The inherent anti-Candida properties of cinnamon leaf essential oil and the combination effects between cinnamon leaf and clove essential oils on Candida species
學生姓名:
杜庭妤
指導教授:
黃崇雄
學期:
112下
摘 要:
Plant-based essential oils (EO) are promising anti-virulence agents against the multidrug resistant opportunistic pathogen Candida spp. Cinnamon leaf (CNL) and clove (CLV) EOs identified eugenol as the predominant component, with proven fungicidal activity. Among all Candida species, C. albicans is the most frequent etiological agent in fungal infections. This report aims to investigate the efficacy of CNLEO against 3 types of Candida spp. (including C. albicans, C. tropicalis and C. dubliniensis), and elaborate on whether the combination effect of CNLEO and CLVEO enhances the anti-Candida ability. The major component of both EOs was determined as eugenol with gas chromatography-mass spectrometry (GC-MS). The minimum inhibitory concentration (MIC) was determined using broth microdilution, showing that CNLEO has the same MIC against 3 types of Candida spp., and the MIC values of both oils would be used to estimate the combination effect, showing that they are additive and synergistic against C. albicans. The effect of CNLEO on initial adhesion of Candida spp. was quantified using XTT assay, showing the attenuation of adhesion after treatment; the germ tube formation would be observed by Neubauer improved counting chamber, as for the anti-biofilm activity, XTT viability assay, scanning electron microscope (SEM) and Time lapses microscope would be used to perceive the variation, result shows a decreased development of biofilm and germ tube formation after treatment, and it also shows no lethal effect with Galleria mellonella larvae model. Through membrane leakage assay, yeast-to-hyphal transition assay and mycelial growth assay, CNLEO and CLVEO were both found to be effective on reducing growth and dimorphism transition at MICs and half of the lowest combined lethal concentration. Mutant strains 𝑎𝑙𝑠1∆ /∆, 𝑎𝑙𝑠3 ∆/∆, ℎ𝑤𝑝1∆/𝐻𝑊𝑃1 +, and 𝑒𝑓𝑔1∆/∆ were sensitive to either or both oils. In conclusion, CNLEO can reduce the virulence factor of Candida, and the ability would be enhanced when combined with CLVEO.
杜庭妤.pdf