Zingiber officinale   : Evaluation of its Nootropic effect in mice

Dementia is one of the age-related mental problems, and a characteristic symptom of Alzheimer's disease. Nootropic agents and cholinesterase inhibitors like donepezil® are clinically used in situations where there is organic disorder in learning abilities and for improving memory, mood and behavior, but the resulting side-effects associated with these agents have made their utility limited. Ayurveda emphasizes use of herbs, nutraceuticals or life-style changes for controlling age related neurodegenerative disorders. The present study was undertaken to assess the potential of an ayurvedic rasayana (rejuvenator) drug Zingiber officinale Roscoe as a memory enhancer. Elevated plus maze and passive avoidance paradigm were employed to evaluate learning and memory parameters. Z. officinale extract (50 and 100 mg/kg, p.o.) were administered for 8 successive days to both young and aged mice. The dose of 100 mg/kg of Z. officinale extract significantly improved learning and memory in young mice and also reversed the amnesia induced by diazepam (1 mg/kg, i.p.), and scopolamine (0.4 mg/kg, i.p.). Furthermore, it also reversed aging induced amnesia due to natural aging of mice. Z. officinale significantly increased whole brain acetyl cholinesterase inhibition activity. Hence, Z. officinale might prove to be a useful memory restorative agent in the treatment of dementia seen in the elderly. The underlying mechanism of its action maybe attributed to its antioxidant and acetyl cholinesterase inhibition property