Ramkumar Kunga Mohan, Latha Muniappan, Ashokkumar Natarajan, Pari Leelavinothan, Ananthan Rajendran
Department of Biochemistry, Faculty of Science, Annamalai University, Annamalainagar-608 002, Tamil Nadu, India.
J Basic Clin Physiol Pharmacol. 2005;16(1):17-35. doi: 10.1515/jbcpp.2005.16.1.17.
We reported that a leaf extract (GLEt) obtained from an anti-diabetic plant, Gymnema montanum, an endangered species endemic to India, has anti-peroxidative and antioxidant effects on diabetic brain tissue in rats. Here we examined the effect of the extract on the activity of reduced brain and retinal acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) in streptozotocin (STZ)-induced diabetic male Wistar rats. Diabetic rats received GLEt orally (200 mg/kg bwt/d) for 12 wk, and changes in blood glucose, plasma insulin, the lipid peroxidation marker thiobarbituric acid-reactive substance (TBARS), and AChE and BChE activity were measured. The results confirmed prior reports that hyperglycemia significantly enhances TBARS levels in brain and retinal tissue and decreases AChE and BChE activity. Treatment with GLEt significantly reversed the impairment in enzymatic activity in addition to reducing the level of TBARS, suggesting that GLEt protects against the adverse effect of lipid peroxidation on brain and retinal cholinesterases. We suggest that GLEt could be useful for preventing the cholinergic neural and retinal complications of hyperglycemia in diabetes.
我们曾报道，从一种抗糖尿病植物——匙羹藤（Gymnema montanum）（印度特有的濒危物种）中提取的叶提取物（GLEt），对大鼠糖尿病脑组织具有抗过氧化和抗氧化作用。在此，我们研究了该提取物对链脲佐菌素（STZ）诱导的糖尿病雄性Wistar大鼠脑和视网膜中还原型乙酰胆碱酯酶（AChE）及丁酰胆碱酯酶（BChE）活性的影响。糖尿病大鼠口服GLEt（200 mg/kg体重/天），持续12周，并检测血糖、血浆胰岛素、脂质过氧化标志物硫代巴比妥酸反应性物质（TBARS）以及AChE和BChE活性的变化。结果证实了先前的报道，即高血糖显著提高脑和视网膜组织中的TBARS水平，并降低AChE和BChE活性。用GLEt治疗除了降低TBARS水平外，还显著逆转了酶活性的损伤，这表明GLEt可防止脂质过氧化对脑和视网膜胆碱酯酶的不利影响。我们认为，GLEt可能有助于预防糖尿病中高血糖引起的胆碱能神经和视网膜并发症。
