Beneficial Effect of Oryzanol on Transient Middle Artery Occlusion Induced Ischemic Stroke in Atherosclerotic Rats. Improvement in Behavioural and Biochemical Parameters

Abstract

The present study was designed to determine the beneficial effect of oryzanol treatment in the ischemic stroke in atherosclerotic rats. Atherosclerosis was induced in rats using high fat diet (containing 20% ground nut oil, 0.5% cholesterol, 1% cholic acid) for 32 days. Ischemic stroke was induced in the atherosclerotic rat (AT rats) on 33^rd day using tMCAO model. In the oryzanol treatment group, oryzanol (100 mg/kg, po) was administered on the very first day (day rats were fed with high fat diet), ischemic stroke was induced on 33^rd day and oryzanol treatment was continued after the induction of ischemia from 34^th day to 40^th day. The neurological score was determined for 7days with gap of 24 hrs between the testing procedure. Rats were sacrificed followed by the blood collection and excision of whole brain for the determination of various parameters including brain damage (infarct volume, brain hemisphere weight difference, and Na⁺-K⁺-ATPase activity) and oxidative stress parameter (SOD activity, reduced GSH level, MDA level, nitrite level and LDH level). It was observed that ischemia-reperfusion (IR rats) in atherosclerotic rats increased the neurological score, increase in infarct volume, brain hemisphere weight difference and reduced activity of Na⁺-K⁺-ATPase. Further IR rats showed the decreased activity of SOD activity and GSH, whereas the level of MDA, nitrite and LDH activity was found to be increased in the atherosclerotic-IR rats. Further it was observed that the oryzanol treatment in the atherosclerotic counteracted the high fat induced rise in the TG, LDL, and VLDL level and increased the level of HDL in the treated animals. Further the administration of oryzanol improved the neurological score, reduce the infarct volume, brain hemisphere weight difference and improve the activity of Na⁺-K⁺-ATPase. Oryzanol treatment further improved the SOD activity, increased the level of GSH, reduced the level of MDA, nitrite and LDH activity in atherosclerotic-IR rats