoma, in order to confirm whether the combined administration is scientific and rational, and provide experimental basis for pharmaceutical studies of the formula. An in vivo single-pass perfusion method was performed to study the effect of various concentrations of ginsenosides Rg₁, ginsenosides Re, ginsenosides Rd on the intestinal absorption at duodenum, jejunum, ileum and colon. The concentrations of ginsenosides Rg₁, ginsenosides Re, ginsenosides Rd were determined by RP-HPLC.The absorption rate constant (Ka) and the apparent absorption coefficient(Papp) of ginsenosides Rg₁, ginsenosides Re, ginsenosides Rd were calculated.The result showed that ginsenosides Rg₁, ginsenosides Re, ginsenosides Rd had a high absorption rate on upper portion of the small intestine. The drug concentration had not significantly impact on the absorption rate, suggesting that ginsenosides Rg₁, ginsenosides Re, ginsenosides Rd were absorbed via passive diffusion.Volatile oil of Acori Tatarinowii Rhizoma had obvious effect in enhancing intestinal absorption of ginsenosides Rg₁, ginsenosides Re, ginsenosides Rd, indicating that the combined administration of Ginseng extract and Acorus tatarinowii Schott is scientific and rational.