Antihyperglycaemic And Anti-Oxidant Properties Of Andrographis Paniculata In Normal And Diabetic Rats

• Published in: Clinical and experimental pharmacology & physiology 2000-05, Vol.27 (5-6), p.358-363
• Main Authors: Zhang, Xiang-Fan, Tan, Benny Kwong-Huat
• Format: Article
• Language: English
• Subjects: Andrographis paniculata; Animals; Anti-Bacterial Agents; antihyperglycaemic; Antioxidants - pharmacokinetics; Antioxidants - therapeutic use; Body Weight - drug effects; Body Weight - physiology; catalase; Diabetes Mellitus, Experimental - drug therapy; Diabetes Mellitus, Experimental - metabolism; diabetic rat; Fasting - metabolism; glutathione; glutathione peroxidase; Hypoglycemic Agents - pharmacokinetics; Hypoglycemic Agents - therapeutic use; Kidney - drug effects; Kidney - metabolism; Liver - drug effects; Liver - metabolism; Male; Metformin - pharmacokinetics; Metformin - therapeutic use; oxidative stress; Oxidative Stress - drug effects; Oxidative Stress - physiology; Plant Extracts - pharmacokinetics; Plant Extracts - therapeutic use; Rats; Rats, Sprague-Dawley; Streptozocin; superoxide dismutase; thiobarbituric acid-reactive substances
• ISSN: 0305-1870; 1440-1681
• DOI: 10.1046/j.1440-1681.2000.03253.x

SUMMARY 1. Oxidative stress is believed to be a pathogenetic factor in the development of diabetic complications. In the present study, we investigated the ethanolic extract of the aerial parts of Andrographis paniculata for antihyperglycaemic and anti‐ oxidant effects in normal and streptozotocin‐induced type I diabetic rats. 2. Normal and diabetic rats were randomly divided into groups and treated orally by gavage with vehicle (distilled water), metformin (500 mg/kg bodyweight) or the extract (400 mg/kg bodyweight), twice a day for 14 days. 3. At the end of the 14 day period, the extract, like metformin, significantly increased bodyweight (P < 0.01) and reduced fasting serum glucose in diabetic rats (P < 0.001) when compared with vehicle, but had no effect on bodyweight and serum glucose in normal rats. Levels of liver and kidney thiobarbituric acid‐ reactive substances (TBARS) were significantly increased (P < 0.0001, P < 0.01, respectively), while liver glutathione (GSH) concentrations were significantly decreased (P < 0.005) in vehicle‐treated diabetic rats. Liver and kidney TBARS levels were significantly lower (P < 0.0001, P < 0.005, respectively), whereas liver GSH concentrations were significantly higher (P < 0.05) in extract‐ and metformin‐treated diabetic rats compared with vehicle‐treated diabetic rats. Andrographis paniculata significantly decreased kidney TBARS level (P < 0.005) in normal rats. Hepatic superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GSH‐Px) activities were significantly lower in vehicle‐treated diabetic rats compared with vehicle‐treated normal rats. The extract, as well as metformin, significantly increased the activity of SOD and CAT, but had no significant effect on GSH‐Px activity in diabetic rats. The extract and metformin did not produce significant changes in the activity of these anti‐oxidant enzymes in normal rats. 4. Our results show that oxidative stress is evident in streptozotocin‐diabetic rats and indicate that the ethanolic extract of A. paniculata not only possesses an antihyperglycaemic property, but may also reduce oxidative stress in diabetic rats.