Researchers at King’s College, London have discovered how coral produces a natural sunscreen to protect itself from damaging ultra-violet (UV) rays, leading scientists to believe these compounds could form the basis for developing a new type of sunscreen for people.
The team has begun to uncover the genetic and biochemical processes behind how these compounds are produced, and eventually hope to recreate them synthetically in the laboratory, for this purpose.
As part of the three-year project funded by the Biotechnology and Biological Sciences Research Council (BBSRC), the King’s team collected coral samples for analysis from the Great Barrier Reef, in collaboration with Dr. Walter Dunlap from the Australian Institute for Marine Science and Prof. Malcolm Shick from the University of Maine USA.
A unique relationship
Coral is an animal which has a unique symbiotic partnership with algae that lives inside it – the algae use photosynthesis to make food for the coral and the coral waste products are used by the algae for photosynthesis. Because photosynthesis depends on sunlight, corals must live in bright, shallow water, leaving them vulnerable to sunburn.
Dr. Paul Long, senior lecturer from the Institute of Pharmaceutical Science at King’s College London, who is leading the project, said: “We already knew that coral and some algae can protect themselves from the harsh UV rays in tropical climates by producing their own sunscreens but, until now, we didn’t know how.”
“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. 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.”
“This led us to believe that if we can determine how this compound is created and passed on, we could biosynthetically develop it in the laboratory to create a sunscreen for human use, perhaps in the form of a tablet, which would work in a similar way. We are very close to being able to reproduce this compound in the lab, and if all goes well, we would expect to test it within the next two years.”
A way of combating starvation?
A long-term goal of the King’s study is to look at whether these processes could also be used for developing sustainable agriculture in the Third World, as these natural sunscreen compounds found in coral could be utilized to produce UV-tolerant crop plants capable of withstanding harsh tropical UV light.
“The part algae play in protecting themselves and coral against UV is thought to be a biochemical pathway called the shikimate pathway, found only in microbes and plants. If we could take the part of the pathway that the coral generates, and put this into plants, we could potentially also utilize their shikimate pathway to make these natural sunscreens,” added Dr. Long.
“If we do this in crop plants that have been bred in temperate climates for high yield, but that at present would not grow in the tropics because of high exposure to sunlight, this could be a way of providing a sustainable nutrient-rich food source, particularly in need for Third World economies,” he concluded.