Ramkumar K M, Rajaguru P, Latha M, Ananthan R
Department of Biotechnology, School of Engineering and Technology, Bharathidasan University, Tiruchirapalli 620 024, Tamil Nadu, India.
Cell Biol Toxicol. 2008 Jun;24(3):233-41. doi: 10.1007/s10565-007-9032-z. Epub 2007 Sep 19.
The aim of the present study was to evaluate the protective effect of Gymnema montanum on red blood cell (RBC) membrane in diabetic rats during lipid peroxidation. Ethanol extract of G. montanum leaves (GLEt) was administered orally to alloxan-induced diabetic rats for 3 weeks, and the effects on blood glucose, insulin, lipid peroxidation markers, thiobarbituric acid reactive substances, hydroperoxides in plasma and antioxidant enzymes including superoxide dismutase, catalase and glutathione peroxidase activities in erythrocytes were studied. Administration of GLEt to diabetic animals at doses of 50, 100, and 200 mg/kg body weight lowered elevated blood glucose levels by 24, 35, and 66%, respectively, relative to untreated diabetic rats. In comparison, treatment with the known antidiabetic drug, glibenclamide (600 microg/kg body weight) decreased blood glucose concentrations by 51%. Plasma insulin concentrations were increased in the diabetic rat by 73% with GLEt (200 mg/kg body weight) and 45% with glibenclamide (600 microg/kg body weight). Although a significant decrease in the lipid peroxidation markers was observed in plasma on treatment with GLEt and glibenclamide, the RBC antioxidant levels were increased significantly in diabetic rats. Furthermore, erythrocytes from the GLEt-treated animals were found to be more resistant to H2O2-induced peroxidation than that of untreated diabetic animals. The chemical characterization of the polyphenolics of the extract showed the presence of gallic acid (5.29% w/w), resveratrol (2.2% w/w), and quercetin (16.6% w/w). The results of this study suggest that G. montanum may be useful for the control, management, and prevention of oxidative stress associated with diabetes.
本研究的目的是评估蒙山药对糖尿病大鼠脂质过氧化过程中红细胞（RBC）膜的保护作用。将蒙山药叶乙醇提取物（GLEt）口服给予四氧嘧啶诱导的糖尿病大鼠3周，研究其对血糖、胰岛素、脂质过氧化标志物、血浆中硫代巴比妥酸反应物质、氢过氧化物以及红细胞中抗氧化酶（包括超氧化物歧化酶、过氧化氢酶和谷胱甘肽过氧化物酶活性）的影响。以50、100和200mg/kg体重的剂量给糖尿病动物施用GLEt，相对于未治疗的糖尿病大鼠，血糖水平分别降低了24%、35%和66%。相比之下，用已知的抗糖尿病药物格列本脲（600μg/kg体重）治疗可使血糖浓度降低51%。糖尿病大鼠血浆胰岛素浓度用GLEt（200mg/kg体重）升高了73%，用格列本脲（600μg/kg体重）升高了45%。虽然在用GLEt和格列本脲治疗后血浆中的脂质过氧化标志物显著降低，但糖尿病大鼠的红细胞抗氧化水平显著提高。此外，发现用GLEt处理的动物的红细胞比未治疗的糖尿病动物的红细胞对H2O2诱导的过氧化更具抗性。提取物中多酚类物质的化学表征显示存在没食子酸（5.29%w/w）、白藜芦醇（2.2%w/w）和槲皮素（已删除重复内容，16.6%w/w）。本研究结果表明，蒙山药可能有助于控制、管理和预防与糖尿病相关的氧化应激。
