Produção e caracterização de nanopartículas de betacaroteno e análise in vitro da modulação da atividade enzimática em moscas da espécie Drosophila melanogaster

Abstract

Betacarotene is a carotenoid precursor of vitamin A, known by its biological activity such as the ability to reduce cell oxidative stress. Since betacarotene is highly hydrophobic, its transformation in nanoparticles, also called nanonization, may be a promising alternative to improve its water affinity and thus its activity in aqueous systems. The aim of this work was to produce betacarotene nanoparticles by solid dispersion method, carry out their characterization and to evaluate its modulation on biological activities of enzymes acetylcholinesterase (AChE) and glutathione S-transferase (GST) through in vitro assays using Drosophila melanogaster tissue as source of the enzymes mentioned above. AChE is related to like Alzheimer´ disease and cognitive functions and GST is related to cell oxidative stress. Transmission Electronic Microscopy and Dynamic Light Scattering were performed to evaluate the morphology of the nanoparticles. Differential Scanning Calorimeter was used to analyze thermal behavior of pristine and nanoparticulated betacarotene. X-Ray diffraction was used to observe crystallinity and Fourier Transformed Infrared to evaluate chemical interactions between the compounds of the nanoparticles. Gathered results showed that nanometric betacarotene crystals formed were colloidally stable in water and there was not any chemical interaction between betacarotene and polyvinylpyrrolidone. Also, nanonization process did not affect crystalline structure of betacarotene. When dispersed in water, the nanoparticles were able to modulate the action of GST, causing an increase in the enzyme activity in lower concentrations and a decrease in the activity of the enzyme for higher concentrations. Moreover, the nanoparticles caused a decrease of the enzyme activity of AChE in lower concentrations when compared to pristine betacarotene in water.