dl-3n-butylphthalide reduces oxygen-glucose deprivation-induced endothelial cell damage by increasing PGC-1α.

OBJECTIVE: Animal experiments verified that dl-3-n-butylphthalide (NBP) can protect vascular endothelial cells from ischemic damage and promote vascular proliferation in ischemic stroke treatment, but the underlying mechanism has not been fully clarified. This study aimed to investigate the effects of NBP on peroxisome proliferators-activated receptor-γ coactivator-1α (PGC-1α) expression in endothelial cells exposed to oxygen-glucose deprivation (OGD) and to clarify the related molecular mechanism. MATERIALS AND METHODS: SV40-transformed aortic rat endothelial cell line was cultured and subjected to OGD in the presence or absence of NBP. The cell viability was evaluated by using thiazolyl blue tetrazolium bromide (MTT) method. The cellular endothelial nitric oxide synthase (eNOS) activity was measured by using eNOS activity assay. The nuclear changes were assessed with Hoechst 33342 fluorescent dye. The immunofluorescence analysis and Western blotting assay were conducted to evaluate the protein expression. RESULTS: We found that NBP could significantly prevent endothelial cells from OGD-induced injuries, in terms of cell morphology and cell viability. Both immunofluorescence analysis and Western blot findings confirmed that the NBP treatment further enhanced PGC-1α expression during OGD, which was prevented in the presence of selective endothelial nitric oxide synthetase (eNOS) inhibitor N5-(1-Iminoethyl)-L-ornithine-HCL (L-NIO). Furthermore, we found that NBP could protect the eNOS activity about by 40% during OGD and did not influence the eNOS protein level in the spectrophotometric-based analysis. CONCLUSIONS: NBP maintained the endothelial PGC-1α expression via regulating eNOS activity during the exposure to OGD; therefore, it presented its protective function to cell viability and vascular proliferation.