Authors : Rebecca Nalubega, John David Kabasa, Deo Olila and John Kateregga
Abstract: This study evaluated the antibacterial activity of aqueous extracts of eleven plants against gram positive (Staphylococcus aureus, Streptococcus faecalis) and gram negative (Escherichia coli and Salmonella typhimurium) bacteria using the agar well diffusion assay and tube dilution method. Qualitative tests were carried out to investigate the phytochemical composition for ether, ethanol and aqueous extracts of these plants. In general, gram-positive bacteria were more susceptible than gram-negative bacterial species. The aqueous extract of Moringa oleifera had activity on all the four bacteria species. The aqueous extracts of Persea americana had the lowest MIC (0.25 g mL-1) and therefore, the best activity on Salmonella typhimurium. Leonotis nepetifolia with MIC (0.25 g mL-1) and Lantana trifolia with MIC (0.15 g mL-1) had the lowest MICs and therefore, the best activity on Staphylococcus aureus. The most prominent phytochemicals of medicinal importance established in the extracts of most test plants were tannins, sterols, basic alkaloids and alkaloid salts. These results suggest that Moringa oleifera extracts could be of value in the discovery of compounds which may be effective in the treatment of a number of bacterial diseases. Similarly, Persea americana extracts may contain active compounds that could be used for treatment of salmonellosis while Leonotis nepetifolia and Lantana trifolia may contain compounds effective against staphylococcal infections. All the 11 tested plants contain phytochemicals with potentially beneficial therapeutic effects.
Rebecca Nalubega, John David Kabasa, Deo Olila and John Kateregga, 2011. Antibacterial Activity and Phytochemical Screening of Eleven Plants Used as Poultry Ethnomedicines in Southern Uganda. Agricultural Journal, 6: 303-309.