Sena Cristina M, Nunes Elsa, Gomes Aline, Santos Maria S, Proença Teresa, Martins Maria I, Seiça Raquel M
Institute of Physiology, Faculty of Medicine, University of Coimbra, 3000-354 Coimbra, Portugal.
Nutr Res. 2008 Feb;28(2):113-21. doi: 10.1016/j.nutres.2007.12.005.
The importance of nutritional supplementation in diabetes remains an unresolved issue. The present study was undertaken to examine the effects of alpha-tocopherol and CoQ(10), powerful antioxidants, on metabolic control and on the pancreatic mitochondria of GK rats, a model of type 2 diabetes. We also evaluated the efficacy of these nutrients in preventing the diabetic pancreatic lesions observed in GK rats. Rats were divided into 4 groups, a control group of diabetic GK rats and 3 groups of GK rats administered with alpha-tocopherol and CoQ(10) alone or both in association, during 8 weeks. Fasting blood glucose levels were not significantly different between the groups, nor were blood glucose levels at 2 hours after a glucose load. HbA1c level was significantly reduced in the group supplemented with both antioxidants. Diabetes induced a decrease in coenzyme Q plasma levels that prevailed after treatment with antioxidants. In addition, the plasma alpha-tocopherol levels were higher after treatment with the antioxidants. An increment in some components of the antioxidant defense system was observed in pancreatic mitochondria of treated GK rats. Moreover, the antioxidants tested either alone or in association failed to prevent the pancreatic lesions in this animal model of type 2 diabetes. In conclusion, our results indicate that CoQ(10) and alpha-tocopherol decrease glycated HbA1c and pancreatic lipid peroxidation. These antioxidants increase some components of the antioxidant defense system but do not prevent pancreatic lesions. Thus, we cannot rule out the potential benefit of antioxidant treatments in type 2 diabetes in the prevention of their complications.
营养补充在糖尿病治疗中的重要性仍是一个未解决的问题。本研究旨在探讨α-生育酚和辅酶Q10（两种强效抗氧化剂）对GK大鼠（一种2型糖尿病模型）代谢控制及胰腺线粒体的影响。我们还评估了这些营养素在预防GK大鼠糖尿病胰腺病变方面的效果。大鼠被分为4组，一组为糖尿病GK大鼠对照组，另外3组GK大鼠在8周内单独给予α-生育酚或辅酶Q10，或两者联合使用。各组间空腹血糖水平无显著差异，葡萄糖负荷后2小时的血糖水平也无显著差异。同时补充两种抗氧化剂的组中糖化血红蛋白（HbA1c）水平显著降低。糖尿病导致辅酶Q血浆水平下降，抗氧化剂治疗后这种下降仍然存在。此外，抗氧化剂治疗后血浆α-生育酚水平升高。在接受治疗的GK大鼠胰腺线粒体中，观察到抗氧化防御系统的某些成分有所增加。此外，单独或联合使用的抗氧化剂均未能预防该2型糖尿病动物模型中的胰腺病变。总之，我们的结果表明，辅酶Q10和α-生育酚可降低糖化HbA1c水平及胰腺脂质过氧化。这些抗氧化剂增加了抗氧化防御系统的某些成分，但不能预防胰腺病变。因此，我们不能排除抗氧化剂治疗在2型糖尿病预防并发症方面的潜在益处。
