Traditional Chinese medicine derived from plants in the Indigofera genus (also Polygonum tinctorium, Isatis indigotica), containing high concentrations of indole compounds (particularly indirubin and indigo) that function as potent aryl hydrocarbon receptor (AhR) agonists. Used therapeutically in inflammatory bowel disease, particularly ulcerative colitis.
Indigo naturalis works primarily through AhR activation: (1) Indole compounds (indirubin, tryptanthrin, indigo) bind AhR and translocate to nucleus, activating transcription of: IL-10 (anti-inflammatory), IL-22 (barrier repair), tight junction proteins (occludin, ZO-1), antimicrobial peptides (defensins), (2) Differentiates Th17 cells toward regulatory phenotype, (3) Expands Treg populations for immune tolerance, (4) Supports goblet cell differentiation and mucus production, (5) Modulates tryptophan metabolism—shifts away from kynurenine pathway (which produces quinolinic acid in neuroinflammation) toward indole pathway, (6) Direct anti-inflammatory effects independent of AhR. Clinical trials show significant efficacy in ulcerative colitis with remission rates 60-70% in some studies.
Indigo naturalis provides therapeutic AhR activation for patients with IBD, barrier dysfunction, or AhR deficiency. It's particularly valuable when: (1) Patients cannot consume adequate cruciferous vegetables, (2) Dysbiosis prevents endogenous indole production, (3) Pharmaceutical immunosuppression is being tapered, (4) Barrier restoration is priority. Typical dose: 1-2 grams daily with meals. Important: quality matters—contamination with heavy metals or inappropriate processing can occur; use pharmaceutical-grade extracts. Clinical monitoring required as some formulations associated with pulmonary arterial hypertension (rare but serious adverse effect).
- Derived from Indigofera, Polygonum tinctorium, or Isatis indigotica plants
- Contains indole AhR agonists: indirubin, indigo, tryptanthrin
- Clinical trials show 60-70% remission rates in ulcerative colitis
- Activates AhR, inducing IL-10, IL-22, tight junctions, defensins
- Expands Tregs and promotes immune tolerance
- Supports goblet cell differentiation and mucus production
- Shifts tryptophan metabolism away from kynurenine pathway
- Typical dose: 1-2 grams daily with meals
- Rare but serious adverse effect: pulmonary arterial hypertension (requires monitoring)
- aryl hydrocarbon receptor — Indigo naturalis provides potent AhR agonists
- indole — Indigo naturalis is concentrated source of indole AhR ligands
- inflammatory bowel disease — primary therapeutic indication for Indigo naturalis
- ulcerative colitis — 60-70% remission rates with Indigo naturalis in trials
- IL-10 — anti-inflammatory cytokine upregulated by Indigo naturalis via AhR
- IL-22 — barrier repair cytokine induced by Indigo naturalis
- tight junctions — proteins upregulated by Indigo naturalis improving barrier
- Tregs — expanded by Indigo naturalis for immune tolerance
- goblet cells — differentiation supported by AhR activation from Indigo naturalis
- mucus layer — production increased by Indigo naturalis
- defensins — antimicrobial peptides upregulated by Indigo naturalis
- tryptophan — metabolism shifted from kynurenine to indole pathway
- kynurenine — pathway downregulated by Indigo naturalis AhR activation
- neuroinflammation — prevented by shifting tryptophan away from quinolinic acid production
- cruciferous vegetables — Indigo naturalis provides alternative AhR activation when vegetables insufficient
- dysbiosis — Indigo naturalis compensates when gut bacteria cannot produce indoles
- leaky gut — barrier function restored by Indigo naturalis tight junction upregulation
- immune tolerance — promoted by Indigo naturalis via Treg expansion
- occludin — tight junction protein upregulated by Indigo naturalis
- ZO-1 — tight junction protein increased by Indigo naturalis AhR activation