Determination and Pharmacokinetics of Six Anti-Inflammatory Bioactive Constituents of XinFeng Capsule by UHPLC-MS/MS in Adjuvant Arthritis Rats

A simple and sensitive ultra high performance liquid chromatography-electrospray ionization tandem mass spectrometry method (UHPLC-ESI/MS) was developed for the simultaneous determination of six anti-inflammatory bioactive constituents, including astragaloside-II, astragaloside-IV, triptolide, celastrol, wilforgine and wilforine in adjuvant arthritis rat plasma after oral administration of Xinfeng Capsule decoction. Saikosaponin D was used as the internal standard (IS). All analytes and IS were quantitated with positive electrospray ionization and multiple reaction monitoring mode. The linearity range for astragaloside-II, astragaloside-IV, triptolide, celastrol, wilforgine, and wilforine were 2.375-1216, 2-1024, 0.25-64, 1.5-384, 0.75-192 and 0.75-192 ng/mL with intra-day and inter-day precision < 3.5%. The method was fully validated to meet the requirements for bioassay in linearity, accuracy, precision and extraction recovery, and successfully applied to the pharmacokinetic study of six anti-inflammatory bioactive components after oral administration of Xinfeng Capsule decoction to rats.