Antihyperglycaemic and anti-oxidant properties of Andrographis paniculata in normal and diabetic rats.
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.
Zhang
X F
XF
Department of Pharmacology, Faculty of Medicine, National University of Singapore, Singapore.
Tan
B K
BK
D000818:Animals; D000900:Anti-Bacterial Agents; D000975:Antioxidants / Q000493:pharmacokinetics / Q000627:therapeutic use*; D001835:Body Weight / Q000187:drug effects / Q000502:physiology; D003921:Diabetes Mellitus, Experimental / Q000188:drug therapy* / Q000378:metabolism; D005215:Fasting / Q000378:metabolism; D007004:Hypoglycemic Agents / Q000493:pharmacokinetics / Q000627:therapeutic use*; D007668:Kidney / Q000187:drug effects / Q000378:metabolism; D008099:Liver / Q000187:drug effects / Q000378:metabolism; D008297:Male; D008687:Metformin / Q000493:pharmacokinetics / Q000627:therapeutic use; D018384:Oxidative Stress / Q000187:drug effects / Q000502:physiology*; D010936:Plant Extracts / Q000493:pharmacokinetics / Q000627:therapeutic use*; D051381:Rats; D017207:Rats, Sprague-Dawley; D013311:Streptozocin
D000900:Anti-Bacterial Agents; D000975:Antioxidants; D007004:Hypoglycemic Agents; D010936:Plant Extracts; D013311:Streptozocin; D008687:Metformin