RESUMEN
Objective An investigation was conducted to assess the chemopreventive effects of celecoxib, a selective cyclooxygenase(COX)-2 inhibitor, on a rat colon carcinogenesis model induced by dimethylhydrazine (DMH). The results were compared with those of sulindac. Methods Thirty-two 8-week-old female Sprague-Dawley rats were randomly divided into four groups (n=8 each):Group A rats were treated with DMH(120 mg/kg wt, single subcutaneous injection) alone and group B rats were treated with saline alone. Group C rats were pre-treated with sulindac (320 mg/kg feedstuff) and group D rats pre-treated with celecoxib (1500 mg/kg feedstuff) for 7 days before DMH initiation. The animals were killed at the end of the experiment (week 5) and the aberrant crypt foci(ACF) and aberrant crypt(AC) of the colonic mucosa were assessed after being stained with methylene blue. Results In group A(DMH only), the average numbers of ACF and AC were 182.4?93.43 and 262.8?197.8 respectively. In group B (saline group) rats, no ACF was found. In group C (sulindac group) rats, the average numbers of ACF and AC were 91.25?48.98 and 139.60?68.52 respectively, both of them were decreased significantly as compared with those in Group A (P