Antihyperlipidemic effect of Eugenia jambolana seed kernel on streptozotocin-induced diabetes in rats.

Abnormalities in lipid profile are one of the most common complications in diabetes mellitus, which is found in about 40% of diabetics. In the present study, anti-hyperlipidemic efficacy of Eugenia jambolana seed kernel (EJs-kernel) was evaluated in streptozotocin (STZ)-induced diabetic rats and the efficacy was compared with standard hypoglycemic drug, glibenclamide. The effect of oral administration of ethanolic extract of EJs-kernel (100 mg/kg body weight) was examined on the levels of cholesterol, phospholipids, triglycerides and free fatty acids in the plasma, liver and kidney tissues of STZ (55 mg/kg body weight)-induced diabetic rats. The plasma lipoproteins and tissues fatty acid composition were also monitored. STZ-induced diabetic rats, showed significant increase in the levels of cholesterol, phospholipids, triglycerides and free fatty acids which were considerably restored to near normal in EJs-kernel or glibenclamide treated animals. The plasma lipoproteins (HDL, LDL, VLDL-cholesterol) and fatty acid composition were altered in STZ-induced diabetic rats and these levels were also reverted back to near normalcy by EJs-kernel or glibenclamide treatment. It may be concluded that, EJs-kernel possesses hypolipidemic effect, which may be due to the presence of flavonoids, saponins, glycosides and triterpenoids in the extract. The hypolipidemic effect mediated by EJs-kernel may also be anticipated to have biological significance and provide a scientific rationale for the use of EJs-kernel as an anti-diabetic plant.     

Protective effect of Umbelliferone on membranous fatty acid composition in streptozotocin-induced diabetic rats

Umbelliferone (UMB), a natural antioxidant, is benzopyrone in nature, and it is present in the fruits of golden apple and bitter orange. Earlier we evaluated and reported the effect of Umbelliferone on antidiabetic, antioxidant and antihyperlipidemic properties, and this study was designed to evaluate the effect of Umbelliferone on membrane fatty acid composition and histopathology of liver and kidney of control and streptozotocin (STZ) diabetic rats. Male albino Wistar rats (180-200 g) were made diabetic by an intraperitonial administration of STZ (40 mg/kg). The control and diabetic rats were treated with Umbelliferone and glibenclamide dissolved in 10% dimethyl sulfoxide for 45 days. Diabetic rats had decreased insulin and increased glucose, and increased levels of thiobarbituric acid reactive substances, lipid hydroperoxides and conjugated dienes. The levels of palmitic, stearic and oleic acids increased and the levels of linolenic and arachidonic acids decreased in diabetic rats as compared with control rats. Thus, the saturated fatty acids and monounsaturated fatty acids increased and the polyunsaturated fatty acids decreased in diabetic rats. Diabetic rats had decreased liver weight and increased activities of alanine transaminase and aspartate transaminase; increased kidney weight and urine albumin, and decreased levels of urea, uric acid and creatinine in the urine. Histopathological studies of liver and kidney in diabetic rats showed fatty changes surrounding portal triad; enlargement of lining cells of tubules, fatty infiltration, large area of hemorrhage and lymphocyte infiltration. Treatment with Umbelliferone and glibenclamide reversed these changes to near normalcy. Our results showed that Umbelliferone has a protective effect on membrane fatty acid composition of liver and kidney as supported by antioxidant and antihyperlipidemic effects of Umbelliferone reported earlier as evidenced by improved histopathological changes, hepatic and nephritic markers, indicating recovery from the risk of diabetic complications.     

Protective effect of boldine on oxidative mitochondrial damage in streptozotocin-induced diabetic rats.

