Potential Use of L-Arginine Amino Acids towards Proliferation and Migratory Speed Rate of Human Dental Pulp Stem Cells (hDPSCs).

OBJECTIVE: Inflamed pulp has a decreased amount of protein and amino acids. L-Arginine is a semi-essential amino acid, the production of which is insufficient under oxidative stress and inflammation. L-Arginine is the sole substrate for nitric oxide synthase (NOS) to produce nitric oxide (NO), which plays an important role in cell proliferation and migration. This study aims to evaluate the proliferation and migration rate of hDPSCs after L-Arginine supplementation.

METHODS: Serum-starved hDPSCs were divided into four groups: control: hDPSCs in Dulbecco's modified Eagle medium; hDPSCs in 300 μmol/L of the L-Arginine based culture media group; hDPSCs in 400 μmol/L of the L-Arginine based culture media group; and hDPSCs in 500 μmol/L of the L-Arginine based culture media group, which were planted in two separate 24-well-plates (5x104 cell/well) for proliferation and migration evaluation. The proliferation of all groups was measured by using a cell count test (haemacytometer and manual checker) after 24 h. The migratory speed rate of all groups was measured by using cell migration assay (scratch wound assay) after 24 h. Cell characteristics were evaluated under microscope (Inverted microscope, Zeiss®, Observer Z1, UK) that can be read through image-J® interpretation. This image J represented the measurement of migratory speed rate (nm/h) data. Statistical analysis was conducted using one-way ANOVA and post hoc Bonferroni (p<0.05) for proliferation and post hoc LSD (p<0.05) for migration (IBM SPSS Statistics Software, version 22.0).

RESULTS: There was a statistically significant difference in hDPSC proliferation among various concentration groups of the L-Arginine based solution (300, 400 and 500 μmol/L) compared to the control group. There was a statistically significant difference in the migratory speed rate of hDPSCs in 500 μmol/L of the L-Arginine based solution group compared to lower concentrations and control group.

CONCLUSION: The highest potency of hDPSC proliferation and migration was observed in the 500 μmol/L group. (EEJ-2023-01-08).