Showing papers by "Leelavinothan Pari published in 2005"

Protective role of tetrahydrocurcumin (THC) an active principle of turmeric on chloroquine induced hepatotoxicity in rats.

Abstract: PURPOSE. Tetrahydrocurcumin (THC) is an antioxidative substance, which is derived from cur- cumin, the component of turmeric. In the present investigation, the effect of THC and curcumin against chloroquine (CQ) induced hepatotoxicity were studied in female Wistar rats. METHODS On single oral administration of CQ (970 mg/kg body weight) the activities of serum marker enzymes namely aspartate transaminase, alanine transaminase and alkaline phos- phatase and the levels of bilirubin were significantly increased with significant alterations of lipids in serum and lipidperoxidation markers such as thiobarbituric acid reactive substances (TBARS) and hydroperoxides in plasma and liver were also elevated in CQ treated rats. The levels of non-enzymic antioxidants (vitamin C, vitamin E and reduced glutathione) and enzymic antioxidants (superoxide dismutase, catalase and glu- tathione peroxidase) were also decreased in CQ treated rats. Administration of THC (80 mg/kg body weight) and curcumin (80 mg/kg body weight) for 8 days before and 7 days after single administration of CQ sig- nificantly decreased the activities of serum markers and lipids in serum. In addition, the level of TBARS and hydroperoxides were significantly decreased with sig- nificant increase in non-enzymic and enzymic antioxi- dants on treatment with THC and curcumin. The biochemical observation was supplemented by histo- pathological examination of liver section. The results of the study reveal that THC shows more pronounced protective effect than curcumin against CQ induced toxicity.

Antihyperlipidemic and antiperoxidative effect of Diasulin, a polyherbal formulation in alloxan induced hyperglycemic rats.

Abstract: This study was undertaken to investigation the effect of Diasulin, a poly herbal drug composed of ethanolic extract of ten medicinal plants on blood glucose, plasma insulin, tissue lipid profile, and lipidperoxidation in alloxan induced diabetes. Ethanolic extract of Diasulin a, poly herbal drug was administered orally (200 mg/kg body weight) for 30 days. The different doses of Diasulin on blood glucose and plasma insulin in diabetic rats were studied and the levels of lipid peroxides [TBARS, and Hydroperoxide] and tissue lipids [cholesterol, triglyceride, phospholipides and free fatty acids] were also estimated in alloxan induced diabetic rats. The effects were compared with glibenclamide. Treatment with Diasulin and glibenclamide resulted in a significant reduction of blood glucose and increase in plasma insulin. Diasulin also resulted in a significant decrease in tissue lipids and lipid peroxide formation. The effect produced by Diasulin was comparable with that of glibenclamide. The decreased lipid peroxides and tissue lipids clearly showed the antihyperlipidemic and antiperoxidative effect of Diasulin apart from its antidiabetic effect.

Antidiabetic effect of Scoparia dulcis: effect on lipid peroxidation in streptozotocin diabetes.

Abstract: Oxidative damage has been suggested to be a contributory factor in the development and complications of diabetes. The antioxidant effect of an aqueous extract of Scoparia dulcis, an indigenous plant used in Ayurvedic medicine in India was studied in rats with streptozotocin-induced diabetes. Oral administration of Scoparia dulcis plant extract (SPEt) (200 mg/kg body weight) for 3 weeks resulted in a significant reduction in blood glucose and an increase in plasma insulin. The aqueous extract also resulted in decreased free radical formation in tissues (liver and kidney) studied. The decrease in thiobarbituric acid reactive substances (TBARS) and hydroperoxides (HPX) and increase in the activities of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), reduced glutathione (GSH) and glutathione-S-transferase (GST) clearly show the antioxidant properties of SPEt in addition to its antidiabetic effect. The effect of SPEt at 200 mg/kg body weight was better than glibenclamide, a reference drug.

