Gebretsadik Tebabal Kebede* and Zelalem Abdisa Negero
The plant Calpurnia aurea has been used in Ethiopia as a folk remedy to treat diseases like malaria, rabies, stomachache, treatment of extoparasites and different diseases caused by bacteria and fungus. The present study aimed to screen phytochemicals and evaluate the in vitro antioxidant and antibacterial activities of the root bark extract of Calpurnia aurea. The root bark of Calpurnia aurea was collected from Wollega University compound, dried and extracted sequentially with hexane, ethyl acetate, acetone, and methanol. The preliminary phytochemical analysis was conducted using standard test methods. Phytochemical screening was found positive for alkaloids, Terpenoids, flavonoids, saponins, tannins, anthraquinones, and anthocyanins in the root bark even though different from extract to extract. Antibacterial activity was performed against Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, and Salmonella typhirium bacterial strains. Following the good activities of the extract the minimum inhibition concentration (MIC) have be performed and the methanol extract found to be effective at lower concentration (6.25mg/ml) for E. Coli whereas the ethyl acetate extract showed no or little activities below 100mg/ml except for E. Coli which inhibit at 25mg/ml. The ethyl acetate, acetone and methanol extract showed good antibacterial activities but the hexane extract didn’t show inhibition against tested bacterial strains. The MIC value also determined by serial dilution and the methanol extract was found effective at a lower concentration which is 6.25mg/ml in Escherichia coli, the ethyl acetates extract could not kill bacteria in dilution below 100mg/ml except Escherichia coli which inhibited at 25 mg/ml. Generally, the result obtained from this study is similar to the result reported in other parts of the plant species and support the medicinal values of the plant Calpurnia aurea. Thus the root bark of the plant was found to exhibit moderate antibacterial properties.