G. Kumar

Hypolipidaemic activity of Helicteres isora L. bark extracts in streptozotocin induced diabetic rats

In this study, the hypolipidaemic effect of an aqueous extract of the bark of Helicteres isora was investigated in streptozotocin (STZ)-induced diabetic rats. Administration of the bark extract of Helicteres isora (100 and 200 mg/kgb.w.) for 21 days resulted in significant reduction in serum and tissue cholesterol, phospholipids, free fatty acids and triglycerides in STZ diabetic rats. In addition to that, significant (p<0.05) decrease in high-density lipoprotein (HDL) whereas significant increase (p<0.05) low-density lipoprotein (LDL) and very low-density lipoprotein (VLDL) were observed in STZ diabetic rats, which were normalized after 21 days of bark extract treatment. The bark extract at a dose of 200 mg/kgb.w. showed much significant hypolipidaemic effect than at the dose of 100 mg/kgb.w.

Effects of leaves extract of Ocimum sanctum L. on arsenic-induced toxicity in Wistar albino rats

Therapeutic efficacy of oral administration of Ocimum sanctum (200mg/kg, once daily) post arsenic exposure (100 ppm in drinking water for 4 months) was investigated in rats. Animals exposed to arsenic (III) showed a significant inhibition of delta-aminolevulinic acid dehydratase (ALAD) activity, decrease in reduced glutathione (GSH) level and an increase in reactive oxygen species (ROS) in blood. On the other hand, a significant decrease in hepatic ALAD, and increase in delta-aminolevulinic acid synthetase activity were noted after arsenic exposure. These changes were accompanied by an increase TBARS level in liver and kidney. Activities of liver, kidney and brain superoxide dismutase and catalase also showed a decrease on arsenic exposure. Administration of O. sanctum post arsenic exposure, exhibited significant recovery in blood ALAD activity while, it restored blood GSH and ROS levels. Other blood biochemical variables remained unchanged on O. sanctum supplementation. Interestingly, there was a marginal, but significant depletion of arsenic from blood, liver and kidneys. The results conclude that post arsenic administration of O. sanctum has significant role in protecting animals from arsenic-induced oxidative stress and in the depletion of arsenic concentration. Further studies thus can be recommended for determining the effect of co-administrating of O. sanctum during chelating therapy with a thiol chelator.

Effect of Helicteres isora Bark Extracts on Brain Antioxidant Status and Lipid Peroxidation in Streptozotocin Diabetic Rats

Abstract The current study investigated the effect of the aqueous extract of Helicteres isora. L (Sterculiaceae) bark on oxidative stress in the brains of rats during diabetes. The aqueous extract of H. isora. bark was administered orally (100, 200 mg/kg b.w.) and the effect of the extract on blood glucose, plasma insulin, and the levels of thiobarbituric acid reactive substances (TBARS), hydroperoxides, superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), glutathione S.-transferase (GST), and reduced glutathione (GSH) were estimated in streptozotocin (STZ) diabetic rats. Tolbutamide was used as the standard reference drug. A significant increase in the activities of plasma insulin, SOD, CAT, GPx, GST, and GSH were observed in the brain on treatment with 100 and 200 mg/kg b.w. of H. isora. bark extract (HIBe) and tolbutamide for 5 weeks. Both treated groups (bark extract and drug) showed a significant decrease in TBARS and hydroperoxides formation in brain, suggesting its role in protection against lipid peroxidation–induced membrane damage. These findings suggest a possible antiperoxidative role of H. isora. bark extract that may be used for therapeutic purposes.

Antihyperlipidemic effect of Garlip, a polyherbal formulation in streptozotocin induced diabetic rats

This study was undertaken to investigate the effect of Garlip, a polyherbal drug composed of aqueous extract of six medicinal plants on blood glucose, plasma insulin, tissue lipid profile, and lipidperoxidation in streptozotocin induced diabetic rats. Aqueous extract of Garlip a, polyherbal drug was administered orally (200 mg/kg body weight) for 30 days. The different doses of Garlip 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, phospholipids and free fatty acids) were also estimated in streptozotocin induced diabetic rats. The effects were compared with tolbutamide. Treatment with Garlip and tolbutamide resulted in a significant reduction of blood glucose and increase in plasma insulin. Garlip also resulted in a significant decrease in tissue lipids and lipid peroxide formation. The effect produced by Garlip was comparable with that of tolbutamide. The decreased lipid peroxides and tissue lipids clearly showed the antihyperlipidemic and antiperoxidative effect of Garlip apart from its antidiabetic effect.

