Phytochemical screening, antimicrobial and antioxidant activities of four Nigerian medicinal plants

By Ganiyat Kehinde OLOYEDE, Patricia Akpomedaye ONOCHA, Julius SOYINKA, Oluwaseyi OGUNTOKUN and Emmanuel THONDA


The antimicrobial activity of non-polar, moderately polar and polar extracts of the leaves of Alchornea laxiflora,  Cnidoscolus acontifolius (Euphorbiaceae), Newbouldia laevis, (Bignoniaceae) and Adansonia digitata (Bombacaceae) against Escherichia coli NCIB 86, Staphylococcus  aereus NCIB8588, Bacillus subtilis NCIB 3610, Pseudomonas aeruginosa NCIB 950 were investigated. There was generally no activity against the different strains of bacteria used. While the in vitro antioxidant activities of the hexane, ethyl acetate, butanol and aqueous extracts of the aerial parts of the plant materials determined by ferric thiocynate method showed that the species provided at least one fraction with highly promising antioxidant activity. However, phytochemical screening gave secondary metabolites that have been found to be of medicinal importance both in preventive and curative medicine.


Key Words : Medicinal plants, Phytochemicals, antimicrobial activity, antioxidant activity, ferric thiocynate.

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