Solar ultraviolet-induced erythema in human skin and nuclear factor-kappa-B-dependent gene expression in keratinocytes are modulated by a French maritime pine bark extract

Free Radic Biol Med. 2001 Jan 15;30(2):154-60. doi: 10.1016/s0891-5849(00)00445-7.


The procyanidin-rich French maritime pine bark extract Pycnogenol (PBE) has been investigated for its effect in protecting human skin against solar UV-simulated light-induced erythema. Twenty-one volunteers were given an oral supplementation of Pycnogenol: 1.10 mg/kg body weight (b. wt.)/d for the first 4 weeks and 1.66 mg/kg b. wt./d for the next 4 weeks. The minimal erythema dose (MED) was measured twice before supplementation (baseline MED), once after the first 4 weeks of supplementation, and a last time at the end of the study. The UVR dose necessary to achieve 1 MED was significantly increased during PBE supplementation. Since the activation of the pro-inflammatory and redox-regulated transcription factor NF-kappaB is thought to play a major role in UVR-induced erythema, the effect of PBE was also investigated in the human keratinocyte cell line HaCaT. PBE, added to the cell culture medium, inhibited UVR-induced NF-kappaB-dependent gene expression in a concentration-dependent manner. However, NF-kappaB-DNA-binding activity was not prevented, suggesting that PBE affects the transactivation capacity of NF-kappaB. These data indicate that oral supplementation of PBE reduces erythema in the skin. Inhibition of NF-kappaB-dependent gene expression by PBE possibly contributes to the observed increase in MED.

Publication types

  • Clinical Trial

MeSH terms

  • Administration, Oral
  • Adolescent
  • Adult
  • Anti-Inflammatory Agents / administration & dosage
  • Anti-Inflammatory Agents / pharmacology*
  • Anti-Inflammatory Agents / therapeutic use
  • Cell Line
  • Cell Survival / drug effects
  • DNA / genetics
  • DNA / metabolism
  • Dose-Response Relationship, Radiation
  • Erythema / drug therapy
  • Erythema / metabolism
  • Erythema / pathology*
  • Female
  • Flavonoids / administration & dosage
  • Flavonoids / pharmacology*
  • Flavonoids / therapeutic use
  • Genes, Reporter
  • Humans
  • Keratinocytes / drug effects
  • Keratinocytes / metabolism
  • Keratinocytes / radiation effects*
  • Male
  • NF-kappa B / metabolism*
  • Plant Extracts / administration & dosage
  • Plant Extracts / pharmacology
  • Plant Extracts / therapeutic use
  • Protein Binding / drug effects
  • Signal Transduction / drug effects
  • Skin / drug effects
  • Skin / metabolism
  • Skin / pathology
  • Skin / radiation effects
  • Transcriptional Activation / drug effects*
  • Transcriptional Activation / radiation effects
  • Ultraviolet Rays / adverse effects*


  • Anti-Inflammatory Agents
  • Flavonoids
  • NF-kappa B
  • Plant Extracts
  • pycnogenols
  • DNA