Análise fitoquímica e antimicrobiana dos extratos vegetais de Vismia guianensis

Abstract

Plants are frequently used for their therapeutic and pharmacological properties, which are used to treat diseases and infections through teas, lozenges, ointments, decoctions, and baths. The Vismia guianensis specie has been reported in the literature to have various antibacterial and antifungal properties. This study aimed to perform phytochemical screening of leaves and stems from the municipality of Matinha, Maranhão, using two cold extraction methods: maceration and percolation; to evaluate the quantification of total phenol and flavonoid contents in methanolic solutions of the dried extracts; and to analyze the antimicrobial potential of the extracts. The phytochemical screening consisted of 11 qualitative tests. The determination of phenolic compounds and flavonoids was performed in triplicate, using aluminum chloride as the reagent and a reading at a wavelength of 429 nm. For the former, Folin-Ciocalteu and sodium carbonate were used as reagents, and readings were made at a wavelength of 765 nm Both analytical curves were constructed with six standards. Antimicrobial assays were performed against Staphylococcus aureus (ATCC 25923), Streptococcus pyogenes (ATCC 19615), Pseudomonas aeruginosa (ATCC 27853), and Escherichia coli (ATCC 25922). The assays were performed using the agar diffusion technique, minimum inhibitory concentration (MIC), and minimum bactericidal concentration (MBC). The results showed that the leaf extract by maceration presented a higher concentration of total phenols (165.95 ± 1.34 mg EAG/g) and the stem extract by percolation, a higher amount of flavonoids (66.82 ± 1.70 mg EQ/g) while the stem extract by maceration presented the lowest concentrations (MIC and MBC) for the tested strains