Protection afforded by methanol extract of Calotropis procera latex in experimental model of colitis is mediated through inhibition of oxidative stress and pro-inflammatory signaling

Calotropis procera, a latex producing plant is known to possess medicinal properties including its beneficial effect in gastrointestinal disorders. The anti-inflammatory effect of its latex in various experimental models is noteworthy and in light of this the present study was carried out with an objective to evaluate its efficacy in ulcerative colitis, an inflammatory condition of the colon. Colitis was induced in rats by acetic acid and the rats were divided into four groups where one group served as experimental control and the other groups were treated with two doses of methanol extract of dried latex of C. procera (MeDL; 50 and 150 mg/kg) and mesalazine (MSZ; 300 mg/kg). The study also included normal control (NC) group for comparison of various parameters related to colon like macroscopic changes, ulcer score, adherent mucus content, weight/length ratio, small intestinal transit, oxidative stress and inflammatory markers, tissue histology and immunoreactivity of cyclooxygenase-2 (COX-2), inducible nitric oxide synthase (iNOS) and nuclear factor kappa beta (NF kappa B) subunit p65. Treatment of colitic rats with MeDL produced a significant reduction in colonic mucosal damage as revealed by macroscopic and microscopic evaluation and normalization of tissue levels of oxidative stress markers and pro-inflammatory mediators. The protection afforded by MeDL was also evident from its restorative effect on tissue histology and expression of COX-2, iNOS and NF kappa B(p65). This study shows that by targeting oxidative stress and NF kappa B(p65) mediated pro-inflammatory signaling, the latex of C. procera affords protection in colitis and its effect was comparable to that of mesalazine. This study suggests that latex of C. procera could serve as a promising therapeutic option for treating inflammatory conditions of the colon.