Neuroprotective Role of Total Oligomeric Flavonoids of Cyperus Rotundus in Rat Model of Transient Focal Ischemia

Abstract

Stroke is the second most common single cause of death in newlinedeveloped countries after ischemic heart disease and largest cause of newlinedisability worldwide (1, 2). Brain tissue is exquisitely sensitive to ischemia, newlinesuch that even brief ischemic episodes to neurons can initiate a complex newlinesequence of events that ultimately may culminate in cellular death. newlineDifferent brain structures have varying thresholds for ischemic cell newlinedamage, with white matter being more resilient than gray matter (3). Brain newlineexclusively dependents on the continuous delivery of oxygen and glucose newlinethrough blood flow, and interruption of the cerebral blood supply newlineexacerbates irretrievable damage (4). The major pathobiological newlinemechanisms of ischemia/reperfusion (IR) injury include excitotoxicity, newlineoxidative stress, inflammation and apoptosis (5-8). newlineFocal ischemia entails reduction in cerebral blood flow (CBF) to a newlinespecific vascular territory, usually encountered due to thrombotic/embolic newlineor hemorrhagic blocks (9). The tissue in the center of ischemic area with newlinesevere CBF reduction is termed as ischemic core. Circumference of newlineischemic core where the blood flow is normal, the ischemic injury becomes newlineprogressively less severe. This peripheral region of the ischemic territory is newlinecalled ischemic penumbra (Fig 1.1). In all cases, the stroke ultimately newlineinvolves dysfunction or death of brain cells, giving rise to cerebralinfarction. Depending on the loci and size of the infarct, stroke may lead to newlineneurological deficits or in severe cases, death. newlineWorld Health Organization (WHO) data shows 5.7 million deaths newlinefrom cerebrovascular diseases out of 58 million global deaths in 2005. The newlinenumber of people with transient ischemic attack (TIA) is estimated to be newlineeven greater (10). It is estimated that stroke is responsible for about newline102000 deaths annually in India, which represent about 2% of the total newlinedeaths in the country (11). newlineAnalysis of community surveys from different regions of India shows newlinea crude stroke prevalence rate of about 203 per 100,000 populations newlineabove 20 y