Supramolecular complexes between Plinia cauliflora (DC.) Kausel extracts and β-cyclodextrin: Physicochemical characterization and antioxidant and anti-inflammatory properties

Abstract

This work aims to investigate the supramolecular complexes formation between β-cyclodextrin (βCD) and compounds present in leaves (EEL) and branches (EEB) of Plinia cauliflora (DC.) Kausel Physicochemical characterization was carried out to investigate the formation of supramolecular complexes (EEL/βCD and EEB/βCD), such as, Fourier-transform infrared (FTIR) spectroscopy, thermal analysis (TGA/DTA), scanning electron microscopy (SEM), dynamic light scattering (DLS), Zeta potential (ZP), and electrical conductivity measurements. Antioxidant activity was evaluated by the 2,2-diphenyl-1-picrylhydrazyl, β-carotene/linoleic acid, and thiobarbituric acid reactive substance assays. Finally, anti-inflammatory activity was investigated by nitric oxide (NO) determination and evaluation of ear edema inhibition. FTIR spectroscopy and TGA/DTA confirmed the interactions in the solid-state, while ZP and DLS showed that the interaction between extracts and βCD caused differences in the hydrophobic nanoprecipitates. Moreover, the SEM micrograph of EEL/βCD and EEB/βCD indicates changing in particle morphology which confirms the interactions between extract compounds and βCD. EEL/βCD and EEB/βCD showed promising antioxidant activity for all assays performed. Furthermore, anti-inflammatory activity was confirmed by a significant reduction of NO (maximum of 90 and 85% for EEL/βCD and EEB/βCD, respectively) and inhibition of ear edema above 93% for both phytocomplexes. The development of a formulation based on the molecular encapsulation of extracts from P. cauliflora with βCD could be an effective, safe, and sustainable therapeutic alternative. Therefore, our samples showed the ability to reduce oxidative stress and inflammation, and serve as potential anti-inflammatory agents.