Spirulina platensis Alleviated the Oxidative Damage in the Gills, Liver, and Kidney Organs of Nile Tilapia Intoxicated with Sodium Sulphate

SIMPLE SUMMARY: Nile tilapia (Oreochromis niloticus) are expected to suffer from oxidative stress induced by sodium sulphate in the ecosystem. Herein, we proposed that dietary Spirulina platensis could relieve the impacts of sodium sulphate on tilapia. The hepatic antioxidative and related activities were decreased under sodium sulphate exposure. However, dietary S. platensis alleviated the tissue antioxidative overexpression compared to the sodium sulphate and control groups. This study implies that natural dietary antioxidants can be applied in aquatic organisms to alleviate the features induced by toxicants and xenobiotics. ABSTRACT: The current study aimed at assessing the recuperative roles of dietary Spirulina platensis on the antioxidation capacity of Nile tilapia (Oreochromis niloticus) exposed to sodium sulphate for eight weeks. In brief, fish were allocated into four groups with three triplicates per group, where a group fed on a commercial basal diet served as control, a group was intoxicated with sodium sulphate (SS) 5.8 mg/L, another group was fed a diet supplemented with 1% S. platensis (SP), and the last group was fed 1% SP and concomitantly intoxicated with 5.8 mg/L sodium sulphate (SP/SS). Tissue antioxidative indices of each fish were measured as follows: glutathione peroxidase (GSH-Px) activity in muscles, catalase (CAT) and superoxide dismutase (SOD) activities in gills, and total antioxidant capacity (T-AOC) in the liver and kidney. Moreover, the expression of hepatic SOD, GSH-Px, and glutathione-S-transferase (GST) genes was also determined. It was found that tissue CAT, SOD, and GSH-Px activities as well as the T-AOC levels were significantly decreased in the SS group (p < 0.05). Moreover, there was a significant downregulation of hepatic SOD, GSH-Px, and GST genes in SS-exposed fish (p < 0.05). Interestingly, simultaneous dietary supplementation with SP provided a marked attenuation of the tissue antioxidative parameters when compared with the SS and control groups. To conclude, the present study exemplifies that dietary SP supplementation could be a beneficial abrogation of SS-induced tissue oxidative stress in the exposed fish.