Evaluation of adenosine deaminase activity and lipid peroxidation levels in diabetes mellitus

There was increase in erythrocyte lipid peroxidation and adenosine deaminase (ADA) activity in red blood cells (RBC's), white blood cells (WBC's) and plasma, in 30 patients of confirmed diabetes mellitus, 10 each of insulin dependent diabetes mellitus (IDDM or type I), non-insulin dependent diabetes mellitus (NIDDM or type II) and diabetes with ketoacidosis when compared with 20 healthy individuals (controls). Glycosylated hemoglobin A1c%, plasma free fatty acid (FFA) and glycerol levels were also elevated in all the cases when compared with controls. The increase was more in diabetic ketoacidosis group. Significant positive correlations were seen between erythrocyte lipid peroxidation and ADA activities in RBC's, WBC's and plasma. It is suggested that decreased tissue adenosine levels due to increase in ADA activity, is related to the severity of hyperglycemia and lipid peroxidation in diabetes mellitus.     

RBC membrane composition in insulin dependent diabetes mellitus in context of oxidative stress

Glyco-oxidation is considered as a source of permanent, cumulative, oxidative damage to long lived proteins in ageing and in diabetes. Although RBC depends solely on glucose for energy purpose, hyperglycemic state glycosylates hemoglobin, creates oxidative stress and puts the cellular components at risk. In view of this, RBC membrane composition was analyzed in diabetic patients. The results were compared with healthy age and sex matched control groups. When RBC membrane components such as protein, sialic acid, phospholipids and cholesterol were determined in insulin dependent diabetes mellitus, a significant rise in phospholipids and cholesterol and significant fall in sialic acid and protein content was noted. RBC membrane composition showed pronounced alterations in insulin dependent diabetes mellitus. These changes were accompanied by higher levels of lipid peroxidation products like Malondialdehyde.     

Attenuation of oxidative stress in streptozotocin-induced diabetic rats by <Emphasis Type="Italic">Eucalyptus globulus</Emphasis>

In traditional medicine, Eucalyptus globulus (eucalyptus) was used for the treatment of diabetes mellitus. Hyperglycemia in diabetes has been associated with increased formation of reactive oxygen species (ROS) and oxidative damage to tissue compounds. The aim of this study was to evaluate the effects of eucalyptus in the diet (20 g/Kg) and drinking water (2.5 g/L) on lipid peroxidation, protein oxidation and antioxidant power in plasma and liver homogenate, as well as glycated-Hb (HbA_1C) of blood in streptozotocin-induced diabetic rats for a period of 4 weeks. Diabetes induced in rats by a single intraperitoneal injection of streptozotocin (STZ, 65 mg/Kg). At the end of the treatment period, the level of plasma glucose, plasma and liver malondialdehyde (MDA, the main product of lipid peroxidation), protein carbonyl (PC, one of the protein oxidation products) and HbA_1C increased and ferric reducing antioxidant power (FRAP) decreased in diabetic rats compared to normal rats. Eucalyptus administration for 4 weeks caused a significant decrease in the plasma glucose levels, plasma and liver MDA, PC and HbA_1C, also a concomitant increase in the levels of FRAP in diabetic treated rats. In conclusion, the present study showed that eucalyptus posses antioxidant activities. Eucalyptus probably restores antioxidant power, due to the improved hyperglycemia in streptozotocin-induced diabetic rats.     

