To evaluate the antibacterial activity of eight plants against methicillin-resistant Staphylococcus aureus (MRSA), extended spectrum beta-lactamase and carbapenemase-resistant Enterobacteriaceae, which are the most prevalent causes of infections in inpatients.
The antibacterial activity was calculated based on the minimum inhibitory concentration using Mueller–Hinton broth in a microdilution method.
The best antibacterial activity, calculated as minimum inhibitory concentration values, against MRSA was shown by the Kaempferia pandurata (Roxb) (K. pandurata) extract (256 μg/mL) and the Senna alata (S. alata) extract (512 μg/mL). Phytochemical screening of dried S. alata leaf and its extract showed the presence of flavonoids, alkaloids, saponins, quinones, tannins and sterols, while dried K. pandurata and its extract only showed the presence of flavonoids and sterols/triterpenoids.
K. pandurata and S. alata have the potential to be developed as antibacterial agents, especially against MRSA strain, but further in vivo research and discovery of the mode of its action are still needed to shed light on the effects.
To investigate the antibacterial activities of crude ethanol extracts of 12 Philippine medicinal plants.
Crude ethanol extracts from 12 Philippine medicinal plants were evaluated for their antibacterial activity against methicillin-resistant Staphylococcus aureus, vancomycin-resistant Enterococcus, extended spectrum β-lactamase-producing, carbapenem-resistant Enterobacteriaceae and metallo-β-lactamase-producing Pseudomonas aeruginosa and Acinetobacter baumannii.
The leaf extracts of Psidium guajava, Phyllanthus niruri, Ehretia microphylla and Piper betle (P. betle) showed antibacterial activity against the Gram-positive methicillin-resistant Staphylococcus aureus and vancomycin-resistant Enterococcus. P. betle showed the highest antibacterial activity for these bacteria in the disk diffusion (16–33 mm inhibition diameter), minimum inhibitory concentration (19–156 μg/mL) and minimum bactericidal concentration (312 μg/mL) assays. P. betle leaf extracts only showed remarkable antibacterial activity for all the Gram-negative multidrug-resistant bacteria (extended spectrum β-lactamase-producing, carbapenem-resistant Enterobacteriaceae and metallo-β-lactamase-producing) in the disk diffusion (17–21 mm inhibition diameter), minimum inhibitory concentration (312–625 μg/mL) and minimum bactericidal concentration (312–625 μg/mL) assays.
P. betle had the greatest potential value against both Gram-negative and Gram-positive multidrug-resistant bacteria. Favorable antagonistic activities were also exhibited by the ethanol extracts of Psidium guajava, Phyllanthus niruri and Ehretia microphylla.