The inhibitory effect of proanthocyanidin on soluble and collagen-bound proteases

Don Jeevanie Epasinghe, Cynthia Kar Yung Yiu, Michael Francis Burrow, Noriko Hiraishi, Franklin Russell Tay

Research output: Contribution to journalArticlepeer-review

65 Scopus citations


Objective This study evaluated the inhibitory effect of proanthocyanidin (PA), a natural collagen cross-linker, on soluble and matrix-bound proteases, which are responsible for progressive degradation of exposed collagen fibrils within the hybrid layer and resin-dentine bond failure over time. Methods The inhibitory effects of PA (1%, 2%, 3%, 4.5% and 6%) on soluble recombinant matrix metalloproteinases (MMP-2, -8 and -9) and cysteine cathepsins (cathepsin B and K) were evaluated using MMP and cysteine cathepsins fluorometric assay kits. Chlorhexidine (CHX) was used as an inhibitor control. The effect of PA on endogenous matrix-bound proteases was examined by determining the change in dry mass of demineralized dentine beams and solubilized collagen peptides over 30 days. Two-way ANOVA and Tukey multiple comparison tests were used to analyze the effect of PA and proteases on the percentage inhibition of soluble proteases (α = 0.05). Kruskal-Wallis one-way ANOVA and Dunn's multiple comparison tests were used to analyse the effect of PA on loss of dry mass and hydroxyproline content over time (α = 0.05). Results Proanthocyanidin inactivated more than 90% of soluble recombinant MMP-2, -8 and -9 and around 75-90% of cysteine cathepsin B and K, which was significantly higher than CHX (P < 0.05). The inhibition of endogenous proteases by PA increased in a dose-dependent manner. The loss of dry mass and hydroxyproline release in the medium over time was the lowest in dentine beams pretreated with PA < CHX < control (P < 0.05). Conclusion Proanthocyanidin exhibited both dentine MMP and cysteine cathepsins inhibition, which was higher than chlorhexidine.

Original languageEnglish (US)
Pages (from-to)832-839
Number of pages8
JournalJournal of Dentistry
Issue number9
StatePublished - Sep 2013


  • Collagen cross-linking
  • Cystein cathepsins
  • Dentine
  • Matrix metalloproteinases
  • Proanthocyanidin

ASJC Scopus subject areas

  • Dentistry(all)


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