Effect of Propargylglycine on the Viability of Human Oral Cells

Objectives: Methionine gamma-lyase 2-aminobutyrate deaminase (mgld) is one of the chief enzymes of methionine metabolism in P. gingivalis. Methionine is catabolized by mgld into methanethiol, ammonia and α-ketobutyrate. Methanethiol causes halitosis and is purported to lead to periodontitis. The inhibition of mgld by propargyglycine (PG) in vitro has been shown previously. The objective of this study was to assess the possible cytotoxic effects of PG on human oral cells/lines.
Methods: Oral squamous epithelial cells (TR-146; ATCC, Manassas, VA) and human periodontal ligament cells (PDL; Sciencell, Carlsbad, CA) were obtained and cultured under standard conditions. Cells at 10,000/well were treated with increasing concentrations (1, 5, 10, 25, 50 and 100 µM) of PG and the cell viability was assessed using a standard colorimetric MTT assay and a live dead cell assay.
Results: Cell viability data (mean± SD, n=6) for treated cells (+PG) compared to control (-PG) is shown in the table below. Cell viability of +PG group did not change at any concentrations compared to –PG group. Interestingly however, there was slight increase of growth seen with PDL cells compared to squamous epithelial cells. The results were confirmed by the live dead cell assay.
Conclusions: PG is nontoxic to cells, therefore PG has a great potential as a mouthwash ingredient to improve oral hygiene.