Rimi Shukla

Antioxidant status, lipid peroxidation and nitric oxide end products in patients of type 2 diabetes mellitus with nephropathy.

OBJECTIVES Oxidative stress is considered to be a unifying link between diabetes mellitus (DM) and its complications including nephropathy. The aim of the present study was to evaluate oxidative stress status in Asian Indian patients of type 2 DM with nephropathy. DESIGN AND METHODS Serum levels of malondialdehyde (MDA) and nitric oxide end products (nitrite and nitrate), activities of erythrocyte superoxide dismutase (SOD), catalase (CAT) and reduced glutathione (GSH) content were estimated in controls, patients of type 2 DM without nephropathy (group 1) and with nephropathy (group 2). RESULTS Serum MDA concentration was significantly high in both the groups of diabetic patients as compared to controls, (p < 0.05), with group 2 having a significantly higher value than group 1 (p < 0.05). Significantly elevated serum nitrite levels were found in diabetic patients as compared to controls (p < 0.001), however, no significant difference was found between group 1 and group 2. Moreover, serum nitrate as well as nitrite + nitrate levels were significantly higher in group 2 as compared to controls (p < 0.05). Activity of erythrocyte SOD and CAT was significantly reduced in both groups as compared to controls (p < 0.001) with catalase activity in group 2 being significantly lower than group 1 (p < 0.05). Erythrocyte GSH content was significantly lower in group 2 as compared to controls (p < 0.05) and group 1 (p < 0.05). CONCLUSIONS Results of the present study indicate that oxidative stress is increased and antioxidant defenses are compromised in type 2 DM. These derangements are of a higher magnitude in patients of type 2 DM with nephropathy.

Association of biomarkers of inflammation and oxidative stress with the risk of chronic kidney disease in Type 2 diabetes mellitus in North Indian population

Chronic kidney disease (CKD) is a major cause of morbidity and mortality worldwide. It results from diverse etiologies, diabetes being a frontrunner amongst them. Type 2 diabetes mellitus (DM) is being increasingly recognized as a proinflammatory state with increased oxidative stress which enormously increases the risk of micro and macro vascular diseases. This study was planned to explore the possible association between tumor necrosis factor-alpha (TNF-α), urinary monocyte chemoattractant protein-1 (uMCP-1), high-sensitivity C-reactive protein (hsCRP) and parameters of oxidative stress in patients with Type 2 diabetes mellitus (DM) and diabetic chronic kidney disease (DM-CKD). Fifty patients each were recruited in DM, DM-CKD and healthy control groups. Plasma TNF-α, hsCRP and uMCP-1 levels as inflammatory mediators were measured by ELISA, reduced glutathione (GSH), ferric reducing ability of plasma (FRAP) as parameters of antioxidant activity and malondialdehyde (MDA) as marker of oxidative stress, were measured spectrophotometrically. Plasma TNF-α, hsCRP and uMCP-1 were significantly higher in DM-CKD compared to DM and healthy controls. Lipid peroxidation, measured as MDA was significantly higher in patients with DM-CKD as compared to patients with DM and healthy controls. Further, antioxidant capacity of blood measured as FRAP and GSH was found to be significantly lower in patients with DM and DM-CKD as compared to healthy controls (p<0.001). Plasma TNF-α and uMCP-1 showed a significant positive correlation with HbA1c (r=0.441, 0.643), hsCRP (r=0.400, 0.584) and MDA (r=0.423, 0.759) and significant negative correlation with GSH (R=-0.370, -0.800) and FRAP (r=-0.344, -0.684) Increased inflammatory markers viz. TNF-α, hsCRP and uMCP-1 and markers of oxidative stress i.e. increased MDA and decreased GSH and FRAP in DM-CKD suggest an important role of inflammation and oxidative stress in the pathogenesis of renal damage in diabetic patients.

Hypolipidemic effect of water extract ofFicus bengalensis in alloxan induced diabetes mellitus in rabbits

Hypolipidemic effect of the water extract of the bark ofFicus bengalensis was investigated in alloxan induced diabetes mellitus in rabbits. Treatment for one month (50 mg/kg body weight/day) brought down the level of total serum cholesterol (TC) in subdiabetic and diabetic rabbits (five in each group) from 82±11 mg% and 118±10.6 mg% to 42.7±3.1 mg% and 51.7±4.7 mg% respectively. Low density lipoprotein cholesterol and very low density lipoprotein cholesterol values came down from 34±10 mg% and 95±24 mg% to 16±3 mg% and 29±4 mg% in subdiabetic and diabetic rabbits. Triacylglycerol level before treatment was 121±21.6 mg% and 416±70 mg% in subdiabetic and diabetic rabbits. Treatment brought it down to 45±5 mg% and 81±27.5 mg%. Glycosylated hemoglobin was brought down from 2.1±0.3% to 1.5±0.1% in subdiabetic group and from 4.28±0.5% to 2±0.3% in diabetic group, indicating that treatment with water extract effectively controlled blood sugar.After treatment with water extract serum lipid values were nearly equal to those in healthy controls (normal) in subdiabetic rabbits, while in diabetic group, the values were only slightly above those of normal.

