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

• Published in: Free radical biology & medicine Vol. 30; no. 2; pp. 154 - 160
• Main Authors: Saliou, Claude, Rimbach, Gerald, Moini, Hadi, McLaughlin, Laura, Hosseini, Saeed, Lee, Jeongmin, Watson, Ronald R, Packer, Lester
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 15.01.2001
• Subjects: 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; Erythema - drug therapy; Erythema - metabolism; Erythema - pathology; Female; Flavonoids - administration & dosage; Flavonoids - pharmacology; Flavonoids - therapeutic use; Free radicals; Gene expression; Genes, Reporter; Humans; Inflammation; Keratinocyte; Keratinocytes - drug effects; Keratinocytes - metabolism; Keratinocytes - radiation effects; Male; NF-kappa B - metabolism; NF-κB; Plant Extracts - administration & dosage; Plant Extracts - pharmacology; Plant Extracts - therapeutic use; Procyanidins; Protein Binding - drug effects; Pycnogenol; Signal Transduction - drug effects; Skin; Skin - drug effects; Skin - metabolism; Skin - pathology; Skin - radiation effects; Transcriptional Activation - drug effects; Transcriptional Activation - radiation effects; Ultraviolet; Ultraviolet Rays - adverse effects; Pycnogenol; Procyanidins; Free radicals; Inflammation; b. wt; Ultraviolet; Gene expression; MED; NF-κB; PBE; EMSA; RNS; ROS; Keratinocyte; Skin; Erythema
• ISSN: 0891-5849; 1873-4596
• 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-κB 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-κB–dependent gene expression in a concentration-dependent manner. However, NF-κB–DNA-binding activity was not prevented, suggesting that PBE affects the transactivation capacity of NF-κB. These data indicate that oral supplementation of PBE reduces erythema in the skin. Inhibition of NF-κB–dependent gene expression by PBE possibly contributes to the observed increase in MED.