Plasma MDA and antioxidant vitamins in diabetic retinopathy

Hyperglycemia and dyslipidemia in diabetes mellitus induce increased lipid peroxidation and peroxyl radical formation, an important mechanism in genesis of microangiopathy. We took up a study on oxidative stress, measured by plasma MDA and antioxidant vitamin status in type − 2 DM patients with and without retinopathy and compared them with a control non-diabetic group. Lipid peroxidation marker MDA was significantly elevated (p < 0.001) in both the diabetic groups whereas, serum vitamin E and vitamin C registered a significant fall (p<0.001) as compared to controls. Our correlation study revealed a significant positive association between plasma MDA with both fasting and 2hr post prandial plasma glucose (r=0.81, p < 0.001, r=0.92, p <0.001) suggesting the role of hyperglycemia in free radical production. Plasma MDA also depicted significant positive relation (p< 0.001) with all lipid parameters except serum HDLc pointing the role of dyslipidemia towards lipid peroxidation. Plasma MDA level was also found to be negatively correlated with both the vitamins (p<0.001, p<0.001) in the study group explaining their protective consumption in the oxidative process prevailing in diabetic retinopathy.     

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.     

Serum dehydroepiandrosterone and lipid peroxides in human volunteers of different age groups

The objective of the present study was to evaluate the changes in serum dehydroepiandrosterone (DHEA) and lipid peroxide levels during ageing in human subjects. Random blood samples were collected from a total of 128 apparently normal human volunteers of both sexes, whose age ranged between 21–70 years. The subjects were divided into groups of a decade years of age difference. Serum levels of dehydroepiandrosterone (DHEA), lipid peroxides as malondialdehyde (MDA), and insulin were analysed in all the subjects recruited in the study. In the present study there was decrease in serum DHEA levels with age (11.30 to 7.99 ng/ml). However the differences were significant only after 50 years up to 70 years. Serum MDA levels of these subjects were higher (3.91 to 4.74 ng/ml) as compared to the values reported earlier (2.64 to 3.94 ng/ml). The serum MDA levels also showed an increasing trend with age but the increase was significant only in the 40–50 years age group and values plateaud off at later ages. The MDA and DHEA levels in women in general were lower than in men and this could be due to female hormones, which are known to protect lipid against peroxidation. There was a significant negative correlation between age and DHEA (r=−0.311 P<0.05) and positive correction between MDA and age (r=+0.405 P<0.01). No significant differences were seen in serum insulin, albumin and total protein levels. These preliminary findings support the possible utility of DHEA and MDA as markers for chronological ageing.     

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.     

Comparison of lipid profile and antioxidant enzymes among south Indian men consuming coconut oil and sunflower oil

In this study, we compared the lipid profile and antioxidant enzymes of normal and diabetic subjects consuming two different types of oil as cooking medium. 70 normal, healthy subjects were taken as controls and 70 subjects with Type 2 diabetes were recruited in patient group. Each group was further subdivided into two subgroups of 35 subjects each, consuming coconut oil and sunflower oil respectively as cooking medium. Samples of blood were collected and analyzed for serum total cholesterol, triacylglycerols, and cholesterol in lipoprotein fractions. Total glutathione and glutathione peroxidase were measured in erythrocytes and superoxide dismutase in serum. Triacylglycerols, LDL and VLDL cholesterol levels were high in the diabetic subjects compared to the controls. Total glutathione and glutathione peroxidase values showed significant decrease in diabetic subjects as compared to the controls, while superoxide dismutase values showed significant difference between coconut oil consuming groups. Though lipid profile parameters and oxidative stress were high in Type 2 diabetic subjects compared to controls, no pronounced changes for these parameters were observed between the subgroups (coconut oil vs. sunflower oil).     

Effect of increasing duration of diabetes mellitus type 2 on glycated hemoglobin and insulin sensitivity

