Enhanced effect of catalpol on specific immune therapy in treatment of asthmatic mice

Objective: The effects and enhancement of catalpol (CP) on specific immune therapy (SIT) were investigated with an established animal model associated with bronchial asthma. Materials and methods: A total of 50 adults BALB/c mice were randomly divided into five groups with 10 mice in each group. These groups are control group, model group, CP group, SIT group and CP/SIT joint group. The mice were sensitized and challenged with OVA and Bronchoalveolar lavage fluid (BALF) and peripheral blood were obtained, the cell counts and the levels of cytokines (IL-1, IL-4, IFN-γ) in BALF were detected using ELISA methods. Results: The total number of cells in BALF of the group treated with CP/SIT joint group was significantly lower than the other experimental groups. Furthermore the eosinophils of the mice were dramatically reduced comparing the other experimental groups, the cytokines IL-1 and IL-4 display the similar tendency, but the IFN-γ concentration for the experimental groups was higher than the model group. After the therapy using CP, SIT and a combination of CP and SIT, asthma-associated inflammation was inhibited, IL-4 level was decreased and IFN-γ level was increased. In addition, the expression of TLR-4 protein in peripheral blood was detected by Western Blot method. Conclusions: In summary, CP can enhance the treating effect of SIT and the joint treatment by CP/SIT might be a potential method for clinical treatment of asthma, the mechanism is related to the inhibition of TLR-4 signaling pathway.