title: Photochemoprevention of UVB-induced skin carcinogenesis in SKH-1 mice by brown algae polyphenols.
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.
authors.affiliation: Chemoprevention and Support Program, Division of Hematology and Oncology, Department of Internal Medicine, College of Medicine and Public Health, The Ohio State University, Columbus, Ohio 43210, USA.
authors.forename: Hyejeong
authors.initials: H
authors.lastname: Hwang
authors.forename: Tong
authors.initials: T
authors.lastname: Chen
authors.forename: Ronald G
authors.initials: RG
authors.lastname: Nines
authors.forename: Hyeon-Cheol
authors.initials: HC
authors.lastname: Shin
authors.forename: Gary D
authors.initials: GD
authors.lastname: Stoner
mesh_terms: D000279:Administration, Cutaneous; D000284:Administration, Oral; D000818:Animals; D001572:Benzofurans / Q000008:administration & dosage / Q000737:chemistry / Q000494:pharmacology; D015153:Blotting, Western; D049109:Cell Proliferation / Q000187:drug effects / Q000528:radiation effects; D051546:Cyclooxygenase 2 / Q000235:genetics / Q000378:metabolism; D015232:Dinoprostone / Q000378:metabolism; D004147:Dioxins / Q000008:administration & dosage / Q000737:chemistry / Q000494:pharmacology; D004817:Epidermis / Q000187:drug effects / Q000378:metabolism / Q000528:radiation effects; D005260:Female; D005419:Flavonoids / Q000008:administration & dosage / Q000737:chemistry / Q000494:pharmacology*; D015870:Gene Expression / Q000187:drug effects / Q000528:radiation effects; D007150:Immunohistochemistry; D051379:Mice; D015394:Molecular Structure; D009381:Neoplasms, Radiation-Induced / Q000235:genetics / Q000378:metabolism / Q000517:prevention & control; D000459:Phaeophyceae / Q000737:chemistry*; D010636:Phenols / Q000008:administration & dosage / Q000737:chemistry / Q000494:pharmacology*; D059808:Polyphenols; D018809:Proliferating Cell Nuclear Antigen / Q000032:analysis; D011897:Random Allocation; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012867:Skin / Q000187:drug effects* / Q000473:pathology / Q000528:radiation effects; D012878:Skin Neoplasms / Q000209:etiology / Q000378:metabolism / Q000517:prevention & control*; D014466:Ultraviolet Rays / Q000009:adverse effects*
chemical_list: D001572:Benzofurans; D004147:Dioxins; D005419:Flavonoids; D010636:Phenols; D059808:Polyphenols; D018809:Proliferating Cell Nuclear Antigen; C503840:dieckol; C062360:6,6'-bieckol; C060311:eckol; D051546:Cyclooxygenase 2; D015232:Dinoprostone