Chemical analysis, antioxidant, antiinflammatory and anticholinesterase activities of Origanum ehrenbergii Boiss and Origanum syriacum L. essential oils

The essential oils of Origanum ehrenbergii and O. syriacum collected in Lebanon were analysed by GC andGC–MS and evaluated for their anticholinesterase, NO production inhibitory activities, and antioxidantproperties. O. ehrenbergi essential oil was characterised by the presence of 37 components, representing94.9% of the total oil of which thymol (19%) and p-cymene (16.1%) were the main abundant compounds.Thirty-six compounds characterised the O. syriacum essential oil, representing 90.6% of the total oil. Themost abundant components were thymol (24.7%) and carvacrol (17.6%). O. ehrenbergii demonstratedinteresting scavenging effects on DPPH with an IC50 value of 0.99 microg/ml. In addition, both O. ehrenbergiiand O. syriacum oils inhibited oxidation of linoleic acid after 30 min of incubation, as well as after 60 minof incubation with IC50 values of 42.1 and 33.6 microg/ml, and 46.9 and 58.9 microg/ml, respectively. Interestingly,O. ehrenbergii oil inhibited NO production in the murine monocytic macrophage cell line RAW264.7 with an IC50 value of 66.4 microg/ml. Acetylcholinesterase (AChE) and butyrylcholinesterase (BChE)inhibition was assessed by modifications of the Ellman’s method. O. ehrenbergii exhibited a strong activityagainst both cholinesterases with IC50 values of 0.3 microg/ml. The data suggest that O. ehrenbergii and O. syriacumoils could be used as a valuable new flavour with functional properties for food or nutriceuticalproducts with particular relevance to supplements for the elderly.