β-Alanine supplementation reduces anxiety and increases neurotrophin expression in both young and older rats

Abstract

The effect of 30 days of β-alanine supplementation (100 mg/kg) on behavioral response and expression of brain-derived neurotrophic factor (BDNF), neuropeptide Y (NPY), and markers of inflammation was examined in both young (4 months) and older (14 months) rats. We hypothesized that animals fed β-alanine would experience reduced inflammation and an enhanced neurotrophin and behavioral response. Animals were assigned to either a control group, in which young or older rats were fed regular chow and water, or a β-alanine group, in which rats were fed regular chow and provided β-alanine in their water. Behavior measures were conducted following the 30-day supplementation period, which included spatial learning, memory, and an anxiety index. Hippocampal expressions of BDNF, NPY, glial fibrillary acidic protein, nuclear factor–κB p50 and p65 subunits, tumor necrosis factor–α, and cyclooxygenase-2 were also analyzed. Learning ability was reduced (P = .001) and anxiety index was higher (P = .001) in older compared to young rats. Similarly, BDNF and NPY expressions were reduced and all inflammatory markers were elevated (P < .05) in the older animals. β-Alanine increased BDNF expressions in the cornu ammonis area 1 (P = .003) and 3 (P < .001) subregions of the hippocampus. BDNF expression for younger rats in the β-alanine group was also significantly greater than younger rats in the control group in cornu ammonis area 3. Learning for young animals fed β-alanine was significantly better than all other groups. Significant reductions in anxiety were noted in both older and younger rats fed β-alanine compared to age-matched controls. Results indicated that β-alanine ingestion in both young and older rats was effective in attenuating anxiety and augmenting BDNF expression in the hippocampus.