Serum Lipid Hydroperoxide Levels Research Articles

Serum Lipid Hydroperoxide Levels and Paraoxonase Activity in Patients With Lung, Breast, and Colorectal Cancer

The objectives of this article are to investigate the serum lipid hydroperoxide (LOOH) levels and paraoxonase-1 (PON1) and arylesterase (ARE) activity in patients with lung, breast, and colorectal cancer. Serum PON1 and ARE activities and LOOH levels were measured in 110 patients with cancer and same number of age- and sex-matched controls. Serum LOOH levels were found to be increased while serum PON1 and ARE activities were found to be decreased in patients compared to controls. PON1 activity was found to be lower in patients with breast cancer than in patients with lung and colorectal cancer. There were positive correlations between the serum PON1 and ARE activities in patients with colorectal cancer. We concluded that decreased PON1 and ARE activities and increased LOOH levels might have a connection to carcinogenesis. PON1 activity is decreased in all patients but it does not seem to be related to metastase status except for colorectal cancer.

The Association of Serum Prolidase Activity and Erectile Dysfunction

Prolidase is a cytosolic exopeptidase that cleaves iminodipeptides with carboxy-terminal proline or hydroxyproline and plays a major role in collagen turnover. Collagen is the essential content in atherosclerotic plaque, playing a key role in the stability/instability and progression of endothelial dysfunction in the pathogenesis of erectile dysfunction (ED). Consequently, in this study we sought to determine serum prolidase activity and markers of oxidative stress, such as lipid hydroperoxide and total free sulfhydryl, in vasculogenic ED. We evaluated 92 patients with vasculogenic ED and 50 control subjects by clinical and laboratory investigations. We measured serum prolidase activity and serum total free sulfhydryl levels spectrophotometrically. Serum lipid hydroperoxide levels were determined with ferrous ion oxidation-xylenol orange method. We assessed the association of serum prolidase activity with the presence and severity of vasculogenic ED and clinical characteristics, as well as laboratory parameters. We also assessed the association of serum prolidase activity with the variables according to the vascular status of patients with vasculogenic ED. The comparison included 92 vasculogenic ED patients grouped into 3 categories according to the vascular status of patients with ED-arterial insufficiency (n = 26), veno-occlusive dysfunction (n = 37), and mixed-type impotence (n = 29)-and 50 controls. Receiver-operator characteristics (ROCs) were analyzed to find a cutoff value with the best sensitivity and lowest false-positive rate. Serum prolidase activity (53.5 +/- 5.5 U/L vs 45.7 +/- 4.9 U/L, respectively; P < .001) and serum lipid hydroperoxide levels were significantly increased in patients with vasculogenic ED compared with controls, whereas serum total free sulfhydryl levels were significantly decreased in patients with vasculogenic ED compared with controls (P < .001). The lowest and highest mean serum prolidase activities were detected in control participants and in patients with arterial insufficiency, respectively (analysis of variance P < .001). The overall findings of this study support the predictive accuracy of the serum prolidase activity in our cohort, with a statistically significant ROC value of 0.78. Findings of this study have shown that serum prolidase activity is significantly associated with the presence and severity of vasculogenic ED, and elevated serum prolidase activity might be an independent predictor of ED.

Protective effects of a standardised red orange extract on air pollution-induced oxidative damage in traffic police officers

Several pathological conditions have all been associated with a higher release of atmospheric pollutants. There is growing evidence that oxidative stress may represent one of the agents involved in the initiation and/or progression of many of these pathologies. The aim of the present study was to evaluate the effects of short-term dietary supplementation with a standardised red orange extract (ROC) on a group of traffic police officers exposed to traffic exhaust pollution and cigarette smoking, by measuring some noninvasive biomarkers of oxidative stress. At the beginning of the study, all the groups showed similar serum lipid hydroperoxide levels, but traffic officers showed lower serum concentrations of thiol (SH) groups; furthermore, the frequency of spontaneous sister chromatide exchanges (SCEs) in peripheral lymphocytes was increased by smoking (but not by pollution exposure alone) at a higher degree in subjects exposed to traffic pollution. After 1 month of ROC administration, serum lipid hydroperoxide levels decreased only in all non-smoking subjects; furthermore, SH group levels measured in traffic officers appeared restored to normal values observed in the respective controls. Finally, the increase in SCE frequency induced by smoking was reduced by treatment with ROC especially in traffic officers. Our study suggests that ROC supplementation could be useful to minimise the detrimental effects caused by exposure to air pollution and smoking.

The association of serum prolidase activity with the presence and severity of coronary artery disease

Prolidase is a cytosolic exopeptidase that cleaves iminodipeptides with carboxy-terminal proline or hydroxyproline and plays major role in collagen turnover. Collagen is the essential content in atherosclerotic plaque playing a key role in the stability/instability of and progression of coronary artery disease (CAD). Consequently, in this study we sought to determine serum prolidase activity and markers of oxidative stress such as lipid hydroperoxide and total free sulfhydryl in CAD. We have evaluated 199 patients with CAD and 122 control cases with clinical, electrocardiographic, and laboratory investigation. We have measured serum prolidase activity and serum total free sulfhydryl levels spectrophotometrically. Serum lipid hydroperoxide levels were determined with ferrous ion oxidation-xylenol orange method. We assessed the association of serum prolidase activity with the presence and severity of CAD and clinical characteristics, and laboratory parameters. Serum prolidase activity (52.5+/-5.6 vs. 46.7+/-5.1 U/l, respectively, P<0.001) and serum lipid hydroperoxide levels were significantly increased in patients with CAD compared with control cases whereas, serum total free sulfhydryl levels were significantly decreased in patients with CAD compared with control cases. Serum prolidase activity and total free sulfhydryl levels were independent predictors of the presence of CAD [(chi=75.532, ss=0.212, P=0.003) and (chi=25.969, ss=-30.486, P=0.019), respectively] and Gensini score [(beta=0.276, P<0.001) and (beta=-0.274, P<0.001), respectively]. Independent predictors of serum prolidase activity were serum high-density lipoprotein cholesterol (beta=-0.138, P=0.023) and urea levels (beta=0.146, P=0.036), and Gensini score (beta=0.317, P<0.001). Findings of this study have shown that serum prolidase activity is significantly associated with the presence and severity of CAD, and elevated serum prolidase activity might be an independent predictor of coronary atherosclerosis.