Avaliação da atividade antifúngica ao extrato metanólico de Psidium guineense (Myrtacea) contra cepas de candida glabrata e candida Parapsilosis.

Abstract

Candidiasis is a very common fungal infection of the oral cavity, whose etiological factor is the proliferation and growth of microorganisms of the genus Candida, which already live in the oral environment in a commensal way, without causing any harm to the host, thus forming part of the healthy oral microbiota. In addition to the mouth, these fungi can also proliferate and colonize mucous membranes and skin, thus generating a systemic fungal disease. Various drugs with antifungal properties are used to treat these infections, such as ketoconazole, fluconazole, nystatin and amphotericin B. However, some factors have shown these drugs to be ineffective. One of them is the resistance of fungal strains to antimycotics, as well as patient compliance and the adverse effects that synthetic drugs cause. It is therefore necessary to look for alternatives, such as the use of medicinal plants, which has been a viable and promising way of discovering new phytopharmaceutical agents with great biological potential. Based on studies in the literature that show the physicochemical and ethnopharmacological characteristics of medicinal plant species, this research aimed to evaluate the antifungal activity of the methanolic extract of Psidium guineense (Myrtaceae). The study was carried out through an in vitro test in which the methanolic 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 Psidium guineense methanolic extract. After carrying out the tests and evaluating the results, it was noted that the MIC of the methanolic extract of Psidium guineense was higher than 1024 µg/mL-1 for the two strains tested. It can therefore be concluded that the methanolic extract of the Psidium guineense plant species did not inhibit fungal proliferation at the concentrations used in the technique. Thus, further studies (with different methodologies) are needed to compare the results obtained, and it may be possible to develop a new natural product, depending on the results, with efficient antifungal activity, so that it can be used among health technologies to combat fungal infections in order to mitigate the exponential increase in mycotic resistance, which has become an objection to successful drug treatment applied to dentistry.