Anti-inflammatory and anti-oxidative effects of Myrtenol in the rats with allergic asthma

Abstract Aims: To investigate the effect of Myrtenol, the active ingredient of Myrtle, on the oxidant and anti-oxidant indices and cytokines in the allergic asthma. Methods: Allergic asthma was induced by ovalbumin (OVA) sensitization and inhalation in four groups of rats; Control, Asthma, Asthma+Dexamethasone and Asthma+Myrtenol. Myrtenol (50mg/kg) or Dexamethasone (2.5mg/kg) was administered intraperitoneally for 7 consecutive days after OVA inhalation. At the end, histopathological parameters and interleukins (Interleukin-10 (IL10), Interferon gamma (IFN-γ) , interleukin-1β (IL-1β), Tumor Necrosis Factor α (TNF-α)) and oxidative stress biomarkers, Malondialdehyde (MDA), superoxide dismutase (SOD) and glutathione peroxidase (GPX) in the lung and serum were measured by hematoxylin & eosin staining and ELISA method respectively. Results: Myrtenol reduced the pathological changes in the lungs and airway endothelium (P<0.01), (P<0.5). The level of IL-1β (P < 0.05) and MDA in the serum and lung tissue (P < 0.01), (P < 0.05), and also the level of TNF-α (P < 0.05) in the lung tissue decreased in the Myrtenol group compared to the asthma group. Myrtenol increased the level of IL-10 ( P < 0.05) and the activity of GPX in the lung tissue and serum (P < 0.001). Conclusion: Myrtenol may improve asthma by increasing the ratio of antioxidants to oxidants and reducing the ratio of pro-inflammatory to anti-inflammatory interleukins in the lung. Myrtenol is presented as a potent herbal medicine ingredient for the treatment of asthma.