The influence of rutin on the extracellular matrix in streptozotocin-induced diabetic rat kidney.

We previously reported that rutin administration to streptozotocin (STZ)-induced diabetic rats decreased plasma glucose and increased plasma insulin levels. In this study, we have examined the role of rutin on matrix remodelling in the kidney of STZ-induced diabetic rats. STZ was administered intraperitoneally (50 mg kg(-1)) to male albino Wistar rats to induce experimental diabetes. Rutin (100 mg kg(-1)) was orally administered to normal and STZ-induced diabetic rats for a period of 45 days and its influence on the content of hydroxyproline and collagen and on the activity of matrix metalloproteinases (MMPs) were studied. We have also studied the levels of tissue inhibitors of metalloproteinases (TIMPs) in the kidney. STZ-induced diabetic control rats showed increased content of hydroxyproline and collagen, decreased activity of MMPs and increased levels of TIMPs in the kidney. These changes were positively modulated by rutin treatment in STZ-induced diabetic rats, thereby protecting the kidney. In normal rats treated with rutin, none of the parameters studied were significantly altered. From the results obtained, we could conclude that rutin influences MMPs and effectively protects kidney against STZ-induced damage in rats. The effects observed are due to the reduction of plasma glucose levels by rutin.

Rutin improves the antioxidant status in streptozotocin-induced diabetic rat tissues.

Rutin, a polyphenolic flavonoid, was investigated for its antioxidant potential in streptozotocin (STZ)-induced diabetic rats. Rats were rendered diabetic by a single intraperitoneal injection of streptozotocin (50 mg/kg). The levels of fasting plasma glucose and insulin were estimated. Lipid peroxidative products and antioxidants were estimated in liver, kidney and brain. Histopathological studies were carried out in these tissues. A significant (p < 0.05) increase in the levels of fasting plasma glucose, lipid peroxidative products (thiobarbituric acid reactive substances [TBARS] and lipid hydroperoxides [HP]) and a significant (p < 0.05) decrease in plasma insulin, enzymic antioxidants (superoxide dismutase [SOD], catalase, glutathione peroxidase [GPx] and glutathione reductase [GRx]) and nonenzymic antioxidants (reduced glutathione [GSH], vitamin C and E) in diabetic liver, kidney and brain were observed. Oral administration of rutin (100 mg/kg) for a period of 45 days significantly (p < 0.05) decreased fasting plasma glucose, increased insulin levels and improved the antioxidant status of diabetic rats by decreasing lipid peroxidative products and increasing enzymic and nonenzymic antioxidants. Normal rats treated with rutin (100 mg/kg) showed no significant (p < 0.05) effect on any of the parameters studied. Histopathological studies of the liver, kidney and brain showed the protective role of rutin. Thus, our study clearly shows that rutin has antioxidant effect in STZ-induced experimental diabetes.

Rutin improves glucose homeostasis in streptozotocin diabetic tissues by altering glycolytic and gluconeogenic enzymes.

The role of rutin on carbohydrate metabolism in normal and streptozotocin (STZ)-induced diabetic rats was investigated in the present study. Administration of STZ led to a significant (p <0.05) increase in fasting plasma glucose and a decrease in insulin levels. The content of glycogen significantly (p <0.05) decreased in liver and muscle, but increased in kidney. The activity of hexokinase decreased whereas the activities of glucose-6-phosphatase and fructose-1,6-bisphosphatase significantly (p <0.05) increased in the tissues. Oral administration of rutin (100 mg/kg) to diabetic rats for a period of 45 days resulted in significant (p <0.05) alterations in the parameters studied but not in normal rats. A decrease of plasma glucose and increase in insulin levels were observed along with the restoration of glycogen content and the activities of carbohydrate metabolic enzymes in rutin-treated diabetic rats. The histopathological study of the pancreas revealed the protective role of rutin. There was an expansion of the islets and decreased fatty infiltrate of the islets in rutin-treated diabetic rats. In normal rats treated with rutin, we could not observe any significant change in all the parameters studied. Combined, these results show that rutin plays a positive role in carbohydrate metabolism and antioxidant status in diabetic rats.

The effect of Aegle marmelos fruit extract in streptozotocin diabetes: a histopathological study.

Aegle marmelos Correa. (Bael) fruit exhibit antidiabetic, antihyperlipidaemic and antioxidant properties. This study was designed to elucidate the protective effect of an aqueous extract of Aegle marmelos fruits on the histopathology of the pancreas in streptozotocin-induced diabetic rats. Oral administration of Aegle marmelos fruit extract at doses of 125 and 250 mg/kg twice daily to diabetic rats for a period of 30 days resulted in a significant increase in body weight, weight of the pancreas and insulin levels associated with a significant decrease in fasting blood glucose levels. The fruit extract treated groups showed improved functional state of the pancreatic ss-cells and partially reversed the damage caused by streptozotocin to the pancreatic islets. The findings of our study indicate that Aegle marmelos fruit extract exhibits protective effects on the pancreas. The effects observed in the fruit extract treated animals were better those in animals treated with glibenclamide (300 microg/kg).

