Alpha‐linolenic acid ameliorates bronchial asthma features in ovalbumin‐sensitized rats

Objectives Effect of alpha‐linolenic acid (ALA) against ovalbumin (OVA)‐induced inflammation, oxidant/antioxidant imbalance and pathological features was examined in rat. Methods Total and differential WBC count and oxidant/antioxidant levels in BALF (bronchoalveolar lavage fluid) as well as lung pathological features were investigated in five groups of rats including controls (group C), rats sensitized with OVA (group S) and S treated with either ALA (0.2 and 0.4 mg/ml) or dexamethasone. Key findings As compared to group C, in OVA‐sensitized rats, increases in WBC counts, levels of oxidant biomarkers and most pathological scores were observed while lymphocyte percentage and antioxidants levels decreased. Treatment with ALA (0.2 and 0.4 mg/ml) significantly reduced total WBC, NO2 and NO3 levels, interstitial fibrosis and emphysema compared to sensitized group. The higher dose of ALA also significantly decreased neutrophil, eosinophil, and monocyte counts, MDA levels and interstitial inflammation but increased lymphocyte counts, as well as antioxidants levels, compared to sensitized group. Dexamethasone administration led to a significant improvement of most factors compared to group S but had no effects on total WBC count, bleeding and epithelial damage. Conclusions Alpha‐linolenic acid suppressed inflammation and oxidative stress, making it a potential therapeutic candidate for treatment of airway inflammatory diseases such as bronchial asthma.