Correlation of seizures and biochemical parameters of oxidative stress in experimentally induced inflammatory rat models

The role of oxidative stress in the pathogenesis of various conditions including epilepsy, inflammatory bowel disease and rheumatoid arthritis is evolving. The aim of this study was to find out the correlation between various inflammatory models with seizures and antioxidant parameters. Fifty-four male rats were divided into three groups of colitis, adjuvant arthritis and cotton wool granuloma (CWG). Each group had three subgroups of control, model and treatment. Thalidomide was used as treatment in colitis and arthritis group, whereas etoricoxib was used in CWG group. In colitis and arthritis groups, thalidomide was administered for 3 and 17 days, respectively, whereas etoricoxib was administered for 7 days in CWG group. At the end of treatment protocols, a subconvulsive dose of pentylenetetrazole (PTZ) (40 mg/kg i.p.) was injected intraperitoneally to note seizure onset and score. After confirming the presence of inflammation by morphological and histological studies, plasma and brain biochemical parameters of oxidative stress were estimated. The models of colitis, arthritis and CWG were effectively produced as evidenced by morphological scores (P < 0.001). Thalidomide reduced the morphological score (P < 0.002) and seizure grade (P < 0.001), whereas increased seizure onset (P < 0.001) in the arthritis group. There was an increase in malondialdehyde levels in the brain of thalidomide-treated groups (P < 0.002) and a significant decrease in superoxide dismutase (SOD) and glutathione peroxidase (GPx) levels. There was neither improvement in seizure nor any significant changes in lipid peroxidation and antioxidant enzyme levels in etoricoxib-treated group. Thalidomide was effective in reducing the extent of arthritis as well as reducing the seizure scoring and increasing seizure onset in the adjuvant arthritis group. As it increased lipid peroxidation and reduced SOD and GPx, further evaluation is necessary with respect to oxidative stress.