Increased oxidative stress has been suggested to be involved in the pathogenesis and progression of diabetic tissue damage. Several antioxidants have been described as beneficial for oxidative stress-associated diseases. Boldine ([s]-2,9-dihydroxy-1, 10-dimethoxyaporphine) is a major alkaloid found in the leaves and bark of boldo (Peumus boldus Molina), and has been shown to possess antioxidant activity and anti-inflammatory effects. From this point of view, the possible anti-diabetic effect of boldine and its mechanism were evaluated. The experiments were performed on male rats divided into four groups: control, boldine (100 mg kg(-1), daily in drinking water), diabetic [single dose of 80 mg kg(-1)of streptozotocin (STZ), i.p.] and diabetic simultaneously fed with boldine for 8 weeks. Diabetic status was evaluated periodically with changes of plasma glucose levels and body weight in rats. The effect of boldine on the STZ-induced diabetic rats was examined with the formation of malondialdehydes and carbonyls and the activities of endogenous antioxidant enzymes (superoxide dismutase and glutathione peroxidase) in mitochondria of the pancreas, kidney and liver. The scavenging action of boldine on oxygen free radicals and the effect on mitochondrial free-radical production were also investigated. The treatment of boldine attenuated the development of hyperglycemia and weight loss induced by STZ injection in rats. The levels of malondialdehyde (MDA) and carbonyls in liver, kidney and pancreas mitochondria were significantly increased in STZ-treated rats and decreased after boldine administration. The activities of mitochondrial manganese superoxide dismutase (MnSOD) in the liver, pancreas and kidney were significantly elevated in STZ-treated rats. Boldine administration decreased STZ-induced elevation of MnSOD activity in kidney and pancreas mitochondria, but not in liver mitochondria. In the STZ-treated group, glutathione peroxidase activities decreased in liver mitochondria, and were elevated in pancreas and kidney mitochondria. The boldine treatment restored the altered enzyme activities in the liver and pancreas, but not the kidney. Boldine attenuated both STZ- and iron plus ascorbate-induced MDA and carbonyl formation and thiol oxidation in the pancreas homogenates. Boldine decomposed superoxide anions, hydrogen peroxides and hydroxyl radicals in a dose-dependent manner. The alkaloid significantly attenuated the production of superoxide anions, hydrogen peroxide and nitric oxide caused by liver mitochondria. The results indicate that boldine may exert an inhibitory effect on STZ-induced oxidative tissue damage and altered antioxidant enzyme activity by the decomposition of reactive oxygen species and inhibition of nitric oxide production and by the reduction of the peroxidation-induced product formation. Boldine may attenuate the development of STZ-induced diabetes in rats and interfere with the role of oxidative stress, one of the pathogeneses of diabetes mellitus.     

Protective effect of herbomineral formulation (Dolabi) on early diabetic nephropathy in streptozotocin-induced diabetic rats

The effect of a herbomineral formulation (HMF) on early diabetic nephropathy was investigated. Diabetes was induced in Wistar rats by administering streptozotocin (55 mg/kg, intraperitoneally). The occurrence of early diabetic nephropathy in rats was revealed by high plasma glucose and depleted liver glycogen, decreased glucose uptake by peripheral tissue, impaired renal function, increased antioxidants and lipid peroxidation in kidney. These changes were accompanied by elevated malondialdehyde, glutathione and superoxide dismutase activity in kidney. Furthermore, increased total urine volume, urinary albumin excretion rate, urinary albumin to creatinine ratio, increased relative kidney weight, decreased glomerular filtration rate (GFR) and urinary creatinine were also observed in diabetic nephropathy rats. HMF treatment significantly lowered blood glucose, glycosylated hemoglobin, creatinine, blood urea nitrogen, triglycerides, total cholesterol, serum albumin level, total urine volume, urinary albumin excretion rate, urinary albumin to creatinine ratio and relative kidney weight, and increased urinary creatinine and GFR. Altered levels of antioxidants, viz. lipid peroxidation, glutathione and superoxide dismutase (SOD), in kidney of diabetic nephropathy rats were restored. Histopathological findings indicated dense mesangial matrix in the glomeruli of diabetic nephropathy rats, which may be due to over-activation of matrix metalloproteinases and was reduced following HMF treatment. Our experimental findings clearly demonstrate that HMF has an ability to prevent the progression of early diabetic nephropathy. Such protective effect of HMF might be due to the presence of flavonoids (catechin, quercetin, rutin) and triterpene saponins (oleanolic acid and gymnemic acid) which are known to possess potent antioxidant properties.     

