Abstract

Icariin, one of the main active components of Epimedium brevicornum maxim, exerts extensive bioactivities of anti-oxidant stress, anti-aging and anti-tumor. However, there was only a few studies on icariin's mechanisms in alleviating the cognitive impairment. The present study investigated the potential effects of Icariin on the learning performance in a scopolamine-induced cognitive impairment mouse model. Sixty SPF-grade male mice were divided into six groups: control group, scopolamine group, donepezil group and low-, medium-, and high-dose icariin groups+scopolamine. The control and scopolamine groups were given 0.5 % calcium magnesium acetate-sodium, the donepezil group was given 2 mg/kg donepezil hydrochloride, and the low-, medium-, and high-dose icariin groups were given 30 mg/kg, 60 mg/kg and 120 mg/kg icariin, respectively. All mice were given 10 ml/kg volume by continuous gavage for 14 d. The cognitive impairment mouse model was established from the 10^th d, the control group was intraperitoneally injected with 0.9 % normal saline, the other groups were intraperitoneally injected with 2 mg/kg scopolamine hydrobromide (10 ml/kg) for five consecutive days within 30 min of the start of the behavioral experiment. Morris water maze task, new object recognition and dark avoidance experiment were performed to assess learning performance. Pathological changes in the hippocampal cornu ammonis 1 neurons were observed through hematoxylin-eosin staining. The levels of oxidative stress parameters malondialdehyde, superoxide dismutase, Glutathione, glutathione peroxidase and cholinergic system markers acetylcholinesterase, choline-acetyltransferase and acetylcholine were detected by test kits. Additionally, the levels of brain-derived neurotrophic factor (BDNF), synaptophysin, postsynaptic density-95, caspase-3, B-cell leukemia-2 associated X protein and B-cell leukemia-2 were detected by Western blots. In conclusion, the results indicate that icariin may alleviate scopolamine-induced cognitive impairment by improving oxidative stress, and regulating cell apoptosis and synaptic related protein expression. Full-Text | PDF