Influence of Helicteres isora administration for diabetes mellitus: its effect on erythrocyte membrane and antioxidant status.

In this study the effect of Helicteres isora L. on erythrocyte membrane bound enzymes and antioxidants activity in plasma and erythrocytes of streptozotocin (STZ) induced diabetic model was investigated. The aqueous bark extract of H. isora was administered orally for 30 days to control and STZ induced diabetic rats. The effect of bark extract on glucose, insulin, haemoglobin, glycosylated haemoglobin, TBARS, hydroperoxide, superoxide dismutase (SOD), catalase (CAT), glutathione peroxide (GPx), glutathione-S-transferase (GST), vitamins C and E, reduced glutathione (GSH) and membrane bound enzymes were studied. The levels of glucose, glycosylated haemoglobin, TBARS, hydroperoxide, and vitamin E were increased significantly whereas the level of insulin, haemoglobin, as well as antioxidants, membrane bound total ATPase, Na(+)/K(+)-ATPase, Ca(2+)-ATPase and Mg(2+)-ATPase were decreased significantly in STZ diabetic rats. Administration of bark extract to diabetic rats showed a decrease in the levels of glucose, glycosylated haemoglobin, lipid peroxidation markers and vitamin E. In addition the levels of insulin, haemoglobin, enzymatic antioxidants, vitamin C, and GSH and the activities of membrane bound enzymes also were increased in H. isora treated diabetic rats. The present study indicates that the H. isora possesses a significant favourable effect on erythrocyte membrane bound enzymes and antioxidants defense system in addition to its antidiabetic effect.

Attenuation of Helicteres isora L. bark extracts on streptozotocin-induced alterations in glycogen and carbohydrate metabolism in albino rats.

The present study was undertaken to assess the effect of Helicteres isora L. on four important enzymes of carbohydrate metabolism (glucokinase [GK], hexokinase [HK] phosphofructokinase [PFK] and fructose-1, 6-bisphosphatase [FBP]) along with glycogen content of insulin-dependent (skeletal muscle and liver) and insulin-independent tissues (kidneys and brain) in streptozotocin (STZ; 60 mg/kg)-induced model of diabetes for 30 days. Administration of bark extracts (100, 200 mg/kg) for 30 days led to decrease in plasma glucose levels by approximately 9.60% and 22.04% and 19.18% and 33.93% on 15th and 30th day, respectively, of the experiment. Liver and two-kidney weight expressed as percentage of body weight significantly increased in diabetics (P < 0.05) versus normal controls. Renal glycogen content increased by 10 folds while hepatic and skeletal muscle glycogen content decreased by 75% and 68% in diabetic controls versus controls. H. isora did not affect glycogen content in any tissue. The decreased activities of PFK, GK, FBP and HK in diabetic controls were 40%, 50%, 50% and 60% and bark extract of H. isora partially corrected this alteration. The efficacy of the bark extract was comparable with Tolbutamide, a well-known hypoglycemic drug.

Influence of Helicteres isora administration for diabetes mellitus: the effect on changes in tissue fatty acid composition.

The aim of the present study was to evaluate the effect of aqueous bark extract of Helicteres isora (HI) (Sterculiaceae) on the blood glucose, plasma insulin and fatty acid composition of the total lipids in the liver, kidney and brain of control and streptozotocin (STZ) diabetic rats. The analysis of fatty acids showed that there was a significant increase in the concentrations of palmitic acid (16:1), stearic acid (18:0) and oleic acid (18:1) in the liver, kidney and brain, whereas the concentrations of linolenic acid (18:3) and arachidonic acid (20:4) were significantly decreased in STZ diabetic rats. Oral administration of the aqueous bark extract of HI (100, 200mg/kg body weight) for 30 days to diabetic rats decreased the concentrations of fatty acids, viz., palmitic, stearic, and oleic acid, whereas linolenic and arachidonic acid were elevated. These results suggest that HI exhibits antidiabetic and antihyperlipidemic effects in STZ induced diabetic rats. It also prevents the fatty acid changes produced during diabetes. The antidiabetic and antihyperlipidemic effects of HI are more potent than those of tolbutamide, as standard drug. The results of the present study indicate that HI showed an antihyperlipidemic effect in addition to its antidiabetic effect in type 2 diabetic rats.