Histatin Levels in Salivary Secretions of Periodontitis Patients

Histatins comprise a family of proteins present in human salivary secretions. Indirect antimicrobial activity of histatin 5 has been demonstrated by its inhibitory effect on bacterial derived enzymes such as gingipains, produced by P. gingivalis, and by the neutralizing effect on bacterial toxins such as leukotoxin. Histatins also inhibit host derived enzymes such as MMP-9 and MMP-2, implicated in periodontal disease. The inhibitory activity of histatins against bacterial and host derived proteases involved in periodontal destruction suggests an important biological function for histatins in the development and treatment of periodontal disease. Objective: The purpose of this study is to quantify total salivary protein levels and histatin levels in a group of healthy patients and in a group of periodontitis patients. Method: Whole saliva and parotid saliva were collected from periodontitis and periodontally healthy subjects. The total protein level of the collected samples were determined by BCA method. Salivary samples were subjected to electrophoretic analysis using the cationic PAGE system. Histatin levels were determined by densitometric analysis. Results: Total protein levels in whole and parotid saliva were determined to be significantly higher in periodontitis patients than in periodontally healthy subjects. In parotid saliva samples, histatins were elevated in periodontitis patients relative to control subjects. With this methodology, histatins were detected at significantly higher levels in parotid saliva than in whole saliva within each subject. Conclusions: This data indicate that salivary glands may respond to inflammatory disease in the oral cavity by boosting the innate host defense system. Diseases, such as periodontitis, increase the production of histatins as well as several other salivary proteins. Supported by Healthy Professions Division Research Grant and in part by NIH NIDCR Grants DE07652 and DE05672 to FGO.