Saliva and oxidative stress in oral cavity and in some systemic disorders.

Saliva is a liquid environment of the oral ecosystem that to some extent reflects the local state of oral cavity or the general state of health of the human body. Since saliva reflects general health status of the human organism and is easy to collect, it can be used as a non-invasive diagnostic tool. In the present review the authors discuss and highlight the role of oxidant-antioxidant balance in the blood and saliva in human pathology. Particularly, the evaluation of oxidative stress status was proposed as an important factor in diagnosing the development and progress of such general diseases as periodontal disease, oral cancer, diabetes, rheumatoid arthritis, chronic renal failure, obstructive sleep apnea syndrome, and HIV. Moreover, the tryptophan metabolites via kynurenine pathway measured in the plasma and saliva are proposed as new and sensitive markers of oxidative stress status. It is concluded that measurement of oxidative stress in salivary fluid may provide a tool for diagnosing, monitoring and treatment of some systemic diseases as well as of local pathologic disturbances (e.g. periodontal disease).