罗布麻提取物对STZ糖尿病大鼠肾损害的防护作用

本文探讨了罗布麻提取物 (AV) 对STZ大鼠糖尿病肾脏损害的防护作用及部分作用机制。采用链脲佐菌素 (STZ) 诱导大鼠糖尿病模型方法, 观察8周时大鼠血糖、肾功能、氧化应激等指标以及经AV治疗后的变化。结果显示, 糖尿病大鼠的血糖、血尿素氮、24 h尿蛋白含量、尿量、肾脏肥大指数、肾皮质MDA含量显著升高; 肾皮质SOD、GSH活性显著降低。AV干预治疗组的上述指标得到改善, 具有显著性差异。实验结果表明, AV对STZ大鼠糖尿病肾功能有明显的防护作用, 其作用可能与抑制肾脏氧化应激作用有关。     

Protective effects of bendazac lysine on diabetic peripheral neuropathy in streptozotocin-induced diabetic rats

1. Diabetic neuropathy is a many faceted complication of both type I and II diabetes. The aim of the present study was to investigate the effects of bendazac lysine (BDL), an anticataract drug, on experimental diabetic peripheral neuropathy (DPN) in rats. 2. Diabetes was induced in rats by intraperitoneal injection of 75 mg/kg streptozotocin (STZ) dissolved in 0.1 mol/L citrate buffer (pH 4.4). Bendazac lysine was administered to rats at doses of 50, 100 and 200 mg/kg twice a day for 12 weeks. 3. Diabetic rats without treatment showed hypopraxia, polydipsia, polyuria, slow weight gain, cataract, increased tail-flick threshold temperature, decreased motor nerve conduction velocity (nd induced pathological morphological changes of myelinated nerve fibres. All these symptoms were ameliorated in diabetic rats treated with BDL. Bendazac lysine ameliorated the blood glucose concentration, glycosylated haemoglobin levels and insulin levels in the plasma of diabetic rats, reduced aldose reductase activity in erythrocytes and advanced glycation end-products in both nerves and serum and increase the activity of glutathione peroxidase in the nerves and Na(+)/K(+)-ATPase in the nerves and erythrocytes. 4. Bendazac lysine exerts its protective effects against the progression of diabetic peripheral neuropathy in STZ-diabetic rats through multiple mechanisms and is a potential drug for the prevention of deterioration in DPN.     

口服参芪扶正注射液对糖尿病大鼠肾脏的保护作用

目的 :探讨参芪扶正注射液对糖尿病大鼠肾脏的保护作用及其机制。方法 :取 6 0只健康雄性Sprague Dawley种大鼠 ,腹腔内注射链脲佐菌素 (6 0mg·kg-1)造成糖尿病模型 ,然后将其中 32只大鼠给参芪扶正注射液 2 0 0mg·kg-1·d-1口服 ,共 8周 ,同时取 15只糖尿病大鼠和 10只健康大鼠作对照。试验前后分别观察各组大鼠血压、尿蛋白、肾功能、血浆血管肾张素AngⅡ含量以及肾组织转化因子 (TGF β1)、原癌基因c fos的表达。结果 :参芪扶正注射液可控制糖尿病肾脏体积的扩大、血压的升高 ,减少尿蛋白的排出 ,改善肾功能 (BUN、Cr均下降 )、降低血浆AngⅡ水平 ,与对照组相比差异均有显著或非常显著性。同时还可降低TGF β1、c fos在肾组织中的表达 ,其灰度值测定与对照组相比差异具非常显著性 (P <0 .0 1)。结论 :参芪扶正注射液可通过改善血液循环 ,降低血浆AngⅡ水平 ,控制血压 ,改善肾小球的“三高状态” ,从而抑制了ECM增生 ,以达保护肾功能 ,缓延肾小球硬化之目的。     

