Measurement of arylesterase and paraoxonase enzyme activity in haemorrhagic and ischemic stroke

Background: Stroke is a multifactorial disease arising from genetic and environmental risk factors or their interaction. The underlying cause of the majority of ischemic strokes is an atherosclerotic plaque in the carotid arteries. Oxidative modification of serum low density lipoproteins (LDL) in the arterial wall is considered to be an important early step in the development of atherosclerosis. Paraoxonase-1 (PON1) has been considered as an anti-atherosclerosis factor, because it can reduce the oxidative modification of lipoproteins and macrophage foam cell formation occurring in the early phase of atherosclerosis. Therefore, it is easily inferred that the changes in serum PON1 concentrations or activity can affect vascular disease status. Arylestarase (ARE) is considered as the main protein indicator which is not affected by changes in PON1. Objectives: This study was to investigate the effect of serum PON1, ARE activities relationship with stroke. Material and Methods:We evaluated and compared the PON1, ARE activity and LDL, HDL levels in 40 ischemic stroke, 33 hemorrhagic (intracerebral hemorrhage) stroke patients and 22 control patients. Moreover, the relationship between PON1 and ARE activity and other biochemical parameters were also investigated. Results: Statistical analyses revealed that PON1 activity and LDL, HDL levels were not different between groups (p=0.888, p=0.058, p=0.621, respectively), but ARE activity was found significantly lower in ischemic stroke patients compared to hemorrhagic group (p=0.010). There was no correlation between PON1 activity and HDL cholesterol in ischemic stroke patients and control group. Also there was no correlation between PON1 activity and ARE. In conclusion: HDL concentration and PON1 activity were similar between patients and control group and could not be determined as a risk factor for stroke. ARE activity was significantly lower in ischemic stroke patients compared to hemorrhagic group and control group. This study identified that ARE activity may be as important risk factor for ischemic stroke. Key words: Stroke, Paraoxonase, Arylesterase, LDL, HDL.