Episode Transcript
Interviewer: Traditional medicines that interfere with life saving AIDS treatments, up next on The Scope.
Announcer: Examining the latest research and telling you about the latest breakthroughs. The Science and Research Show is on The Scope.
Interviewer: For the 35 million people worldwide who are living with AIDS, antiretroviral therapies are life saving medicines that can slow or halt the disease. But in some non-western countries, cultures can impact the effectiveness of treatment.
I'm talking with Dr. Lou Barrows, professor of pharmacology and toxicology at the University of Utah. He's investigating interactions between traditional medicines and antiretroviral therapies in Papua New Guinea. Dr. Barrows, how much of a problem is AIDS in Papua New Guinea? Why did you focus on that problem?
Dr. Barrows: Well, Papua New Guinea is an interesting case, it has, it's the only country in the South Pacific with and established HIV epidemic, but it's fairly low level. It's less than 1% nationwide, but in some villages the incidents of HIV is around 10%, and so it's of great concern that it still might spread.
Interviewer: So maybe you can talk a little about traditional medicines in Papua New Guinea, and how much that is a part of their lifestyle there.
Dr. Barrows: It's generally accepted that Papua New Guinea is like many of the developing countries in the world where about 80%of the people use medicinal plants for health purposes, and it's certainly part of the culture. And so we had some, quite a bit of background data on commonly used medicinal plants in Papua New Guinea, and some understanding that a lot of people use them a lot. And that when people are being treated with western medicine they go home and they also take their vitamins, their nutritional supplements or their herbal medicines, whatever you want to call it.
So, it's clear that there is potential for these things to interact, and there is lots of data from western medicine showing interactions of dietary supplements and medicines. So it was a logical question to ask.
Interviewer: And so what did you find?
Dr. Barrows: The approach we took, basically some in vitro assays looking at the ability of one drug to interfere with the activity of another, either by interfering with its metabolism, interfering with your body's ability to get rid of it, or by inducing enzymes that allow your body to get rid of things faster. And so, obviously if your drinking grapefruit juice and it inhibits liver cytochrome P450 3A4, then drugs that are metabolized by 3A4 are going to be at higher levels in your body and they might actually reach toxic concentrations, and this has happened.
That's the same system, identical system we use. But instead of things you might find at our grocery store, we use, we had our list of the hundred most used medicinal plants in Papua New Guinea from the database and so we went and collected them and looked at their ability to interfere with drug metabolism.
Interviewer: So when you see this enzyme, the cytochrome, when you see it go up, the activity go up.
Dr. Barrows: So if the enzyme goes up, then it's more effective at clearing the drug from your body. So then the drug might not reach effective levels and this has also been shown to happen.
Interviewer: So you found that some extracts from some traditional medicines actually raised the levels of the cytochrome and some lowered them. Are you talking about big effects or is it enough to suggest that it might, in some cases, totally inhibit the effects of the antiretroviral therapy or can you make those sorts of conclusions?
Dr. Barrows: I think we can because there's enough experience in drug development in western countries with big pharma and my colleagues here have actually been working in that capacity. So they have the same standards for what's considered a predictor of a clinically relevant effect.
Interviewer: What do you intend to do with the information you have now?
Dr. Barrows: I'm actually also an adjunct professor at the University of Papua New Guinea. So my colleagues at UPNG are quite interested at making sure this information gets back to the national AIDS council, well it actually already has. And they and the national AIDS council are now keen at putting together basically a little pamphlet that will go around to the AIDS clinics just identifying the different plants in the local languages. Papua New Guinea is an interesting place because there's supposedly over 800 different language groups, it's very diverse.
Interviewer: Barrier number one.
Dr. Barrows: Right, so it'll be a long pamphlet. Basically some of the most, what we think are the most problematic ones, the patients coming in for their antiretroviral therapy can be counseled to avoid consumption of this while you're taking these drugs.
Interviewer: What are the chances of that working? I mean, you're going against hundreds of years of culture, right?
Dr. Barrows: You know, its funny, I'm sure there will be a whole spectrum depending on the person and the village and how much they believe, how much they believe or they don't believe the health care workers or whatever. Most of the people I've met out in the bush, they're all pretty independent thinkers and if they understand the issue, then they're going to the make the logical decision. And if they understand that you take this at the same time you're taking this, this won't work, then they'll follow it.
Interviewer: Does your research have any implications for us here in the United States?
Dr. Barrows: So, one issue for us here in the U.S. is that while these plants are commonly used in Papua New Guinea, they are not kind of the golden seal or the cranberry juice or the Echinacea that are the major products in the U.S. But there is kind of a shift in these dietary supplements available in the U.S. and that's because of this global access to everything over the internet.
You can now buy many of these plants that we thought were Papua New Guinea traditional medicines, you can buy them over the internet for all sorts of purported uses, whether they are active or not I don't know, but some of them are pretty active at effecting drug metabolisms.
Announcer: Interesting, informative, and all in the name of better health. This is the Scope Health Sciences radio.