Ginkgo BilobavsPanax Ginseng

Ginkgo biloba extract (EGb 761) contains flavonoids (quercetin, kaempferol, isorhamnetin) and terpenoids (ginkgolides A, B, C, J and bilobalide). The flavonoids are potent antioxidants that scavenge superoxide, hydroxyl radicals, and peroxynitrite, and protect neurons from oxidative damage; they may also chelate iron. The terpenoids (ginkgolides and bilobalide) improve blood flow by antagonizing platelet-activating factor (PAF) at the PAF receptor, which reduces platelet aggregation, blood viscosity, and improves microcirculation in the brain. Bilobalide protects mitochondria and reduces apoptosis. Ginkgo modulates nitric oxide (NO) availability via endothelial nitric oxide synthase (eNOS) for vasodilation. It inhibits monoamine oxidase A and B (MAO-A, MAO-B), mildly elevating dopamine and serotonin. It may enhance cholinergic transmission and reduce amyloid aggregation.

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.