Inclusion complex of Callistemon viminalis essential oil prepared by kneading

Integrating diverse plant bioactive ingredients with cyclodextrins to fabricate functional films for food application: a critical review

The popularity of plant bioactive ingredients has become increasingly apparent in the food industry. However, these plant bioactive ingredients have many deficiencies, including low water solubility, poor stability, and unacceptable odor. Cyclodextrins (CDs), as cyclic molecules, have been extensively studied as superb vehicles of plant bioactive ingredients. These CD inclusion compounds could be added into various film matrices to fabricate bioactive food packaging materials. Therefore, in the present review, we summarized the extraction methods of plant bioactive ingredients, the addition of these CD inclusion compounds into thin-film materials, and their applications in food packaging. Furthermore, the release model and mechanism of active film materials based on various plant bioactive ingredients with CDs were highlighted. Finally, the current challenges and new opportunities based on these film materials have been discussed.

Antibacterial and Antifungal Activities and Toxicity of the Essential Oil from Callistemon viminalis Complexed with β-Cyclodextrin

The essential oil from Callistemon viminalis (EOC) is rich in monoterpenes, with a variety of biological properties: antibacterial, antifungal, insecticide, and antioxidant. Inclusion complexes (ICs) with cyclodextrins (CDs) is an alternative to prevent toxicity, improve the activity, and reduce the concentration to be used. Thus, the objective of this work was to prepare an IC (EOC/β-CD) and evaluate the antibacterial, antifungal and phospholipase activities, as well as the toxicity. Antimicrobial activity used the agar diffusion test and antifungal activity the disc diffusion test. Toxicity tests were carried out using Lactuca sativa L. The inhibition of phospholipase activity using the venom of Bothrops atrox as an inducer was performed. Antibacterial and antifungal tests demonstrated a decrease in the minimum inhibitory concentration (MIC) of the IC. It was most significantly observed for the bacterium Listeria monocytogenes, for which there was a decrease in the MIC from 250 µg mL^-1 to 62.5 µg mL^-1 after complexation, and for the fungus Aspergillus flavus, with a decrease in MIC from 125 µg mL^-1 to 62.5 µg mL^-1 after complexation. Toxicity tests with Lactuca sativa showed a decrease in toxicity after complexation in all parameters analyzed, with no statistical difference from the negative control. Inhibition of phospholipase activity induced by Bothrops atrox venom was more expressive in the highest proportion studied (1:10 m:m), exerting 23% inhibition. The assays demonstrated that the complexation between the EOC and β-CD is a promising alternative for use in different branches, especially in food industry, to fully exploit its application potential.

Preparation and characterization of a synthetic curcumin analog inclusion complex and preliminary evaluation of in vitro antileishmanial activity

The aim of this work was to prepare and characterize inclusion complexes between a synthetic curcumin analog (dibenzalacetone, DBA) and beta-cyclodextrin (β-CD); and to evaluate their in vitro antileishmanial activity. DBA was synthetized and characterized by spectroscopic methods and the inclusion complexes were obtained by kneading and lyophilization (LIO) in 1:1 and 1:2 stoichiometries. Phase solubility and dissolution assays showed a 40-fold increase in the aqueous solubility of DBA and its complete dissolution from LIO 1:1 formulation after 120 min respectively. Solid-state characterization by differential scanning calorimetry and near infrared spectroscopy demonstrated the inclusion of DBA in the β-CD cavity at the molar ratios tested, with LIO 1:1 formulation being the most stable. Using nuclear magnetic resonance experiments, the protons inside the cavity of β-CD were the most affected after the inclusion of DBA molecule. The cellular viability of THP-1 macrophage cells treated with plain DBA, β-CD and DBA/CD inclusion complexes showed that the plain DBA and DBA/CD at 1:2 stoichiometry presented toxicity, while β-CD alone and DBA/CD at 1:1 stoichiometry showed no toxicity up to 640 μg mL^-1. The in vitro assay with free-living promastigotes demonstrated that plain DBA and β-CD had IC₅₀ of < 10 and > 320 μg mL^-1 respectively, while only inclusion complexes with 1:1 stoichiometry showed antiproliferative activity with IC₅₀ = 51.3 μg mL^-1. Using the amastigote intracellular forms, there was also a difference between the plain and β-CD complexed DBA with complexes of 1:1 and 1:2 stoichiometry presenting EC₅₀ = 66.3 μg mL^-1 and 58.9 μg mL^-1 respectively. The study concluded that DBA/CD at 1:1 molar ratio has the potential to decrease the intrinsic toxicity of plain DBA towards Leishmania host cells, which may be a therapeutic advantage in the application of these compounds.