Effect of tetrahydrocurcumin on blood glucose, plasma insulin and hepatic key enzymes in streptozotocin induced diabetic rats

Abstract: The enzymes of glucose and lipid metabolism are markedly altered in experimental diabetes. In the present study, we investigated the effect of tetrahydrocurcumin (THC), one of the active metabolites in curcumin, on the key hepatic metabolic enzymes involved in carbohydrate metabolism in streptozotocin-induced diabetic rats. Different doses of THC (20, 40, and 80 mg\kg body weight) were orally administered to diabetic rats for 45 days. The activities of hexokinase, glucose-6-phosphate dehydrogenase (G6PD), glucose-6-phosphatase, fructose-1,6-bisphosphatase, and sorbitol dehydrogenase in liver, and glycogen content in liver and muscle were assayed. In untreated diabetic control rats, the activities of the gluconeogenic enzymes were significantly increased, whereas hexokinase and G6PD activity and glycogen levels were significantly decreased. Both THC and curcumin were able to restore the altered enzyme activities to near normal levels. Tetrahydrocurcumin was more effective than curcumin. Our results indicate that the administration of THC to diabetic animals normalizes blood glucose and causes a marked improvement of altered carbohydrate metabolic enzymes.

Modulation of impaired cholinesterase activity in experimental diabetes: effect of Gymnema montanum leaf extract.

Abstract: We reported that a leaf extract (GLEt) obtained from an anti-diabetic plant, Gymnema montanum, an endangered species endemic to India, has anti-peroxidative and antioxidant effects on diabetic brain tissue in rats. Here we examined the effect of the extract on the activity of reduced brain and retinal acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) in streptozotocin (STZ)-induced diabetic male Wistar rats. Diabetic rats received GLEt orally (200 mg/kg bwt/d) for 12 wk, and changes in blood glucose, plasma insulin, the lipid peroxidation marker thiobarbituric acid-reactive substance (TBARS), and AChE and BChE activity were measured. The results confirmed prior reports that hyperglycemia significantly enhances TBARS levels in brain and retinal tissue and decreases AChE and BChE activity. Treatment with GLEt significantly reversed the impairment in enzymatic activity in addition to reducing the level of TBARS, suggesting that GLEt protects against the adverse effect of lipid peroxidation on brain and retinal cholinesterases. We suggest that GLEt could be useful for preventing the cholinergic neural and retinal complications of hyperglycemia in diabetes.

Effect of an aqueous extract of Scoparia dulcis on plasma and tissue glycoproteins in streptozotocin induced diabetic rats.

Abstract: The influence of Scoparia dulcis, a traditionally used plant for the treatment of diabetes mellitus, was examined in streptozotocin diabetic rats on dearrangement in glycoprotein levels. Diabetes was induced in male Wistar rats by a single intraperitoneal injection of streptozotocin. An aqueous extract of Scoparia dulcis plant was administered orally for 6 weeks. The effect of the Scoparia dulcis extract on blood glucose, plasma insulin, plasma and tissue glycoproteins studied was in comparison to glibenclamide. The levels of blood glucose and plasma glycoproteins were increased significantly whereas the level of plasma insulin was significantly decreased in diabetic rats. There was a significant decrease in the level of sialic acid and elevated levels of hexose, hexosamine and fucose in the liver and kidney of streptozotocin diabetic rats. Oral administration of Scoparia dulcis plant extract (SPEt) to diabetic rats led to decreased levels of blood glucose and plasma glycoproteins. The levels of plasma insulin and tissue sialic acid were increased whereas the levels of tissue hexose, hexosamine and fucose were near normal. The present study indicates that Scoparia dulcis possesses a significant beneficial effect on glycoproteins in addition to its antidiabetic effect.

