Rebamipide is a quinolone derivative that has been commonly used for the treatment of gastric and duodenal ulcers. However, the molecular mechanisms of rebamipide against acetic acid-evoked colitis have not been adequately examined. Hence, the current study aimed to investigate the ameliorative effect of rebamipide in a rat model of acetic acid-evoked ulcerative colitis and the linked mechanisms pertaining to SIRT1/FoxO3a/Nrf2 and PI3K/AKT pathways. Herein, colitis was induced by the intrarectal administration of 3% acetic acid solution in saline (v/v) while rebamipide was administered by oral gavage (100 mg/kg/day) for seven days before the colonic insult. The colonic injury was examined by macroscopical and microscopical examination. The current findings demonstrated that rebamipide significantly improved the colonic injury by lowering the colonic disease activity index and macroscopic mucosal injury score. Moreover, it mitigated the histopathological aberrations and microscopical damage score. The favorable outcomes of rebamipide were driven by combating inflammation evidenced by dampening the colonic expression of NF-κBp65 and the pro-inflammatory markers CRP, TNF-α, and IL-6. In the same context, rebamipide curtailed the colonic pro-inflammatory PI3K/AKT pathway as seen by downregulating the immunostaining of PI3K and p-AKT(Ser473) signals. In tandem, rebamipide combated the colonic pro-oxidant events and augmented the antioxidant milieu by significantly diminishing the colonic TBARS and replenishing GSH, SOD, GST, GPx, and CAT. In the same regard, rebamipide stimulated the colonic upstream SIRT1/FoxO3a/Nrf2 axis by upregulating the expression of SIRT1, FoxO3a, and Nrf2, alongside downregulating Keap-1 gene expression. These antioxidant actions were accompanied by upregulation of the protein expression of the cytoprotective signal PPAR-γ in the colons of rats. In conclusion, the present findings suggest that the promising ameliorative features of rebamipide against experimental colitis were driven by combating the colonic inflammatory and oxidative responses. In perspective, augmentation of colonic SIRT1/FoxO3a/Nrf2 and inhibition of PI3K/AKT pathways were engaged in the observed favorable outcomes.

Objective and design: Prostatic inflammation is the driving force in benign prostatic hyperplasia (BPH). This work investigated the potential modulatory effect of COX-2 inhibition on ADAM-17/EGFR/ERK1/2 axis. Materials or subjects: Adult male Wistar rats were used. Treatment: Celecoxib (10 and 20 mg/kg; i.p.) was injected i.p. daily for three weeks. Testosterone (TST) (3 mg/kg; s.c.) was used to induce BPH. Methods: Prostatic inflammation and hyperplasia were assessed by organ weight and histopathology. Inflammatory mediators were measured using ELISA technique. Protein analysis was performed using western blotting and immunohistochemistry. Gene expression analysis was performed using qRT-PCR. Statistical analyses included one-way ANOVA and Tukey’s multiple comparison test. Results: Testosterone-treated rats had a marked increase in COX-2, prostate weight, and index. Moreover, TST-induced COX-2 was inferred from cytoskeletal changes and was attributable to the overexpression of PGE2, NF-κB (p65), and IL-6. COX-2-derived PGE2 increased the activity of ADAM-17, TGF-α, and TNF-α. Consequently, EGFR–ERK1/2 pathway was over-activated, disrupting anti-apoptotic Bcl-2, cyclin D1, and pro-apoptotic Bax. Celecoxib reversed these effects. Conclusion: COX-2 stimulates the ERK1/2 pathway via PGE2–ADAM-17-catalyzed shedding of TGF-α in testosterone-induced BPH. The results indicate a functional correlation between inflammation and hyperplasia in BPH.