The experimental study of Astragalus membranaceus on meridian tropsim: The distribution study of astragaloside IV in rat tissues

According to Traditional Chinese Medicine (TCM) theories, TCM with different meridian tropism have different therapeutic effects. In view of the meridian tropism of Astragalus membranaceus (Huangqi), astragaloside IV, one of the effective phytochemicals of Huangqi, was appointed and observed its distribution in rat tissues following a single intravenous (i.v.) dose. A simple and accurate LC-ESI-MS/MS method was developed and validated for astragaloside IV quantification in heart, liver, spleen, lung and kidney using warfarin as an internal standard (IS). Chromatographic separation was performed on a Eclipse plus C18 (4.6 mm × 100 mm, 1.8 μm) when the flow rate was set at 0.300 mL min−1 and ammonium acetate aqueous solution - acetonitrile was used as mobile phase. The intra- and inter-day precisions of the quality control samples were within 15% and accuracies were within 90.0–110%. The recoveries were more than 90.0% at high, medium and low concentrations, respectively. This method was successfully applied for distribution of astragaloside IV after intravenous (i.v.) dose of 4 mg kg−1 astragaloside IV in rats. Astragaloside IV concentration was highest in liver and kidney and remained much higher than that in other tissues over the experiment course. Lung, heart and spleen were also detected to contain astragaloside IV. The results clearly demonstrated that astragaloside IV was one of the material bases of the meridian tropism of Huangqi.