Aussie Coral Compounds Promising for Human Sunscreen

Aug. 31, 2011— -- Tropical coral from Australia's Great Barrier Reef contains natural UV blockers that might one day come in a pill that protects our eyes and skin from the sun's ravages, researchers say.

But don't toss your high-SPF lotions and creams yet. If all goes as planned, a tablet that would protect people from damaging ultraviolet radiation is probably about five years away, said Paul Long, a senior lecturer in pharmaceutical science at King's College London.

Long leads a three-year research project, financed by the British government, focused on sun-shielding compounds in Acropora microphthalma coral. He and his fellow researchers have been trying to unravel the biochemical secrets of these chemicals, extracted from coral samples gathered during night dives.

"What we have found is that the algae living within the coral makes a compound that we think is transported to the coral, which then modifies it into a sunscreen for the benefit of both the coral and the algae," Long said in a statement from King's College, which issued a news release and video about the research. "Not only does this protect them both from UV damage, but we have seen that fish that feed on the coral also benefit from this sunscreen protection, so it is clearly passed up the food chain."

Because Acropora microphthalma coral is endangered, the scientists first must create a synthetic version of the coral compounds, which could be tested on human skin samples. Long has suggested scientists might find a ready supply in excess skin discarded by plastic surgeons after tummy tucks. Only after scientists learn how the compound affects skin cells could they then begin developing a pill that would protect skin throughout the body, as well as the eyes, which also are sensitive to the effects of UV light.

Long and his colleagues began thinking a pill might work based upon observations of small fish eating coral, "like Nemo" in the animated movie "Finding Nemo," "and then larger fish would eat the smaller fish, so these compounds pass up the food chain."

One important consideration for researchers involves determining how the compounds' UV-blocking properties might interfere with the body's production of Vitamin D, often called the sunshine vitamin. Vitamin D comes either from exposure to sunlight, or from dietary supplements.

Long's longtime collaborators are J. Malcolm Shick, a marine sciences professor at the University of Maine in Orono, and Walter Dunlap, a marine research scientist at the Australian Institute for Marine Science. In 1986, Dunlap reported the discovery of UV-absorbing sunscreens in shallow-water coral. The three have published several papers on the biochemical processes and genes responsible for Acropora's response to solar radiation, as well as the phenomenon of coral bleaching. Long also said a long-term goal of the research project is to help make crops in Third World countries more able to withstand strong UV light.

A pill based on coral's natural UV blockers wouldn't be the first sunscreen pill to offer protection from the inside out. A dietary supplement called Heliocare contains green tea, beta-carotene and Polypodium leucotomos, a tropical fern extract long used for psoriasis and eczema. However, dermatologists say its skin-protective antioxidants don't take the place of topical sunscreens, but may make the sun less vulnerable to UV damage. A bottle of 60 Heliocare pills runs about $50.