Atividade antifúngica do extrato hexânico de Psidium guineense (Myrtaceae) contra cepas de Candida glabrata e Candida parapsilosis.

Abstract

Candidiasis is an opportunistic fungal infection caused by microorganisms of the genus Candida, the most common in the oral cavity. Candida fungi are present in the healthy oral microbiota, but conditions can make them pathogenic. Various antifungal drugs have been used to treat candidiasis, such as azole antifungals (ketoconazole, fluconazole) and polyene antifungals (nystatin, amphotericin B). However, several challenges have been observed with regard to the efficacy of drug treatment, such as resistance of fungal strains to antimycotics, patient compliance and adverse effects of synthetic drugs. Thus, the use of medicinal plants is a viable and promising alternative for the discovery of new phytopharmaceutical agents with great biological potential. Based on studies in the literature showing the physicochemical and ethnopharmacological characteristics of medicinal plant species, the aim of this research is to evaluate the antifungal activity of the hexanic extract of Psidium guineense (Myrtaceae). The study was carried out through in vitro tests in which the hexanic extract of Psidium guineense was used as a test substance against the fungal species Candida glabrata and Candida parapsilosis, which had been previously identified and maintained in Sabouraud dextrose agar (SDA) and Sabouraud dextrose broth (SSB) culture media. In addition, nystatin was used as the standard antifungal agent for the positive control. The broth microdilution technique was then used to determine the Minimum Inhibitory Concentration (MIC) of the hexanic extract of Psidium guineense. The MIC was read after 48 hours. As a result of this study, it was possible to identify that for both strains of the Candida genus, the hexanic extract of Psidium guineense showed a MIC value of more than 1024 µg/mL-1. This means that the test substance in question is ineffective against the strains of fungi tested using the methodology used, but further studies are needed to verify its antifungal potential against other strains of fungi.