Global Scientific Consensus Validates Quercetin’s Multi-System Health Benefits: FDA & International Regulatory Approvals Pave Way for Clinical Applications

2025-08-11

Mounting evidence positions quercetin—a potent plant-derived flavonoid—as a cornerstone in combating age-related diseases through targeted modulation of oxidative stress, inflammation, and metabolic dysfunction. Regulatory approvals (FDA, Japan, Korea) confirm safety as a Dietary Supplement.

I. Natural Sources & Biochemical Profile

Primary Sources (Avg. daily intake: 25–50 mg):
Onions (>100 mg/100g), apples, green tea, cherries, red grapes, cilantro.
Bioactivity:
5 hydroxyl groups enable free radical neutralization (H₂O₂, O₂⁻), outperforming standard antioxidants.

II. Mechanisms of Action: Molecular Pathways

① Antioxidant Defense System

Activates Nrf2/ARE pathway → ↑SOD/GPx expression
Inhibits NADPH oxidase (NOX) assembly → ↓ROS generation by 68% (Cell Senescence, 2023)

② Anti-Inflammatory Mastery

Suppresses NF-κB signaling → ↓TNF-α/IL-6 (70% reduction in murine psoriasis models)
Blocks STAT3 phosphorylation → Halts IL-23/IL-17A axis

III. Therapeutic Applications Across Diseases

Condition	Observed Effect	Mechanism
Neurodegeneration	↓β-amyloid plaques; cognitive recovery	Blood-brain barrier penetration
Diabetes	Fasting glucose ↓15%; ↑GLUT4 expression	AMPK activation (+ metformin synergy)
Cancer (Breast/Colon)	Tumor shrinkage; apoptosis induction	G2 cell-cycle arrest; angiogenesis inhibition
Cardiovascular	Atherosclerotic plaques ↓40%	ACAT/PPARα modulation; ↑fatty acid oxidation

IV. Bioavailability Solutions & Safety

Absorption Challenge: 5–10% baseline → 81% via:
- Glycoside hydrolysis
- Vitamin C/fat co-administration
Dosing: ≤1,000 mg/day (Higher doses risk pro-oxidant effects)
Drug Interactions: Contraindicated with antibiotics/anticoagulants

V. Future Directions: Precision Delivery

Nano-Encapsulation (PLGA/liposomes) boosts tumor targeting
FDA-Approved Synergies: Quercetin-phosphatidylcholine complexes (US5043323)