Modulation of monoamines and amino-acids neurotransmitters in cerebral cortex and hippocampus of female senile rats by ginger and lipoic acid

Abstract

Brain aging is the major risk factor for common neurodegenerative diseases. Free radicals are involved in 
neurodegenerative disorders such as aging. Several neural systems are affected in aging. Neurotransmitters 
exhibited a marked alteration in different regions of the brain as part of the normal aging process. In the present 
study, age-related changes in the levels of monoamines and amino-acids neurotransmitters in normal female senile 
rats and the effect of oral administration of two antioxidants lipoic acid (LA) and ginger for 30 days accumulation on 
the neurotransmitters in the brain areas (hippocampus and cerebral cortex) is investigated. The levels of 
hippocampal monoamines [norepinephrine (NE) and serotonin 5-HT] and cortical dopamine (DA) and 5- HT were 
increased after administration of LA while, no significant differences were found in cortical monoamines compared 
with senile female rats. On the other hand, the levels of hippocampal DA, 5- HT and NE were increased after 
administration of ginger while, no statistical difference were found in cortical monoamines after administration of 
ginger compared with the adult ones. Furthermore, the effect of LA and ginger on the amino-acid profile in female 
senile rats was impressive. There were significant and remarkable increases in hippocampal glutamic, aspartic, 
GABA and cortical glutamic, aspartic, glycine and alanine compared with the levels of senile female rats. Ginger 
supplementation showed increased the amino-acids in the hippocampus (glutamic, aspartic, GABA and alanine) 
significantly as well as cortical aspartic, glycine, GABA and alanine compared with the normal senile female rats. In 
conclusion, LA and ginger may have shown a significant ameliorative value in counteracting age induced deficiency 
in some brain areas of female aged rats via modulating the investigating monoamines and amino acids in the brain 
cortex and hippocampus.