Ameliorative effect of Withania coagulans on dyslipidemia and oxidative stress in nicotinamide–streptozotocin induced diabetes mellitus

Present study aims to evaluate the effect of Withania coagulans fruit (aqWC) on diabetic-dyslipidemia and antioxidant/oxidant status in DM. Diabetic animals were treated with aqWC at a dose of 250 mg/kg bw for 30 days. Lipid profile, MDA, GSH, SOD, FRAP, HMG CoA reductase and acetyl CoA carboxylase activities were estimated in blood and tissues. Total cholesterol, TAG and LDL were significantly elevated whereas HDL was decreased in diabetic animals (p<0.05), simultaneously the lipid content and HMG CoA reductase activities were also increased, whereas acetyl CoA carboxylase activity decreased significantly in tissues of diabetic animals. MDA was increased and antioxidants such as SOD, GSH and FRAP decreased significantly in DM (p<0.05). Oral administration of aqWC to diabetic animals produced significant improvement in serum lipid profile and tissue lipid content. Activity of HMG CoA reductase decreased, whereas acetyl CoA carboxylase activity increased significantly in tissues after aqWC treatment. Administration of aqWC to diabetic animals also showed significant increase in antioxidant levels i.e., GSH, SOD, FRAP and reduced level of MDA in blood and tissue homogenates as compared to diabetic controls (p<0.05). These results suggest that aqWC treatment improved lipid profile and decreased oxidative stress in diabetes mellitus.

Hypocholesterolemic effect of water extract of the bark of banyan tree,Ficus bengalensis

The hypocholesterolemic effect of the water extract of the bark ofFicus bengalensis was investigated in 3 groups of rabbits, 5 in each group. Group 1 rabbits served as healthy controls and were fed with groundnut oil 1 ml/kg body wt. (bw) for five weeks. Groups 2 and 3 were made hypercholesterolemic by feeding orally cholesterol suspended in groundnut oil (1 ml/kg bw) at a dose of 100 mg/kg bw/day. Group 2 animals (untreated) continued to get the same amount of cholesterol for another four weeks. Group 3 animals received water extract of the bark (50 mg/kg bw/day) in addition to cholesterol as above. At the end of the 5th week, water extract not only prevented the elevation of serum cholesterol in the treated animals (Group 3) but also brought down its level to 160±14 mg% as compared to untreated animals (Group 2) 290±42 mg%. There was improvement in other parameters of lipid profile namely HDL & LDL+VLDL cholesterol and triacylglycerol.

Association of Tumor Necrosis Factor (TNF) promoter polymorphisms with plasma TNF-α levels and susceptibility to diabetic nephropathy in North Indian population

AIM The concept of diabetic nephropathy (DN) as a metabolic disease is now being replaced by chronic low-grade inflammatory disease. Tumor necrosis factor-alpha (TNF-α) is a proinflammatory cytokine which plays an important role in the pathogenesis and clinical outcome of DN. Therefore, this work was planned to evaluate the association of -863C/A (rs1800630) and -1031T/C (rs1799964) polymorphisms in TNF gene with plasma TNF-α levels and DN among subjects with type 2 diabetes (T2DM) in a population from North India. METHODS Age and sex matched 100 healthy controls (HC), 100 T2DM subjects without nephropathy (DM) and 100 subjects with DN were screened for above polymorphisms using the PCR-RFLP methods. Plasma TNF-α levels were measured by ELISA. Analysis of variance and logistic regression were used to associate individual polymorphisms with plasma TNF-α levels and DN. RESULTS The allelic frequencies of -863C/A were 0.86/0.14 in HC, 0.72/0.23 in DM and 0.84/0.16 in DN, and that of -1031T/C were 0.89/0.11 in HC, 0.95/0.05 in DM and 0.80/0.20 in DN. The carriers of -863A allele had significantly lower plasma TNF-α levels (p<0.05). The -863C/A (OR=0.439, 95% CI=0.244-0.789, p=0.006) and -1031T/C (OR=3.0, 95% CI=1.355-6.642, p=0.007) were strongly associated with risk of development of DN. CONCLUSIONS -863C/A was associated with low whereas -1031T/C with high TNF-α levels. The, results suggest that -863C/A polymorphism might be protective whereas -1031T/C may be associated with increased risk for DN in subjects with T2DM from North India.

