Desenvolvimento de nanoformulação de zeína para liberação controlada de apocinina

Abstract

Apocynin (APO) is a phenolic compound initially isolated from the species Picrorhiza kurroa. This compound has been extensively investigated for its ability to inhibit the nicotinamide adenine dinucleotide phosphate (NADPH) multi-enzymatic complex by interacting with the activating proteins necessary to assemble the enzyme units and, consequently, blocking its activity. This complex is the only endogenous system intended for superoxide anion production, a precursor of highly oxidizing substances. In this sense, a biological action of apocynin consists of modulating the action of NADPH oxidase and preventing the formation of oxidative species that, in excess, can modify the redox state of cells. As a result, APO has a positive effect on the prevention and remediation of a wide number of diseases including ischemic accidents, Alzheimer's, diabetes and others. However, APO presents some options for using it in terms of pharmacokinetic properties, mainly due to the oral route, which result in low absorption and rapid elimination of the compound. The nanostructured systems based on naturals polymers have been a promising way to improve the physicochemical characteristics of various compounds. In this context, the objective of the present study was to develop a zein, casein and lysine nanoparticle (NP-ZCL-APO) using the liquid-liquid dispersion method to enable APO by oral route. The nanoparticles obtained were characterized by particle size distribuition, mean particle size (𝑆̅), polydispersity index (PI), zeta potential (ZP), encapsulation efficiency (% EE), scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), thermal analysis (TA), simulated gastrointestinal release, stability assessment, hemolytic cytotoxicity and cytotoxicity against Vero, Caco-2, and HaCaT cells. The 𝑆̅value was 208.8 ± 12.3 nm, with PI of 0.134 ± 0.036, and ZP of -22.0 ± 2.3 mV. SEM images demonstrated regular and spherical shape. The % EE was optimized which resulted in 27.1 ± 3.5 % encapsulation, (1.91 ± 0.26 mg APO / mL).There was no evidence of chemical reactions and formation of new components in the matrix from FTIR. NP-ZCL-APO showed an increase in thermal stability, a reduction in blood cell toxicity that causes cell disruption and reduced inhibition of normal cell growth when compared to free APO. The APO cumulative gastrointestinal release was 31.2 ± 2.1 %. Regarding stability, NP-ZCL-APO maintained the physicochemical characteristics after the freeze-drying process with cryoprotectant and also when it was subject to storage at refrigerated temperature (4 °C) and room temperature (25 °C) for a period of ten months. In addition, there was a reduction in toxicity on blood cells and on normal cells when compared to free APO. In addition, NP-ZCL-APO showed interaction with mucin, the main glycoprotein in mucus, indicating mucoadhesion. Based on the characterizations set, combined with the low cost of formulation and low toxicity, the obtained system was consolidated for in vivo tests. The maintenance of the physicochemical characteristics after the freeze-drying process, in the presence of the selected cryoprotectant, is a result that favors this direction. Therefore, the study concluded the nanoparticle of NP-ZCL-APO developed is a potential alternative to optimize the pharmacokinetic properties and bioavailability of APO for the use of this compound orally.