This study examined whether the antidermatophytic activity of essential oils (EOs) can be used as an indicator for
the discovery of active natural products against
Leishmania amazonensis. The aerial parts of seven plants were hydrodistilled.
Using broth microdilution techniques, the obtained EOs were tested against three strains of dermatophytes
(
Trichophyton mentagrophytes
,
Microsporum gypseum
and
Microsporum canis
). To compare the EOs antifungal and
antiparasitic effects, the EOs activities against axenic amastigotes of
L. amazonensis were concurrently evaluated. For
the most promising EOs, their antileishmanial activities against parasites infecting peritoneal macrophages of BALB/c
mice were measured. The most interesting antifungal candidates were the EOs from
Cymbopogon citratus
,
Otacanthus
azureus
and
Protium heptaphyllum
, whereas
O. azureus,
Piper hispidum and
P. heptaphyllum EOs exhibited the lowest
50% inhibitory concentration (IC
50) values against axenic amastigotes, thus revealing a certain correspondence between
both activities. The
P. hispidum EO was identified as the most promising product in the results from the infected
macrophages model (IC
50: 4.7 μg/mL, safety index: 8). The most abundant compounds found in this EO were sesquiterpenes,
notably curzerene and furanodiene. Eventually, the evaluation of the antidermatophytic activity of EOs appears
to be an efficient method for identifying new potential drugs for the treatment of
L. amazonensis.
