Essential oil of Cymbopogon citratus cultivated in Egypt: seasonal variation in chemical composition and anticholinesterase activity

Abstract

The yield of essential oil obtained by hydrodistillation of Cymbopogon citratus fresh leaves ranged from 0.15% to 0.46% w/w; being the highest in spring and the lowest in winter. The oil sample obtained in winter exhibited a moderate acetylcholinesterase inhibitory activity (IC50 2.86 ± 0.17 mg/mL), compared to physostigmine (IC50 0.012 mg/mL), while other samples were relatively weak (IC50 values of 2.86–5.40 mg/mL). In all samples, oxygenated monoterpenes were predominating (73.22–89.32%). GC-MS identified a total of 61, 25, 50 and 63 components in oil samples obtained in spring, summer, autumn and winter, respectively. Citral content was the highest in autumn and summer samples (82.02% and 80.01% citral; respectively) and the lowest in winter sample (60.01%). Citral, isolated from the oil demonstrated a relatively potent anticholinesterase activity (IC50 0.21 ± 0.01 mg/mL).