RESUMO
Objective: To investigate the antibacterial activities of crude ethanol extracts of 12 Philippine medicinal plants. Methods: 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. Results: 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-c-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. Conclusions: 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.
RESUMO
OBJECTIVE@#To determine the antibacterial, antifungal, antiprotozoal, cytotoxic, and phytochemical properties of ethanol extracts of leaves of Voacanga globosa (Blanco) Merr. (V. globosa).@*METHODS@#The extracts were tested against bacteria and fungus through disc diffusion assay; against protozoa through growth curve determination, antiprotozoal and cytotoxicity assays.@*RESULTS@#The extract revealed antibacterial activities, inhibiting the growth of Staphylococcus aureus, Bacillus cereus, Pseudomonas aeruginosa, Micrococcus luteus, and Salmonella typhimurium. Antifungal assay showed that it inhibited Candida albicans. The antiprotozoal assay against Trichomonas vaginalis and Entamoeba histolytica showed that V. globosa can inhibit the parasites, wherein the action can be comparable to metronidazole. With the in situ cell death detection kit, Trichomonas vaginalis and Entamoeba histolytica exposed to V. globosa leaf extract was observed to fluoresce simultaneously in red and yellow signals signifying apoptotic-like changes. Preliminary phytochemical screening revealed the chemical composition of plant extract containing alkaloids, saponins, 2-deoxysugars, and hydrolysable tannins.@*CONCLUSIONS@#Thus, this study provides scientific evidence on the traditional use of V. globosa leaf extract in treating microbial diseases. Further, the leaf extract can possibly be used to produce alternative forms of antimicrobials.