Citral, the main constituent of lemongrass (
Cymbopogon citratus
) essential oil, was added to
Trypanosoma cruzi
cultures grown in TAU3AAG medium to observe the effect on the epimastigote-to-trypomastigote differentiation pro-
cess (metacyclogenesis). Our results showed that citral (20 μg/mL) did not affect epimastigote viability or inhibit the
differentiation process. Concentrations higher than 60 μg/mL, however, led to 100% cell death (both epimastigote
and trypomastigote forms). Although epimastigotes incubated with 30 μg/mL citral were viable and able to adhere to
the substrate, we observed around 50% inhibition in metacyclogenesis, with a calculated concentration that
inhibited metacyclogenesis by 50% after 24 h (IC
50
/24 h) of about 31 µg/mL. Treatment with 30 μg/mL citral did not hinder
epimastigote multiplication because epimastigote growth resumed when treated cells were transferred to a drug-
free liver infusion tryptose culture medium. Metacyclogenesis was almost totally abolished at 40 μg/mL after 24 h of
incubation. Furthermore, the metacyclic trypomastigotes obtained in vitro were similarly susceptible to citral, with
an IC
50
/24 h, concentration that killed 50% of the cells after 24 h, of about 24.5 µg/mL. Therefore, citral appears to
be a good candidate as an inhibitory drug for further studies analyzing the
T. cruzi metacyclogenesis process.
