Preventive effects of ellagic acid on nucleus tractus solitarius electrical activity and oxidative stress altered by cerebral global ischemia/reperfusion in rat

Abstract

Cerebral ischemia commonly occurs when the blood flow to the entire brain or some part of the brain is disrupted. Global cerebral ischemia attenuates the nucleus tractus solitaries (NTS) EEG rhythm, increases the free radicals production and brain inflammation. Ellagic acid (EA) has antioxidative and anti-inflammatory effects against neural damages. The aim of this study was to evaluate the role of ellagic acid on EEG power in the global cerebral ischemia. Rats were divided into four groups: SO (sham) received normal saline, EA+SO, I/R (normal saline + ischemia/reperfusion), and EA + I/R. EA (100 mg/kg, dissolved in normal saline) or normal saline was administered orally (gavage) for 10 days. Animal underwent to 20 minutes of ischemia followed by 30 minutes of reperfusion in I/R and I/R+EA groups. EEG was recorded from NTS and serum antioxidant enzyme activity was measured. Data showed that ellagic acid improved electrical power of NTS. Theta and delta bands frequencies in the ischemic animals were decreased in I/R group with compared to SO group significantly (P < 0.001). Ellagic acid has beneficial effect on superoxide dismutase activity in the ischemic animals with compared to I/R group (P < 0.01). In contrast, ellagic acid has no significant role on glutathione peroxidase activity in the pretreated ischemic rats in comparison with I/R group. These findings suggest that ellagic acid increased antioxidant enzymes activity that scavenge the ROS due to ischemia so that it may have neuroprotective effect on NTS neurons and consequently reverse its electrophysiology pattern.