Both eugenol and biseugenol treatments reduced lung alterations in an experimental model of elastase-induced pulmonary emphysema

•COPD is a high mortality and morbidity disease.•Eugenol and biseugenol attenuated elastase-induced emphysema in mice.•No additional effects were detected between these compounds.•These data can open new therapeutic possibilities. Chronic Obstructive Pulmonary Disease is a high prevalence disease, characterized by a diffuse chronic lung inflammation and alveolar destruction. The purpose of this study is to evaluate the therapeutic effects of eugenol and its dimmer biseugenol, both isolated from Brazilian plant Nectandra leucantha (Lauraceae) on pulmonary alterations in a model of experimental emphysema that was induced by porcine pancreatic elastase (PPE). First, we evaluated the anti-oxidative potential of both substances in silico. Posteriorly, C57BL/6 mice received 50 µl of PPE solution (intranasal instillation) for emphysema induction. Eugenol and biseugenol (20 mg/kg, i.p) was given for 8 days consecutively beginning 21 days after PPE instillation. Animals were euthanized on day 28, and lungs removed for histological analysis. Biseugenol showed higher antioxidant potential. In vivo, both compounds reduced alveolar destruction measured by mean alveolar diameter (Lm) and the inflammatory cells in bone marrow, in bronchoalveolar lavage fluid (BALF) and in lung tissue that was induced by PPE. These treatments also reduced positive cells to IL-1β, IL-6, IL-17, NF-kB, MMP-9, and iNOS in lung tissue. Only eugenol reduced the expression of TIMP-1 and Nrf2 in lung tissue. No effects of both compounds were observed in collagen deposition and in SOD-1 and 2 positive expressions in lung tissue. These data indicate that eugenol and biseugenol were effective in controlling emphysema and lung inflammation. These effects can be due to controlling MMP-9 and TIMP-1 and by reduction of iNOS. Both compounds may be effective tools, combined or not with conventional medication, to be considered in emphysema treatment. [Display omitted]