Resveratrol Attenuates Copper and Zinc Homeostasis and Ameliorates Oxidative Stress in Type 2 Diabetic Rats

Diabetes is a common metabolic disorder characterized by elevated blood glucose level. Trace element homeostasis causes disturbances in diabetes due to hyperglycemia. Superoxide dismutase (SOD), an antioxidant enzyme, contains zinc and copper ions as its cofactors. Defects in SOD level and activity have been observed in diabetes. Resveratrol (RSV) has displayed hypoglycemic effects and is proven to improve oxidative stress. The aim of the present study was to examine the possible effects of RSV on blood glucose level, serum copper and zinc levels, SOD, and a number of other oxidative markers in type 2 diabetic rats. Diabetes was induced in male Wistar rats with administration of streptozotocin and nicotine amide. The studied groups containing six animals per group were as follows: group 1 normal control group; group 2 diabetic control group; groups 3, 4, and 5 diabetic rats that received 1, 5, and 10 mg/kg body weight of RSV, respectively for 30 days. Serum glucose, copper, zinc, SOD activity, total oxidant status (TOS) as well as thiol groups were all measured. Blood glucose in RSV treated groups significantly decreased. Similarly, copper significantly decreased in diabetic groups treated with RSV. Treatment with 10 mg/kg RSV resulted in significantly increased serum zinc. Furthermore, Cu/Zn ratio was observed to decrease in treated groups compared with untreated diabetic control group. RSV treated groups revealed an increased level of SOD activity as well as improved oxidative status. In summary, the results showed that RSV has potential hypoglycemic effect, attenuates trace element homeostasis, and consequently increases SOD activity level.     

Hydroalcoholic Seed Extract of Coriandrum sativum (Coriander) Alleviates Lead-Induced Oxidative Stress in Different Regions of Rat Brain

Lead exposure is known to cause apoptotic neurodegeneration and neurobehavioral abnormalities in developing and adult brain by impairing cognition and memory. Coriandrum sativum is an herb belonging to Umbelliferae and is reported to have a protective effect against lead toxicity. In the present investigation, an attempt has been made to evaluate the protective activity of the hydroalcoholic extract of C. sativum seed against lead-induced oxidative stress. Male Wistar strain rats (100–120 g) were divided into four groups: control group: 1,000 mg/L of sodium acetate; exposed group: 1,000 mg/L lead acetate for 4 weeks; C. sativum treated 1 (CST1) group: 250 mg/kg body weight/day for seven consecutive days after 4 weeks of lead exposure; C. sativum treated 2 (CST2) group: 500 mg/kg body weight/day for seven consecutive days after 4 weeks of lead exposure. After the exposure and treatment periods, rats were sacrificed by cervical dislocation, and the whole brain was immediately isolated and separated into four regions: cerebellum, hippocampus, frontal cortex, and brain stem along with the control group. After sacrifice, blood was immediately collected into heparinized vials and stored at 4 °C. In all the tissues, reactive oxygen species (ROS), lipid peroxidation products (LPP), and total protein carbonyl content (TPCC) were estimated following standard protocols. An indicator enzyme for lead toxicity namely delta-amino levulinic acid dehydratase (δ-ALAD) activity was determined in the blood. A significant (p?<?0.05) increase in ROS, LPP, and TPCC levels was observed in exposed rat brain regions, while δ-ALAD showed a decrease indicating lead-induced oxidative stress. Treatment with the hydroalcoholic seed extract of C. sativum resulted in a tissue-specific amelioration of oxidative stress produced by lead.     

Fustin ameliorates hyperglycemia in streptozotocin induced type-2 diabetes via modulating glutathione/Superoxide dismutase/Catalase expressions,suppress lipid peroxidation and regulates histopathological changes

