Antifungal activity of almond (Prunus amygdalus) hull extracts against clinical isolates of Candida albicans.

Background and purpose: Various attempts have been made to find potent and effective alternatives with natural origin and fewer side effects for the current antifungals. This study aimed to determine the antifungal effects of the Hydroalcoholic Extract (HE) and Lyophilized Extract (LE) of Prunus amygdalus hulls on clinical isolates of Candida albicans. Moreover, their effects were compared with fluconazole.

Materials and methods: Following the preparation of botanical compounds, the toxicity, cell viability, and high-performance liquid chromatography (HPLC) of phenolic compounds analyses were assayed. The broth microdilution method was applied to determine the minimum inhibitory concentration (MIC) values of fluconazole, LEs, and HEs against clinical isolates of C. albicans.

Results: According to the HPLC results, the HEs and LEs comprised the main nine components, of which chlorogenic and tannic acids were the most abundant ones. Results of the toxicity assays revealed that no dilution of the extract was toxic to the cells, and the percentage of cell viability was similar to that of the control and above 90% in all dilutions. All isolates showed susceptibility to fluconazole (MIC range: 0.12-1 μg/mL). The MIC geometric mean values of C. albicans isolates were 0.29, 11.47, and 48.50 μg/mL for fluconazole, LE, and HE, respectively.

Conclusion: Due to their insignificant side effects and cost-effectiveness, these extracts can be introduced as effective antifungals. Further in vivo studies and clinical trials should support the study results.