Evaluation of the Antioxidant and Antibiofilm Activities of Rosmarinus Officinalis Essential Oil Extract

Abstract

Biological activities of essential oils from various plants, including Rosemary, have been attributed to the
presence of specific chemical compounds with antimicrobial, anti-inflammatory and antioxidant activities.
The aim of this study is to estimate the antioxidant and antifungal activity of Rosmarinus officinalis essential
oil extract. The study included the extraction of essential oil using a Clevenger apparatus. The chemical
compositions were evaluated by GC-MS and High Performance Liquid Chromatography (HPLC).The
rosemary essential oil extract was tested with regard to antioxidant utilizing 2, 2- diphenyl-1-picrylhydrazyl
(DPPH) assay. Microtiter plate Assay used to determine the antifungal and antibiofilm activity. The result
showed that the GC-MS analysis revealed that the major components determined in R. officinalis essential
oil were linalool (17.09 %), L- Borneol (11.92 %), Verbenone (8.52 %), camphor (5.30 %), Eucalyptol
(4.79 %), while the chemical compositions identified by HPLC shows four phenolic acids were identified
in the essential oil, Rosmarinic acid, Caffeic acid, p-Coumaric acid, 4-hydroxybenzoic acid, and lignans
(medioresinol), while Isorhamnetin was the only flavonol detected. The free radicals scavenging activity
increased gradually with the increase in the concentration of essential oil which was 81.59 % when
compared with BHT and V.C (92.34 and 97.42) respectively. The results of the antifungal activity revealed
that Minimum Inhibitory Concentration of C. albicans and C. krusei was 3.125%, while the MIC of C.
glabrata was 12.5% in contrast with the highest MIC which recorded for C. tropicalis at 25% of rosemary
essential oil. The current results revealed that the reduction of bofilm formation among C. albicans and
C. krusei was obvious at the lower concentration (1.56%), where the percentage of biofilm formation in
C. albicans was (91.25%) and C. krusei was (84.25%), while C. tropicalis exhibit (86.32%) for biofilm
reduction at the concentration (12.5%) of rosemary essential oil, also it was found that the effect of essential
oil on C. glabrata biofilm formation was at the concentrations 3.125% and 6.25%. The findings of this study
indicated to the significant effect of rosemary essential oil against the growth and biofilm formation of the
important pathogenic yeast C. albicans at low concentrations.