Streptozotocin (STZ) 60 mg/kg, i.p.-induced diabetes in rat’s results into hyperglycemia, impaired oxidative stress, lipid profile, insulin levels and changes in body weight. Treatment with antihyperglycemics and antioxidants are accounted to produce favorable effect in this paradigm. Fustin, a flavonoid derived from Rhus verniciflua, extract of Rhus verniciflua reported to exhibit anti-hyperglycemic, antioxidant, anti-microbial, anti-arthritic effects, anti-obesity effects, antiplatelet effects and anti-cancer effects. However, no evidence is existing on effect of fustin on STZ-induction diabetes. Thus, we evaluated its effects against diabetes in STZ-induced rodents. Blood glucose, Insulin, lipid peroxidation (MDA), superoxide dismutase (SOD), catalase activity (CAT), glutathione (GSH) and lipid profile levels was assessed. After 30 days diabetes induction rodents showed a severe increased blood sugar level, MDA, high density lipid and decreased cholestrol, triglyceride, GSH, SOD, CAT, respectively.Oppositely, treatment with fustin (50–100 mg/kg/p.o., two times daily, 30 days) enhanced blood glucose, lipid profile levels Insulin. Meanwhile, reduced MDA and enhanced GSH, SOD, and CAT in diabetic rats. Glibenclamide 5 mg/kg/p.o. also enhanced diabetes-induced complications and decreased oxidative stress. Further histopathology of pancreas confirms the protective effect fustin in STZ-induction diabetes in animals. In conclusion, the study revealed treatments with fustin avoid the changes in body weight, blood glucose, lipid profile and oxidative stress. As a results of these finding may lead to the growth of a choice of medicine for hyperglycemic in the future.     

Effects of pycnogenol treatment on oxidative stress in streptozotocin-induced diabetic rats

Free radicals and oxidative stress have been implicated in the etiology of diabetes and its complications. This in vivo study has examined whether subacute administration of pycnogenol, a French pine bark extract containing procyanidins that have strong antioxidant potential, alters biomarkers of oxidative stress in normal and diabetic rats. Diabetes was induced in female Sprague-Dawley rats by a single injection of streptozotocin (90 mg/kg body weight, ip), resulting (after 30 days) in subnormal body weight, increased serum glucose concentrations, and an increase in liver weight, liver/body weight ratios, total and glycated hemoglobin, and serum aspartate aminotransferase activity. Normal and diabetic rats were treated with pycnogenol (10 mg/kg body weight/day, ip) for 14 days. Pycnogenol treatment significantly reduced blood glucose concentrations in diabetic rats. Biochemical markers for oxidative stress were assessed in the liver, kidney, and heart. Elevated hepatic catalase activity in diabetic rats was restored to normal levels after pycnogenol treatment. Additionally, diabetic rats treated with pycnogenol had significantly elevated levels of reduced glutathione and glutathione redox enzyme activities. The results demonstrate that pycnogenol alters intracellular antioxidant defense mechanisms in streptozotocin-induced diabetic rats.     

Obtusifolin Treatment Improves Hyperlipidemia and Hyperglycemia: Possible Mechanism Involving Oxidative Stress

Clinical research has confirmed the efficacy of several plant extracts in the modulation of oxidative stress associated with hyperlipidemia and hyperglycemia induced by obesity and diabetes. Findings indicate that obtusifolin has antioxidant properties. The aim of this study was to evaluate the possible protective effects of obtusifolin against oxidative damage in diabetic hyperlipidemia and hyperglycemia. In this study, the rats were divided into the following groups with eight animals in each: control, untreated diabetic, three obtusifolin (10, 30, and 90 mg/kg/day)-treated diabetic groups. Diabetes was induced by streptozotocin (STZ) in rats. STZ was injected intraperitoneally at a single dose of 60 mg/kg for diabetes induction. Obtusifolin (intraperitoneal injection) was administered 3 days after STZ administration; these injections were continued to the end of the study (4 weeks). At the end of the 4-week period, blood was drawn for biochemical assays. In order to determine the changes of cellular antioxidant defense systems, antioxidant enzymes including glutathione peroxidase (GPx), superoxide dismutase (SOD), and catalase (CAT) activities were measured in serum. Moreover, we also measured serum nitric oxide (NO) and serum malondialdehyde (MDA) levels, markers of lipid peroxidation. STZ-induced diabetes caused an elevation (P < 0.001) of blood glucose, MDA, NO, total lipids, triglycerides and cholesterol, with reduction of GSH level and CAT and SOD activities. The results indicated that the significant elevation in the blood glucose, MDA, NO, total lipids, triglycerides and cholesterol; also the reduction of glutathione level and CAT and SOD activity were ameliorated in the obtusifolin-treated diabetic groups compared with the untreated groups, in a dose-dependent manner (P < 0.05, P < 0.01, P < 0.001). These results suggest that obtusifolin has antioxidant properties and improves chemically induced diabetes and its complications by modulation of oxidative stress.     

