Protective effect of quercetin encapsulated in chitosan nanoparticles against silver nanoparticle-induced toxicity in Pacific white shrimp (Penaeus vannamei)

Silver nanoparticles (AgNPs), which have been extensively investigated for their antimicrobial properties in aquaculture research, can induce oxidative stress in aquatic organisms. This study assessed the protective effects of dietary quercetin (Qu), quercetin encapsulated in chitosan nanoparticles (Qu-ChiNPs), and chitosan nanoparticles alone (ChiNPs) against AgNP-induced oxidative stress in the Pacific white shrimp, Penaeus vannamei . Shrimp (2.40 ± 0.19 g) were assigned to six experimental treatments, each with three replicates: a negative control (commercial basal diet, no AgNP challenge), a positive control (commercial basal diet, followed by 48 h AgNP challenge at 1 mg L −1 ), and four experimental treatments consisting of 0.5 g kg −1 Qu, 0.25 g kg −1 Qu‑ChiNPs, 0.5 g kg −1 Qu‑ChiNPs, and 0.5 g kg −1 ChiNPs, all of which were also subjected to the AgNP challenge after a 60‑day feeding trial. All parameters were measured after the 48‑h AgNP challenge, and all comparisons were made against the positive control group. The treatment receiving 0.5 g kg −1 Qu-ChiNPs showed significantly lower levels of cholesterol, triglycerides, and alkaline phosphatase, together with increased total protein (+ 30.3%), acid phosphatase (+ 14.2%), phenol oxidase (+ 28.4%), and lysozyme (+ 27.0%) compared to the positive control group ( P < 0.05). In addition, antioxidant parameters such as total antioxidant capacity, superoxide dismutase, catalase and glutathione were significantly enhanced, while malondialdehyde levels were reduced in the group receiving 0.5 g kg −1 Qu-ChiNPs in comparison to the positive control group ( P < 0.05). Amylase, lipase and protease activities were significantly enhanced in shrimp fed 0.5 g kg −1 Qu-ChiNPs compared to the positive control group ( P < 0.05). The findings support Qu-ChiNPs as a practical feed additive to bolster resilience of farmed P. vannamei against nanoparticle exposure and associated oxidative challenges.