Regulatory Effects of Solvent-partitioned Fractions of Cola acuminata Seed on Glucose Metabolism in Streptozotocin-induced Diabetic Rats

Abstract

Introduction: Diabetes mellitus, a metabolism disorder symptomized by high concentration of fasting blood glucose, poses major health challenge. Aims: This research aimed at assessing antihyperglycemic potentials of n-hexane-partitioned (NHF), n-butanol-partitioned (NBF), ethyl acetate-partitioned (ETHF) and residual-partitioned fractions of Cola acuminata seed in streptozotocin-induced diabetic rats. Effects of these solvent-partitioned fractions were assessed on fasting blood glucose (FBS), serum insulin (SI) and hepatic glycogen (HG) concentration. Also, on activities of hexokinase (HK), glucose-6-phosphate dehydrogenase (G6PDH), glucose-6-phospatase (G6Pase), fructose-1,6-bisphosphatase (F16BPase) and glycogen phosphorylase GPase). Study design: Experimental design was completely randomized design and analysis of variance was used to process data with the aid of GraphPad Prism version 6.0. Methodology: 35 male, non-diabetic albino rats (weights between 120g – 150g) were randomly divided into 7 seven groups. Rats were induced with diabetes using streptozotocin except control group.  Diabetic groups were administered distilled water, metformin, NHF, ETHF, NBF and residual-partitioned fraction (RF) of Cola acuminata seed respectively. Effects of these treatments were assessed on FBS, SI and HG concentrations of streptozotocin-induced diabetic rats after 15-day experimental period. Also, activities of HK, G6PDH, G6Pase, F16BPase and GPase were determined. Results: NHF, ETHF, NBF and RF of Cola acuminata seed significantly alleviate (P < .05) increased FBS concentration (from 30.73± 0.52 to 4.73± 0.34 mmol/L) and activities of G6Pase, F16Bpase and GPase (from 13.05 to 7.56; 13.72 to 9.09 and 8.96 to 3.33 U/L/mg protein respectively) while decreased concentration of SI and HG; activities of hepatic HK, G6PDH were notably increased (P < .05) (from 1.57 to 3.20 mg/ml; 35.42 to 73.74 mg/dl; 0.64 to 1.42 mmol/min/mg protein; 1.51 to 2.26 U/L/mg protein).     Conclusion: The study concluded that these solvent-partitioned fractions of Cola acuminata seed shows modulatory potentials on some glucose-metabolizing parameters via inhibition and stimulation of their activities and concentration.