Suppression of gamma-tocotrienol on UVB induced inflammation in HaCaT keratinocytes and HR-1 hairless mice via inflammatory mediators multiple signaling

J Agric Food Chem. 2010 Jun 9;58(11):7013-20. doi: 10.1021/jf100691g.

Abstract

Tocopherol (Toc) such as alpha-Toc has been expected to act as photochemopreventive agent of skin, but the effect of the other vitamin E forms [tocotrienols (T3)] has not been fully understood. We evaluated the anti-inflammatory effect of T3 on UVB-induced inflammatory reaction using immortalized human keratinocytes and hairless mice. gamma-T3 suppressed UVB-induced PGE(2) production while similar alpha-Toc doses had no effect. The anti-inflammatory actions of gamma-T3 were explained by its ability to reduce UVB-induced inflammatory gene and protein expression [cyclooxgenase-2 (COX-2), interleukin (IL)-1beta, IL-6, and monocyte chemotactic protein-1]. Western blot analysis revealed gamma-T3 inhibited p38, extracellular signal-regulated kinase, and c-Jun N-terminal kinase/stress-activated protein kinase activation. In HR-1 hairless mice, oral T3 suppressed UVB-induced changes in skin thickness, COX-2 protein expression, and hyperplasia, but alpha-Toc did not. These results suggest T3 has potential use to protect against UVB-induced skin inflammation.

MeSH terms

  • Animals
  • Cells, Cultured
  • Chemokine CCL2 / genetics
  • Chemokine CCL2 / immunology
  • Chromans / pharmacology*
  • Cyclooxygenase 2 / genetics
  • Cyclooxygenase 2 / metabolism
  • Down-Regulation*
  • Female
  • Gene Expression / drug effects
  • Gene Expression / radiation effects
  • Humans
  • Inflammation Mediators / immunology*
  • Interleukin-6 / genetics
  • Interleukin-6 / immunology
  • Keratinocytes / drug effects
  • Keratinocytes / immunology*
  • Keratinocytes / metabolism
  • Keratinocytes / radiation effects*
  • MAP Kinase Signaling System / drug effects
  • MAP Kinase Signaling System / radiation effects
  • Mice
  • Mice, Hairless
  • Radiation-Protective Agents / pharmacology*
  • Ultraviolet Rays
  • Vitamin E / analogs & derivatives*
  • Vitamin E / pharmacology

Substances

  • Chemokine CCL2
  • Chromans
  • Inflammation Mediators
  • Interleukin-6
  • Radiation-Protective Agents
  • Vitamin E
  • plastochromanol 8
  • Cyclooxygenase 2