Bioprospecção de extratos de Schinus sp. com atividade antifúngica frente Candida spp. e sua interação com droga antifúngica

Abstract

The increasing incidence of fungal infections, combined with the emerging resistance of species such as Candida albicansand Candida glabrata to conventional antifungals like fluconazole, highlights the urgent need for new therapeutic approaches. Fungal infections are becoming increasingly prevalent in both hospital and community settings, with C. albicans accounting for a significant proportion of cases. Meanwhile, C. glabrata has drawn attention due to its intrinsic and acquired resistance to several antifungal agents. In this context, medicinal plants—particularly Schinus weinmanniifolia—have emerged as potential alternatives for the development of effective antifungal agents. Exploring natural compounds is a promising strategy, as many plants possess bioactive properties that may be useful for both the prevention and treatment of infections. This study aimed to determine the Minimum Inhibitory Concentration (MIC) of the aqueous leaf extract of S. weinmanniifolia and to evaluate its synergy with fluconazole against C. albicans and C. glabrata strains. Leaves were collected in regions of Mato Grosso do Sul, Brazil, and the aqueous extract was prepared by infusion in boiling water. After filtration and lyophilization, the extract was tested by broth microdilution to determine the individual MICs of the extract and fluconazole. The synergistic interaction was then evaluated using the checkerboard method, with calculation of the Fractional Inhibitory Concentration Index (FICI). The results showed that the aqueous extract presented MICs of 1.95 µg/mL for C. albicans and 0.48 µg/mL for C. glabrata, indicating strong antifungal activity. The combination of the extract with fluconazole revealed a significant synergistic effect, with FICI values of 0.48 for C. albicans and 0.75 for C. glabrata, demonstrating that the association enhances antifungal efficacy, even against clinically resistant strains. It is concluded that the aqueous extract of S. weinmanniifolia presents significant therapeutic potential, both alone and in combination with conventional antifungals. The observed synergy suggests a promising alternative for overcoming fungal resistance, reinforcing the importance of investigating natural compounds for the development of new therapies.