Investigação do potencial antifúgico de Sida planicaulis sobre fungos filamentosos potencialmente patogênicos.

Abstract

Sida planicaulis, popularly known as "broom", is a herbaceous plant species, very common in Curimataú Paraibano, but little studied in relation to its antimicrobial potential. Taking into account this fact, this work aimed to evaluate the antifungal activity of crude, hexanic, chloroformic, aceto-ethylic and hydroalcoholic extracts of said plant on the filamentous fungi Rhizopus oryzae, Exophyala werneckii, Aspergillus niger, Aspergillus flavus, Trichophyton mentagrophytes, Cladosporum 2B3 e Microsporum canis. The antifungal activity was initially verified by the diffusion technique in Agar. Suspensions prepared in 0.85% saline (106 CFU / mL) were seeded on Sabouraud-Dextrose Agar plates on which sterile paper discs containing the plant products were dispensed. Incubation was carried out in a bacteriological oven at 28ºC for 7 to 15 days. The antifungal activity was evaluated by measuring the values of the inhibition halos, after which the determination of the Minimal Inhibitory Concentration (MIC) by the microdilution technique was performed only with the products that presented antifungal activity in the microbiological screening, all tests were performed in triplicate. The results showed antifungal activity against the microorganism Trichophyton mentagrophytes, the values of the inhibition halos varied between 15 and 36 mm, however the extracts showed no antifungal activity against the other species. MIC values were 625 μg/mL for the crude ethanolic extract and the chloroform phase, the hexane and acetophenyl phase with 2,500 μg/mL and the hydroalcoholic phase with 10,000 μg/mL, but none showed to be more active than the control positive ketoconazole (CIM = 1 μg/mL). It can be concluded that the extracts used of the species Sida planicaulis have an inhibitory effect against the fungus T. mentagrophytes, but did not obtain adequate concentrations for the development of a new antifungal.