Protective effects of pterostilbene on ulcerative colitis in rats via suppressing NF-κB pathway and activating PPAR-γ

Abstract

Our study aimed to investigate the protective effects and potential mechanisms of pterostilbene on rats with ulcerative colitis (UC). We established 2,4,6-trinitrobenzenesulfonic acid (TNBS) induced colitis rat model. Rats were randomly divided into three groups, including control group, model group, and pterostilbene group (30 mg/kg). Disease activity index (DAI) including body weight, stool consistency, and gross bleeding was measured. The concentration of superoxide dismutases (SODs), glutathione superoxide (GSH-px), malondialdehyde (MDA), and methylpropanediol (MPO) in serum were detected by enzyme-linked immunosorbent assay (ELISA). The levels of interleukin-1 beta (IL-1β), IL-17, IL-6, and tumor necrosis factor–alpha (TNF-α) in serum were also analyzed by ELISA kits. Histological evaluations of colons were conducted. The levels of peroxisome-proliferator-activated receptor–γ (PPAR-γ), nuclear factor-κB (NF-κB), ZO-1, and Occludin were analyzed by immunohistochemistry. Compared with model group, pterostilbene notably suppressed the production of TNF-α, IL-17, IL-1β, IL-6, MDA and MPO in serum, and markedly increased the SOD and GSH-Px activity in serum. Pterostilbene significantly attenuated macroscopic damage and histological injury, when compared with model rats. Furthermore, pterostilbene also markedly activated the expression of PPAR-γ, ZO-1, and Occludin, and suppressed the expression of NF-κB. The protective effects of pterostilbene might be associated with suppression of NF-κB and activation of PPAR-γ. Pterostilbene might be a promising therapeutic agent for colitis treatment.