CoQ10vsPolygala Tenuifolia

CoQ10 (ubiquinone/ubiquinol) shuttles electrons between Complex I (NADH dehydrogenase) and Complex II (succinate dehydrogenase) and Complex III (cytochrome bc1 complex) of the mitochondrial electron transport chain. This is the fundamental process of oxidative phosphorylation—electrons flow through the chain to Complex IV, driving proton pumping and ATP synthesis via Complex V (ATP synthase). Without adequate CoQ10, the chain bottlenecks at the CoQ pool and energy production drops, particularly in high-metabolic tissues like neurons. As a lipid-soluble antioxidant, CoQ10 (in its reduced ubiquinol form) protects mitochondrial membranes from lipid peroxidation by terminating free radical chain reactions. It also regenerates vitamin E (tocopherol) from its radical form, amplifying antioxidant capacity. Brain CoQ10 levels decline with age.

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.