Objective: Croton zehntneri Pax et Hoffm. is a Euphorbiaceae species, popularly known as "canela de cunhã," a native plant of northeastern Brazil, whose essential oil (EOCZ) shows relatively specific myorelaxant action for the smooth muscle of the airways and in the respiratory tract. Based on this information, EOCZ figures as a candidate for testing in the treatment of asthma, and the present study investigated the benefits of using EOCZ in an ovalbumin-induced asthma model.
Methods: 48 male BALB/c mice were divided into six groups (n = 8). In the ST, SO100, and SO300 groups, mice were sensitized and challenged with saline, and then treated with 200 µL of 0.1% Tween 80, 100 mg/kg EOCZ and 300 mg/kg EOCZ, respectively. In the OT, OO100, and OO300 groups, mice were sensitized and challenged with OVA, and then treated with 200 µL of 0.1% Tween 80, 100 mg/kg EOCZ and 300 mg/kg EOCZ, respectively.
Results: Our results demonstrated significant changes in all respiratory mechanics variables analyzed between the OO300 and OT groups demonstrating the effectiveness of EOCZ to attenuate the OVA-induced lung injury. In addition, the use of EOCZ at a dose of 300 mg/kg showed an antioxidant effect and decreased inflammatory cells in the pulmonary parenchyma. In conclusion, our results demonstrated that EOCZ was able to improve the lesion in the respiratory system of mice subjected to OVA-induced asthma.
Conclusions: The antioxidant action of EOCZ was likely the main mechanism of action in the reversal of this lesion, so more tests should be performed for its confirmation.
Keywords: Euphorbiaceae; OVA-induced asthma; essential oil; respiratory system.