Chemoprevention - Experimental/Molecular: Combination Chemoprevention Photochemoprevention of UVB-induced skin carcinogenesis in SKH-1 mice by brown algae polyphenols. Hyejeong Hwang, Tong Chen, Ronald G. Nines, Hyeon-Cheol Shin and Gary D. Stoner LIVECHEM USA INC., Bellevue, WA; Ohio State University, Columbus, OH Abstract#B77 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. Frontiers in Cancer Prevention Research, 11/06 Remember we are NOT Doctors and have NO medical training. This site is like an Encylopedia - there are many pages, many links on many topics. Support our work with any size DONATION - see left side of any page - for how to donate. You can help raise awareness of CAM.