Therapeutic effect of Sijunzi decoction on ulcerative colitis: A study based on in vitro functional experiments

Purpose: To investigate the efficacy of Sijunzi decoction (SJZD) against ulcerative colitis (UC) in vitro, and to unravel the probable mechanism of action.Methods: SEC-6 cells were exposed to lipopolysaccharide (LPS) in order to establish an ulcerative colitis model, and then treated with SJZD. CCK-8 assay was employed to evaluate cell viability, while cell apoptosis was determined by flow cytometry. Enzyme-linked immunosorbent assay (ELISA) and quantitative real-time polymerase chain reaction (qRT-PCR) were used to assess inflammation factors, viz, TNF-α, IL-1β and IL-6, whereas the expression levels of Bax, Bcl-2 and peroxisome proliferatoractivated receptors (PPARs) were evaluated by Western blot.Results: SJZD doses of 80 and 160 mg/L increased cell viability in LPS-induced SEC-6 cells, while Bcl2 and Bax expressions were regulated, and apoptosis inhibited at these doses (p < 0.05), indicating that SJZD attenuated cell apoptosis. Inflammation was also repressed by SJZD, based on the reduced expressions of TNF-α, IL-1β and IL-6 (p < 0.05). Furthermore, SJZD significantly increased PPARα level, thus enhancing cell viability, inhibiting apoptosis as well as inhibiting inflammation (p < 0.05).Conclusion: SJZD lowers cell damage, and inhibits cell apoptosis and inflammation through the activation of PPARα pathway, thus suggesting that SJZD is a potential therapeutic candidate for the treatment of ulcerative colitis.