Antifungal activity against Candida albicans biofilm of Coffea robusta monofloral honey from Vietnam

Abstract

Coffee (Coffea robusta) flower honey is one of the highest-yielding kinds of honey in Vietnam. Nevertheless, there is little research on the antifungal activity associated with this type of honey. Therefore, this study was conducted to investigate the antifungal activity against C. albicans of Vietnamese coffee monofloral honey and its potential effects on biofilm formation. This study was conducted using the broth microdilution method. The results showed that coffee flower honey was resistant to Candida albicans strain with minimum inhibitory concentration (MIC) and with minimum fungicidal concentration (MFC) values of 50% and 70% (w/v), respectively. No change in the antifungal activity of honey and the antifungal agent (Amphotericin B) against the C. albicans strain occurred after five consecutive exposures. When using SEM, honey at MIC (w/v) strongly affected the two stages of C. albicans biofilm formation. The surface structure of the biofilm, deformed, distorted, and atrophied phenotypes impacted by honey were also observed. Expression of transcriptional-level genes involved in biofilm formation, quorum-sensing, and stress survival was analyzed by RT-qPCR in honey-treated and untreated biofilms. The present study showed the antifungal activity of Vietnamese coffee flower honey against C. albicans.

Keywords

• antifungal activity
• biofilm
• Candida albicans
• honey
• minimum inhibitory concentration (MIC)
• transcription level