Objective(s): Allergic Asthma is an inflammatory disease of the lungs that is characterized by increased infiltration of leukocytes into the airways, limiting the respiratory function. Studies suggest that a defective general regulatory system against inflammation could be a significant factor in allergic asthma. It has been shown that Mesenchymal stem cells (MSCs) have a cellular immunosuppressive therapeutic potential for inflammatory disorders. We investigated whether administration of MSCs during allergen challenge would affect the underlying mechanisms in allergic airways inflammation. Materials and Methods: Fifty mice were used in five control and experimental groups; the experimental mice sensitized by intraperitoneal injection of OVA and aluminum hydroxide emulsion on days 0, 7, and 14, were then challenged intranasally with OVA or sterile PBS on days 14, 25, 26, and 27. Before allergen challenge on day 14, experimental mice received tail vein injection of MSCs in PBS, whereas control mice received PBS alone. Cytokine and IgE analyses were carried out using lung washes as well as serum samples.Results: Our, results showed that MSCs significantly reduced total cells and eosinophilia and serum OVA-specific IgE concentration in OVA-sensitized and challenged mice. Also, results showed that MSCs markedly inhibited expressions of Th2 and Th17 cytokines and elevated levels of Treg cytokines. Conclusion: we found that administration of MSCs could be used as a potential therapeutic approach for allergic asthma
