Photochemoprevention of UVB-induced skin carcinogenesis in SKH-1 mice by brown algae polyphenols

Int J Cancer. 2006 Dec 15;119(12):2742-9. doi: 10.1002/ijc.22147.

Abstract

Chronic exposure of the skin to ultraviolet B (UVB) radiation induces oxidative stress, which plays a crucial role in the induction of skin cancer. In this study, the effect of dietary feeding and topical application of brown algae polyphenols on UVB radiation-induced skin carcinogenesis in SKH-1 mice was investigated. SKH-1 hairless mice were randomly divided into 9 groups, including control, UVB control and treatment groups. They were treated orally (0.1% and 0.5% with AIN-76 diet, w/w) and topically (3 and 6 mg/0.2 ml of vehicle) with brown algae polyphenols and irradiated with UVB for 26 weeks. Dietary feeding (0.1% and 0.5%) of brown algae polyphenols significantly reduced tumor multiplicity (45% and 56%) and tumor volume (54% and 65%), and topical administration (3 and 6 mg) significantly decreased tumor multiplicity (60% and 46%) and tumor volume (66% and 57%), respectively, per tumor-bearing mouse. Dietary feeding and topical administration of the polyphenols also inhibited tumor incidence by 6% and 21%, respectively, but the results were not significant. Dietary and topical administration of the polyphenols markedly inhibited cyclooxygenase-2 activity and cell proliferation. These observations show that brown algae polyphenols have an antiphotocarcinogenic effect which may be associated with the prevention of UVB-induced oxidative stress, inflammation, and cell proliferation in the skin.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Administration, Cutaneous
  • Administration, Oral
  • Animals
  • Benzofurans / administration & dosage
  • Benzofurans / chemistry
  • Benzofurans / pharmacology
  • Blotting, Western
  • Cell Proliferation / drug effects
  • Cell Proliferation / radiation effects
  • Cyclooxygenase 2 / genetics
  • Cyclooxygenase 2 / metabolism
  • Dinoprostone / metabolism
  • Dioxins / administration & dosage
  • Dioxins / chemistry
  • Dioxins / pharmacology
  • Epidermis / drug effects
  • Epidermis / metabolism
  • Epidermis / radiation effects
  • Female
  • Flavonoids / administration & dosage
  • Flavonoids / chemistry
  • Flavonoids / pharmacology*
  • Gene Expression / drug effects
  • Gene Expression / radiation effects
  • Immunohistochemistry
  • Mice
  • Molecular Structure
  • Neoplasms, Radiation-Induced / genetics
  • Neoplasms, Radiation-Induced / metabolism
  • Neoplasms, Radiation-Induced / prevention & control
  • Phaeophyceae / chemistry*
  • Phenols / administration & dosage
  • Phenols / chemistry
  • Phenols / pharmacology*
  • Polyphenols
  • Proliferating Cell Nuclear Antigen / analysis
  • Random Allocation
  • Reverse Transcriptase Polymerase Chain Reaction
  • Skin / drug effects*
  • Skin / pathology
  • Skin / radiation effects
  • Skin Neoplasms / etiology
  • Skin Neoplasms / metabolism
  • Skin Neoplasms / prevention & control*
  • Ultraviolet Rays / adverse effects*

Substances

  • Benzofurans
  • Dioxins
  • Flavonoids
  • Phenols
  • Polyphenols
  • Proliferating Cell Nuclear Antigen
  • dieckol
  • 6,6'-bieckol
  • eckol
  • Cyclooxygenase 2
  • Dinoprostone