OBJECTIVETo explore the protective effect of allicin on nicotine-induced oxidative damage to human periodontal ligament cells (HPDLCs).

METHODS(1) Establish nicotine-induced oxidative damage model on HPDLCs. Use water-soluble tetrazolium (WST) colorimetric method to find out the nicotine concentration (X) that could inhibit HPDLCs' growth for the following experiments. (2) HPDLCs of the fifth passage were divided into 5 groups: The control group, the nicotine group and the nicotine+allicin groups(the concentration of allicin was 15, 30, and 60 microg x mL(-1) respectively). Different kinds of culture media were added. Similarly, use WST colorimetric method to choose the allicin concentration (Y) that could significantly improve the survival rate of HPDLCs. (3) HPDLCs were divided into 3 groups: The control group, the nicotine group, the nicotine+allicin group and different media were added. The glutathion (GSH) concentrations in HPDLCs were determined in 1, 4, 8, 12 and 24h respectively.

RESULTS0.8 mg x mL(-1) nicotine could inhibit the HPDLCs survival rate significantly (77% of the control, P < 0.05). But 60 microg x mL(-1) allicin could prevent the inhibition effects evidently, improving the survival rate to 112% of that of the nicotine group (P < 0.05) and reaching the survival rate level of control group (P > 0.05). The GSH concentrations of nicotine+allicin group were higher than that of the nicotine group always (P < 0.05) and by 82% at 8 h after culture, but had no difference with that of the control group (P > 0.05).

CONCLUSION60 microg x mL(-1) allicin can protect the HPDLCs against oxidative damage induced by nicotine.