Role of elderberry (Sambucus nigra) on the modulation of stress and immune response of Nile tilapia, Oreochromis niloticus

We assessed the role of elderberry extract as a nutraceutical in Nile tilapia to modulate their stress and immune responses under density stress. In the experiment, we maintained tilapia at low (5 g/L) and high population density (120 g/L). We fed half of the low and high-density fish with commercial feed, and the other half, with membrane-separated 13% anthocyanin standardized elderberry extract with maltodextrin excipient, incorporated into commercial feed. We assessed plasma cortisol, blood glucose, IL-2, lysozyme activity, and spleen cell numbers for acute and chronic stress. Among them, blood glucose levels indicated the stress-modulating capability of elderberry in both acute and chronic stress conditions. Plasma cortisol concentrations also demonstrated the potential of elderberry as a stress-modulating agent in chronic stress. Based on our findings, elderberry could potentially be used as a nutraceutical to modulate stress and immune response in vertebrates.