L-Tryptophan as a Novel Potential Pharmacological Treatment for Wound Healing via Aryl Hydrocarbon Receptor Activation

Dermatology. 2015;230(4):332-9. doi: 10.1159/000371876. Epub 2015 Mar 11.


Background: The aryl hydrocarbon receptor has been shown to be involved in wound healing.

Objective: The aim of this study was to assess the effect of tryptophan on wound healing in vitro and in a clinical trial.

Methods: The ability of tryptophan and 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) to increase wound healing was assessed in an in vitro scratch wound model in human keratinocytes. Topical tryptophan and vehicle were assessed for 12 weeks in 51 patients with lower limb ulcers that were resistant to conventional therapies.

Results: TCDD 0.1 nM and tryptophan 1 µM increased the rate of scratch recovery in a culture model. Topical tryptophan induced stronger pain relief and faster re-epithelialization than its vehicle in patients with lower limb ulcers.

Conclusion: Tryptophan shows promising potential as a novel topical treatment for wound healing.

Publication types

  • Randomized Controlled Trial

MeSH terms

  • Administration, Cutaneous
  • Aged
  • Aged, 80 and over
  • Carbazoles / pharmacology
  • Cytochrome P-450 CYP1A1 / metabolism
  • Female
  • Hep G2 Cells
  • Humans
  • Keratinocytes / drug effects
  • Keratinocytes / physiology
  • Leg Ulcer / complications
  • Leg Ulcer / drug therapy*
  • Male
  • Pain / drug therapy
  • Pain / etiology
  • Polychlorinated Dibenzodioxins / pharmacology
  • Prospective Studies
  • Re-Epithelialization / drug effects*
  • Receptors, Aryl Hydrocarbon / metabolism*
  • Signal Transduction / drug effects
  • Tryptophan / pharmacology
  • Tryptophan / therapeutic use*
  • Wound Healing / drug effects*
  • Wound Healing / physiology


  • 6-formylindolo(3,2-b)carbazole
  • Carbazoles
  • Polychlorinated Dibenzodioxins
  • Receptors, Aryl Hydrocarbon
  • Tryptophan
  • Cytochrome P-450 CYP1A1