Background

Chronic diseases - spanning cardiovascular–metabolic, infectious, hepatic–gastrointestinal, neurodegenerative, and epithelial domains - share a unifying molecular foundation: oxidative stress, inflammatory amplification, and regenerative failure.

Onion extract (Allium cepa L.), a clinically characterized source of quercetin and organosulfur compounds, exhibits multi-axis regulatory potential across these systems.

Within the Keyora Nutritional Pharmacology Tri-Axis Framework, its actions are organized along three converging biological axes - Redox Stabilization, Inflammatory Resolution, and Regenerative Reconstruction - establishing a mechanistic model that bridges nutrition and molecular medicine.

Methods

A translational synthesis of human clinical trials, mechanistic studies, and biochemical analyses was conducted to evaluate onion extract at clinically validated intakes (20-40 mg/day).

Disease-specific evidence was systematically reviewed across five domains:

(1) Cardiovascular–metabolic disorders (atherosclerosis, metabolic syndrome, type II diabetes mellitus, and nonalcoholic fatty liver disease)

(2) Infectious and post-infectious conditions (influenza, upper respiratory infections, viral pharyngitis, and post-/Long COVID),

(3) Hepatic and gastrointestinal diseases (chronic hepatitis, NAFLD, inflammatory bowel disease, and Helicobacter pylori infection),

(4) Neurodegenerative and neuroinflammatory disorders (Alzheimer, Parkinson disease, and stress-related cognitive impairment)

(5) Cutaneous-oral barrier diseases (gingivitis, oral ulceration, eczema, dermatitis, and chronic wounds).

The synergistic effects of onion extract combined with propolis as established in the Keyora Dual-Phase Regenerative Model - were further examined for molecular complementarity and clinical reinforcement.

Results

Across multiple human studies, onion extract consistently improved biochemical and clinical endpoints related to oxidative stress, inflammation, and tissue repair.

In cardiovascular–metabolic disease, it activated Nrf2–SIRT1–PGC-1α signaling, reduced serum MDA (−25–35 %), normalized lipid profiles, and improved insulin sensitivity.

In infectious and post-infectious conditions including post-/Long COVID, onion extract decreased circulating IL-6, TNF-α, and CRP levels, while enhancing mucosal integrity and reducing fatigue scores.

Hepatic and gastrointestinal studies demonstrated suppression of COX-2/iNOS, restoration of mitochondrial respiration, reduction of hepatic steatosis, and inhibition of H. pylori adhesion.

Neurocognitive trials revealed enhanced antioxidant capacity, elevated BDNF levels, improved MMSE scores (+15–18 %), and reduced neuroinflammatory markers.

Dermatological and oral studies confirmed accelerated epithelial closure (+30-40 %), decreased scar hypertrophy, and significant reductions in gingival inflammation and lesion recurrence.

Integration with propolis extended these effects temporally and mechanistically:

• Phase I - rapid oxidative and inflammatory recovery via Nrf2 activation and NF-κB/NLRP3 suppression;
• Phase II - sustained structural regeneration through TGF-β/VEGF–Smad3–mediated collagen and angiogenic repair.

Together, these dual phases produced a regenerative continuum spanning molecular stabilization to tissue renewal, achieving measurable cross-system benefits in oxidative balance, inflammation control, and functional recovery.

Conclusion

Within the Keyora Redox–Inflammatory–Regenerative Tri-Axis, onion extract functions as a systemic synchronizer of oxidative control, immune modulation, and structural regeneration.

By translating redox normalization into long-term tissue resilience - especially when combined with propolis - it transcends traditional antioxidant paradigms to define a new class of regenerative nutritional pharmacology.

This integrative approach demonstrates translational efficacy across cardiovascular, metabolic, infectious, hepatic, neurodegenerative, and barrier pathologies, providing a mechanistic foundation for precision nutrition in chronic disease prevention and recovery.