Oceans occupies 70 per cent of the Earth’s surface. It gives us high protein fish, omega-3 fatty acids. The seaweeds are an excellent source of polysaccharides, vitamins and nutrients. Besides, it is a rich resource of new pharmaceuticals.

Ocean creatures are sources of many toxic compounds and these in some senses have proven a boon for us. In order to protect themselves from these toxic chemicals marine organisms develop pharmaceutical. More than 20,000 compounds have been isolated from the sea in the last three decades.

Marine sponges are a rich resource of many anticancer compounds. The Caribbean sponge Cryptotethya crypta gave us a novel compound spongothymidine which led to the development of a whole class of drugs that treat cancer and viral diseases.

Zidovudine fights the AIDS virus. Cytosine arabinoside has the potential for use in the treatment of leukemias and lymphomas. Antiviral acyclovir speeds the healing of eczema and some herpes viruses. Pseudopterosin, an anti-inflammatory substance obtained from the soft coral Pseudopterogorgonia elisabethae can be used in skin care formulations.

The marine coral derived hydroxyapatite is being used as material for bone implantation as well as an aid for regrowth and repair. Horse-shoe crab blood has given us a more time-effective method to test endotoxin contamination in medicines and medical appliances. The polysaccharides chitin and chitosan derived from marine crustaceans can be used as poultice in medical applications.

Marine organisms are also potential resource of new antibiotics. Vibrio fischeri, a bioluminescent bacterium, produces light and has symbiotic relation with some marine animals. By producing light, the bacterium helps its host to lure prey, scare enemies, and attract mates. The host, in return for this favour, provides the symbiotic bacteria with food. Vibrio fischeri forms a quorum dense enough to glow in the dark.

This phenomenon of ‘quorum sensing’— or a sort of communication between bacteria using chemical signal molecules – shows us a new way to combat bacterial infection. Quorum sensing in other type of bacteria, however, can also make people sick by producing toxins and repelling immune responses. From an understanding of how quorum sensing makes people sick, researchers are finding new insights for the treatment of bacterial infection.

This approach may lead to the development of new class of lesser resistant antibiotics that can disrupt the signalling system of microbial communities or disperse biofilms after they form. Marine organisms (such as sea squirts, sharks) have helped us in identifying the causes of many hitherto unknown diseases. For example, sea urchins have increased our understanding of how cells divide and thus helping researchers in the diagnosis and treatment of cancer.

Marine-based micro-organisms are another rich source of biomedicine. According to a report of the US Academy of Sciences as many as 99 per cent of the micro-organisms in the ocean have not yet been studied for their potential commercial applications. This vast and untapped resource needs to be tapped.

Despite intensive research in the area in the last four decades, there are a few approved marine based pharmaceuticals in the market. As Reeta Colwell, former director of US-based National Science foundation says “From the small number of new products that exist today, I would say the results of the revolution are unrealised. That is our challenge”

The writer is a biotechnologist and ED, Birla Institute of Scientific Research, Jaipur