CONICET | Buscador de Institutos y Recursos Humanos

The resistance to antifungal drugs has become an emerging problem in the treatment of Candida infections worldwide (2). Natural compounds recently appeared in combined alternative therapy to reduce the doses of conventional drugs, providing the additional benefit of decreased toxicity effects on health (3). Fluconazole (FLCZ), an antifungal agent of the azole group, inhibits the biosynthesis of ergosterol disrupting plasma membrane integrity of fungal cells (4). We have previously isolated a sunflower mannose-binding lectin (Helja) with antifungal activity on C. albicans. Helja interacts with yeast cell wall and triggers the production of hydrogen peroxide and the loss of cell integrity and viability (5). The aim of this work was to evaluate the effect of Helja in combination with FLCZ on the growth of C. albicans. Yeast cells were incubated in the presence of Helja (100 µg/ml), FLCZ (1 µg/ml) or combination of Helja-FLCZ to follow optical reading at 630 nm and assess fungal growth. The inhibition of fungal growth in the presence of Helja or FLCZ was 30.91% ± 5.27 and 28.12% ± 11.5 respectively, while the combination Helja-FLCZ exhibited an inhibitory effect of 91% ± 3.5, greater than the sum of both. In addition, cells treated with Helja-FLCZ showed differentials morphological alterations compared to treatment with Helja or FLCZ alone, such as loss of the typical oval form of yeast and the formation of clusters with agglutinated cells. Thus, combination Helja-FLCZ leads to the collapse of cells and their inability to reproduce. The synergistic action of Helja in combination with FLCZ might be helpful in preventing the development of drug resistance and decreasing toxicity, thus it constitutes a promising therapeutic strategy in antifungal treatments.