Résumé:
The antifungal potency of the essential oils of
Rhanterium adpressum was evaluated against four mycotoxigenic
strains of the genus Fusarium. The essential oils
were obtained, separately, by hydro-distillation of the aerial
parts of R. adpressum (leaves and flowers). The parts were
collected during the period of bloom (3 months) for 3 years.
The GC–MS analysis revealed thirty-six compounds for the
essential oils, divided into four classes of chemical compounds,
with variable percentages according to the month
of extraction. The monoterpene hydrocarbons form the
main class in these oils. On the other hand, the highest
percentages of the oxygenated compounds are observed in
the samples collected during the month of May. The direct
contact method was used to evaluate the antifungal activity
of the essential oils. The activity can be attributed to their
relatively high composition of oxygenated monoterpenes.Flowers extract showed strong inhibitory activity, with very
interesting concentrations of IC50 and MIC for both tests
on solid and liquid medium. The effect of these oils on the
production of type B trichothecenes (TCTBs) was evaluated,
showing a significant inhibitory effect on TCTBs production,
for both extracts (leaves and flowers). The rates of
inhibition were 66–97 and 76–100% of FX, 3-ADON and
15-ADON, respectively. The inhibition of fungal biomass
and the production of TCTBs depended on the used concentration
of the essential oils. These results suggest that
the essential oils from R. adpressum are able to control the
growth of the tested strains and their subsequent production
of TCTB mycotoxins.
