Satureja bachtiarica ameliorate beta-amyloid induced memory impairment, oxidative stress and cholinergic deficit in animal model of Alzheimer's disease

Extracellular deposition of Beta-amyloid peptide (A beta) is the main finding in the pathophysiology of Alzheimer's disease (AD), which damages cholinergic neurons through oxidative stress and reduces the cholinergic neurotransmission. Satureja bachtiarica is a medicinal plant from the Lamiaceae family which was widely used in Iranian traditional medicine. The aim of the present study was to investigate possible protective effects of S. bachtiarica methanolic extract on A beta induced spatial memory impairment in Morris Water Maze (MWM), oxidative stress and cholinergic neuron degeneration. Pre- aggregated A beta was injected into the hippocampus of each rat bilaterally (10 mu g/rat) and MWM task was performed 14 days later to evaluate learning and memory function. Methanolic extract of S.bachtiarica (10, 50 and 100 mg/Kg) was injected intraperitoneally for 19 consecutive days, after A beta injection. After the probe test the brain tissue were collected and lipid peroxidation, Acetylcholinesterase (AChE) activity and Cholin Acetyl Transferees (ChAT) immunorectivity were measured in the hippocampus. Intrahipocampal injection of A beta impaired learning and memory in MWM in training days and probe trail. Methanolic extract of S. bachtiarica (50 and 100 mg/Kg) could attenuate A beta-induced memory deficit. ChAT immunostaining revealed that cholinergic neurons were loss in A beta- injected group and S. bachtiarica (100 mg/Kg) could ameliorate A beta- induced ChAT reduction in the hippocampus. Also S. bachtiarica could ameliorate A beta-induced lipid peroxidation and AChE activity increase in the hippocampus. In conclusion our study represent that S.bachtiarica methanolic extract can improve A beta-induced memory impairment and cholinergic loss then we recommended this extract as a candidate for further investigation in treatment of AD.