Complexos de inclusão do óleo de Euterpe oleracea Mart. em (B-) ou (HP-B-) ciclodextrinas e ação antioxidante, antiinflamatória e modulatória antibacteriana

Abstract

Euterpe oleracea Mart. (OEO), known as açaí oil, is commonly used by the food and cosmetics industry. The OEO presents important biological activities, however its use by the pharmaceutical industry is limited due to its physicochemical properties. Inclusion complexes have been used to increase solubility, stability and biological activities of vegetable oils. Therefore, the objective of this study was to obtain inclusion complexes with OEO in βcyclodextrin (OEO-β-CD) and hydroxypropyl-β-cyclodextrin (OEO-HP-β-CD), perform the physicochemical characterization of each product and test their antimicrobial, antioxidant and anti-inflammatory activity. The chemical characterization of the OEO was carried out by gas chromatography coupled to a flame ionization detector (CG-FID) and the interaction energy between oleic acid and cyclodextrins was determined. The complexes obtained through kneading (KND) and slurry (SL) were characterized by FTIR, MEV, DR-X, TG/DTG and DSC. The antibacterial activity expressed in Minimum Inhibitory Concentration (MIC) and the modulatory activity against drugs were evaluated against Staphylococcus aureus (ATCC 25932), Enterococcus faecales (ATCC 29212), Pseudomonas aeruginosa (ATCC 27853) and Escherichia coli (ATCC 25922), was evaluated (in vitro) and anti-inflammatory (models of paw edema and air sac) in Swiss mice. CG-FID presented oleic acid (47.58%) as the main constituent of the oil. Inclusion complexes with β-CD and HP-β-CD demonstrated encapsulation efficiency, with a better interaction energy between oleic acid and β-CD (-41.28 ± 0.57 kJ/mol). The results of the physical-chemical characterization showed complexation between OEO and both cyclodextrins and proposed preparation methods, without great variations. However, OEO-β-CD (KND) exhibited smaller mass loss and energy variation in ranges of 30-130ºC, related to the loss of water during their preparation, suggesting better complexation efficiency. MICs revealed that complexes improved OEO activity, especially OEO-β-CD (SL), against all the bacterial strains used. The modulatory response of OEO, OEO-β-CD (MX), OEO-β-CD (SL) and OEO-HP-β-CD (SL) showed a synergistic effect to ampicillin against E. coli, although they maintained biological activity of the other antibiotics. The OH- radical scavenging activity demonstrated synergism between CD and OEO with the use of OEO-HP-β-CD (MX), showing an increase of 437% in oil activity, while both complexes prepared by SL demonstrated enhancement of the reducing power activity by 208%. The treatment with OEO-β-CD (MX) reduced the paw edema by 200% and 112% of MPO activity. In an air bag model, this treatment showed a reduction in leukocyte, MPO and IL-1β indices, while glutathione and IL-10 were increased, demonstrating an enhancement of the anti-inflammatory effect of OEO. The pharmacological responses displayed by the complexes are highly relevant, since it supports studies for the development of new pharmaceutical formulations, as well as new dose-response and safety tests.