ED 16. Effects of Icariin and IcarisideⅡon eNOS expression and NOS activity in porcine aorta endothelial cell

Objective: Investigated the effects of Icariin and IcarisideⅡ on eNOS expression and NOS activity in endothelial cell and possible mechanisms using EGFR over-expressed porcine aorta endothelial (PAE) cell line. Methods: The EGFR gene was transfected into PAE cell and genetic stable cell line (PAE-EGFR) was selected. 12.5 μmol/L Icariin and IcarisideⅡwere used to treat the PAE and PAE-EGFR cells respectively for 48 h, the eNOS expression in each group was observed. EGF was also used to treat the cells to observe the regulatory effects of Icariin and IcarisideⅡon NOS activity. The regulatory effects of Icariin and IcarisideⅡon NOS activity were also observed, and sildenafil was used as a control.

Results: Western blot showed that the basic value of eNOS expression was higher in PAE-EGFR group compared to that in PAE group, both of Icariin and IcarisideⅡincreased the eNOS expression in PAE and PAE-EGFR group (P<0.01), and the value of eNOS expression was higher in PAE-EGFR group than that in PAE group. In the PAE-EGFR cell line, the NOS activity reached to (15.37+1.49) U/mg when the concentration of IcarisideⅡ was 10^-8 mol/L, which was 4.66 U/mg more than that in the PAE cell line. When the concentration reached to 10^-7, 10^-6 or 10^-5 mol/ L, the change of NOS activity in PAE-EGFR group was greater than that in PAE group (P<0.01). Icariin also increased the NOS activity in PAE and PAE-EGFR cells, but the activity was 20% lower compared with IcarisideⅡ group, however, Sildenafil showed no influence on NOS activity.

Conclusions: Icariin and IcarisideⅡ may increase the eNOS expression through activating EGF-EGFR pathway in PAE cell, by which endothelial cell function could be regulated and the better effect was noted in IcarisideⅡ compared to Icariin.