Anti-Biofilm and Human Nail Permeation Properties of Two Green Propolis Extracts

Onychomycosis is the most common nail infection, it has been attributed to fungal biofilms, and its treatment success is uncertain yet, but some natural products seem promising for topical treatment. The use of natural residues can also contribute to environmental sustainability and serve as valuable sources of bioactive compounds. This study aimed to evaluate the effectiveness of alcoholic propolis extract (PE) and a by-product extract (WPE) on monospecies mature fungal biofilms, and their permeation capacity in the human nail. The extracts were applied on seven-day biofilms produced by Fusarium oxysporum and Trichophyton rubrum, two important and antifungal resistant agents of onychomycosis. Photoacoustic spectroscopy evaluated the permeation of extracts across the nail fungal biofilms. Both extracts were able to significantly reduce the formed biofilms: WPE inhibited biofilms from both fungi at 137.50 μg/mL and PE was effective at 856.26 μg/mL (F. oxysporum) and 428.13 μg/mL (T. rubrum). Furthermore, both extracts showed a nail complete permeation, and WPE was the most efficient. Thus, our results confirm that these extracts would be safe and effective options for topical treatment for onychomycosis.

Keywords:
Trichophyton rubrum; Fusarium oxysporum; biofilms; biological products; dermatomycoses.

Two different propolis extracts significantly reduced the biofilms formed by filamentous fungi.

A by-product extract is as efficient as the original alcoholic propolis extract.

Both extracts completely permeated the nail, with WPE being the most efficient.

Both extracts would be safe and effective for topical treatment of onychomycosis.