| Rank |
Pathway / Axis |
AD Modulation |
TSF |
Primary Effect |
Notes / Interpretation |
| 1 |
Acetylcholinesterase and cholinergic signaling |
AChE ↓ ACh ↑ |
P, R |
Increases synaptic acetylcholine and cholinergic neurotransmission. |
Best-established molecular mechanism and the mechanism most directly relevant to clinical dosing. |
| 2 |
Glutamate excitotoxicity and NMDA signaling |
Excitotoxicity ↓ NMDA overactivation ↓ |
P, R |
Reduces glutamate-associated neuronal injury. |
Important secondary pharmacology, but human clinical contribution relative to AChE inhibition is uncertain. |
| 3 |
BDNF TrkB PI3K Akt mTOR survival signaling |
BDNF ↑ TrkB ↑ p-Akt ↑ p-mTOR ↑ |
R, G |
Promotes neuronal survival and resistance to oxidative glutamate toxicity. |
Demonstrated mechanistically in neuronal cell models; substantially less clinically established than AChE inhibition. |
| 4 |
Oxidative stress and ROS |
ROS ↓ oxidative injury ↓ |
R, G |
Reduces oxidative neuronal injury and supports antioxidant defenses. |
Secondary neuroprotective mechanism; much of the evidence is preclinical and concentration-dependent. |
| 5 |
Mitochondrial integrity and apoptosis |
Mitochondrial dysfunction ↓ Bcl-2 ↑ Caspase-3 ↓ |
R, G |
Preserves mitochondrial function and reduces neuronal apoptosis. |
Closely linked to oxidative-stress and neurotrophic signaling rather than a clearly independent clinical mechanism. |
| 6 |
Amyloidogenic processing |
Aβ toxicity ↓ BACE1 ↓ (model-dependent) |
G |
May reduce amyloidogenic APP processing and Aβ-associated neuronal toxicity. |
Preclinical disease-modifying hypothesis; there is no established evidence that HupA reduces amyloid burden or alters AD progression in humans. |
| 7 |
Synaptic plasticity and neurotrophic support |
BDNF ↑ NGF ↑ (model-dependent) PSD95 ↑ (model-dependent) |
G |
Supports synaptic function and memory-related signaling. |
Likely overlaps with cholinergic stimulation and BDNF/TrkB signaling. |
| 8 |
Neuroinflammatory signaling |
Inflammation ↓ TNF-α ↓ (model-dependent) IL-1β ↓ (model-dependent) |
G |
Attenuates inflammatory signaling in experimental neurologic models. |
Secondary preclinical mechanism; not established as a clinically important anti-inflammatory treatment. |
| 9 |
Tau pathology |
p-Tau ↓ (model-dependent) |
G |
May indirectly reduce abnormal tau phosphorylation under selected experimental conditions. |
Evidence is substantially weaker than for cholinergic signaling and does not support classification as a direct anti-tau therapy. |
| 10 |
Clinical Translation Constraint |
Clinical certainty ↓ |
G |
Limits translation of mechanistically broad preclinical findings. |
Human trials are heterogeneous and many positive studies are small or methodologically limited. Purified HupA should not be equated with non-standardized H. serrata supplements. Cholinergic adverse effects and interactions with other cholinergic or anticholinergic drugs are relevant. |