Comparative Evaluation of Antibacterial and Antioxidant Efficacy of Essential Oils of Cymbopogon citratus and Eucalyptus globulus

Humans are constantly exposed to pathogenic vectors such as bacteria, fungi, viruses, mosquitoes, flies, and insects, which are responsible for the transmission of various diseases. While modern healthcare predominantly relies on allopathic medicines, their prolonged use may lead to adverse side effects. In search of a safer alternative, herein, Essential Oils (EOs) were extracted from the dried leaves of Lemongrass (Cymbopogon citratus) and Eucalyptus (Eucalyptus globulus) via hydrodistillation using a Clevenger apparatus. The EOs were characterized using GC-MS (Gas Chromatography Mass Spectroscopy). Further, the antibacterial efficacy was evaluated by the agar well diffusion method against Staphylococcus aureus (Gram-positive) and Escherichia coli (Gram-negative) bacteria. The results of the study have revealed that EO of Eucalyptus (E. globulus) exhibited higher efficacy against E. coli, while Lemongrass (C. citratus) EO was more effective against S. aureus. Furthermore, the antioxidant activity was assessed by 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay, with ascorbic acid as a standard, indicating that Lemongrass (C. citratus) EO possessed higher antioxidant activity than Eucalyptus (E. globulus) EO. GC-MS analysis identified the major volatile compounds in Lemongrass (C. citratus) EO as E-citral (26.32%), Z-citral (16.35%), Nerol (14.46%), and Geraniol (11.38%). The predominant compounds in Eucalyptus (E. globulus) EO were ϒ-terpinene (45.81%), β-pinene (16.21%), α-pinene (5.60%), Eucalyptol 1.94%, Camphene 1.91% and D-limonene 1.94%. The EOs of Lemongrass (C. citratus) and Eucalyptus (E. globulus) exhibit promising antibacterial and antioxidant properties, supporting their potential applications in food preservation, cosmetics, mosquito repellents, and pharmaceutical formulations.