Lipid peroxidation in type 2 normolipidemic diabetic patients

Selenium downregulates RAGE and NFκB expression in diabetic rats

Diabetes is one of the leading causes of death in developed and developing countries. Oxidative stress has been proposed to play a crucial role in the pathogenesis of diabetic vascular complications. In recent years, selenium has been shown to mediate a number of insulinlike actions in a dose-dependent fashion both in vitro and in vivo. In this study, the effect of selenium as sodium selenite was investigated in streptozotocin-induced diabetic rats at the dose of 1 μg sodium selenite/kg body weight. Selenium supplementation restored the streptozotocin-induced alterations in the activities of antioxidant enzymes, decreased the serum glucose level, glycated hemoglobin content as well as the levels of lipid peroxidation products, and downregulated the expressions of both NFkB and RAGE. The histopathological studies also reinforce our findings. Hence, selenium has a protective role in streptozotocin-induced diabetes mellitus.

Development of an on-line weak-cation exchange liquid chromatography-tandem mass spectrometric method for screening aldehyde products in biological matrices

This paper focuses on the development and optimization of an on-line weak-cation exchange SPE (WCXE) coupled to gradient HPLC with tandem MS detection. The system enables the selective purification and re-concentration of the in-vial derivatized aldehydes from plasma and urine samples. Aldehydes are important as biomarkers for oxidative stress. Using a derivatization cocktail consisting of 4-(2-(trimethylammonio)ethoxy)benzenaminium dibromide (4-APC) and NaBH3CN in the screening and detection of known and unknown aldehyde biomarkers, one can take advantage of the specific fragmentation characteristics of this derivatization reagent in MS/MS. The WCXE column gives the advantages of direct injection of the sample after protein precipitation and centrifugation into the WCXE-LC-MS/MS system. Injection volumes up to 50 microl can be injected without overloading the WCX column. Detection limits of 0.5 nM can be reached for the detection of the derivatized aldehydes. The system is robust with low intra-/inter-day variation in retention time and peak area. An in vitro model shows how derivatized aldehydes in human and rat plasma are detected. Finally, plasma treated with radical inducer shows elevated aldehyde species compared to untreated plasma.

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.

Decreased lipid peroxidation following periodontal therapy in type 2 diabetic patients

BACKGROUND

Although diabetes mellitus and periodontal disease promote atherosclerosis, the relation of oxidative stress with these diseases remains unclear. To investigate the influence of periodontal disease on oxidative stress, we assessed the effects of initial periodontal therapy on lipid peroxide (LPO), an oxidative stress index, in type 2 diabetic and non-diabetic patients.

METHODS

Seventeen subjects with or without type 2 diabetes were enrolled in this intervention study. No patient had a history of cardiovascular or peripheral vascular disease. Five type 2 diabetic and six non-diabetic patients, all with moderate to severe periodontal disease, received and completed the initial periodontal therapy and examination. Before and after the therapy, patients underwent medical examinations and blood determinations, including LPO.

RESULTS

Before the therapy, the periodontal probing depth and bleeding on probing (BOP) were similar between groups. LPO, triglyceride, and white blood cell counts were significantly higher in diabetic than non-diabetic patients. Therapy improved the periodontal parameters in both groups and significantly decreased LPO in diabetic patients. Anti-malondialdehyde-modified low-density lipoprotein (MDA-LDL) antibody, a marker of oxidized LDL, significantly decreased with treatment in both groups. Overall, Spearman rank correlation showed no significance between periodontal parameters and LPO or anti-MDA-LDL antibody, but BOP tended to correlate with LPO in diabetic patients (r = 0.585; P = 0.0791).

CONCLUSION

Although this is a small and preliminary study, and the changes of LPO and anti-MDA-LDL antibody were within the normal range, the initial periodontal therapy significantly decreased LPO, an oxidative stress index, in type 2 diabetic patients with periodontal disease.

Study of lipid peroxide and lipid profile in diabetes mellitus

The study was designed to find out the correlation between lipid peroxidation, lipoprotein levels to severity and complication of diabetes mellitus. Degree of lipid peroxidation was measured in terms of malondialdehyde (MDA) along with lipid profile and blood glucose in diabetes mellitus. It is categorised into insulin dependent diabetes mellitus (IDDM), non insulin dependent diabetes mellitus (NIDDM) and diabetes mellitus(DM) with complication.Total 112 known diabetic patients and 52 non-diabetic controls were studied. These patients were grouped as per the concentration of fasting blood glucose level i.e. controlled, poorly controlled, and uncontrolled group. There are significant increase in the lipid peroxide (MDA) and lipid profile except HDL cholesterol which is decreased, has been found in all groups as compared to controls In NIDDM group lipid peroxidation was markedly increased than IDDM group and it was higher in DM with complications. Other finding observed was that the level of lipid peroxide increased as per the increase in concentration of blood glucose. The increase lipid peroxidation in the hyperglycemic condition may be explained, as the superoxide dismutase enzyme which is antioxidant becomes inactive due the formation of superoxide radical within the cell. Maximum lipid peroxidation leads to the damage of the tissue and organs which results into complication in diabetic patients. High levels of total cholesterol appear due to increased cholesterol synthesis. The triglyceride levels changes according to the glycemic, control. The increase may be due to overproduction of VLDL-TG.It is concluded that good metabolic control of hyperglycemia will prevent in alteration in peroxidation and the lipid metabolism, which may help in good prognosis and preventing manifestation of vascular and secondary complication in diabetes mellitus.

