This study evaluated the effect of vitamins
with antioxidant activity on the effect of
Dichlorvos (2, 2-dichlorovinyl dimethyl phosphate),
an organophosphorus compound used
in pest control on mammalian organs.
Literature is scanty on the histopathological
effects of inhalationally administered dichlorvos,
especially of the formulations used in
Nigeria. The objective of the study is to evaluate
these effects on vital organs, with a view
to proffering solutions to ameliorate the
effects.
Fifty Wistar male rats were divided into 10
groups of 5 rats each. A group served as control,
while the other groups were exposed to
dichlorvos for between 1-6 weeks in a poorly
ventilated compartment. The last three
groups in addition to dichlorvos exposure
received supplementation with vitamin C, E
or red palm oil (RPO). Exposure to dichlorvos
was done for 4 hours daily. At completion of
exposure, animal tissue was processed by the
routine method for paraffin wax and stained
sections were examined under the light microscope.
Histopathological studies of the lung
showed extension in the width of bronchial
associated lymphoid tissue (BALT), mild generalized
congestion of the peri-bronchiolar
and inter-alveolar septum as compared with
the control. These observations were much
reduced in the vitamin-treated groups.
Similarly, histopathological studies of the
liver showed diffuse vacuolar degeneration of
hepatocytes with peri-portal cellular infiltration
by mononuclear cells, vacuolar degeneration
and necrosis of hepatocytes when compared
with the normal. These changes were
significantly reduced in the vitamin-supplemented
groups.
In conclusion, inhalationally absorbed
dichlorvos caused histopathological changes
in the lung and liver of rats, but these were
ameliorated by co-treatment with vitamin
supplementation. The changes provide the
histological basis for further work and counselling
on careful use of dichlorvos for domestic
and agriculture, especially in enclosed
areas.