Impact of Essentiale L on ethanol-induced changes in rat brain and erythrocytes.

INTRODUCTION: The present study was designed to investigate the effect of Essentiale L, a mixture of polyenylphospholipids from soybeans, on oxidative stress in various brain regions, on erythrocytes (RBC) and on RBC membrane composition in ethanol-administered rats. METHODS: Adult male albino rats of body weight 150-170 g were divided into four groups and administered either isocaloric glucose (5 g/kg body weight/day) or ethanol (6 g/kg body weight/day) through oral gavage. Essentiale L was administered to a set of ethanol-fed rats and the control rats at a dosage of 300 mg/kg body weight/day through oral gavage. The treatment protocol was carried out for 45 days. At the end of the experimental period, the animals were sacrificed, and the biochemical parameters related to the lipid profile, oxidative stress and thiol status were assayed in the brain regions, RBC and RBC membrane. RESULTS: Ethanol administration resulted in increased levels of lipid peroxidation products in RBC and different brain regions, such as the cortex, cerebellum, striatum, hippocampus and hypothalamus, and depletion of enzymatic and nonenzymatic antioxidants and alterations in oxidised glutathione/glutathione (GSSG/GSH) ratio and thiol groups (protein-bound and total), signifying oxidative stress. Ethanol-treated rats also showed significant alterations in protein content and lipid composition in RBC membranes. Significant differences in the relative proportions of hexose, hexosamine and sialic acid of the membranes were observed. Administration of Essentiale L prevented all the alterations induced by ethanol and returned their levels to near-normal. CONCLUSION: These findings suggest that Essentiale L, a therapeutic adjunct for liver diseases, also has bioprotective effects on nonhepatic tissues and cells.

(-) Epigallocatechin Gallate (EGCG) Prevents Lipid Changes and Collagen Abnormalities in Chronic Ethanol-Fed Rats.

ABSTRACT The objective of the study is to examine the influence of (-) epigallocatechin gallate (EGCG), a green tea component, on lipid and collagen abnormalities in chronic ethanol-fed rats. Solubility properties, aldehyde content, fluorescence, and peroxidation were analyzed in collagen samples isolated from liver. Chronic alcoholism (6 g/kg/day x 60 days) was associated with fatty liver and collagen accumulation. Significant alterations in the levels of lipids (cholesterol, phospholipids, free fatty acids, and triglycerides) and total collagen were observed in liver. Collagen obtained from ethanol-fed rats showed alterations in solubility properties, increased fluorescence, peroxidation, and aldehyde content. Coadministration of EGCG along with ethanol significantly reduced the levels of liver lipids and collagen, improved the solubility properties of collagen, and caused a reduction in cross-linking as evidenced by a decrease in fluorescence, peroxidation, and aldehyde content. Histology of liver sections of ethanol-fed rats showed accumulation of fat and collagen, which were largely prevented by EGCG administration. The possible mechanisms in the protective action of EGCG in alcoholic liver disease are suggested and discussed.

Effect of food seasoning spices mixture on biomarkers of oxidative stress in tissues of fructose-fed insulin-resistant rats.

High fructose feeding in normal rats induces insulin resistance and also facilitates oxidative damage. The present study examines the effects of a spices mixture (SM) on oxidative stress markers and antioxidant potential in tissues of high fructose-fed insulin-resistant rats. Male Wistar rats received a semisynthetic diet containing either 60% fructose or 60% starch. SM administration at three different doses (10, 30, and 50 mg/day per rat) was initiated orally 15 days later and continued for the next 30 days. After the total experimental period of 45 days, peroxidation of lipids and antioxidant status in liver and kidney were quantified. Fructose-treated rats showed increased levels of peroxidation indices such as thiobarbituric acid-reactive substances and lipid hydroperoxides in tissues. The condition was associated with an inadequate antioxidant system. Administration of SM along with fructose diet reduced the levels of peroxidation markers in tissues and improved the antioxidant status. The positive effect of SM on the oxidant-antioxidant balance could be attributed to the active constituents of the different spices present in the mixture.

Cinnamon bark extract improves glucose metabolism and lipid profile in the fructose-fed rat.

INTRODUCTION: The present study was designed to investigate whether cinnamon bark extract (CBEt) mitigates the adverse effects of fructose loading on glucose metabolism and lipid profile in rats. METHODS: Adult male albino rats of body weight 150-170 g were divided into five groups and fed with either control or high fructose diet (HFD). CBEt was administered to HFD-fed rats orally at two doses (a low and a high dose) while the control diet-fed rats were treated with a high dose of CBEt. The treatment protocol was carried out for 60 days after which the oral glucose tolerance test was carried out. Biochemical parameters related to glucose metabolism and lipid profile were assayed. RESULTS: The levels of glucose, insulin and protein-bound sugars were higher and activities of enzymes of glucose metabolism were altered in HFD-fed rats, as compared to control animals. The levels were brought back to near-normal when administered with CBEt at high dose. CBEt also prevented the hyperlipidaemia observed in fructose-fed rats and improved glucose tolerance. CBEt did not show any significant effect in fructose-fed rats when administered at low dose. CONCLUSION: These findings indicate the improvement of glucose metabolism in-vivo by CBEt in fructose-fed rats.

