TITLE:
Essential oil of Thymus vulgaris L. and Rosmarinus officinalis L.: Gas chromatography-mass spectrometry analysis, cytotoxicity and antioxidant properties and antibacterial activities against foodborne pathogens
AUTHORS:
Hanene Miladi, Rihab Ben Slama, Donia Mili, Sami Zouari, Amina Bakhrouf, Emna Ammar
KEYWORDS:
Thymus vulgaris L.; Rosmarinus officinalis L.; GC–MS; Cytotoxicity; Antioxidant Activity; Antimicrobial Activity
JOURNAL NAME:
Natural Science,
Vol.5 No.6,
June
17,
2013
ABSTRACT:
The
essential oil composition of Thymus vulgaris L. and Rosmarinus officinalis L.
endemic to France were determined by GC and GC-MS. Oils were assessed for their
cytotoxic, antioxidant and antimicrobial activity. 31 and 37 different
compounds were identified representing 99.64% and 99.38% of the thyme and
rosemary oils respectively, where oxygenated monoterpenes constituted the
main chemical class. Thymol (41.33%) and 1.8-cineole (24.10%) were identified
as the main constituents of T. vulgaris L. and R. officinalis L., respectively.
Essential oils (EOs) of selected plant species were evaluated for their in
vitro cytotoxicity against the human lung adenocarcinoma epithelial cell line
(A549). Cytotoxicity was measured using MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphynyltetra-zolium bromide] colorimetric assay. Dose-dependent studies revealed IC50 of
8.50 ± 0.01 μg/mL and 10.50 ± 0.01 μg/mL after 72 h on the A549 cells for R.
officinalis L. and T. vulgaris L., respectively. Antioxidant activity was
determined using a quantitative DPPH (1,1-diphenyl- 2-picryl hydrazyl) assay.
Thymus and rosemary EOs exhibited effective radical scavenging capacity with
50% inhibitory concentration (IC50) of 437 ± 5.46 μg/mL and 189 ± 2.38 μg/mL
respectively and therefore acts as a natural antioxidant agent. The
antimicrobial activity of these species has also been studied against several
foodborne pathogens and food isolated Salmonella spp. including S.
enteritidis of significant importance. According to the results, T. vulgaris
L. showed higher bactericidal effect than those from R. officinalis L. These
results suggest that the essential oil from T. vulgaris L. and R. officinalis
L. have potential to be used as a natural cytotoxic, antioxidant and antimicrobial
agent in food processing.