Hydroxypropyl-β-Cyclodextrin-Based Helichrysum italicum Extracts: Antioxidant and Cosmeceutical Activity and Biocompatibility

Improved Kaempferol Solubility via Heptakis-O-(2-hydroxypropyl)-β-cyclodextrin Complexation: A Combined Spectroscopic and Theoretical Study

Four cyclodextrins (CDs) including heptakis-O-(2-hydroxypropyl)-β-cyclodextrin (HP-β-CD), heptakis-O-(2,6-di-O-methyl)-β-cyclodextrin (DM-β-CD), β-cyclodextrin (β-CD), and γ-cyclodextrin (γ-CD) were evaluated for their ability to enhance the aqueous solubility of kaempferol (Kae). Phase solubility studies indicated that these four CDs can form 1:1 type complexes with Kae and that HP-β-CD demonstrated the most significant solubilizing effect on Kae. Among the CDs tested, HP-β-CD demonstrated the most significant solubilizing effect on Kae. With an HP-β-CD concentration of 5.00 × 10-3 mol·L-1, the concentration of Kae reached 4.56 × 10-5 mol·L-1, which is 12.7 times greater than its solubility in water. Characterization of the HP-β-CD/Kae complex was performed using empirical methods. Molecular docking indicated that the A and C rings of Kae fit into the hydrophobic cavity of HP-β-CD, while the B ring remained at the rim. Six hydrogen bonds were found between HP-β-CD and the -OH groups of Kae. The negative complexation energy (ΔE) suggests the complex formation was exergonic. A 30-ns molecular dynamics simulation revealed no significant structural changes, with average root-mean-square deviation RMSD values of 2.230 Å for HP-β-CD and 0.786 Å for Kae, indicating high stability of the complex.

Enhancement of the biological activity of hydroxytyrosol through its oxidation by laccase from Trametes versicolor

The laccase-catalyzed oxidation of hydroxytyrosol (HT) towards the formation of its bioactive oligomer derivatives was investigated. The biocatalytic oligomerization was catalyzed by laccase from Trametes versicolor in aqueous or various water-miscible organic solvents and deep eutectic solvent (DES)-based media. Mass Spectroscopy and Nuclear Magnetic Resonance were used for the characterization of the products. The solvent system used significantly affects the degree of HT oligomerization. The use of 50 % v/v methanol favored the production of the HT dimer, while other organic solvents as well as DESs led to the formation of hydroxytyrosol trimer and other oligomers. In vitro studies showed that the HT dimer exhibits 3- to 4-fold enhanced antibacterial activity against Gram-positive and Gram-negative bacteria compared to the parent compound. Moreover, the ability of HT dimer to inhibit the activity of soybean lipoxygenase and Candida rugosa lipase was 1.5-fold higher than HT, while molecular docking supported these results. Furthermore, HT dimer showed reduced cytotoxicity against HEK293 cells and exhibited a strong ability to inhibit ROS formation. The enhanced bioactivity of HT dimer indicates that this compound could be considered for use in cosmetics, skin-care products, and nutraceuticals.

Wound healing potential of extract from Sambucus nigra L. leaves and its fractions

ETHNOPHARMACOLOGICAL RELEVANCE

Sambucus nigra L. (Viburnaceae), commonly known as black elderberry, is a native species throughout Europe and Western Asia. Elderberry leaves have been used in traditional European medicine, mainly externally, to treat skin and mucosal diseases. They are usually used as decoctions for washing hemorrhoids, ulcers, insect bites, wounds, scrapes, and gingivitis.

AIM OF THE STUDY

Our work aimed to scientifically verify the traditional use of the plant material in treating wounds and skin inflammations accompanied by its phytochemical characterization.

MATERIALS AND METHODS

The effect of 70% (v/v) ethanolic extract and its fractions of different polarities on the inflammatory response of cells involved in wound healing (fibroblasts, keratinocytes, and neutrophils) was investigated. In addition, their effect on the migration of keratinocytes to the scratch site in an in vitro wound healing assay and their impact on the activity of the enzymes involved in skin inflammation, were assessed. The chemical composition was analyzed by UHPLC-DAD-MSn, and the structure of the isolated compounds was determined by NMR.

RESULTS

The supportive effect of the elderberry leaves extract towards wound healing and modulation of the inflammatory response was demonstrated by induction of the keratinocytes. Additionally, the extract was shown to affect the cellular secretion of TNF-α and interleukins -1β, -6, and -8. Examinations of fractionated extract have shown that active principles were mainly contained in dichloromethane fraction. Eleven chemical constituents belonging to flavonoids, cyanogenic glycosides, and lignans were isolated and characterized.

CONCLUSION

The beneficial effect of S. nigra leaves in treating skin diseases has been partially verified and supports its traditional use in skin ailments of different etiologies.

Bioactive Peptides and Protein Hydrolysates as Lipoxygenase Inhibitors

Lipoxygenases are non-heme iron-containing enzymes that catalyze the oxidation of polyunsaturated fatty acids, resulting in the production of lipid hydroperoxides, which are precursors of inflammatory lipid mediators. These enzymes are widely distributed in humans, other eukaryotes, and cyanobacteria. Lipoxygenases hold promise as therapeutic targets for several human diseases, including cancer and inflammation-related disorders. Inhibitors of lipoxygenase have potential applications in pharmaceuticals, cosmetics, and food. Bioactive peptides are short amino acid sequences embedded within parent proteins, which can be released by enzymatic hydrolysis, microbial fermentation, and gastrointestinal digestion. A wide variety of bioactivities have been documented for protein hydrolysates and peptides derived from different biological sources. Recent findings indicate that protein hydrolysates and peptides derived from both edible and non-edible bioresources can act as lipoxygenase inhibitors. This review aims to provide an overview of the current knowledge regarding the production of anti-lipoxygenase protein hydrolysates and peptides from millet grains, chia seeds, insects, milk proteins, fish feed, velvet antler blood, fish scales, and feather keratins. The anti-lipoxygenase activities and modes of action of these protein hydrolysates and peptides are discussed. The strengths and shortcomings of previous research in this area are emphasized. Additionally, potential research directions and areas for improvement are suggested to accelerate the discovery of anti-lipoxygenase peptides in the near future.