Antibacterial properties of tropical plants from Puerto Rico.

In an effort to document the antibacterial properties of plants commonly used by the people of Puerto Rico, we studied the effects of 172 plant species, utilizing the disc diffusion method, against Escherichia coli and Staphylococcus aureus. The methanolic extracts of 14 species showed antibacterial activities during this preliminary screen. These positive plant extracts were tested successively over 15 additional species. The results showed that extracts from Citrus aurantifolia (Rutaceae), Citrus aurantium (Rutaceae), Punica granatum (Punicaceae), Phyllanthus acidus (Euphorbiaceae) and Tamarindus indica (Caesalpiniaceae) possess strong in vitro antibacterial activity against the bacteria tested.