Non-insulin dependent diabetes mellitus (NIDDM) is the most rapidly growing chronic metabolic disorder in the world. With advancement in the age and duration of diabetes there is a gradual tendency for the level of blood sugar to rise along with a subsequent increase in the HbA1c as well as in the fasting insulin level. Whether this is an aging process or increased frequency of diabetes is still controversial. The correlation between glucose and insulin sensitivity is consistent with the idea that the degree of chronic hyperglycemia is a cause of excessive insulin resistance in type 2 diabetes, i.e. the insulin resistance which characterizes type 2 diabetes but not nondiabetic subjects matched for age, gender, family history and duration of diabetes. The study comprised a total of 76 subjects out of which 30 were normal, non-diabetic persons and the rest 46 were diabetics with different duration of time in years, after being diagnosed diabetic. Data was analyzed after dividing the subjects into four groups—Group 1 comprised of one year old diabetics, Group 2 was made up of those, who had diabetes, for the past 2–5 years, Group 3 included patients who were diabetic since more than 5 years and Group 4 included non-diabetics as the normal control group. The results obtained indicated that the HbA1c levels showed a significant increase with the duration of diabetes as well as the insulin level showed a significant correlation after adjustment for age, sex and duration of diabetes.     

Hypomagnesaemia in type-2 diabetes mellitus patients: A study on the status of oxidative and nitrosative stress

This study was undertaken to evaluate the levels of plasma magnesium, lipid peroxides, nitric oxide end products, erythrocyte membrane lipid peroxides, erythrocyte reduced glutathione and erythrocyte superoxide dismutase activity in type-2 diabetes mellitus patients. 60 patients with type-2 diabetes mellitus and 30 healthy control subjects were included in this study. Among 60 type-2 diabetic patients, 30 patients were without complication and 30 patients were with various complications. Decreased levels of plasma magnesium, erythrocyte reduced glutathione and erythrocyte superoxide dismutase activity while increased levels of plasma lipid peroxides, nitric oxide end products and erythrocyte membrane lipid peroxides were observed in patients with type-2 diabetes mellitus. We propose that, under the shadow of hypomagnesaemia, there is excessive production of reactive oxygen species and reactive nitrogen species as reflected by elevated lipid peroxides and nitric oxide end products concomitant with dwindled antioxidants and suggest their association with late complications in type-2 diabetes mellitus.     

Effect of immobilisation stress on lipid peroxidation and lipid profile in rabbits

Stress is one of the basic factors in the aetiology of a number of diseases such as atherosclerosis, coronary heart disease, aging, liver disease etc. Hence this work was designed to study the effect of stress in the form of forced immobilisation stress on lipid peroxidation and lipid profile in rabbits. The study was conducted in 25 healthy rabbits of either sex. Rabbits were subjected to forced immobilisation for two hours everyday for consecutive seven days. Blood samples were collected on day 1, 3 and 7 after immobilisation period. Malondialdehyde (MDA), a marker of lipid peroxidation was estimated by TBA assay method. Lipid profile was analysed by multichannel autoanalyser. There was statistically significant increase in MDA, total cholesterol, LDL, VLDL and triglycerides with immobilisation. These findings indicate that stress in the form of forced immobilisation increases lipid peroxidation and alter lipid profile, which may be responsible for pathophysiology of various diseases.     

Association of Single Nucleotide Polymorphisms of Adiponectin Gene with Type 2 Diabetes Mellitus,and Their Influence on Cardiovascular Risk Markers

Type 2 diabetes mellitus is a genetically heterogeneous condition, characterized by insulin deficiency and/or insulin resistance. The etiology of type 2 diabetes is complex, with involvement of genetic and environmental factors. The adipose tissue protein ‘adiponectin’ is known to increase insulin sensitivity with decreased risk of type 2 diabetes mellitus. The gene for adiponectin is present on chromosome 3q27, the association of number of single nucleotide polymorphisms of adiponectin gene with type 2 diabetes and its complications have been reported. In the present study the two most common SNPs +45T/G & +276G/T, and their association with type 2 diabetes mellitus and cardiovascular markers were studied. The significant difference in genotype frequencies of +45T/G & +276G/T was found in type 2 diabetic patients and controls, with odds ratio of 1.13 & 1.26 respectively. BMI, Fasting blood glucose, fasting insulin, HOMA IR, triglyceride and VLDL cholesterol levels were increased, and HDL cholesterol level was decreased in patients carrier for +45T/G SNP than the wild type. While only decrease in the HDL cholesterol was reported in carriers for SNP +276G/T than the wild type. The logistic regression analysis revealed the positive association of SNP +45T/G with total cholesterol & LDL cholesterol. And negative association of HDL cholesterol was found with SNPs +45T/G and +276G/T. The haplotype analysis shows the alterations in means of biochemical markers in the patients having haplotype (GG) for mutant allele of SNP +45T/G and wild allele for SNP +276G/T.     

