Research in Pharmaceutical Biotechnology

  • Abbreviation: Res. Pharm. Biotech.
  • Language: English
  • ISSN: 2141-2324
  • DOI: 10.5897/RPB
  • Start Year: 2009
  • Published Articles: 42

Full Length Research Paper

Evaluation of in vitro antimicrobial effect of combinations of erythromycin and Euphorbia hirta leaf extract against Staphylococcus aureus

Michael Adikwu
  • Michael Adikwu
  • Department of Pharmaceutics, University of Nigeria, Nsukka, Enugu State, Nigeria.
  • Google Scholar
Clement Jackson
  • Clement Jackson
  • Department of Pharmaceutics and Pharmaceutical Technology, University of Uyo, Awka Ibom State, Nigeria.
  • Google Scholar
Charles Esimone
  • Charles Esimone
  • Department of Pharmaceutics, University of Nigeria, Nsukka, Enugu State, Nigeria.
  • Google Scholar

  • Article Number - 27B59FD456
  • Vol.2(2), pp. 022-024 , April 2010
  •  Accepted: 29 January 2009
  •  Published: 30 April 2010



The in vitro combined effects of erythromycin and methanol extract of leaves ofEuphorbia hirta against clinical isolates of Staphylococcus aureus were investigated using the Checkerboard technique. The organism was susceptible to the extract with MIC of 25 mg/ml, while erythromycin had MIC of 0.005 mg/ml. The research aims to investigate the possible interaction that may exist when standardize herbal drugs are combined with synthetic antimicrobials. Previously, stock solutions of both the extract and erythromycin were prepared in appropriate volume of dimethylsulphoxide and water respectively to get a final concentration of 50 mg/ml each. Minimum inhibitory concentration was determined by method of serial dilution while interaction study was carried out according to the continuous variation checkerboard method. Upon combination, some ratios showed synergistic (9:1, 8:2, 7:3, 6:4, 3:7, 2,8, 1:9) while others indicated indifference (5:5, 4:6) activities against the isolates. These results indicate that some combinations of the extract with erythromycin could be synergistic in activity for some ratio combinations and indifferent for some others.


 Key words: In vitro, erythromycin, Euphorbia hirta, staphylococcus aureus, MICcheckerboard.