Antibacterial activity of ethanolic, methanolic and aqueous leaf extracts of Lantana camara from Ibanda, Western Uganda on archived Klebsiella pneumoniae and Streptococcus pneumoniae

Abstract

Current strategies to overcome the global problem of antimicrobial resistance include research in finding new antimicrobials from plants. Studies have documented that some plants contain bioactive compounds known as phytochemicals that possess preventative and curative properties. Notably, phytochemical composition and concentration vary according to soil properties and climatic conditions. Therefore, this study screened for the presence of phytochemicals and determined antibacterial activity of the aqueous, methanolic and ethanolic extracts of Lantana camara leaves from Ibanda District, South-Western, Uganda. The phytochemical screening of the plant leaf extracts was done by observing colour changes resulting from reactions between phytochemicals present and specific reagents. The antimicrobial susceptibility testing was done following the agar well diffusion method. Similarly, the potency of the aqueous, methanol and ethanol extracts involved measuring the activities of the three extracts at 15mg/ml, 20mg/ml and 30mg/ml according to agar-well diffusion method. This study revealed that the three Lantana camara extracts contained tannins, saponins, glycosides, steroids, flavonoids albeit at different intensities. Generally, all the three extracts had activity against Klebsiella pneumoniae and Streptococcus pneumoniae. However, ethanol extract exhibited better activity (mean zone of inhibition;16.36±0.82 mm) than aqueous extract (4.07±0.69 mm) and methanol extract (10.7±0.95 mm) for Streptococcus pneumoniae. Correspondingly, ethanol had mean zone of inhibition (13.20 ±0.68 mm) than methanol extract (8.44±0.95 mm) and aqueous extract (2.71±0.64 mm) for K. pneumoniae. This study has demonstrated the antibacterial activity of Lantana camara leaf extracts and therefore Lantana camara plant in our geographical setting can be a potential candidate in search for alternative antimicrobials. Thus, a comprehensive study should be conducted to quantify the phytochemical composition of different parts of the Lantana camara plant and evaluate the safety of the aqueous, methanolic and ethanolic extracts of the plant.