Protective effect of caffeine on streptozotocin-induced beta-cell damage in rats

Many epidemiological studies have shown that coffee consumption reduces the risk of type 2 diabetes mellitus (T2D), although the reasons as to why remain unclear. In this study we investigated the effect of caffeine on pancreatic beta-cell damage in rats using the diabetogenic agent, streptozotocin (STZ). Wistar rats were given intraperitoneal injections of saline or caffeine (10, 50 or 100 mg kg(-1)). After 15 min, the rats were injected with a citrate buffer or 65 mg kg(-1) STZ. Three days after injection, an oral glucose tolerance test (OGTT) was performed on the rats. Furthermore, three days after the OGTT, the pancreas was isolated and homogenized, followed by determination of insulin content. STZ treatment significantly increased the plasma glucose level compared with the control at all times during the OGTT, which was significantly diminished by caffeine pretreatment at all doses. STZ treatment significantly decreased the plasma insulin level, however, which was not recovered by caffeine pretreatment. Pancreatic insulin content was significantly reduced by STZ treatment compared with the control, which was significantly recovered by caffeine pretreatment at a dose of 100 mg kg(-1) (P<0.01). We showed that caffeine protects pancreatic beta-cells against STZ toxicity. Further investigation will be required to understand the protective effect of caffeine against beta-cell destruction in T2D.     

Antihyperglycemic effect of andrographolide in streptozotocin-induced diabetic rats

The antihyperglycemic action of andrographolide, an active principle in the leaves of Andrographis paniculata (Burm. f.) Nees, was investigated in streptozotocin-induced diabetic rats (STZ-diabetic rats). Oral treatment of andrographolide decreased the plasma glucose concentrations of STZ-diabetic rats in a dose-dependent manner. Similar treatment with andrographolide also decreased the plasma glucose in normal rats and the maximal effect was more marked than that in STZ-diabetic rats. Andrographolide at the effective dose (1.5 mg/kg) significantly attenuated the increase of plasma glucose induced by an intravenous glucose challenge test in normal rats. In the isolated soleus muscle of STZ-diabetic rats, andrographolide enhanced the uptake of radioactive glucose in a concentration-dependent manner. Moreover, the mRNA and protein levels of the subtype 4 form of the glucose transporter (GLUT4) in soleus muscle were increased after repeated intravenous administration of andrographolide in STZ-diabetic rats for 3 days. These results suggest that andrographolide can increase the glucose utilization to lower plasma glucose in diabetic rats lacking insulin.     

Antidiabetic effect of Streblus asper in streptozotocin-induced diabetic rats

Context: In the Indian traditional system of medicine, Streblus asper Lour (Moraceae) is prescribed for the treatment of diabetes mellitus.

Objective: In the present study, α-amyrin acetate isolated from S. asper, and the petroleum ether extract of S. asper stem bark (PESA) was screened for their antidiabetic properties in streptozotocin (STZ)-induced diabetic rats.

Materials and methods: Successive Soxhlet extraction of the dried stem bark with petroleum ether and then with ethanol (95%) yielded petroleum ether and ethanol extracts, respectively, which were concentrated under reduced pressure. Hyperglycemia was induced in rats by STZ (50?mg/kg, b.w.). Twenty-four hours after STZ induction, respective groups of diabetic rats received PESA (100, 250 and 500?mg/kg, b.w.) and α-amyrin acetate (25, 50 and 75?mg/kg, b.w.) respectively, orally daily for 15 days. Glibenclamide (0.5?mg/kg, orally) served as a reference. Blood glucose levels were measured on every 5th day during the 15 days of treatment. The serum lipid profiles and biochemical parameters, viz., serum glutamic oxaloacetic transaminase (SGOT), serum glutamic pyruvic transaminase (SGPT), alkaline phosphatase (ALP), insulin and glycosylated hemoglobin level, were measured.

Results: PESA significantly (p < 0.01) normalized blood-glucose levels and serum biochemical parameters as compared with those of STZ controls. α-Amyrin acetate (75?mg/kg, b.w.) exhibited maximum glucose lowering effect (71.10%) in diabetic rats compared to the other dose (25, 50?mg/kg) at the end of the study. The protective effect was further confirmed by histopathological examination of the liver.

Conclusion: PESA and α-amyrin acetate demonstrated remarkable antidiabetic activity in STZ-induced diabetic rats.     

Hypoglycaemic effect of Melothria heterophylla in streptozotocin-induced diabetic rats

Context: In the Indian traditional system of medicine, Melothria heterophylla (Lour.) Cogn., (Cucurbitaceae) is prescribed for the treatment of diabetes mellitus.

Objective: In the present study, the antidiabetic effect of ethanol extract of Melothria heterophylla (EEMH), and its active isolated constituents were investigated in streptozotocin (STZ)-induced diabetic Swiss albino rats.

