Dry outer onion leaves resulting from the industrial processing of onions are currently discarded as agricultural waste, although some studies have demonstrated that onion peel has beneficial biological effects. Considering the traditional applications of onion peel, the present study evaluated comparatively the chemical and biological characteristics of four types of onion peel extracts, utilizing methanol, ethanol, acetone, or ethyl acetate as the extracting solvent. The extracts were analyzed for their chemical composition, antioxidant potential, and antimicrobial activity. The chemical analysis by UHPLC-DAD-ESI/MS identified 23 compounds in the extracts, belonging to phenolic acids and flavonoids. Quercetin was the main compound in all extracts, ranging in concentrations from 14.91 mg/g DW in the ethanol extract to 48.53 mg/g DW in the methanol extract. The highest contents of total phenols and flavonoids were found in the acetone extract, and the methanol extract demonstrated the highest antioxidant activity in DPPH and ABTS assays. The antimicrobial potential of the extracts was screened using a microdilution method against a spectrum of gastrointestinal microorganisms. The results revealed that all four extracts have significant antimicrobial potential against the tested microorganisms, of which the ethanol extract demonstrated the highest antimicrobial potency.

The oil extracted from hemp seeds has significant nutritional and biological properties due to the unique composition of polyunsaturated fatty acids and various antioxidant compounds. The potential of this oil for the prevention of oxidative stress and for the treatment of oxidative-stress-induced ailments is of increasing interest. Most studies of hemp seed oil were conducted in-vitro, meaning we lack information about effects and activity in vivo. In the present study, we evaluated the hypothesis that hemp seed oil at different concentrations improves the oxidative state of D. melanogaster, under non-stress as well as hydrogen-peroxide-induced stress. We analyzed the effects of hemp seed oil on oxidative stress markers and on the life cycle of D.melanogaster under non-stress and hydrogen-peroxide-induced stress conditions. D.melanogaster larvae were exposed to hemp seed oil concentrations ranging from 12.5 to 125 μL/mL. The results revealed that under non-stress conditions, oil concentrations up to 62.5 µL/mL did not induce negative effects on the life cycle of D. melanogaster and maintained the redox status of the larval cells at similar levels to the control level. Under oxidative stress conditions, biochemical parameters were significantly affected and only two oil concentrations, 18.7 and 31.2 µL/mL, provided protection against hydrogen peroxide stress effects. A higher oil concentration (125 μL/mL) exerted negative effects on the oxidative status and increased larval mortality. The tested oil was characterized chemically by NMR, transesterification, and silylation, followed by GC-MS analyses, and was shown to contain polyunsaturated fatty acid triglycerides and low levels of tocopherols. The high levels of linoleic and linolenic acids in the oil are suggested to be responsible for the observed in vivo antioxidant effects. Taken together, the results show that hemp seed oil is effective for reducing oxidative stress at the cellular level, thus supporting the hypothesis. The obtained results point to the potential of hemp seed oil for the prevention and treatment of conditions caused by the action of reactive oxygen species.

The aim of this work was to give as much information as possible on Rosa canina dried fruit that is commercially available in Serbia. In order to provide the chemical composition, the UHPLC-DAD-ESI-MS method was employed for both polar and non-polar extracts of samples obtained with a solvent mixture consisting of hexane, acetone, and ethanol in a volume ratio of 2:1:1, respectively, and 0.05% (w/v) butylated hydroxytoluene. In addition, the total content levels of lycopene, β-carotene, total polyphenols, and flavonoids were determined by means of UV-vis spectrophotometry. The antioxidant activity was tested by applying four different methods: ABTS, DPPH, FRAP, and CUPRAC. Overall, nine compounds were identified. The results of chemical composition analysis were used as the basis for the interpretation of the calculated results for the antioxidant and antimicrobial activity. The obtained results for R. canina dried fruit extract are as follows: β-carotene—7.25 [mg/100 g fruit weight]; lycopene—2.34 (mg/100 g FW); total polyphenol content (TPC)—2980 [mg GAE/kg FW]; total flavonoid content (TFC)—1454 [mg CE/kg FW]; antioxidant activity—ABTS 12.3 [μmol/100 g FW], DPPH 6.84, FRAP 52.04, and CUPRAC 15,425; and antimicrobial activity—Staphylococcus aureus MIC/MMC 4/0 [mg∙mL⁻¹], Enterococcus faecalis 4/0, Bacillus cereus 4/0, Escherichia coli 4/0, Salmonella enteritidis 4/4, Enteroabacter aerogenes 4/0, Pseudomonas aeruginosa 2/0, and Candida albicans 2/0.

This study aimed to evaluate the spasmolytic activity of an underground parts extract of Gentiana asclepiadea L. (Gentianaceae), assess its antioxidant and antimicrobial activities, and explore the impact of extract encapsulation on the aforementioned bioactivities. An extract encapsulated by spray drying with whey protein, pure extract, and pure whey protein were comparatively tested. The main compounds identified via HPLC-DAD analysis underwent in silico ADME assessment. The spasmolytic effect was tested on a model of spontaneous rat ileum contractions, and the mechanism of action was further evaluated on acetylcholine-, KCl-, CaCl₂-, BaCl₂-, histamine-, N(ω)-nitro-L-arginine methyl ester-, and glibenclamide-modified contractions. The most abundant compounds were secoiridoids (dominantly gentiopicroside), followed by C-glycosylated flavonoids and xanthones. Both pure and encapsulated extracts achieved significant spasmolytic effects, despite the spasmogenic activity of pure whey protein. The extract may exert its spasmolytic effect through multiple pathways, predominantly by antagonizing the Ca²⁺ channel and opening the K⁺ channel, while the nitric oxide pathway appears not to be involved. The antimicrobial and antioxidant activities of the pure extract were moderate. The extract stabilized by encapsulation retained all of the tested bioactivities of the unencapsulated extract. The obtained results suggest that G. asclepiadea has potential for use in the treatment of some gastrointestinal complaints and that the encapsulated extract could be a valuable functional ingredient in pharmaceutical and food products.

Eleven new and three reported half-sandwich Ru(II) arene complexes were synthesized using [Ru(η⁶-benzene)Cl(μ-Cl)]₂ and [Ru(η⁶-toluene)Cl(μ-Cl)]₂ and four pyridine carboxylic acid-based ligands (dicarboxylic acids and halogen derivatives). The structures and purity of synthesized compounds were confirmed using ¹H and ¹³C NMR spectroscopy, infrared spectroscopy, mass spectrometry, and elemental analysis. The stability of synthesized compounds in dimethyl sulfoxide solution was confirmed using ¹H NMR spectroscopy. The seven ligands, two complex precursors (CP1 and CP2), and 14 half-sandwich Ru(II) picolinate complexes (C1–C14) were evaluated for in vitro antibacterial and antifungal activity against pathogens, such as Staphylococcus aureus, Bacillus cereus, Proteus mirabilis, Klebsiella pneumoniae, Ecsherichia coli, Pseudomonas aeruginosa, Salmonella enteritidis, Enterobacter aerogenes, and yeast Candida albicans, using the microwell-dilution method. Among the tested samples, the ligands showed better inhibitory effect against Gram-positive bacteria when compared to the metal complexes. The most susceptible Gram-negative bacteria was Ecsherichia coli, with a MIC value of 1.25 mg/mL, for C3, C6, and C10. All synthesized complexes showed similar, slightly better activity against Candida albicans. Graphical Abstract