The animal study indicates that chemicals called brown algae polyphenols (BAPs), which are found in a type of brown marine seaweed, might protect against skin cancers caused by ultraviolet B (UVB) radiation.
UVB radiation in sunlight is thought responsible for 90 percent of the estimated 1.3 million cases of non-melanoma skin cancer diagnosed in the United States annually.
Researchers applied the BAPs to the skin of hairless mice and fed it to the animals in their diet. In both cases, the substances reduced the number of skin tumors by up to 60 percent and their size by up to 43 percent. They also reduced inflammation.
The study, led by researchers at the Ohio State University Comprehensive Cancer Center, is published in the Dec. 15 issue of the International Journal of Cancer.
"These compounds seemed to be dramatically effective at fairly low doses both orally and topically," says principal investigator Gary D. Stoner, professor emeritus of internal medicine and a cancer chemoprevention researcher.
"These findings suggest that, even when eaten, these compounds get to skin cells and neutralize the cancer-causing oxygen radicals that are produced by UV exposure."
Laboratory research has shown that BAPs are strong antioxidants and may have anticancer properties.
For this study, Stoner and his collaborators used a strain of hairless mice that are particularly susceptible to UVB-induced skin cancer. Nine experimental groups were used, each with 20 mice.
In two groups, BAPs were applied to the skin in concentrations of 3 milligrams or 6 milligrams in a mild solvent. In two other groups, BAPs made up 0.1 percent or 0.5 percent of the diet.
A group of untreated control mice was also exposed to UVB.
The remaining groups were additional co
Source:Ohio State University