Effect of α-asarone on ethanol-induced learning and memory impairment in mice and its underlying mechanism

Learning and memory impairment is a common symptom in the early stages of various types of dementia. It is likely to reduce the incidence of dementia with correct intervention. α-Asarone is the main bioactive substance isolated from Acorus tatarinowii Schott and has been proven to improve memory dysfunction; however, at present, the specific underlying mechanism is poorly understood. The aim of the present study was to investigate the effect of α-asarone on ethanol-impaired cognitive ability and explore the underlying mechanism in mice.

A mouse model of impaired learning and memory was created by ethanol (2.0 g/kg, i.g.). α-Asarone (7.5, 15 or 30 mg/kg, i.p.) was delivered 10 min prior to ethanol administration. The behavioral effect of α-asarone was evaluated using the novel object recognition test. Glutamate (Glu) and γ-aminobutyric acid (GABA) levels in the hippocampus were determined by ELISA, and the protein expression levels of hippocampal GluR2, NMDAR2B, SYNΙ, GLT-1 and CaMKⅡ were detected by western blotting.

Pretreatment with α-asarone significantly improved the behavioral performance, regulated the imbalance of Glu and GABA in the hippocampus and the abnormal expression of related proteins. A possible underlying mechanism is regulation of the calcium signaling cascade to correct functioning of related proteins, and thus, maintain the level of Glu.

Our results show that the improvement in learning and memory elicited by α-asarone may providing a possible novel candidate for the prevention of learning and memory impairment in the early stages of dementia.