Antidepressant Like Effect of Endogenous SO 2 on Depression Caused by Chronic Unpredictable Mild Stress

Abstract

Abstract Sulfur Dioxide (SO2) is a toxic gas with harmful effects on various organs but recent studies, have confirmed the protective effect of SO2 on ischemic heart disease, atherosclerosis, and lung infections. The present study was designed to investigate the effect of endogenous SO2 on depression. Chronic Unpredictable Mild Stress (CUMS) model was performed to cause depression. Depression-Like Behaviors in animals were determined using open-field test, forced swimming test and sucrose consumption. Animal spatial learning and memory was assessed using the Morris water maze. The oxidative status of the hippocampus and serum corticosterone level assessed. A reduction in the tendency to consume sucrose, mobility, and curiosity, as well as learning and memory disorders were observed in CUMS animals. Depressed animals treated with SO2 showed a significant improvement in behavioral and cognitive functions. SO2 also reduced neuronal damage and lipid peroxidation of the hippocampus and serum corticosterone level in the CUMS group. Various evidences supports a mutual relationship between inflammation and depression, also growing studies shows the role of oxidative stress in the pathogenesis of mood-related disorders such as depression. In this study, increased hippocampal malondialdehyde (MDA) and serum corticosterone levels can be reasons for the existence of oxidative stress and possible activation of inflammatory processes. SO2 donors reduced MDA and corticosterone levels in depressed animals. According to these results, SO2 may have been able to reduce tissue damage and eventually behavioral disorders caused by depression by reducing oxidative stress and inflammation.