蒺藜皂苷对糖基化终产物形成及其诱导的内皮细胞功能障碍影响研究

本文探讨蒺藜皂苷(STT)对糖基化终产物(AGEs)形成及AGEs诱导的内皮细胞功能障碍的影响。以荧光法检测AGEs体外形成,MTT法检测细胞存活率,试剂盒方法检测细胞及培养上清液中的一氧化氮(NO)水平、诱导型NO合酶(iNOS)活力和超氧阴离子水平(O2-.)。结果显示STT促进AGEs形成,并加剧AGEs诱导的内皮细胞生长抑制,提高细胞NO分泌,增加iNOS活力和O2-.水平。与海可、替告皂苷元作用进行比较,发现STT的细胞损伤作用可能是海可皂苷元引起的。提示STT未能抑制体外AGEs形成,对AGEs引起的内皮细胞功能障碍无明显保护作用,反而可能通过增强iNOS酶活加剧细胞损伤。

Effects of Saponins from Tribulus terrestris L.on Nonenzymatic Glycation and Endothelial Cell Dysfunction

Previous researches have confirmed that saponins from Tribulus terrestris L.(STT) is effective in controlling serum glucose and lipid levels.The present study investigated the effect of STT on advanced glycation end products(AGEs) formation and AGEs-mediated endothelial cell dysfunction.Fluorescence detection was used to monitor the Maillard reaction.Primary cultured bovine aortic endothelial cells(BAECs) were exposed to 100 μg/mL AGEs for 30 min followed by STT supplementation.Cell viability was detected by MTT assay,whereas cellular nitric oxide(NO) release,enzymatic activity of NO synthase(NOS),and levels of superoxide were monitored by reagent kit.Data showed that STT increased the formation of AGEs at 10 μg/mL.The supplementation of STT also accelerated the decrease in BAECs viability regardless of cell exposure to AGEs.Furthermore,STT elevated the AGEs-induced decline in NO release,as well as increased inducible NOS(iNOS) activities and superoxide levels.Compared with the effects of hecogenin and tigogenin,the negative effect of STT on AGEs-injured BAECs might be ascribed to hecogenin.Our findings suggested that STT was not a suitable candidate for inhibiting nonenzymatic glycation,and it accelerated the AGEs-mediated endothelial cell dysfunction probably by enhancing iNOS activity.