OBJECTIVE  To investigate the effects of Polygonum Cuspidatum in the treatment of lung fibrosis mice infected with the respiratory syncytial virus (RSV) in terms of altered lipids and the inflammatory process in the lung.

  METHODS  C57BL/6 mice were given a tracheal drip of 50 μL RSV venom (4×10⁶ PFU·mL^-1) combined with bleomycin (2 mg·mL^-1). The mice were randomly divided into blank group, bleomycin induced pulmonary fibrosis group, RSV infected pulmonary fibrosis group and Polygonum Cuspidatum (4.55 g·kg^-1·d^-1) treatment group. To assess changes in pathological and pro-inflammatory cytokine levels (IL-6, and TNF-α), lung tissues from each group were removed 21 days after modeling. Lipidomics analysis was then completed using UPLC-Q Exactive Orbitrap/MS.

  RESULTS  In comparison to the blank group, the lungs of the bleomycin induced pulmonary fibrosis group and RSV infected pulmonary fibrosis group showed prominent collagen fiber deposition and inflammatory infiltration, and the levels of lung inflammatory factors like IL-6 and TNF-α were noticeably higher (P < 0.05). The lipid metabolism of the RSV infected pulmonary fibrosis group differed significantly from that of the bleomycin induced pulmonary fibrosis group, with abnormal levels of ceramide (Cer), phosphatidylcholine (PC), phosphatidylethanolamine (PE), phosphatidylinositol (PI), acylethanolamine (NAE), sphingomyelin (SM), diglyceride (DG), triglyceride (TG) and fatty acid (FA). The above indexes showed a significant trend of correction after the intervention of Polygonum Cuspidatum (4.55 g·kg^-1·d^-1).

  CONCLUSION  RSV has the potential to accelerate the progression of pulmonary fibrosis. Polygonum Cuspidatum reduces inflammation and collagen deposition in the lung tissue of RSV-infected mice with pulmonary fibrosis by regulating lipid metabolism, and it slows the progression of pulmonary fibrosis in mice.