Inhibitory effects of berberine on Fonsecaea monophora in vitro and in vivo.

BACKGROUND: Chromoblastomycosis (CBM) is a chronic and difficult-to-treat infection caused by dematiaceous fungi, primarily affecting the skin and subcutaneous tissues. In Southern China, Fonsecaea monophora is recognized as a predominant pathogen agent of CBM cases. Effective therapeutic strategies remain limited for this mycosis. However, berberine, a bioactive compound extracted from various traditional medicinal herbs, has attracted considerable attention due to its potent antimicrobial properties. METHODS: The study evaluated the antifungal efficacy of berberine against F. monophora through a series of in vitro studies, including antifungal susceptibility testing and time-kill curve analysis. Moreover, a Galleria mellonella infection model of F. monophora was also established for the comparative analysis of berberine’s efficacy. RESULTS: Berberine exhibited inhibitory activity against all tested strains. The minimum inhibitory concentrations (MICs) of berberine against F. monophora strains ranged from 16 to 64 µg/mL, with a geometric mean of 49.74 µg/mL. In the Galleria mellonella model, berberine treatment significantly prolonged the survival time of infected larvae. CONCLUSION: These findings suggest that berberine has the potential, as a complementary treatment, for CBM. However, the current research is limited to in-vivo and preliminary in-vitro model involving a small number of fungal strains. Therefore, further validations through additional studies, such as involving murine model and other advanced experimental systems, will be necessary.