Antidiabetic effect ofT. arjuna bark extract in alloxan induced diabetic rats

The present study was carried out to evaluate the antidiabetic effect of T. arjuna stembark extract and to study the activities of hexokinase, aldolase and phosphoglucoisomerase, and gluconeogenic enzymes such as glucose-6-phosphatase and fructose-1,6-diphosphatase in liver and kidney of normal and alloxan induced diabetic rats. Oral administration of ethanolic extract of bark (250 and 500mg/kg body weight) for 30 days, resulted in significant decrease of blood glucose from 302.67±22.35 to 82.50±04.72 and in a decrease in the activities of glucose-6-phosphatase, fructose-1,6-disphosphatase, aldolase and an increase in the activity of phosphoglucoisomerase and hexokinase in tissues. However, in the case of 250 mg/kg body weight of extract, less activity was observed. The study clearly shows that the bark extract ofT. arjuna possesses potent antidiabetic activity.     

Effect of water extract of <Emphasis Type="Italic">Trichosanthes dioica</Emphasis> fruits in streptozotocin induced diabetic rats

In rats with streptozotocin induced severe diabetes mellitus, aqueous extract of Trichosanthes dioica fruits at a dose of 1000mg/kg body weight daily once for 28 days reduced the levels of fasting blood glucose, postprandial glucose, asparate amino transferase, alanine amino transferase, alkaline phosphatase, creatinine, urine sugar and urine protein where as total protein and body weight was increased. No toxic effect was observed during LD50. Our study suggests that further detailed toxicity studies and mechanism of action of T. dioica would be useful for undertaking human trials.     

Antihyperglycemic and antilipidperoxidative effects of<Emphasis Type="Italic">Tephrosia purpurea</Emphasis> seed extract in streptozotocin induced diabetic rats

The aim of the present study was to evaluate the antihyperglycemic and antilipidperoxidative effects of ethanolic seed extract ofTephrosia purpurea (TpEt) in streptozotocin induced diabetic rats. Hyperglycemia associated with an altered hexokinase and glucose 6 phosphatase activities, elevated lipid peroxidation, disturbed enzymatic and non-enzymatic antioxidants status were observed in streptozotocin induced diabetic rats. Oral administration of “TpEt” at a dose of 300mg/kg bw showed significant antihyperglcemic and antilipidperoxidative effects as well as increased the activities of enzymatic antioxidants and levels of non enzymatic antioxidants. We also noticed that the antihyperglycemic effect of plant drug (TpEt) was comparable to that of the reference drug glibenclamide. Our results clearly indicate that “TpEt” has potent antihyperglycemic and antilipidperoxidative effects in streptozotocin induced diabetic rats and therefore further studies are warranted to isolate and characterize the bioactive antidiabetic principles from “TpEt”.     

Effect ofOcimum sanctum (Tulsi) and vitamin E on biochemical parameters and retinopathy in streptozotocin induced diabetic rats

This study was carried out to see the effect of the aqueous extract ofOcitum sanctum Linn (Tulsi) with Vitamin E on biochemical parameters and retinopathy in the streptozotocin-induced diabetic albino male rats. Adult albino male rats weighing 150–200 gm were made diabetic by intraperitoneal injection of streptozotocin in the dose 60 mg/kg in citrate buffer (pH 6.3). The diabetic animals were left for one month to develop retinopathy. Biochemical parameters like plasma glucose, oral glucose tolerance and glycosylated hemoglobin HbA_1c, were measured along with lipid profile, and enzymes like glutathione peroxidase (GPX), lipid peroxidase (LPO), superoxide dismutase (SOD), catalase (CAT) and glutathione-S-transferase (GST) in normal, untreated diabetic rats and diabetic rats treated withOcimum sanctum L extracts and vitamin E. Fluorescein angiography test was done for assessing retinopathy. Results on biochemical parameters were analyzed statistically by using ANOVA followed by Dunnet's ‘t’-test. A p-value of <0.05 was considered as significant. Evaluation of biochemical profile in treated groups showed statistically significant reduction in plasma levels of glucose, HbA_1c, lipid profile and LPO, and elevation of GPX, SOD, CAT and GST. Treatment of the diabetic animals withOcimum sanctum and Vitamin E, alone and in combination for 16 weeks showed reversal of most of the parameters studied including plasma glucose levels. Angiography showed improvement in retinal changes following combined antidiabetic treatment.     

Antidiabetic and antioxidant effects of <Emphasis Type="Italic">Picrorhiza kurrooa</Emphasis> rhizome extracts in diabetic rats

Picrorhiza kurrooa is mentioned in Ayurveda for the treatment of many disorders, but it has not been subjected to systematic scientific investigations to assess its antidiabetic effect. The oral administration of aqueous and methanol extracts of P. kurrooa rhizomes (250 and 500 mg / kg body weight / day) for 15 days significantly reduced blood glucose, glycosylated haemoglobin and increased total hemoglobin, plasma insulin in alloxan-induced diabetes in albino rats. The treatment also showed significant correction in the level of nitric oxide radicals, superoxide radicals, peroxynitrite radical, lipid peroxidation, glutathione, glutathione reductase, glutathione-S-transferase, glutathione peroxidase, superoxide dismutase and catalase in the pancreas of alloxan diabetic rats.     

