Kahweol Found in Coffee Inhibits IL-2 Production Via Suppressing the Phosphorylations of ERK and c-Fos in Lymphocytic Jurkat Cells

Interleukin-2 (IL-2) is a cytokine involved in the development and maturation of the subsets of T cells, critically associated with the progression of several immune-related diseases (e.g. liver disease, bowel disease). Interestingly, a recent study suggests that coffee may contain several compounds to inhibit IL-2 expression in activated T-lymphocytic cells. However, there is little information about the potential effects of several coffee compounds (e.g. kahweol, cafestol, trigonelline, niacin and chlorogenic acids) on IL-2 expression in activated T-lymphocytic cells. Therefore, in this paper, their effects on IL-2 expression were evaluated in PHA/PMA-activated lymphocytic Jurkat cells. Among the tested compounds, only kahweol and cafestol were able to reduce IL-2 production significantly in the cells (p < 0.05). However, the inhibition of kahweol was a bit stronger than cafestol. Therefore, the molecular mechanism underlying the IL-2 inhibition was investigated using kahweol. Kahweol (≤ 20 µM) was able to inhibit the phosphorylations of ERK and c-Fos (p < 0.05) with little effects on p38 and JNK phosphorylations in the Jurkat cells. Subsequently, the inhibition of ERK/c-Fos led to the reduction of IL-2 mRNA expression in the Jurkat cells. In summary, the data suggest that kahweol may be a potential coffee compound to reduce IL-2 production via inhibiting the phosphorylations of ERK/c-Fos in PHA/PMA-activated lymphocytic Jurkat cells.