Abstract-The objective was to study oxidative status, antioxidant activities, and reactive oxygen species byproducts in whole blood and mononuclear peripherals cells and their relationship with blood pressure. Sixty-six hypertensive patients and 16 normotensive volunteers as a control group were studied. In both, whole blood and peripheral mononuclear cells oxidized/reduced glutathione ratio and malondialdehyde was significantly higher, and the activity of superoxide dismutase, catalase, and glutathione peroxidase was significantly lower in hypertensive patients when compared with normal subjects. The content of damaged base 8-oxo-2Ј-deoxyguanosine in nuclear and mitochondrial deoxyribonucleoproteins of hypertensive subjects was also significantly higher than that of the normotensive control subjects. No differences in these measurements were found among hypertensive subjects grouped in tertiles of 24-hour average mean blood pressure or between "white-coat" and established hypertensive subjects. Furthermore, no relationship was observed between the average of 24-hour mean blood pressure and oxidized/reduced glutathione ratio, reactive oxygen species byproducts, malondialdehide, or genomic 8-oxo-2Ј-deoxyguanosine. In whole blood and in mononuclear cells from hypertensive subjects, there was an increase in oxidative stress and a reduction in the activity of antioxidant mechanisms that appeared to be independent of the blood pressure values. Key Words: oxidative stress Ⅲ hypertension, renovascular Ⅲ hypertension, obesity Ⅲ risk factors Ⅲ antioxidants Ⅲ DNA O xidative stress, an excessive production of reactive oxygen species (ROS) outstripping antioxidant defense mechanisms, has been implicated in pathophysiological conditions that affect the cardiovascular system such cigarette smoking, hypercholesterolemia, diabetes, and hypertension. 1-3 Oxidative stress accompanying hypertension in animal models includes spontaneous hypertension, 4 renovascular hypertension, 5 deoxycorticosterone acetate-salt model, 6 and obesity-related hypertension. 7 Moreover, reducing superoxide radicals by infusion of superoxide dismutase (SOD) significantly decreases blood pressure in spontaneously hypertensive rats. 8 In humans, hypertension is also considered a state of oxidative stress that can contribute to the development of atherosclerosis 9 and other hypertension-induced organ damage. 10 Assessment of antioxidant activities and lipid peroxidation byproducts in hypertensive subjects indicates an excessive amount of ROS and a reduction of antioxidant mechanism activity in both blood as well as in several other cellular systems, 11 including not only vascular wall cells 12 but also those found in circulating blood. 13 Another consequence of the overproduction of ROS is the instability of critical nonlipidic macromolecules, which may have important consequences on cellular functions. Among these, genomic and mitochondrial DNA 14 are especially relevant. Up to now, however, no information concerning the damage of both types of DNA in ce...

The aim of the present study was to evaluate whether olive oils high in phenolic compounds influence the oxidative/antioxidative status in humans. Healthy men (n = 12) participated in a double-blind, randomized, crossover study in which 3 olive oils with low (LPC), moderate (MPC), and high (HPC) phenolic content were given as raw doses (25 mL/d) for 4 consecutive days preceded by 10-d washout periods. Volunteers followed a strict very low-antioxidant diet the 3 d before and during the intervention periods. Short-term consumption of olive oils decreased plasma oxidized LDL (oxLDL), 8-oxo-dG in mitochondrial DNA and urine, malondialdehyde in urine (P < 0.05 for linear trend), and increased HDL cholesterol and glutathione peroxidase activity (P < 0.05 for linear trend), in a dose-dependent manner with the phenolic content of the olive oil administered. At d 4, oxLDL after MPC and HPC, and 8-oxo-dG after HPC administration (25 mL, respectively), were reduced when the men were in the postprandial state (P < 0.05). Phenolic compounds in plasma increased dose dependently during this stage with the phenolic content of the olive oils at 1, 2, 4, and 6 h, respectively (P < 0.01). Their concentrations increased in plasma and urine samples in a dose-dependent manner after short-term consumption of the olive oils (P < 0.01). In conclusion, the olive oil phenolic content modulated the oxidative/antioxidative status of healthy men who consumed a very low-antioxidant diet.

No abstract

No abstract