Aim: Oxidative stress is a state in which there is disequilibrium between pro-oxidant processes and the antioxidant defense system in favor of the former and occurs as a consequence of increased production of free radicals or when the antioxidant defense system is inefficient or a combination of both events. A disturbance in the antioxidant defense system, including antioxidant enzymes superoxide dismutase (SOD) and glutathione peroxidase (GSHPx), due to free radical-induced oxidative injury has also been implicated in various neuropsychiatric disorders. Hence the role of these antioxidant enzymes and the changes in their level in blood and correlation with oxidative stress and the overall mechanism of defense were studied in a common psychiatric illness, schizophrenia.
Materials and methods: Fifty subjects of either sex ranging in age from 18 to 60 years, divided into two age groups (< 40 years and >40 years), diagnosed for schizophrenia; and 50 age- and sex-matched normal subjects as controls were included in the study. Blood samples were collected for the determination of malondialdehyde (MDA), superoxide dismutase (SOD), glutathione peroxidase (GSHPx), and reduced glutathione (GSH).
Results: Significantly lower levels of the two antioxidant enzymes were found in schizophrenics compared to normal controls, with an increased oxidative stress as indicated by high blood MDA levels. The condition worsened with advancing age, smoking, among literate masses, and in chronic schizophrenics; whereas gender did not show any effect.
Conclusion: It can be concluded that an imbalance in the antioxidant defense system, along with enzymatic antioxidants, occurs in schizophrenia due to the persistent oxidative stress. Modern life style perhaps also contributes to the condition.
Keywords: Antioxidant enzymes; GSHPx; MDA; SOD; oxidative stress; schizophrenia.