Lipid peroxidation of fish oils

Fish and fish oils are the richest sources of ω-3 fatty acids. However, they are susceptible to lipid peroxidation due to their high degree of unsaturation. In the present study, the level of thiobarbituric acid reactive material in various fish oils available in the market with and without added Vitamin E was determined. The peroxide levels in fish oil heated to food frying temperature of 180°C and the effect of addition of vitamin E has also been studied. The results indicate that the peroxide levels in almost all the products available in the market were abnormally high irrespective of their Vitamin E content. This might be due to the inefficient methods used for processing and storage of fish oils. Addition of vitamin E was found to have a significant effect in lowering the rate of peroxidation of fish oil during thermal stress, showing that association of antioxidants with ω-3 fatty acids lowers the rate of lipid peroxidation.     

Lipid peroxidation and the levels of antioxidant enzymes in coronary artery disease

Coronary Artery Disease is the major cause of mortality and morbidity worldwide. Traditional risk factors account for only half of the morbidity and mortality from coronary artery disease. There is substantial evidence that oxidative stress plays the major role in the atherosclerotic process. The present study was undertaken to evaluate the level of lipid peroxidation (by measuring malondialdehyde) and antioxidant enzymes (ceruloplasmin, glutathione, superoxide dismutase) in coronary artery disease. Serum malondialdehyde levels and serum ceruloplasmin levels were significantly raised in all the subgroups of study group as compared to control group (p<0.001). Whole blood glutathione levels and hemolysate superoxide dismutase activity was significantly decreased in all the subgroups of study group as compared to control group (p<0.001). Above results suggests that the patients of coronary artery disease show increased oxidative stress and decreased levels of antioxidant enzymes. So it is recommended that the management protocol for coronary artery disease patients should include antioxidant supplementation along with simultaneous lowering of lipid peroxidation.     

Lipid peroxidation and antioxidant vitamins in urolithasis

The present, study was conducted to determine the level of malondialdehyde (MDA) as an index of free radial induced lipid peroxidation and antioxidant vitamins-vitamins A, vitamin C and vitamin E in 75 confirmed cases of urolithiasis. Significantly high level of MDA (p<0.001) with significantly low levels of vitamin E (p<0.001) and vitamin A (p<0.001) with no significant decrease in vitamin C (p>0.05) were observed in the plasma of urolithiasis cases as compared to normal controls. In conclusion, it appears that a role of lipid peroxidation and oxidative function exists in the pathogenesis of urolithiasis. But, the exact mechanism how this occurs remains to be elucidated.     

Lipid peroxidation and antioxidant status in patients with rheumatoid arthritis

The changes in the erythrocyte lipid peroxidation products (MDA), levels of glutathione (GSH), ascorbic acid and plasma vitamin E (non enzymatic antioxidant parameters) and activities of antioxidant enzymes superoxide dismutase (SOD), glutathione peroxidase (GP_X), catalase in erythrocytes and plasma glutathione - S - transferase (GST) activity were estimated in patients with rheumatoid arthritis. This work was undertaken to assess oxidative stress and anti oxidant status in patients with rheumatoid arthritis. It was observed that there was a significant increase in erythrocyte MDA levels, activities of SOD, GP_X, plasma GST and a significant decrease in erythrocyte GSH, ascorbic acid, plasma vitamin E levels and catalse activity in patients with rheumatoid arthritis when compared to controls. The results of our study suggests higher oxygen free radical production, evidenced by increased MDA and decreased GSH, ascorbic acid, vitamin E and Catalase activity, support to the oxidative stress in rheumatoid arthritis. The increased activities of antioxidant enzymes may be a compensatory regulation in response to increased oxidative stress.     

Lipid peroxides,vitamin E levels and glutathione peroxidase activity in serum of respiratory disease patients

The concentration of serum lipid peroxides, tocopherol and glutathione peroxidase (GPx) activity was measured in 75 patients (43 males and 32 females) of different respiratory diseases aged 15–40 years. The results were compared with the values obtained from 100 healthy persons of comparabie age. The patients of respiratory diseases showed elevated levels of lipid peroxides with concomitant reduction of tocopherol and glutathione peroxidase activity. When these patients were categorised into different groups depending on the type of the disease like pulmonary tuberculosis (PT), chronic obstructive pulmonary disease (COPD), pulmonary tuberculosis and chronic obstructive pulmonary disease (PT and COPD) and suppurative lung disease (SLD). There was no significant difference between the groups. A significant inverse relation was found between lipid peroxides versus tocopherol and glutathione peroxidase activity in patients of respiratory diseases. The results suggest the involvement of lipid peroxidation process in pulmonary damage.     

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.     

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.     

