Antidiabetic and Antioxidative Effects of Jatropha curcas Extracts in Streptozotocin-induced Diabetic Rats

Abstract

Aims: To ascertain the antidiabetic and antioxidative effects of ethanol-methanol extracts of leaf, stem bark and root of Jatropha curcas on the blood and liver tissue of streptozotocin-induced diabetic albino wistar rats Place and Duration of Study: Department of Medical Biochemistry, Cross River University of Technology, Okuku campus between August 2013 and March, 2014. Methodology: Fifty four (54) male albino wistar rats weighing 150- 200g were randomly assigned into nine study groups (n=6). Group I was the normal control, groups II–VI were induced with diabetes using streptozotocin. Group II was untreated, while groups III –VI were treated with leaf, stem bark, root extracts and Glibenclamide (standard drug) respectively. The remaining groups VII-IX were not induced with diabetes but were treated with leaf, stem bark and root extracts respectively. The administration of these extracts lasted for 14 days after which the animals were sacrificed. The liver tissue was collected and homogenized and the supernatant used for the estimation of SOD, CAT and MDA activities. Results: The result of blood glucose level on the fourteenth day of the plant extracts administration, showed further decrease in the groups treated with the plant extracts to the extent that group IV was significantly (P<0.05) decreased compared with the normal control. The blood glucose level of the standard drug (Glibenclamide) treated group (VI) was further decreased however it remained significantly (P<0.05) increased compared with the normal control and about three or more times that of the groups treated with the plant extracts. Result of the liver tissue SOD for the test groups showed significant (P<0.05) difference except for groups IV and VII when compared with the normal control. There was no significant (P≥0.05) difference in the SOD activities of test groups compared with the diabetic control. The liver tissue CAT showed general increase for the test groups, but group III produced a significant (P<0.05) increase compared with the normal control, while groups III and V showed significant (P<0.05) increase compared with the diabetic control. The liver tissue MDA showed significant (P<0.05) increase for groups II and IV but a significant (P<0.05) decrease for group V compared with the normal control. However, compared with group II (diabetic control) all the test groups showed a significant (P<0.05) decrease. Conclusion: The present research suggest that the leaf, stem bark and root of ethanol-methanol (1:1) extracts of Jatropha curcas possess anti-hyperglycemic and antioxidant activities but their response to the liver tissue enzyme systems of SOD and CAT vary in either to playing compensatory role or boosting the activities of the antioxidant enzymes. The plant parts also appear to possess the potential for reversing the tissue oxidative damage caused by diabetes as seen by their abilities to prevent lipid peroxidation.