Influence of vanadium supplementation on oxidative stress factors in the muscle of STZ-diabetic rats

In recent years, the role of free radical damage consequent to oxidative stress is widely discussed in diabetic complications. In this aspect, the protection of cell integrity by trace elements is a topic to be investigated. Vanadium is a trace element believed to be important for normal cell function and development. The aim of the present study was to investigate the effect of vanadyl sulfate supplementation on the antioxidant system in the muscle tissue of diabetic rats. Diabetes was induced by intraperitoneal injection of streptozotocin (STZ, 65 mg/kg body weight) to male Swiss albino rats. The rats were randomly divided into 4 groups: Group I, control; Group II, vanadyl sulfate control; Group III, STZ-diabetic untreated; Group IV, STZ-diabetic treated with vanadyl sulfate. Vanadyl sulfate (100 mg/kg) was given daily by gavage for 60 days. At the last day of the experiment, rats were killed, muscle tissues were taken, homogenized in cold saline to make a 10% (w/v) homogenate. Body weights and blood glucose levels were estimated at 0, 30 and 60th days. Antioxidant enzymes, superoxide dismutase (SOD), catalase (CAT), glutathione reductase (GR), glutathione peroxidase (GPx), glutathione-S-transferase (GST), as well as carbonic anhydrase (CA), myeloperoxidase (MPO) activities and protein carbonyl content (PCC) were determined in muscle tissue. Vanadyl sulfate administration improved the loss in body weight due to STZ-induced diabetes and decreased the rise in blood glucose levels. It was shown that vanadium supplementation to diabetic rats significantly decrease serum antioxidant enzyme levels, which were significantly raised by diabetes in muscle tissue showing that this trace element could be used as preventive for diabetic complications.     

Silymarin regulates the cytochrome P450 3A2 and glutathione peroxides in the liver of streptozotocin-induced diabetic rats

This study aimed to investigate the protective and regulatory effects of silymarin (SMN) and melatonin (MEL) on streptozotocin (STZ)-induced diabetic changes in cytochrome P450 3A2 (CYP 3A2) and glutathione peroxidase (GPX) expression and antioxidant status in the liver. Male Wistar rats were divided into five groups, including: control (C), untreated diabetic animals (D), SMN-treated diabetics (S, 50 mg/kg, orally), MEL-treated diabetics (M, 10 mg/kg, i.p.), and SMN plus MEL-treated diabetics (S+M). Diabetes was induced by a single intraperitoneal injection of STZ (50 mg/kg). The blood glucose level, daily urinary volume and body weight changes were measured. After the 28 days treatment period, antioxidant status was analyzed by means of the determination of malondialdehyde (MDA) content, nitric oxide (NO) and total thiol molecules (TTM) levels in the liver. The glycogen depletion in the liver was examined by histochemical staining. The CYP 3A2 and GPX expression at mRNA level was determined using RT-PCT technique. SMN and MEL both individually or in combination prevented from diabetes-induced weight loss and lowered daily urinary volume significantly (p<0.05). None of the test compounds could lower the blood glucose level significantly (p>0.05). Both SMN and MEL could convert the diabetes induced elevated levels of MDA and NO and the diabetes-reduced TTM content to the control level. Moreover, the diabetes-up regulated CYP 3A2 and down regulated GPX, returned to normal values after SMN treatment. Histochemical and histopathological examinations revealed that the diabetes-induced glycogen-depletion and single cell necrosis markedly improved with the SMN and SMN plus MEL treatment. Our data suggest that the STZ-induced diabetes in addition of disturbing the antioxidant status, alters the expression levels of CYP 3A2 and GPX. Moreover, the SMN and SMN plus MEL treatment was able to normalize both the antioxidant status and the expression of CYP 3A2 and GPX in the liver of diabetic rats.     

