Chlorophytum borivilianum root extract maintains near normal blood glucose, insulin and lipid profile levels and prevents oxidative stress in the pancreas of streptozotocin-induced adult male diabetic rats

Abstract

The effect of C. borivilianum root on blood glucose, glycated hemoglobin (HbAIc), insulin and lipid profile levels in diabetes mellitus are not fully understood. This study therefore investigated the effect of C. borivilianum root on the above parameters and oxidative stress of the pancreas in diabetes.

Methods: C. borivilianum root aqueous extract (250 and 500 mg/kg/day) was administered to streptozotocin (STZ)-induced male diabetic rats for 28 days. Body weight, blood glucose, HbA1c, insulin, lipid profile levels and glucose homeostasis indices were determined. Histopathological changes and oxidative stress parameters i.e. lipid peroxidation (LPO) and antioxidant enzymes activity levels of the pancreas were investigated.

Results: C. borivilianum root extract treatment to diabetic rats maintained near normal body weight, blood glucose, HbA1c, lipid profile and insulin levels with higher HOMA-β cell functioning index, number of Islets/pancreas, number of β-cells/Islets however with lower HOMA-insulin resistance (IR) index as compared to non-treated diabetic rats. Negative correlations between serum insulin and blood glucose, HbA1c, triglyceride (TG) and total cholesterol (TC) levels were observed. C. borivilianum root extract administration prevented the increase in lipid peroxidation and the decrease in activity levels of superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx) with mild histopathological changes in the pancreas of diabetic rats.

Conclusions: C. borivilianum root maintains near normal levels of these metabolites and prevented oxidative stress-induced damage to the pancreas in diabetes.

Keywords: Chlorophytum borivilianum; diabetes; glucose; lipid profile; oxidative stress.; pancreas.

Figure 1

Effect of C. borivilianum root aqueous extract treatment on initial and final body weight in different experimental groups. Significantly lower body weight was noted in diabetic rats as compared to normal, non-diabetic rats. C. borivilianum root aqueous extract and glibenclamide treatments prevented body weight loss in diabetic rats. n=6 rats per group. *p<0.05 as compared to initial body weight. 250C: 250mg/kg/day C. borivilianum root aqueous extract, 500C: 500mg/kg/day C. borivilianum root aqueous extract; 600G: 600µg/kg/day glibenclamide.

Figure 2

Effect of C. borivilianum root aqueous extract treatment on the FBG level at weekly interval in different experimental groups within 28-days of treatment. No significant changes in FBG level were noted in normal, non-diabetic rats. In diabetic rats, FBG was persistently high throughout 28 days. A significantly lower FBG level was noted beginning from day 7 of C. borivilianum root aqueous extract and glibenclamide treatments. Near normal FBG was observed in these treatment groups at day 28. n=6 rats per group. 250C: 250mg/kg/day C. borivilianum root aqueous extract, 500C: 500mg/kg/day C. borivilianum root aqueous extract; 600G: 600µg/kg/day glibenclamide.

Figure 3

A) Effect of C. borivilianum root aqueous extract treatment on HbA1c level in different experimental groups. The level of HbA1c was the highest in diabetic group. Treatment with C. borivilianum root aqueous extract or glibenclamide caused significantly lower HbA1c levels as compared to the non-treated diabetic rats. n=6 rats per treatment group. *p<0.05 as compared to normal, non-diabetic rats. †P<0.05 as compared to non-treated diabetic rats. 250C: 250mg/kg/day C. borivilianum root aqueous extract, 500C: 500mg/kg/day C. borivilianum root aqueous extract; 600G: 600µg/kg/day glibenclamide. B) Effect of C. borivilianum root aqueous extract treatment on serum insulin levels in different experimental groups. The level of insulin is the lowest in diabetic rats. Treatment with C. borivilianum root aqueous extract or glibenclamide caused significantly higher serum insulin levels as compared to the non-treated diabetic rats. n=6 rats per treatment group. *p<0.05 as compared to normal, non-diabetic rats. †P<0.05 as compared to non-treated diabetic rats. 250C: 250mg/kg/day C. borivilianum root aqueous extract, 500C: 500mg/kg/day C. borivilianum root aqueous extract; 600G: 600µg/kg/day glibenclamide.

Figure 4

Correlation between serum insulin levels and (a) blood glucose levels at day 28, (b) HbA1c, (c) triglyceride and (d) total cholesterol levels. There are strong negative correlations (r>0.90) between serum insulin levels and the studied parameters indicating insulin-dependent changes.

Figure 5

Representative high magnification image of pancreas in different experimental groups. A) normal, non-diabetic rats, B) STZ-induced diabetic rats, C) 250mg/kg/day C. borivilianum root aqueous extract treatment, D) 500mg/kg/day C. borivilianum root aqueous extract treatment and E) glibenclamide treatment. Lower number and size of Islets of Langerhans was observed in diabetic rats as compared to non-diabetic rats. C. borivilianum root aqueous extract treatment caused higher Islet size and numbers in diabetic rats. IrD - Interlobular duct, CT - Connective tissue, BV- Blood vessel, IL - Islet of Langerhans. Scale bar = 50µm.

Figure 6

A) Estimation of LPO product, MDA in pancreas in different experimental groups. Higher MDA levels were noted in diabetic rats as compared to normal, non-diabetic rats. Administration of C. borivilianum root extract resulted in decreased MDA levels. B) SOD activity levels in pancreas in different experimental groups. SOD activity was reduced in diabetic rats as compared to normal, non-diabetic rats. Administration of C. borivilianum root extract at 250 and 500mg/kg/day or glibenclamide in diabetic rats resulted in higher SOD activity levels as compared to non-treated diabetic rats. C) CAT activity levels in pancreas in different experimental groups. Administration of C. borivilianum root extract at 250 and 500mg/kg/day or glibenclamide in diabetic rats prevented the deterioration in CAT activity levels. D) GPx activity levels in pancreas in different experimental groups. Administration of C. borivilianum root extract at 250 and 500mg/kg/day or glibenclamide prevented the deterioration of GPx activity in diabetes. 250C: 250 mg/kg/day C. borivilianum root extract; 500C: 500 mg/kg/day C. borivilianum root extract, 600G: 600 µg/kg/day glibenclamide. n=6 per treatment group, *p<0.05 as compared to normal, non-diabetic control rats, †p<0.05 as compared to non-treated diabetic rats.