Zearalenone-Induced Toxicity and the Ameliorative Role of Silicate in Nile Tilapia ( <i>Oreochromis niloticus</i> ): Evaluation of Growth, Feed Efficiency, Oxidative Stress, and Related Gene Markers

Abstract

Abstract Zearalenone (ZEA) contamination in aquafeeds poses a significant risk to the health and productivity of aquatic organisms, necessitating strategies to mitigate its toxic effects. The present study investigated the toxicological effects of dietary ZEA and evaluated the ameliorative potential of sodium metasilicate supplementation in Nile tilapia ( Oreochromis niloticus ; weight =19.98 ± 0.19 g) during a 75-day feeding trial. Four experimental diets were formulated: a control diet without additives (D1), a diet supplemented with ZEA at 1 mg/kg (D2), a diet containing sodium metasilicate at 0.5 g/kg (D3), and a combined diet with both ZEA and sodium metasilicate (D4). The results indicated that exposure to ZEA (D2) significantly ( P &lt; 0.05) reduced growth performance and feed utilization efficiency, increased hepatic enzyme activities (ALT and AST), reduced total protein and globulin levels, and disrupted lipid metabolism. ZEA markedly ( P &lt; 0.05) suppressed serum immunoglobulin M (IgM), total antioxidant capacity (TAC), and glutathione peroxidase (GPx), while increasing malondialdehyde (MDA) levels. ZEA significantly ( P &lt; 0.05) downregulated hepatic expression of genes associated with growth ( GHR , IGF ), antioxidant defense ( GPx , CAT ), and immune function ( LYZ , C3 ). In contrast, silicate supplementation (D3) improved growth indices, enhanced antioxidant and immune responses, and upregulated the aforementioned genes. The combined treatment group (D4) exhibited partial mitigation of ZEA-induced effects. These findings suggest that sodium metasilicate supplementation effectively counteracts ZEA-induced physiological, biochemical, and molecular impairments in Nile tilapia, thereby enhancing fish health and performance. This study highlights the potential of sodium metasilicate as a dietary detoxifying agent to safeguard aquaculture species against the adverse effects of feed-borne mycotoxins such as ZEA. Future studies should optimize silicate dosage, test its efficacy across mycotoxins and species, verify mechanisms through transcriptomic and proteomic analyses, and specifically address ZEA’s reproductive effects to determine whether sodium metasilicate supplementation can also protect endocrine function.