Sea Diving for Medicine

With the number of infectious diseases escalating, scientists are searching everywhere for cures, including in our oceans. Although water covers 70% of the earth’s surface, only five percent of this environment has been explored. This huge unexplored resource may be a key to the discovery of new antibiotics and other medicines.

Natural Medicines

Nearly half of the medications introduced during the past 30 years are derived from natural products or their derivatives. Plantderived compounds have a long history of clinical use, may be more easily tolerated and accepted, and are typically used in ways similar to their original ethnopharmacological purposes.

To date, between 35,000 and 70,000 plant species have been screened for medicinal use, and more than 10% of the World Health Organization’s list of “basic and essential” drugs come from flowering plants. But opportunities exist in the biodiversity of ocean organisms for scientists to discover and develop new medicines. Drugs derived from ocean-dwelling organisms are already helping to combat cancer, HIV, tuberculosis, dengue fever, and malaria.

Ocean Exploration

Innovations like modern snorkeling, SCUBA gear, manned submersibles, and remotely operated vehicles have increased our access to the marine world and have led to the isolation and identification of thousands of unique and bioactive products. The current global marine pharmaceutical pipeline includes drugs approved by the U.S. Food and Drug Administration (FDA), EU-registered drugs, natural products or derivatives, and a number of other marine chemicals still in development.

Scientists from the U.S. National Oceanic and Atmospheric Administration (NOAA) are collecting and studying sponges, corals, and other marine organisms. They have discovered a chemical that breaks down the shield that protects bacteria from antibiotics, which could be a useful helper drug for antibiotics that have become ineffective. These NOAA researchers have also extracted antimicrobial chemicals from corals and sponges and are developing methods to replicate those chemicals, which will reduce the negative environmental impact of continued marine harvesting.

Other Discoveries

Sponges, or Porifera, are invertebrates that lack nervous, digestive, and circulatory systems and are filter feeders: they get food and oxygen and remove wastes by maintaining a constant flow of water through their bodies. With a limited ability to defend themselves against predators, they produce fish-deterrent C-nucleosides, compounds that also possess antiviral and anticancer properties.

The term algae describes at least 30,000 species that supply food for fish and humans, oxygen for the biosphere, medicine for the healthcare industry, and fertilizers for agricultural purposes. A rich source of structurally unique natural products, green, brown, and red algae have been intensively assessed for antibacterial and antifungal activity.

Agricultural productivity has been increased by advances in pest control with synthetic chemical pesticides (SCPs), but new pesticides are needed due to the significant rise in the resistance to current agents. Considerable research has focused on the isolation of insecticidal leads from Chilean red algae and other varieties from which more than 40 active constituents have been isolated.

Sea squirts, cone snails, sharks, horseshoe crabs, and toadfish have also been the subject of studies that have led to potential treatments for conditions including nerve damage, cardiomyopathy, and cancer.

Limitless Potential

Natural products have played a vital role in improving human health and have been the drugs of choice despite newer compounds that have been created through computational and combinatorial chemistry. This world of biology offers a range of structural diversity that is still largely untapped.

Although this renewed interest in natural medicinal products and treatments brings challenges like quality control, standardization, and cost effectiveness, the new opportunities it offers scientists for research and development in various areas of science are vast.

And, if the oceans are key to the discovery of new medicines, scientists remind us that protecting the quality of our planet’s water and its inhabitants may be more important than ever.