African Journal of

  • Abbreviation: Afr. J. Biotechnol.
  • Language: English
  • ISSN: 1684-5315
  • DOI: 10.5897/AJB
  • Start Year: 2002
  • Published Articles: 12294

Full Length Research Paper

Evaluation of antibacterial activity and acute toxicity of the hydroethanolic extract of Stachytarpheta angustifolia (Mill) Vahl.

Enwuru, N. V.1*, Ogbonnia, S. O.2, Nkemehule, F.2, Enwuru, C. A.3 and Tolani, O.1
  1Department of Pharmaceutical Technology and Pharmaceutical Microbiology, Faculty of Pharmacy, University of Lagos College of Medicine Campus, Idi-Araba, Lagos, Nigeria. 2Department of Pharmacognosy, Faculty of Pharmacy, University of Lagos College of Medicine Campus, Idi-Araba, Lagos, Nigeria. 3Microbiology Unit, Nigeria Institute of Medical Research, Yaba, Lagos, Nigeria.
Email: [email protected]

  •  Accepted: 13 May 2008
  •  Published: 03 June 2008



The aim of this study was to evaluate antibacterial activity, acute toxicity in mice and phytochemical profiles of hydroethanolic extract of Stachytarpheta angustifolia plant. The plant S. angustifolia has attracted the attention of the researchers because of its use as an anti-infection agent. The aqueous ethanol (80%) extract of the powdered dried whole plant was obtained by maceration. The bacteria organisms tested include Shigella dysentriae (ATCC 32412),Salmonella typhi (ATCC 213415), and the following clinical isolates: coagulase-negative StaphylococcusStaphylococcus aureus, Proteus mirabilis, Klebsiellaspecies and Escherichia coli. Susceptibility test, acute toxicity test and phytochemical screening of the plant extract were performed using standard procedures. The results showed that the extract had a good antibacterial activity against S. aureus, S. dysentriae, coagulase-negative Staphylococcus andProteus mirabilis. The minimum inhibitory concentration (MIC) was found to be between 11.6 and 14.0 mg/ml for the susceptible organisms. The extract exhibited minimum bactericidal concentration (MBC) of 150 mg/ml against S. dysentriae only while other susceptible tested bacteria strains required higher concentrations. The median acute toxicity value (LD50) of the extract was determined to be 8.721 g/kg body weight indicating the extract as being slightly toxic. The extract contained triterpenoid saponins as the major bioactive constituent.


Key words: Stachytarpheta angustifolia, acute, toxicity, antibacterial and phytochemical.