Pristimerin reduces dextran sulfate sodium-induced colitis in mice by inhibiting microRNA-155.

Pristimerin (Pris), which is a natural triterpenoid compound extracted from the Celastraceae plant, has an effect on intestinal inflammation, but its mechanism needs further study. Human genome-wide analysis found that the expression of microRNA-155 in the blood and colon tissue of patients with IBD was increased. Therefore, we studied the effect of Pris on a model of DSS-induced colitis in mice and investigated whether Pris inhibited the expression of microRNA-155. We obtained a mouse model of acute experimental colitis by allowing the mice to drink a 3% by mass DSS solution freely for 7 days. Pris solutions at different concentrations were injected via the abdomen to simulate the therapeutic effect of Pris on colitis. The body weight and faeces were measured and recorded daily. The mice were sacrificed by the cervical dislocation method after the experiment, and the colon length and histological changes, as well as the changes in Nrf2 in the colon tissue, were measured. The activities of the antioxidant enzymes GSH, GSH-Px and SOD were examined. The expression levels of microRNA-155, IL-1β, IL-6, IL-17, and TNF-α in the colon were detected by RT-PCR technology, and the expression of NF-κB p65 in the colon was detected by western blotting. Our study shows that Pris can reduce the DAI score, obviously alleviate weight loss, and decrease the colon pathological tissue damage caused by DSS. Pris can inhibit the increase in microRNA-155 expression induced by DSS-induced colitis. Our study has shown that Pris may reduce DSS-induced colitis in mice by inhibiting the expression of microRNA-155, and further inhibition of the inflammatory response and oxidative stress occurred.