Chemical contaminants resulting from anthropogenic
activities such as farming, manufacturing and mining processes remain the
ultimate drain of aquatic reservoirs. During the different processes carried
out by man, chemicals such as pesticides, heavy metals and polycyclic
hydrocarbons are produced and these chemicals find their way through runoff,
leaching and aerial drifts to aquatic bodies. The harmful effects of these
water contaminants are certainly at risk for freshwater biota and, therefore,
there is a need to control the effects of these chemical pollutants in order to
safeguard the health of aquatic life. In order to determine the potential of
using this enzyme mechanism as a biondictor of exposure to environmental
contaminants, we investigated the oxidative stress effects of chlorpyrifos and
lead on the freshwater snail Helisoma duryi. Snail classes were exposed to 5
ppb of lead acetate and 25 ppb of chlorpyrifos for 7 days, in which half of the
snails were slaughtered and half of the snails recovered in clean water and
were slaughtered for another 7 days. To test the activities of the following
antioxidant enzymes, superoxide dismutase, catalase, glutathione peroxidase,
glutathione S-transferase, and diphosphotriphosphodiaphorase, post
mitochondrial fractions were used. Both contaminants increased the activities
of all antioxidant enzymes, suggesting the snail's defense mechanism to fight
oxidative stress due to the chlopryrifos organophosphate and metal pollutant
lead. The substantial recovery of the snails' antioxidant protection mechanism
permitted to recover in clean water has been demonstrated by a decreased
alteration of the snails' antioxidant enzyme activities permitted to recover
for 7 days. This supports the need to mitigate the exposure of marine biota to
chemical contaminants and to restore contaminated water bodies if they are
polluted, in order to safeguard the health of aquatic organisms.
Author (s) Details
Norah Basopo
Department of Applied Biology and Biochemistry,
National University of Science and Technology, P.O. Box AC 939, Ascot,
Bulawayo, Zimbabwe.
Thamsanqa Ngabaza
Department of Applied Biology and Biochemistry, National University of
Science and Technology, P.O. Box AC 939, Ascot, Bulawayo, Zimbabwe.
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Book :- https://stm.bookpi.org/CACB-V1/issue/view/12
