Free-L-Cysteine improves corticosterone-induced behavioral deficits, oxidative stress and neurotransmission in rats.

L-Cysteine (L-Cys) is a semi-essential amino acid. It serves as a substrate for enzyme cystathionine-β-synthase in the central nervous system (CNS). L-Cys showed various antioxidant characteristics. Though, studies on the effect of free L-Cys administration to evaluate the CNS functioning is very limited. Therefore, we assessed the effects of L-Cys on corticosterone (CORT) induced oxidative stress, behavioral deficits and memory impairment in male rats. L-Cys (150 mg/kg/ml) administered to vehicle and CORT (20 mg/kg/ml) treated rats orally for 28 days. Behavioral activities were conducted after treatment period. Subsequently, rats were sacrificed, blood and brain were removed. Hippocampus was isolated from brain and then hippocampus and plasma were collected for oxidative, biochemical and neurochemical analysis. Results showed that repeated treatment of L-Cys produced antidepressant, anxiolytic and memory-improving effects which may be ascribed to the enhanced antioxidant profile, normalized cholinergic, serotonergic neurotransmission in brain (hippocampus) following CORT administration. Increased plasma CORT by CORT administration was also normalized by L-Cys. The current study concluded that administration of free L-Cys improved the behavioral, biochemical, neurochemical and redox status of CNS. Hence, L-Cys could be protective therapeutic modulator against stress induced neurological ailments.