Effect of Tamarindus indica L. and Manihot esculenta Extracts on Antibiotic-resistant Bacteria

BACKGROUND: The chemical composition of plants used in traditional medicine exhibits biologically active compounds, such as tannins, flavonoids, and alkaloids and becomes a promising approach to treat microbial infections, mainly with drug-resistant bacteria. OBJECTIVE: The aim of the present study was to evaluate the hydroethanolic leaf extracts of Tamarindus indica (tamarind) and Manihot esculenta (cassava) as antimicrobial potential against Pseudomonas aeruginosa clinical isolated and Methicillin-resistant Staphylococcus aureus. MATERIALS AND METHODS: Hydroethanolic leaf extracts were prepared and characterized by high-performance liquid chromatography/diode array detection, Fourier transform infrared, 1,1-diphenyl-2-picrylhydrazyl, and ultraviolet-visible methods. The antimicrobial activity against four strains of clinical relevance was evaluated by the microdilution method at minimum inhibitory concentrations. RESULTS: Phenolic compounds such as flavonoids were detected in the plant extracts. T. indica extract at 500 μg/mL showed antimicrobial activity against S. aureus and P. aeruginosa; however, M. esculenta showed only activity against P. aeruginosa in this concentration. CONCLUSIONS: Our results suggested that polyphenols and flavonoids present in T. indica leaf extracts are a potential source of antimicrobial compound. The T. indica extract showed antibacterial activity against S. aureus and P. aeruginosa while M. esculenta had effect only on P. aeruginosa meropenem resistant. SUMMARY: Antibacterial effect of T. indica and M. esculenta leaf extract was evaluated. T. indica extract displayed activity against S. aureus and P. aeruginosa strains. M. esculenta showed effect on P. aeruginosa meropenem resistant. Abbreviations Used: BHI: Agar brain heart infusion, CAPES: Coordination for the improvement of higher education personnel, DPPH: 1,1-diphenyl-2-picrylhydrazyl, FAPITEC/SE: Foundation for support to research and technological innovation of the state of sergipe, FTIR: Fourier transform infrared spectroscopy, HPLC: High-performance liquid chromatography, KBr: Potassium bromide, MIC: Minimum inhibitory concentration, MRSA: Methicillin-resistant Staphylococcus aureus, RSC: Radical scavenging capacity, UV-vis: Ultraviolet-visible. [Image: see text]