Screening of antimicrobial and antioxidant activity of commercial Melaleuca alternifolia (tea tree) essential oils

Abstract

The paper deals with the investigation of the chemical composition, antimicrobial and antioxidant activity of four commercial products of Melaleuca alternifolia essential (TTO). The chemical composition was determined using gas chromatography mass spectrometry (GC/MS) analysis. The broth-microdilution method was used to test antimicrobial activity. The antioxidant activity was tested by stable free radical of the 2,2-diphenyl-1-picrylhydrazyl (DPPH). Results of the chemical analysis identified over 30 components. The composition of the four samples varied and the major components included the following: terpinen-4-ol, γ γ γ γ-terpinene and α α α α-terpinene, respectively. The samples were compliant to the ISO Standard 4730. All TTOs presented similar degrees of antimicrobial activity. A slightly higher activity was shown by TTO 4 , having a balanced level of the three main components: terpinen-4-ol (34.58%) γ γ γ γ-terpinene (9.89%) and α α α α-terpinene (12.59%). Fungi were more sensitive than bacteria and yeast. All TTOs tested possessed the concentration-dependent antioxidant activity. Antioxidant activity was based on a balanced chemical composition between terpinen-4-ol and terpenic compounds. Biological testing confirmed the TTO antimicrobial activity against a wide range of the Gram-positive and Gram-negative bacteria, and fungi and yeasts. The correlation between the chemical composition and biological activity was quite evident. In conclusion, this study's results reveal not only the biological activity of TTO, but also its potential as an antioxidative agent.

Antimicrobial synergism and cytotoxic properties of Citrus limon L., Piper nigrum L. and Melaleuca alternifolia (Maiden and Betche) Cheel essential oils

“…Thirteen compounds constitute 100% of our C. limon EO sample; the major ones were limonene (37.5%), followed by β‐pinene (17.9%), p‐cymene (6.9%) and β‐bisabolene (6.4%). In our previous studies, analysis of P. nigrum EO revealed 12 compounds covering 98.44% of the total EO content, with β‐pinene (34.4%), δ‐3‐carene (19.7%), limonene (18.7%) α‐pinene (10.4%) and caryophyllene oxide (9.2%) being the most abundant ones, while in the EO sample of M. alternifolia oil, 31 constituents covered 99.83% of the oil content, among which terpinen‐4‐ol (38.6%), γ‐terpinene (21.7%) and α‐terpinene (9.1%) were the predominating ones . Similar to our findings, several authors reported limonene as the major lemon oil constituent and, apart from it, citral, neral, geranial and β‐pinene were constituents highlighted as biologically active and also present in few other citrus oils.…”

“…The purpose of this study was to examine chemical composition of the EOs from Citrus limon , Piper nigrum and Melaleuca alternifolia, and their synergistic antimicrobial and cytotoxic properties, as the EOs originating from the same plant species have already confirmed their antimicrobial, anti‐inflammatory and antioxidant properties in available literature . Our wide interest in therapeutic values of medicinal and aromatic plants drove us to conduct study with these three EOs of known chemical composition in order to reveal additional antimicrobial data when the oils are used single or in combinations and to check the EOs cytotoxicity to tumour and non‐tumour human cells, so that the obtained results would contribute to validation of their application against major human oral pathogens.…”

In Vitro Evaluation of Antioxidant and Antimicrobial Activities of Melaleuca alternifolia Essential Oil

“…Several studies conducted on natural plant essential oils have indicated that these oils may be used as antimicrobial agents and have potential use in industrial applications [ 10 – 12 ]. M. alternifolia , also known as tea tree, has been investigated as an alternative antimicrobial agent [ 13 ]; however, there is no information that focuses exclusively on the antioxidant activities of the essential oil from M. alternifolia .…”

Structural behavior, FTIR spectra of five Algerian honeys, and sensory acceptance of margarine enriched with honey

“…The degradation of the DPPH solution was estimated according to the method reported by Noumi et al (2011). The 2,2′-azino-bis 3-ethylbenzothiazoline-6-sulfonic acid (ABTS) test was performed according to the method F I G U R E 1 Photographs of margarines enriched with honey.…”