Oxidative damage to plasma proteins in patients with chronic alcohol dependence: the effect of smoking.
BACKGROUND
Accumulating evidence implicates oxidative stress in ethanol-induced toxicity. Ethanol has been reported to be involved in oxidative damage, mostly in vitro, or in post mortem tissues, while biochemical abnormalities in the blood or serum are scanty or lacking. The aim of the present study was to examine the oxidative status of plasma proteins as markers of oxidative stress in subjects with chronic alcohol dependence (CAD). Since smoking has also been associated with oxidative stress this factor was also considered.


METHODS
A total of 71 patients with CAD and 61 healthy volunteers of comparable age were included in the study. The protein carbonyl assay was carried out in plasma, as a reliable measure of general oxidative protein damage, in these two groups.


RESULTS
Increased plasma protein carbonyls (PCs) were found in patients with CAD as compared with the control group [mean values (nmollmg protein): 4.73+/-1.46 and 3.62+/-0.91 respectively, p<0.000001]. Within the control group, smokers had higher PCs than the non-smokers, however this difference was of marginal significance [mean values (nmol/mg protein): 3.93+/-1.32 and 3.47+/-0.63, respectively]. The CAD group had significantly increased PCs compared with both the smoker and the non-smoker subgroups of the controls (p<0.001 and p<0.0001, respectively). Duration of alcohol consumption, daily alcohol intake, smoke load, folic acid and vitamin B12 levels did not correlate significantly with PC levels.


CONCLUSIONS
The above results support the evidence for systemic oxidative stress in CAD, which must be attributed mainly to alcohol consumption, while smoking may act synergistically.
Kapaki
Elisabeth
E
Department of Neurology, Athens National University, "Eginition" Hospital, 74 Vas. Sophia's Ave., Athens, Greece. ekapaki@med.uoa.gr
Liappas
Ioannis
I
Lyras
Leonidas
L
Paraskevas
George P
GP
Mamali
Ioanna
I
Theotoka
Ioulia
I
Bourboulis
Nikolaos
N
Liosis
Ioannis
I
Petropoulou
Olga
O
Soldatos
Konstantinos
K
D000328:Adult; D000437:Alcoholism / Q000097:blood*; D015415:Biomarkers / Q000378:metabolism; D001798:Blood Proteins / Q000187:drug effects* / Q000378:metabolism; D004347:Drug Interactions; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D018384:Oxidative Stress; D012907:Smoking / Q000009:adverse effects*
D015415:Biomarkers; D001798:Blood Proteins