Mechanisms of bergenin treatment on chronic bronchitis analyzed by liquid chromatography-tandem mass spectrometry based on metabolomics.

With increasing air pollution, chronic bronchitis (CB) has become a major public health problem worldwide. Previous studies have shown beneficial effects of Bergenin (Ber) on chronic bronchitis. To facilitate understanding of the pathogenesis underlying CB as well as to elucidate the Ber therapeutic mechanism, it is crucial to confirm the rational biomarkers of CB and its treatment. This study aimed to investigate the preventive chronic bronchitis mechanism of Ber by applying a serum metabolomics strategy. In this study, 18 Sprague-Dawley rats were randomly divided into three groups,with six rats in each group. Rats from the CB and Ber groups were exposed to tobacco smoke for 1 hd^-1 (1 h per day) for 28 days. Ber was administered orally to Ber rats 3 h after exposure every day, and the others were administered water. According to the morphometric analysis of the airway epithelium and the count of white blood cells in the bronchoalveolar lavage fluid, Ber suppressed the infiltration of inflammatory cells, inhibited the secretion of mucus, and reduced white blood cells in bronchoalveolar lavage fluid. The metabolic profiles of sera were analyzed by multivariate statistical analyses, including PCA, PLS-DA and OPLS-DA models, and revealed that the levels of thirteen metabolites were significantly changed and identified as potential biomarkers in the CB group and Ber group. The results suggested that the therapeutic mechanism of Ber may be related to the regulation of dysfunctions in glycerophospholipid, tryptophan, arginine and proline metabolism induced by CB, and changes in arachidonic acid metabolism.