Antibacterial and antioxidant activities of bilberry (Vaccinium myrtillus L.) in vitro

Abstract

Antibacterial and antioxidant activity, total phenolic and flavonoid concentrations of water, ethanol and ethyl acetate extract of fruits and leaves of Vaccinium myrtillus L. were studied. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) have been determined. Testing was performed on 30 clinical isolates, including strains of Escherichia coli, Enterococcus faecalis and Proteus vulgaris. The values for MIC were in the range from 5 to 40 mg/ml. The most sensitive bacterial strain was Enterococcus faecalis MF-Ef8 strain. The ethanol extract of fruits of V. myrtillus was found the most active. The total phenolic content was determined using Folin-Ciocalteu reagent and ranged between 31.44 to 119.17 mg GAE/g. The concentration of flavonoids in extracts was determined and the highest amount was in ethyl acetate extract of leaves of V. myrtillus. Antioxidant activity was monitored spectrophotometrically using 2,2-diphenyl-1-picrylhydrazyl (DPPH) reagent. The highest capacity to neutralize DPPH radicals (94%RSA) was found in the ethanol extract from fruits and in the water extract from leaves of V. myrtillus. The results of the total phenolic content determination of the examined extracts indicate that bilberry extracts are a rich source of phenolic compounds and also possess a significant antioxidant activity and moderate antibacterial activity.

Establishment of a Sonotrode Extraction Method and Evaluation of the Antioxidant, Antimicrobial and Anticancer Potential of an Optimized Vaccinium myrtillus L. Leaves Extract as Functional Ingredient

“…On the contrary, sorbic acid is more efficient against Gram-negative bacteria and fungi. In general, and according to the results obtained in this paper and in the literature, Gram-positive bacteria are more sensitive to plant extracts than Gram-negatives and fungi [ 2 , 46 , 47 ]. The higher sensitiveness of Gram-positive bacteria to phenolic compounds may be associated with the hydrophilic protection that outer membrane of Gram-negative bacteria and the cell wall of fungi provides by blocking the interaction of external hydrophobic molecules with the microbial cell surface avoiding its destruction [ 46 ].…”

“…Moreover, Dragana et al studied the antimicrobial activity of V. myrtillus leaves extract against human pathogens related to urinary tract infections. They found that E. coli , E. faecalis and P. vulgaris were sensitive to the bioactive compounds in bilberry fruits and leaves [ 47 ]. Thus, bilberry leaves extract can be considered a source of antimicrobial molecules that may be used in the food industry as preservatives or for the development of functional food or nutraceuticals.…”

Yabanmersi̇ni̇ (Vacci̇ni̇um Myrti̇llus L.) Meyve Özü'nün Mi̇de Kanseri̇, Ags Hücre Hatti Üzeri̇nde Anti̇oksi̇dan Akti̇vi̇tesi̇ Ve Anti̇-Kanser Etki̇leri̇

“…In a previous study, the fruit extract was able to inhibit lipid peroxidation (IC50 = 50.28 μg/mL) and to scavenge superoxide anion (IC50 < 25 μg/mL). [25][26][27][28]. Studies explaining that the high antioxidant capacity of bilberry extracts is related to the phenolic compounds they contain [9,[29][30][31].…”

Comprehensive phytochemical analysis of lingonberry (Vaccinium vitis-idaea L.) from different regions of China and their potential antioxidant and antiproliferative activities

“…12 Lingonberry leaves are used as an important raw material for making tea, as they contain high levels of polyphenols and possess strong antimicrobial and antioxidant properties. 13 Compared to other parts of the plant, the fruit of the lingonberry has a higher accumulation of triterpenoid constituents. Plants triterpenoids exist in free and bound forms with different polarities and solubilities.…”