Department of Pharmaceutical Engineering, College of Life Science and Biotechnology, Heilongjiang August First Land Reclamation University, Daqing High-Tech Industrial Development Zone, 163319, P. R. China.
Can J Physiol Pharmacol. 2009 Sep;87(9):711-9. doi: 10.1139/y09-068.
Lycium barbarum polysaccharide (LBP) has been shown to have hypoglycemic and antioxidative properties, although its mode of action is yet unknown. Because oxidative stress is implicated in the pathogenesis of diabetic nephropathy, we evaluated the protective effect of LBP-4, the major active component of Lycium barbarum, on the defensive antioxidative mechanism in kidneys in a streptozotocin-induced diabetic rat model. Moreover, we investigated the effects of LBP-4 on the activation of extracellular signal-regulated kinases 1 and 2 (ERK1/2) in isolated mesangial cells. The role of protein kinase C (PKC)-dependent and -independent pathways in LBP-4-reduced ERK1/2 was studied by bisindolylmaleimide (BIM) IV, an inhibitor of PKC. Diabetic rats treated with LBP-4 (10 mg/kg) for 8 weeks showed increased activity of antioxidant enzymes and increased scavenging of oxygen radicals, while the activity of PKC in the renal cortex was maintained at a physiological level. The decreased activation of ERK1/2 in mesangial cells, through the involvement of PKC, could explain the protective mechanism in kidneys of diabetic rats treated with LBP-4.
枸杞多糖（LBP）已被证明具有降血糖和抗氧化作用，尽管其作用机制尚不清楚。由于氧化应激与糖尿病肾病的发病机制有关，我们评估了枸杞中主要活性成分枸杞多糖-4（LBP-4）对链脲佐菌素诱导的糖尿病大鼠模型肾脏防御抗氧化机制的保护作用。此外，我们还研究了 LBP-4 对分离的系膜细胞中细胞外信号调节激酶 1 和 2（ERK1/2）的激活作用的影响。通过蛋白激酶 C（PKC）依赖性和非依赖性途径抑制剂双吲哚马来酰亚胺（BIM）IV 研究了 LBP-4 降低 ERK1/2 的作用。8 周给予 LBP-4（10mg/kg）治疗的糖尿病大鼠表现出抗氧化酶活性增加和氧自由基清除增加，而肾皮质中的 PKC 活性保持在生理水平。PKC 参与介导系膜细胞中 ERK1/2 的活性降低，这可以解释 LBP-4 治疗糖尿病大鼠肾脏的保护机制。
