Stabilization of Black Locust Flower Extract via Encapsulation Using Alginate and Alginate-Chitosan Microparticles.

Black locust flower extract contains various polyphenols and their glucosides contribute to the potential health benefits. After intake of these bioactive compounds and passage through the gastrointestinal tract, their degradation can occur and lead to a loss of biological activity. To overcome this problem, the bioactive compounds should be protected from environmental conditions. This study aimed to encapsulate the black flower extract in the microparticles based on biodegradable polysaccharides, alginate, and chitosan. In the extract, the total antioxidant content was found to be 3.18 ± 0.01 g gallic acid equivalent per 100 g of dry weight. Also, the presence of lipids (16), phenolics (27), organic acids (4), L-aspartic acid derivative, questinol, gibberellic acid, sterol, and saponins (2) was confirmed using the UHPLC-ESI-MS analysis. In vitro assays showed that the extract has weak anti-α-glucosidase activity and moderate antioxidant and cytotoxic activity against the HeLa cell line. The extrusion method with secondary air flow enabled the preparation of microparticles (about 270 µm) encapsulated with extract. An encapsulation efficiency of over 92% was achieved in the alginate and alginate-chitosan microparticles. The swelling study confirmed a lower permeability of alginate-chitosan microparticles compared with alginate microparticles. For both types of microparticles, the release profile of antioxidants in the simulated gastrointestinal fluids at 37 °C followed the Korsmeyer-Peppas model. A lower diffusion coefficient than 0.5 indicated the simple Fick diffusion of antioxidants. The alginate-chitosan microparticles enabled a more sustained release of antioxidants from extract compared to the alginate microparticles. The obtained results indicated an improvement in the antioxidant activity of bioactive compounds from the extract and their protection from degradation in the simulated gastric conditions via encapsulation in the polymer matrixes. Alginate-chitosan showed slightly slower cumulative antioxidant release from microparticles and better antioxidant activity of the extract compared to the alginate system. According to these results, alginate-chitosan microparticles are more suitable for further application in the encapsulation of black locust flower extract. Also, the proposed polymer matrix as a drug delivery system is safe for human use due to its biodegradability and non-toxicity.

Optimization of Ultrasound-Assisted Extraction and Encapsulation of Antioxidants from Orange Peels in Alginate-Chitosan Microparticles.

The recovery of bioactive compounds from waste and modification of their properties by encapsulation are the main challenges today. In this study, the ultrasound-assisted extraction of antioxidants from orange peels was optimized using a central composite design. Ethanol (50%, v/v) was the solvent of choice for their extraction. The obtained total antioxidant contents were fitted using the second-order polynomial equation. The optimal conditions were the extraction time of 30 min, temperature of 60 °C, and the liquid-to-solid ratio of 15 mL/g. After that, the optimal extract was encapsulated in alginate-chitosan beads to modify the release of antioxidants under gastrointestinal tract conditions. The average size of beads was 252 µm, while the encapsulation efficiency was 89.2%. The results of the FTIR analysis indicated that there are no interactions between compounds of the extract and alginate-chitosan. In vitro release studies showed an initial rapid and then slow release of antioxidants. This release followed the simple Fickian diffusion. The encapsulation of orange peel extract provided improvement in the delivery of antioxidants after gastrointestinal digestion. The obtained encapsulated beads can be applied as the natural active ingredient of food, cosmetics, and pharmaceutical products.

Ultrasound-Assisted Extraction of Carotenoids from Orange Peel Using Olive Oil and Its Encapsulation in Ca-Alginate Beads.

