Sunbathers may soon be closer to hitting the beach or pool without having to lather up with sunblock thanks to a team of researchers led by Dr. Paul Long at King’s College London who recently discovered how natural sunscreen compounds are made by coral. The goal of the research is to understand the genetic and biochemical basis on how natural sunscreens are made with the vision of developing non-topical commercial sun protection products, potentially in the form of tablets. This would eliminate the oily mess that’s made using topical lotions and also reduce the struggle to apply to hard-to-reach places like one’s back. The discovery could also prompt efforts to bioengineer crop plants to be more UV-tolerant, especially in sunlight-intense areas of the world.

This month, 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, a collaboration with Dr. Walter Dunlap from the Australian Institute for Marine Science and Professor Malcolm Shick from the University of Maine, USA.

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 needs sunlight to work, corals must live in shallow water, which means they are vulnerable to sunburn.

According to Dr. Long: ‘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 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 used to produce UV-tolerant crop plants capable of withstanding harsh tropical UV light.

‘The part algae play in protecting itself 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 utilise their shikimate pathway to make these natural sunscreens,’ said 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.

Read more from the official press release by King's College London.