Interação sinérgica entre o extrato etanólico das folhas de Cochlospermum regium e o composto hidrato de penta-O-galoil-β-D-glucose no controle de Staphylococcus aureus

• DOI: https://doi.org/10.22533/at.ed.3442405011

• Palavras-chave: Cochlospermum regium, compostos fitoquímicos, sinergismo, bioatividades.

• Keywords: Cochlospermum regium, phytochemical compounds, synergy, bioactivities.

• Abstract: Cochlospermum regium (Schrank) Pilg., known as " algodãozinho" or " algodão-do-campo", is a plant native to the Cerrado. Recent research has highlighted the effectiveness of the ethanolic extract of C. regium leaves against Staphylococcus aureus and identified the compounds with the highest detectability in the extract, namely methyl gallate, quercitrin and 1,2,3,4,6-pentagalloyl-glucose that present antimicrobial activity in the literature. Thus, taking into account the effectiveness of the C. regium extract against S. aureus and the possible interactions with isolated compounds that can enhance the antibacterial activity, the present study aimed to evaluate the synergism of the ethanolic extract of C. regium leaves and its main phytochemical components. The compounds methyl-3,4,5-trihydroxybenzoate (structural similarity with methyl gallate), penta-O-galloyl-β-D-glucose hydrate (structural similarity with 1,2,3,4,6-pentagalloyl-glucose) and quercitrin were commercially acquired. The extract was obtained by ethanolic extraction from C. regium leaves. The minimum inhibitory concentration (MIC) of the extract and compounds was evaluated against S. aureus supplied by the American Type Culture Collection (ATCC 25923) using the broth microdilution test with concentrations from 0.24 µg/mL to 250 µg/mL. Compounds without MIC results were excluded from synergistic evaluation. Synergism was determined by the checkerboard assay with concentrations of 0.97 to 125 µg/mL and 3.90 to 500 µg/mL for penta-O-galloyl-β-D-glucose hydrate and C. regium extract, respectively, against S. aureus. The results indicated that penta-O-galloyl-β-D-glucose hydrate presented an MIC of 31.25 µg/mL against S. aureus, also presenting bactericidal activity of 250 µg/mL. The checkerboard assay demonstrated a synergistic interaction between the extract and penta-O-galloyl-β-D-glucose hydrate, showing a 130-fold reduction in the MIC of penta-O-galloyl-β-D-glucose hydrate, indicating increased antibacterial activity when combined. The results obtained in this work, in addition to being unprecedented, are promising for future perspectives on the treatment of S. aureus infections.