Actions Underlying Antidiabetic Effects of Ocimum sanctum Leaf Extracts in Animal Models of Type 1 and Type 2 Diabetes
J. M. A. Hannan
Department of Pharmacy, North South University, Dhaka, Bangladesh
O. O. Ojo *
School of Biomedical Sciences, University of Ulster, Coleraine, Northern Ireland, BT52 1SA, United Kingdom and Chevron Biotechnology Centre, Modibbo Adama University of Technology, Yola, Nigeria
L. Ali
Research Division, BIRDEM, Dhaka, Bangladesh
B. Rokeya
Research Division, BIRDEM, Dhaka, Bangladesh
J. Khaleque
Department of Pharmacy, North South University, Dhaka, Bangladesh
M. Akhter
Research Division, BIRDEM, Dhaka, Bangladesh
P. R. Flatt
School of Biomedical Sciences, University of Ulster, Coleraine, Northern Ireland, BT52 1SA, United Kingdom
Y. H. A. Abdel-Wahab
School of Biomedical Sciences, University of Ulster, Coleraine, Northern Ireland, BT52 1SA, United Kingdom
*Author to whom correspondence should be addressed.
Abstract
Aim: This study investigated mechanisms by which O. sanctum leaf extracts ameliorate hyperglycaemia using animal and cellular models of diabetes.
Place and Duration of Study: Diabetes Research Laboratory, University of Ulster, Coleraine, United Kingdom and Research Division, BIRDEM, Dhaka, Bangladesh; 8 months.
Methodology: Acute anti-diabetic effects of ethanolic extracts of O. sanctum were examined in normal and chemically-induced type 1 and 2 diabetic rats. Effects of extracts on glucose absorption, intestinal disaccharidase activity and gastrointestinal motility in type 2 diabetic rats and on glucose uptake and insulin action in 3T3-L1 cells were assessed.
Results: Treatment with the extract (1.25 g/kg bw) significantly improved oral glucose tolerance in normal and type 2 diabetic rats and suppressed blood glucose elevation after oral sucrose (2.5 g/kg bw) administration. The extract significantly reduced glucose absorption, gastrointestinal motility and disaccharidase activity. A 28-day treatment with O. sanctum decreased serum glucose, increased liver glycogen and enhanced circulating insulin and total oxidant status in type 2 diabetic rats. Glucose transport and insulin action in 3T3-L1 were increased by extract.
Conclusion: O. sanctum represents a useful as a source for discovery of novel antidiabetic compounds and as a dietary adjunct for the management of type 2 diabetes and its complications.
Keywords: Ocimum sanctum, 3T3 adipocytes, intestinal disaccharidase activity, hepatic glycogen, glucose uptake