Avaliação da toxicidade e do potencial antioxidante de nanopartículas contendo extrato de compostos fenólicos de melão Cantaloupe (Cucumis melo L.) em peixe-zebra (Danio rerio)

Abstract

Phenolic compounds (PCs) have antioxidant effects but are sensitive to environmental conditions, compromising their functionality. Nanoencapsulation aims to increase the stability and bioactive potentiation of these compounds. Toxicological investigation of plant extracts and new materials is crucial and should precede the evaluation of functional properties to minimize harmful effects. This study evaluated the toxicity and antioxidant potential of the crude extract of phenolic compounds from Cantaloupe melon (free - CEPC and nanoencapsulated - EPWC) in zebrafish. Encapsulation was performed by nanoprecipitation in anti-solvent (acetone), using concentrated whey protein (1 crude extract: 4 encapsulating agent w/w) and Tween 80. Acute toxicological screening was performed in zebrafish's embryonic and adult phases exposed for 96h to concentrations (25–400 mg/L) of CEPC and EPWC. The antioxidant potential in the brains of adult animals was also evaluated. CEPC and EPWC showed 50% inhibitory activity (IC50) of the ABTS+ radical at 1.64 (0.14) and 1.10 (0.02) mg/mL, respectively, suggesting the potentiation of the antioxidant activity in EPWC (7-fold). For embryos, the estimated median lethal concentration (LC50) of CEPC and EPWC was 231.2 (35.9) mg/L and 233.8 (25.4) mg/L, respectively. For adult fish, it was impossible to estimate the LC50. However, sublethal signals were evidenced at concentrations ≥ 100 mg/L. The neurobehavioral evaluation showed that anxiety-like behavior may have been bidirectionally modulated, where lower and higher concentrations may be indicative of an anxiogenic effect or even nullify the anxiolytic effect promoted by median concentrations. The evaluation of reactive oxygen species (ROS) in the brains of the animals indicated a significant reduction of free radicals in the EPWC group compared to the control (p < 0.05). The results suggest the safe application of CEPC and EPWC at concentrations < 100 mg/L, with additional redox modulation observed for EPWC. The antioxidant potential of EPWC deserves further investigation regarding the underlying mechanisms and long-term impacts.