The effect of oxygen-derived free radicals on gingival proteoglycans and hyaluronic acid

The effect of a chemically induced oxygen‐derived free radical flux has been studied on extracted porcine gingival hyaluronic acid and proteoglycans as well as on cryostat sections of porcine gingivae. The result of the free radical producing system on hyaluronic acid and the proteoglycans was one of reduction of specific viscosity and molecular size. When frozen sections were subjected to the same oxygen‐derived free radical flux and subsequently stained with Alcian blue, a noticeable decrease in staining intensity was observed when compared to control sections. These results are considered to reflect the in vitro capacity of oxygen‐derived free radicals to depolymerize the two major non‐fibrous extracellular macromolecules of gingivae. It is postulated that such a mechanism may be responsible, at least in part, for the destruction of gingival proteoglycans and hyaluronic acid observed in inflammatory periodontal disease.