Saliva Contains Wound Salve

Why do animals lick their wounds? And why do wounds inside the mouth get better faster than comparable wounds on the skin? In rodents, these healing effects have been traced to epidermal and nerve growth factors in saliva. But human saliva contains only minimal amounts of these compounds, so Menno J. Oudhoff of the University of Amsterdam and colleagues knew that they would have to look further for the full answers (FASEB J., DOI: 10.1096/fj.08-112003). The researchers grew layers of human inner-cheek cells in dishes and scratched the layers to create artificial wounds. They then fractionated human saliva by HPLC and tested each fraction’s ability to speed healing of the wounds. The Dutch team found that the fraction that enhanced healing of the cell layers contained histatins. Until now, these peptides were known only for protecting the mouth against microbes. The authors note that histatins are relatively stable and aren’t hard to produce, making them “attractive candidates for development as therapeutics for promoting wound healing.” For example, histatins could be useful for treating patients whose wounds heal poorly, such as diabetics and burn victims.