Comparative and combined effect of chlorogenic acid and tetrahydrocurcumin on antioxidant disparities in chemical induced experimental diabetes

The present study evaluates the combined effect of tetrahydrocurcumin and chlorogenic acid on oxidative stress in streptozotocin–nicotinamide-induced diabetic rats. Rats were rendered diabetic by a single intraperitoneal injection (i.p) of streptozotocin (45 mg/kg BW), 15 min after an i.p injection of nicotinamide (110 mg/kg BW). The levels of fasting plasma glucose and insulin were estimated. As an index of oxidative stress, the levels of enzymic antioxidants and lipid peroxidation products were analyzed in liver and kidney. Diabetic rats showed an increase in the levels of fasting plasma glucose, lipid peroxidative products such as thiobarbituric acid reactive substances and lipid hydroperoxides and a decrease in plasma insulin, and enzymic antioxidants viz., superoxide dismutase, catalase, glutathione peroxidase and glutathione-S-transferase. Combined administration of tetrahydrocurcumin (80 mg/kg BW) and chlorogenic acid (5 mg/kg BW) to diabetic rats for 45 days, reversed the biochemical changes to near normal. The above findings were supported by histological observations of the liver and kidney. Together the present study clearly reflects that combined dosage of tetrahydrocurcumin and chlorogenic acid augments enzymic antioxidants with a concomitant decrease in lipid peroxidation and protects against streptozotocin–nicotinamide-induced type 2 diabetes in experimental rats.     

Beneficial effects of Phellodendri Cortex extract on hyperglycemia and diabetic nephropathy in streptozotocin-induced diabetic rats

This study investigated the effect of Phellodendri Cortex extract on hyperglycemia and diabetic nephropathy in streptozotocin-induced diabetic rats. Male Sprague-Dawley rats were divided into normal control (NC), diabetic control (DC), and diabetic treatment with Phellodendri Cortex extract (DP). Over a 4-week experimental period, Phellodendri Cortex extract was administered orally at 379 mg/kg BW/day. The final fasting serum glucose level, urine total protein level, and relative left kidney weight in the DP group were significantly lower than the DC group. Renal XO and SOD activities in the DP group were significantly lower than the DC group and renal CAT activity in the DP group was significantly higher than the DC group. Tubular epithelial change was reduced in the DP group compared to the DC group. These results indicated that Phellodendri Cortex can reduce glucose level and prevent or retard the development of diabetic nephropathy in streptozotocin-induced diabetic rats.     

Cytoprotective and anti-diabetic effects of Derris reticulata aqueous extract

The current study was aimed to investigate pancreatic protective and anti-diabetic activities of the aqueous extract of Derris reticulata stem. First, we evaluated a cytoprotective potential of D. reticulata extract on alloxan-induced damage in vitro. Treatment with D. reticulata extract at the doses of 250 and 500 μg/ml significantly increased cell viability of the pancreatic β-cell line RINm5F after exposure of alloxan. The anti-hyperglycemic activity of D. reticulata extract was further studied in alloxan-induced diabetic rats. A significant reduction in blood glucose level along with an increase in body weight was observed in diabetic rats treated with D. reticulata extract at 250 mg/kg body weight for 15 days. Serum aspartate transaminase and alanine transaminase levels were also significantly decreased compared to diabetic control rats. In accordance with in vitro cytoprotective effect, histopathological examination revealed that pancreatic islet cells of the extract-treated diabetic rat were less damage than those of the untreated diabetic group. In order to find another possible mechanism of action underling hypoglycemic activity, the effect on glucose absorption was examined using everted sac jejunum. The results showed that D. reticulata extract suppressed glucose absorption from small intestine. To corroborate safety use of D. reticulata extract, acute oral toxicity was also conducted in rats. Our results showed that none of the tested doses (250, 500, 1,000, and 2,000 mg/kg) induced signs of toxicity or mortality after administration of the extract. The results suggested that D. reticulata extract possess anti-diabetic activity, which resulting from its pancreatic cytoprotective effect and inhibition of intestinal glucose absorption.     

