Oral biologists at the State University of New York at Buffalo have developed a saliva-derived peptide that may be able to treat candidiasis and other fungal conditions in people undergoing chemotherapy or organ transplantation or those infected with HIV.
In a March 10 presentation at the International Association for Dental Research meeting in Honolulu, Dr. Libuse Bobek, Ph.D., professor of oral biology in the University at Buffalo School of Dental Medicine and senior investigator, presented research findings.
"We wanted to develop an antifungal agent that would have fewer side effects than current treatments," she said. "We found that a peptide called MUC7 12-mer-D—a small piece of the parent human salivary protein mucin—killed 95 percent of the fungal agent Candidiasis albicans in saliva in vitro."
Peptides are susceptible to enzyme degradation in saliva, which makes them less active or completely inactive, but this is not the case with MUC7 12-mer-D, Dr. Bobek noted. "This peptide, in which D-amino acid derivatives are substituted for natural L-amino acids, is not recognized and thus is not broken down by protein-degrading enzymes in saliva," she said.
Dr. Bobek and her colleague Dr. Guo-Xian Wei tested the activity of the D peptide in saliva and salt solutions containing C. albicans. They also compared its fungicidal activity with MUC 12-mer, the natural L form of the peptide, which is active against C. albicans but is susceptible to enzyme degradation.
They found that in saliva at a high concentration, the D peptide killed 95 percent of C. albicans, while the L peptide killed only 56 percent. At much lower concentration, the D peptide killed 85 percent of the fungal agent, while the L form killed less than 20 percent. The D peptide also was much less toxic than current treatments.
Researchers plan to test the antifungal activity of MUC7 12-mer-D in a mouse model of oral candidiasis.
