Fighting venom with a VIPER

Tuesday, 10 March 2009 00:00

Dr. Leslie Boyer holding a snake. Photo courtesy of Margaret
Hartshorn, senior photographer for Biomedical Communications
at The University of Arizona College of Medicine.

Venomous creatures lurk in Arizona and Mexico's deserts and an unfortunate encounter with the venom from a scorpion's stinger or a snake's bite on either side of the border can be fatal.

Fortunately, The University of Arizona's College of Medicine is home to the VIPER Institute, which stands for Venom Immunochemistry, Pharmacology and Emergency Response.

“They're [venomous creatures] just fundamentally cool. They bite us and we need to understand what's going on when that happens,” said Dr. Leslie Boyer, founding director of the VIPER Institute.

VIPER researchers study “venom injuries” through the genealogy, or family tree, of venomous creatures to develop treatments such as antivenoms, and also study the physiological effects of venom on the body, Boyer said.

When a person is stung by a scorpion, venom is absorbed into the bloodstream and travels to nerves throughout the body and causes muscles to twitch and jerk, Boyer said. She added that this can be fatal, particularly if it affects the lungs.

A snake's venom can also be fatal but operates differently. A rattlesnake's venom contains enzymes that act like “meat tenderizers,” breaking down the proteins of muscle fibers, Boyer said. The venom also triggers shock and causes the blood clotting mechanism to malfunction, she said.

In both cases, immediate medical treatment, typically through an antivenom, is crucial.

Currently the group is working with a firm in Mexico, Instituto Bioclon, to develop an antivenom for scorpion stings known in the United States as Anascorp and in Mexico as Clacramyn.

“The work that I'm doing probably could not be done by either country alone. What the United States has to offer with our difficult [Food and Drug Administration] is the standard of proof, to say a drug is effective is very high. So what we're doing in Arizona is establishing that the drug meets the standard in a way that was not done before it was brought here," Boyer said.

This project began in 1999 when Arizona State University in Tempe, Ariz. could no longer afford to develop antivenom for scorpion stings, Boyer said.

After learning that Arizona State University was no longer developing scorpion antivenom, in 1999, Boyer and some of her VIPER Institute colleagues traveled to the Insituto Bioclon where researchers were developing other antivenoms, she said.

In 2000, the VIPER Institute made a formal proposal to the Insituto Bioclon and soon after began their collaboration. Rather than reinvent a new antivenom, the VIPER Institute decided to continue the development of the Clacramyn or Anascorp antivenom that was formulated in Mexico, Boyer said.

This binational collaboration is partially funded through the Consejo Nacional de Ciencia y Tecnología (National Council of Science and Technology) or CONACYT, which is akin to the U.S. National Science Foundation, Boyer said.

The FDA has never approved an antivenom for scorpion stings even though there are roughly 250 scorpion sting cases in Arizona and 250,000 cases in Mexico each year, Boyer said.

VIPER also collaborates with Mexico's Instituto de Biotecnología, or the Institute of Biotechnology, in Cuernavaca, Morelos which is a part of La Universidad Nacional Autónoma De México.

Through this collaboration, biochemistry students from La Universidad Nacional Autónoma De México and pharmacy and medicine students from the UA exchange research and learn from one another's resources, she added.

“What we found is by doing the human part of the study north of the border and the laboratory part of the study in Mexico, we can look more thoroughly at the disease process,” Boyer said. “By doing all of that together, we're offering training opportunities for students that you couldn't get in either country and we are developing drugs in a better way than you could in either country.”

The institute is also developing a new rattlesnake antivenom because the effectiveness of the current antivenom in treating the blood clotting mechanism malfunction has been questioned, Boyer said.

"It's a very difficult one to study also because it's pretty rare and people show up here and there at different hospitals and at different times at night," she said.

In addition to developing antivenom, the institute is also researching the most cost-effective and efficient technique to deliver antivenom, both to hospitals and clinics as well as into the patient, she said. This involves studying the body's response to antivenom through various routes in the body, such as an intravenous route.

The institute consists of more than 125 national and international scientists and clinicians from all different fields, including pharmacy, radiology, and pathology, and includes the doctors who participate in the clinical studies that test the potential antivenoms.

Since the antivenom for scorpion stings, Anascorp, is currently unlicensed and awaiting approval from the FDA, it is required that it be used as an experimental drug. There are currently 22 Arizona hospitals participating in clinical studies of the antivenom.

The group began as an informal partner to the Arizona Poison Center in 2004 and in 2007 was granted institute status by the Arizona Board of Regents. It is funded through state and federal grants, including grants from the FDA and the companies that produce the antivenoms.

These venomous encounters are difficult to study and record because they are rare and occur all over the world, Boyer said.

However, the medical developments from the institute's research illustrates the need to continue studying these dangerous creatures.

“They know tricks that we don't and learning how they make certain chemicals and what the chemicals are for can allow us to make new medications for diabetes, for blood pressure control, for strokes, for all kinds of things where the chemicals in the venom itself can either be used or modified to serve human good,” Boyer said.

Written by Megan Levardo