Curcumin blocks interleukin (IL)-2 signaling in T-lymphocytes by inhibiting IL-2 synthesis, CD25 expression, and IL-2 receptor signaling

► Curcumin inhibits CD4+ T-lymphocyte proliferation. ► Curcumin inhibits interleukin-2 (IL-2) synthesis and CD25 expression by CD4+ T-lymphocytes. ► Curcumin interferes with IL-2 receptor signaling by inhibiting JAK3 and STAT5 phosphorylation. ► IL-2-dependent regulatory T-lymphocyte function and Foxp3 expression is downregulated by curcumin.