Suppression of Intestinal Polyp Development by Nimesulide, a Selective Cyclooxygenase‐2 Inhibitor, in Min Mice

Nonsteroidal anti‐inflammatory drugs (NSAIDs) suppress colon carcinogenesis in man and experimental animals. However, conventional NSAIDs inhibit both cyclooxygenase (COX) isoforms, COX‐1 and COX‐2, and cause gastrointestinal side‐effects. Nimesulide, a selective inhibitor of COX‐2, is much less ulcerogenic. We, therefore, examined its influence on the development of intestinal polyps in Min mice. Female Min mice at 4 weeks old were given 400 ppm nimesulide in their diet for 11 weeks. This treatment resulted in a significant reduction of the numbers of both small and large intestinal polyps, the total being 52% of that in untreated control Min mice. The size of the polyps in the nimesulide‐treated group was also significantly decreased. The results suggest that nimesulide is a good candidate as a chemopreventive agent for human colon cancer with low toxicity.