As B. napus oil contains high levels of antioxidants such as omega-3 and vitamin E, it can reduce necrosis and migration of eosinophils as well as inhibits smooth muscle cell hyperplasia in the walls of respiratory tract by decreasing the amount of leukotrienes, IL-13, and IL-4. B. napus oil improves some symptoms of experimental asthma in rats. This evidence concerns the gene IL4 and asthma.