Antibacterial effect of the hydroalcoholic extract of Mauritia flexuosa leaves on gram-negative and gram-positive bacteria

Abstract

Background: Plant-derived compounds are sometimes used as substitutes for pharmaceuticals. Mauritia flexuosa is a palm tree that is widely distributed in South America, especially in the Amazon region. The San Martín region of Peru, in which this species of the Arecaceae family is found, has great biological diversity and there is economic potential in the utilization of natural resources in the region. Methods: In this study, the antibacterial effect of the hydroalcoholic extract of Mauritia flexuosa leaves was evaluated for gram-positive bacteria Staphylococcus aureus ATCC 25923 and Bacillus subtilis ATCC 6633 and gram-negative Escherichia coli ATCC 25922, Pseudomonas aeruginosa ATCC 27853 and Salmonella enterica subsp. enterica ser. Typhi ATCC 11011. Mauritia flexuosa leaves were used to prepare concentrations of 10, 20, 40 and 60mg/ml. Phytochemical analysis was performed to identify secondary metabolites in the plants. For the experiment, 10 Mueller-Hinton agar plates were prepared and 1ml of bacterial inoculum, standardized to 0.5 McFarland, was added to each plate. The hydroalcoholic extract was added via the diffusion method, making five holes of 5mm each (four with extract concentrations and one with distilled water as a control group), and the plates were incubated for 24 hours at 36°C. The inhibition halo was measured in mm using a digital vernier caliper. Results: For gram-negative bacteria, an antibacterial effect was demonstrated for Pseudomonas aeruginosa only, at an extract concentration of 60mg/ml, with an inhibition halo of 14.8 mm. For gram-positive bacteria Baccillus subtilis and Staphylococcus aureus, an antibacterial effect was demonstrated at an extract concentration of 60mg/ml, with inhibition halos of 13.2mm and 15.4mm in diameter, respectively. Conclusion: It can be concluded that the hydroalcoholic extract of Mauritia flexuosa does not inhibit bacterial growth for gram-negative bacteria Salmonella Typhi and Escherichia coli.