Intense lipid peroxidation in premature clinical coronary atherosclerosis is associated with metabolic abnormalities

Oxidative status and reduced glutathione levels in premature coronary artery disease and coronary artery disease

Identifying patients at risk of developing premature coronary artery disease (PCAD) which occurs at age below 45 years old and constitutes approximately 7-10% of coronary artery disease (CAD) worldwide remains a problem. Oxidative stress has been proposed as a crucial step in the early development of PCAD. This study was conducted to determine the oxidative status of PCAD in comparison to CAD patients. PCAD (<45 years old) and CAD (>60 years old) patients were recruited with age-matched controls (n = 30, each group). DNA damage score, plasma malondialdehyde (MDA) and protein carbonyl content were measured for oxidative damage markers. Antioxidants such as erythrocyte glutathione (GSH), oxidised glutathione (GSSG), and glutathione peroxidase activity (GPx), superoxide dismutase (SOD) and catalase (CAT) were also determined. DNA damage score and protein carbonyl content were significantly higher in both PCAD and CAD when compared to age-matched controls while MDA level was increased only in PCAD (p<.05). In contrast, GSH, GSH/GSSG ratio, α-tocotrienol isomer, and GPx activity were significantly decreased, but only in PCAD when compared to age-matched controls. The decrease in GSH was associated with PCAD (OR = 0.569 95%CI [0.375 - 0.864], p = .008) and cut-off values of 6.69 μM with areas under the ROC curves (AUROC) 95%CI: 0.88 [0.80-0.96] (sensitivity of 83.3%; specificity of 80%). However, there were no significant differences in SOD and CAT activities in all groups. A higher level of oxidative stress indicated by elevated MDA levels and low levels of GSH, α-tocotrienol and GPx activity in patients below 45 years old may play a role in the development of PCAD and has potential as biomarkers for PCAD.

Protective effect of soybeans as protein source in the diet against cadmium-aorta redox and morphological alteration

We investigated the effects of cadmium exposition on thoracic aorta redox status and morphology, and the putative protective effect of soybeans in the diet. Male Wistar rats were separated into 6 groups: 3 fed with a diet containing casein and 3 containing soybeans, as protein source. Within each protein group, one was given tap water (control) and the other two tap water containing 15 and 100 ppm of Cd(2+), respectively, for two months. In rats fed with casein diet, 15 ppm of Cd induced an increase of thiobarbituric acid-reactive substances (TBARS), and of the catalase (CAT) and glutathione peroxidase (GPx) activities, which were even higher with 100 ppm of Cd(2+), in aorta. Also, 100 ppm Cd(2+) exposure increased superoxide dismutase (CuZnSOD) activity; CAT, GPX, SOD, Nrf2 and metallothioneine II mRNA expressions and CAT, GPx and NOX-2 protein levels, compared with control. Aorta endothelial and cytoplasmic alterations were observed. However, with the soybeans diet, 15 and 100 ppm of Cd(2+) did not modify TBARS levels; CAT, GPX and Nrf2 mRNA expressions; CAT, GPx and NOX-2 protein; and the aorta morphology, compared with control. The soybean diet attenuates the redox changes and protects against morphological alterations induced, in a dose-dependent way, by Cd in aorta.

Role of advanced oxidation protein products and Thiol ratio in patients with acute coronary syndromes

OBJECTIVES

To identify systemically detectable vascular inflammation associated to redox system unbalance, advanced oxidation protein products (AOPP), formed by HClO reaction with proteins, Thiol levels, and their ratio (AOPP/Thiol ratio) were measured in patients with acute coronary syndromes (ACS).

DESIGN AND METHODS

We evaluated AOPP/Thiol ratio together with CRP and IL-1β in 18 acute myocardial infarction (AMI) and in 16 unstable angina (UA) patients at admission, and in 16 control subjects (CTR); the measurements were repeated at 1 and at 6 months.

RESULTS

At admission, AMI and UA patients displayed higher AOPP/Thiol ratio and CRP and IL-1β compared to CTR subjects. A correlation between AOPP/Thiols and IL-1β in AMI was found. At follow-up, in UA only, AOPP/Thiol ratio and IL-1β levels still remained high.

CONCLUSIONS

The AOPP/Thiol ratio seems to affect the inflammatory process in ACS, and may represent a reliable marker of oxidative unbalance in this setting of patients.

Effect of ambient particulate matter exposure on hemostasis

Epidemiological studies have linked levels of particulate matter (PM) in ambient air to cardiovascular mortality and hospitalizations for myocardial infarction (MI) and stroke. Thrombus formation plays a primary role in potentiating acute cardiovascular events, and this study was undertaken to determine whether pulmonary exposure to PM alters hemostasis. PM was collected from the Chapel Hill, NC airshed and was administered to mice by intratracheal instillation at a dose previously shown to exacerbate myocardial ischemia-reperfusion injury. Twenty-four hours after exposure, an increase occurred in the number of circulating platelets and plasma concentrations of fibrinogen and soluble P-selectin. The concentration of tissue factor pathway inhibitor (TFPI) in plasma was decreased, whereas the plasma concentration of plasminogen activator inhibitor (PAI-1) was increased. Consistent with these observations, bleeding time from a tail-tip transection was shortened. These results provide evidence that PM exposure alters hemostasis in otherwise healthy animals and may thereby promote clot formation and impede clot resolution in susceptible individuals. The results also establish definite hemostatic endpoints that can be used to further investigate the effects of dose and particle characteristics on the toxicity of ambient particles.