Diving for Cures

  • Researchers are hoping to find cures underwater in corals and sponges. (Photo courtesy of NOAA)

Making medicine from things
found in nature isn’t a new
idea. Think, aspirin – which
originally came from the bark
of willow trees. Now drugs
derived from ocean animals are
slowly making their way onto
shelves. Samara Freemark talks to a researcher
who helps get them there:

Transcript

Making medicine from things
found in nature isn’t a new
idea. Think, aspirin – which
originally came from the bark
of willow trees. Now drugs
derived from ocean animals are
slowly making their way onto
shelves. Samara Freemark talks to a researcher
who helps get them there:

Mark Slattery is trying to find a cure for cancer. Slattery is a pharmacology professor at the University of Mississippi. But he doesn’t really spend much time in the lab. Instead, he’s usually in a wetsuit, scuba diving off the coasts of places like Guam and Antarctica.

He’s taking samples from tens of thousands of corals and sponges. He’s looking for that one special species that might make a chemical that could cure disease. He calls it, ‘diving for cures.’

“In many ways, it’s like going out and playing your super lotto or whatever. You pick your eight numbers and you see if you hit or not.”

The idea is pretty simple. A third of the medicines on shelves today were derived from plants and animals that live on land. So ocean researchers got to thinking that the organisms they studied probably also produced a lot of useful chemicals.

Take corals and sponges. They can’t run away from predators, so instead they squirt out chemicals that poison the fish that try to take a bite out of them. Marc Slattery says those toxins are bad for the fish – but they could be good for people.

“Those particular compounds that tell a fish “not today” are the same ones that might tell the AIDS virus “you can’t replicate” or tell a cancer cell “you’re dead” or those kinds of things.”

So Slattery and other researchers like him clip off bits of sponges and corals. When they get back to the lab they extract the chemicals, which is a nice way of saying…

“Stick it in a blender with methanol and ethyl acetate and hexanes and all those sorts of things you used in organic chemistry lab, and you throw away the dead sponge, and the tarry residue that’s left is sort of the biochemistry that came out of that sponge.”

“So you make a sponge smoothie?”

“Exactly.”

Once they’ve extracted the chemicals, researchers test to see if they have any human application. If a compound looks promising, it moves on to clinical trials. Those trials can take decades, which is why ocean-derived drugs are only now starting to hit the market. So far only two have been approved for use in the United States: a painkiller, and a cancer drug marketed by Johnson and Johnson.

I wondered how ocean conservationists felt about diving for cures. So I called up Sandra Brooke. She studies corals at the Marine Conservation Biology Institute. Brooke says she does worry that diving for cures could lead to over-harvesting.

“Once something becomes valuable to people, there’s a resistance to closing access to it. It becomes harder to regulate it.”

But she says corals are under much greater and much more immediate threats. The biggest culprit is industrial trawling. That’s when fisherman scrape reefs off the ocean floor so they can get to the fish.

“It’s just like the clear cutting of the forest, but on a much vaster scale. They are deliberately mowing down these deepwater coral ecosystems that are thousands and thousands of years old – some of the oldest animals ever measured. And that’s not going to come back – not in our lifetimes, not in many lifetimes.”

There’s also the fact that oceans are changing as the climate does. Those changes mean corals are becoming weaker. Marc Slattery thinks he might be seeing that in a Pacific reef he’s been studying for fifteen years.

“When we went back and started looking at it, we noticed that there was a change in the chemistry through time. As things have heated up on the reefs, there’s a physiological effect that has cascaded down into their ability to produce the chemistry we’re used to seeing. Early on it was so apparent, it was always there, and now they seem to be able to produce less of it.”

That’s means that today the cure for cancer might be out there in some coral reef, but it could be gone tomorrow.

For The Environment Report, I’m Samara Freemark.

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