African Journal of
Biotechnology

  • Abbreviation: Afr. J. Biotechnol.
  • Language: English
  • ISSN: 1684-5315
  • DOI: 10.5897/AJB
  • Start Year: 2002
  • Published Articles: 12213

Full Length Research Paper

Aqueous Extracts of Pericopsis angolensis and Swartzia madagascariensis with High Antimicrobial Activities against Escherichia coli O157, Shigella spp. and Salmonella enterica subsp. enterica (Serovar typhi)

Chingwaru Constance
  • Chingwaru Constance
  • Biological Sciences Department, Faculty of Science and Engineering, Bindura University of Science Education, Zimbabwe.
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Tanja Bagar
  • Tanja Bagar
  • ICANNA – International Institute for Cannabinoids. Kodeljevo Castle, Ulica Carla Benza 16. SI-1000 Ljubljana, Slovenia.
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Chingwaru Walter
  • Chingwaru Walter
  • Biological Sciences Department, Faculty of Science and Engineering, Bindura University of Science Education, Zimbabwe.
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  •  Received: 11 May 2019
  •  Accepted: 29 July 2019
  •  Published: 30 September 2019

Abstract

This study determined the potential antidiarrhoeal potential of Pericopsis angolensis and Swartzia madagascariensis extracts against Escherichia coli O157, Shigella species and Salmonella Typhi. Extracts were obtained using the following methods: (i) hot water extraction (90°C) (LHWE), (ii) cold water extraction (CWED) and (iii) ethanolic extraction (EED). Antimicrobial effects of the extracts were determined using the well diffusion assay. Phytochemical analysis was performed using standard biochemical methods. The LHWE extracts exhibited significantly greater inhibition than CWED and EED extracts as follows: (i) P. angolensis bark extract at 0.8 mg/ml against Shigella spp. and (ii) P. angolensis bark extract at 1.6 mg/ml and S. madagascariensis bark extract at 1.6 mg/ml against S. Typhi. The aqueous methods largely resulted in P. angolensis and S. madagascariensis extracts rich in flavonoids, saponins and tannins. The aqueous extraction methods (CWED and LHWE) are therefore suitable to obtain extracts with high antimicrobial effects against E. coli O157, Shigella species and S. Typhi.

 

Key words: Antidiarrhoeal, phytochemicals, extraction, Pericopsis angolensis, Swartzia madagascariensis.