[Effects of icariin and icariside II on eNOS expression and NOS activity in porcine aorta endothelial cells].

Objective: To investigate the effects of icariin and icariside II on eNOS expression and NOS activity in endothelial cells and possible mechanisms using EGFR over-expressed porcine aorta endothelial (PAE) cell line.

Methods: The EGFR gene was transfected into PAE cells and genetic stable cell line (PAE-EGFR) was selected. 12.5 μmol/L of icariin and of icariside II were 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 icariside II on NOS activity. The regulatory effects of icariin and icariside II on 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 with that in PAE group, both of icariin and icariside II increased 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 (15.37 ± 1.49) u/mg when the concentration of icariside II was 10(-8) mol/L, which was 4.66 u/mg more than that in the PAE cell line. When the concentration reached 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 icariside II group, however, Sildenafil showed no influence on NOS activity.

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