Inhibition of periodontopathogen-derived proteolytic enzymes by a high-molecular-weight fraction isolated from cranberry

Background: Porphyromonas gingivalis, Tannerella forsythia and Treponema denticola are three major aetiological agents of chronic periodontitis. The strong proteolytic activities of these bacteria are critical to their survival since their energy source is obtained from peptides and amino acids derived from proteins. In addition, proteases are important factors contributing to periodontal tissue destruction by a variety of mechanisms, including direct tissue degradation and modulation of host inflammatory responses. Objectives: The aim of this study was to investigate the effect of non-dialysable material (NDM) prepared from cranberry juice concentrate on the proteolytic activities of P. gingivalis, T. forsythia and T. denticola. Methods: The effect of NDM on gingipain and dipeptidyl peptidase IV (DPP IV) activities of P. gingivalis, trypsin-like activity of T. forsythia and chymotrypsin-like activity of T. denticola was evaluated using synthetic chromogenic peptides. In addition, the capacity of P. gingivalis to degrade fluorescein-labelled type I collagen and fluorescein-labelled transferrin in the presence of NDM was evaluated by fluorometry. Results: NDM dose-dependently inhibited the proteinases of P. gingivalis, T. forsythia and T. denticola as well as type I collagen and transferrin degradation by P. gingivalis. Conclusions: These results suggest that NDM has the potential to reduce either the proliferation of P. gingivalis, T. forsythia and T. denticola in periodontal pockets or their proteinase-mediated destructive process occurring in periodontitis.