Abstrato

Antimicrobial activity of Striga hermonthica

Elhadi N.Mahmoud, Hanan A.Wahab, Ibrahim M.Abu Alfutuh, Mohamed O.A.Elsheikh

Crude extracts from different morphological parts of Striga hermonthica (Scrophularaceae) were prepared and screened for antimicrobial activities. For antibacterial activity, the extracts are tested against the growth ofGram positive (Bacillus subtlis and Staphylococcus aureus) and Gram negative (Pseudomonas aeruginosa and Escherichia coli) bacteria. For antifungal activity, the extracts are tested against Aspergillus niger, A.flavus and Candida albicans. Most of the extracts showed good antibacterial activity against the growth of Gram positive bacteria, and some of them exhibited positive antibacterial activity against the growth of Gram positive as well asGramnegative bacteria; at concentrations of 1-5mg/ml extract. This as compared with 4 mg/mlAmpicillin or Neomycin. The petroleum ether extracts were found to be devoid of any antibacterial activity. The methanol and ethyl acetate extracts of the flowers showed a fungicidal activity against cultures of A. niger and A. flavus at concentration 1mg/ml.With C. albicans, the same extracts showed a fungistatic and fungicidal activity at concentrations 1 mg/ml and 5 mg/ml, respectively. This as compared with 3-5mg/mlKetaconazole.