New research suggests that the polyphenols in green tea may inhibit the formation of osteoclast cells in alveloar bone. The study, which was published in the October issue of the Journal of Periodontal Research, looked at the effect of green tea phenols on osteoblast cells in the presence of Porphyromonas gingivalis.

Alveolar bone resorption and subsequent loss of mineral and organic constituents of the bone matrix, is caused by either multinucleated osteoclast cells or matrix metalloproteinases (MMPs). Porphyromonas gingivalis has been reported to stimulate the activity and expression of several groups of MMPs, whereas (-)-epigallocatechin gallate (EGCG), the main constituent of green tea polyphenols, has been reported to have inhibitory effects on the activity and expression of MMPs.

In this study,the researchers investigated the effects of the green tea polyphenol, EGCG, on the gene expression of osteoblast-derived MMPs, stimulated by P.gingivalis, and on the formation of osteoclasts in the bone cells of mice.

P.gingivalis extracts stimulated the expression of MMPs which was significantly reduced by EGCG. In addition, EGCG also significantly inhibited osteoclast formation.

The reserchers concluded that these findings suggest that EGCG may prevent the alveolar bone resorption. that occurs in periodontal diseases by inhibiting the expression of MMPs in osteoblasts and the formation of osteoclasts.

Journal of Periodontal Research; Volume 39, Issue 5, Page 300 Oct 2004