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Objective: To evaluate the antibacterial activity and neuroprotective capacity of the ethanolic and aqueous extracts of Tarenaya spinosa (T. spinosa) as well as to determine and quantify some of its polyphenols by high performance liquid chromatography with diode-array detection (HPLC-DAD). Methods: The bacterial Escherichia coli, Staphylococcus aureus and Pseudomonas aeruginosa strains, grown in Heart Agar Infusion, were tested. The drugs gentamicin, norfloxacin and imipenem were used to evaluate the modulating or antagonistic capacity of the T. spinosa extracts. The extract was analysed by HPLC-DAD to determine the main phenolic compounds. For the cell viability tests, individual heads of the Nauphoeta cinerea arthropod model were removed, homogenized in Trifluoromethyl ketone and centrifuged afterwards. Subsequently, 20 μL of NaNO
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Objective To identify the main chemical classes of compounds from aqueous extract of Enterolobium contortisiliquum (E. contortisiliquum) seed bark and to evaluate its antibacterial activity, as well as its potential to increase the activity of antibiotics against strains of Staphylococcus aureus, Pseudomonas aeruginosa and Escherichia coli. Methods Different classes of compounds in the aqueous extract of E. contortisiliquum were evaluated based on the visual changes in the coloration and the formation of precipitate after the addition of specific reagents. The antibacterial activity of the extract and its potential to increase of antibiotic activity of antibiotics drugs, gentamicin and norfloxacin was determined by using the microdilution method. Results Our results demonstrated that the following secondary metabolites were presented in E. contortisiliquum seed bark: flavones, flavonols, xanthones, flavononols, chalcones, aurones, flavones and catechins. The extract itself had very low antibacterial activity against all bacterial strains tested (MIC ≥ 1 024 μg/mL), but there was an increase in the antibiotic activity of gentamicin and norfloxacin when combined in the sub-inhibitory concentration (i.e., MIC/8). Conclusions Our data suggests that E. contortisiliquum seed bark may be an alternative source for new drugs with the potential to increase antibiotic activity against different strains of bacteria.