In Vitro Determination of Free Radical Scavenging and Antimicrobial Effects of Mistletoe (Viscum album L.) Extracts

Abstract

Aim: Viscum album L. is a widespread evergreen hemiparasitic shrub native to Europe and Asia. Its leaves and young twigs are traditionally utilized in the treatment of circulatory and respiratory disorders. This study aimed to evaluate the total phenolic content (TPC), antimicrobial efficacy, and antioxidant capacities of extracts obtained from the aerial parts of V. album subsp. album and V. album subsp. austriacum.
Material and Methods: The TPC of the aerial part extracts was determined using the Folin-Ciocalteu assay, while antioxidant activity was assessed via the DPPH scavenging method. The antimicrobial potential was evaluated by determining the Minimum Inhibitory Concentration (MIC) using a modified broth microdilution method. The extracts were tested against Escherichia coli ATCC 8739, Staphylococcus aureus ATCC 6538, Candida tropicalis ATCC 750, C. albicans ATCC 90028, and C. krusei ATCC 14243, with ciprofloxacin and fluconazole serving as reference standards. 
Results: Total phenolic content ranged from 31.4 to 90.9 mg GAE/g extract (p<0.05). Methanol and ethanol extracts exhibited potent antioxidant activity; the lowest IC50 value was recorded as 0.221±0.052 mg/mL for the V. album subsp. austriacum methanol extract. A selective antimicrobial profile was observed: ethyl acetate extracts demonstrated anticandidal effects (MIC: 78.125–156.25 μg/mL), whereas antibacterial activity against E. coli and S. aureus was limited (MIC: 625 to 2500 μg/mL). Polar extracts generally showed weak inhibition, indicating a targeted rather than broad-spectrum antimicrobial potential.
Conclusion: This study provides a scientific rationale for the traditional use of V. album by correlating its phenolic-driven antioxidant capacity with circulatory health and its selective antifungal properties with infection management.

Keywords

• Viscum album
• antimicrobial activity
• antioxidant effect

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