Antimicrobial Peptides in Saliva and Salivary Glands: Their Roles in the Oral Defense System

Abstract

The majority of inflammatory diseases in the oral cavity arise from infections caused by several oral microorganisms inhabiting the biofilms formed on the surfaces of teeth, prosthetic devices, and oral mucosa. Human whole saliva is a mixture of secreted saliva from major and minor salivary glands. In addition, it also contains components derived from crevicular fluid. A number of families of peptides, such as cystatins, histatins, statherins, lipocalins (VEG protein), chromogranins, calprotectins and defensins, are found in whole saliva. In recent years, much attention has been focused on these peptides because they show antimicrobial activity against oral pathogens. These naturally occurring antimicrobial peptides are anticipated to be potent therapeutic agents for oral infectious diseases because the acquision of microbial resitance to antibiotics is one of the most serious problems for antibiotic therapy. The present paper reviews recent findings of studies on antimicrobial peptides found in saliva and salivary glands, with special reference to their nature and function in maintaining oral health. We further discuss the methodology in basic research on antimicrobial peptides as well as the possibility of their clinical use in oral health care science.