[Effects of icariin on expression of glucose regulated protein 78 in vascular smooth muscle cell induced by homocysteine].

Objective: To investigate the effects of icariin on the GRP78 mRNA expression of vascular smooth muscle cell in vitro and to elucidate the anti-atherosclerosis mechanism of icariin.

Method: The model was established by using half cystine in vitro. The vascular smooth muscle cell had been incubated with various concentrations of icariin for 48 hours. The apoptosis rate was detected by flow cytometry using Annexin/PI-staining and GRP78 mRNA expression was tested by RT- PCR. These differentially expressed fragments were cloned, identified and sequenced.

Result: Icariin at concentrations of 0.2 and 0.4 mg x L(-1) obviously promoted the apoptosis of vascular smooth muscle cell. The early apoptosis rate was raised magnificently in a dose dependent manner compared with that of the half cystine group (P < 0.01). Furthermore, the fragment, 648 bp, was similar to the gene of glucose regulated protein GRP78 from VSMC. Icariin could magnificently increase the GRP78 mRNA expression compared with that of the halfcystine group (P < 0.05).

Conclusion: The anti-atherosclerosis mechanism of icariin might be partly due to the promotion of apoptosis and the promotion of the GRP78 mRNA expression of vascular smooth muscle cell.