The effect of matured date palm tree (Phoenix dactylifera L.) fruit extract on mite-induced allergic symptoms in NC/Nga mice

The effect of a hot water extract of matured date palm tree fruit on allergic responses was investigated in NC/Nga mice. The allergic score was significantly reduced in the mice fed a date palm tree fruit extract-added diet than the fruit extract-free diet. The levels of serum antigen-specific immunoglobulin E and spleen interleukin (IL)-4⁺CD4⁺ cells were significantly lowered in the mice fed the fruit extract-added diet. Bruton's tyrosine kinase (Btk) and IL-2-inducible T cell kinase (Itk) mRNA expressions in spleen cells were significantly lowered in the mice fed the fruit extract-added diet. Moreover, chlorogenic acid and pelargonin decreased these mRNA expressions in C3H/HeN mouse spleen cell cultures. These results suggest that the date palm tree fruit extract may reduce allergic symptoms in mice via a decrease in the number of type 2 helper T (Th2) cells, and a suppression of the expression of kinases involved in mast cell degranulation and Th2 cell differentiation.