Effects of Eucalyptol in respiratory system mechanics on acute lung injury after exposure to short-term cigarette smoke.

Eucalyptol is a compound that has demonstrated antioxidant, anti-inflammatory and bronchodilator effects, but there are no investigations about the effects of this constituent on the respiratory system mechanics in relation to acute lung injury caused by short-term cigarette smoke (CS) exposure. In view of the above, this work investigated the effects of Eucalyptol on the mechanics of the respiratory system of mice in short-term CS exposure. For this, we used data from respiratory mechanics in vivo, and histopathology and lung parenchymal morphometry analysis in vitro. The experiments were performed on C57black/6 mice divided into 5 groups. One group exposed to ambient air (AA + T), and another to cigarette smoke (CS + T) for 5 consecutive days and treated with 1% Tween 80 solution. The other groups were exposed to cigarette smoke for 5 consecutive days, and treated with Eucalyptol at doses of 30 mg/kg (CS + E30), 100 mg/kg (CS + E100), 300 mg/kg (CS + E300). Our results demonstrated significant changes in all variables of respiratory mechanics and lung parenchyma morphometry analyzed for the AA + T group compared to the CS + T group, confirming the establishment of the lesion induced by exposure to cigarette smoke. We also observed that mice treated with Eucalyptol orally at a dose of 300 mg/kg (CS + E300) showed improvement in all variables compared to the group exposed to cigarette smoke and treated with 1% Tween 80 (CS + T) demonstrating the effectiveness of Eucalyptol in preventing lung injury induced by exposure to CS. In conclusion, our results demonstrated that the Eucalyptol was able to prevent the acute lung injury in mice submitted to short-term cigarette smoke exposure.