Endogenous enzymatic antioxidant status of whiteleg shrimp (Litopenaeus vannamei) following exposure to sublethal concentrations of silver nanoparticles

Abstract

Immunotoxicity of silver nanoparticles (AgNPs) to whiteleg shrimp (Litopenaeus vannamei) was assessed using redox-status orchestrating enzymes. To this end, the shrimp was exposed to sublethal AgNPs concentrations (0 % LC₅₀: control; 25 % LC₅₀: 0.97 mg/L; 50 % LC₅₀: 1.95 mg/L; 75 % LC₅₀: 2.92 mg/L). During the experiment, the behavior of superoxide dismutase (SOD), catalase (CAT), glutathione (GSH), and glutathione peroxidase (GPx) was monitored, besides total antioxidant capacity (TAC) and malondialdehyde (MDA). The hepatopancreas SOD activity reduced about 63 %-76 % at.%50 LC₅₀ and %75 LC₅₀ AgNPs treatments, and CAT decreased in both tissues at 50 % LC₅₀ AgNPs. TAC exhibited a U-form response in the hepatopancreas organ against stress caused by AgNPs, and hepatopancreas MDA displayed a time-dependent increase. Taken together, AgNPs triggered severe immunotoxicity through suppression of CAT, SOD, and TAC in the hepatopancreas tissue.

Keywords: Antioxidant enzymes; Hepatopancreas; Litopenaeus vannamei; Oxidative stress.