Etoricoxib in the prevention of rat mammary carcinogenesis

Abstract

Several experimental studies suggest that non-steroidal antiinflammatory drugs have chemopreventive effects in mammary carcinogenesis. In this study, tumour suppressive effects of a selective inhibitor of cyclooxygenase-2 (COX-2) etoricoxib in the prevention of N-methyl-N-nitrosourea (NMU)-induced mammary carcinogenesis in Sprague-Dawley rats were evaluated. Etoricoxib was administered in the diet, at two concentrations: 1) 0.01 mg/g (ETO 0.001%) and 2) 0.025 mg/g (ETO 0.0025%). Although the chemopreventive effects were not statistically significant, remarkable tumour suppressive effects with the concentration of ETO 0.0025% were recorded. The incidence decreased by 4.31% and tumour frequency per group decreased by 6.67% when compared to the control group. Latency (the period from carcinogen administration to the first tumour appearance) increased by 7.28% in dose-dependent manner. The results of our experiments point to dose-dependent tumour suppressive effects of a higher concentration of etoricoxib (ETO 0.0025%) when compared to the control group. They suggest that higher etoricoxib concentrations may enhance its tumour suppressive effects.