Abstract
COPD is characterized by irreversible airflow obstruction, inflammation, oxidative stress imbalance and lung remodeling. Monoterpenes derived from essential oils have showed anti-inflammatory and anti-oxidant activity. The tymol and carvacrol displayed hydroxyl groups at C-3 and C-2 positions, respectively, while in the p-cimene, the hydroxyl group is not present.
Aims: To evaluate, in a model of elastase-induced emphysema, the effects of these natural compounds and whether the differences in the chemical structure could affect the biological effects.
Methods: Mice received intranasal saline or elastase and were treated with tymol, carvacrol, p-cimene or vehicle 30 min later and again on days 7, 14 and 28. We evaluated lung function and the inflammatory profile in bronchoalveolar lavage fluid (BALF). The lungs were removed and submitted to histological evaluation.
Results: In the elastase-instilled animals, carvacrol, tymol or p-cimene reduced the alveolar enlargement, macrophage and the levels of IL-1b, IL-6, IL-8 and IL-17 in the BALF, the collagen fibers, the number of MMP-9 and p-65-NF-kB-positive cells in lung parenchyma (P<0.05). All the treatments attenuated the levels of 8-iso-PGF2a of elastase-treated animals but only tymol was able to reduced exhaled nitric oxide (P<0.05). Only in the carvacrol-treated animals the number of TIMP-1-positive cells increased (P<0.05).
Conclusion: The tymol, carvacrol and p-cimene reduced lung alterations in elastase-induced emphysema in mice which suggest that the presence or the position of hydroxyl group does not interfere with the biological effects of these compounds in this model. Supported by FAPESP and CNPq.
- Copyright ©the authors 2016
