Secrets of the hive
Propolis might have life-saving properties
By Sara Specht
From eNews, March 20, 2008
Marla Spivak harvests propolis from her hives on the U's Twin Cities campus, as well as from contacts around the world. And it all began with a sore throat.
Unexplained disappearances, a baffling plague, and an irreplaceable society crumbling: these are not the trappings of a musty history textbook or war coverage from across an ocean. They are essential pieces of a modern-day mystery that spans the globe.
This is the story of honeybees, their struggle to survive and the secret they may have to saving themselves. It's the tale of three CFANS investigators and their team, who hope to learn the bees' secret and use it to save humans, as well.
About seven years ago, a researcher from the Ukraine working at the University of Minnesota Medical School on lab trials to combat HIV came down with a cold. She, like countless people around the world, had always relied on a traditional treatment for such woes, a substance found in any honeybee hive: propolis.
Propolis, sometimes known as bee glue, is a thick, sticky resin that bees collect from tree buds and use to cement holes in the hive and defend it against invading parasites and diseases. Traditional healers from South America, China, Japan, and Eastern Europe have valued propolis as a remedy for such ailments as gum problems and dental health, skin issues and oral sores, as well as viruses and the common cold.
The researcher tracked down propolis at the Minneapolis farmers' market and made herself a tincture to soothe her viral woes. Then she brought her cure to work with her and ran a test: propolis versus HIV. Propolis won.
Propolis demonstrated antiviral activity against HIV, prompting a study on propolis that paired the Medical School with a team of researchers from CFANS. Results were promising, but propolis is an incredibly complex substance, and the mystery of precisely which elements are active remained. The study's implications were intriguing, however.
Where the bees are
"I started thinking, 'Wait, if propolis is so good for humans, it's got to also be good for bees,'" explains bee expert Marla Spivak, co-principal investigator in a new two-year project to identify the active compounds in honeybee propolis.
For the past several decades, bees have been stricken by parasites and viruses introduced by humans and global movement, to the point that wild or feral honeybees have become virtually extinct, says Spivak, a professor in the Department of Entomology. In the past year, entire colonies have mysteriously disappeared in an epidemic bee experts have named Colony Collapse Disorder (CCD), which has decimated some beekeepers' bee populations.
Spivak speculates that CCD could be the cumulative effect of diseases and parasites that affect only honeybees, new systemic insecticides, crop specialization, and destruction of native plant corridors, among other things. Whatever the cause, CCD threatens the pollinators of one-third of all U.S. food crops.
Spivak reasoned that a study could address both honeybee and human health. Testing chemical compounds against bee diseases can be done much faster than studies with human subjects, and results could quickly be applied to combat bee diseases or to test compounds against HIV and other human viruses. She enlisted two colleagues from the University's original propolis study-- Jerry Cohen and Gary Gardner, both from the Department of Horticultural Science--to join her on the project, which is funded by a grant from CFANS.
"I went to Jerry and said, 'What would be really cool would be to analyze the components of propolis and to use the bee as a screen to quickly test which are active against bee diseases and bee viruses'," Spivak explains. "So I came up with the idea to use the bees as a screen, and they came up with the methods."
"One of the limitations of the original project we worked with was that we had no rapid assay for biological activity," Cohen says. "It involved harvesting cells from patients, so it wasn't trivial. What makes the bee part of this project very important is the quick screening system for bacteria that cause the death of bees."
Propolis fresh from the hive.
Using propolis supplied by Spivak's contacts from countries around the world, as well as from her own hives on the Twin Cities campus in St. Paul, the study will identify any variations that arise from different plant sources in propolis from different locations, as well as any role the bees may have in altering its chemistry. The three professors collaborate with Lana Barkawi, a postdoctoral biochemist in Cohen's lab, and toxicology graduate student researcher Mike Wilson to create their new screening process.
The ultimate goal of the rapid assay will be to identify any new compounds that show anti-microbial activity toward bacteria and viruses that infect insects. Then the researchers will submit those compounds to an external service to test their activity against enzymes unique to the HIV virus.
"The danger with something like propolis, because it's been looked at for literally millennia, is that you can move down the line and discover something that's already known," says Gardner. "Our focus is on two key terms: active and novel."
"We might find something novel that's never been evaluated on HIV, we might not," Gardner says. "But we have this background in propolis and HIV expression, so it's not like we're saying we can cure AIDS because propolis is good."
A long-term hope, says Spivak, "is that after testing propolis components on bee diseases and viruses, we can find components that would be really helpful to treat human viruses, and particularly an inexpensive treatment for HIV for developing nations."
"I really hope that bees change propolis when they collect it, because that leaves bees in the picture," she says. "I want them to be indispensable, so that people maintain the bees, which are so important."
Edited from Solutions, a publication by the College of Agricultural, Food and Natural Resource Sciences.