Callicarpa japonica Thunb. ameliorates allergic airway inflammation by suppressing NF-κB activation and upregulating HO-1 expression

Abstract

Ethnopharmacological relevanceCallicarpa japonica Thunb., as an herbal medicine has been used for the treatment of inflammatory diseases in China and Korea. Materials and methodsUltra performance liquid chromatography–photodiode array–quadrupole time–of–flight mass spectrometer (UPLC–PDA–QTof MS) was used to detect the major phenylethanoid glycosides in the C. japonica extract. BALB/c mice were intraperitoneally sensitized by ovalbumin (OVA) (on days 0 and 7) and challenged by OVA aerosol (on days 11–13) to induce airway inflammatory response. The mice were also administered with C. japonica Thunb. (CJT) (20 and 40 mg/kg Per oral) on days 9–13. CJT pretreatment was conducted in lipopolysaccharide (LPS)-stimulated RAW264.7 or phorbol 12-myristate 13-acetate (PMA)-stimulated A549 cells. ResultsCJT administration significantly reduced the secretion of Th2 cytokines, TNF-α, IL-6, immunoglobulin E (IgE) and histamine, and the recruitment of eosinophils in an OVA-exposed mice. In histological analyses, the amelioration of inflammatory cell influx and mucus secretion were observed with CJT. The OVA-induced airway hyperresponsiveness (AHR), iNOS expression and NF-κB activation were effectively suppressed by CJT administration. In addition, CJT led to the upregulation of HO-1 expression. In an in vitro study, CJT pretreatment suppressed the LPS-induced TNF-α secretion in RAW264.7 cells and attenuated the PMA-induced IL-6, IL-8 and MCP-1 secretion in A549 cells. These effects were accompanied by downregulated NF-κB phosphorylation and by upregulated HO-1 expression. ConclusionThese results suggested that CJT has protective activity against OVA-induced airway inflammation via downregulation of NF-κB activation and upregulation of HO-1, suggesting that CJT has preventive potential for the development of allergic asthma.