Antidiabetic and antihyperlipidemic effects of the stem of Musa sapientum Linn. in streptozotocin-induced diabetic rats.

Background:  Musa sapientum Linn. is a herbaceous plant of the Musaceae family. It has been used in India for the treatment of gastric ulcer, hypertension, diarrhea, dysentery, and diabetes. The antidiabetic effect of the fruit, root, and flower has been demonstrated. The aim of the present study was to assess the antidiabetic and antihyperlipidemic effects of the stem of M. sapientum Linn.

Acute and chronic toxicity studies on partially purified hypoglycemic preparation from water extract of bark ofFicus bengalensis

Acute and chronic toxicity studies were conducted to assess toxicity of a partially purified preparation from the water extract of the bark ofFicus bengalensis, which was demonstrated in our earlier studies to have significant hypoglycemic and hypocholesteroiemic effect on alloxan induced, mild and severe diabetes in rabbits. LD50 of this preparation was found to be ∼1 gm/kg in rats when given orally. For chronic toxicity studies 3 doses of aqueous preparation were given to 3 groups of rats. First group received 5 times ED50 (50 mg/kg), second group 10 times ED50 (100 mg/kg) and the third group 15 times ED50 (150 mg/kg) for 3 months. Fourth group which served as control was given water. After three months, blood was collected for studying biochemical and hematological parameters. Blood glucose, serum cholesterol, liver and kidney function tests, haemoglobin, total and differential leukocyte count were determined. Animals were sacrificed and histopathological examination of liver, heart and kidneys was carried out. Results of the study showed that partially purified preparation fromFicus bengalensis is not toxic by all the above mentioned parameters.

Association of glutathione-S-transferase with patients of type 2 diabetes mellitus with and without nephropathy.

STATEMENTS OF THE PROBLEM Hyperglycemia induced oxidative stress is implicated as a contributor to the onset and progression of type 2 diabetes mellitus (T2DM) and its complications like diabetic nephropathy (DN). Glutathione-S-transferase (GST) is primarily involved in the neutralization of reactive oxygen species (ROS) by enzymatic conjugation with the scavenger peptide glutathione (GSH). Therefore, present study was aimed to evaluate the role of GST along with oxidative stress markers and their correlation in patients with Type 2 diabetes mellitus with and without nephropathy. METHODS This study comprised of 300 participants divided into three groups of 100 each: healthy controls (HC), T2DM without complications and DN. Plasma GST, malondialdehyde (MDA), reduced GSH levels and ferric reducing ability of plasma (FRAP) were estimated spectrophotometrically. RESULTS Highest GST levels was observed in T2DM which was significantly higher (p<0.05) as compared to DN and HC. However, GSH and FRAP levels were found to be significantly lowest whereas MDA levels were significantly highest in DN as compared to T2DM and HC. GST showed a significant negative correlation with GSH, FRAP and positive correlation with MDA in both patients groups. CONCLUSIONS Highest activity of GST in T2DM might be as a compensatory mechanism in response to oxidative stress. GST is found to have significant negative association with decreased GSH. Altered redox milieu in DN collectively conspire to increase the risk of renal damage in T2DM.

Genetic association of NAD(P)H quinone oxidoreductase (NQO1*2) polymorphism with NQO1 levels and risk of diabetic nephropathy.

Abstract NAD(P)H quinone oxidoreductase 1 (NQO1) catalyzes reactions having a cyto-protective effect against redox cycling and oxidative stress. A single base polymorphism (C/T) at nucleotide 609 of the NQO1 gene impairs the stability and function of its protein. Its role in the development of diabetic nephropathy (DN) has not been deciphered. Therefore, this study aimed to evaluate the association of NQO1*2 (rs1800566) polymorphism with plasma NQO1 levels and DN. This study screened 600 participants including healthy controls (HC), type 2 diabetes mellitus without complications (T2DM) and diabetic nephropathy (DN): 200 each for studying NQO1*2 gene polymorphism using the PCR-RFLP. Plasma NQO1 levels were measured by ELISA. Analysis of variance and logistic regression were used to evaluate the association of NQO1 polymorphism with plasma NQO1 levels and DN. The allelic frequencies of NQO1*1/NQO1*2 were 0.88/0.12 in HC, 0.765/0.235 in T2DM and 0.65/0.35 in DN. Carriers of the NQO1*2 allele had significantly lower plasma NQO1 levels (p<0.05) and revealed higher risk towards the development of DN (OR=1.717, p=0.010). NQO1*2 SNP is a functional polymorphism having a significant effect on NQO1 levels. Our results indicate that NQO1*2 genotype may increase susceptibility to DN in north Indian subjects with T2DM.