Planta Med 2004; 70(12): 1240-1242
DOI: 10.1055/s-2004-835860
Letter
© Georg Thieme Verlag KG Stuttgart · New York

Catechin Gallates Inhibit Multidrug Resistance (MDR) in Staphylococcus aureus

Simon Gibbons1 , Elisabeth Moser1 , Glenn W. Kaatz2
  • 1Centre for Pharmacognosy and Phytotherapy, The School of Pharmacy, University of London, London, U.K.
  • 2Division of Infectious Diseases, Department of Internal Medicine, School of Medicine, Wayne State University and the John D. Dingell Department of Veterans Affairs Medical Center, Detroit, Michigan, U.S.A.
Further Information

Publication History

Received: March 26, 2004

Accepted: July 10, 2004

Publication Date:
10 January 2005 (online)

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Abstract

Epicatechin gallate (1) and epigallocatechin gallate (2) were evaluated for their antibacterial and efflux inhibitory activity against a wild-type and three multidrug-resistant (MDR) strains of Staphylococcus aureus. Compound 2 was more active than 1 based on minimum inhibitory concentrations (MICs; 32 - 64 versus 64 - > 512 μg/mL, respectively). When incorporated into the growth medium at 20 μg/mL, both compounds exhibited a four-fold potentiation of the activity of norfloxacin against a norfloxacin-resistant strain of S. aureus overexpressing the NorA multidrug efflux pump. Against this strain 1 was moderately more potent than 2 as an inhibitor of ethidium efflux, but at ≤ 20 μM both compounds paradoxically stimulated efflux. This phenomenon has not been encountered previously in the analysis of inhibitors of multidrug efflux.

References

Dr. Simon Gibbons

Centre for Pharmacognosy and Phytotherapy

The School of Pharmacy

University of London

29-39 Brunswick Square

London WC1N 1AX

U.K.

Phone: +44-207-753-5913

Fax: +44-207-753-5909

Email: simon.gibbons@ulsop.ac.uk