By studying how victims' bodies react to bites and stings, scientists are turning deadly venom into life-saving substances.

KILLER CURES

March 26, 1998|By Richard O'Mara | Richard O'Mara,SUN STAFF

Ever wake up feeling like the Tin Man after a damp night sleeping outdoors?

Your knuckles ache, your elbows, your knees, every other place where bone is joined to bone squeaks with pain?

If so, you might want to think about honeybee venom. Some people believe it relieves the pain of arthritis. The evidence for this is anecdotal. That means it's never been proved that the chemicals and enzymes and whatnot that make up honeybee venom can actually ease the agony of arthritis, or anything else.

"And," said Jack Cover, curator of "Venom: Striking Beauties," the new exhibit on venomous creatures at the National Aquarium in Baltimore, "until it's proved chemically, it isn't proved."

Still, people toil away in "Mom and Pop laboratories" here and there tediously extracting minute amounts of the venom from the selfless little insects. Why? There's a market for it, said Cover, who is also curator for all rain forest exhibits at the aquarium. It's a small market, but it's steady.

In fact, there are a lot of other dangerous substances that people have found benign uses for. Alongside the creatures at the venom exhibit is a special "medicine cabinet" displaying established and experimental drugs made from various venoms, carrying the potential of fighting illness from herpes to cancer.

There aren't any bees in the venom exhibit, but there is a tiny vial of honeybee venom on display and many of the strange and dangerous creatures that contribute to human health and comfort. Like the jararacussu, a snake from Central and South America.

When this snake, a relative of the deadly fer de lance, strikes a human being, the immediate result is a precipitous drop in the victim's blood pressure. These snakes invade coffee, banana and sugar plantations after the rats that this kind of farming encourages. In Costa Rica the jararacussu kills more people than any other snake. Its bite is not always fatal, but it is probably safe to say it has done in thousands of people over the centuries.

A new drug

In the mid-1970s, scientists began to examine the molecular and chemical structure of the venom of the jararacussu. They learned how the venom affected blood pressure, how the mechanism worked. This knowledge led to the development of a drug called Capoten, effective against heart disease and hypertension. It went on the market in 1981.

"It's used all over the world," said Cover. "It has saved millions of lives."

That's more than a fair exchange between humans and the snake in question, one would think.

Among the experimental drugs made from venom is Oxynor. Derived from the venom of the taipan -- a snake native to Australia and New Guinea -- this drug has potential in the treatment of burns, and as a diagnostic tool. "Something in this venom possibly would detect the presence of lupus," said Martha Regester, who's in charge of visitor education at the aquarium.

Nerve Growth Factor, another experimental drug, is drawn from the monocled cobra of Southeast Asia; it is thought to hold a substance that might help in the treatment of Parkinson's disease and Alzheimer's.

From the gila monster comes a venom that contains an element promising against diabetes. "Part of its venom mimics a human hormone involved in the production of insulin," said Regester.

To find what's good and useful in venom, scientists pull it apart. "Fractionate" is the term used for this. They examine every molecule, every atom, every enzyme, every chemical; they investigate how they all work together. It pays off.

Synthetics

The production of drugs from venom does not require a large amount of the stuff. When researchers find the chemical composition, or a reaction they believe effective, they reproduce it synthetically.

Hepoxin, taken from cobra venom, acts against herpes. Something in it is thought to inhibit the replication of the virus. Kaotree, from the Western diamondback rattlesnake and the cobra, is used in the treatment of cancer. HIVIP -- donated by the mightily venomous Australian taipan snake -- is also used against cancer.

A drug derived from the venom of the giant yellow Israelean scorpion inhibits certain kinds of cancer cells from migrating from one part of the brain to another.

Since these drugs are experimental, it's not always clear how they work. Regester speculates that the venoms that break down tissue and cells might be directed against cancer cells.

"That's their job," she said. "To attack tissue."

For those averse to creeping and slithering things -- especially if they're dangerous -- the aquarium's new show on venomous animals (it replaces the hugely successful exhibit on jellyfish) is an indulgence in shivery horror.

In addition to a variety of snakes, there is the black widow spider, the lionfish, the reef stonefish, the emperor scorpion, the Cameroon red tarantula, the cone snail.

This latter, which lives in and around the Great Barrier Reef of Australia, paralyzes its prey, usually fish and other mollusks, by delivering its venom through a kind of harpoon.

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