Scientific Research and Essays

  • Abbreviation: Sci. Res. Essays
  • Language: English
  • ISSN: 1992-2248
  • DOI: 10.5897/SRE
  • Start Year: 2006
  • Published Articles: 2740

Full Length Research Paper

Antibacterial activity of aqueous and ethanol extracts of the stem bark of Alstonia boonei and Morinda lucida

Patience O. Adomi
Biology Education Unit, Institute of Education, Delta State University Abraka, Nigeria.
Email: [email protected]

  •  Accepted: 17 November 2006
  •  Published: 30 November 2006



The water and ethanol extracts of the stem bark of two Nigerian medicinal plants, Alstonia boonei and Morinda lucida, used traditionally in treating several ailments were tested on clinical isolates of two Gram-positive and five Gram-negative bacteria. Ethanol extract of A.boonei was not active against any of the bacterial tested while the aqueous stem barks extracts of A. boonei and M. lucida were active. Ethanol stem bark extracts of M. lucida showed the best activity. The extent of the inhibition of bacteria was related to concentration of the plant extract, the solvent used for extraction and the organism tested. The minimum concentration of the active extract varied with the organism. Activities of the crude plant extracts were comparable to those of the standard antibiotics.


Key words: Medicinal plants, Alstonia bonei, Morinda Lucinda, Antibacterial activity, Nigeria.