The antioxidative and antimicrobial activity of the aqueous earth smoke (Fumaria officinalis L.): Extract

Earth smoke herb (Fumaria officinalis L.) was used as a source of extractive mat­ter in this study. The aqueous extract was obtained by pouring boiling water over the plant material (1:20 m/v) and letting it stay for 90 minutes at room temperature. The identification of bioactive compounds in the extract was performed using the UHPLC-DAD-ESI-MS analysis. The content of total phenols and total flavonoids was determined spectrophotometrically by Folin-Ciocalteu and AlCl3 methods, respectively. The antioxidant activity of the extract was also investigated spectropho­tometrically by DPPH and ABTS assays. A discdiffusion method was used in the antimicrobial activity investigation on the following pathogenic microorganisms: Candida albicans, Proteus vulgaris, Pseudomonas aeruginosa, Bacillus subtilis, Staphy­lococcus aureus, Escherichia coli and Klebsiella pneumoniae. Seven components were detected in the obtained extract, while caffeic and rosmarinic acid were identified. The main component in the extract was rosmarinic acid (16.7 g/100 g of dry extract). The content of total phenols was 77.67 mg GAE/g of the dry extract while the content of total flavonoids was 21.21 mg RE/g of the dry extract. The extract concentrations required to neutralize 50% of the initial DPPH radical concentration were 7.38 and 8.18 μg/cm3 after 30 and 20 min of incubation, respectively, as well as 48.6 μg/cm3 with no incubation. The extract concentration required to neutralize 50% of the initial ABTS radical concentration was 96.0 μg/cm3. The obtained extract has shown the highest antimicrobial activity against Candida albicans fungus. The presented results indicate that the aqueous earth smoke extract should be rightly considered as a potential source of natural antioxidants and antimicrobial agents.