Isoflavones as potentiators of antibacterial activity

J Agric Food Chem. 2003 Sep 10;51(19):5677-9. doi: 10.1021/jf0302714.


Isoflavones isolated from Lupinus argenteus were found to potentiate the antibacterial activity of alpha-linolenic acid, also found in the same plant. The isoflavones also potentiated the activity of the natural plant antibiotic berberine and the synthetic fluoroquinoline antibiotic norfloxacin. The isoflavones increased the uptake of berberine into Staphylococcus aureus cells, indicating that they may be inhibiting a multidrug resistance pump (MDR). Thus, L. argenteus contains a weak antibacterial and also MDR pump inhibitors, which increase its potency.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • ATP Binding Cassette Transporter, Subfamily B / antagonists & inhibitors
  • Anti-Bacterial Agents / pharmacology*
  • Berberine / metabolism
  • Berberine / pharmacology
  • Drug Synergism
  • Isoflavones / pharmacology*
  • Lupinus / chemistry*
  • Norfloxacin / pharmacology
  • Plant Leaves / chemistry
  • Plant Stems / chemistry
  • Staphylococcus aureus / drug effects
  • Staphylococcus aureus / metabolism
  • alpha-Linolenic Acid / pharmacology


  • ATP Binding Cassette Transporter, Subfamily B
  • Anti-Bacterial Agents
  • Isoflavones
  • Berberine
  • alpha-Linolenic Acid
  • Norfloxacin