Inhibitory effect of hydroalcoholic extract of Cunila spicata Benth. on phlogistic agents-induced cellular migration in the airways of mice.

Abstract

Cunila spicata Benth. Is a creeping and aromatic plant that has an ethnopharmacological indication in the southern region of Brazil, in the Araucaria Forest biome. It's used as an alternative therapy for respiratory diseases for men and animals since the "tropeirista" movement in colonial Brazil. Investigate the influence of oral administration of hydroalcoholic extract of C. spicata (HECS) on cellular inflammatory processes in the airways of mice. The HECS was obtained by the ultrasound-assisted technique. Phytochemical analysis of the volatile compounds was performed using gas-chromatography with mass spectrometry. To investigate the biological activity of HECS, the animals were pre-treated with HECS orally 1h before and the bronchoalveolar lavage (BAL) model was used, in which the animals were subjected to inhalation of different pro-inflammatory agents such as carrageenan (CAR), histamine (HIST), capsaicin (CAP), bradykinin (BK), and 48/80 compound (C48/80). After sacrifice, BAL sample was collected from the bronchi and was analyzed for total and differential white blood cell counts, compared with control groups. Fourteen volatile phytocompounds were identified in the HECS, the main ones being 2-bornanone, menthofuran and camphene. Among the HECS treated animals, all showed significant maximal inhibition (MI) when challenged with pro-inflammatory agents by nebulization. In the group of animals that received CAR, the MI was 72.77±3.88%, compared to the negative control (NC). There was a predominance of lymphocytes (59.18±4.07%). For the HIST group, MI was 64.03±4.33%, in relation to the NC, with predominance in macrophages number (76.53±2.78%). In the CAP group, the MI obtained was 38.90±11.31%, with greater macrophage migration occurring (80.98±3.44%) in the higher dose. For animals subjected to BK inhalation, the MI was 48.63±3.95% with macrophages predominance (64.33±10.04%). In the group that received C48/80 inhalation, the MI was 40.25±5.30% (100mgkg-1), with higher occurrence of macrophages (72.97±4.23%). Our results suggest that HECS had a non-specific inhibitory effect on cellular migration induced by different pro-inflammatory agents, reducing inflammation in airways of mice. These effects coincide and support its ethnopharmacological use as an alternative medicine for respiratory diseases in regions where the plant is prevalent.