Suppression of thymic stromal lymphopoietin production by rutin in mast cells

Thymic stromal lymphopoietin (TSLP) is a key player in allergic diseases such as asthma and atopic dermatitis. Rutin (RU), a non-nutritive component of many foods, possesses anti-inflammatory, hepatoprotective, and anti-tumour effects. We investigated how RU inhibits the production of TSLP in human mast cell line (HMC-1) cells. RU inhibited the production and mRNA expression of TSLP in HMC-1 cells. The maximal inhibition rate of TSLP production by RU (50 μM) was 56.25 ± 2.81%. Nuclear factor-κB luciferase activity induced by phorbol myristate acetate plus A23187 was inhibited by RU. In the activated HMC-1 cells, the activation of caspase-1 was increased, whereas the activation of caspase-1 was decreased by pre-treatment with RU. Finally, RU inhibited the numbers of TSLP-positive mast cells in lesions of PMA-induced ear oedema model. These results suggest that RU would be helpful for the treatment of inflammatory and atopic diseases through the inhibition of TSLP.