Ecotoxicological impact of mosquitocidal jasmine-based oils nanoemulsion on Nile tilapia fish Oreochromis niloticus.

Nanoemulsion technology has become a promising approach for improving stability and bioavailability of natural products, providing more efficient and eco-friendly biocides. Jasmine oil, derived from Jasminum spp., represents a natural product with mosquitocidal properties. This study investigated the potential pathophysiological effects of jasmine oil nanoemulsion (JA-NE) on Nile tilapia (Oreochromis niloticus), a species of economic importance in Egypt. The acute toxicity assessment indicated a 96-h LC₅₀ value above 100 mg/L, with no adverse effects observed at sublethal doses. However, chronic exposure at sublethal concentrations of 5 and 10 mg/L (5 and 10%) for 28 days revealed significant elevation in hepatic enzymes (AST, ALT) and creatinine, indicating potential liver and kidney stress. Lipid peroxidation and antioxidant responses were also emphasized by a significant increase in oxidative stress biomarkers, particularly malondialdehyde (MDA), and mixed responses of glutathione (GSH) and glutathione-S-transferase (GST) levels. Additionally, immune functions were altered where proinflammatory cytokines, interleukin-1β (IL-1β) and tumor necrosis factor (TNF-α), exhibited concentration-dependent changes. Histopathological analysis revealed tissue damage in gills, liver, kidneys, and brain, showing lamellar fusion, hepatocyte vacuolation, and renal tubular necrosis. In conclusion, although JA-NE exhibited low acute toxicity, but its prolonged exposure to sublethal doses can induce physiological risks to aquatic organisms. Such findings underscore the need for careful consideration of dosage and exposure duration of nanoemulsions to balance their benefits versus their potential aquatic ecosystem impacts.