Quality control of Hugan capsule based on four-wavelength fusion profiling and electrochemical fingerprint combined with antioxidant activity and chemometric analysis

Improving the quality standard system of herbal preparations (HPs) is an arduous task for the development of traditional Chinese medicine (TCM). At present, an urgent task is to establish a comprehensive, scientific and effective evaluation method for improving the safety, effectiveness and quality consistency of HPs. In this study, Hu Gan capsules (HGCs) were used as an example. Firstly, the three quality markers (Q-markers) in 21 batches of HGCs from 4 manufacturers were determined by HPLC and great difference in content of each sample was found. Furthermore, four-wavelength fusion profiling (FWFP) was established and evaluated by systematically quantified fingerprint method (SQFM). Principal component analysis (PCA) was employed to make a preliminary analysis of the FWFP and distinguish the fluctuation of differences in chemical composition and content. Then, 9 characteristic parameters were recorded through the B-Z oscillating system, and the electrochemical fingerprint (ECFP) was constructed for jointing evaluation with the FWFP, using the equal weight of SQFM results to comprehensively evaluate the sample quality. The 21 batches of samples were divided into four groups and six grades, which indicated that there were significant differences in the content of indicator components and electrochemical active substances in samples. Finally, taking vitamin C as a positive control, 2, 2'-azino-bis (3 - ethyl -benzthiazoline - 6 - sulfonic acid) (ABTS) scavenging assay was applied to study the antioxidant activity of samples. Partial Least Squares (PLS) and bivariate correlation analysis (BCA) were used to analyze the fingerprint-efficacy relationships of FWFP-ABTS and FWFP-ECFP. Consequently, it was found that there were similar antioxidant capacities in electrochemistry and ABTS tests, and 31 of the 40 HPLC fingerprint peaks of HGCs were discovered to have antioxidant activity. The two methods supported each other, to effectively and corporately reflect the antioxidant components in HGCs. In this research, the FWFP and ECFP established could realize the quality detection of HGCs, and provide a novel direction for the improvement of the quality standard of HPs and the research of the quality standard method of TCM.