Helichrysum italicum (Roth) G. Don essential oil: composition and potential anti-tumour, anti-inflammatory, antimicrobial, and antibiofilm effects

Abstract

Essential oils are volatile, aromatic compounds produced in various parts of plants. They are widely used in the pharmaceutical, food and cosmetics industries thanks to their wide range of biological activities. In the current research, the compounds of Helichrysum italicum (Roth) G. Don ssp. italicum essential oil have been identified along with, its anti-tumor, anti-inflammatory, antimicrobial, and anti-biofilm potential. Gas Chromatography-Flame Ionization Detection/Mass Spectrometry (GC/ FID-MS) analysis revealed that monoterpene hydrocarbons (31.45%) were the most abundant components, followed by sesquiterpene hydrocarbons (24.82%): oxygenated monoterpenes (18.00%): beta-diketones (10.06%): esters (8.53%): oxygenated sesquiterpenes (5.22%): and ketones (0.56%). The cytotoxic activity of the essential oil was assessed on G361 human melanoma cells using the WST-1 assay, yielding an IC50 value of 125 mu g mL-1. Cell lysates were obtained by treating G361 cells with different concentrations of the essential oil. The total antioxidant capacity, total oxidant, oxidative stress index of the cell lysates were also explored. Additionally, the levels of anti-inflammatory cytokines (TNF-alpha, IL-1 alpha, and IL-6) were measured. Antimicrobial activity was determined via the disc diffusion method. Gram-positive bacteria (Listeria monocytogenes ATCC 19115, Staphylococcus aureus ATCC 25923, Bacillus subtilis NRS 744): Gram-negative bacteria (Klebsiella pneumoniae NRRLB 4420, Pseudomonas aeruginosa ATCC 27853, Escherichia coli ATCC 25922): and the fungal strain Candida albicans ATCC 10231 were tested. The minimum inhibitory concentration values were determined to range between 250.18 and 510.55 mu g mL-1. The antibiofilm activity, evaluated using the MTT assay, showed the highest inhibition (71.24%) and eradication (73.20%) against S. aureus. These findings suggest that Helichrysum italicum essential oil may have potential as a source of antitumor and antimicrobial compounds