ANTIBACTERIAL ACTIVITY OF Copaifera lucens CRUDE HYDROALCOHOLIC EXTRACT AND OLEORESIN AGAINST MULTIDRUG RESISTANT BACTERIA AND Copaifera lucens OLEORESIN GENOTOXICITY IN VIVO

Multidrug-resistant (MDR) bacteria are currently one of the most important threats to public health. Typically, MDR bacteria are associated with nosocomial infections. In this context, the discovery of new antimicrobials is an urgent matter. Natural products are a rich source of unknown molecules. Copaifera species are examples of such natural products. These species have been shown to display various pharmacological properties that could be useful in medicine. This work aims to evaluate the antibacterial activity of the crude hydroalcoholic extract of C. lucens leaves and of the oleoresin of C. lucens species against multidrug-resistant bacterial clinical isolates. To ensure that the use of C. lucens oleoresin is safe, this work also evaluates this oleoresin genotoxicity in vivo. The following bacterial clinical isolates were investigated: Acinetobacter baumannii, Enterococcus cloacae, Pseudomonas aeruginosa and Escherichia coli (species were isolated in Hospital Pio XII in Barretos/SP), Staphylococcus aureus, E. faecalis, and Klebsiella pneumoniae (species were isolated in the University Hospital of Ribeirao Preto/SP). The genotoxicity assay was conducted on the Swiss mice line Mus musculus. The antibacterial activity was evaluated in vitro through determination of the Minimum Inhibitory Concentration (MIC). Genotoxicity was assessed by the micronucleus assay performed on Swiss mouse bone marrow. C. lucens oleoresin presented MIC of 400 µg/mL against E. cloacae, E. faecalis, and S. aureus. C. lucens crude hydroalcoholic extract inhibited K. pneumoniae and P. aeruginosa growth; MIC was 400 µg/mL. For A. baumannii, both C. lucens crude hydroalcoholic extract and C. lucens oleoresin at 400 µg/mL inhibited bacterial growth. The micronucleus test did not evidence any genotoxicity at the evaluated C. lucens oleoresin concentrations (500, 250, and 125 µg/mL). In conclusion, C. lucens oleoresin and C. lucens crude hydroalcoholic extract exert moderate antibacterial activity against MDR bacteria, and the genotoxicity results demonstrate that the oleoresin does not pose any significant genotoxic risks.