**2.1 PON1 and ischemic stroke**

Globally recognized among the common causes of death, ischemic stroke accounts for major disabilities too. It is a classical multi-factorial disease with major risk factors such as hypertension, smoking, hyperlipidemia, obesity, diabetes, and atrial fibrillation. Many studies have been conducted to search for role of PON1 in ischemic stroke. Literature reports R allele and RR genotype of Q192R PON1 polymorphism carries higher risk of ischemic stroke. Many researchers have found that decrease in activity of PON1 is associated with vascular events [25, 26]. Some report, paraoxonase and arylesterase activities and their ratio can be used either to predict or to access the severity of ischemic stroke [27, 28]. In general there is significant negative correlation of PON1 activities with adverse vascular events. Lower the activities, more advanced are the vascular lesions [29, 30].
