Carnosine restores aging-induced elevation of corticosterone status and brain regional amyloid-beta in relation to down regulation of locomotor activity

The aim of the present investigation was to evaluate the role of carnosine on aging-induced Aβ deposition in different brain regions (prefrontal cortex, hippocampal CA1 and CA3 zones, hypothalamus, pons-medulla and cerebellum) in connection with the locomotor activity (open field locomotion and rearing count) and corticosterone status in plasma and adrenal gland. During aging, both in 18 and 24 months aged rats (a) a graded deposition of Aβ in their brain regions was observed with a maximum deposition in prefrontal cortex of 24 months aged rats without any Aβ deposition in cerebellum, (b) the plasma and adrenal corticosterone level was increased, and (c) locomotor activity were reduced. Carnosine (2.0 μg/Kg/day, i.t.; for 21 consecutive days) reduced the aging-induced brain regional graded Aβ deposition and attenuated the aging-induced increase of both plasma and adrenal corticosterone level as well as the locomotor activity. Thus, it may be concluded from these observations that (a) aging reduces both rearing and locomotor activities which may be correlated with the increase of corticosterone in both plasma and adrenal gland with a graded Aβ accumulation in the brain regions, except cerebellum and (b) carnosine attenuates these aging-induced phenomena, observed in those brain regions, plasma and adrenal gland, and also in locomotor activities. *Correspondence to: Mrinal K. Poddar, Ph.D, D.Sc, ICMR Emeritus Medical Scientist, Department of Pharmaceutical Technology, Jadavpur University, Kolkata-700032, India, E-mail: mrinalkp@yahoo.com