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Medicine men

For a thousand years, South American healers have enlisted a certain weed to cure coughs, colds, even tuberculosis. Now, a small group of researchers -- led by UC-Irvine Associate Prof. Edward Robinson Jr. '84 and TCU Chemistry Prof. Manfred Reinecke -- believe that something in wira wira may help defeat the virus that causes AIDS.

By Nancy Bartosek

IT TOOK a thousand lifetimes of knowledge to build the cramped biohazard level II lab at UC-Irvine, a sterile environment where blue antibacterial lights bathe stainless steel countertops and workers wear protective covers when entering the restricted space.

The small room, cluttered with plastic bottles and boxes and specialized equipment, is often unoccupied, the only sound a constant rush of air sucked through high-tech filters. But that doesn't mean nothing is going on.

In a red liquid incubating in a thick steel cabinet labeled BIOHAZARD, a microscopic war is being waged. It is a carefully contrived battle that may defeat a deadly killer. Dr. W. Edward Robinson Jr. '84, PhD, (above) heads the research team lining up the petri dish scrimmages between the virus that causes AIDS and a compound that stops the progression of the disease -- a substance they discovered. It is slow and tedious work performed by few on a limited budget.

If they unlock the secrets in the red solution, millions of people infected with HIV may live longer, healthier lives.

Like most scientific breakthroughs, the discovery has brought national attention to Robinson and company.

There is acclaim.

There is criticism.

And there is the youthful Robinson with the same smile and response to both: "It works."

EVERY DAY, Robinson and his assistants don green paper smocks and two pairs of surgical gloves before venturing through the inner door of Robinson's primate retrovirology lab. Working methodically at protective, glass-enclosed hoods, they mix fetal calf serum (which provides important nutrients and growth factors to the cells), active HIV cells and one of several compounds they are testing. When the mix is right, HIV infection is stopped.

The stuff of miracles? Perhaps. But to hear the scientists involved tell it, it's more a matter of creative thinking, a touch of serendipity and a heap of persistence. Robinson and TCU Chemistry Prof. Manfred Reinecke stumbled on the compound's hidden talent in 1989 when the former was studying the AIDS virus at Vanderbilt University.

Reinecke was on campus for a conference. Later, over dinner at a Nashville steak house, he told Robinson about some Bolivian plants he was breaking down chemically. Reinecke had been thinking to himself, Could Bolivian medicine men, practicing ancient healing arts for centuries, know something we don't? Now he was asking Robinson if he would test the compounds for medicinal uses.

"I wasn't expecting much, but I thought it would be interesting," Robinson said. "The bottom line was we got a very high hit rate. Eleven of the first 18 plants looked very promising as leads for anti-HIV activity."

Something in the compounds Reinecke sent worked against the virus without killing the host cells the HIV was infecting, something similar drugs weren't able to do. The next step: figure out what in the compound worked, and why.

Caffeic acid derivatives -- the active ingredients in Robinson's and Reinecke's successful compound -- are nothing new. They can be found in chicory bark, green coffee beans, and a gangly Andean mountain weed called wira wira. What wasn't known was that these minuscule molecules have a powerful effect on an enzyme called integrase, a necessary ingredient in the HIV infection process of immune cells. It took Robinson and Reinecke five years of testing, filtering, eliminating and retesting the rich, white powder extracted from various plants before they could say for certain what inhibited the growth of HIV. They didn't understand how, they only knew it did. And that was enough to keep them searching for answers.

IT'S HARD to imagine that one milligram of white dust (imagine the size of a pencil tip) could have much of an effect on anything. But in Robinson's lab, that powder packs a wallop.

Which is probably why the Bolivian medicine men, known by locals as "lords of the medicine bag," continue to grind up wira wira, the white powder's source, traversing from the valleys of the Amazon to the tops of Andean peaks, administering healing herbs since long before Western medicine and HMOs.

At least that's what Reinecke figured in 1988 as he listened to UT-Arlington ethnobotanist Joseph Bastien talk about his work with the Kallawaya Indians, an Andean mountain tribe that has farmed, gathered herbs and perfected their healing skills for 1,000 years. This small group of medicine men, today numbering about 350, even practiced successful brain surgery as early as 500 A.D., using only locally gathered medicines and handmade tools.

Reinecke's interest was piqued; he approached Bastien about acquiring some plants to test for biomedical purposes.

"Why not?" replied Bastien. Small grants from TCU and the Fort Worth Herb Society sent Bastien south and some plants north. "We were just a small-potatoes operation," Bastien recalls.

Several of the Bolivian plants -- including wira wira and carqueha -- showed strong antiviral activity from the beginning. But winnowing one pure compound from a plant containing hundreds, especially when the compound is unknown, is arduous at best. And expensive.

Initial results were promising enough for the National Institute of Health to give Robinson and Reinecke a three-year grant in 1991. Much of that time was spent finding out where the compounds didn't work.

