Antioxidant and antibacterial activities of the stem bark of Aspidosperma spruceanum Benth

The pharmacological activity of plants of the Apocynaceae family is mainly attributed to the presence of alkaloids. Aspidosperma spruceanum is a representative of this family, whose wood has been largely used in the construction industry. However, reports of its pharmacological and chemical properties are incipient. Therefore, this work aimed to investigate the antioxidant and antibacterial properties of extracts and fractions of this plant. After plant collection and identification, methanolic extract and fractions of the stem bark were prepared. Antioxidant activity was determined by •DPPH radical scavenging assay and total phenolics were estimated by reaction with Folin-Ciacalteau reagent. Minimum inhibitory and minimum bactericidal concentrations were estimated by the broth microdilution method against Staphylococcus aureus and Pseudomonas aeruginosa. The samples were also investigated for hemolytic activity. The phytochemical profile was determined by classical phytochemical tests. The methanolic extract of the bark showed bactericidal activity against S. aureus and bascteriostatic activity against P. aeruginosa. The hexane fraction obtained from crude extract fractionation acted as a bactericide against both strains. The ethanolic fractions of crude extract and dichloromethane and ethyl acetate fractions obtained from acid-base fractionation contained higher concentration of phenolics and, consequently, higher antioxidant activity in vitro. The analysis of the phytochemical profile indicated the presence of alkaloids, triterpenes and steroids in the samples. In conclusion, this article brings the first description of the antioxidant and antibacterial properties of A. spruceanum and preliminary chemical composition, and also values the components of the biodiversity of the state of Bahia not yet studied.