Combined therapeutic efficacy of carvacrol and X-radiation against 1,2-dimethyl hydrazine-induced experimental rat colon carcinogenesis.

Colon cancer is one of the most commonly diagnosed cancers, and is a major cause of cancer morbidity and mortality worldwide. The objective of the present study is to evaluate the combined therapeutic efficacy of carvacrol (CVC) and X-radiation against 1,2-dimethylhydrazine-induced colon cancer. Male albino Wistar rats were randomly divided into six groups. Group 1 served as control; group 2 received 40 mg/kg b.wt of CVC orally everyday throughout the experimental period (32 weeks); groups 3-6 received subcutaneous injections of DMH (20 mg/kg b.wt), once a week for the first 15 weeks; group 4 received a single dose of X-radiation at the 31st week; group 5 received CVC (40 mg/kg b.wt) two days after the last injection of DMH and continued everyday till the end of the experimental period; group 6 received CVC as in group 5 and radiation as in group 4. DMH-treated rats showed increased incidence of aberrant crypt foci (ACF), dysplastic aberrant crypt foci (DACF), mast cell number, argyrophilic nucleolar organizer regions; elevated activities of phase I enzymes, decreased activities of phase II enzymes, decreased mucin content and altered colonic and liver histology as compared to control rats. Though the individual treatments with CVC and X-radiation to DMH-treated rats reversed the above changes, the combined treatment with both CVC and X-radiation showed a marked effect. Our findings emphasize the potential role of combined therapeutic effect of CVC and X-radiation against DMH-induced colon carcinogenesis.