Hypoglycemic, lipid lowering and antioxidant activities in root extract of Anthocephalus indicus in alloxan induced diabetic rats

The present study was carried out to evaluate the hypoglycemic, lipid lowering and antioxidant activities in root extract of Anthocephalus indicus (A indicus) in alloxan inducd diabetic rats. Oral administration of ethanol extract of root (500mg/ kg body weight) for 21 days resulted in significant decrease in the levels of blood glucose, triglycerides, total cholesterol, phospholipid and free fatty acids. Furthermore, the root extract (100–400μg) inhibited the generation of superoxide anions and hydroxyl radicals, in both enzymic and non-enzymic systems, in vitro. The result of the present study demonstrated hypoglycemic, lipid lowering and antioxidant activities in root extract of A indicus, which could help in prevention of diabetic dyslipidemia and related diseases.     

Evaluation of the radioprotective effect of turmeric extract and vitamin E in mice exposed to therapeutic dose of radioiodine

The aim of this study was to evaluate the radioprotective effect of turmeric extract (40 mg/kg body weight) and vitamin E (α- tocopherol acetate, 400 IU/kg body weight) supplementation on lipid peroxidation, reduced glutathione and antioxidant defense enzymes in various organs like liver, kidney and salivary glands at 24 h in adult Swiss mice. ¹³¹Iodine exposure significantly increased lipid peroxidation in kidney and salivary glands in comparison to control animals. Pre supplementation with turmeric extract for 15 days showed significant lowering of lipid peroxidation in kidney. On the other hand vitamin E pre supplementation showed marked reduction in lipid peroxidation in salivary glands. Reduced glutathione levels decreased significantly in liver after radiation exposure. However, pre supplementation with turmeric extract and vitamin E did not improve glutathione levels in liver. In conclusion, we have observed differential radioprotective effect of turmeric extract and vitamin E in kidney and salivary glands. However, Vitamin E seems to offer better radioprotection for salivary glands which is known to be the major site of cellular destruction after radioiodine therapy in patients.     

Protective influence of vitamin E on the antioxidant defence system in the whole blood and liver of normal and alloxan-induced diabetic rats

The effect of oral administration of vitamin E for twenty-eight consecutive days on blood glucose, reduced glutathione levels, antioxidant enzymes (superoxide dismutase and catalase activities), and levels of malondialdehyde (as an index of free radical-mediated lipid peroxidation) was observed in the whole blood and liver of normal and alloxan-induced diabetic rats. It was found that oral administration of vitamin E significantly (p<0.05) lowered the blood glucose level and increased the body weight of the diabetic rats. The activities of superoxide dismutase and levels of reduced glutathione increased significantly (p<0.05) while the level of lipid peroxidation decreased.     

Hypoglycaemic, hypolipidemic and antioxidant properties of tulsi (Ocimum sanctum linn) on streptozotocin induced diabetes in rats

Effect of oral administration of 200 mg/Kg body weight of the aqueous extract ofOcimum sanctum (Tulsi) mixed with diet for eight weeks to diabetic (streptozotocin induced) rats was studied. There was significant reduction in fasting blood glucose, serum lipid profile, lipid peroxidation products, (LPO) and improvement in glucose tolerance. The aqueous extract also decreased LPO formation (thiobarbituric acid reactive substances TBARS) and increased antioxidant enzymes superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPX), glutathione transferase (GT) and one antioxidant reduced glutathione (GSH) in plasma and rat liver, lung, kidney and brain. The decrease in TBARS and increase in GSH, SOD, CAT, GPX, and GT clearly shows the antioxidant property ofOcimum sanctum.     

Preliminary studies on the hypoglycemic effect of <Emphasis Type="Italic">Peganum harmala</Emphasis> L. Seeds ethanol extract on normal and streptozotocin induced diabetic rats

Peganum harmala L. (Zygophyllaceae) is a traditional medicine used for the treatment of variety of human ailments, including antidepression, hallucination, antileishmaniasis etc. We report for first time the hypoglycemic activity of the ethanolic extract of this plant at two dose levels of 150 and 250mg/kg bw in sucrose challenged normal as well as in rats with streptozotocin induced diabetes. The oral administration of ethanolic extract causes maximum fall of blood glucose level to 22.9% (p<0.05) and 29.4% (p<0.01) respectively with the two doses in normal and 30.3% (p<0.01) and 48.4% (p<0.001) in diabetic rats. The standard drug metformin treated group showed 28.0% (p<0.01) and 45.5% (p<0.001) respectively in normal and diabetic rats. The above results show that the ethanolic extract of P. harmala is as effective as metformin in reducing the blood glucose levels of normoglycemic and streptozotocin-induced diabetic rats.     

Effect of<Emphasis Type="Italic">Coccinia indica</Emphasis> (L.) and<Emphasis Type="Italic">Abroma augusta</Emphasis> (L.) on glycemia,lipid profile and on indicators of end-organ damage in streptozotocin induced diabetic rats

InAyurvedic system of medicine in India, not only extracts of one plant or the other but also a combination of plant extracts are used for the treatment of diabetes mellitus. The present paper reports the combined effect ofAbroma augusta andCoccinia indica known to be useful for the treatment of diabetes in Ayurveda on the fasting blood sugar, glucose tolerance and lipid profile of Streptozotocin (STZ) induced albino rats. 300mg of water extract of the mixture of dried powdered roots ofA. augusta and leaves ofC. indica in equal proportions was given once daily for 8 weeks. After 8 weeks of treatment of Streptozotocin (STZ) diabetic rats, the fasting blood sugar came down to almost normal value and improvement in glucose tolerance and serum lipid profile were also observed.