Time course study of oxidative stress in sulfur mustard analog 2-chloroethyl ethyl sulfide-induced toxicity

Oxidative stress is the major mechanism impairing cell homeostasis, inducing cell death and tissue damage in sulfur mustard (SM)-exposed individuals. The aim of the present study was to evaluate time course changes of oxidative stress in the mice exposed with 2-chloroethyl ethyl sulfide (CEES) as SM analog. For this purpose, male BALB/c mice were divided into control groups and experimental groups that received CEES (10 mg/kg) through intraperitoneal injection. In both groups, animals were euthanized at three periods: short (12, 24 h and 1 week), medium (1, 2 and 3 months) and long-term (5 and 6 months) after CEES exposure. Oxidative stress indices and the antioxidant defense systems were evaluated in lung and liver tissues. The time course findings in both tissues showed a significant increase in oxidative damage markers such as malondialdehyde (lung P < 0.001, liver P < 0.001), protein carbonyl (lung P < 0.0001), and 8-hydroxy-deoxyguanosine (lung P < 0.0001, Liver P < 0.0001) and also a significant reduction in the antioxidant defense system including reduced glutathione level (lung P < 0.001, Liver P < 0.001,), activities of catalase (lung P < 0.01 and liver P < 0.05), superoxide dismutase (lung P < 0.05), glutathione S-transferase (lung P < 0.05, liver P < 0.01), glutathione peroxidase (lung, P < 0.05, Liver P < 0.05) and glutathione reductase (lung P < 0.001, liver P < 0.01) in the long-term. However, these changes occur with less intensity in the short-term and return to the normal status in the medium-term. Moreover, there was a positive time course correlation between oxidative damage indices and the percent of histopathological damage in both tissues (P < 0.05). This correlation finding confirms and supports the fact that time course oxidative-antioxidant imbalance plays an important role in the development of SM-induced acute and delayed injuries.