Total antioxidant capacity and lipid peroxidation in liver transplantation

Liver transplantation is an accepted therapy for chronic liver disease patients. These patients generally have low levels of fat soluble vitamins, which have important antioxidant roles. Therefore, this study was undertaken to investigate whether such patients had evidence of antioxidant depletion and increased lipid peroxidation before transplant and whether the subsequent ischemia and reperfusion encountered during liver transplantation have any effect on antioxidant levels and lipid peroxidation. We assessed plasma total antioxidant capacity and serum lipid peroxide in 12 patients undergoing liver transplantation and equal numbers of healthy subjects. We found that before reperfusion, antioxidant levels were significantly decreased along with significantly elevated lipid peroxidation levels as compared with healthy controls (P<0.001). On reperfusion of the liver graft, further declined values of total antioxidant accompanied with highly elevated lipid peroxidation were seen than those of pre-reperfusion samples (P<0.001). This data shows that patients undergoing liver transplant have lowered antioxidant defenses and evidence of free radical damage, which compound the additional insult of reperfusion injury. Therefore antioxidant therapy in these patients before transplantation may ameliorate the effects of reperfusion.     

Lipid peroxidation and antioxidant status in blood of rheumatoid arthritis patients

The main objective of the study was to assess the oxidative stress in plasma and erythrocytes of rheumatoid arthritis patients by measuring the levels of thiobarbituric acid reactive substances (TBARS), non-enzymatic antioxidants (vitamin E, C and reduced glutathione) and enzymatic antioxidants [superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GSHPx)]. This study has been conducted on twenty-two adult female rheumatoid arthritis patients and an equal number of healthy subjects. Elevated lipid peroxidation and multidirectional changes in the antioxidant defence system were noticed in patients with rheumatoid arthritis. The enhanced lipid peroxidation accompanied by disturbance in antioxidant status indicates that rheumatoid arthritis patients are more prone to free radical mediated oxidative damage.     

Plasma antioxidant vitamins and lipid peroxidation products in pregnancy induced hypertension

It has been suggested that antioxidant systems are impaired in pregnancy induced hypertension and hence patients are exposed to oxidative stress. In order to investigate the relationship between lipid peroxidation and certain antioxidant parameters in blood of pregnancy induced hypertension (PIH) cases, 25 normotensive and 23 PIH samples were studied. In the present study, thiobarbituric acid reactive substances showed a tendency to increase, however the increase remained statistically insignificant. Plasma ascorbic acid level remained unaltered and Vitamin E showed a tendency to increase in the study group. The findings implicate oxidative stress in the disease and cite the biochemical rationale for clinical trials of antioxidants to prevent and treat pregnancy induced hypertension.     

In vitro inhibition of lipid peroxidation in fish by turmeric (Curcuma longa)

The beneficial effects of ∈-3 fatty acids on human health have been well documented. Fish and fish oils are the richest sources of ∈-3 fatty acids. However, due to their high degree of unsaturation, they are highly susceptible to lipid peroxidation. Regular consumption of peroxidised oils may represent a risk factor for the induction and development of atherosclerosis. In view of the above reports, it was considered necessary to study the effects of tumeric on fish lipid peroxidation during standard cooking practices and on time-dependent changes in the peroxidation of fish homogenate. The antioxidant effect of α-tocopherol was also studied to confirm the relevance of the study. The results suggest that turmeric may be considered as a safe, cheap and readily usable antioxidant for food preparations.     

Correlation between lipid peroxidation and non-enzymatic antioxidants in pregnancy induced hypertension

The present study was designed to evaluate the lipid peroxidation and non-enzymatic antioxidants in pregnancyinduced hypertension (PIH) compared with healthy normal pregnant and non-pregnant as controls. 75 cases were studied of which 25 were normal healthy controls (Group A), 25 healthy pregnant women (Group B) of third trimester and 25 were PIH (Group C) of the same trimester. In PIH, malondialdehyde a lipid peroxidation product was significantly increased as compared to normal pregnant and non-pregnant controls. The nonenzymatic antioxidants like reduced glutathione, Vitamin-E, Vitamin-C and Vitamin-A were significantly decreased in normal pregnants as compared to controls. A further significant decrease was noticed in PIH compared to normal pregnants. A significant negative correlation was detected between lipid peroxidation and non-enzymatic antioxidant levels. Our study clearly indicates a relationship between elevated lipid peroxidation, decreased non-enzymatic antioxidant in PIH. The measurement of non-enzymatic antioxidants in plasma may be useful predictor of the likely development of PIH.     

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 short term vitamin E supplementation on lipid peroxidation in acute myocardial infarction

In view of sufficient body of evidence to substantiate the role of free radical mediated oxidative injury in myocardial infarction (M.I.), the utility of exogenous supplementation with antioxidant substance, vitamin E was studied. Forty patients of acute myocardial infarction were divided into two equal groups, one who received vitamin E and the other who did not. Plasma MDA levels showed a reduction in patients of M.I. who received vitamin E as well as in those who did not, however, the decrease was significantly more in the vitamin E treated subgroup.     

