In vitro activity of propyl gallate-azole drug combination against fluconazole- and itraconazole-resistant Candida albicans strains.
OBJECTIVE
The influence of an antioxidant, propyl gallate (PG), on the in vitro antifungal activity of itraconazole and fluconazole, was investigated to determine whether PG could increase the antifungal activity and reduce strain resistance.


RESULTS
Susceptibility tests were performed against azole-resistant isolates of Candida albicans by the microbroth dilution method in the presence of PG at 400 microg ml-1. PG-triazole combination brought about a marked reduction of inhibitory azole concentration. In particular, the MIC90 for itraconazole and fluconazole dropped from 1 microg ml-1 to 0.125 microg ml-1 and from > 64 microg ml-1-8 microg ml-1, respectively.


CONCLUSIONS
It is likely that more than one mechanism is involved in the above synergistic interaction, including effects of PG on ATP synthesis, thus reducing the ABC transporters activity, or an effect on the target of azole, i.e. the P-450 cytochrome.


CONCLUSIONS
The PG-triazole combination may have a role in future topical antifungal strategies but other studies are warranted.
D'Auria
F D
FD
Institute of Microbiology, Faculty of Pharmacy, University of Rome 'La Sapienza', Rome, Italy. martecca@libero.it
Tecca
M
M
Strippoli
R
R
Simonetti
N
N
D000935:Antifungal Agents / Q000494:pharmacology*; D000975:Antioxidants / Q000494:pharmacology*; D002176:Candida albicans / Q000187:drug effects*; D004347:Drug Interactions; D004352:Drug Resistance, Microbial; D015725:Fluconazole / Q000494:pharmacology*; D006801:Humans; D007093:Imidazoles / Q000494:pharmacology*; D017964:Itraconazole / Q000494:pharmacology*; D008826:Microbial Sensitivity Tests / Q000379:methods; D011435:Propyl Gallate / Q000494:pharmacology*
D000935:Antifungal Agents; D000975:Antioxidants; D007093:Imidazoles; D017964:Itraconazole; D011435:Propyl Gallate; D015725:Fluconazole