Effect of dietary supplementation of vitamin C-loaded chitosan nanoparticles on growth, immune-physiological parameters, and resistance of white shrimp Litopenaeus vannamei to Vibrio harveyi challenge

Abstract

The goal of this research was to determine the effect of dietary supplementation of vitamin C-loaded chitosan nanoparticles (VC-CSNPs) on the antioxidant activity, disease resistance, non-specific immunity, and gene expression of the whiteleg shrimp Litopenaeus vannamei which was fed for eight weeks and challenged with Vibrio harveyi. Antioxidants included in food were believed to reduce oxidative stress and boost immunity. CSNPs and VC-CSNPs were prepared by ionotropic gelation method and the particles were characterized by FTIR, Scanning electron microscopy (SEM), and Zetasizer analysis. The results confirmed the formation of spherical structure of VC-CSNPs with a mean particle size in the range of 95–100 nm, respectively having positive zeta potential (+ 29.84 mV). Vitamin C (VC), a crucial antioxidant was incorporated into Chitosan nanoparticles (CSNPs) to increase its bioavailability and was treated orally to L. vannamei which was both challenged and nonchallenged by Vibrio harveyi. These experimental tests showed that nonchallenged shrimp fed vitamin C-loaded chitosan nanoparticles (VC-CSNPs) showed considerably improved (p ≤ 0.05) body weight, level of food efficiency, and survival percentage. Shrimp fed VC-CSNPs showed a significant improvement (p ≤ 0.05) in immunological parameters such as phenoloxidase, transglutaminase, respiratory burst, total hemocyte counts, and disease resistance. In addition, substantial improvement of relative gene expression of lectin, lysozyme, and cMnSOD was detected in the VC-CSNPs fed groups. Results pointed out that the combination of vitamin C and CSNPs exerted immunostimulatory effects on shrimp (L. vannamei) and could be used as a dietary supplement for pathogenic aquatic organisms.