Pharmacokinetics and brain distribution of ginsenosides after administration of Sailuotong

Abstract

Sailuotong (SLT) is a compound preparation composed of ginseng, ginkgo and saffron for the treatment of vascular dementia In order to identify its material foundation and provide evidence for therapeutic regimen, the pharmacokinetics and brain distribution of ginsenosides were investigated after intragastric administration of SLT. An LC-MS/MS method was developed for the determination of 7 ginsenosides in rat plasma simultaneously. Statistical analysis of obtained data demonstrated that the method has achieved the desired linearity, precision, accuracy and sensitivity. After administration of SLT at 60 mg x kg(-1) dose, 7 ginsengosides were all absorbed into systematic circulation. The quantitative and statistical analysis of gensenosides in plasma showed that protopanaxdiol saponins exhibited higher concentration and longer half life than protopanaxatriol saponins. The mean value of half life of ginsenosides Rg1, Re, Rb1, Rb2/b3, Rc and Rd were 15.26, 2.46, 18.41, 27.70, 21.86 and 61.58 h respectively. The peak concentration of them were 7.15, 2.83, 55.32, 30.22, 21.42, 8.81 microg x L(-1) respectively. The determination of brain distribution at different time after dosing revealed ginsenosides entered into brain promptly but the concentration declined along with time rapidly. The ginsenosides with higher concentration in brain were Rg1, Re, Rb1 and Rc. These findings demonstrated ginsenosides could be absorbed in blood and penetrated into brain rapidly. Some ginsenosides, especially Rg1 and Re, might be the main components directly effecting neurocyte in brain taking advantage of their better brain distribution. While ginsenosides of mostly protopanaxdiol saponins might protect brain mainly depending on peripheral efficacy in virtue of their long residence in blood, by which higher concentration could be reached after multiple dosing.