INTRODUCTION:
Semi-synthetic dillapiole compounds derived from
Piper
aduncum
essential oil are used as alternative insecticides to
control insecticide-resistant
Aedes aegypti
. Thus, we aimed
to evaluate the genotoxic effects of semi-synthetic isodillapiole on the
nuclei of neuroblasts (larvae) and oocytes (females) and the mean
oviposition rates of the females over four generations (G
1
,
G
2
, G
3
, and G
4
) of
Ae.
aegypti
.
METHODS:
Larvae were captured in the city of Manaus, Amazonas state, Brazil, and
exposed to isodillapiole in bioassays (20, 40, and 60 µg/mL) and a negative
control (0.05% DMSO in tap water) for 4 h. The cerebral ganglia were
extracted from the larvae and oocytes from the adult females to prepare
slides for cytogenetic analysis. Breeding pairs were established and eggs
counts were quantified taken after the bioassays.
RESULTS:
The analysis of 20,000 interphase nuclei of neuroblasts and oocytes
indicated significant genotoxicity (micronuclei, budding, polynucleated
cells, and other malformations) compared to that of the control. Metaphasic
and anaphasic nuclei presented chromosomal breaks; however, no significant
variation and damage was observed in the negative control. A significant
reduction in mean oviposition rates was also recorded following exposure to
isodillapiole over the four generations (G
1
, G
2
,
G
3
, and G
4
).
CONCLUSIONS:
The toxic and genotoxic effects of isodillapiole on
Ae.
aegypti
were caused by reduced oviposition in the females and
nuclear abnormalities over the four generations of the trials. Further
studies are required, rather than our
in vitro
assays, to
verify the efficacy of exposure to this compound for controlling
Ae.
aegypti.