Protective effect of menthol on β-amyloid peptide induced cognitive deficits in mice.

Cognitive impairment is a multidimensional concept that subsumes the attention and concentration, learning and memory, problem-solving ability, visuospatial abilities, mental flexibility, psychomotor efficiency and manual dexterity. The intrinsic mechanisms of the behavioural effects may involve neuronal damage in the brain structure. A lower concentration of glutamate receptor co-agonists in the striatum indicates the general malfunction of the brain glutamatergic system. It is suggested that a selective decrease in hippocampal glutamate concentration may account for deterioration in learning and memory process, considering the important role of this neurotransmitter in the cognitive functions. Nootropic agents like piracetam and anticholinesterase inhibitors are commonly used for improving memory, mood and behaviours. The present study was undertaken to assess the nootropic potential of menthol on learning and memory employing exteroceptive and interoceptive behavioral model in young and aged mice. To delineate the mechanism by which menthol decreases cognitive impairment and protect the brain, various biochemical parameters such as brain glutamate, glycine, glutathione and thiobarbituric acid reactive substances were determined. Menthol produced significant improvement in learning and memory. Menthol exhibited excellent antioxidant effect and maintain glutamate concentration in various region of the mouse brain for management of preliminary symptoms of memory impairment.