Lonicerin alleviates ovalbumin-induced asthma of mice via inhibiting enhancer of zeste homolog 2/nuclear factor-kappa B signaling pathway.

Asthma is the most common chronic disease in the respiratory system of children caused by abnormal immunity that responses to common antigens. Lonicerin exerts anti-inflammatory activity in other inflammatory models through targeting enhancer of zeste homolog 2 (EZH2) that is related to asthma. We sought to explore the role and mechanism of lonicerin in regulating allergic airway inflammation. Mice were intraperitoneally injected 10 µg ovalbumin (OVA) on postnatal day 5 (P5) and P10, and then inhaled 3% aerosolized OVA for 10 min every day on P18-20, to establish asthmatic mice model. Lonicerin (10 or 30 mg/kg) was given to mice by intragastric administration on P16-P20. Notably, the administration of lonicerin amended infiltration of inflammatory cells and mucus hypersecretion. OVA-specific IgE level, inflammatory cell count and inflammatory cytokines in asthmatic mice were reduced after lonicerin treatment. Moreover, it suppressed the activity of EZH2 and activation of nuclear factor-kappa B (NF-κB) as evidenced by decreasing tri-methylation of histone H3 at lysine 27 and reducing nuclear translocation of NF-κB p65. In a word, Lonicerin may attenuate asthma by inhibiting EZH2/NF-κB signaling pathway.