Comparative pharmacokinetics of five rhubarb anthraquinones in normal and thrombotic focal cerebral ischemia-induced rats.

A comparative oral pharmacokinetic study of five anthraquinones (aloe-emodin, emodin, rhein, chrysophanol and physcion) from the extract of Rheum palmatum L. was performed in normal and thrombotic focal cerebral ischemia (TFCI)-induced rats. The plasma samples were clarified through solid phase extraction prior to simultaneous determination of the anthraquinones with a validated high-performance liquid chromatography-fluorescence system. The results indicated that the Cmax, t(1/2) and AUC(0-t), of aloe-emodin, rhein, emodin and chrysophanol in TFCI-induced rats were nearly double, whereas the CL values were remarkably decreased (p < 0.05) over those of the normal rats. The plasma drug concentration-time data of five anthraquinones to rats fitted a two-compartment open model. The five anthraquinones in rat plasma were absorbed quickly and eliminated slowly in both groups. The obtained results could be helpful for evaluating the impact of the efficacy and safety of the drug in clinical applications.