"They didn't work at sites that all the other drugs worked at and that were easy to measure," Robinson said. "Trying to figure out how they worked was a tough thing. We knew they were antiviral but we didn't know how."

During that same time, Robinson was finishing his medical degree then moving to UC-Irvine to establish his own lab. A second NIH grant in 1997 kept them on the trail. The result? Eleven compounds in the dicaffeoyltartaric and dicaffeoylquinic acids group inhibited viral replication. L-chicoric acid, their lead compound (based on the chemical properties in the two acids that had the antiviral activity), was synthesized in Reinecke's lab.

"We now have a much better idea why the compounds work against the virus and why they work against the enzyme integrase," Robinson said. "The goal over the next several years is to look at the structure of the drugs, what their activity is and determine how to make better molecules. The hope is that within the next two or three years we'll have something that's potent and safe enough to test in animals, then people."

Robinson's compounds (which he, Reinecke, TCU and UC-Irvine are trying to patent) not only work, they work better, or synergistically, with existing anti-HIV drugs. Sort of a turbo-boost effect.

"It's like quadrupling the effect but only adding twice as much," Robinson said. Synergy is a critical plus when fighting living organisms. Consider, for example, man's lack of success obliterating tuberculosis or herpes.

"Nature finds ways to get around our attempts," Robinson said. "All we're doing is adding drugs to prevent a bacteria or virus. Kill off 99 percent of the bugs, and that one percent grows up as the predominant group and is now immune to the therapy." HIV is tough to treat because every time it replicates, it mutates. Design a drug for one strain and it changes and the drug no longer works.

Drug cocktails containing compounds that attack more than one stage of the disease can sometimes circumvent that. The idea is that if the virus mutates past one therapy, it probably won't around two, or three.

"It is clear there will never again be a single drug treatment for HIV," Robinson said. "Our drugs must work in the presence of existing anti-HIV agents because if they don't, they won't ever work. You cannot use a single drug for HIV therapy."

BAGS OF still-untested Bolivian plants lie patiently in Reinecke's storage room, waiting for their secrets to be released. With limited funding and personnel, the process continues at an academic pace.

"At some point this will have to be taken over by a pharmaceutical company that can put teams of people and money into the development of a usable drug," Reinecke said. Several companies have expressed interest but there haven't been any takers -- yet. "I think we're still on the edge, teetering," Robinson said. "Is it going to fall off the edge because we've got the best things we can ever get? Are we going to take the leap to the other side where it's in people? I don't know yet."

The likelihood of developing a new drug is very small. Robinson's work is still at stage one: developing a compound that works in tissue culture. Only about one percent of those drugs ever make it into people because many of them fall out at animal trial stage. If they do go into people, an equal number are too toxic or don't work well enough or the mutations come so fast you can't keep up.

"Those things are hurdles along the way," he said. "We're still working over the first hurdle now."

Robinson is more optimistic than that statement sounds. His tests have repeatedly proven effective, and each step has given them more reason to forge ahead. "We feel very confident that the drugs work," Robinson said. "We sent them out blinded and they were identified as functional. We have repeated the data 1,000 times under various permutations over the last five years.

"They always work."

So, forward they go. Reinecke, who for 34 years has encouraged and prodded TCU students who aspire to be doctors, says this work is the most exciting research of his career. "It's something significant."

The work isn't just a clinical exercise for Robinson, either.

"As corny as it sounds and perhaps as unreasonable as it is, I want to make an impact on the treatment or prevention of HIV," he said. "If I could come up with a drug that could be used in the Third World because it was cheap enough, or a drug that would lower side effects and improve life spans, it would have an impact on hundreds of thousands of people. I could never in my career as a physician have an impact on that many people. That's why I do this."

Robinson pauses, nods and smiles a knowing smile.

"So far we've had a lot of success. I think this is going to continue to progress."

The drug war

Tracking a killer The virus (A) must enter and join with the host cells' chromosome (B) for infection to take place. After infection, the diseased cell replicates (C), then sends the virus out (D) to infect still-healthy immune cells.

When a person is infected with the human immunodeficiency virus, they become a host to cells that infect immune cells in three distinct stages, each involving a separate enzyme. Each step must occur for the virus to live and reproduce itself.

Currently drugs are administered in the United States that generally stop or slow the first and the third interactions, which involve enzymes respectively called reverse transcriptase and protease. So far no one except UC-Irvine researcher Dr. W. Edward Robinson '84 has found a drug that will effectively stop the second stage of cell infection, which involves the enzyme integrase.

The compounds he and Chemistry Prof. Manfred Reinecke have isolated are effective integrase inhibitors that work in cell tissue without destroying the host cell. If research continues to progress positively, these compounds will be tested in animals within three or four years. In five to seven years there could be drugs available for human testing.

Contact Robinson at ewrobins@uci.edu or Reinecke at m.reinecke@tcu.edu.