Nanoencapsulação de curcumina e avaliação in vitro da atividade das enzimas AchE, BchE e GST em tecidos biológicos de Drosophila melanogaster

Abstract

Curcumin (CUR) is the main bioactive polyphenolic compound present in curcuma rhizomes (Curcuma longa L.), and has characteristics already known as antioxidants, anti-inflammatory and neuroprotective. Its low bioavailability, water insolubility and instability limit its application, hindering its action and absorption in certain tissues. Several techniques can be used to improve the dissolution and bioavailability of poorly water-soluble bioactive, among which are solid dispersions. Objective of this study was to produce CUR nanoparticles encapsulated by Poly (ethylene glycol) 6000 (PEG) and Poloxamer 407 (P407) polymers and characterized by Transmission Electron Microscopy, Laser Diffraction, Differential Scanning Calorimetry, Infrared Spectrophotometry and X-ray diffraction. Its in vitro effects on glutathione S-transferase (GST), acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) activity of Drosophila melanogaster (DM) tissue were examined. Results showed nanoparticles with irregular shapes, with 50% of particles having diameters smaller than 0.937 ± 0.010 μm for both polymeric encapsulants used. Physicochemical characterization techniques showed that the CUR was effectively encapsulated, allowing the dissolution of CUR in phosphate buffer and water. CUR encapsulated in P407 modulated the activity of the AChE, BChE and GST enzymes with IC50 of 27.99 μM, 24.89 μM and 8.86 μM, respectively. When PEG was used as an encapsulant, CUR also modulated the enzymatic activity, but at higher concentrations. From this, it’s concluded that solid dispersion maintained the characteristics of the free CUR on the modulation in enzymes AChE, BChE and GST in vitro tests from the tissue of the DM, being indicative of the increase in its bioavailability.