A comparative study on oxidative stress and antioxidant status in ischemic stroke patients with and without diabetes

The study was conducted to find out the extent of lipid peroxidation and antioxidant status in ischemic stroke patients (ISPs) with and without diabetes. Malondialdehyde (MDA) was studied as a marker of lipid peroxidation. Glutathione (GSH), uric acid and ceruloplasmin were estimated to study the antioxidant potential of ISPs. Significantly higher levels of MDA were found in both the groups of ISPs and the increase in MDA was more in ISPs without diabetes. GSH levels were decreased significantly in both the groups of ISPs and maximum decline was found in ISPs with diabetes. Uric acid levels were significantly increased in both the groups of ISPs. Ceruloplasmin levels were increased significantly in ISPs without diabetes, whereas its levels were slightly decreased in ISPs with diabetes. A negative correlation was found between MDA and the antioxidants GSH, uric acid and ceruloplasmin in ISPs with diabetes. This study suggests that there is an association between ischemic stroke and increased oxidative stress and the antioxidant potential is impaired in both the groups of ISPs with and without diabetes.     

Lipid peroxidation in erythrocytes of patients with type 2 diabetes mellitus

Lipid peroxidation by measurement of Thiobarbituric Acid Reactive Substances (TBARS) and antioxidant status by determining the activities of the enzymes, Catalase (Cat), Glutathione Peroxidase (GPx) and Superoxide Dismutase (SOD) and the level of Reduced Glutathione (GSH) in the erythrocytes of patients with type 2 Diabetes Mellitus were investigated. It was observed that the level of TBARS in the erythrocytes was increased by 50% showing a significant generation of free radicals in the erythrocytes of these patients. The activities of both Cat and SOD were enhanced while that of GPx was not altered. The level of GSH was also not changed.     

Relationship of plasma homocysteine with lipid profile parameters in ischemic heart disease

The present study was undertaken to explore the relationship of plasma homocysteine with other biochemical parameters in ischemic heart disease. Plasma levels of total homocysteine was measured by HPLC—fluorescence detection with internal standard in 60 ischemic heart disease patients and were compared with 30 age matched normal healthy controls. The significant increase of plasma homocysteine was observed in both myocardial infarction and chronic stable ischemic heart disease patients when compared with the controls. The hyperhomocysteinemia appears be to due to increased body demand of vitamins such as folic acid, vitamin B₁₂, B₆, B₂ either alone or in combination to regulate normal homocysteine metabolism.     

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.     

Antioxidant Effect of Caffeic Acid on Oxytetracycline Induced Lipid Peroxidation in Albino Rats

Caffeic acid is a well-known phenolic compound widely present in plant kingdom. The aim of this study was to investigate the possible protective effect of caffeic acid (CA) against oxytetracycline (OXT) induced hepatotoxicity in male Albino Wistar rats. A total of 30 rats weighing 150–170 g were randomly divided into five groups of six rats in each group. Oral administration of OXT (200 mg/kg body weight/day) for 15 days produced hepatic damage as manifested by a significant increase in serum hepatic markers namely aspartate transaminase (AST), alanine transaminase (ALT), alkaline phosphatase (ALP), lactate dehydrogenase (LDH), bilirubin and increased plasma and hepatic lipid peroxidation indices (TBARS and hydroperoxide). The present finding shows that the levels of enzymatic antioxidants namely superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx) were significantly decreased in OXT intoxicated rats. Upon oral administration of caffeic acid (40 mg/kg body weight/day) there were decreased hepatic marker activities, bilirubin and lipid peroxidation and increased enzymatic antioxidants in OXT + Caffeic acid group compared to Normal + OXT group(P < 0.05). Our study suggests that caffeic acid has antioxidant property and hepatoprotective ability against OXT induced toxicity.     

Comparative study on lipid peroxidation and antioxidant vitamins E and C inFalciparum andVivax malaria

Reactive oxygen species are thought to be involved in the pathogenesis of Malaria. To assess the extent of oxidative stress, a study was conducted in patients withPlasmodium falciparum malaria andPlasmodium Vivax malaria. Plasma Thiobarbituric acid reactive substances (TBARS) were measured to assess the degree of lipid peroxidation. Antioxidant status was measured by estimating the levels of Vitamins E and C. Results were compared with age and sex matched control subjects. This study suggests that plasma TBARS levels were significantly increased in malaria patients. The patients withP. falciparum infection showed significantly increased levels of lipid peroxides when compared toP. vivax malaria. The antioxidant Vitamins E and C were decreased significantly in malaria patients in both the groups. Maximum decline in Vitamin C was observed inP. vivax malaria. Therefore it is been hypothesized that antioxidant Vitamins E and C could provide protection against the oxidative stress induced by malaria.