All-trans Retinoic Acid Protects Mice Against Dextran Sulfate Sodium Induced Colitis

Objictive:Explore the effect of All-trans retinoic acid (ATRA) on dextran sulfate sodium(DSS) induced murine colitis.Methord:The mice were randomly divided into4groups: control, DSS, DSS+ATRA,DSS+LE135. The mice in groups DSS, DSS+ATRA, DSS+LE135were fed with3%DSS(w/v) solution from day1to day8to induce colitis. The group of DSS+ATRAand DSS+LE135were given of ATRA0.5mg/day, LE1350.1mg/day intraperitonealinjection respectively since day3. Disease activity index (DAI) was recorded daily.The expressions of CD68, NF-κB p65, MPO activity, and TNF level in inflamedcolon of each group were measured.Results:1. The DAI of DSS+ATRA(4.63±2.20) is lower than DSS and DSS+LE135（p<0.05）；The DAI of group control is0.2. The histological score of group DSS+ATRA(7.63±1.19) is lower than groupDSS （10.13±1.36）and DSS+LE135（10.38±1.30）（p<0.05）, while higher thancontrol（0.25±0.463）（p<0.05）.3. The MPO activity in colonic tissue of group DSS+ATRA（7.88±0.68）is lowerthan group DSS（11.36±0.96） and DSS+LE135（12.65±0.77）（p<0.05）, higher thancontrol group（3.52±0.58）（p<0.05）。4. The levels of TNF in colonic tissue of group DSS+ATRA（178.63±39.37） islower than group DSS（316.67±43.68） and DSS+LE135（362.45±62.75）（p<0.05）。5. The number of CD68positive cells in lamina propria of group DSS+ATRA issignificantly lower than the DSS group and DSS+LE135（p<0.05）, higher thancontrol group（p<0.05）.6. The number of NF-kB positive cells in lamina propria of DSS+ATRA issignificantly lower than the DSS group and DSS+LE135（p<0.05）, higher than control group（p<0.05）.Conclusion:1. ATRA protects against DSS-induced murine colitis, through inhibiting laminapropria immune cell activation and infiltration of macrophage into colon tissue.