The Protective Effects of Preventive Atomisation Inhalation of Edaravone on the Lung Tissues of Rats with Smoke Inhalation Injury

Abstract

Objective: To investigate the protective effects of the atomisation inhalation of edaravone on the lung tissues of rats with smoke inhalation injury. Methods: Forty male Sprague-Dawley (SD) rats were randomly divided into four groups of ten rats each: normal control group (group A), normal saline atomisation group (group B), edaravone aerosol group (group C) and edaravone atomisation prevention group (group D). Barring group A, the groups were used to create a model of severe smoke inhalation injury. However, before developing the model, group D rats were made to inhale edaravone (3.6 mg/mL) for 10 min. Six hours following smoke inhalation injury, abdominal artery blood samples were centrifuged, the lung tissue homogenate was prepared and carotid artery blood samples were used for blood gas analysis and oxygenation index (PaO 2 /FiO 2 ) calculation. The levels of tumour necrosis factor alpha (TNF- α ), interleukin (IL) 6 and IL-10 in serum and the levels of cysteine protease 3 (caspase-3), malondialdehyde (MDA), myeloperoxidase (MPO) and superoxide dismutase (SOD) in lung tissues were examined. The wet-dry ratio (W/D) and water content of the lung tissue were calculated, and the TUNEL method was used to determine the rate of lung tissue apoptosis in each group. Tissue specimens were obtained from the partial lung for histopathological examination. Results: Compared with those in group A, the water content of the lung tissue, the rate of lung tissue apoptosis, W/D and the caspase-3, TNF- α , IL-6, IL-10, MDA and MPO levels were significantly greater in other groups ( P < 0.05), whereas the levels of SOD and PaO 2 /FiO 2 were lower ( P < 0.05). Compared with those in group B, the levels of W/D, the water content of the lung tissue, the rate of lung tissue apoptosis and the levels of caspase-3, TNF- α , IL-6, MDA and MPO were significantly low ( P < 0.05) and the levels of IL-10, SOD and PaO 2 /FiO 2 were significantly high in groups C and D ( P < 0.05). The expression of the aforementioned factors was more evident in Group D ( P < 0.05). Histopathological examination revealed that groups C and D had greater levels of inflammatory granulocytes than group B. This was more evident in group D. Conclusions: The inhalation of edaravone can reduce smoke inhalation-induced lung injury. This may be related to the inhibition of apoptosis, the reduction of peroxidation injury and the production/release of inflammatory mediators/free radicals. It exerts a remarkable preventive effect.