Investigating the anti-fungal effects of fennel oil

In this study, researchers from Fayoum University and Cairo University in Egypt screened the anti-microbial activities of some plant essential oils against isolates of Candida albicans, which causes vulvovaginal candidiasis (VVC), and investigated the anti-fungal effect of the most active essential oil against planktonic and sessile cells. Their findings were published in the Journal of Herbal Medicine.

• To screen the biofilm production of C. albicans, the researchers used tissue culture plate method.
• They tested the fungus’ susceptibility to the anti-fungal fluconazole using disk diffusion method.
• To screen the anti-fungal activities of nine essential oils, the researchers used strong biofilm-producer, fluconazole-resistant or dose-dependently susceptible clinical isolates of C. albicans ATCC 10231.
• They then performed microdilution assay to determine the minimum inhibitory concentration (MIC) of fennel essential oil, fluconazole and their combination against planktonic and sessile cells.
• The researchers reported that 10 out of 19 C. albicans strains showed strong ability to form biofilms.
• None of the tested clinical isolates was sensitive to fluconazole.
• Fennel oil showed much higher anti-fungal activities against the tested C. albicans than any of the other oils.
• The MICs of fennel oil for planktonic cells ranges from 0.78 to 6.25 percent with an MIC50 of 3.12 percent and an MIC90 of 6.25 percent.
• Meanwhile, concentrations of fennel oil ranging between 6.25 to 25 percent resulted in 50 percent biofilm reduction.
• Fennel oil and fluconazole also exerted synergistic effects in seven out of 11 strains. No antagonism was detected between the two anti-fungal agents.

Based on these results, the researchers concluded that fennel oil alone or in combination with fluconazole is a promising treatment for VVC caused by drug-resistant strains of C. albicans.

Read the full study at this link.

Journal Reference:

Bassyouni RH, Wali IE, Kamel Z, Kassim MF. FENNEL OIL: A PROMISING ANTIFUNGAL AGENT AGAINST BIOFILM FORMING FLUCONAZOLE RESISTANT CANDIDA ALBICANS CAUSING VULVOVAGINAL CANDIDIASIS. Journal of Herbal Medicine. 2019;15:100227. DOI: 10.1016/j.hermed.2018.08.002