Ethanolic and aqueous (cold and hot) extracts of Landolphiaowerrience root parts (whole-root, root-bark and root-wood) weretested for activity against ten bacterial strains using agar-well diffusion and macro-broth dilution methods, respectively. Theethanolic extracts of the whole-root and root-wood were active against 100 and 80% of the test organisms, respectively. Ethanolicand aqueous extracts of the root-bark were moderately active while the aqueous (cold and hot) extracts of the root-wood exhibited little or no activity. Out of the nine extracts prepared, 66.7% were active against Staphylococcus aureus ATCC 12600, 55.6%variously against each of Pseudomonas aeruginosa ATCC 10145 and local clinical isolates of P.aeruginosa, S. aureus, Escherichiacoli and Salmonella typhi, 44.4% against Proteus sp., 33.3% against Bacillus subtilis ATCC 6051 and 22.2% against E. coli ATCC 11775. The agar-well-determined MIC values for the ethanolic whole-root extract (0.78–50 mg/ml) were higher (indicating loweractivity) than the corresponding macro-broth-determined values (0.39–50 mg/ml) probably because of slow diffusion rates of theactive constituents of the extract in agar. On the other hand, the differences could be due to the effects of DMSO used to dissolvethe ethanolic extracts in the agar-well diffusion tests. Similar discrepancies in the MIC values detectable with the two test methodswere apparent in the root-wood extract and the control drug, Gentamycin, except that in the latter the agar-well-determined MICvalues (0.125–8.0 g/ml) were lower than the macro-broth-determined values (0.125–64 g/ml). The strong activity of the ethanolic extracts against known etiologic agents of diseases traditionally treated with L. owerrience root of similar preparationsprovides scientific justification for the use of the herb in ethnomedical practice in Nigeria.
Key words: Landolphiaowerrience, Root parts, Antibacterial activity, Ethnomedicine, Nigeria
EVALUATION OF EXTRACTS OF THE ROOT OF LANDOLPHIA OWERRIENCE FORANTIBACTERIAL ACTIVITY