Detoxification and antioxidant function of liver of the marsh frog (Ranaridibunda) intoxicated with oil from Kenkiyak oilfield

Abstract

Detoxification and antioxidant functions of liver of marsh frog (Ranaridibunda) exposed to water-soluble fraction of oil from Kenkiyak oilfield
in concentrations of 0.05, 0.5 and 1% during 30 days were studied. Dosedependent increase of cytochrome P450 content (1.5-2 times) in comparison to intact animals (control), indicating the activation of detoxification
processes in liver of intoxicated frogs was observed. It was shown that the
growth of monooxigenases was accompained by enchancement of lipid
peroxidation processes: the content of MDA in liver of intoxicated marsh
frogs also rose dose-dependently 1.5-2 times(Р≤0,05)compared with control. Herewith, the content of reduced glutathione, one of the key substances of antioxidant and detoxification systems of the body, decreased
1.3-2 times (Р≤0,05) as a result of almost the same induction ofglutathioneS-transferase (1.3-2.1 times, Р≤0,05). It was found that activation of lipid
peroxidation in liver of intoxicated marsh frogs was caused by supression
ofactivity of catalase (1.2-1.5 times) and superoxide dismutase (1.1-1.4
times).On the basis of obtained results a conclusion about activation of detoxification functions and inhibition of antioxidant defence in liver of frogs,
leading to strengthening of oxidative stress in studied animalsas a result of
oil intoxication, was made. Accumulation of lipid peroxides in liver led to
disruption of adaptive reactions of intoxicated animals and development
of destructive and necrobioticchanges of hepatocytes.
Key words: marsh frog, liver, oil, cytochrome P450, malondialdehyde,
reduced glutathione, glutathione-S-transferase, catalase, superoxide dismutase.