[doi: 10.5505/2017ichc.PP-34]

Investigation of protective effect of agomelatine in the brain cortex of rats exposed to high light stress: A histological and immunohistochemical study

Erdem Toktay, Elif Polat, Jale Selli, Tugba Bal, Nurhan Akaras
Department of Histology and Embryology, Ataturk University, Erzurum, Turkey

IIntroduction & OBJECTIVES: High light stress is known to cause oxidative stress damage in various organs in living organisms. Studies in the literature have shown that oxidative stress causes damage in tissues such as brain, liver, lung. Agomelatine, a good antioxidant, has been shown to reduce oxidative stress damage in recent studies. In this study, we aimed to demonstrate the protective effect of agomelatine against oxidative stress damage in the cerebral cortex of rats exposed to high light stress.
Materials & METHODS: 30 female Sprague Dawley rats, randomly divided into 5 groups, were used in the present study. The groups were Control group, 40mg/kg Agomelatine (AG) group, light stress (LS) group, LS + 10mg/kg AG group, LS + 40mg/kg AG group. The rats were exposed to high light stress for 24 hours for a week. Following the high light stress, rats were treated with low dose and high dose agomelatine (by gavage) for 14 days. Stress group was exposed to high light stress for 24 hours for 21 days. Only agomelatine was applied for 14 days in the AG treated group. In the control group any treatment were not used. At the end of the experiment, the brains of the rats were removed, histological sections were taken. After that the routine hematoxylin eosin and immunohistochemical (NF-κB and C-fos) stainings were performed.
RESULTS: According to histopathological findings, in the Control and AG groups normal brain cortex was observed. The shrinkage of neurons was detected in the LS group, but not in the LS + AG and the control groups. Immunohistochemical findings revealed that, NF-κB immunoreactivity was increased in neurons of the LS group, but in the LS + AG groups immunoreactivity was similar to the control group. C-fos immunostaining findings have also been shown, immunopositivity decreased in the LS group when compared to the control group, whereas C-fos immunoreactivity increased in the LS + AG groups.
CONCLUSION: In the light of the obtained findings, agomelatine was clearly thought to have a protective role in the oxidative stress damage caused by the high light stress.