Propyl paraben induces potassium efflux in Escherichia coli.
OBJECTIVE
Parabens are currently used as antibacterial preservatives in pharmaceutical, cosmetic and food products but there are no precise data concerning their activity on bacterial membranes.


METHODS
We analysed the cytoplasmic potassium release during propyl paraben addition by using a selective electrode. Various conditions were assayed to investigate the bacterial paraben susceptibility. We compared the activity of propyl paraben with the activities of colicin A and polymyxin B.


RESULTS
Propyl paraben induced potassium efflux that was related to the porin expression in the bacterial outer membrane. In addition, the presence of spermine, previously described as an efficient OmpF channel-blocker, protected susceptible cells against paraben activity.


CONCLUSIONS
Propyl paraben induced potassium release in susceptible Escherichia coli cells similar to that observed with polymyxin B. Moreover, this efflux depended on porin channel activity. This permeabilizing effect is probably related to antibacterial properties of paraben molecules.
Bredin
Jérôme
J
Enveloppe Bactérienne, Perméabilité et Antibiotiques, IFR 48, Faculté de Médecine, Université de la Méditerranée, 27 Boulevard Jean Moulin, 13385 Marseille Cedex 05, France.
Davin-Régli
Anne
A
Pagès
Jean-Marie
JM
D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D004926:Escherichia coli / Q000187:drug effects* / Q000378:metabolism; D010226:Parabens / Q000494:pharmacology*; D018272:Porins / Q000502:physiology; D011188:Potassium / Q000378:metabolism*
D000900:Anti-Bacterial Agents; C109237:OmpF protein; D010226:Parabens; D018272:Porins; D011188:Potassium; C006068:propylparaben