UPLC/QTOF-MS/MS analysis and antibacterial activity of Commiphora leptophloeos (Mart.) J. B. Gillett against multi-drug resistant Staphylococcus aureus and Pseudomonas aeruginosa

Commiphora leptophloeos is known as “amburana-de-espinhos” or “Imburana” in Brazil. This plant species has been used as a material for combustion and construction, as well as medicinally. Traditional communities use this plant in the treatment of such as flu, urinary diseases and injuries, its pharmacological properties are attributed to the presence of tannins, saponins, flavonoids and alkaloids. Thus, this study aimed to evaluate the antimicrobial and antibiotic-modulating activity of the ethanolic extract of C. leptophloeos leaves. The chemical characterization of the extract was performed by UPLC-QTOF-MS/MS, confirming the presence of phenols and flavonoids of recognized pharmacological activity. To evaluate the antibacterial activity and ability of the extract to modulate the antibiotic activity of aminoglycosides towards resistant bacteria, the microdilution method was used in broth with determination of Minimum Inhibitory Concentration (MIC). The microorganisms used in the assays included standard and multi-drug resistant strains of Peudomonas aeruginosa and Staphylococcus aureus. The results were analyzed by ANOVA and Bonferroni’s posttest. The ethanolic extract of the leaves of Commiphora leptophloeos presented no clinically relevant intrinsic antibacterial activity with MIC ≥ 2048 μg/mL. However, modulation tests revealed that the extract significantly reduced the MIC values ​​of the antibiotics, indicating that the extract enhanced the action of the antibiotics against resistant microorganisms. In conclusion, C. leptophloeos has antibiotic-modulating potential. However, further research is recommended to better clarify the mechanism of action of the tested plant extract, guiding the development of new alternatives for the treatment of infections resistant to conventional therapies.