Method: Successive Soxhlet extraction of the dried total aerial parts with petroleum ether for defatting and then with ethanol (95%) to obtain ethanol extract, which was concentrated under reduced pressure. Hyperglycemia was induced in rats by STZ (50 mg/kg, body weight). Twenty-four hours after STZ induction, respective groups of diabetic rats received EEMH (200 and 400 mg/kg, body weight), gallic acid (GA) (2 and 4 mg/kg, body weight), and rutin (RU) (2 and 4 mg/kg, body weight), respectively, orally daily for 15 days. Glibenclamide (0.5 mg/kg, orally) served as reference. Blood glucose levels and change in body weight were measured on every 5^th day during 15 days of treatment. Biochemical parameters, viz., serum glutamic oxaloacetic transaminase (SGOT), serum glutamic pyruvic transaminase (SGPT), alkaline phosphatase (ALP) and serum insulin, were measured.

Results: EEMH and its active constituents significantly (p < 0.01) normalized blood glucose levels and serum biochemical parameters as compared to those of STZ controls. Both GA (4 mg/kg) and RU (4 mg/kg) exhibited maximum glucose lowering effect (69.1 and 66.7%, respectively) in diabetic rats compared to the other dose (2 mg/kg) at the end of the study. EEMH, gallic acid and RU also showed significant increase in serum insulin, and body weight of STZ-induced diabetic rats.

Conclusion: Therefore, ethanol extract of Melothria heterophylla, GA and RU demonstrated remarkable antidiabetic activity in STZ-induced diabetic rats.     

Hypoglycaemic effect of Melothria heterophylla in streptozotocin-induced diabetic rats

Context: In the Indian traditional system of medicine, Melothria heterophylla (Lour.) Cogn., (Cucurbitaceae) is prescribed for the treatment of diabetes mellitus. Objective: In the present study, the antidiabetic effect of ethanol extract of Melothria heterophylla (EEMH), and its active isolated constituents were investigated in streptozotocin (STZ)-induced diabetic Swiss albino rats. Method: Successive Soxhlet extraction of the dried total aerial parts with petroleum ether for defatting and then with ethanol (95%) to obtain ethanol extract, which was concentrated under reduced pressure. Hyperglycemia was induced in rats by STZ (50 mg/kg, body weight). Twenty-four hours after STZ induction, respective groups of diabetic rats received EEMH (200 and 400 mg/kg, body weight), gallic acid (GA) (2 and 4 mg/kg, body weight), and rutin (RU) (2 and 4 mg/kg, body weight), respectively, orally daily for 15 days. Glibenclamide (0.5 mg/kg, orally) served as reference. Blood glucose levels and change in body weight were measured on every 5(th) day during 15 days of treatment. Biochemical parameters, viz., serum glutamic oxaloacetic transaminase (SGOT), serum glutamic pyruvic transaminase (SGPT), alkaline phosphatase (ALP) and serum insulin, were measured. Results: EEMH and its active constituents significantly (p < 0.01) normalized blood glucose levels and serum biochemical parameters as compared to those of STZ controls. Both GA (4 mg/kg) and RU (4 mg/kg) exhibited maximum glucose lowering effect (69.1 and 66.7%, respectively) in diabetic rats compared to the other dose (2 mg/kg) at the end of the study. EEMH, gallic acid and RU also showed significant increase in serum insulin, and body weight of STZ-induced diabetic rats. Conclusion: Therefore, ethanol extract of Melothria heterophylla, GA and RU demonstrated remarkable antidiabetic activity in STZ-induced diabetic rats.     

阿魏酸哌嗪对糖尿病大鼠肾脏的保护作用

目的：探讨阿魏酸哌嗪对糖尿病大鼠肾脏的保护作用及其机制。方法：取60只雄性SD大鼠，腹腔内注射链脲佐菌素（60mg.kg^-1)制造糖尿病模型，然后，将其中30只大鼠给阿魏酸哌嗪10mg.d^-1灌胃，共8周。同时取10只糖尿病大鼠和10只健康大鼠作对照。实验前后分别观察各组大鼠血压，尿蛋白，肾功能，血浆血管紧张素Ⅱ（AngⅡ）含量和肾组织转化因子（TGF－β1）和原癌基因（c-fos)。结果：阿魏酸哌嗪可控制糖尿病肾脏体积的扩大，血压的升高，减少尿蛋白的排出及改善肾功能，降低AngⅡ水平，同时还可减轻TGF－β1、c-fos的表达，与对照组相比，差异均有显著性（P＜0．05或P＜0．01）。结论：阿魏酸哌嗪可通过改善血液循环，降低血浆AngⅡ水平，控制血压，改善肾小球的“三高状态”，从而抑制了ECM增生，达到保护肾功能，延缓肾小球硬化之目的。     

