Buckwheat extracts (Fagopyrum tataricum) and rutin attenuate Th2 cytokines production and cellular allergic effects in vitro and in vivo

The key feature of food allergy is a T helper-2 cell (Th2)-predominant allergen-specific immune response. Rutin can increase PPAR-γ expression to improve diabetes; however, this effect whether attenuating Th2 signal is still unknown. The 75% ethanol extracts of buckwheat (EEB) and rutin (major active compound) significantly suppress interleukin-4 (IL-4) secretion from splenocytes in ovalbumin (OVA)-induced sensitive Balb/c mice; therefore, the inhibitory effects of EEB and rutin on Th2 signaling pathway in PMA/ionomycin-induced EL4 T cells were subsequently investigated. At the transcriptional level, rutin reduced the expression of Th2 markers such as GATA3 and p-STAT6 in PMA/ionomycin-induced EL4 T cells. Moreover, we used the PPAR-γ antagonist GW9662 to confirm that rutin skewed the immunological function toward Th2 activity through regulation of PPARγ expression. Taken together, EEB and rutin may have the potential to regulate immune responses, thereby deeming them useful in reducing food hypersensitivities and improving anti-cellular allergic responses.