Deciphering the Antioxidant, Hemocompatibility, and Antimicrobial Properties of Artemisia arborescens Essential Oil

Introduction: Artemisia arborescens L. is an aromatic Mediterranean plant used in traditional folk medicine and valued as a source of biologically active volatile constituents (1,2). This study evaluated the antioxidant, hemocompatibility, and antimicrobial properties of its essential oil (AAEO).

Materials and Methods: DPPH•  and ABTS•+  assays were used to quantify the antioxidant capacity. Hemocompatibility was assessed by incubating human erythrocytes with AAEO (25-400 µg/mL) for 30 minutes at 37°C, then measuring the percentage of hemoglobin release spectrophotometrically. Antibacterial and antifungal activity were evaluated via broth microdilution and resazurin viability assays, and the minimum bactericidal and fungicidal concentrations were determined by subculturing aliquots from wells displaying no microbial growth. 

Results and Discussion:  AAEO exhibited antioxidant activity, with IC₅₀ values of 164.44 ± 7.10 µg/mL and 116.40 ± 2.78 µg/mL in the DPPH• and ABTS•+ assays, respectively.  At 25, 50, and 100 µg/mL, hemolysis did not reach 5%, which is the standard mean hemolytic threshold above which a substance is considered hemolytic. At 200 and 400 µg/mL, hemolysis increased to 9.8% and 13.0%, suggesting a concentration-dependent hemolytic effect at higher concentrations. Hemolysis at all tested concentrations remained significantly lower than that of the positive control (p < 0.0001). AAEO inhibited Staphylococcus aureus with an MIC and MBC of 2% (v/v), whereas those values for Enterococcus faecalis, Escherichia coli, and Klebsiella pneumoniae were >2% (v/v). Antifungal activity was observed against Penicillium cyclopium and Candida albicans, with MIC values of 1% and 2% (v/v), respectively. MFC values were >2% (v/v) for both fungi, indicating no fungicidal activity within the tested concentration range. Overall, AAEO demonstrated antioxidant activity, favorable erythrocyte compatibility at concentrations up to 100 µg/mL, while higher concentrations produced a measurable hemolytic response and selective antimicrobial effects.

References

1. Plescia F, Venturella F, Lauricella M, et al. Chemical composition, cytotoxic effects, antimicrobial and antibiofilm activity of Artemisia arborescens (Vaill.) L. growing wild in the province of Agrigento, Sicily, Italy. Plant Biosystems. 2022;156(6):1336–1345. 

2. Lantzouraki DZ, et al. Artemisia arborescens and Artemisia inculta from Crete: Secondary metabolites, trace metals and in vitro antioxidant activities. Life. 2023;13(6):1416.