Effect of Baicalin on Placental Tissue Damage in Preeclampsia Rats via the IL-33/ST2 Pathway

Objectives

To investigate the effect of baicalin on placental tissue injury in Preeclampsia (PE) rats and its possible mechanism.

Materials and Methods

The caudal arterial blood pressure of Ed 1 5 and Ed 2 1 rats was detected. Bradford method was used to detect the 24 hr urinary protein content. The serum levels of Tumor Necrosis Factor-α (TNF-α), Interferon-γ (IFN-γ), Interleukin-4 (IL 4), Interleukin 10 (IL 10), Interleukin-33 (IL 33) and soluble growth Stimulating expression gene 2 protein (sST2) were determined by Enzyme-Linked Immunosorbent Assay (ELISA). The number and survival rate of pups in each group were recorded. The placental tissue was separated and weighed. The histopathological changes of placenta were detected by HE staining. The apoptosis index of placental trophoblast cells was detected by TUNEI。staining. The relative expression of IL-33 and transmembrane growth Stimulation expression gene 2 protein (ST2L) in placental tissues of rats were detected by Western blotting.

Results

The looser arrangement, more obvious inflammatory infiltration, more severe apoptosis and higher serum TNF-α, IFN-γ and sST2 levels were observed. Meanwhile, the levels IL-4, IL-10 and IL-33 decreased, the relative expression level of IL-33 protein in placenta decreased, but the relative expression level of ST2L protein increased (p<0.05). Compared with the model group, the tail artery blood pressure, the 24 hr urinary protein content decreased, the number and survival rate of offspring, the pathological changes of placental tissue structure and cell apoptosis of the 4 administration groups increased. The levels of TNF-α, IFN-γ, sST2, IL-4, IL-10 and IL-33 increased. The relative expression level of IL-33 protein in placenta increased, while that of ST2L protein decreased (p<0.05). The improvement effect of baicalin on placental tissue injury was enhanced in LD, MD, HD and PD groups (p<0.05).

Conclusion

Baicalin can improve the placental tissue injury in PE rats, level of bait receptor ST2, promoting the binding of IL-33 and ST2L and regulating immune imbalance.