ANTIBACTERIAL ACTIVITY OF EAST-AFRICAN MEDICINAL-PLANTS

In an ethnopharmacological survey, extracts of the six East African me dicinal plants Entada abyssinica (stem bark), Terminalia spinosa (youn g branches), Harrisonia abyssinica (roots), Ximenia caffra (roots), Az adirachta indica (stem bark and leaves), and Spilanthes mauritiana (ro ots and flowers) were tested against 105 strains of bacteria from seve n genera (Staphylococcus, Enterococcus, Pseudomonas, Escherichia, Kleb siella, Salmonella, Mycobacterium). The minimum inhibitory concentrati on reached by 50% (MIC50%) and 90% (MIC90%) of the strains for the ext racts of E. abyssinica, T. spinosa, X. caffra, and A. indica (stem bar k) ranged from 0.13-8 mg/ml and from 0.5 to > 8 mg/ml, respectively. T heir minimum bactericidal concentration by 50% (MBC50%) and MBC90% wer e all between 0.5 and > 8 mg/ml. H. abyssinica, A. indica (leaves), an d S. mauritiana (roots and flowers) had MIC and MBC values greater tha n or equal to 8 mg/ml. Mycobacteria were not inhibited at extract conc entrations of 0.5-2 mg/ml. It is concluded that plant extracts with lo w MIC and MBC values may serve as sources for compounds with therapeut ic potency. (C) 1998 Elsevier Science Ireland Ltd.