Background: In clinical studies, the combination of methylprednisolone (MP) and cyclophosphamide (CTX) has great benefits for patients with pulmonary fibrosis (PF), but the mechanism of improving PF is not clear.Methods: PF rat models were induced by bleomycin and treated with MP or MP/CTX combination. Transmission electron microscope, hematoxylin and eosin (H&E) and Masson staining were used to measure the morphology of PF. ELISA kits were used to test inflammatory factor levels. MDA, SOD, GSH-PX levels were determined using commercial kits. α-SMA and collagen I levels were examined by western blot and immunohistochemistry. T cells were analyzed with flow cytometry.Results: We found that the combined use of MP and CTX can reduce collagen deposition, α-SMA and collagen I levels in bleomycin induced PF. Moreover, combined treatment with MP and CTX decreased the levels of MDA and inflammatory factors (TNF-α, IL-1 β and IL-6), while increased the activities of SOD and GSH-PX. Further, MP and CTX combination changed T cell types in lung tissues, such as increasing CD4+CD25+Foxp3+ cells.Conclusions: The combination of MP and CTX improved the degree of PF by reducing inflammation, oxidative stress and improving T cell immunity. These findings provide novel insights into the mechanisms by which MP and CTX combination affects PF.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.