Essential oil compositions and antioxidant properties of Cycas revoluta (Thunb.)

Cycas revoluta is an ornamental plant which has had some of its parts used in treating some forms of cancers, relieving headaches, giddiness and sore throat. Essential oils from both fresh and air-dried C. revoluta leaf and stalk samples were obtained by hydro-distillation using a Clevenger apparatus with the constituents identified and quantified by Gas Chromatography – Mass Spectrometry (GC-MS) analysis. The fresh leaf and stalk essential oils had 22 and 45 identified essential oil components respectively while the air-dried parts had 25 leaf essential oil and 18 stalk essential oil components. γ-ketovaleric acid (29.36 %), 2,4,4-Trimethyl-2-pentene (13.27 %), lauric acid (9.84 %) and 7-Nonenamide (58.71 %) constituted the major components of the fresh leaf, fresh stalk, dry leaf and dry stalk essential oils respectively. Free radical scavenging ability of the essential oils was assayed with 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging method and the four essential oil samples recorded anti-oxidant activities which were concentration dependent with the dry leaf essential oil exhibiting the highest activity at 1 mg/mL with a 72 % inhibition. These values were comparable with the currently known antioxidant standards.