Neurotransmitter metabolic enzymes and antioxidant status on Alzheimer's disease induced mice treated with Alpinia galanga (L.) Willd.

Amyloid β₂₅₋₃₅ (Aβ) peptide may be neurotoxic during the progression of Alzheimer's disease by eliciting reactive oxygen species. The use of folklore medicine is prevalent and plants which possess a rejuvenating property are a large source of natural antioxidants that might afford leads for the development of novel drugs in neurodegenerative disorders. The study was designed to investigate the effect of an ethanol extract of Alpinia galanga (L.) Willd (EAG) on oxidative stress induced Alzheimer's type amnesia in mice. Mice were treated with an experimental extract at 200 mg/kg and 400 mg/kg dose for 14 days and injected with neurotoxic Aβ and the doses were continued for 21 days. Behavioural studies with open field, step-down inhibitory avoidance and a water maze after treatment indicated the acceleration in cognitive function. The elevated levels of acetylcholinesterase and monoamine oxidase enzymes in amnesia induced mice were attenuated by treatment with EAG. The generation of free radicals was decreased due increased activity of antioxidant enzymes after treatment with EAG. These findings suggested that EAG exerts an antiamnesiac effect in Aβ induced neurodegeneration through an antioxidant property.