Gluconeogenic Substrates and Hepatic Gluconeogenic Enzymes in Streptozotocin-Diabetic Rats: Effect of Mulberry (Morus indica L.) Leaves

2007 ◽  
Vol 10 (1) ◽  
pp. 41-48 ◽  
Author(s):  
B. Andallu ◽  
N.C. Varadacharyulu
1993 ◽  
Vol 292 (1) ◽  
pp. 267-270 ◽  
Author(s):  
B A Shibib ◽  
L A Khan ◽  
R Rahman

Coccinia indica leaves were extracted with 60% ethanol, solvents were evaporated and the residue was suspended in water. This suspension was administered orally at a dose of 200 mg/kg body wt. after 18 h of fasting to normal fed and streptozotocin-induced male diabetic rats (180-250 g). After 90 min the rats were killed, and blood-glucose, hepatic glucose-6-phosphatase, fructose-1,6-bisphosphatase and glucose-6-phosphate dehydrogenase (G6PDH) and red-cell G6PDH were assayed. Blood sugar was depressed by 23% (P < 0.01) and 27% (P < 0.001) in the normal fed and streptozotocin-diabetic rats respectively compared with controls which were given distilled water. Hepatic glucose-6-phosphatase and fructose-1,6-bisphosphatase activities were depressed by 32% (P < 0.001) 30% (P < 0.05) respectively in the streptozotocin-diabetic rats, compared with 19% (P < 0.02) and 20% (P < 0.01) depression in the normal fed controls, whereas both the red-cell and hepatic G6PDH activities were found to be elevated by feeding the extract in the streptozotocin-diabetic and in the normal fed controls. Similar results were obtained with the 95%-ethanolic extract of Momordica charantia. Taken together, these results indicate that Coccinia indica and Momordica charantia extracts lowered blood glucose by depressing its synthesis, on the one hand through depression of the key gluconeogenic enzymes glucose-6-phosphatase and fructose-1,6-bisphosphatase and on the other by enhancing glucose oxidation by the shunt pathway through activation of its principal enzyme G6PDH.


1991 ◽  
Vol 266 (14) ◽  
pp. 8671-8674
Author(s):  
E. Unger ◽  
I. Pettersson ◽  
U.J. Eriksson ◽  
U. Lindahl ◽  
L. Kjellén

2002 ◽  
Vol 3 (2) ◽  
pp. 119-130 ◽  
Author(s):  
Fulya Zobali ◽  
Tanju Besler ◽  
Nuray Ari ◽  
Çimen Karasu

A positive correlation has been established between increased oxidative stress and cardiovascular diseases in diabetes mellitus. We evaluated the effects of single or combined treatments with vitamin A (retinol acetate, 30 mg/kg/day, for 12-weeks) and insulin (8-10 IU/rat/day for the final 6-week) on vasomotor activity, oxidative stress and retinol metabolism in 12-week streptozotocin diabetic rats. The vasomotor activity was determined by measuring invitroresponsiveness of aorta rings to phenylephrine (PE) and acetylcholine (ACh) in the absence or in the presence of hydrogen peroxide (H2O2). Preincubation withH2O2(10 μM) produced a significant decrease in PE (1 mM)-induced contraction in untreated-diabetic but not in control rats. Single treatment with insulin counteracted this effect ofH2O2and also reversed the increased contractile response of diabetic aorta to PE, while vitamin A was found to be ineffective.H2O2(10 μM) also inhibited ACh (1 mM)-stimulated endothelium- dependent relaxation two fold more in diabetic than in control aorta. In the prevention ofH2O2-induced inhibition of vascular relaxation to ACh, vitamin A alone was markedly effective while insulin alone was not. The combination of vitamin A plus insulin removed the inhibitory action ofH2O2in diabetic aorta. Diabetic animals displayed an increased level of aorta thiobarbituric acid reactive substance (TBARS) in association with decreased levels of plasma retinol and retinol-binding protein (RBP). Single treatment with insulin, in spite of allowing recovery of normal growth rate and improved glucose and retinol metabolism in diabetic rats, was unable to control TBARS production to the same extent as vitamin A alone. Our findings suggest that the maintenance of ACh-stimulated endothelium-dependent vasorelaxant tone in normal physiological levels depends largely on the prevention and/or inhibition of peroxidative stress, which is achieved by combined treatment with vitamin A plus insulin. The use of vitamin A together with insulin provides a better metabolic control and more benefits than use of insulin alone in the reduction of diabetes-induced vascular complications.


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