Association of leptin receptor gene Q223R polymorphism on lipid profiles in comparison study between obese and non-obese subjects.

Objectives: Leptin is a hormone secreted from adipocytes. It regulates metabolism and energy homeostasis through the leptin receptor (LEPR) which is localized centrally in hypothalamus as well as in peripheral tissues. The aim of this study was to investigate the association of leptin receptor gene Q223R polymorphism on obesity in association with body mass index (BMI), lipid parameters, plasma leptin levels and homeostasis model assessment of insulin resistance (HOMA-IR).

Artichoke leaf extract reduces oxidative stress and lipoprotein dyshomeostasis in rats fed on high cholesterol diet.

Hypercholesterolemia and lipid peroxidation play complementary role in atherosclerosis. Artichoke leaf extract (ALE) is rich in natural antioxidants and has a cholesterol-reducing effect. However, there is no study investigating the effect of ALE on lipid levels and lipid peroxidation in experimental hypercholesterolemic conditions.

Effect of artichoke leaf extract on hepatic and cardiac oxidative stress in rats fed on high cholesterol diet.

Hypercholesterolemia and lipid peroxidation play complementary roles in atherosclerosis. Artichoke (Cynara scolymus L., Asteraceae) leaf extract (ALE), rich in antioxidants, has cholesterol-reducing effect.

Effect of taurine treatment on pro-oxidant-antioxidant balance in livers and brains of old rats.

The effect of taurine treatment on antioxidant defense in liver and brain tissues of old rats was investigated. Endogenous malondialdehyde (MDA) and diene conjugate (DC), ascorbic acid (AA)- and NADPH-induced lipid peroxide levels as well as non-enzymatic (glutathione--GSH, vitamin E and vitamin C) and enzymatic antioxidants (superoxide dismutase, glutathione peroxidase and glutathione transferase) were determined in livers and brains of young (5 months), old (22 months), and taurine-treated old rats. Taurine (2%, w/v; in drinking water) was administered to old rats for 6 weeks.

Age-related changes in plasma lipid peroxidation and antioxidant system in humans and rats.

This study was carried out on young (20-35 years) and old (60-85 years) men and rats (6 vs 22 months) to investigate the effect of aging on plasma lipid peroxidation and the antioxidant system. Plasma polyunsaturated fatty acid (PUFA), total fatty acid (TFA) and malondialdehyde (MDA) levels increased in aged humans and rats compared with young groups. However, plasma MDA/TFA ratios did not increase in aged humans and rats.

Effect of pretreatment with artichoke extract on carbon tetrachloride-induced liver injury and oxidative stress.

Artichoke is a plant with antioxidant properties. In this study, we investigated the effect of artichoke extract pretreatment on carbon tetrachloride (CCl4)-induced oxidative stress and hepatotoxicity. Rats were given artichoke leaf extract (1.

Lipid peroxidation potential and antioxidants in the heart tissue of beta-alanine- or taurine-treated old rats.

The aim of this study was to investigate the effect of the changes of taurine levels in the hearts of old rats on endogenous malondialdehyde (MDA) and diene conjugate (DC) levels and ascorbic acid (AA)- and NADPH-induced lipid peroxidation as well as non-enzymatic (glutathione, vitamin E and vitamin C) and enzymatic antioxidants (superoxide dismutase, glutathione peroxidase and glutathione transferase). Two groups of old (22 mo) rats were treated with beta-alanine (3%, w/v; in drinking water), a taurine depleting agent, or taurine (2% w/v; in drinking water) for 6 wk. Significant decreases were observed in taurine contents of hearts in old rats as compared to young (5 mo) rats.

Role of carnosine in preventing thioacetamide-induced liver injury in the rat.

Carnosine (beta-alanyl-L-histidine) is a dipeptide with antioxidant properties. Free radicals are involved in the pathogenesis of acute liver injury induced by thioacetamide (TAA). In this study, we investigated the effect of carnosine treatment on TAA-induced oxidative stress and hepatotoxicity.

Increased lipid peroxidation in serum and low-density lipoproteins associated with aging in humans.

This study was carried out in 140 healthy subjects who were divided into three subgroups of age: young (21-40 years), mature (41-60 years), and elderly (61-85 years) to investigate lipid peroxides and the antioxidant system in serum and low-density lipoproteins (LDL). Serum levels of cholesterol and LDL-cholesterol increased with age. The elderly group was found to have higher polyunsaturated fatty acid (PUFA) levels, thiobarbituric acid reactive substances (TBARS), diene conjugates, and lower cholesterol-adjusted vitamin E levels and antioxidant activity (AOA) as compared to the young group.

Evidence for oxidative stress in the hepatic mitochondria of bile duct ligated rats.

Lipid peroxidation increased both in the liver homogenates and in the hepatic mitochondrial fraction of bile duct ligated (BDL)-rats. Although mitochondrial superoxide dismutase (SOD) activity did not change in the liver, glutathione (GSH) levels and glutathione peroxidase (GSH-Px) activity decreased in hepatic mitochondrial fraction of BDL-rats as compared to sham-operated rats. In addition, GSH-Px and glutathione transferase (GST) activities decreased but SOD activity remained unchanged in the post-mitochondrial fraction of the liver from BDL-rats.

Mitochondrial lipid peroxides and antioxidant enzymes in the liver following phorone-induced glutathione depletion.

The levels of lipid peroxidation product (malondialdehyde = MDA) and vitamin C and the activities of glutathione peroxidase (GSH-Px) and superoxide dismutase (SOD) were determined in the liver and its mitochondrial fraction, in the rats 2 and 18 hr after the injection of phorone, a glutathione (GSH) depleting agent. GSH levels decreased in liver homogenate and its mitochondrial fraction after 2 hr of phorone treatment, but these values returned to normal levels at 18 hr. In GSH depleted conditions, hepatic vitamin C levels increased, GSH-Px and SOD activities remained unchanged in mitochondrial and post-mitochondrial fractions.

Endogenous and copper-induced lipid peroxidation and antioxidant activity of serum in hypercholesterolemic subjects.

Endogenous malondialdehyde and diene conjugate levels were increased in hypercholesterolemic subjects with serum cholesterol levels above 240 mg/dl as compared to normocholesterolemic subjects (below 20 mg/dl). A decrease in vitamin E/cholesterol and vitamin C/cholesterol ratios was observed in serum of hypercholesterolemic individuals. However, the susceptibility of serum to copper-induced lipid peroxidation and antioxidant activity were found unchanged.

Peroxidation potential and antioxidant activity of serum in patients with diabetes mellitus and myocard infarction.

Endogen malondialdehyde (MDA), diene conjugate levels, the susceptibility to copper-induced lipid peroxidation and antioxidant activity of serum were determined in patients with atherosclerotic diseases such as diabetes mellitus and myocard infarction. Lipid peroxidation susceptibility and antioxidant activity did not change, however, an increase in endogen MDA and diene conjugate levels was observed in serum of these patients. These results indicate the presence of oxidative stress in diabetes mellitus and myocard infarction.