Ascorbic acid is superior to silymarin in the recovery of ethanol-induced inflammatory reactions in hepatocytes of guinea pigs

Both oxidative stress and inflammatory reactions play a major role in alcoholic liver fibrosis. We evaluated the efficacy of ascorbic acid (AA) and silymarin in the regression of alcohol-induced inflammation in hepatocytes of guinea pigs (Cavia porcellus). Animals were administered with ethanol at a daily dose of 4 g/kg body weight (b.wt) for 90 days. On the ninety-first day, ethanol administration was stopped and animals were divided into alcohol abstention group and silymarin- (25 mg/100 g b.wt) and AA- (25 mg/100 g b.wt) supplemented groups and maintained for 30 days. There was a significant increase in the activities of alanine aminotransferase, aspartate aminotransferase, and γ-glutamyl transpeptidase in the serum of the ethanol group. The intracellular reactive oxygen species (ROS) and expressions of cytochrome P4502E1 and nuclear factor κB1, tumor necrosis factor-α, and transforming growth factor-β₁ in hepatocytes were significantly increased in ethanol group. The fibrotic markers α-smooth muscle actin and α ₁(I) collagen and activity of cytotoxicity marker caspase-3 were significantly increased and AA content was significantly reduced in hepatocytes of alcohol-treated guinea pigs. But the AA and silymarin supplementation significantly reduced these changes in comparison with alcohol abstention group. AA could induce greater reduction of inflammatory and fibrotic markers in hepatocytes than silymarin. This indicates that AA is superior to silymarin in inhibiting intracellular ROS generation and thereby reducing the ethanol-induced inflammation in hepatocytes.     

Antihyperglycemic and antioxidant effect of hydroethanolic extract of Butea monosperma bark in diabetic mice

The antihyperglycemic, antihyperlipidemic and antioxidative properties of hydroethanolic extract of Butea monosperma bark were investigated in alloxan-induced diabetic mice. Alloxan administration resulted in higher blood glucose level and reduced hepatic glycogen content as compared to normal animals. Besides, serum lipid profile parameters such as total cholesterol (TC), triglyceride (TG), low density lipoprotein (LDL) and very low density lipoprotein (VLDL) cholesterol were also found to be significantly elevated, whereas the level of high density lipoprotein (HDL) cholesterol was markedly reduced in diabetic animals. Oxidative damage in the tissues of diabetic mice was evidenced by a marked increase in the level of thiobarbituric acid reactive substances (TBARS), distinct decrease in reduced glutathione (GSH) content and declined activity of antioxidant enzymes, such as superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GSH-Px). The daily treatment of diabetic animals with crude extract of B. monosperma bark (300 mg kg(-1)) for 45 days significantly lowered blood glucose level and elevated hepatic glycogen content, bringing the values close to those observed in normal control and glibenclamide-treated diabetic mice. Furthermore, the level of various lipid profile parameters was also reversed towards normal. TBARS and GSH also restored towards normal and the declined activity of antioxidant enzymes in diabetic animals was also normalized in crude extract administered mice, thus indicating the antioxidant efficacy of the drug in diabetes-induced oxidative damage. Significant antihyperglycemic and antioxidant potential of the crude extract of B. monosperma bark indicated that it may find use in the management of diabetes and resultant oxidative stress.     

Superoxide dismutase, catalase and glutathione peroxidase activities in the brain of streptozotocin induced diabetic rats

Brain antioxidant enzymes, superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPX) levels were studied in the brains of early diabetic (72 hr) and long term diabetic (one month) rats. Diabetes was induced by injecting streptozotocin (50 mg/kg, i.p.) in citrate buffer. One group of diabetic rats was treated with insulin (1U/day/animal). The results indicate that early diabetic rats exhibit increased SOD and CAT activities with no alteration in the GPX activity. On the contrary, increased CAT decreased GPX activities with no alteration in the SOD activity, was noted in the long-term Diabetic rats. Insulin treatment reversed these alterations in both the groups. It can be concluded that, in diabetic condition antioxidant enzyme levels are elevated and insulin treatment attenuated these changes. Hence, diabetes mellitus, if left untreated, may initiate degenerative processes and other CNS complications due to accumulation of oxidative free radicals.     

