Phytochemical Screening, Antibacterial and Radical Scavenging Activities of Root Wood and Root Bark Extracts of Albizia schimperiana

Objective: Different parts of Albizia schimperiana are used for treatment of different types of diseases. In Ethiopia traditionally people use Albizia schimperiana to treat headache and other pains. In Tanzania the stem bark is used to treat warts, the leaf has shown significant antimicrobial and potential anti-helmintic activity. The main objective of the study was to identify the phytochemical constituents, and evaluate antibacterial and radical scavenging activities of root wood and root bark extracts of A. schimperiana. Method: The root of A. schimperiana was collected from east wollega zone, Nekemte town, in May 2018. The collected plant root was washed with distilled water and peeled so that the root wood and root bark were dried separately under shade at room temperature and ground in to powder using analytical mill. The bioactive constituents of the root of A. schimperiana were extracted through maceration technique using n-hexane, ethyl acetate, acetone, and methanol. The antibacterial assay was determined using disc diffusion method against four bacteria strains while the antioxidant activity of the plant extracts were investigated spectrophotometrically using DPPH. Result: The phytochemical screening revealed the presence of alkaloids, phenolic compounds, saponins, flavonoids, anthraquinones and terpenoids and absence of tannins and steroids in both root parts. The root extracts were active against all the tested bacterial strains. The root wood extracts of acetone and ethyl acetate demonstrated strong zone of inhibition against S. aureus (30mm) and E. coli (30 mm) at 100 mg/mL, as compared to the reference antibiotic gentamicin (20 mm). The methanol root wood extract of A. schimperiana has shown better DPPH radical scavenging activity at 1 mg/mL (89.8%) when compared to the methanol root bark extract (71.6%) at the same concentration. Conclusion: It can be concluded from this study that the root extracts of A. schimperiana owned many phytochemicals that exhibited promising antibacterial and antioxidant properties. Therefore, the root of A. schimperiana can serve as a potential source for development of new drugs as well as finding natural antioxidants that could assist the body in fighting disease like cancers.