Lipid Peroxidation Early after Brain Injury

The role of lipid peroxidation after brain injury is still not completely understood, and results of different studies have been equivocal. In this study, three proposed peroxidation markers were determined in patients early after isolated head injury and results compared to healthy controls. Malondialdehyde (MDA) and thiobarbituric acid-reactive substances (TBARS) were measured in plasma, and n-pentane was determined in patients' exhaled air. For MDA and TBARS no significant differences could be shown (0.267 vs. 0.358 ng/mL, and 0.896 vs. 0.814 ng/mL in patients vs. healthy volunteers, respectively). n-Pentane, however, was significantly increased in the expired air of patients (0.471 vs. 0.118 nmol/L in healthy volunteers). Similar results for n-pentane were obtained when only male patients and volunteers were considered (0.510 vs. 0.113 nmol/L). Stratification according to clinical outcome showed significantly higher values for n-pentane in male patients with poor outcome (0.656 nmol/L) in comparison with healthy male volunteers (0.113 nmol/L). No difference was found when patients were stratified according to the presence or absence of subarachnoid hemorrhage. It is concluded that, only in a sub-population of patients with brain injury, lipid-peroxidation is a crucial mechanism. n-Pentane seems to be a valuable marker to detect lipid peroxidation early after brain trauma. Malondialdehyde may be of value only later in the course of the disease. TBARS are not a specific marker and should therefore not be used.

Breath markers and soluble lipid peroxidation markers in critically ill patients

Free radical-mediated inflammatory processes account for a great portion of morbidity and mortality in critically ill patients. The purpose of this study was to determine two plasma peroxidation markers and three volatile markers related to lipid peroxidation, metabolic activity and cholesterol metabolism, and to explore relationships between the different markers and patients' clinical status. Substances were analyzed in whole blood and in exhaled air in patients with head injury, acute respiratory distress syndrome (ARDS) and in those being at risk of developing ARDS. These results were compared with the baseline measurements in healthy individuals. Additionally, patients were assessed according to their inflammatory status. Concentrations of malondialdehyde and thiobarbituric acid-reactive substances in plasma as well as pentane concentrations in breath increased with increasing inflammatory status. Although these compounds are generated through peroxidation of fatty acids, concentrations of these markers were significantly different in patient groups. Isoprene concentrations were lowest in the ARDS group. Acetone concentrations were not different between patient groups. We conclude that for the assessment of lipid peroxidation and other inflammatory reactions a set of parameters has to be defined. More detailed insights into inflammatory processes can be obtained when the volatile markers and the serum markers are considered together.

Effect of Nigella sativa on glucose concentration, lipid peroxidation, anti-oxidant defence system and liver damage in experimentally-induced diabetic rabbits

This study was carried out to investigate whether Nigella sativa could decrease the lipid peroxidation, increase the anti-oxidant defence system and also prevent the lipid-peroxidation-induced liver damage in experimentally induced diabetic rabbits. Fifteen New Zealand male rabbits were divided into three experimental groups: control, diabetic and diabetic and N. sativa-treated. The diabetes mellitus (DMI) was induced in the rabbits using 150 mg/kg of 10% alloxan. The diabetic + N. sativa-treated group was given extract of N. sativa seeds orally every day for 2 months after induction of DM. At the end of the 2-month experiment, blood samples were collected to measure malondialdehyde (MDA), glutathione (GSH), ceruloplasmin and glucose concentration, and livers were harvested for histopathological analysis. Treatment with N. sativa decreased the elevated glucose and MDA concentrations, increased the lowered GSH and ceruloplasmin concentrations, and prevented lipid-peroxidation-induced liver damage in diabetic rabbits. It was concluded that N. sativa might be used in diabetic patients to prevent lipid peroxidation, increase anti-oxidant defence system activity and also prevent liver damage.

Cardiovascular disease in diabetes mellitus type 2: a potential role for novel cardiovascular risk factors

A major consequence of diabetes mellitus type 2 is the accelerated development of atherosclerosis. Assessment of conventional risk factors such as plasma lipids, lipoproteins and hypertension only partly account for the excessive risk of developing cardiovascular disease in this population. Increasing evidence has emerged suggesting that conditions associated with diabetes mellitus type 2, such as insulin resistance, hyperinsulinemia and hyperglycemia, may also play a significant role in regulating 'novel' cardiovascular risk factors. These factors and their potential roles in the development of atherosclerosis and cardiovascular events are discussed in this review.

Effects of gliclazide versus metformin on the clinical profile and lipid peroxidation markers in type 2 diabetes

The sulfonylurea gliclazide and the biguanide metformin have different mechanisms to reduce glycemia. We performed a randomized study to compare these two agents with respect to glycemic control and effects on lipid peroxidation markers in 36 adult patients with type 2 diabetes. Both agents significantly decreased glycosylated hemoglobin ([HbA1c] P < .05), fructosamine (P < .05), and the glucose-excursion curve during the oral glucose tolerance test ([OGTT] P < .01). With regard to the insulin curve during this test, no significant change was observed with metformin and a significant increase was measured with gliclazide (P < .05). Considering the small number of events, no significant difference was detected in the number of hypoglycemic episodes between the two agents. More upper-gastrointestinal (GI) symptoms were observed with metformin compared with gliclazide (P < .05). Even with no change in the standard lipid profile, both agents increased serum vitamin E (P < .01 for gliclazide and P < .05 for metformin) and decreased the level of lipid peroxidation markers in low-density lipoprotein (LDL) and high-density lipoprotein (HDL) particles (P < .05). Despite different mechanisms of action, gliclazide and metformin demonstrated comparable levels of efficacy and complementary effects on lipid peroxidation markers.