Synergistic interactions between plant extracts, some antibiotics and/or their impact upon antibiotic-resistant bacterial isolates

  • MEA Dawoud
  • YA Mawgoud
  • TM Gouda Dawoud


In this study, the antibacterial activities of medicinal plant extracts [of Rehum palmatum (R), Cassia angustifolia (C), Glycyrrhiza glabra (G), Chichorium intybus (Ch), and Matricaria chamomilla (M)], on antibiotic- resistant isolates (Staphylococcus aureus and Alcaligenes xylosoxidans) collected from clinical samples, pharmaceutical products, and different hospital water drains was detected (single, combined extract). This investigation shows that the extracts of G. glabra, R. palmatum and C. angustifolia and their combination with the selected antibiotic, variously inhibited the growth of the bacterial isolates. The methanol extraction ingredients recorded the maximum Inhibition Zone Diameter (mm IZD); 18.8/R, 12.6/C and 12.8/G plants. Prominent synergism occurred between plants extract mixture and Gentamycin, Ceftasidine, Tobramycin, Cefoperazone and Spictinomycin (GD) antibiotics. Rehum plant extract was the most potent antibacterial agent against S. aureus and A. xylosoxidans, especially when extracted with methanol solvent.

Keywords: Synergism, antagonism, Glycyrrhiza glabra, Rehum palmatum, Cassia angustifolia, antibioticresistant bacteria, Staphylococcus aureus, Alcaligenes xylosoxidans, hospitals drain, clinical samples, volatile oils, total flavonoids

African Journal of Biotechnology Vol. 12(24), pp. 3835-3846

Author Biographies

MEA Dawoud
Botany Department, Faculty of Science, Cairo University, Giza 12613, Egypt
YA Mawgoud
Botany Department, Faculty of Science, Cairo University, Giza 12613, Egypt
TM Gouda Dawoud
Phytochemistry Department, Applied Research Center for Medicinal Plant, Ministry of Health, National Organization for Drug Control and Research (NODCAR), Egypt

Journal Identifiers

eISSN: 1684-5315