枸杞多糖对四氧嘧啶损伤的大鼠胰岛细胞的保护作用(英文)

The Protective Effects of Lycium bararum Polysaccharides on Alloxan-induced Rat Pancreatic Islets Damage

报道了枸杞多糖(Lb-PS)对4mmol/L四氧嘧啶(AXN)损伤的离体培养的大鼠胰岛细胞的保护作用。实验分为正常对照素、AXN损伤组和Lb-PS保护组。采用放射免疫分析法测定胰岛细胞内胰岛素水平以及葡萄糖刺激的胰岛素释放水平。分光光度比色法测定细胞内SOD和葡萄糖激酶的活性,以及培养基中NO和MDA的含量。结果表明,AXN显著抑制细胞内的胰岛素合成和葡萄糖刺激的胰岛素释放,以及SOD和葡萄糖激酶的活性。AXN促使培养基中NO和MDA浓度的显著增加。在同时加入AXN和10-5￣10-2mg/ml Lb-PS的实验组中,均发现能不同程度地保护胰岛细胞免受AXN的损伤。Lb-PS能恢复AXN损伤的胰岛细胞的胰岛素合成和释放水平,以及SOD和葡萄糖激酶的活性,使其基本达到正常对照组的水平。Lb-PS还能降低培养基中NO和MDA的浓度。因此,Lb-PS可能通过减少胰岛β细胞的NO产量和维持SOD和葡萄糖激酶的活性,最终起到保护胰岛素合成和释放功能的作用。

To study the protective effects of Lycium bararum polysaccharides (Lb-PS) on isolated pancreatic islets which were incubated with 4 mmol/L alloxan (AXN), Insulin released into medium and in islets was detected by radioimmunoassay and glucokinase and SOD activity, NO and malonaldehyde (MDA) production were measured by colorimetric assay. Results indicated that AXN significantly inhibited the insulin release in response to glucose and insulin content in islets. In addition, there was a higher NO and MDA concentration and reduced glucokinase and SOD activity in islets incubated with AXN. Lb-PS could restore glucokinase and SOD activity, insulin synthesis and secretion inhibited by AXN, and reduce NO and MDA production in AXN-induced islets. Therefore Lb-PS could protect glucose-induced insulin synthesis and insulin secretion through reducing NO production and maintaining glucokinase and SOD activity in pancreatic β cells.