Succinic acid monoethyl ester and metformin regulates carbohydrate metabolic enzymes and improves glycemic control in streptozotocin-nicotinamide induced type 2 diabetic rats

Abstract: Objective. Succnic acid mono ethyl ester (EMS) was recently proposed as an insulinotropic agent for the treatment of non-insulin dependent diabetes mellitus. In the present study the effect of EMS and Metformin on the activities of carbohydrate metabolic enzymes in streptozotocin–nicotinamide induced type 2 diabeteic model was investigated. Methods. EMS were injected intraperitonially at doses 2, 4, and 8 μ mol/g body weight (bw) respectively for 30 days, after which blood hemoglobin, glycosylated hemoglobin, plasma glucose and insulin, hexokinase, glucose-6-phosphatase, fructose-1, 6-bisphosphatase, glucose-6-phosphate dehydrogenase in liver and glycogen in liver and muscle were assayed. Results. Glucose, glycosylated hemoglobin, glucose-6-phosphatase and fructose-1,6-bis phosphatase were significantly increased and insulin, hemoglobin, hexokinase, glucose-6-phosphate dehydrogenase and glycogen were significantly decreased in diabetic rats. The enzyme activities were restored to the near normal levels in diabetic rats treated with EMS and Metformin. Conclusion. Our result suggest that non glucidic nutrientEMS may act as a potent antidiabetic and insulinotropic agent by restoring the above biochemical alterations in streptozotocin -nicotinamide induced type 2 diabetes.

Antihyperglycaemic Effect of Scoparia dulcis.: Effect on Key Metabolic Enzymes of Carbohydrate Metabolism in Streptozotocin-Induced Diabetes

Abstract: In experimental diabetes, enzymes of glucose and fatty acid metabolism are markedly altered. We investigated the effect of Scoparia dulcis. L. plant extract on hepatic key metabolic enzymes of carb...

Effect of tetrahydrocurcumin on erythromycin estolate-induced lipid peroxidation in rats.

Abstract: Erythromycin estolate (EME), a potent macrolide antibiotic, generates free radicals, but their role in the development of liver toxicity is not yet well understood. The present study was carried out to investigate the effect of the antioxidant drug tetrahydrocurcumin (a metabolite of curcumin, the main component of turmeric) against EME-induced lipid peroxidation in rats. The oral administration of combined THC (80 mg/kg body weight) and EME (800 mg/kg body weight) for 15 days significantly decreased lipid peroxidation and enhanced cellular antioxidant defenses when compared with the group treated with EME alone. Supplemental histopathological examination of liver sections revealed that THC had a better antioxidant effect than Silymarin (200 mg/kg body weight), a reference drug. The results of this study indicate that THC affords significant protection against EME-induced lipid peroxidation.

Antihyperlipidemic effect of aqueous extract of Scoparia dulcis in albino rats treated with streptozotocin.

Abstract: Scoparia dulcis was examined for its ability to influence various biochemical parameters relating to diabetes mellitus and atherosclerosis. The extract of Scoparia dulcis (200 mg/kg body weight) when orally administered to streptozotocin induced diabetic rats for 6 weeks, reduced elevated serum triglycerides, phospholipids, free fatty acids, total cholesterol, very low density lipoprotein (VLDL) and low density lipoprotein (LDL)-cholesterol levels. The decreased serum high density lipoprotein (HDL)-cholesterol and antiatherogenic index (AAI) in diabetic rats were also reversed towards normalization. The ability of this extract (at 200 mg/kg) to lower triglycerides, phospholipids, free fatty acids and total cholesterol in serum and its antiatherogenic potential was compared with glibenclamide, a reference drug.

Effect of N-benzoyl-d-phenylalanine on lipid profile in liver of neonatal streptozotocin diabetic rats.

Abstract: The effect of N-benzoyl-d-phenylalanine (NBDP) and metformin combination treatment on liver lipids and lipid peroxidation markers was studied in neonatal streptozotocin (nSTZ) diabetic rats. Oral administration of NBDP (50, 100 and 200 mg/kg body weight) and metformin (500 mg/kg body weight) for 6 weeks significantly reduced the elevated blood glucose, liver cholesterol, triglycerides, free fatty acids and phospholipids. The combination treatment also caused a significant decrease in hepatic hydroxymethyl glutaryl-coenzyme A reductase, Thiobarbituric Acid Reactive Substances (TBARS) and significant increase in reduced glutathione levels. The results show that NBDP and metformin improve the hepatic lipid profile and antioxidant status in nSTZ diabetic rats. Combination treatment was more effective than either drug alone.