ATIVIDADE ANTIMICROBIANA E ANTIBIOFILME DO EXTRATO ACETÔNICO DE Theobroma cacao L., VARIEDADE NACIONAL MODERNA, SOBRE CEPAS DE Pseudomonas aeruginosa E Staphylococcus aureus RESISTENTE À METICILINA (MRSA)

Abstract

Plants produce secondary metabolites with relevant pharmacological properties, standing out as alternatives in combating pathogenic microorganisms and biofilms. Theobroma cacao L. is a species widely studied for its biological activities, but there are still gaps in exploring the antimicrobial potential of the modern Nacional cocoa variety. Therefore, this study aims to report the phytochemical profile and evaluate the antibacterial and antibiofilm activities of the acetone extract of the leaves of T. cacao, a modern Nacional variety, against pathogenic strains of Pseudomonas aeruginosa and methicillin-resistant Staphylococcus aureus (MRSA). The bacterial strains were grown on Mueller-Hinton Agar and incubated at 37°C for 24 hours. The phytochemical test confirmed the presence of alkaloids, catechin tannins, flavonoids, and anthraquinones, in agreement with the literature for the species. Antimicrobial assays revealed greater activity of the extract against P. aeruginosa at a concentration of 1000 µg/ml, inhibiting 76.2% of bacterial growth and presenting an inhibitory concentration IC50 of 529 µg/ml. Regarding MRSA, 54.3% inhibition of bacterial growth was observed at a concentration of 1000 µg/ml, with an IC50 of 929 µg/ml, but with no effect on biofilm inhibition. Against P. aeruginosa, the extract showed mild antibiofilm activity, although without a dose-response relationship, possibly due to the molecular aggregation of secondary metabolites at higher concentrations, as reported in previous studies. These findings indicate that the acetone extract of the leaves of T. cacao, a modern Nacional variety, presented an active chemical profile, reinforcing the potential of T. cacao as a source of bioactive compounds and highlighting the need to fractionate the leaf extract for a better evaluation of its antibiofilm potential.