Hypoglycemic and hepatoprotective activity of Rosmarinus officinalis extract in diabetic rats

The present study examined the effect of water extract (200 mg/kg body weight) of Rosmarinus officinalis L. in streptozotocin (STZ)-induced diabetic rats for 21 days. The hepatoprotective effects were investigated in the liver tissues sections. There was a significant increase in serum liver biochemical parameters (aspartate aminotransferase, alanine transaminase, and alkaline phosphatase), accompanied by a significant decrease in the level of total protein and albumin in the STZ-induced rats when compared with that of the normal group. The high-dose treatment group (200 mg/kg body wt) significantly restored the elevated liver function enzymes near to normal. This study revealed that rosemary extracts exerted a hepatoprotective effect. The results indicate that the extract exhibits the protective effect on tissues and prove its potentials as an antidiabetic agent.     

Ganoderma lucidum polysaccharides supplementation attenuates exercise-induced oxidative stress in skeletal muscle of mice

The present study was designed to determine the effects of Ganoderma lucidum polysaccharides (GL-PS) on exhaustive exercise-induced oxidative stress in skeletal muscle tissues of mice. The mice were divided into four groups (three GL-PS administered groups and the control group). The control group was administered with distilled water and GL-PS administered groups were administered with GL-PS (50, 100 and 200 mg/kg body weight per day). After 28 days, the mice performed an exhaustive swimming exercise, along with the determination of superoxide dismutase (SOD), glutathione peroxidase (GPX), catalase (CAT) activities and malondialdehyde (MDA) levels in the skeletal muscle of mice. The results showed that GL-PS could increase antioxidant enzymes activities and decrease the MDA levels in the skeletal muscle of mice. This study provides strong evidence that GL-PS supplementation possessed protective effects against exhaustive exercise-induced oxidative stress.     

Comparative Study of Antidiabetic Activity and Oxidative Stress Induced by Zinc Oxide Nanoparticles and Zinc Sulfate in Diabetic Rats

In the current study, antidiabetic activity and toxic effects of zinc oxide nanoparticles (ZnO) were investigated in diabetic rats compared to zinc sulfate (ZnSO₄) with particular emphasis on oxidative stress parameters. One hundred and twenty male Wistar rats were divided into two healthy and diabetic groups, randomly. Each major group was further subdivided into five subgroups and then orally supplemented with various doses of ZnO (1, 3, and 10 mg/kg) and ZnSO₄ (30 mg/kg) for 56 consecutive days. ZnO showed greater antidiabetic activity compared to ZnSO₄ evidenced by improved glucose disposal, insulin levels, and zinc status. The altered activities of erythrocyte antioxidant enzymes as well as raised levels of lipid peroxidation and a marked reduction of total antioxidant capacity were observed in rats receiving ZnO. ZnO nanoparticles acted as a potent antidiabetic agent, however, severely elicited oxidative stress particularly at higher doses.     

Citrus medica L. cv Diamante (Rutaceae) peel extract improves glycaemic status of Zucker diabetic fatty (ZDF) rats and protects against oxidative stress

This study aimed to investigate the antidiabetic, antilipidaemic and antioxidant activities of Citrus medica cv Diamante (Rutaceae) hydroalcoholic (CD) peel extract in Zucker diabetic fatty (ZDF) rats. The ability of CD to protect against oxidative stress was investigated by using different in vitro assays and in vivo by using the reactive oxygen metabolites-derived compounds (d-ROMs) test and the biological antioxidant potential test (BAP). Two different doses of CD extract (300 and 600?mg/kg/die) were administered at ZDF rats for 4 weeks. CD reduced cholesterol and triglycerides levels. A dose-dependent effect on body weight and serum glucose levels was observed. A decrease of d-ROMs and an increase of BAP were recorded by using the dose of 600?mg/kg. The extract inhibited lipid peroxidation (IC₅₀ value of 0.23?mg/ml). These findings suggest as an efficient phytotherapeutic approach in combating hyperlipidaemic and hyperglycaemic disorders.     

