Pharmacokinetic Characterizations of Ginsenoside Ocotillol, RT5 and F11, the Promising Agents for Alzheimer’s Disease from American Ginseng, in Rats and Beagle Dogs

Abstract

Background: Ocotillol, RT₅ and F₁₁, the main active components of ocotillol type ginsenosides, have attracted a lot of attention due to their beneficial effects on neurodegenerative disease models of Alzheimer’s disease. Pharmacokinetic (PK) is a bridge linking the herbal medicines and their pharmacological responses. However, few data are available regarding PK behaviors of ocotillol type ginsenosides. Methods: The liquid chromatography-tandem mass spectrometry methods were developed and validated to calculate the concentrations of 3 ginsenosides in different biological matrices. Rat and beagle dog plasma samples were deproteinized with methanol and separated on Shim-pack GIST C₁₈ column. All of the analytes were detected in positive ion mode using multiple reaction monitoring. Results: The methods showed good linearity (r > 0.996) in the established concentration range. All validated data, such as specificity, intra- and inter-day precision, accuracy, extraction recovery, matrix effect, and stability were within required limits. The values of C_max and AUC_(0–t) indicated ocotillol type ginsenosides had low systemic exposure and poor absorption into blood. T_1/2 and MRT_(0–t) demonstrated the elimination process of ocotillol type ginsenosides might be slow. Double peaks were observed in the mean plasma concentration versus time profiles of ocotillol, RT₅, and F₁₁ after oral intake. Conclusions: This was the first PK investigation of the ocotillol type ginsenosides in rats and beagle dogs. The results we found here were helpful to our understanding of the absorption mechanism of ocotillol type ginsenosides and provided the scientific basis for further pre-clinical research.