Role of yoga in control of hyperglycemia in middle aged patients of non-insulin dependent diabetes mellitus

The effect of 40 days yoga training in 30 hospitalized non-insulin dependent diabetes mellitus (NIDDM) patients has been investigated after stopping the medication. Blood glucose response to oral glucose load measured as area index total (AIT), glycated haemoglobin (GHb) plasma lipids and lipoproteins measurements before and after yoga training have been compared. Yoga training resulted in a significant improvement in AIT, GHb and plasma triglycerides and cholesterol levels. The data suggest that yoga training along with diet and medical management provides an important metabolic control in NIDDM and may have a role in primary prevention of diabetes mellitus.     

Antidiabetic effect of Momordica charantia saponins in rats induced by high-fat diet combined with STZ

BackgroundThe harmful effects of type 2 diabetes mellitus and its complications have become a major global public health problem. In this study, the effects of Momordica charantia saponins (MCS) on lipid metabolism, oxidative stress, and insulin signaling pathway in type 2 diabetic rats were investigated.ResultsMCS could attenuate the tendency of weight loss of the model rats. It could also improve glucose tolerance; reduce fasting blood glucose, nonesterified fatty acid, triglyceride, and total cholesterol; and increase the insulin content and insulin sensitivity index of the rats. The activity of superoxide dismutase and catalase increased, and the content of malondialdehyde decreased in the liver and pancreas tissues of rats in MCS-treated groups significantly. In addition, the expression of p-IRS-1 (Y612) and p-Akt (S473) increased, and the expression of p-IRS-1 (S307) decreased in the liver tissues and pancreas tissues of rats in MCS-treated groups significantly.ConclusionMCS has an antidiabetic effect, which may be related to its improving the lipid metabolism disorder, reducing oxidative stress level, and regulating the insulin signaling pathway.How to cite: Jiang S, Xu L, Xu X, et al. Anti-diabetic effect of Momordica charantia saponins in rats induced by high-fat diet combined with STZ. Electron J Biotechnol 2020;43. https://doi.org/10.1016/j.ejbt.2019.12.001.     

Hypoglycemic, hypolipidemic and antioxidant properties of combination ofCurcumin fromCurcuma longa, Linn, and partially purified product fromAbroma augusta, Linn. in streptozotocin induced diabetes

Dietary spice components ofCurcuma longa andAbroma augusta have been screened for their protective effect against reactive oxygen species induced lipid peroxidation. They have been found to be efficient antioxidant when administered in combination. The purpose of the study was to investigate the effect of oral administration (300mg/Kg) of the aqueous extract of turmeric whose active ingredient isCurcumin andAbromine powder as a hypoglycemic agent mixed with diet. The effect of this aqueous extract on blood glucose, lipid peroxidation (LPO) and the antioxidant defense system in rat tissues like liver, lung, kidney and brain was studied for 8 weeks in streptozotocin induced diabetic rats. The administration of an aqueous extract of turmeric and abromine powder resulted in a significant reduction in blood glucose and an increase in total haemoglobin. The aqueous extract also resulted in decreased free radical formation in the tissues studied. The decrease in thiobarbituric acid reactive substances (TBARS) and increase in reduced glutathione (GSH), superoxide dismutase (SOD) and catalase (CAT) clearly showed the antioxidant property of the mixture. It is suggested that these changes initially counteract the oxidative stress in diabetes however, a gradual decrease in the antioxidative process may be one of the factors which results in chronic diabetes. These results indicate that the mixture of the two plants have shown antidiabetic activity and also reduced oxidative stress in diabetes. A combination ofAbroma augusta and Curcuma longa also restored the other general parameters in diabetic animals. The results were statistically analyzed and indicated that combination of herbal extracts showed better efficacy as compared to individual herbal plant extracts used.     

