Chemical profile, enzyme inhibitory and antioxidant activities of essential oils of an endemic Algerian species: Abies numidica. De Lannoy ex Carrière.

The essential oils (EOs) from needles, twigs and cones of Abies numidica, an endemic tree from Algeria, were analysed by gas chromatography (GC), gas chromatography-mass spectrometry (GC-MS) and 13C nuclear magnetic resonance (13C NMR). Fifty, forty-nine, and thirty-eight components from needles, twigs and cones were identified accounting for 86.0%, 93.5% and 93.8% of the total EO, respectively. EOs were mainly composed of monoterpene hydrocarbons (46.3%-86.0%), followed by sesquiterpene hydrocarbons (2.6%-33.6-%). The antioxidant activity was determined using five tests: ABTS, β-Carotene bleaching, DPPH, FRAP and phosphomolybdenum. Cholinesterase inhibition potential of EOs was also evaluated. EO of cones was found to have the highest antioxidant activity for most of the tests performed. All EOs exhibited better antiacetylcholinesterase (AChE) than antibutyrylcholinesterase (BChE) activities at various rates. The most potent AChE inhibition was observed for twigs EO (IC50 = 2.73 g/mL), followed by needles (IC50 = 4.09 µg/mL) while cones' EO showed least potential (IC50 = 13.64 µg/mL). [ABSTRACT FROM AUTHOR]