Promising effect of propolis and a by-product on planktonic cells and biofilm formation by the main agents of human fungal infections

Abstract

Few antifungals available today are effective in treating biofi lms. Thus, it is urgent to discover new compounds, such as natural products, that provide improvements to existing treatments or the development of new antifungal therapies. This study aimed to perform a comparative analysis between the green propolis extract (PE) and its by-product, a waste of propolis extract (WPE) through a screening with Candida sp., Fusarium sp. and Trichophyton sp. The antifungal property of PE and WPE was assessed by the minimum inhibitory concentration (MIC) and minimum fungicidal concentration (MFC) determination in planktonic cells. The infl uence of both extracts on the inhibition of biofi lm formation in these fungi was also tested. The WPE MIC and MFC values (68.75 to 275.0 µg/mL) were three to twelve times lower than the values obtained for PE (214.06 to 1712.5 µg/mL). PE was more effi cient than WPE in inhibiting the biofi lm initial phase, especially in C. albicans. Meanwhile, WPE had dose-dependent behavior for the three fungi, being more effective on fi lamentous ones. Both PE and WPE showed excellent antifungal activity on planktonic cells and demonstrated great effi cacy for inhibiting biofi lm formation in the three fungi evaluated.