Folic Acid-Coated Nanochitosan Ameliorated the Growth Performance, Hematological Parameters, Antioxidant Status, and Immune Responses of Rainbow Trout (Oncorhynchus mykiss)

Dietary nanocomposite of vitamin C and vitamin E enhanced the performance of Nile tilapia

Nowadays, nanomaterials enter high numbers of daily used products and drug manufacture. A nanocomposite of vitamins C (VC) and vitamin E (VE) with chitosan as a vehicle and protector was used in a comparative eight-week feeding study, Nile tilapia weighing 31.2 ± 0.36 g distributed in seven groups and fed (G1) basal diet, (G2) bulk VC, (G3) VC- nanoparticles (NPs), (G4) bulk VE, (G5) VE-NPs, bulk VCE (G6), and (G7) VC plus VE (VCE)-NPs, respectively. The Nile tilapia-fed nanocomposite vitamins had significantly higher growth performance compared to the control; VCE-NPs had the superiority among tested supplementations where total weight gain (63.6 g), daily weight gain (1.13 g), relative growth rate (206.1%) with lower feed conversion rate (1.6) and insignificant feed intake (101.5 g). Overall, the level of liver enzymes was significantly decreased in fish serum after eight-week nanocomposite supplementation, and dietary VCE-NPs caused a significant reduction of serum AST (18.45 IU/L) and ALT (14.77 IU/L) compared to the control 25.5 IU/L and 17.6 IU/L, respectively. Fish fed dietary VCE-NPs, VC-NPs, and VE-NPs had significant enhancement of RBCs 4.2 × 106/μL, 3.8 × 106/μL, and 3.55 × 106/μL; WBCs 46.15 × 103, 42.9 × 103, and 44 × 103/μL, respectively, Also TP was significantly higher 6.38 g/dL in VCE-NPs group compared to the control and the other treatments. Over all, the dietary nanocomposite vitamins boost the innate immunity of the experimental Nile tilapia, the oxidative burst activity (OBA), phagocytic activity (PA), phagocytic index (PI), and serum antibacterial (SAA) were significantly increased compared to those received bulk vitamins and the control. The activity of antioxidant biomarkers in fish serum including glutathione peroxidase (GPx), catalase (CAT), superoxide dismutase (SOD), total antioxidant capacity (TAC), glutathione reductase (GR), and myeloperoxidase (MPO) showed a rise in the serum of Nile tilapia received nano- and bulk-form of VC and VCE compared to the control and both forms of VE. Furthermore, the level of malondialdehyde (MDA), reduced glutathione (GSH), and oxidized glutathione (GSSG) were significantly increased in the fish serum following the trend of antioxidants enzymes. In conclusion, a dietary nanocomposite of vitamin C and vitamin E enhanced Nile tilapia's growth performance and feed utilization. It could also improve health status and immune response. The values of antioxidant biomarkers indicated that the nanocomposite could help the fish body scavenge the generated reactive oxidative species (ROS).

Therapeutic Intervention with Dietary Chitosan Nanoparticles Alleviates Fish Pathological and Molecular Systemic Inflammatory Responses against Infections

Marine bio-sourced chitosan nanoparticles (CSNP) are antimicrobial and immunomodulatory agents beneficial for fish medicine. Herein, dietary CSNP was investigated for the amelioration of the systemic inflammatory responses of an induced fish model. One hundred and forty-four rainbow trout were assigned to one pathogen-free and non-supplemented group (negative control), and three challenged groups: non-supplemented (positive control), CSNP-preventive, and CSNP-therapeutic. After a feeding experiment extended for 21 days, the organosomatic indices (OSI) and molecular aspects were assessed. After a challenge experiment extended for further 28 days, CSNP-therapeutic intervention was assessed on fish survival and systemic inflammatory responses on pathology, histo-morphology, and molecular aspects. With CSNP administration, OSI nonsignificantly decreased and the relative expression of targeted inflammatory-mediator genes was significantly increased. The CSNP-therapeutic fish showed an RPS of 80% as compared to the positive control group, and CSNP-therapeutic administration retained the highest gene expression augmentation up to 28 days after the challenge. Notably, the splenic reticulin fibers framework of the CSNP-therapeutic group retained the highest integrity among the groups during the infection. After recovery, reticulin fibers density in the CSNP-therapeutic samples was significantly higher than in the negative control group, which indicates high innate immunity. Thus, CSNP showed promising biotherapeutic features enhancing fish resistance against infections.