FWD:PM-sea snail could aid chronic pain treatments

Sea snail could aid chronic pain treatments PRINT FRIENDLY EMAIL STORY
PM - Monday, 11 December , 2006 18:42:00
Reporter: Donna Field
MARK COLVIN: A deadly sea snail found on the Great Barrier Reef could revolutionise treatment for sufferers from chronic pain.

Scientists at the University of Queensland have found that the toxin, which the snail uses to hunt its prey, can accurately target pain without the severe side effects of other pain treatments.

The research is in its early stages, but the team believes that it will be able to develop a drug within a decade.

Researcher Doctor Jenny Ekberg has told Donna Field that with one in five Australians suffering from chronic pain at some point in their lives, the potential benefits are enormous.

JENNY EKBERG: I have discovered that from a sea snail living on the Great Barrier Reef, that normally is hunting fish, you can isolate a toxin that can be used to treat chronic pain states.

DONNA FIELD: Why is this such a significant thing?

JENNY EKBERG: Because normal conventional pain treatments have a lot of problems - you can't take enormous amounts of morphine, for example, because you would die.

And lots of these conventional pain treatments such as local anaesthetics have serious side effects which can lead to death or more minor problems such as motor problems, movement problems, and drowsiness.

But this particular toxin that we have isolated from the snail is very, very specific. It targets a receptor in nerve cells, which is involved in pain and nothing else, so you only get pain relief, but no side effects.

DONNA FIELD: What kind of trials have you done on it so far?

JENNY EKBERG: So far we have only done it in animal models. But the next step is of course to move on to clinical trials with humans.

DONNA FIELD: And how long will it be before you can do that?

JENNY EKBERG: Actually first of all we have to learn to synthesise this toxin properly, because we don't get enough from the snails, so we have to learn to make it artificially, and we're doing that at the moment.

After that, a couple of years until it's in clinical trials, and then... it's a long process when you create a new drug, it's usually about 10 years until it could be available on the market.

DONNA FIELD: How did you actually go about finding that this particular sea snail from the Great Barrier Reef had these capabilities?

JENNY EKBERG: You actually don't know first, you have to screen first crude venom, which means it's a venom directly from the snail, and then you see an interesting activity, and then you start trying to isolate what it is that it has its interesting activity. And in this case it was to block a receptor in nerve cells, which is involved in pain.

DONNA FIELD: So instead of morphine, what other medicines could this replace potentially?

JENNY EKBERG: All pain treatments for severe pain, such as local anaesthetics, for example, and yeah, as I said, morphine. There's nothing else that really is that good. It's usually for morphine replacement.

DONNA FIELD: So it could be used in local anaesthetics?

JENNY EKBERG: Yeah, it could but because it probably will be quite expensive to make, I don't think that they would just give it to anybody. I think that the goal is to give it to people who have pretty severe pain.

So this is particularly for people who suffer a lot, quite a lot of people suffer from chronic pain, for example people with diabetes have lots of problems with something called neuropathic pain, which is caused by damage to nerves, due to the diabetes, and this could be extremely helpful for such people.

DONNA FIELD: Now, this marine snail, what does it look like?

JENNY EKBERG: It's really beautiful. It's got... it's called conus marmoreus. It's got a beautiful texture, it's brown and white, and it's very nice. So that's why people, when they see it on the Barrier Reef, you shouldn't pick it because it's also very dangerous - if you get stung by it you can die.

DONNA FIELD: So currently it uses this toxin as a defence mechanism. Is that right?

JENNY EKBERG: That's true. Defence and hunting. It hunts other snails or fish with a harpoon-like apparatus, from which it injects its venom into the prey. And that's why this is acting on the nervous system, because it's evolved to become efficient in immobilising its prey.

DONNA FIELD: So this marine snail that you found this breakthrough in comes from the Great Barrier Reef? Is the reef a source of a lot of potential medical cures and treatments, in your opinion?

JENNY EKBERG: Absolutely. If you just look at sea snails, they're called, from the genus conus, which are the one that we're looking at, that have these toxins, we think that we know about one per cent of the potential toxins that could be found in these snails, and it's not just interesting for pain, also many other diseases including dementia or depression, et cetera, could be targeted, potentially, by these sea snails.

MARK COLVIN: Dr Jenny Ekberg from the University of Queensland, with Donna Field.