Antidiabetic and ameliorative potential of Ficus bengalensis bark extract in streptozotocin induced diabetic rats

The aim of the present study was to evaluate the antidiabetic and ameliorative potential of aqueous extract of Ficus bengalensis bark in streptozotocin induced diabetic rats. The effect of oral administration of aqueous extract of F. bengalensis bark on blood glucose, serum electrolytes, serum glycolytic enzymes, liver microsomal protein, hepatic cytochrome P-450 dependent monooxygenase enzymes and lipid peroxidation in liver and kidney of streptozotocin -induced diabetic rats was studied. Oral administration of Ficus bengalensis to fed, fasted and glucose loaded diabetic rats significantly [F > 0.05 (ANOVA) and P< 0.05 (DMRT)] decreased the blood glucose level at 5 hrs and restored the levels of serum electrolytes, glycolytic enzymes and hepatic cytochrome P-450 dependent enzyme systems and decreased the formation of liver and kidney lipid peroxides at the end of 12 weeks. Further, the aqueous extract of Ficus bengalensis at a dose of 500mg/kg/day exhibits significant antidiabetic and ameliorative activity as evidenced by histological studies in normal and Ficus bengalensis treated streptozotocin induced diabetic rats. On the basis of our findings, it could be used as an antidiabetic and ameliorative agent for better management of diabetes mellitus.     

Age related changes in lipid peroxidation and antioxidants in elderly people

Advanced age is associated with an accumulation of free radical damage, which leads to physiological and clinical modifications. Age related changes resulting from free radical reactions include increasing levels of lipid peroxides, alterations in enzyme activities and greater osmotic fragility. The present study was conducted to estimate the level of lipid peroxidation product-Malondialdehyde and antioxidants Catalase and Glutathione in elderly people. An increase in lipid peroxidation and decrease in antioxidants was observed in normal elderly people. Highly significant increase in MDA and decrease in antioxidants was observed in elderly people when complicated with diabetes and hypertension. Supplementation of antioxidants may prevent further oxidative injury in elderly people.     

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 hypoglycemic and antioxidant effect of<Emphasis Type="Italic">Ocimum sanctum</Emphasis>

Ocimum sanctum leaves have been traditionally used in treatment of diabetes mellitus. Dietary supplementation of fresh tulsi leaves in a dose of 2 gm/kg BW for 30 days led to significant lowering of blood glucose levels in test group. Intake ofOcimum sanctum also led to significant increase in levels of superoxide dismutase, reduced glutathione and total thiols, but marked reduction in peroxiodised lipid levels as compared to untreated control group. The leaves were found to possess both superoxide and hydroxyl free radical scavenging action. The present observations establish the efficacy ofOcimum sanctum leaves in lowering blood glucose levels and antioxidant property appears to be predominantly responsible for hypoglycemic effect.     

Free radical generation and lipid peroxidation among the dry cell industry workers exposed to carbon

A total of 75 healthy male dry cell industry workers exposed to carbon for 5, 8 and 10 years were compared with 48 controls matched for age and economic status with respect to free radical generation, lipid peroxidation and antioxidant levels. Lymphocytes were seperated from the whole blood and used for estimation of free radicals and antioxidants. Plasma lipid peroxidation products were estimated in the form of thiobarbituric acid reactive substances. Significant increase in free radical generation and lipid peroxidation products were observed in carbon exposed population than controls, and the increase was found to be significant with increase in the period of exposure. The levels of antioxidants i.e., superoxide dismutase (SOD) and catalase were found to decrease with the increase in exposure to carbon in industrial workers. These results suggest that exposure to carbon augments free radical generation, lipid peroxidation and promotes decline in antioxidant enzymes.