Right off North Carolina’s coast, just below the water’s surface, is a whole world, largely undiscovered. A world that encompasses many beautiful animals unlike anything found on land. If you were to swim in or fish off the coast, you probably wouldn’t notice the multitude of creatures floating along beside you. By attaching themselves to seaweed, for instance, small marine organisms become very inconspicuous.

Like the creatures of the land, the creatures of the sea have evolved ways to survive: how to find food, how to endure the waves and the wind, how to defend themselves from predators.

And they’ve got all sorts of systems worked out,” says Niels Lindquist, associate professor of marine sciences. “Some of the smallest creatures actually have some of the best survival systems.”

Some hydroids—small marine animals similar to coral—produce chemicals that deter fish from eating them. Jellyfish, man-o-war, and some other varieties of hydroids give off powerful stinging sensations to keep away enemies. Others, such as nudibranchs, eat chemically defended sponges or sea squirts and absorb their chemical defenses to protect themselves.

It turns out that what helps these creatures fend off predators could help us too. Within the past 20 years or so, researchers have discovered that these chemical defenses have the potential to serve as antibiotics, pain suppressors, anti-inflammatory agents, molecular probes, skin-care products, sunscreens, and anti-cancer agents.

But discovering the usefulness of these defenses often comes by accident. That’s what happened to Lindquist and Mark Hay, professor of marine sciences, who discovered a hydroid that has very strong UV-absorbing compounds that could possibly be used in sunscreen products.

Lindquist and Hay are marine ecologists—they study how sea creatures interact with each other and how they respond to their environments. They are especially interested in the smaller, soft-bodied creatures, which attach themselves to the bottom and don’t move. “Invertebrates, like crustaceans that are highly mobile or like snails that have hard shells, don’t produce unusual chemicals,” Lindquist says. “It’s the soft-bodied animals like sponges, soft corals, and sea squirts that can’t get up and run away that are typically the ones with a lot of bioactive chemistry. They have to have some way of defending themselves against predators.”

The hydroids Lindquist and Hay study live attached to a particular type of seaweed common to the western Atlantic ocean. Known as Sargassum, this seaweed community houses all types of species, including several different varieties of hydroids—many of which serve as fish food. Filefish, abundant in the Sargassum community, find hydroids very palatable, with one exception: they do not care for the hydroid called Tridentata marginata.

Lindquist, Hay, and graduate student Jay Stachowicz wanted to know why. They thought the hydroid might have some type of chemical defense that deterred the fish. To find out, they set up some feeding experiments. Because it’s difficult to perform these experiments in the open ocean, Lindquist and Stachowicz brought the animals to a wet lab, which has a flow-through seawater system. There, researchers can easily work with a variety of sea creatures.

To run the experiments, Lindquist and Stachowicz take various hydroids, including Tridentata marginata, place them in organic solvents, and then grind them up. They do this to get to the crude organic extract of each hydroid and the unique compounds each contains.

Then they take the crude extracts and mix each with a food that the filefish would normally eat. After repeated attempts at getting the fish to eat the extracts, the fish still reject any food that contains the extract of Tridentata marginata. From this extract, Lindquist and Stachowicz isolated the single compound—tridentatol A—that the fish won’t eat. Lindquist then figured out its molecular structure, as well as the molecular structures for several related compounds—tridentatols B-D—that the fish would eat.

Interestingly, the structures for all the compounds are very similar. Lindquist still doesn’t know why the fish won’t eat tri-dentatol A, but he did discover something unique that all of the tridentatols had in common.

While Lindquist and Stacho-wicz were isolating tridentatol A, an instrument used in the process showed that all of the extracted compounds, or tri-dentatols, broadly absorb both ultra-violet (UV)-A and UV-B radiation, which are the sun’s harmful UV rays striking us on earth. Since creatures producing these compounds float along with the seaweed near the water’s surface, Lindquist believes that tridentatols help protect the hydroid from overexposure to the sun.

Compared to compounds found in commercial sunscreens, these tridentatols could provide greater protection. Most sunscreens on the market, for instance, only protect fully against UV-B rays. While UV-B rays are the ones that cause sunburn and skin cancer, dermatologists believe overexposure to UV-A rays specifically increases the risk of melanoma—the most deadly skin cancer.

Realizing they were possibly onto something, Lindquist and Hay filed a report of invention with the university’s Office of Technology Development.

Finding a company willing to take on their discovery was quite a challenge. Companies that already produced sunscreens weren’t willing to participate because, according to the FDA, sunscreens are drugs, which require extensive testing in order to get FDA approval. Most companies didn’t want to invest the time and money.

But Lindquist persevered and finally found a company—Coastal Plantations International—that was as excited as he was about the possibility of creating a stronger sunscreen using natural products from a marine organism. It will probably take several years before the company is able to get FDA approval, but both parties feel strongly that it will be worth it.

In the meantime, the company needs to come up with the best way of produc-ing enough tridantatols to put in sunscreen products. “Just imagine all of those little bottles of sunscreen on the shelves in department stores and grocery stores,” says Lindquist. “A bottle of sunscreen with a sun protection factor (SPF) of 45, for instance, is probably a quarter to a third UV-absorbing ingredients.”

There are a couple of options Coastal Plantations will have to weigh. They can either figure out how to synthesize the compounds, or they can extract them directly from the hydroid.

Extracting the compounds from the hydroid would require a lot of animals: the hydroids would have to be grown in massive quantities in order to produce enough tridentatols, or active ingredient. This would probably be a fairly costly method because it would require the upkeep of all of these tiny creatures. But the company isn’t ruling out the possibility yet.

To synthesize the compounds, scientists need to keep in mind that they will have to make them simple and affordable, so they can compete with other products on the market. “Right now,” Lindquist says, “sunscreen companies can buy a pound of some UV-absorbing sunscreen ingredients for only twenty to thirty dollars. We have an advantage because tridantatols have a broader UV absorption than products currently on the market, (see chart, page 33) but we will still need to make them economical to produce.”

Lindquist is optimistic. “There’s a growing interest in the use of natural compounds with desirable biological activities in consumer products,” he says. “They’re great materials that enhance a product’s consumer appeal.”

Consequently, both research institutions and companies are taking the study of marine natural products seriously. The National Cancer Institute, for instance, supports a great deal of research on anticancer and antiviral marine natural products. Like Lindquist, they recognize that the study of marine organisms provides a valuable new source of possible pharmaceutical products.

Lindquist didn’t start out looking for a marketable natural product, but he definitely sees the benefit. In the recent push toward applied science, it has become increasingly important for scientists to be able to take their findings from the lab to the marketplace. Often, it’s how they get their research sponsored. Agencies and companies are more willing to sponsor research if they know it has the potential to lead to something marketable.

And researchers can profit too. Each time these compounds are sold in a product, Lindquist and Hay will receive royalties. A pleasant surprise for two researchers who just wanted to find out how some sea critters defend themselves against their predators.

Catherine House was formerly a staff contributor for Endeavors.

Niels Lindquist, Mark Hay, and Jay Stachowicz all work at the Institute of Marine Sciences in Morehead City. On October 30, the Institute celebrated its 50th anniversary and dedicated a new Coastal Processes and Environmental Health Laboratory wing there.

The Office of Technology Development (OTD) is the only UNC-CH office authorized to execute license agreements with companies. For more information on reporting inventions, contact OTD at 919/966-3929.