Anti-inflammatory effect of wedelolactone on DSS induced colitis in rats: IL-6/STAT3 signaling pathway

Wedelolactone, main active constituent of Wedelia calendulace and Eclipta alba plants which has been traditionally used to treat various chronic inflammatory conditions. However, its mechanism of action of anti-inflammatory effect on ulcerative colitis is yet to be established.

In the present study, the effect of the wedelolactone on the myeloperoxidase activities and in the production of proinflammatory cytokines involved in the pathogenesis of chronic inflammation was assessed.

Wistar rats were randomly divided into four groups containing six animals per group. Group I (Vehicle control): tap water and vehicle; Group II (DSS control): tap water containing 5% (w/v) of DSS over 7 days, and vehicle; Group III (treatment group): Wedelolactone 50 mg/kg/day, and tap water containing 5% DSS over 7 days, Group IV (treatment group): Wedelolactone 100 mg/kg/day and tap water containing 5% DSS over 7 days over the experiment.

Study revealed that wedelolactone treatment dramatically decrease the release of IL-1a, IL-1b, IL-2, TNF, INFγ, STAT3 and CCL-5 in colons treated with DSS. In summary, these results suggest that the inhibition of IL-6/STAT3 signaling is a potential mechanism by which wedelolactone is used in the treatment of ulcerative colitis.

Oral administration of Wedelolactone (100 mg/kg) significantly attenuated pathological colonic damage and inhibited inflammatory infiltration, myeloperoxidase activities. In summary, Wedelolactone showed anti-inflammatory effect by down regulation of the IL-6/STAT3 inflammatory signaling pathway. These findings provide new insights into the pharmacological actions of wedelolactone as a potential therapeutic agent for colitis.