Acta Vet. Brno 2007, 76: 613-618

Etoricoxib in the Prevention of Rat Mammary Carcinogenesis

P. Orendáš1, I. Ahlers1, P. Kubatka2, E. Ahlersová1, B. Bojková1, M. Kassayová1, L. Friedmanová1, J. Kisková1, I. Ďatelinka1, M. Starostová1

1Department of Animal Physiology, Institute of Biological and Ecological Sciences, Faculty of Science, P.J. Šafárik University, Košice, Slovak Republic
2Department of Pharmacology, Jessenius Faculty of Medicine, Comenius University, Martin, Slovak Republic

Received July 27, 2006
Accepted October 2, 2007

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-Nnitrosourea (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.