Hypoglycemic effect of okra aqueous extract on streptozotocin-induced diabetic rats

Abstract Okra (AbelmoschusesculentusL.Moench) is widely planted in subtropical and tropical areas, with good palatability and a variety of biological activities. However, the hypoglycemic activity of okra aqueous extract and its mechanism were still unclear. In this paper, the hypoglycemic effect of okra aqueous extract on type 1 diabetic rats induced by streptozotocin (STZ) was investigated. The growth indicators, blood physiological and biochemical indicators (such as blood glucose, glucose tolerance, serum lipids, insulin, pyruvate kinase activity), histopathology of liver and pancreas were determined. Comparing with streptozotocin-induced diabetic rats group, the aqueous extract of okra treatment group exhibited decreasing blood glucose level (10.11%), glucose tolerance (12.00%), total triglyceride (41.59%), atherosclerosis index (49.20%), urine sugar (91.91%) and increasing insulin secretion (17.44%) and pyruvate kinase activity (57.41%). Okra aqueous extract significantly ameliorated STZ-induced steatosis of hepatocytes and islet cells. But, the feed intake, water intake, urine volume, and body weight of okra aqueous extract treated groups were not significantly different with those in normal rats groups or diabetic rats group, respectively. Therefore, the aqueous extract of okra was responsible for promoting insulin secretion, increasing pyruvate kinase activity and reducing blood glucose and lipid level.

摘要：秋葵（Abelmoschus esculentus L. Moench）在亚热带与热带地区广泛种植，兼具优良适口性与多种生物活性。然而，秋葵水提物的降血糖活性及其作用机制仍未明晰。本研究探讨了秋葵水提物对链脲佐菌素（streptozotocin，STZ）诱导的1型糖尿病大鼠的降血糖功效。实验测定了大鼠的生长指标、血液生理生化指标（包括血糖、糖耐量、血脂、胰岛素水平、丙酮酸激酶活性）以及肝脏与胰腺的组织病理学特征。与链脲佐菌素诱导的糖尿病模型组大鼠相比，秋葵水提物干预组的血糖水平（下降10.11%）、糖耐量（下降12.00%）、总甘油三酯（下降41.59%）、动脉粥样硬化指数（下降49.20%）及尿糖水平（下降91.91%）均显著降低，同时胰岛素分泌量（提升17.44%）与丙酮酸激酶活性（提升57.41%）显著升高。秋葵水提物可显著改善链脲佐菌素诱导的肝细胞与胰岛细胞脂肪变性。但秋葵水提物干预组的摄食量、饮水量、排尿量及体质量，分别与正常对照组大鼠、糖尿病模型组大鼠无显著统计学差异。综上，秋葵水提物可通过促进胰岛素分泌、提升丙酮酸激酶活性，进而降低血糖与血脂水平。