Chemical composition and in vitro evaluation of antioxidant, antimicrobial, cytotoxicity and anti-acetylcholinesterase properties of Tunisian Origanum majorana L. essential oil

This study investigated the chemical composition and evaluated the antioxidant, antimicrobial, cytotoxic and anti-acetylcholinesterase properties of Tunisian Origanum majorana essential oil. The findings showed that the oil exhibited high activity, particularly in terms of reducing power and β-Carotene bleaching, inducing higher IC50 values than BHT. The oil showed an important antimicrobial activity against 25 bacterial and fungal strains. In fact, the IZ, MIC and MBC values recorded for the bacterial strains were in the range of 8 ± 0–18.33 ± 0.57 mm, 0.097–3.125 and 0.39–6.25 mg/mL, respectively. The IZ, MIC and MFC values of the fungal strains varied between 11±0–28 ± 0 mm, 0.058–0.468 mg/mL and 0.234–1.875 mg/mL, respectively. A low cytotoxic effect was observed against cancer (Hep-2 and HT29) and continuous cell lineage (Vero), with CC50 values ranging from 13.73 to 85.63 mg/mL. The oil was also evaluated for anti-acetylcholinesterase effects, which showed that it exhibited significant activity with IC50 values reaching 150.33 ± 2.02 μg/mL. •This study represents the first attempt to identify the chemical composition of Tunisian Origanum majorana L. essential oil and to evaluate their biological activities especially their potency against several human pathogenic species of bacteria and fungus, their antioxidant activities through four tests, cytotoxicity and anti-acetylcholinesterase properties.•Our results suggest that this essential oil may be considered as an interesting source of bioactive components.•Hence, paving the way for solid support for their pioneering candidacy for future use as natural agents in different applications, including food preservation, cosmetic preparations, dermatological and pharmaceutical compositions, and medical or healing products.