Bioactive, antioxidant and antimicrobial properties of chemically fingerprinted essential oil s extracted from Eucalyptus globulus: in-vitro and in-silico investigations

Said Nasir Shah; Ibrar Khan; Sidra Tul Muntaha; Azam Hayat; Mujaddad Ur Rehman; Tawaf Ali Shah; Farhan Siddique; Ahmad Mohammad Salamatullah; Amare Bitew Mekonnen; Mohammed Bourhia

doi:10.3389/fchem.2023.1287317

Bioactive, antioxidant and antimicrobial properties of chemically fingerprinted essential oil s extracted from Eucalyptus globulus: in-vitro and in-silico investigations

Front Chem. 2023 Dec 8:11:1287317. doi: 10.3389/fchem.2023.1287317. eCollection 2023.

Affiliations

¹ Department of Microbiology, Abbottabad University of Science & Technology, Abbottabad, Pakistan.
² Department of Zoology, Abbottabad University of Science & Technology, Abbottabad, Pakistan.
³ Department of Biotechnology, University of Okara, Okara, Pakistan.
⁴ Laboratory of Organic Electronics, Department of Science and Technology, Linköping University, Linköping, Sweden.
⁵ Department of Food Science and Nutrition, College of Food and Agricultural Sciences, King Saud University, Riyadh, Saudi Arabia.
⁶ Department of Biology, Bahir Dar University, Bahir Dar, Ethiopia.
⁷ Laboratory of Chemistry and Biochemistry, Faculty of Medicine and Pharmacy, Ibn Zohr University, Agadir, Morocco.

Abstract

Innovative approaches are urgently required to treat divestating bacterial diseases in the face of rising bacterial resistance rates. The current investigative work focused on hydro-distilling Tasmanian blue gum (Eucalyptus globulus) to isolate the essential oil, which was then tested for bioactivity, antioxidant capacity, and antibacterial activity using in-vitro and in silico assays. The antioxidant activity was avualated against DPPH and FRAP. With results of 69.63 RSA (%) (µL/L AAE) at a concentration of 5 mL/L and 51.56 (µL/L AAE) at concentration of 90 ppm in the 2,20-diphenyl-1-picryl hydrazyl (DPPH) and ferric reducing antioxidant power (FRAP) assays, respectively, the extracted oil indicated considerable antioxidant activity. The extracted oil demonstrated powerful antibacterial activity in in-vitro tests against both Gram-positive and Gram-negative bacterial strains, including Bordetella bronchiseptica (21 mm), Staphylococcus epidermidis (19 mm), and Staphylococcus aureus (19 mm), with significant minimal inhibitory (MIC) and minimum bactericidal (MIB) concentrations. Additionally, GC-MS analysis of the oil from E. globulus identified several low-molecular-weight compounds, including Eucalyptol, γ-Terpinene, Shisool acetate, 1,3-trans,5-cis-Octatriene, 2,6-Dimethyl-1,3,5,7-octatetraene, E,E, Cyclohexene, 1-methyl-4-(1-methylethylidene), Benzene, 1-methyl-4-(1-methylethenyl), Butanoic acid, 3-methyl-, 3-methylbutyl ester, and 1,3,8-p-Menthatriene. Several other compounds were also identified, including Fenchol, 2-Methyl-trans-3a,4,7,7a-tetrahydroindane, (E,E,E)-2,4,6-Octatriene, 1,2,3,6-Tetrahydrobenzylalcohol, acetate, Alloaromadendrene, Phenol, 2-ethyl-4,5-dimethyl, Phenol, 2-methyl-5-(1-methylethyl)-, p-Cymen-7-ol, 1,5,5-Trimethyl-6-methylene-cyclohexene, 1,3-Cyclohexadiene, 1-methyl-4-(1-methylethyl)-, 2,6-Octadien-1-ol, 3,7-dimethyl-, acetate, (Z), and more. The bioactive potential of Eucalyptus globulus essential oil against 1AJ6 and 1R4U was highlighted by molecular docking analyses, suggesting its utility as a natural source of antioxidant and antibacterial compounds with the potential to replace chemical disinfectants in a variety of applications.

Keywords: Eucalyptus; GC-MS; disinfectants; essential oils; molecular docking.

Grants and funding

The author(s) declare financial support was received for the research, authorship, and/or publication of this article. This work is financially supported by the Researchers Supporting Project number (RSP-2023R437), King Saud University, Riyadh, Saudi Arabia, IUCN Policy statement. The collection of plant material complies with relevant institutional, national, and international guidelines and legislation.