A rapid, sensitive, and selective liquid chromatography–mass spectrometry method for simultaneous quantification of astragaloside IV and cycloastragenol in mouse plasma and its application to a pharmacokinetic study

Abstract

Astragaloside IV is the primary active ingredient of Astragalus membranaceus (Fisch.) Bunge with multiple pharmacological effects and a promising therapeutic agent for a number of diseases such as diabetic nephropathy and heart disease. To study the pharmacokinetics of astragaloside IV in mice, a rapid, sensitive, and selective liquid chromatography–mass spectrometry method was developed for the simultaneous quantification of astragaloside IV and its main bioactive metabolite, cycloastragenol. Samples were prepared using only 20 μL of mouse plasma and digoxin as an internal standard. After protein precipitation, the supernatant was treated using a phospholipid removal plate to remove ion-suppressive phospholipids. The analytes and internal standard in the filtered solutions were separated on a C18 column and detected under positive ion and selected ion monitoring mode within just 3 min. The assay exhibited good linearity in the concentration range 1–200 ng/mL. The intra- and interday precisions expressed as relative standard deviations were all below 8.6%, and the accuracy expressed as a relative error was ≤8.8%. The method was successfully applied to a pharmacokinetic study of healthy mice upon administration of 30 mg/kg/d astragaloside IV.