Published online Sep 7, 2020. doi: 10.3748/wjg.v26.i33.4945
Peer-review started: May 17, 2020
First decision: June 18, 2020
Revised: June 27, 2020
Accepted: August 12, 2020
Article in press: August 12, 2020
Published online: September 7, 2020
Intestinal mucosal barrier dysfunction plays an important role in the pathogenesis of ulcerative colitis (UC). Recent studies have revealed that impaired autophagy is associated with intestinal mucosal dysfunction in the mucosa of colitis mice. Resveratrol exerts anti-inflammatory functions by regulating autophagy.
To investigate the effect and mechanism of resveratrol on protecting the integrity of the intestinal mucosal barrier and anti-inflammation in dextran sulfate sodium (DSS)-induced ulcerative colitis mice.
Male C57BL/6 mice were divided into four groups: negative control group, DSS model group, DSS + resveratrol group, and DSS + 5-aminosalicylic acid group. The severity of colitis was assessed by the disease activity index, serum inflammatory cytokines were detected by enzyme-linked immunosorbent assay. Colon tissues were stained with haematoxylin and eosin, and mucosal damage was evaluated by mean histological score. The expression of occludin and ZO-1 in colon tissue was evaluated using immunohistochemical analysis. In addition, the expression of autophagy-related genes was determined using reverse transcription-polymerase chain reaction and Western-blot, and morphology of autophagy was observed by transmission electron microscopy.
The resveratrol treatment group showed a 1.72-fold decrease in disease activity index scores and 1.42, 3.81, and 1.65-fold decrease in the production of the inflammatory cytokine tumor necrosis factor-α, interleukin-6 and interleukin-1β, respectively, in DSS-induced colitis mice compared with DSS group (P < 0.05). The expressions of the tight junction proteins occludin and ZO-1 in DSS model group were decreased, and were increased in resveratrol-treated colitis group. Resveratrol also increased the levels of LC3B (by 1.39-fold compared with DSS group) and Beclin-1 (by 1.49-fold compared with DSS group) (P < 0.05), as well as the number of autophagosomes, which implies that the resveratrol may alleviate intestinal mucosal barrier dysfunction in DSS-induced UC mice by enhancing autophagy.
Resveratrol treatment decreased the expression of inflammatory factors, increased the expression of tight junction proteins and alleviated UC intestinal mucosal barrier dysfunction; this effect may be achieved by enhancing autophagy in intestinal epithelial cells.
Core tip: We established a chronic colitis model successfully via administration of dextran sulfate sodium (DSS), and we found that resveratrol ameliorates the production of the inflammatory cytokines in DSS-induced colitis mice. Meanwhile, resveratrol treatment alleviated intestinal mucosal barrier dysfunction in DSS-induced colitis and increased the expression of the tight junction proteins occludin and ZO-1. Further studies showed that resveratrol treatment increased the levels of LC3B and Beclin-1 in the colons of colitis mice, as well as the number of autophagosomes, which may via enhancing autophagy.