Regulatory effect of daphnetin on the balance of Th17 and Treg cells in the peripheral blood mononuclear cells from patients with unexplained recurrent pregnancy loss

Introduction: There has a close relationship between the balance of T helper 17 (Th17) cells and Foxp3+ regulatory T cells (Treg) and unexplained recurrent pregnancy loss (URPL). The present study is to investigate the regulatory effect of daphnetin, which is extracted from Daphne odora Var, on the balance of Th17 and Treg cells in the peripheral blood mononuclear cells (PBMCs) from patients with URPL. Material and methods: PBMCs were isolated from 35 pregnant women with URPL and 35 women with normal early pregnancies, respectively and treated with daphnetin for three days. Flow cytometry was performed to measure the proportions of Th17 and Treg cells. The level of expression of IL-6, TGF-beta 1 and IL-2 were detected using enzyme-linked immunosorbent assay (ELISA) and the level of expression of FoxP3, ROR gamma t, signal transducers and activators of transcriotion 3 (STAT3) and STAT5 were detected by RT-PCR. Results: The concentrations of Th17-type cytokines IL-2 were significantly decreased in the URPL group after treatment (p < 0.01). Treg-type cytokines such as TGF-beta 1 and IL-6 were significantly increased after treatment (p < 0.01). At the same time, daphnetin may induce a decrease in the ratio of ROR gamma t to Foxp3 and a Treg cell bias, which would be beneficial for pregnancy maintenance. Futher-more the expression level of STAT3 were higher in the URPL patients whereas STAT5 were lower than those in the control subjects. Conclusions: In conclusion, daphnetin may have regulatory effect on the balance of Th17 and Treg cells in the peripheral blood mononuclear cells from patients with URPL.