Avaliação da Toxicidade e efeito protetor de curcumina nanoencapsulada em Drosophila melanogaster

Abstract

Oxidative stress and inflammatory processes are induced by some diseases and toxic agents. Therefore, knowledge of compounds that have an effect on these markers may be an alternative for treating already established and untreated diseases. In this sense, curcumin deserves attention, a bioactive compound with a large presence of polyphenolic substances that give it antioxidant properties. Despite its properties, free curcumin can have toxic effects. In this context, nanoparticles are considered a promising strategy to reduce toxicity. The study aims to investigate a possible toxic effect of chronic exposure of Drosophila melanogaster to curcumin-loaded nanocapsules and evaluate their protective effect on toxicity induced by lipopolysaccharide (LPS). To verify whether or not the nanoencapsulation of curcumin in polysorbate 80 (p80) presents toxicity, and whether it enhances the pharmacological efficiency of this polyphenol. For this, D. melanogaster divided into groups of different concentrations of free curcumin and curcumin-loaded nanocapsules exposed for 10 days and evaluated for survival percentage. At the end, behavioral tests, acetylcholinesterase (AChE) activity, diet consumption, and oxidative stress parameters were carried out. It was observed that exposure to free curcumin and curcumin-loaded nanocapsules coated with P80, at the concentrations evaluated, did not cause toxic effects in D. melanogaster, and that with low doses it is already possible to positively modulate the markers evaluated. In the parameters addressed in the manuscript, regarding the evaluation of the protective effect of curcumin-loaded nanocapsules, it was seen that the concentration of 10 µM protected against changes in the behavioral and molecular profile induced by LPS in D. melanogaster, through the regulation of the p38 MAPK/Nrf2 pathways. We can suggest that nanoencapsulation of curcumin in p80 positively potentiated its antioxidant effects by regulating redox and antiapoptotic balance, suggesting that this mechanism of action can be explored in possible future applications in the treatment of diseases and toxic agents that act through a similar mechanism.