Effect of ethanolic extract of Eugenia jambolana seeds on gastric ulceration and secretion in rats.

Eugenia jambolana (Jamun) fruit has been reported to give soothing effect on human digestive system. Present study includes the effect of ethanolic extract of seeds of E. jambolana (EJE) against gastric ulcers induced by 2 h cold restraint stress (CRS), aspirin (ASP, 200 mg/kg, 4 h), 95% ethanol (EtOH, 1 ml/200 g, 1 h) and 4 h pylorus ligation (PL) in rats. To ascertain the mechanism of action of EJE, its effect was studied on mucosal offensive acid-pepsin secretion, lipid peroxidation (LPO, free radical) and defensive mucin secretion, cell proliferation, glycoprotein and glutathione (GSH, an antioxidant). Acute and subacute toxicity studies were also conducted for the safety profile of Eugenia jambolana. EJE 200 mg/kg, when administered orally for 10 days in rats was found to reduce the ulcer index in all gastric ulcer models. It tended to decrease acid-pepsin secretion, enhanced mucin and mucosal glycoprotein and decreased cell shedding but had no effect on cell proliferation. It showed antioxidant properties indicated by decrease in LPO and increase in GSH levels in the gastric mucosa of rats. Acute toxicity study indicated LD50 to be more than 10 times (>2000 mg/kg) of the effective ulcer protective dose while subactue toxicity study (>1000 mg/kg) indicated no significant change in the general physiological and haematological parameters, liver and renal function tests. The result of the present study indicates that E. jambolana seed has gastro-protective properties mainly through promotion of mucosal defensive factors and antioxidant status and decreasing lipid peroxidation.     

Protective effect of rutin on lipids, lipoproteins, lipid metabolizing enzymes and glycoproteins in streptozotocin-induced diabetic rats

The protective role of rutin on lipids, lipoproteins, lipid metabolizing enzymes and glycoproteins in streptozotocin-induced diabetic rats has been studied. A single intraperitoneal injection of streptozotocin (50 mg kg(-1)) to rats led to a significant (P < 0.05) increase in the levels of lipids (cholesterol, triglycerides, free fatty acids and phospholipids) in plasma and tissues (liver, kidney, heart and brain). The levels of low density and very low density lipoprotein (LDL and VLDL, respectively) cholesterol were increased, whereas the levels of high density lipoprotein (HDL) cholesterol were decreased significantly (P < 0.05) in plasma. The activity of 3-hydroxy 3-methylglutaryl coenzyme A (HMG CoA) reductase increased significantly (P < 0.05) in liver, kidney and heart, and the activity of lipoprotein lipase (LPL) and lecithin cholesterol acyltransferase (LCAT) decreased significantly (P < 0.05) in the plasma of diabetic rats. Streptozotocin injection also increased the levels of glycoproteins such as hexose, hexosamine, fucose and sialic acid in plasma, liver and kidney. Oral administration of rutin to streptozotocin-induced diabetic rats significantly (P < 0.05) decreased the levels of lipids in plasma and tissues. The levels of plasma HDL-cholesterol increased and the levels of LDL- and VLDL-cholesterol decreased significantly (P < 0.05). The activity of HMG CoA reductase decreased in the tissues and the activity of plasma LPL and LCAT increased significantly (P < 0.05). The levels of glycoproteins were found to be significantly (P < 0.05) decreased in plasma, liver and kidney of rutin-treated diabetic rats. Rutin administration to normal rats did not exhibit any significant (P < 0.05) changes in any of the parameters studied. In conclusion, the beneficial effect of rutin on lipids, lipoproteins, lipid metabolizing enzymes and glycoproteins could be due to its antioxidant property.     

