Original Article Modulatory effect of Mengkudu fruit on the activities of key enzymes of glucose synthesis and utilization pathways of diabetic induced rats Mainul Haque a , U.S. Mahadeva Rao b, * a Professor, Faculty of Medicine and Health Science, Universiti Sultan Zainal Abidin, Malaysia b Associate Professor, Faculty of Medicine and Health Science, Universiti Sultan Zainal Abidin, Kampus Kota, Jalan Sultan Mahmud, 20400 Kuala Terengganu, Terengganu, Malaysia article info Article history: Received 12 November 2012 Accepted 9 January 2013 Available online 5 February 2013 Keywords: Mengkudu fruit extract Glucose utilization Diabetes Streptozotocin abstract Objective: The present study was aimed to screen the secondary metabolites and evaluate the ameliorative potential of ethanolic extract of Morinda citrifolia (Mengkudu) Fruit Extract (MFE) on the glucose synthesis and utilization reactions. Methods: The phytochemicals present in the Mengkudu fruit extract were qualitatively investigated. The blood glucose, glycogen content, and plasma insulin profiles and the ac- tivities of the key enzymes of glucose oxidation, and gluconeogenic pathways and glycogen metabolism in liver and kidney tissues in streptozotocin (STZ) induced experimental diabetic albino rats were assessed. Results: The diabetic rats orally treated with MFE (300 mg/kg b.w./day) for 30 days resulted in significant plunge in blood glucose, glycosylated hemoglobin levels and upswing in glycogen content and a significant progress in plasma insulin and C-peptide level. The distorted activities of key enzymes of glycolysis, TCA cycle, HMP shunt, gluconeogenesis, and glycogen metabolism such as glycogenesis and glycogenolysis pathways observed in liver and kidney tissues of diabetic rats were significantly reverted to near normalcy by the oral administration of MFE. Further, the results were compared with gliclazide, an oral standard drug. Conclusion: The results of the current study indicate that this fruit plays an indispensable character in regulating key enzymes of glucose synthesis and utilization reactions to sustain normoglycemia. Moreover consumption of Mengkudu fruit is nontoxic to the system and is hepatoprotective. Presence of biologically active ingredients such as alka- loids, flavonoids, triterpenoids, minerals, and vitamins presumed to account for the anti- hyperglycemic properties of M. citrifolia fruits. Copyright ª 2013, JPR Solutions; Published by Reed Elsevier India Pvt. Ltd. All rights reserved. * Corresponding author. Tel.: þ60 09 6275680, þ60 11 16547654 (mobile); fax: þ60 09 6275583. E-mail addresses: raousm@gmail.com, raousm@unisza.edu.my, raobioresearch@gmail.com (U.S.M. Rao). Available online at www.sciencedirect.com journal homepage: www.elsevier.com/locate/jopr journal of pharmacy research 7 (2013) 53 e61 0974-6943/$ e see front matter Copyright ª 2013, JPR Solutions; Published by Reed Elsevier India Pvt. Ltd. All rights reserved. http://dx.doi.org/10.1016/j.jopr.2013.01.003