ANN ARBOR, Mich., Jan. 11 (UPI) -- The naturally occurring preservative nisin was found to kill cancer cells and antibiotic-resistant bacteria in mice, according to a new study conducted at the University of Michigan.
In the experiments, researchers found the preservative stopped or slowed the growth of squamous cell head and neck cancer. Nisin already is known to alter bacterial cells, rendering them harmless, which the scientists said is why they have been looking into its effects on cancer cells.
Nisin is a natural preservative that grows on dairy products, and has been approved for several years by the U.S. Food and Drug Administration, so it is already known to be safe for human consumption.
Dr. Yvonne Kapila, a professor in the school of dentistry at the University of Michigan, has been working with nisin's effects on cancer and other infections for several years. In 2012, she reported the potential effect the preservative has on cancer -- which has now been pushed forward with her new research.
"The application of nisin has advanced beyond its role as a food biopreservative," Kapila said of the new study, in a press release. "Current findings and other published data support nisin's potential use to treat antibiotic resistant infections, periodontal disease and cancer."
In the new study, published in the Journal of Antimicrobial Chemotherapy, Kapila found an 800 milligram dose of nisin given to rats for nine weeks reduced the size the rodent's tumors by 70 to 80 percent.
Kapila also has conducted experiments with nisin on 30 different types of cancer, and infections on the skin, respiratory system, and abdomen, and on oral health.
Although nisin already is available in creams and pharmaceuticals to fight infections and mastitis, Kapila said there is no way to know if its effects on cancer in rats will translate to humans, which she said is the next step for future research. Based on previous experiments, and what Kapila said amounts to nature, she has high hopes.
"To date, nobody had found bacteria from humans or living animals that is resistant to nisin," Kapila said. "Mother Nature has done a lot of the research for us -- it's been tested for thousands of years."