Food seasoning spices mixture improves glucose metabolism and lipid profile in fructose-fed hyperinsulinemic rats.

Fructose feeding has been shown to induce insulin resistance in rats, associated with hyperinsulinemia, hyperglycemia, and hypertriglyceridemia. We have investigated the effect of administering food seasoning spices mixture (SM) on glucose, insulin, and lipids in circulation and carbohydrate enzymes in the erythrocytes of high fructose-fed rats. Additionally, we also measured the protein glycation status by assaying the levels of glycated hemoglobin, fructosamine, and plasma protein glycation. Male Wistar rats received a daily diet containing either 60% fructose or 60% starch (control). The rats were administered SM at three different doses (10, 30, or 50 mg/day per rat) orally 15 days later. At the end of the 45-day experimental period, fructose-fed rats showed significantly higher levels of plasma glucose and insulin, dyslipidemia, and alterations in enzyme activities. Treatment with SM significantly reduced plasma glucose and insulin levels and brought about a favorable lipid profile. In these rats, the activities of enzymes of glucose metabolism were normal. These effects were observed at all three doses of SM. High homeostasis model assessment (HOMA) values indicated insulin resistance in fructose-fed rats, while the HOMA values in SM-treated fructose-fed rats were comparable to those of control rats. We conclude that administration of SM improves glucose metabolism and plasma lipid profile in fructose-fed rats, possibly through improved insulin-sensitizing actions of the active constituents.

Effect of taurine on biomarkers of oxidative stress in tissues of fructose-fed insulin-resistant rats.

INTRODUCTION: The present study was designed to investigate whether taurine mitigates fructose-induced oxidative stress in rat tissues such as heart and kidney. METHODS: Male Wistar rats of body weight 170-190 g were divided into four groups containing six rats each. Control animals received the control diet containing starch while fructose-fed animals received a fructose-enriched diet (greater than 60 percent of total calories). Fructose and taurine rats received the fructose diet and two percent taurine solution to drink. Control and taurine rats received the control diet and two percent taurine solution. After the treatment period of 30 days, insulin resistance index, by homeostasis model assessment (HOMA) was determined. The levels of lipid peroxidation markers, the enzymatic and non-enzymatic antioxidants status in heart and kidney tissues were measured. RESULTS: Fructose rats showed high values of HOMA, increased lipid peroxidation and impaired antioxidant status. Taurine treatment to fructose rats attenuated the increased lipid peroxidation, enhanced the levels of antioxidants and improved insulin sensitivity. CONCLUSION: Inhibition of peroxidation markers and upregulation of antioxidant activity in rat tissues by taurine signify the potential utility of taurine as an adjunct in treatment of insulin resistance.

Influence of 6-week exercise training on erythrocyte and liver antioxidant defense in hyperinsulinemic rats.

High dosage of fructose in rats causes insulin resistance and hyperinsulinemia. This study investigates the effect of physical exercise on oxidant-antioxidant balance in rats fed a high fructose diet, which show characteristic features of insulin resistance. Products of lipid peroxidation and the activity of enzymic antioxidants namely superoxide dismutase, catalase, glutathione peroxidase, glutathione-S-transferase and glutathione reductase, in red blood cells (RBCs) and liver were assayed. Levels of non-enzymic antioxidants alpha-tocopherol and ascorbic acid and of protein and non-protein thiols were also determined. The levels of lipid peroxides, diene conjugates, lipofuscin and hydroperoxides were significantly higher in the liver of fructose-fed rats. The RBCs showed significantly higher susceptibility to H(2)O(2)-induced stress compared to control rats. Inadequate antioxidant system was noted in high fructose-fed rats. Physical training to these rats reversed the adverse effects, which could be important in alleviating the pathological consequences of insulin resistance.

Metformin attenuates blood lipid peroxidation and potentiates antioxidant defense in high fructose-fed rats.

The implication of oxidative stress in the pathology of insulin resistance has been shown recently. We investigated the effect of an insulin sensitizer, metformin, on the plasma lipid peroxidation and antioxidant defense system in the erythrocytes of high fructose fed rats which form an animal model of insulin resistance. The experimental animals were divided into two batches of 12 animals each. The control batch received the control diet, containing starch; the fructose group was given the high fructose diet. At the end of second week these were subdivided into two groups; one was given metformin (50 mg/kg/day in water) by gastric intubation and other group was left untreated. The rats were continued on the same dietary regimen for the next two weeks. Fructose-fed rats showed hyperglycemia, hyperinsulinemia and hypertriglyceridemia at the end of four weeks. Enhanced plasma lipid peroxidation and inadequate cellular antioxidant defense system were observed in them. Administration of metformin was associated with significant normalization of circulating insulin, glucose and triglyceride concentrations. The abnormal triglyceride distribution in the lipoprotein fractions was also ameliorated by metformin therapy. The imbalance between peroxidation and antioxidant defense system was mitigated when fructose-fed rats were treated with metformin. In the control rats, metformin did not affect the parameters studied. Significant positive correlation was obtained between insulin, triglycerides and glucose concentrations with lipid hydroperoxides suggesting that these metabolic variables could influence the lipid peroxide levels in plasma.