Carvacrol exhibits anti-oxidant and anti-inflammatory effects against 1, 2-dimethyl hydrazine plus dextran sodium sulfate induced inflammation associated carcinogenicity in the colon of Fischer 344 rats

Abstract

Chronic inflammation is one of the remarkable etiologic factors for various human ailments including cancer. The well known hypothesis is that persistent inflammation in colon can increase the risk of colorectal cancer (CRC). In this study, a pharmacological evaluation of carvacrol, a phenolic monoterpene constituent of essential oils produced from aromatic plant Oreganum vulgarea sp. on colitis associated colon cancer (CACC) induced by 1,2 Dimethylhydrazine (DMH) and dextran sodium sulfate (DSS) in male Fischer 344 rat model was studied. F344 rats were given three subcutaneous injections of DMH (40 mg/kg body wt) in the first week and were given free access to drinking water containing 1% DSS for the next one week followed by 7-14 days of water as three cycles. Carvacrol was administrated before and after tumor induction at a concentration of 50 mg/kg body weight (o.p). Carvacrol treated groups promotes the endogenous antioxidant system and suppress the inflammation in DMH/DSS induced animals. An increased antioxidant status and restoration of histological lesions in the inflamed colonic mucosa was observed in carvacrol treated rats. This effect was confirmed biochemically by reducing free-radical accumulation and suppressing expression of pro-inflammatory mediators. In this study, Carvacrol significantly increased the anti-oxidant enzymes such as superoxide dismutase (SOD), catalase (CAT) glutathione (GSH) levels and reduced lipid peroxides (LPO), myeloperoxidase (MPO) and nitric oxide (NO) as compared to DMH/DSS induced rats. These dramatic changes facilitate the suppression of pro-inflammatory mediators such as inducible nitric oxide synthase (iNOS), and interleukin-1 beta (IL-1β) in CACC induced rats. Taken together, these findings suggest that Carvacrol may play a beneficial role in DMH/DSS induced experimental rat model and serve as an excellent dietary antioxidant as well as anti-inflammatory agent. It may represent novel therapeutic interventions against colon cancer triggered by chronic inflammation.

Keywords: Carvacrol; Colitis; Colon cancer; Dextran sodium sulfate; Dimethyl hydrazine; Inflammation.