Abstract

Background: Paraoxonase is high-density lipoprotein (HDL)-associated esterase/lactonase implicated to play a role in the antioxidant and anti-inflammatory properties exerted by HDL. Increasing evidence support a role of free radicals and oxidative stress in neuronal damage induced by ischemia-reperfusion. The aim of this study was to further investigate the relationship between lipoprotein oxidative damage and stroke.

Methods: We compared the paraoxonase activity and levels of lipid hydroperoxides in plasma isolated from healthy subjects (n=50) and from stroke patients (n=49). Moreover, the correlations between biochemical markers and the National Institute of Health Stroke Scale (NIHSS), which is widely used to study neurological severity, were evaluated.

Results: Our results demonstrated, for the first time, that the activity of paraoxonase in plasma of stroke subjects was significantly lower than controls (p<0.001) and the levels of lipid hydroperoxides were significantly higher in plasma from patients (p<0.001). Moreover, using linear regression analysis, significant correlations between the activity of paraoxonase, lipid peroxidation and the severity of neurological deficit at admission were observed.

Conclusions: These results provide further evidence that oxidative stress and impairment of the antioxidant system may play a role in stroke. Antioxidant activity of plasma may be an important factor providing protection from neurological damage caused by stroke-associated oxidative stress.

Clin Chem Lab Med 2008;46:113–7.