Antidiabetic and antihyperlipidaemic effect of alcoholic Syzigium cumini seeds in alloxan induced diabetic albino rats.

Syzigium cumini, commonly known as 'jamun', is widely used in different parts of India for the treatment of diabetes mellitus. The present study was designed to evaluate the antidiabetic and antihyperlipidaemic effect of an alcoholic extract of Syzigium cumini seeds (JSEt) in alloxan diabetic rats. Diabetes was induced by single intraperitoneal injection of alloxan (150 mg kg(-1) body weight). Oral administration of alcoholic JSEt to diabetic rats at a dose of 100 mg kg(-1) body weight resulted in a significant reduction in blood glucose and urine sugar and lipids in serum and tissues in alloxan diabetic rats. The extract also increases total haemoglobin. The extract brought back all the parameters to normal levels. The effect of alcoholic JSEt was similar to that of insulin. Thus, our investigation clearly shows that alcoholic JSEt has both antidiabetic and antihyperlipidaemic effects.

Supplementation of fenugreek leaves to diabetic rats. Effect on carbohydrate metabolic enzymes in diabetic liver and kidney.

The present study was designed to evaluate the effect of supplementation of fenugreek leaves, an indigenous plant widely used in Indian Ayurvedic medicine for the treatment of diabetes mellitus, in streptozotocin induced diabetic rats. Supplementation of the diet with fenugreek leaves showed a significant effect on hyperglycaemia, hypoinsulinaemia and glycosylated haemoglobin in streptozotocin diabetic rats. Fenugreek leaves improved the body weight and liver glycogen. Fenugreek leaves also showed a significant effect on key carbohydrate metabolic enzymes in diabetic rats. The effect of fenugreek leaves was found to be similar to that of glibenclamide. Thus, fenugreek leaves exhibited antidiabetic action in streptozotocin-induced diabetic rats. Insulin restored all the parameters to near normal levels in diabetic rats.

Hypoglycaemic effect of water extracts of Aegle marmelos fruits in streptozotocin diabetic rats.

Aegle marmelos Corr. (Rutaceae) is widely used in Indian Ayurvedic medicine for the treatment of diabetes mellitus. The hypoglycaemic effect of the water extract of the fruits of Aegle marmelos was examined in streptozotocin-induced diabetic Wistar rats. Oral administration of the water extract (125 and 250mgkg(-1)) twice a day for 4 weeks resulted in significant reductions in blood glucose, plasma thiobarbituric acid reactive substances, hydroperoxides, ceruloplasmin and alpha-tocopherol and a significant elevation in plasma reduced glutathione and Vitamin C in diabetic rats. The effect of the extract at a dose of 250mgkg(-1) was more effective than glibenclamide in restoring the values of these parameters. The results of this study clearly shows the hypoglycaemic activity of the fruit extract.

Syzigium cumini seed extracts reduce tissue damage in diabetic rat brain.

Syzigium cumini commonly known as Jamun, is widely used in different parts of India for the treatment of diabetes mellitus. Oral administration of an aqueous Jamun seed extract (JSEt) for 6 weeks caused a significant decrease in lipids, thiobarbituric acid reactive substances (TBARS) and an increase in catalase and superoxide dismutase in the brain of alloxan induced diabetic rats. Oral administration of an alcoholic JSEt for 6 weeks brought back all the parameters to near normal. The effect of alcoholic JSEt (100 mg/kg) was better than aqueous JSEt (5 g/kg). The effect of both these extracts was better than glibenclamide (600 microg/kg). Thus, our study shows that S. cumini seed extracts reduce tissue damage in diabetic rat brain.

Effect of Aegle marmelos Correa. (Bael) fruit extract on tissue antioxidants in streptozotocin diabetic rats.

A study was undertaken to evaluate the anti-lipid peroxidative activity of an aqueous extract of A. marmelos fruits (AMFEt) in streptozotocin diabetic rats in heart and pancreas. Oral administration of AMFEt for 30 days (125 and 250 mg kg(-1) body weight twice daily) produced a significant decrease in the elevated levels of peroxidation products, viz. thiobarbituric acid reactive substances and hydroperoxides in the tissues of diabetic rats. The depressed activities of superoxide dismutase, catalase and glutathione peroxidase and lowered glutathione content in the heart and pancreas of diabetic rats were found to increase on treatment with AMFEt. AMFEt at a dose of 250 mg kg(-1) was more effective than glibenclamide (300 microg kg(-1)) and both reversed all the values significantly. Thus AMFEt exhibits anti-oxidative activity in streptozotocin diabetic rats.