Activity profiles of fourteen selected medicinal plants from Rural Venda communities in South Africa against fifteen clinical bacterial species

Abstract

Fourteen plants used in traditional medicine in the Venda region of South Africa were screened for activity against
fifteen bacterial species. Methanol, acetone and hexane extracts and in some cases essential oils were tested
using the disc diffusion and the microdilution methods. Most of the extracts were active against at least one
bacterial species. Methanol and acetone extracts were the most active while Gram positive bacteria were the most
sensitive as compared to Gram negative bacteria. This study has revealed the strong in vitro activity of Syzigium
cordatum, Peltophorum africanum, Rhoicissus tridentata, Bridelia micrantha and Ximenia caffra against Gram
positive and Gram negative bacteria. Essential oils of Lippia javanica was also effective against most of the
bacterial species studied. However, Pouzolzia mixta and Mucuna coriaceae showed less activity. Some plants were
more active than commercial antibiotics. This study is the first to test the activity of the selected plants from the
Venda region against such number of bacterial isolates and justifies their use by local traditional healers. The
identification of the active components of the plants and the determination of the effect of these plants on the
immune system will give more information on their activity. Finally, these results may be of importance in
identifying candidate plants and essential oils for eventual drug design and other therapeutic purposes,
respectively.