Chemical characterization, antioxidant and antimicrobial activities of essential oil from Melaleuca quinquenervia leaves

Niaouli oil is an essential oil known for its applications in aromatherapy and pharmaceutical preparations for coughs, colds, rheumatism and neuralgia. It also serves as a sedative, possesses antifungal activity, and used in perfume industry. Melaleuca quinquenervia (Cav.) S.T. Blake, commonly called, paper bark tea tree or punk tree, is a potential source of niaouli oil. Here, we analyzed the chemical composition of essential oil from M. quinquenervia leaves and evaluated its antioxidant and antimicrobial potential. Chemical analysis of the oil by GC-FID and GC-MS revealed 1,8-cineole (31.0%) as a major component followed by p-cymen-8-ol (19.7%), p-cymene (16.5%), α-terpineol (9.9%), limonene (6.8%), α-pinene (4.2%) and terpinolene (4.2%). M. quinquenervia essential oil demonstrated good antioxidant activity by inhibiting 84.3 % of 2,2^׳-diphenyl-1-picrylhydrazyl radical and ferric reducing power (1.94±0.007) at 100 µg/mL. Further, it was highly effective against tested food borne bacterial as well as fungal pathogens inducing 11.0-46.0 mm and 11.8-46.0 mm zones of inhibition, respectively at concentration of 8-250 μg/mL. The high degrees of antibacterial and antifungal activities were further confirmed at 8 μg/mL minimum bactericidal concentrations and minimum fungicidal concentrations, respectively. Time kill assay showed significant bactericidal and fungicidal effects of essential oil for four weeks. The high antimicrobial and antioxidant activities of M.quinquenervia essential oil substantiate its potential use as alternative to chemical preservatives in food industry.

Reference: Siddique, S., S. Mazhar and Z. Parveen (2018). “Chemical characterization, antioxidant and antimicrobial activities of essential oil from Melaleuca quinquenervia leaves.”