Metabolomics Approach to Explore the Effects of Rebamipide on Inflammatory Arthritis Using Ultra Performance Liquid Chromatography/Quadrupole Time-of-Flight Mass Spectrometry

Objective. Rebampide is a gastroprotective agent used to treat gastritis. It possesses anti-inflammatory and anti-arthritis effects, but the mechanisms of these effects are not well understood. The objective of this study was to explore mechanisms underlying the therapeutic effects of rebamipide in inflammatory arthritis. Methods. Collagen-induced arthritis (CIA) was induced in DBA/1J mice. DBA/1J mice were immunized with chicken type II collagen, then treated intraperitoneally with rebamipide (10 mg/kg or 30 mg/kg) or vehicle (10% carboxymethylcellulose solution) alone. Seven weeks later, plasma samples were collected. Plasma metabolic profiles were analyzed using ultra performance liquid chromatography/quadrupole time-of-flight mass spectrometry-based metabolomics study and metabolite biomarkers were identified through multivariate data analysis. Results. Low dose rebamipide treatment reduced the clinical arthritis score compared with vehicle treatment, whereas high dose rebamipide in CIA aggravated arthritis severity. Based on multivariate analysis, 17 metabolites were identified. The plasma levels of metabolites associated with fatty acids and phospholipid metabolism were significantly lower with rebamipide treatment than with vehicle. The levels of $15-deoxy-^{{\Delta}12,14}$ prostaglandin J2 and thromboxane B3 decreased only in high dose-treated groups. Certain peptide molecules, including enterostatin (VPDPR) enterostatin and bradykinin dramatically increased in rebamipide-treated groups at both doses. Additionally, corticosterone increased in the low dose-treated group and decreased in the high dose-treated group. Conclusion. Metabolomics analysis revealed the anti-inflammatory effects of rebamipide and suggested the potential of the drug repositioning in metabolism- and lipid-associated diseases.