Pharmacokinetics of ginsenosides Rg₁ and its metabolites in rats

To study the pharmacokinetics of ginsenosides Rg₁ and its metabolites after iv and oral administration in Wistar rats, the LC-MS/MS method was selected to determine ginsenosides Rg₁ and its metabolites  in plasma and their pharmacokinetic parameters were calculated.  After oral administration of ginsenosides Rg₁ to rats, ginsenosides Rg₁, Rh₁, F₁ and protopanaxatriol (Ppt) could be detected in plasma.  Their T_max were  0.92, 3.64, 5.17, and 7.30 h, respectively; MRT were 2.68, 5.06, 6.65, and 5.33 h, respectively; AUC_0−t were    2 363.5, 4 185.5, 3 774.3, and 396.2 ng·mL⁻¹·h, respectively.  After iv administration of ginsenosides Rg₁ to rats, ginsenosides Rg₁, Rh₁ and F₁ could be detected in plasma.  Their T_1/2βs were 3.12, 5.87, and 6.87 h, respectively; MRTs were 1.92, 5.99, and 7.13 h, respectively; AUC_0−ts were 1 454.7, 597.5, and 805.6 ng·mL⁻¹·h, respectively.  So, it can be concluded that after oral administration, the amounts of metabolites were higher than the prototype in vivo, and the distribution and elimination of the metabolites were relatively slow.  After iv administration, the amount of prototype were higher than that of the metabolites in vivo, and the distribution and elimination of the metabolites were relatively slow.