Essential oils from Anethum graveolens L. and their phytotoxic and antibiofilm potential

Abstract

Essential oils (EOs) from inflorescences (EO-i), stems (EO-s) and leaves (EO-l) of Anethum graveolens are analyzed by GC and GC-MS. The main components are α-phellandrene (51.44%) and p-cymene (22.65%) in the EO-i, p-cymene (50.75%) and α-phellandrene (35.73%) in EO-s and p-cymene (40.01%) and α-phellandrene (36.38%) in EO-l. The phytotoxic activity was tested against germination and growth of aerial parts and roots of dicotyledones (Sinapis arvensis and Trifolium campestre) and monocotyledone (Lolium multiflorum) weeds. The EOs proved to be particularly active against S. arvensis and T. campestre, causing total inhibition of germination and growth at the highest doses (2.0 and 1.5 μL/mL) with IC50 values included between 0.3 and 1.6 mg/mL. The antibacterial and antibiofilm activity was tested against Gram positive (Staphylococcus aureus subsp. aureus and Listeria monocytogenes) and Gram negative (Acinetobacter baumannii, Pseudomonas aeruginosa and Escherichia coli) pathogenic bacterial strains. EOs presented MICs lower than those of Tetracycline (20-24 mg/mL) against most bacterial strains (from 4 to 6 mg/mL). EOs were found to be active in inhibiting bacterial biofilm formation with IC50 values between 1.47 and 3.85 mg/mL. The activity against bacterial metabolism occurred for EO-i and EO-s against A. baumannii and E. coli with IC50 between 0.99 and 5.39 mg/mL. This investigation provides data about the chemical variation among different parts of A. graveolens and encourages the use of its EOs as natural phytotoxic and antibacterial agents in agriculture, food and pharmaceutical sectors.