NATURAL PRODUCT RESEARCH AND DEVELOPMENT ›› 2015, Vol. 27 ›› Issue (5): 785-792. doi: 10.16333/j.1001-6880.2015.05.007

Special Issue: No.6

• Article • Previous Articles     Next Articles

Echinocystic Acid,Extracted from Gleditsia sinensis Fruit,Protects Endothelial Progenitor Cell from Damage Caused by OxLDL,through the Akt/eNOS pathway

LAI Peng1*, LIU Yi-xin2   

  1. 1 School of Bioengineering,Xihua University,Chengdu 610039,China;2 Department of Geriatrics,West China hospital,Sichuan University,Chengdu 610041,China
  • Online:2015-05-30 Published:2015-06-05

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Abstract: Our previous studies revealed that echinocystic acid (EA) showed obvious attenuation of atherosclerosis in rabbits fed a high-fat diet.However,the underlying mechanisms remain to be elucidated.Considering the importance of endothelial progenitor cells (EPCs) in atherosclerosis,we hypothesise that EPCs may be one of the targets for the anti-atherosclerotic potential of EA.After in vitro cultivation,EPCs were exposed to 100 μg/mL oxidised low-density lipoprotein (oxLDL) and incubated with or without EA (5 and 20 μM) for 48 h.An additional two groups of EPCs (oxLDL + 20 μM EA) were pre-treated with either wortmannin,an inhibitor of the phosphoinositide 3-kinase (PI3K) pathway,or nitro-l-arginine methyl ester (l-NAME),an endothelial nitric oxide synthase (eNOS)-specific inhibitor.Assessment of EPC apoptosis,adhesion,migration and nitric oxide (NO) release was performed using terminal deoxynucleotidyl transferase-mediated dUTP nick-end labelling (TUNEL) staining,cell counting,caspase-3 activity assay,transwell chamber assay and Griess reagent,respectively.The protein expression of protein kinase B (Akt) and eNOS was detected using western blot.Treatment of EPCs with oxLDL induced significant apoptosis (Model,35.2%,vs.Control,6.4%) and impaired adhesion (Model,14,vs.Control,24),migration (Model,6.6%,vs.Control,11%) and NO production (Model,7.97 μM,vs.Control,18.37 μM).The deleterious effects of oxLDL on EPCs were attenuated by EA (apoptosis ratio:14.7%,adhesion cells:20,migration ratio:10.2%,NO production:19.28μM).However,when EPCs were pre-treated with wortmannin or l-NAME,the effects of EA were abrogated.Additionally,oxLDL significantly downregulated eNOS protein expression,as well as repression of eNOS and Akt phosphorylation.The inhibitory effect of oxLDL on Akt/eNOS phosphorylation was attenuated by EA.Taken together,the results indicated that EA protects EPCs from damage caused by oxLDL,via the Akt/eNOS pathway.

Key words: endothelial progenitor cells, echinocystic acid, oxidized low density lipoprotein, Akt/eNOS

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