Protective Effect of D-Carvone against Dextran Sulfate Sodium Induced Ulcerative Colitis in Balb/c Mice and LPS Induced RAW Cells via the Inhibition of COX-2 and TNF-α.

Abstract

Ulcerative colitis (UC) is an intractable ailment, in which may chronic inflammations/ulcerations may develop in the mucosal lining of the colon with multiple recurrences. Various drugs such as steroids, immunosuppressants, and antibiotics are extensively used to treat UC. The patients suffer from adverse effects of these advanced drugs. So, they need a harmless therapeutic agent from natural sources. The therapeutic D-carvone has an anti-inflammatory action against the investigational colon cancer models. Therefore, we analyzed the effect of D-carvone on dextran sulfate sodium (DSS) provoked colitis model in mice as follows: Group I: noncolitis healthy control mice; Group II: ulcerative colitis mice models; Group III: D-carvone (40 mg/kg) + ulcerative colitis models; Group IV: sulfasalazine (50 mg/kg) + ulcerative colitis models. On the 8th day, the experimental study was terminated and serum samples and colon tissues were processed for further analysis. The effect of D-carvone at different concentration was studied on the LPS challenged RAW 264.7 cell lines. The D-carvone (40 mg/kg) treatment maintained the colon length and decreased disease activity index (DAI) score in UC animals. The increased antioxidant enzymes status and decreased oxidative stress and pro-inflammatory markers were noted in the D-carvone (40 mg/ kg) + UC mice. Histopathological study of colon tissue of D-carvone (40 mg/kg) treated UC mice displayed less mucosal damage and improved crypt integrity and goblet cells compared with DSS only provoked mice. The im-munohistochemical expression of iNOS and COX-2 was drastically diminished in the D-carvone treated UC mice. D-carvone (40 mg/kg) treatment appreciably diminished the LPS provoked NO production and pro-inflammatory modulators in the RAW 264.7 macrophage cell lines. These findings proved that D-carvone has a potential therapeutic effect to prevent LPS induced inflammation in in vitro cells and chemically induced ulcerative colitis in vivo models.