A major class of polyphenolic secondary plant metabolites (phytonutrients) with over 6,000 identified compounds, characterized by a C6-C3-C6 structure (two aromatic rings connected by a three-carbon chain). Flavonoids exhibit potent anti-inflammatory, antioxidant, and enzyme-modulating properties, particularly targeting gingipain enzymes in periodontal pathogens and supporting wound healing through multiple mechanisms.
Flavonoids work through multiple mechanisms: (1) Direct enzyme inhibition (particularly gingipains from P. gingivalis, reducing iron dysregulation cascade), (2) Aryl hydrocarbon receptor activation (supporting barrier function and immune tolerance), (3) NRF2 pathway activation (upregulating antioxidant defenses), (4) COX-2 and 5-LOX inhibition (reducing inflammatory eicosanoids), (5) Granulation tissue formation support (promoting angiogenesis and collagen synthesis). Specific flavonoids include quercetin, luteolin, catechins (EGCG from green tea), and anthocyanins. They require gut microbiome metabolism for bioactivailability—bacteria convert glycosides to aglycones that can be absorbed.
Flavonoids from cruciferous vegetables, green tea, berries, and herbs provide therapeutic effects beyond simple antioxidant activity. They directly inhibit pathogenic bacterial enzymes (gingipains), support oral and gut barrier function, modulate immune responses, and promote wound healing. In periodontal disease, flavonoid-rich interventions target the root mechanism (iron dysregulation via gingipain inhibition) rather than just symptom management.
- Over 6,000 identified flavonoid compounds in plant foods
- Quercetin reduces gingipain activity to 10-15% for Rgp, 35-40% for Kgp
- Luteolin shows even stronger inhibition, reducing both gingipains to <10%
- Green tea catechins (EGCG, EC) powerfully inhibit P. gingivalis enzymes
- Include quercetin, luteolin, catechins, anthocyanins, hesperidin, rutin
- Require gut microbiome for conversion from glycosides to absorbable aglycones
- Support granulation tissue formation in wound healing
- Activate NRF2 and AhR pathways for cellular protection
- Found in cruciferous vegetables, berries, green tea, citrus, herbs
- secondary plant metabolites — flavonoids are a major category of phytochemicals
- polyphenols — broader class that includes flavonoids
- green tea — rich source of catechin flavonoids (EGCG, EC)
- quercetin — specific flavonoid with potent gingipain-inhibiting activity
- Porphyromonas gingivalis — pathogen whose gingipains are inhibited by flavonoids
- periodontitis — treated by flavonoid inhibition of bacterial enzymes
- iron dysregulation — prevented by flavonoid inhibition of gingipain-mediated iron release
- granulation tissue — formation supported by flavonoids in wound healing
- aryl hydrocarbon receptor — activated by some flavonoids to support barrier function
- NRF2 — transcription factor activated by flavonoids for antioxidant response
- COX-2 — enzyme inhibited by flavonoids to reduce inflammation
- cruciferous vegetables — dietary source of flavonoids and indoles
- microbiome — required to metabolize flavonoid glycosides to bioavailable forms
- inflammation — reduced by flavonoid inhibition of inflammatory enzymes
- wound healing — supported by flavonoid effects on angiogenesis and collagen
- Alzheimer's disease — risk reduced by flavonoid inhibition of periodontal-brain pathway
- rheumatoid arthritis — linked to periodontal iron dysregulation prevented by flavonoids
- cardiovascular disease — risk reduced by flavonoid anti-inflammatory effects
- Calendula — herbal source of flavonoids for wound healing
- luteolin — specific flavonoid with strongest gingipain inhibition