White Mulberry (Morus alba L.) Extracts Modulate Candida albicans Biofilm Formation: A Biological and Genetics-Relevant Perspective

Morus alba L., or white mulberry, is a small deciduous shrub from the Moraceae family, with well-known medicinal properties and beneficial effects on human health. Recent studies have confirmed the bioactive potential of this plant, including its antimicrobial effects, primarily against bacteria and viruses. In contrast, data regarding its antifungal activity are scarce. The main goal of this study was to evaluate the antifungal and antibiofilm capacity of white mulberry ethanolic and methanolic extracts derived from leaves and fruits against Candida albicans, through the measuring of fungal growth inhibition in the agar diffusion method; determining the minimum inhibitory concentration (MIC) by the broth microdilution method; defining the minimum fungicidal concentration (MFC); evaluation of the antibiofilm capacity of the extracts through the tissue culture plate method; and calculation of the biofilm-inhibition percentage. The fruit methanolic extract achieved the largest inhibition zones (31.00±1.00 mm), followed by the fruit ethanolic extract (30.00±1.00 mm). MIC values for all tested samples were defined at 125 µg/ml, while MFC values were determined at 250 µg/ml. In this study, C. albicans was evaluated as a strong biofilm former, and white mulberry extracts showed the potential to change the biofilm-forming capacity in subinhibitory concentrations. Fruit methanolic extract decreased this capacity in a wide range of concentrations, with biofilm inhibition up to 92.61%. Results indicate that white mulberry represents a strong candidate for further investigation in phytotherapy.