Magnolol exerts anti-inflammatory effect in the animal model of rheumatoid arthritis

As a typical inflammatory arthritis, rheumatoid arthritis (RA) reduces the life quality of patients from all over the world. Magnolol has been reported to exert the anti-inflammation role in several diseases. Here, we aim to investigate the effect of magnolol on the inflammatory response in vivo and in vitro. Indicators like arthritic index and paw weight were measured after collagen-induced arthritis (CIA) induction and magnolol treatment. The tissues of the rats' left hind paws were subjected to hematoxylin & eosin staining to observe the morphological changes. The serum inflammatory cytokines and MH7A cells were evaluated by enzyme-linked immunosorbent and real time quantitative polymerase chain reaction. Cell viability assay and flow cytometry were prepared for evaluating the viability and apoptosis of MH7A cells, respectively. Magnolol alleviated the paw inflammation and joint swelling in CIA rat model. CIA-induced upregulation of the serum inflammatory markers was also significantly reduced by magnolol in polyarthritis rat model. For in vitro experiments, magnolol treatment enhanced the viability and decreased apoptosis of tumor necrosis factor-alpha (TNF-α)-stimulated MH7A cells. Inflammatory cytokines were also downregulated by magnolol in TNF-α-stimulated MH7A cells. Magnolol alleviated RA development by inhibiting inflammatory response in CIA-induced rat model or TNF-α-treated MH7A cells.