Aims: Asthma is an airway complex disease defined by reversible airway narrowing and obstruction, airway hyper-responsiveness, airway chronic inflammation, and airway tissue remodeling. The aim of this study was to investigate the effect of canola oil on the total count and various types of leukocytes (white blood cells) in rats with experimental asthma.

Methods: In this experimental research, 36 Wistar rats were divided into 4 groups: negative control, positive control, asthmatic treated by 0.5ml/kg canola oil per day and asthmatic treated by 0.7ml/kg canola oil per day. At the end of the experiment, animals were bled from the heart and the total number and percentage of white blood cells were measured and evaluated. Statistical analysis was done using SPSS 16 software and the comparison of the groups was made by ANOVA statistical test.

Results: the total count of white blood cells decreased in the experimental group 2 compared to the positive control group (p<0.05). Percentage of lymphocytes increased in experimental group 2 compared to the positive control group (p<0.01). Neutrophils percentage decreased in experimental group 2 compared to the positive control group (p<0.001). Eosinophils percentage decreased in the groups treated by canola oil compared to the positive control group (p<0.001).

Conclusion: Canola oil decreases some of asthma complications including the changes in the total counts and percentage of various types of white blood cells in rats with experimental asthma.