Long term consumption of flaxseed enriched diet decreased ovarian cancer incidence and prostaglandin E2 in hens

Objective. Ovarian cancer is the most lethal gynecological malignancy. Prevention may be the best approach to reduce ovarian cancer. Flaxseed is the richest vegetable source of omega-3 fatty acids which may be effective in the prevention of ovarian cancer. Prostaglandin E-2 (PGE(2)) is the most pro-inflammatory ecoisanoid and one of the downstream products of two isoforms of cyclooxygenase (COX) enzymes: COX-1 and COX-2. Our objective was to determine if long-term consumption of a flaxseed enriched diet decreased ovarian cancer severity and incidence in the laying hen and to investigate its potential correlation with the expression of COX enzymes and PGE2 concentration. Methods. White Leghorn hens were fed 10% flaxseed-enriched or standard diet for 4 years. The severity and incidence of ovarian cancer were determined by gross pathology and histology. COX-1 and COX-2 protein and mRNA expression and PGE(2) concentrations in ovaries were measured by Western blot, quantitative real-time PCR and ELISA, respectively. Results. The results demonstrated that there was a reduction in ovarian cancer severity and incidence in hens fed flaxseed diet. In correlation with decreased ovarian cancer severity and incidence, concentration of PGE(2) and expression of COX-2 were diminished in ovaries of hens fed flaxseed. Conclusions. Our findings suggest that the lower levels of COX-2 and PGE(2) are the main contributing factors in the chemo-suppressive role of long-term flaxseed consumption in ovarian cancer in laying hens. These findings may provide the basis for clinical trials of dietary intervention targeting prostaglandin biosynthesis for the prevention and treatment of ovarian cancer. (C) 2013 The Authors. Published by Elsevier Inc. All rights reserved.