Flaxseed oil supplementation alters the expression of inflammatory-related genes in dogs

Long chain n-3 fatty acids are beneficial to mammals because of their anti-inflammatory role. However, whether flaxseed oil, which is rich in short chain n-3 fatty acids, has such a role, it has not been extensively examined. This study investigated the supplementation of flaxseed oil on the regulation of genes involved in inflammatory responses such as heat shock proteins (HSP90 and HSP70) and interleukin (IL1β) in the white blood cells of dogs. Five beagles and 5 greyhounds were supplemented with Melrose(®) flaxseed oil at the rate of 100 mL/kg food for 21 days. The blood was collected at day 0, 15, and 22 following supplementation. The expression of 3 genes was quantified using real-time polymerase chain reaction. Plasma concentrations of fatty acids such as alpha linolenic acid, eicosapentaenoic acid, docosahexaenoic acid, linoleic acid, and arachidonic acid were measured, and their correlations with changes in gene expression were determined. Flaxseed oil supplementation downregulated the expression of HSP90 and IL1βin greyhounds but showed no significant effect on these genes in beagles. HSP70 remained unchanged in both breeds following the supplementation. Correlations of HSP90 and IL1βexpression levels with the plasma fatty acid concentrations on day 22 showed a significant negative correlation in greyhounds. Dietary flaxseed oil altered the expression of genes involved in inflammation in white blood cells. Because the expression of the genes may vary in different breeds, it will be useful to consider breed responses to dietary manipulation in canine nutrition management.