Arginine Dentifrice Reduces Secretion of Matrix Metalloproteinases by Monocytic Cells

Objectives: Monocytes becomes activated by bacterial lipopolysaccharide (LPS), and tend to secrete excessive pro-inflammatory cytokines and matrix metalloproteinases (MMPs). In order to reduce the over expression of destructive cytokines mediated by bacterial LPS, additives were introduced into various oral products. The Objective of this project is to test the effect of arginine (Arg) dentifrice on the secretion of matrix metalloproteinaces (MMPs) by cultured monocytic cells.
Methods: THP-1 (ATCC TIB 202) was cultured and were differentiated to monocytes by incubating with 200 nM of PMA. A 1% (W/V) suspensions of commercial tooth pastes, Colgate Sensitive Pro-relief ^® (CSPR), Tom’s of Maine Rapid relief Sensitive ^® (TRRS), both contain Arg, and Colgate Cavity protection ^® (CCP) and Crest ^® Pro-health (CPH) in PBS and filter sterilized. Differentiated monocytes (1x10⁵ cells/ml) were incubated for 24 h with lipolysaccharide (LPS) of Porphyromonas gingivalis (10 ng/ml) in the presence of 0.2 ml of each dentifrice suspension or PBS (control) for 24 h. Culture supernatants were collected and assayed for secreted MMP-2 and MMP-13 by ELISA (R & D Labs). All assays were done using quadruplicate samples and repeated three times.
Results: Monocytic cells ability to secrete the MMPs was inhibited significantly (P < 0.05) by the Arg-dentifrice. In the presence of CCP or CPH the cells secreted about 600 pg/ml of MMPs. When the cells were incubated with CSPR or TRRS, the cells secreted approximately 54% less MMPs.
Conclusions: Dentifrices with Arg appears to play an important role in suppressing the secretion of inflammatory MMPs, thus minimizing the inflammatory conditions associated with periodontal disease in response to LPS of periodontal pathogens.