BACKGROUND/AIMS: Cyclophosphamide (CP) is a promising treatment for severe cases of paraquat (PQ) poisoning. We investigated the effective dose of CP for mitigating PQ-induced lung injury. METHODS: Adult male Sprague-Dawley rats were allocated into five groups: control, PQ (35 mg/kg, intraperitoneal injection), and PQ + CP (1.5, 15, or 30 mg/kg). The dimensions of lung lesions were determined using X-ray microtomography (micro-CT), and histological changes and cytokine levels were recorded. RESULTS: The micro-CT results showed that 15 mg/kg CP was more effective than 1.5 mg/kg CP for treating PQ-induced lung injury. At a dose of 1.5 mg/kg, CP alleviated the histological evidence of inflammation and altered superoxide dismutase activity. Using 15 mg/kg CP reduced the elevated catalase activity and serum transforming growth factor (TGF)-beta1 level. CONCLUSIONS: A CP dose of > 15 mg/kg is effective for reducing the severity of PQ-induced lung injury as determined by histological and micro-CT tissue examination, possibly by modulating antioxidant enzyme and TGF-beta1 levels.
Animals ; Catalase/metabolism ; Cyclophosphamide/*pharmacology ; Cytokines/metabolism ; Disease Models, Animal ; Dose-Response Relationship, Drug ; Immunosuppressive Agents/*pharmacology ; Inflammation Mediators/metabolism ; Lung/*drug effects/metabolism/pathology/radiography ; Lung Injury/chemically induced/diagnosis/*drug therapy/metabolism ; Male ; Oxidative Stress/drug effects ; *Paraquat ; Pulmonary Edema/chemically induced/diagnosis/*drug therapy/metabolism ; Rats ; Rats, Sprague-Dawley ; Severity of Illness Index ; Superoxide Dismutase/metabolism ; Transforming Growth Factor beta1/metabolism ; X-Ray Microtomography