Evaluation of the effect of kaempferol in a murine allergic rhinitis model.

Kaempferol (KP) is a major compound of Naju Jjok (Polygonum tinctorium Lour.). The effect of KP on allergic rhinitis (AR) has not been elucidated. Here, we report the effects and mechanisms of KP on new and predominant mediators of AR using an eosinophil cell line, Eol-1 and an ovalbumin (OVA)-induced AR mouse model. KP significantly inhibited the production of interleukin (IL)-32 and IL-8 and activation of caspase-1 in Eol-1 cells. Allergic symptoms and predominant mediators (IgE and histamine) in the KP-administered group were significantly lower than in the AR group. The levels of interferon-γ were enhanced while the levels of IL-4 were reduced in the KP group. KP significantly reduced the levels of IL-32 and thymic stromal lymphopoietin (TSLP) compared with the AR mice. KP reduced the levels of inflammation-related proteins. In the KP-administered groups, the infiltrations of eosinophils and mast cells increased by OVA were decreased. In addition, KP significantly reduced caspase-1 activity in nasal mucosa tissue of AR mice. Our findings indicate that KP has an anti-allergic effect through the regulation of the production of IL-32 and TSLP and caspase-1 activity in allergic diseases including AR.