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

The effects and enhancement of catalpol (CP) on specific immune therapy (SIT) were investigated with an established animal model associated with bronchial asthma. 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. 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. 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.