Caffeine and its main targets of colorectal cancer

Figure 4 The main acting sites and physiological processes modulated by caffeine on colorectal cancer involved in this article. Through modulating acting sites such as phosphodiesterase, adenosine, Ca²⁺, catecholamines and γ-aminobutyric acid receptor, caffeine can exert varied effects (promote or inhibit) on physiological processes such as signal pathways, immune response, gut bacteria, cell cycle and oxidative stress. PDE: Phosphodiesterase; AR: Adenosine receptor; CA: Catecholamines; GABAAR: γ-aminobutyric acid receptor.