Dietary Artemisia arborescens Supplementation Effects on Growth, Oxidative Status, and Immunity of Gilthead Seabream (Sparus aurata L.).

Fish infectious diseases are one of the main constraints of the aquaculture sector. The use of medicinal plants provides a sustainable way of protection using safe, eco-friendly compounds in a more cost-effective way of treatment, compared to antibiotics. The aim of the present study is the assessment of Artemisia arborescens (AA) feed-supplementation effects on gilthead seabream (Sparus aurata). Fish with an average initial body weight of 109.43 ± 3.81 g, were divided into two groups based on AA feed composition (A25 and A50). Following two months of ad libitum feeding, the effect of diets on fish weight and length were measured. Fish serum and mucus were analyzed for non-specific immune parameters (nitric oxide, lysozyme, myeloperoxidase, protease-/anti-protease activity, and complement), antibody responses, oxidative stress (cytochrome P450 1A1, metallothionein), and metabolism markers (total protein, alkaline phosphatase, and glucose). Expression levels of antioxidants (sod1, gpx1), cytokines (il-1b, il-10, tfgb1, and tnfa), hepcidin, and heat shock protein grp75 genes were measured in spleen samples. A results analysis indicated that A. arborescens use as a feed supplement has a compromised positive effect on the growth performance, immune response, and blood parameters of gilthead seabream. Overall, the suitability of A. arborescens as an efficient food supplement for gilthead seabream health improvement was investigated, setting the basis for its application assessment in Mediterranean aquaculture.

Breeding Substrate Containing Distillation Residues of Mediterranean Medicinal Aromatic Plants Modulates the Effects of Tenebrio molitor as Fishmeal Substitute on Blood Signal Transduction and WBC Activation of Gilthead Seabream (Sparus aurata).

This work assesses the dietary use of two insect meals of Tenebrio molitor (TM) larvae reared in conventional (TM-10) or MAP-enriched substrates (MAP-TM-10) as fish meal replacements (10%) in the diets of gilthead seabream (Sparus aurata). Fish (n = 4500; 207.19 ± 1.47 g) were divided into three groups with triplicates: control (fed conventional diet), TM-10, and MAP-TM-10 groups. The fish were reared in floating cages for 12 weeks and the dietary effects on white blood cell activation, heat shock proteins, MAPKs, and apoptosis of the fish were evaluated. The MAP-TM-10 group exhibited the highest eosinophilic induction. Phosphorylated levels of p38 MAPK, p44/42 MAPK, HSP70, and HSP90 increased in the TM-10 and MAP-TM-10 groups. In terms of apoptosis, Bax levels were lower in the TM groups compared to the control, and the MAP-TM-10 group showed even lower levels than the TM-10 group. Bcl-2 levels increased in the TM-10 group compared to the control, and further increased in the MAP-TM-10 group. The Bax/Bcl-2 ratio, an apoptosis indicator, decreased in the TM groups, with the MAP-TM-10 group showing a further decrease compared to TM-10. These findings suggest that insects' breeding substrate being enriched with MAPs modulated the effect of TM on cellular stress and apoptosis.