RESUMEN
Objective To observe the regulatory effect of glycyrrhizin on the expression of IFN-γ and TNF-β in peripheral blood mononuclear cells (PBMCs) of patients with alopecia areata.Methods PBMCs were obtained from 18 patients with mild alopecia areata,24 patients with severe alopecia areata and 20 normal human controls,and cultured with phytohemagglutinin (PHA) or the combination of PHA and glycyrrhizin for 24 hours.Then,reverse transcription (RT)-PCR was conducted to detect the mRNA expression of IFN-γand TNF-β in these cells.Results The mRNA expression levels of IFN-γand TNF-β in PBMCs were significantly higher in patients with severe alopecia areata than in those with mild alopecia areata and normal human controls (all P ＜ 0.05),and higher in patients with mild alopecia areata than in normal human controls (both P ＜ 0.05).A significant decrease was observed in the mRNA expressions of IFN-γ and TNF-β in the PBMCs from patients with alopecia areata after stimulation with the combination of PHA and glycyrrhizin (both P ＜0.05).Conclusion Glycyrrhizin can inhibit the expression of Th1-type cytokines and reverse Th1-type immune response.