Antimicrobial activity of Amazonian plant species against the causative agents of secondary infection in snakebites

Riverine communities in the Brazilian Amazon region use a variety of plants to treat snakebites. These plants can be effective against secondary infections, one of the main complications of snakebites. The aim of this study was to determine whether plants traditionally used to treat snakebites in the Brazilian Amazon may also have antimicrobial and antioxidant activities, and if so, which classes of chemicals may be responsible for these activities. Aqueous extracts of nine plants were tested in microdilution assays and the more active were prepared using solvents (hexane, methanol and water) and decoction, and nine assays were performed. Assays to determine the antioxidant activity of the most active species were carried out, as well as phytochemistry studies to determine the active components of this species. Bellucia dichotoma exhibited the greatest antimicrobial potential, particularly the hexane, methanol and decoction extracts. In comparative TLC, extracts of this species showed characteristics of terpenoids, compounds with double bonds and flavonoids. In 1H NMR, characteristic signals of sterols such as β-sitosterol, stigmasterols or triterpenes were observed, as well as signals indicating the presence of aromatic hydrogens, characteristic of aromatic substances, and sugars. The methanol extracts and decoction were considered active in the antioxidant assay.