Department of Biochemistry and Biotechnology, Faculty of Science, Annamalai University, Annamalainagar 608 002, Tamilnadu, India.
Chem Biol Interact. 2011 Apr 25;190(2-3):148-54. doi: 10.1016/j.cbi.2011.02.029. Epub 2011 Mar 5.
The present study was aimed to investigate the effect of thymoquinone (TQ) on pancreatic insulin levels, tissue antioxidant and lipid peroxidation (LPO) status in streptozotocin (STZ) nicotinamide (NA) induced diabetic rats. Diabetes was induced in experimental rats by a single intraperitoneal (i.p) injection of STZ (45 mg/kg b.w) dissolved in 0.1 mol/L citrate buffer (pH 4.5), 15 min after the i.p administration of NA (110 mg/kg b.w). Diabetic rats exhibited increased blood glucose with significant decrease in plasma insulin levels. The activities of antioxidant enzymes catalase (CAT), glutathione peroxidase (GPx), glutathione-S-transferase (GST) and the levels of low-molecular weight antioxidants Vitamin C, Vitamin E and reduced glutathione (GSH) were decreased while increases in the levels of lipid peroxidation markers were observed in liver and kidney tissues of diabetic control rats as compared to control rats. In addition, diabetic rats showed an obvious decrease in pancreatic insulin levels. Administration of TQ (80 mg/kg b.w) to diabetic rats for 45 days significantly reversed the damage associated with diabetes. Biochemical findings were supported by histological studies. These results indicated that TQ exerts a protective action on pancreatic beta cell function and overcomes oxidative stress through its antioxidant properties.
本研究旨在探讨姜黄素（TQ）对链脲佐菌素（STZ）-烟酰胺（NA）诱导的糖尿病大鼠胰腺胰岛素水平、组织抗氧化和脂质过氧化（LPO）状态的影响。实验大鼠通过腹腔内（i.p）注射 STZ（45mg/kg b.w）在 NA（110mg/kg b.w）给药 15 分钟后溶解在 0.1mol/L 柠檬酸盐缓冲液（pH4.5）中诱导糖尿病。糖尿病大鼠表现出血糖升高，血浆胰岛素水平显著降低。与对照组大鼠相比，糖尿病对照组大鼠肝脏和肾脏组织中的抗氧化酶过氧化氢酶（CAT）、谷胱甘肽过氧化物酶（GPx）、谷胱甘肽-S-转移酶（GST）的活性以及低分子量抗氧化剂维生素 C、维生素 E 和还原型谷胱甘肽（GSH）的水平降低，而脂质过氧化标志物的水平增加。此外，糖尿病大鼠胰腺胰岛素水平明显下降。TQ（80mg/kg b.w）连续 45 天给药可显著逆转糖尿病相关损伤。生化发现得到组织学研究的支持。这些结果表明，TQ 通过其抗氧化特性对胰岛β细胞功能发挥保护作用，并克服氧化应激。
