PHYTOCHEMICAL SCREENING AND ANTIOXIDANT PROFILE OF STEMBARK Extracts Piliostigma thonningii (Schum.)

Abstract

This study was conducted to examine the phytochemical screening and antioxidant activity of Piliostigma thonningii (Schum.) stembark. Extraction of the stembark was carried out using serial extraction starting with less polar to most polar solvent. The plant extracts (n-hexane, dichloromethane, ethyl acetate and methanol) were screened for the presence of phytochemicals using standard methods and their effect on 2,2-diphenyl-1-picryl-hydrazyl radical (DPPH) were used to determine their antioxidant activity. The results of the study showed that the ethyl acetate extract had highest antioxidant activity with IC50 of 0.58 mg/cm3 
which is greater than vitamin C with IC50 of 0.65 mg/cm3. Dichloromethane, methanol and hexane extracts showed lesser antioxidant values compared with vitamin C. The findings of this study suggest that the stembark extract of P. thonningii is rich in antioxidants and thus could be used as a potential source of natural antioxidants and therapeutic agents. Further studies should be carried out to investigate the bioactive compounds of this species and their possible characterization