Extracts of Leaves of Ficus auriculata Lour.: Antioxidant, Antimicrobial and Phytotoxic Activity

摘要

Ficus auriculata Lour. is a tree of the genus Ficus. The aim of this study was to obtain the total phenolic compounds; and to determine the antioxidant (DPPH), antimicrobial (diffusion disc and Minimal Inhibitory Concentration) and phytotoxic activity (in cucumber - Cucumis sativus L.) of the extracts. Five extraction methods were used to obtain extracts of young and mature leaves of F. auriculata: water/ethanol (M1), water/ethanol/ultrasound (M2), water/ethanol/cellulase complex (M3), water (M4) and water/cellulase complex (M5). The phenolic content for extracts of young leaves was of 30.22 ± 2.99 mg GAE.g-1 dry sample (M1), 35.22 ± 0.53 mg GAE.g-1 dry sample (M2) and 28.90 ± 0.57 mg GAE.g-1 dry sample (M3) and for the mature leaves of 24.42 ± 0.04 mg GAE.g-1 dry sample (M2) and 17.13 ± 4.69 mg GAE.g-1 dry sample (M1). For the antioxidant activity, the lowest values of IC50 (or higher antioxidant activity) occurred for the extracts of young and mature leaves obtained by the M2. The extracts were able to inhibit all the evaluated bacteria, presenting MICs in the range of 21.60–90.32 μg.ml-1 for the Escherichia coli, 21.60-188.85 μg.ml-1 for the Salmonella enteritidis, 64.22-188.85 μg.ml-1 for the Staphylococcus aureus and 76.31-87.82 μg.ml-1 for the Listeria monocytogenes. The extracts of young and adult leaves presented herbicide potential, occurring suppression of the growth of cucumber plants. The use of the extract obtained in M3 led to the death of the plants. Extracts of F. auriculata presented antioxidant and antimicrobial activities, which agree with previous studies linking phenolic compounds to these properties.