Expression of NKG2D Receptors in CD3+ and CD56+ Cells in Blood Samples of Pre-eclampsia Patients and the Effect of Silymarin on Their Activity in Vitro

Increased NK cells or their cytokine activity in endometrium and peripheral blood of mothers with pre-eclampsia have been reported. NKG2D is a cell surface receptor that can be used to detect NK cell and lymphocytic activity. Plant flavonoids such as silymarin has immunomodulatory effects and potentially inhibit the disease progression. Therefore, an in vitro experiment was designed to investigate the immunomodulatory effects of silymarin in pre-eclampsia.

Blood samples from preeclamptic and pregnant and non-pregnant women were analyzed by Isolation of peripheral blood mononuclear cells (PBMCs) using Ficoll-Paque. Flow cytometry was used for marker assay including NKG2D expression on CD56+CD3- and CD3+ cells. Also, different concentrations of silymarin were applied, andNKG2D expression on the cells were considered, and IFNγ production in the cell culture medium were evaluated using ELISA.

CD3-CD56+ cells and NKG2D receptor expression were augmented in PBMCs in the pre-eclampsia group (P = 0.03). However, treatment of PBMCs with silymarin solutions decrease NKG2D markers on the lymphocytes. PBMCs treated cells by silymarin in culture medium indicates reduce IFNɣ production even in the presence of IL-2 stimulation by 2-3 folds (P = 0.0001).

Increase in NK cell population, NKG2D receptor expression and IFNɣ production play a crucial role in the samples of preeclamptic patients, and well express involvement of immunological factors of the disease. The effectiveness of silymarin in cell culture medium and modulation of inflammatory factors necessitate the design of clinical model for using silymarin in patients by risk of increased NK activity in pre-eclampsia patients.