Neuroprotective effect of ginger on anti-oxidant enzymes in streptozotocin-induced diabetic rats

The aim of the present study was to investigate the effect of ginger on oxidative stress markers in the mitochondrial fractions of cerebral cortex (CC), cerebellum (CB), hippocampus (HC) and hypothalamus (HT) of diabetic rats. Diabetes exacerbates neuronal injury induced by hyperglycemia mediated oxidative damage. A marked decrease in anti-oxidant marker enzymes, superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), glutathione reductase (GR), reduced glutathione (GSH) and increase in malondialdehyde (MDA) was observed in the diabetic rats. Decreased activities of anti-oxidant enzymes in diabetic rats were augmented on oral administration of ginger. Moreover, ginger administration depleted the MDA level, which was earlier increased in the diabetic rats. These results suggest that ginger exhibit a neuroprotective effect by accelerating brain anti-oxidant defense mechanisms and down regulating the MDA levels to the normal levels in the diabetic rats. Thus, ginger may be used as therapeutic agent in preventing complications in diabetic patients.     

Protective effect of bezafibrate on streptozotocin-induced oxidative stress and toxicity in rats

The present study was aimed to find out the protective effect of bezafibrate on lipid peroxidation (LPO), activities of both enzymatic and non-enzymatic antioxidants and histopathological examination of pancreas in streptozotocin (STZ)-induced diabetic rats. Experimental diabetes was induced by a single dose of STZ (60mg/kg, i.p.) injection. The oxidative stress was measured by tissue LPO level, reduced glutathione (GSH) content and by enzymatic activities of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx) and glutathione reductase (GR) in liver and pancreas. Biochemical observations were further substantiated with histological examination of pancreas. The increase in blood glucose, LPO level with reduction in GSH content and decreased enzymatic activities were the salient features observed in diabetic control rats. Administration of bezafibrate (30mg/kg day, p.o.) for 15 days caused a significant reduction in blood glucose and LPO level in STZ treated rats (group III) when compared with diabetic control rats (group II). Furthermore, bezafibrate treated diabetic rats (group III) showed significant increase in the activities of both enzymatic and non-enzymatic antioxidants when compared to diabetic control rats (group II). Degenerative changes of pancreatic beta-cells in STZ treated rats were minimized to near normal morphology by administration of bezafibrate as evident by histopathological examination. The results obtained clearly indicate the role of oxidative stress in the induction of diabetes and suggest a protective effect of bezafibrate in this animal model.     

Renoprotective effect of aged garlic extract in streptozotocin-induced diabetic rats

Objective:

Aged garlic extract (AGE) has been proven to exhibit antioxidant, hypolipidemic, hypoglycemic and antidiabetic properties. However, its effect on diabetic nephropathy was unexplored. Therefore, the present study was designed to investigate the renoprotective effect of AGE in streptozotocin-induced diabetic rats.

Materials and Methods:

Albino Wistar rats were induced with diabetes by a single intraperitoneal injection of 45 mg/kg b.w. of streptozotocin. Commercially available AGE was supplemented orally at a dose of 500 mg/kg body weight/day. Aminoguanidine, which has been proven to be an anti-glycation agent was used as positive control and was supplemented at a dose of 1 g/L in drinking water. The serum and urinary biochemical parameters were analyzed in all the groups and at the end of 12 weeks follow up, the renal histological examination were performed using H & E and PAS staining.

Results:

The diabetic rats showed a significant change in the urine (P < 0.001) and serum (P < 0.01) constituents such as albumin, creatinine, urea nitrogen and glycated hemoglobin. In addition, the serum lipid profile of the diabetic rats were altered significantly (P < 0.05) compared to that of the control rats. However, the diabetic rats supplemented with aged garlic extract restored all these biochemical changes. The efficacy of the extract was substantiated by the histopathological changes in the kidney.

Conclusion:

From our results, we conclude that aged garlic extract has the ability to ameliorate kidney damage in diabetic rats and the renoprotective effect of AGE may be attributed to its anti-glycation and hypolipidemic activities.KEY WORDS: Aged garlic extract, anti-glycation, diabetes, diabetic nephropathy, hypolipidemic, renoprotective