Study Of Injury Of Human Dental Pulp Cells Mediated By Lipopolysaccharide And Protective Effects Of Baicalin

ObjectiveTo observe the expression of Toll-like receptor 4(TLR4) and the secretion of tumor necrosis factor alpha(TNF-α) in human dental pulp cells(HDPCs) mediated by lipopolysaccharide(LPS),and to determine the signal transduction pathway of LPS in pulpitis. Then try to study the effects of baicalin on HDPCs and the mechanism of the effects.MethodsHDPCs were primarily cultured in vitro and identified their phenotype by immunohistochemcial staining.HDPCs were devided into four groups:(1)control group; (2) LPS group;(3)baicalin group;(4)baicalin and LPS group.Flow Cytometry(FC) was used to analyse the expression of TLR4 and enzyme-labeled immunosorbent assay(ELISA) was used to measure the secretion of TNF-α.The experimental data were subjected to statistical analysis.Results1 TLR4 and TNF-αwere detected weakly in healthy HDPCs.2 The expressions of TLR4 and TNF-αin the group of LPS at 100μg/ml increased significantly compared with the control group(P＜0.01).3 The expressions of TLR4 and TNF-αhad no statistical differences between the control group and the group of baicalin at 10μg/ml(P＞0.05).4 Baicalin at the concentrations from 0.001 to 20μg/ml can significantly inhibit the expressions of TLR4 and TNF-αmediated by LPS in a dose-dependent manner compared with the LPS group(P＜0.01).Among the different baicalin concentrations the differences of expressions of TLR4 and TNF-αwere statistically significant(P＜0.01), except the concentrations at 10μg/ml and 20μg/ml(P＞0.05).Conclusions1 These results revealed that LPS may participate in the inflammation of pulp tissue by TLR4.2 Baicalin may be promising in the treatment of pulpitis mediated by LPS with inhibiting the expression of TLR4 and secretion of TNF-α.