Cancer Research Lab

Feb. 2 (iVillage Total Health) — A new study using brown algae to treat mice may show promise for millions of Americans who develop skin cancer each year. Ohio State University scientists studied the effect that topical and oral ingestion of substances from brown algae found in marine seaweed had on growth and size of non-melanoma skin tumors in mice. Results of the study were published in the December 15 issue of the International Journal of Cancer.

Non-melanoma skin cancer is the most common form of cancer in the United States, with more than 1 million cases diagnosed each year, according to the American Cancer Society. Most cases are caused by overexposure to the sun’s ultraviolet (UV) radiation. People with lightly pigmented skin and those who have previously developed skin cancer have the greatest risk of developing the condition. Non-melanoma skin cancer is curable if it is identified early, through a biopsy, and then removed through one of several methods.

The OSU researchers noted that previous studies have associated brown algae chemicals called polyphenols with cancer-fighting and antioxidant properties. The scientists used nine groups of mice, each containing 20 hairless mice that were susceptible to skin cancer caused by ultraviolet B (UVB) radiation.

Two groups received topical applications of brown algae containing either 3 milligrams (mg) or 6 mg in a mild solvent. Two other groups were fed a diet containing the algae compound in 0.1 percent or 0.5 percent concentrations. One group of control mice received no treatment but was exposed to UVB radiation.

Two groups of mice were given a standard diet with some getting UVB exposure and some without exposure. Another set of two groups received the topical brown algae applied to their skin with and without UVB exposure.

All of the treatments were administered over a two-week period followed by 24 weeks of UVB exposure. Researchers then assessed skin tumor growth and size in all mice.

They found that those exposed to UVB had an average of 8.5 tumors. Those who ingested the lower and higher doses of algae averaged only 4.7 and 3.7 tumors, respectively. The mice given the lower and higher doses of topical solvents developed 3.4 and 4.6 tumors, respectively.

Tumors were also smaller (by some 27 to 43 percent) on both sets of mice receiving brown algae compared to those that did not receive treatment.

“These compounds seemed to be dramatically effective at fairly low doses both orally and topically,” OSU principal investigator Gary D. Stoner said in a press release. “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.”

Funding for the OSU study was provided by the U.S. Department of Agriculture and the Korean Research Foundation.