e n v i r o n m e n t a l t o x i c o l o g y a n d p h a r m a c o l o g y 3 7 ( 2 0 1 4 ) 326–335 Available online at www.sciencedirect.com ScienceDirect j o ur nal ho me pa ge: www.elsevier.com/locate/etap Modulatory effects of morin on hyperglycemia by attenuating the hepatic key enzymes of carbohydrate metabolism and -cell function in streptozotocin-induced diabetic rats P. Vanitha a , C. Uma a , N. Suganya a , E. Bhakkiyalakshmi a , S. Suriyanarayanan b , P. Gunasekaran c , S. Sivasubramanian c , K.M. Ramkumar d,∗ a Department of Biotechnology, School of Bioengineering, SRM University, Kattankulathur 603 203, Tamilnadu, India b Department of Water and Health, JSS University, Mysore 570 015, Karnataka, India c The King Institute of Preventive Medicine and Research, Guindy, Chennai 600 032, Tamilnadu, India d SRM Research Institute, SRM University, Kattankulathur 603 203, Tamilnadu, India a r t i c l e i n f o Article history: Received 23 August 2013 Received in revised form 18 November 2013 Accepted 19 November 2013 Available online 9 December 2013 Keywords: Morin Antidiabetic activity STZ Carbohydrate enzymes Natural products a b s t r a c t The present study was aimed to evaluate the effect of morin on blood glucose, insulin level, hepatic glucose regulating enzyme activities and glycogen level in experimental diabetes. Diabetes mellitus was induced by a single intraperitoneal injection of streptozotocin (STZ) (50 mg/kg b.w.). Five days after STZ injection, diabetic rats received morin (25 and 50 mg/kg b.w.) orally for 30 days. Glibenclamide was used as reference drug. Morin treatment sig- nificantly reduced the blood glucose and improved the serum insulin levels. Further, a dose-dependent reduction in glucose-6-phosphatase and fructose-1,6-bisphosphatase was observed along with the increase in liver hexokinase and glucose-6-phosphate dehydro- genase activities. Morin supplement were found to be effective in preserving the normal histological appearance of pancreatic islets as well as to preserve insulin-positive -cells in STZ-rats. Therefore, these findings suggest that morin displays beneficial effects in the treatment of diabetes, mediated through the regulation of carbohydrate metabolic enzyme activities. © 2013 Elsevier B.V. All rights reserved. 1. Introduction Diabetes is a group of metabolic diseases characterized by hyperglycemia resulting from impaired glucose homeostasis and insulin action. In the 2011, 5th edition of the Diabetes Atlas, the estimates were of 366 million people worldwide with diabetes for 2011, and an anticipated 551 million for 2030 ∗ Corresponding author at: SRM Research Institute, SRM University, Kattankulathur 603 203, Tamilnadu, India. Tel.: +91 9940737854; fax: +91 44 2745 2343. E-mail addresses: ramkumar.km@res.srmuniv.ac.in, ramkumarbiotech@gmail.com (K.M. Ramkumar). (Whiting et al., 2011). Due to the side effects associated with the antihyperglycemic agents for the treatment of diabetes, currently there is growing interest in plants and plant derived products (Grover et al., 2002). The World Health Organiza- tion expert committee is also considering complementary and alternative approaches, including the use of herbal medicine with antidiabetic properties due to their natural origin and less side effects (Modak et al., 2007). 1382-6689/$ – see front matter © 2013 Elsevier B.V. All rights reserved. http://dx.doi.org/10.1016/j.etap.2013.11.017