Characterization of plant polyphenols with dentin matrix activity

Extracts of the polyphenol-rich plants, Vitis vinifera L. and Theobroma cacao L., exhibit a selective effect on the dentin collagen matrix of teeth by increasing of its stiffness and inhibiting its degradation by collagenase. This effect is of great value in terms of developing novel dental preventive and reparative therapies. Interestingly, the extract of another polyphenol-rich plant, Euterpe precatoria Mart. (Açaí), only inhibits collagenase activity, while not affecting dentin stiffness significantly. In order to map the active phytoconstituents underlying this activity, initial steps were performed to characterize both the extract and the primary active fractions. A new fractionation method was established based on vacuum liquid chromatography using Sephadex LH-20, with follow-up by TLC, HPLC and LC-MS. Biochromatograms were established and revealed that the relevant dentin matrix activity is concentrated in few fractions, which were shown to contain medium- to high-oligomeric proanthocyanidins. Further high-resolution preparative separation of these active fractions and characterization of the relatively high MW active components is under way.