Beta-Asarone Improves Cognitive Function by Suppressing Neuronal Apoptosis in the Beta-Amyloid Hippocampus Injection Rats

Elevated levels of β-amyloid (Aβ) in the brains being a hallmark of Alzheimer's disease (AD) have been believed to play a critical role in the cognitive dysfunction that occurs in AD. Recent evidence suggests that Aβ induces neuronal apoptosis in the brain and in primary neuronal cultures. In this study, we investigated the effects of β-asarone, the major ingredient of Acorus Tatarinowii Schott, on cognitive function and neuronal apoptosis in Aβ hippocampus injection rats and its mechanism of action. The results show that the Aβ (1—42) injection caused impairments in spatial reference memory in a Morris water maze task and apoptosis in hippocampus. Oral administration of β-asarone with three different dose (12.5, 25, or 50 mg/kg) for 28 d ameliorated Aβ (1—42)-induced cognitive impairment and reversed the increase of apoptosis in the hippocampus. Aβ-induced c-Jun N-terminal kinase (JNK) results in phosphorylation, subsequent down-regulation of Bcl-2 and Bcl-w expression, and caspase-3 activation. Beta-asarone attenuate Aβ (1—42)-induced neuronal apoptosis in hippocampus by reversal down-regulation of Bcl-2, Bcl-w, caspase-3 activation, and JNK phosphorylation. These results suggest that β-asarone may be a potential candidate for development as a therapeutic agent to manage cognitive impairment associated with conditions such as Alzheimer's disease.