Antimicrobial and Antioxidant Efficacy of the Lipophilic Extract of Cirsium vulgare.

The aim of this study was to investigate the compounds in the hexane extract of Cirsium vulgare (Savi.) Ten. and to determine the antibacterial, antifungal, and antioxidant activities of different extracts. The Cirsium vulgare (NGBB 7229) plant was collected from Turkey's Trakya region. Crude extracts were obtained using different solvents. The chemical composition of Cirsium vulgare was determined in hexane extract using gas chromatography mass spectrometry. The antioxidant activities of the extracts were evaluated by Trolox equivalent antioxidant activity (TEAC), ferric-reducing antioxidant power (FRAP), cupric-reducing antioxidant capacity (CUPRAC), the ß-carotene bleaching method, and the determination of superoxide anion scavenging activities. The antibacterial activity was tested against Staphylococcus aureus, Bacillus subtilis, Escherichia coli, Pseudomonas aeruginosa, Proteus mirabilis, and Salmonella typhimurium, whereas the antifungal activity was tested against Candida albicans, Candida glabrata, Candida parapsilosis, Candida krusei, Penicillium chrysogenum, and Aspergillus fumigatus by applying microdilution methods. A total of 41 bioactive compounds were identified using the GC-MS library. Terpenoids were found to be dominant (52.89%), and lup-20(29)-en-3-yl-acetate and lupeol were the most abundant terpenoids. The highest total flavonoid content (25.73 mg catechin/g) and antioxidant capacity were found in the methanolic extract. The highest antibacterial activity was detected against Bacillus subtilis in the ethyl acetate extract, and the highest antifungal activity was found against Candida krusei and Aspergillus fumigatus in the hexane extract. The observed antioxidant characteristics of the C. vulgare extracts could be attributed to the presence of flavonoids. The high antifungal activity of the hexane extract against all fungal strains can be attributed to its constituents, i.e., terpenoids. This study discloses the potential antioxidant and antimicrobial activities, including some bioactive components, of Cirsium vulgare and implies that Cirsium vulgare holds possible applications in the food and pharmaceutical industries as an antioxidant, antibacterial, and antifungal agent.

Genotype-Related Differences in the Phenolic Compound Profile and Antioxidant Activity of Extracts from Olive (Olea europaea L.) Leaves.

The phenolic compound contents and antioxidant activities of the leaf extracts of nine olive genotypes were determined, and the obtained data were analysed using chemometric techniques. In the crude extracts, 12 compounds belonging to the secoiridoids, phenylethanoids, and flavonoids were identified. Oleuropein was the primary component for all genotypes, exhibiting a content of 21.0 to 98.0 mg/g extract. Hydroxytyrosol, verbascoside, luteolin 7-O-glucoside, and luteolin 4'-O-glucoside were also present in noticeable quantities. Genotypes differed to the greatest extent in the content of verbascoside (0.45⁻21.07 mg/g extract). The content of hydroxytyrosol ranged from 1.33 to 4.03 mg/g extract, and the aforementioned luteolin glucosides were present at 1.58⁻8.67 mg/g extract. The total phenolic content (TPC), DPPH• and ABTS•+ scavenging activities, ferric reducing antioxidant power (FRAP), and ability to inhibit the oxidation of -carotene-linoleic acid emulsion also varied significantly among genotypes. A hierarchical cluster analysis enabled the division of genotypes into three clusters with similarity above 60% in each group. GGE biplot analysis showed olive genotypes variability with respect to phenolic compound contents and antioxidant activities. Significant correlations among TPC, FRAP, the values of both radical scavenging assays, and the content of oleuropein were found. The contents of 7-O-glucoside and 4'-O-glucoside correlated with TPC, TEAC, FRAP, and the results of the emulsion oxidation assay.