Panax GinsengvsPolygala Tenuifolia

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.

The saponins (tenuigenin, polygalasaponins, onjisaponins) and oligosaccharide esters (3,6'-disinapoyl sucrose, tenuifolisides) have multiple neurological actions. They inhibit acetylcholinesterase (AChE) at the catalytic site, increasing synaptic acetylcholine and enhancing muscarinic M1/M4 and nicotinic receptor signaling. They promote BDNF and NGF expression via CREB and ERK/MAPK pathways, supporting neuroplasticity and neurogenesis in the hippocampus and subventricular zone. They modulate NMDA receptor function (possibly as positive allosteric modulators at the glycine site) and enhance long-term potentiation (LTP) via CaMKII and PKC. The anti-depressant effects involve monoaminergic modulation — increasing dopamine and norepinephrine via MAO inhibition or reuptake modulation — and HPA axis regulation (reducing CRH and cortisol). Tenuigenin may also activate TrkB receptors directly.