Oxidative modification of LDL plays an important role in early atherogenesis but the mechanisms, nonenzymatic and/or enzymatic, by which LDL is oxidized in vivo remain to be established. Several lines of evidence suggest that cellular 15-lipoxygenase (arachidonate 15-oxidoreductase, EC.1.13.11.13) (15-LO) may contribute to oxidative modification of LDL, including recent studies demonstrating th...

Unsaturated lipids are rapidly oxidized to toxic products such as lipid hydroperoxides, especially when transition metals such as iron or copper are present. In a Fenton-type reaction Fe2+ converts lipid hydroperoxides to the very short-lived lipid alkoxyl radicals. The reaction was started upon the addition of Fe2+ to an aqueous linoleic acid hydroperoxide (LOOH) emulsion and the spin trap in ...

Food plants provide important phytochemicals which help improve or maintain health through various biological activities, including antioxidant effects. Cigarette smoke-induced oxidative stress leads to the formation of lipid hydroperoxides (LOOHs) and their decomposition product malondialdehyde (MDA), both of which cause oxidative damage to DNA. Two hundred forty-five heavy cigarette smokers c...

Lipid peroxidation is a well known example of oxidative damage in cell membranes, lipoproteins, and other lipid-containing structures. Peroxidative modification of unsaturated phospholipids, glycolipids, and cholesterol can occur in reactions triggered by i) free radical species such as oxyl radicals, peroxyl radicals, and hydroxyl radicals derived from iron-mediated reduction of hydrogen perox...

Background The aim of the study was to investigate the effect of propranolol on systemic oxidative stress and endotoxemia in patients with liver cirrhosis and clinically significant portal hypertension evidenced by the presence of esophageal varices. Methods Fourteen patients with liver cirrhosis and esophageal varices, not previously been treated with non-selective beta-blockers (NSBB), were...

GSH peroxidase (Px) catalyzes the reduction of lipid hydroperoxides (LOOH), known metabolic products of platelets and vascular cells. Because interactions between these cells are modulated by nitric oxide (NO) and LOOH inactivate NO, we investigated the effect of GSH-Px on the inhibition of platelet function by the naturally occurring S-nitrosothiol, S-nitroso-glutathione (SNO-Glu). Concentrati...

The present study was conducted in patients with cervix and ovarian carcinoma to evaluate the status of oxidative stress biomarkers as protein carbonyl and lipid hydro peroxides. Biomarkers of oxidative stress were measured as protein carbonyl (PC) and total lipid hydro peroxides (LOOH). Newly diagnosed women with carcinoma (n=100; 30-65 years of age) and agematched clinically healthy women (n=...

Leprosy is caused by invasion of Mycobacterium leprae bacilli occurring intracellularly. The innate methods by which the human body meets the challenge of invading live microbes is to destroy the microbes through an activation system leading to biochemical production of oxygen and other free radicals by the phagocytic cells[1] . Reactive Oxygen species (ROS) released during bacterial phagocytos...

The general reactivity of membrane lipid hydroperoxides (LOOHs) with the selenoenzyme phospholipid hydroperoxide glutathione peroxidase (PHGPX) has been investigated. When human erythrocyte ghosts (lipid content: 60 wt % phospholipid; 25 wt % cholesterol) were treated with GSH/PHGPX subsequent to rose bengal-sensitized photoperoxidation, iodometrically measured LOOHs were totally reduced to alc...

Biomimetic models of free radical-induced transformation of polyunsaturated fatty acids, such as micelles and liposomes, have been used for the study of lipid peroxidation and lipid isomerization. Free radical reactivity of thiol compounds is the common link between the two processes, since lipid peroxidation is inhibited by thiols, due to their H-donation ability, whereas lipid isomerization i...