Effect of dietary Arachidonic acid on cortisol, glucose levels and whole Zebrafish (Danio rerio) fatty acid composition

In addition to the development of new technologies to improve the biological conditions of cultured fish, the biochemical nature and physiological functionality of those feed additives strongly affect the stress response. This study explores the effect of dietary arachidonic acid (ARA, 20:4n-6) levels compared with cortisol and glucose levels and whole fatty acid composition in the using Zebrafish as the model organism. Juvenile zebrafish (20-days post-fertilization) fed the five iso-nitrogenous and iso-energetics experimental diets utilizing different ratios of the ARA diet (0, 0.5, 1, 2, and 4% ARA of total fatty acid) for 70 days. Then, Whole-body cortisol and glucose levels were determined, after short-term stress (48 hours’ exposure to starvation). Results showed that the muscle ARA levels were highly correlated to dietary ARA levels. The experiments revealed significant, High ARA levels (2% and 4%) seemed to affect lipid metabolism in complicated ways (p < 0.05). Fish reflected dietary ARA content and post-stress cortisol increased with ARA supply up to 1%, whereas 4% ARA seems to enhance basal cortisol slightly and alter the response to stress. Actually, our results indicate that an ARA-enriched diet induces changes in complex lipids, cortisol and glucose levels, and Overall affect physiological parameters.