Natural compound in bananas could hold key to stopping HIV

Sunday, March 21, 2010 by: Sherry Baker, Health Sciences Editor
Tags: bananas, HIV, health news

(NewsTarget) University of Michigan (U-M) Medical School scientists have found a potent substance that could block the sexual transmission of HIV, the virus believed to cause AIDS. This HIV preventative isn't a potent new drug or chemical-laden vaccine. Instead, it's a natural substance derived from a popular, inexpensive fruit -- bananas.

In their study, just published in the Journal of Biological Chemistry, the researchers noted that HIV/AIDS remains a world-wide epidemic. "HIV is still rampant in the U.S. and the explosion in poorer countries continues to be a bad problem because of tremendous human suffering and the cost of treating it," study senior author David Marvovitz, M.D., professor of internal medicine at the U-M Medical School, said in a statement to media.

Bottom line: new ways of stopping the spread of HIV are desperately needed. In fact, the rate of new HIV infections is currently outpacing the rate of new patients receiving Big Pharma's expensive anti-retroviral drugs by 2.5 to 1. And while the medical establishment has pushed the idea of an AIDS vaccine for decades, an effective vaccine remains elusive. However, lectins, which are naturally occurring chemicals in plants, could hold the key to fighting HIV/AIDS because they are able to stop the chain of reactions that lead to a variety of infections, including HIV.

The U-M scientists specifically studied BanLec, the lectin found in bananas. In laboratory tests, they found it was just as potent as two current anti-HIV drugs. In a statement to the media, the researchers said BanLec may become a less expensive new component of applied vaginal microbicides (topical treatments used to stop the spread of HIV through sexual contact).

Although condom use can be effective in preventing HIV from being transmitted, condoms are successful only if used consistently and correctly -- but that's not often the case. "That's particularly true in developing countries where women have little control over sexual encounters so development of a long-lasting, self-applied microbicide is very attractive," Dr. Marvovitz explained.

The new study found that lectins, sugar-binding proteins, are able to "outsmart" viruses. They identify a virus in the body and attach themselves to it. BanLec was found to inhibit HIV infection by binding to the sugar-rich HIV-1 envelope protein dubbed gp120. The result? The virus was blocked from replicating.

Study co-authors Erwin J. Goldstein, Ph.D., professor emeritus of biological chemistry at U-M and Harry C. Winter, Ph.D., research assistant professor in biological chemistry at U-M, invented the biopurification method used to isolate BanLec from bananas. They pointed out that although they found that the banana-derived HIV inhibitor was similar in potency to T-20 and maraviroc, two anti-HIV drugs currently in clinical use, there are some big differences.

First, therapies incorporating BanLec should be cheaper than current anti-retroviral prescription medications made from chemicals. What's more, the researchers stated that BanLec could provide a wider range of protection from HIV than synthetically created drugs do.

"The problem with some HIV drugs is that the virus can mutate and become resistant, but that's much harder to do in the presence of lectins," lead author Michael D. Swanson, a doctoral student in the graduate program in immunology at U-M, noted in a press statement. "Lectins can bind to the sugars found on different spots of the HIV-1 envelope, and presumably it will take multiple mutations for the virus to get around them."

The scientists stated that even if the banana-derived HIV preventative is only modestly successful, it could save millions of lives. Other studies have previously estimated that 20 percent coverage with a microbicide that is even 60 percent effective against HIV may prevent up to 2.5 million HIV infections in three years.

For more information:
http://www.jbc.org/content/285/12/8646.abstr...

About the author

Sherry Baker is a widely published writer whose work has appeared in Newsweek, Health, the Atlanta Journal and Constitution, Yoga Journal, Optometry, Atlanta, Arthritis Today, Natural Healing Newsletter, OMNI, UCLA's "Healthy Years" newsletter, Mount Sinai School of Medicine's "Focus on Health Aging" newsletter, the Cleveland Clinic's "Men's Health Advisor" newsletter and many others.