A small piece of protein from the end of a human saliva molecule can kill several types of bacteria and fungi, said researchers at the International Association for Dental Research’s 80th General Session and Exhibition in March.
The protein segment, a peptide called MUC7 20-mer, has been shown in in vitro studies to kill fungal agents that cause common opportunistic infections. These infections affect immunocompromised patients, patients who received organ transplants and patients undergoing chemotherapy. The peptide also kills bacteria such as Escherichia coli, Porphyromonas gingivalis and Streptococcus mutans.
Researchers said the peptide causes changes in fungal cell membrane electric potential, is internalized into the cells and may act on a specific part of the subcellular machinery. MUC7 20-mer is active in vitro at very low concentrations and shows no toxicity to mammalian cells and little tendency to elicit drug resistance.
People still have oral infections, despite the potent antimicrobial potential, because the peptide rarely is present by itself and the large protein molecule from which it is derived does not have microbial activity.
If the in vitro laboratory test findings are confirmed in animal and human trials, the peptide could form the basis for new drugs used to treat a wide range of infections, said Libuse Bobek, Ph.D., associate professor of oral biology at the State University of New York at Buffalo School of Dental Medicine.
"We think this naturally occurring agent has high therapeutic potential for treating microbial infections in general and drug-resistant fungal strains in particular," said Dr. Bobek. "It also has potential as a component of artificial saliva for treating salivary dysfunctions that result in increased plaque formation, cavities, gum disease and fungal infections."
