The International Year of the Reef 2008 is a worldwide campaign to raise awareness of the value and importance of coral reefs and threats to their sustainability, and to motivate people to take action to protect them.  To this end, over the next year, articles about coral reefs will be become a regular feature in this magazine.     Oceans contain the greatest biodiversity in the world, yet the resources they hold are far from being fully understood.  Coral reefs alone provide a rich source of biological and chemical diversity, containing up to 1,000 different species per square metre.  The reefs’ chemical diversity could serve as a unique source of natural products, holding potential for pharmaceuticals, dietary supplements, pesticides, cosmetics and other novel commercial products.

The unique medicinal properties of coral reef organisms were recognized by Eastern cultures as early as the 14th century.  Today, some of the species remain in high demand for use in traditional medicines.  For example, in China and Japan, tonics and medicines derived from seahorses are used to treat a wide range of ailments including respiratory and circulatory problems, kidney and liver diseases and throat infections.

Of all the medicines in use today, almost 50% are derived from natural products such as terrestrial plants, animals and microorganisms, but the number of marine-derived products is increasing rapidly.  Some of the first medicines derived from coral reefs include antiviral drugs Ara-A and AZT, and the anti-cancer agents in the agent Ara-C that were developed from the extracts of sponges found on a Caribbean reef.  Dolostatin 10 was isolated from a sea hare in the Indian Ocean and is undergoing clinical trials for use in treatment of breast cancers, tumours and leukemia.  In fact, dozens of promising products from marine organisms are being advanced, including a cancer therapy made from algae and a painkiller taken from the venom in a cone shell.

But precisely how do these organisms have the potential to cure an incurable disease? Marine organisms engage in a form of chemical warfare, using bioactive compounds to deter predation, escape environmental perturbations, fight disease and prevent overgrowth by fouling and competing organisms.  Some marine species even use potent toxins to catch their prey by paralyzing them. If these chemicals can be isolated, they have the potential to be used in a number of commercial products.

Less than 10% of coral reef biodiversity is known, and only a very small percentage of these organisms have been explored as a source for biomedical products.  Unfortunately, with the decline of coral reefs around the world and the absence of effective management of coral reefs and the resources they contain, many species that hold promise as new sources of biomedical materials for pharmaceuticals and other products may be lost before scientists have the opportunity to evaluate them for such uses.  So if the decline of coral reefs around the world doesn’t seem relevant to you personally, remember the vast potential they possess for the field of medicine.

Photo courtesy of NURC/UNCW and NOAA/FGBNMS.

The venom from cone shells have been isolated to create a painkiller ten times more powerful than morphine but without the addictive side effects. Photo courtesy of the National Oceanic and Atmospheric Administration/Department of Commerce photo library (http://www.photolib.noaa.gov).