Lippia alba (Mill.) N. E. Brown (Verbenaceae), commonly known as "erva cidreira", is widely distributed throughout Brazil and is used in folk medicine as an analgesic, anti-inflammatory, cold remedy, as well as to reduce fevers and treat hepatic afflictions. Crude extracts of L. alba were prepared from plants cultivated in the medicinal garden of the Laboratório de Fitoterapia of the Empresa Pernambucana de Pesquisa Agropecuária (IPA), State of Pernambuco, Brazil, using standard techniques to test their in vitro antibacterial activity using the paper disk-diffusion method. The minimum inhibitory concentration (MIC) was determined for those extracts demonstrating the highest activity. The results demonstrated that the chloroform, acetone and ethanol extracts of root material were active against the growth of Staphylococcus aureus, Micrococcus luteus, Bacillus subtilis, Mycobacterium smegmatis, Candida albicans and Monilia sitophila, while the hexane, ethanol and methanol extracts of leaves inhibited the growth of S. aureus, M. luteus, B. subtilis, M. smegmatis and M. sitophila. The lowest inhibitory concentration (MIC = 31.2 µg/mL) was obtained with the chloroform root extract against B. subtilis and M. luteus.
Antimicrobial activity; Lippia alba; medicinal plant