Encapsulação de luteína e avaliação in vitro da atividade da enzima acetilcolinesterase

Abstract

The causes of Alzheimer’s (AD) disease have been the subject of intense investigation. At present, search by new medicine and treatments become important. This way, the lutein showed possible candidate to act as a medicine of AD, but, it instability the extern’s agents and it low solubility hamper its application, which can be bypassed with encapsulate techniques. The objective of this study was encapsulated lutein and assess their ability to act as inhibitory compound of AChE activity and determine it reaction kinetics. The method of solid dispersion was followed to obtain nanoparticles of polyvinylpyrrolidone containing lutein. For the characterization of the nanoparticles were performed the analyzes Differential Scanning Calorimetry (DSC), Fourier Transform Infrared (FTIR), X-ray Diffraction (DRX), Transmission Electron Microscopy (MET) and UV-Vis spectroscopy. Solution of lutein nanoparticles and pure in water and ethanol were test in vitro as AChE inhibitor by a method based on UV-Vis absorbance. The kinetic parameters (Michaelis-Menten constant (Km) and maximum velocity (Vmax)) were determined analysis of the enzymatic activity in water for lutein encapsulated a pure. The characterization showed the nanoparticles have spherical morphology and approximate diameter of the 200 nm, it was possible to demonstrated the effective encapsulation of lutein by PVP. The biologic tests the concentrations of 200 µM and 300 µM for the lutein pure and particles in water showed significantly differed of control. The kinetics analyses showed mixed-type inhibition by lutein encapsulated and pure with values of Ki of 265,4 µM and 261,6 µM, respectively. Therefore, were possible encapsulated lutein by the method of solid dispersion, and the lutein pure and encapsulate showed inhibition of the AChE activity.