Effect Of Aegle Marmelos Correa On Blood Glucose Level In Normal And Alloxan- Induced Diabetic Albino Rats
S Baishnab, S Das
Keywords
alloxan, antihyperglycemic effect, aqueous extract, diabetes mellitus
Citation
S Baishnab, S Das. Effect Of Aegle Marmelos Correa On Blood Glucose Level In Normal And Alloxan- Induced Diabetic Albino Rats. The Internet Journal of Pharmacology. 2012 Volume 10 Number 1.
Abstract
The aim of the present study is to evaluate the action extract of
Introduction
Diabetes mellitus (DM) refers to a group of common metabolic disorders that share the phenotype of hyperglycemia1. A changing lifestyle in developing countries like India has enormously increased the statistical figures of diabetes mellitus. A survey depicts that 4% of adults in India suffered from DM in year 20000 and it is expected to increase by 6% by the year 2025.2
Materials and Methods
Plant material and extraction
The fruit pulp of
The fruit pulp of
Animals
Healthy adult Wistar albino rats
Chemicals used
Crude powder of glibenclamide was obtained from Sun Pharma Ltd., mumbai while alloxan monohydrate was purchased from Sigma Aldrich India, Bangalore. The glucose kit for blood glucose estimation was obtained from Sigma Diagnostic (India) Pvt. Ltd., Baroda.
Experimental design for antidiabetic study
A total of thirty animals were equally divided into five groups with six animals in each group:
Group–A : Normal Control. Received normal saline, 2 ml/kg/d. Group- B: Normal Test. Received normal saline, 2 ml/kg/d. Group–C: Diabetic Control. Received normal saline, 2 ml/kg/d. Group–D: Diabetic Test. Received aqueous extract of
The above drugs were administered orally, once daily, for four weeks.
Induction of diabetes
Leaving aside six rats for Normal Control Group, 24 rats were induced diabetes by a single intraperitoneal injection of alloxan monohydrate in the dose of 150 mg/kg body weight. The fasting blood glucose was determined after 72 hours. 18 rats showing blood glucose level greater than 200 mg/100 ml were taken for the study. 8
Blood glucose was estimated every week for four consecutive weeks. Blood glucose estimation was done by glucose oxidase method. 9
Probable mechanism of antidiabetic action
Glycogen estimation of liver, skeletal muscle and cardiac muscle.
Out of 30 rats, 24 rats were induced diabetes by alloxan monohydrate (150 mg/kg body weight) intraperitoneally and 18 rats with blood glucose level greater than 200 mg/100ml were taken after 72 hours of diabetes induction. All the rats were kept fasting for 18 hours before the experiment. The rats were divided into four groups with six animals in each, as before.
Group–A: Normal Control. Received normal saline, 2 ml/kg/d. |Group–B: Diabetic Control. Received normal saline,2 ml/kg/d and alloxan. Group–C: Diabetic Test. Received AEAM, 100 mg/kg/d and alloxan. Group–D: Diabetic Standard. Received glibenclamide, 0.5 mg/kg/d and alloxan.
After two hours of administration of above drugs. The animals were killed by decapitation. The liver, leg muscle and heart tissues were taken out with care and their glycogen content was estimated by use of Anthrone reagent.
Effect on adrenaline-induced hyperglycemia
The rats were divided into three groups with six animals in each as before.
Group–A : Normal Control. Received normal saline, 2 ml/kg/d. Group–B: Test Drug. Received AEAM, 100 mg/kg/d. Group–C: Standard Drug. Received glibenclamide, 0.5 mg/kg/d.
The above drugs were administered orally after drawing fasting blood samples. Adrenaline hydrochloride 100 µg was administered intraperitoneally to all the rats one hour after drug administration. Blood samples were again collected half an hour.
Statistical analysis
The data was statistically analysed using One-way ANOVA 12 followed by Dunnett’s multiple comparison test 13 .Values of
Results
Effect on blood glucose level
The data was statistically analysed using One-way ANOVA followed by Dunnett’s multiple comparison test.
Normal Rats: No significant (
Diabetic Rats
Values are expressed as Mean ± SEM; n=6 rats in each group. One-way ANOVA followed by Dunnett’s multiple comparison tests was done. *p<0.01 when compared to Normal Control Group. * p<0.01when compared to Diabetic Control Group.
Figure 1
Effect on glycogen estimation
The data was statistically analysed using One-way ANOVA followed by Dunnett’s multiple comparison test.
There was a significant (
Values are expressed as Mean ± SEM; n=6 rats in each group. One-way ANOVA followed by Dunnett’s multiple comparison tests was done. *p <0.01when compared to Diabetic Control Group.
Figure 2
Effect on adrenaline-induced hyperglycemia
The test drug and the standard drug significantly (
Values are expressed as Mean ± SEM; n=6 rats in each group. One-way ANOVA followed by Dunnett’s multiple comparison tests was done. *p <0.01when compared to Diabetic Control Group.
Figure 3
Discussion
From the study, it was seen that AEAM significantly (
Alloxan, a β-cytotoxic agent, rapidly and selectively accumulates in pancreatic β-cells and causes β-cell death and apoptosis by generation of reactive oxygen species (ROS), superoxide radicals and hydrogen peroxide. 15,16 β cell death causes hyperglycemia due to insulin deficiency which further aggravates the oxidative stress induced by alloxan.17
The antidiabetic activity of the fruit pulp of
Insulin is a potent activator of the enzyme glycogen synthase while inhibiting the enzyme glycogen phosphorylase responsible for glycogenolysis in liver and muscle.22 Insulin deficiency in diabetes, as such, results in reduced concentrations of glycogen in liver and muscle. AEAM caused an increase in glycogen concentration of the liver probably by stimulating the enzymes glycogen synthase and hexokinase, both of which contribute to increase glycogen synthesis.23 The increase in liver glycogen may also have been brought about by inhibition of the enzyme glucose-6-phosphatase leading to accumulation of glucose-6-phosphate, which allosterically inhibited the enzyme glycogen phosphorylase.24 Diminished phosphatidylinositol 3-kinase (PI-3K) activation in diabetes as a result of insulin deficiency has been reported to be associated with impaired skeletal muscle glycogen synthase enzyme.25 AEAM due to the insulin-like action of its ingredients probably increased PI-3K activation leading to stimulation of muscle glycogen synthase. The increased concentration of glycogen in skeletal and cardiac muscle also might be due to increased expression and translocation of GLUT-4 glucose transporters as a result of increased PI-3K activation, leading to increased peripheral uptake of glucose .26
Adrenaline produces hyperglycemia by inhibiting insulin release, stimulating glycogenolysis in muscle and thus providing substrate in the form of lactate for hepatic gluconeogenesis, stimulating glucagon secretion and stimulating ACTH secretion which, in turn, stimulates glucocorticoid secretion from the adrenal cortex. 27 It has also been reported that adrenaline produces hyperglycemia by increasing glucose uptake from both the large and small intestine.28 The test drug significantly (p<0.01) reduced the adrenaline induced hyperglycemia probably by inhibiting adrenaline induced stimulation of α2 receptors in β-cells of pancreas and thus promoting further insulin release.29
Conclusion
Thus, the hypoglycemic and antidiabetic effect of AEAM may be partly due to its positive effect on glycogen synthesis in liver, skeletal muscle and heart muscle due to the insulin-like action of its constituents, and partly due to the stimulatory action on insulin release by blocking the α2 receptors in β-cells of pancreas. However, further studies to isolate the active principle of