The paper was aimed at developing an ultrasound-assisted extraction of carotenoids from orange peel using olive oil as a solvent. A central composite design was used to define the optimal conditions for their extraction. Under the optimal conditions (extraction time of 35 min, extraction temperature of 42 ℃, and a liquid-to-solid ratio of 15 mL/g), the experimental and predicted values of carotenoid content were 1.85 and 1.83 mg/100 g dry weight, respectively. The agreement of these values indicated the adequacy of the proposed regression model. The extraction temperature only had a negative influence on carotenoid content. The impact of extraction parameters on the carotenoid content was decreased according to the following order: extraction time, liquid-to-solid ratio, and extraction temperature. Ca-alginate beads were prepared using the extrusion process to increase the stability and protect the antioxidant activity of olive oil enriched with carotenoids. The encapsulation efficiency and particle mean diameter were 89.5% and 0.78 mm, respectively. The presence of oil extract in Ca-alginate beads was confirmed by Fourier-transform infrared spectroscopy. The antioxidant activity of the oil enriched with carotenoids before and after encapsulation in the alginate beads was determined according to the DPPH assay.

Optimization of ultrasound-assisted extraction of polyphenols from wheatgrass (Triticum aestivum L.).

Conventional extraction techniques require high consumption of available resources and thus are ineffective and expensive, especially at an industrial scale. The aim of the study was to optimize the ultrasound-assisted extraction of polyphenols from fresh wheatgrass (Triticum aestivum L.). The effects of different extraction techniques and solvents were investigated on the yield of extractive substances and antioxidant activity. The ultrasound-assisted extraction technique and ethanol gave the highest yield of extractive substances so that they were used in the optimization studies. The central composite design was employed to find the optimal levels of ethanol concentration, extraction temperature, and extraction time. The total phenolic content was varied in the range of 10.50-15.50 grams of gallic acid equivalents per 100 g of dry weight of plant material (g GAE 100 g-1 dw). The optimal conditions for ultrasound-assisted extraction were: (1) 56% (v/v) ethanol, (2) temperature of 59 °C, and (3) extraction time of 28 min. The results of ANOVA indicated that the highest impact had the extraction temperature on the total phenolic content. The toxic solvents were not used in the developed extraction procedure. The consumption of energy and raw plant material is estimated to be lower by at least 10% compared to conventional techniques.

Drug design strategies with metal-hydroxyquinoline complexes.

Introduction: 8-hydroxyquinoline derivatives and their complexes with transition metals are the subject of many studies due to their anticancer, anti-inflammatory, anti-infective, and antidiabetic activities.Areas covered: Within this article, the authors review the synthesis and current applications of metal-8-hydroxyquinoline complexes in drug design with a critical overview of the latest advancements in the field.Expert opinion: Metal-8-hydroxyquinoline complexes are especially interesting because of their simple synthesis procedures and possible applications in modern medicine. The complexation between transition metal ions and 8-hydroxyquinoline or its derivatives is achieved via their O and N atoms. The main problem with their application is lipophilicity. This particular property has an impact on their solubility, biological activity, transport through the cell membrane, construction of the complex with a receptor, and development of drugs. Furthermore, in the treatment of neurodegenerative diseases and brain cancers, the passage of the complexes through the blood-brain barrier can only be ensured through novel drug design.

Development and optimization of formulation for treatment of copper deficiency in human organism.

The aim of this study was to design and optimize a new tablet formulation for treatment of copper deficiency in human organism by using an experimental design. The new no-veneered tablets, prepared by a wet granulation technique, are containg active substance, a copper(II) complex with polysaccharide pullulan. The binder concentration, the disintegrant concentration and the resistance to crushing were used as independent variables in the formulation, while in vitro measured drug release characteristics of the tablets was response variable in a full factorial design 2(3) modeling. A cubic model for data fitted was used to examine the obtained results. They showed that the resistance to crushing has the most significant effect on copper(II) complex release from the formulation, while the disintegrant concentration has smaller influence on dissolution profile of copper(II) complex and the binder concentration had minor impact in this study. Lower value of resistance to crushing has influence on better dissolution profile. Furthermore, physical characteristics of the tablets were evaluated, viz., drug content, hardness, thickness, friability, disintegration time, mass variation, particle size and size distribution.