• 4/9/2005
  • Lexington, KY
  • Jim Warren
  • Lexington Herald-Leader

Researchers at the University of Kentucky and Ohio State University are hoping that one of America’s favorite fruits also might prove to be a preventive for oral cancer.

They plan to test their theories in a trial at Ohio State this summer by using a purplish gel — made from freeze-dried black raspberries -to treat selected patients who have precancerous lesions in their mouths. Patients will apply the gel topically.

Once oral lesions become cancerous, disfiguring facial surgery may be the only treatment option. Tumors, however, often recur. Even when doctors surgically remove early, precancerous lesions, about half of them also recur with the potential of becoming life-threatening tumors.

But if the raspberry gel can prevent, or at least slow, the transformation of lesions into tumors, the medication could become an important new tool against oral cancer.

“Obviously we’d like to see these lesions completely disappear, but I think everyone would be happy just to see the whole process slowing down,” said Russell Mumper, an associate professor of pharmaceutical science at the University of Kentucky who is working on the project. “Ninety-nine percent or more of these lesions will advance to cancer.”

Oral cancers, which cause up to 8,000 deaths each year, generally are associated with alcohol and tobacco use, particularly when the two are combined. People who use both tobacco and alcohol face a 38-fold increase in risk, according to Ohio State. Until recently, most victims were men in their 60s or older. But cases have become more common in women as their tobacco and alcohol use increased over the past 30 years, and younger people now also are developing the disease. Because of that, doctors are scrambling for new treatments.

The idea for a medication made from raspberries was conceived by doctors at Ohio State’s Comprehensive Cancer Center in Columbus. They then turned to Mumper to actually develop the raspberry gel at UK’s Center for Pharmaceutical Science & Technology, an FDA-registered drug manufacturing and development facility. Mumper is the center’s associate director.

“We spent about six months developing various kinds of raspberry gels before we came up with the current version, which looks promising,” Mumper said.

While natural-food enthusiasts tout the nutritional and healthful benefits of raspberries, this apparently is one of the first efforts by mainstream medicine to develop a medication from the fruit. The pulp of black raspberries contains two substances — anthocyanin and ellagic acid — that are thought to have anti-oxidant and anti-inflammatory properties, as well as the ability to inhibit the tumor growth.

Ohio State researcher Gary Stoner, who has been studying the anti-cancer properties of raspberries for years, said his group determined that freeze-drying the raspberries and turning them into powder increased the concentration of cancer-preventive substances tenfold.

When Stoner and his colleagues fed the powder to test animals, it appeared to inhibit the development of esophageal and colon cancer as well as oral cancers. Researchers then determined that the raspberries’ anti-cancer substances would be better absorbed if applied directly to oral lesions, Stoner said. Based on that, they contacted Mumper about 18 months ago to start development of a topical gel made from the raspberry powder that patients could apply to their lesions. The gel is ready for testing.

In the trial, which will begin late this summer, Ohio State doctors will give the gel to 20 patients who have pre-cancerous oral lesions and to 10 healthy patients as a control. The patients will apply the gel four times per day for six weeks while researchers follow them closely for signs that the lesions’ growth is slowing. They also will be looking for any health risks associated with the gel.

If the drug works and the treatment ultimately receives FDA approval, patients probably would use the gel daily to slow or prevent oral cancers, Mumper said.

“When these kinds of lesions are identified, it scares the heck out of people,” Mumper said. “So the idea of being able to treat or even prevent the onset of cancer would be really significant.”