Chemical Characterization, Antioxidant and Antibacterial Activity of Essential oil of Cymbopogon winterianus Jowitt (Citronella) from Western Nepal

Essential oils (EOs) are a mixture of volatile compounds of plant origin, which possess substantial biological activities such as antioxidant, antimicrobial, and antifungal activity. This study aimed to determine the chemical composition, antioxidant, and antibacterial activity of essential oil isolated from Cymbopogon winterianusJowitt. The hydro-distillation method was used for the isolation of essential oil. The chemical composition of the isolated essential oil was analyzed using the gas chromatography/mass spectrometry (GC-MS) technique. Antioxidant activity was determined using2,2-Diphenyl-1-picrylhydrazyl(DPPH) free radical scavenging assay, and the IC50 value was calculated. The well-diffusion method was applied for the antibacterial activity, and the zone of inhibition (ZOI) was measured. The essential oil from Cymbopogon winterianusJowitt was isolated with a 0.5% yield. Gas Chromatography-Mass Spectrometry(GC-MS) analysis reported 19 different compounds, out of which, Geraniol (28.87%), Citronellal (11.85%), Citronellol (10.88%), Geranial (9.19%), trans-Geranyl acetate (9.11%), and Neral (8.02%) were found to be the major constituents. The essential oil was a promising antioxidant with an IC50 value of 0.458±0.39µg/mL compared to the standard Quercetin 1.187±0.22µg/mL.In addition, the isolated essential oil revealed antibacterial activity against Staphylococcus aureus (ZOI=13.2mm), Bacillus subtilis (ZOI=9.9mm), and Enterococcus faecalis (ZOI=8.4mm). The essential oil isolated from Cymbopogon winterianusJowittexhibits antioxidant and antibacterial activity, implying that it could find use in modern medicine.