CaffeinevsPanax Ginseng

Caffeine is a non-selective adenosine receptor antagonist with highest affinity for A1 and A2A subtypes. Adenosine accumulates during wakefulness and promotes sleepiness by binding to A1 receptors (inhibiting adenylyl cyclase and reducing neuronal excitability) and A2A receptors (modulating dopamine D2 receptor signaling in striatum). Caffeine competitively blocks these receptors, preventing the drowsiness signal. This disinhibition indirectly increases dopamine, norepinephrine, and acetylcholine neurotransmission via downstream pathways. Caffeine also inhibits phosphodiesterase (PDE) enzymes—particularly PDE4 in the brain—reducing cAMP degradation. Elevated intracellular cAMP amplifies catecholamine signaling through PKA-mediated phosphorylation of CREB and other transcription factors, enhancing alertness and cognitive performance.

Ginsenosides (Rb1, Rg1, Rg3, Re, and others) have diverse pharmacological actions. They modulate the hypothalamic-pituitary-adrenal (HPA) axis, reducing cortisol release under stress through glucocorticoid receptor modulation. Ginsenosides inhibit acetylcholinesterase (AChE), increasing acetylcholine levels in the hippocampus and enhancing muscarinic and nicotinic receptor function. They enhance nitric oxide production via endothelial nitric oxide synthase (eNOS) for cerebral vasodilation. Rb1 and Rg1 promote BDNF and NGF expression through activation of CREB and TrkB/TrkA signaling, supporting neuroplasticity. Rg1 specifically enhances hippocampal neurogenesis via the PI3K/Akt pathway and Wnt/β-catenin signaling, and improves spatial learning in animal models. Ginsenosides may also modulate GABA-A receptors and have antioxidant properties.