Effects of omega fatty acids on the short-term postprandial satiety related peptides in rats

We aimed to assess the effects of omega fatty acids on time depending on responses of satiety hormones. Sixty adult rats were randomly divided into 4 groups; linoleic acid (LA), α-linolenic acid (ALA), eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) groups. For each fatty acid, the dose of 400 mg/kg was applied by oral gavage. Blood samples were taken after the 15, 30, 60 and 120 minutes. Ghrelin, cholecystokinin (CCK), glucagon-like peptide-1 (GLP-1), peptide YY (PYY), leptin and insulin hormones were analyzed by ELISA. We observed the significant increases (p<0.05) of the levels of CCK between n-3 (ALA, at 60^th min; EPA, at 30^th and 60^th min and DHA, at 60 min) and n-6 (LA) supplemented rats. The highest GLP-1 levels were in ALA (0.70 ng/mL) and DHA (0.67 ng/mL) supplemented groups at 60^th and 120^th min indicating n-3 fatty acids efficiency on satiety compared to LA. It seems that ALA at 60^th min and EPA at 120^th min could provide the highest satiety effect with the highest insulin response, while the efficiency of LA supplementation on insulin-induced satiety diminished. The only significant change in AUC values among all hormones was in the CCK of the ALA group (p=0.004). The level of leptin increased in DHA and EPA supplemented rats (p=0.140). Our results showed that dietary omega fatty acids influenced the releasing of hormones in different ways possibly depending on chain length or saturation degree. Comprehensive studies need to be addressed for each fatty acid on satiety-related peptide hormones.