Oral administration of levan polysaccharide reduces the alloxan-induced oxidative stress in rats

This study aimed to evaluate the effect of a polysaccharide named levan, which was produced by new isolated bacteria, on oxidative stress and hyperglycemia in alloxan-induced diabetic rats. Levan polysaccharide was given in drinking water for 60 days at a daily dose equivalent to 2%. The oral administration of levan in diabetic rats caused a decrease in glucose level in plasma and an increase of superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPX) activities in both pancreas and liver. Furthermore, a protective action against hepatic and pancreatic toxicity in diabetic rats was clearly observed. Furthermore, a significant decrease in hepatic and pancreatic indices toxicity was observed, i.e., alkalines phosphatases (ALP), aspartate and lactate transaminases (AST and ALT), lactate deshydrogenases (LDH) activities and the thiobarbituric acid-reactive substances (TBARs). These beneficial effects of levan were confirmed by histological findings in hepatic and pancreatic tissues of diabetic rats. This study demonstrates for the first time that levan is efficient in inhibiting hyperglycemia and oxidative stress induced by diabetes and suggests that administration of levan may be helpful in the prevention of diabetic complications associated with oxidative stress.     

Effects of Andrographis paniculata (Burm. F.) Extract on Diabetic Nephropathy in Rats

Background:Hyperglycemia and accumulation of advanced glycation end products (AGEs) play a significant role in the development of diabetic nephropathy. Andrographis paniculata (AP) is a plant with high flavonoid content with the potential to suppress oxidative stress activity in cells and tissue. This study was aimed to investigate the role of Andrographis paniculata extract (APE) in protecting kidney damage due to the formation of AGEs in the renal glomerulus in diabetic rats.Methods:A total of 30 male Sprague Dawley rats were randomly divided into five groups as follows: normal control group, streptozocin (STZ) induced diabetic group, STZ-induced diabetic group with AP extract (100 mg/kg BW), STZ-induced diabetic rats with AP extract (200 mg/kg BW), and STZ-induced diabetic rats with APE (400 mg/ kg BW). Blood glucose levels were measured before treatment and after treatment. Serum and urine parameters were determined. Antioxidant enzymes and lipid peroxide levels were determined in the kidney along with histopathological examination.Results:The finding of this study showed that treatment APE at the dose of 200 mg/kg and 400 mg/kg ameliorated kidney hypertrophy index. SOD, catalase, and GSH activities significantly decreased in the kidney of STZ-diabetic rats compared to the normal control rats. Treatment with APE significantly decreased malondialdehyde level at the dose of 200 and 400 mg/kg BW.Conclusion:This study revealed evidence for improving diabetic retinopathy in male rats treated with Andrographis paniculata extract. APE significantly decreased oxidative stress activities in kidney of diabetic rats.Key Words: Andrographis, Diabetic Nephropathies, Streptozocin, Rats, Oxidative Stress     

Neuroprotective role of lipoic acid against acute toxicity of N-acetylaspartic acid

N-Acetylaspartic acid (NAA) accumulates in Canavan disease, a severe inherited neurometabolic disorder clinically characterized by mental retardation, hypotonia, macrocephaly, and seizures. The mechanisms of brain damage in this disease remain poorly understood. Recent studies developed by our research group showed that NAA induces oxidative stress in vitro and in vivo in cerebral cortex of rats. Lipoic acid is considered as an efficient antioxidant which can easily cross the blood–brain barrier. Considering the absence of specific treatment to Canavan disease, this study evaluates the possible prevention of the oxidative stress promoted by NAA in vivo by the antioxidant lipoic acid to preliminarily evaluate lipoic acid efficacy against pro-oxidative effects of NAA. Fourteen-day-old Wistar rats received an acute administration of 0.6 mmol NAA/g body weight with or without lipoic acid (40 mg/kg body weight). Catalase (CAT), glutathione peroxidase (GPx), and glucose 6-phosphate dehydrogenase activities, hydrogen peroxide content, thiobarbituric acid-reactive substances (TBA-RS), spontaneous chemiluminescence, protein carbonyl content, total antioxidant potential, and DNA–protein cross-links were assayed in the cerebral cortex of rats. CAT, GPx activities, and total antioxidant potential were significantly reduced, while hydrogen peroxide content, TBA-RS, spontaneous chemiluminescence, and protein carbonyl content were significantly enhanced by acute administration of NAA. Those effects were all prevented by lipoic acid pretreatment. Our results clearly show that lipoic acid may protect against the oxidative stress promoted by NAA. This could represent a new therapeutic approach to the patients affected by Canavan disease.