Resumo

Introduction: Cryptococcosis is a systemic infection and oportinista caused by yeast Cryptococcus neoformans and C. gattii which can affect immunocompetent and immunocompromised hosts. It is estimated that more than one million cases of cryptococcosis occur per year in HIV positive individuals, which classifies the disease as the third among the most important systemic fungal infections. Treatment is by administration of amphotericin B followed by fluconazole for the long term. The problem of the established antifungal therapy consists in the development of fungal resistance and high toxicity. The study of plants as alternative to the search for new antifungal agents has been a promising alternative. Objective: This study aims to evaluate the antifungal activity of the protocatechuic acid (fraction hexyl), isolated from the plant Cupania oblongifolia, against C. neoformans and C. gattii as well as the assessment of cytotoxicity even in the oral mucosa keratinocytes (NOK). Methods: The antifungal activity of protocatechuic acid (fraction hexyl) was evaluated by determining the minimal inhibitory concentration (MIC) and minimal fungicide concentration (MFC), according to the EUCAST document EDef7,2 (2008) with modifications against isolates enviromental, resistant and sensitive clinical isolates of C. neoformans, an isolated animal C. gattii fluconazole resistant and strain C. neoformans ATCC 90012. Was used as control anfotercina B. Cytotoxicity was assessed by the MTT reaction at NOK cells. Results and Discussion: The protocatechuic acid (fraction hexyl) showed strong activity against isolates of C. neoformans and C. gattii with a MIC and MFC ranged from 3.91 to 15.62 mg/L, indicating a fungicidal activity. The IC50 of the protocatechuic acid (fraction hexyl) in cells NOK presented concentration of 25.20 mg/L and a selectivity index (SI) of 6.44 for yeast which shows the use of security the protocatechuic acid (fraction hexyl) for the treatment of cryptococcosis. Conclusion: Our results showed that the compound of protocatechuic acid (fraction hexyl) has a strong activity anti-Cryptococcus and low cytotoxicity for keratinocytes as well as a high selectivity of the antifungal compound to the yeast and may be a promising prototype for the development of a new antifungal therapy.