Neuroprotective effect of Alpinia galanga (L.) fractions on Aβ(25-35) induced amnesia in mice

Ethnopharmacological relevance: The rhizomes of Alpinia galanga (L.) Willd (Zingiberaceae), a ginger substitute for flavouring food was traditionally used as nervine tonic and stimulant. Aim of the study: This investigation is designed to screen cognitive improvement of Alpinia galanga (AG) fractions in Alzheimer's type of amnesia in mice induced by A beta((25-35)). Materials and methods: Alzheimer's disease induced mice treated with fractions (n-hexane, chloroform and ethyl acetate) of AG in 200 and 400 mg/kg. Neurotoxicity was induced by intracerebroventricular injection of A beta(((25-35))) on the 14th day of 21 days drug treatment. Open field and water maze were carried to determine habituation memory and hippocampal memory. Na+/K+-ATPase, acetylcholinesterase (AChE) and antioxidant enzymes (SOD, GPx, catalase and vitamin C) were determined in brain tissue homogenate to estimate the brain biochemical changes and its anti-amnesic potential with intensity of oxidative stress signaling. Further bioactive (chloroform) fraction was eluted through column chromatography to identify the lead molecules. Results: Increased habituation memory and decreased escape latency in behavioral parameter are the indicative of the cognitive enhancement after treatment with Alpinia galanga fractions. Increment in Na+/K+-ATPase and antioxidant activity depicts brain membrane integrity improvement and free radical scavenging property. AChE level was decreased to improve the cognition by enhancing cholinergic transmission. Conclusion: Anti-amnesic effect was exerted by various fractions of Alpinia galanga. Among all fractions, preeminent neuroprotection was exerted by chloroform fraction, which has compound, 1'delta-1'-acetoxyeugenol acetate and it may be a potential therapeutic agent for Alzheimer's type of amnesia. These results further motivate us to explore the activity of lead compound's anti-amnesic effect on transgenic mice model of AD. (C) 2011 Elsevier Ireland Ltd. All rights reserved.