CAT and memory impairment: Based on the crucial role of oxidative stress and cholinergic system function on memory impairment previously mentioned, this part of study was focused on the effect of M. oleifera on oxidative stress markers including MDA level and the activities of scavenger enzymes including SOD, CAT, and GSH-Px and on the activity of AChE, an indirect indicator reflecting the available acetylcholine, in hippocampus.