Pharmacological investigation of a HPLC/MS standardized three herbal extracts containing formulae (Bu-Shen-Yi-Qi-Tang) on airway inflammation and hypothalamic-pituitary-adrenal axis activity in asthmatic mice

Bu-Shen-Yi-Qi-Tang (BSYQT) which is prescribed on the basis of clinical experience is commonly used in clinic of traditional Chinese medicine (TCM) for asthma treatment. The components of BSYQT include Radix Astragali (RA), Herba Epimedii (HE) and Radix Rehmanniae (RR). The aim of this study was to screen extracts of BSYQT with best anti-inflammatory activity in asthmatic mice, and separate and identify the chemical compounds in them. Our results suggested that 60% ethanol extract of herbs (H60) and granules (G60) of BSYQT were the two extracts with best anti-inflammatory activity and effects of H60 were a little better than that of G60. High-performance liquid chromatography coupled to electrospray ionization and quadrupole time-of-flight mass spectrometry (HPLC–ESI-Q-TOF-MS/MS) analysis of the major chemical compounds of H60 and G60 revealed that 56 and 42 peaks were identified separately in H60 and G60. Further analysis revealed that 38 compounds were identified shared by H60 and G60, and 18 compounds were only in H60. There were 25 compounds in HE, 6 compounds in RR and 7 compounds in RA in the 38 compounds shared by G60 and H60. These 38 chemical components were tentatively considered the material basis of the anti-inflammatory activity of G60 and H60. The differences in the amount of the 38 chemical components as well as the 18 chemical components only in H60 were tentatively considered responsible for the activity differences between H60 and G60. In conclusion, these results suggested that extracts of BSYQT had inhibitory effects on airway inflammation in asthmatic mice, and H60 and G60 demonstrated the best anti-inflammatory activity. The 38 chemical compounds shared by H60 and G60 were responsible for their anti-inflammatory activity in asthmatic mice, and the differences in chemical compounds contents and amounts between H60 and G60 were responsible for this activity differences. This work would provide support for further pharmacodynamic material basis study of BSYQT.