Abstract: Objective　To observe the effect of rhynchophylline solid lipid nanoparticles (Rhy-SLN) on the microRNA-155/p38 mitogen activated protein kinase (p38 MAPK) axis in asthmatic mice. Methods　Fifteen BALB/c mice were randomly divided into the normal control group, the model group and the Rhy-SLN group. The mice in Rhy-SLN group were given the Rhy-SLN (50 mg/kg) before each sensitization operation of aluminum hydroxide. The normal control group and the model group were given equal amount of normal saline. After intervention, the number of eosinophils was observed by the smear of alveoli lavage. HE staining was used to observe the pathological changes of lung tissue in mice. The activities of immunoglobulin E (IgE) and interleukin-13 (IL-13) in mice were determined by ELISA. The hydroxyproline level in the lung tissue of mice was detected by hydroxyproline test. Western blot assay was used to detect expression levels of α-SMA, collagenⅠ, p38 MAPK and p-p38 MAPK in lung tissue of mice. The expression of miR-155 in mouse lung tissue was detected by RT-PCR. Results　The number of eosinophils in BALF, the serum level of IgE and IL-13 in BALF of asthmatic mice were decreased in the Rhy-SLN group compared with those of the model group (P＜0.05). Rhy-SLN can reduce the infiltration of inflammatory cells in lung tissue, reduce expression levels of α-SMA, collagen Ⅰ, hydroxyproline and p-p38 MAPK in lung tissue of asthmatic mice (P＜0.05). The expression of miR-155 in lung tissue of mice was up regulated by Rhy-SLN (P＜0.05). Conclusion　Rhy-SLN can relieve asthma in mice, and its mechanism may be related to the regulation of the miR-155/p38 MAPK axis and reduction of airway inflammation.

Key words: asthma, disease models, animal, Phynchophylline, microRNAs, p38 mitogen-activated protein kinases, solid lipid nanoparticles, microRNA-155