A Focus on the Effect of L-Theanine on Improving Depression and Cognition in C57BL/J Male Mice Subjected for Chronic Stress Induced Neuroinflammation
Boddu V. S. Chandrasekhar1, Elango P1, S.Uma Maheswari2 and D. Rajukumar31Department of Pharmacology, Sri Ramachandra Medical College and Research Institute, Sri Ramachandra University, Porur, Chennai-600116, India.
2Department of Pharmacology, Faculty of Pharmacy, Sri Ramachandra University, Porur, Chennai – 600116, India.
3Department of Physiology, Rajah Muthiah Medical College, Annamalai University, Chidambaram, Tamil Nadu, India.
Corresponding Author E-mail : drpelango@yahoo.com
Abstract: A long term stressful event in life altering immune system is a major factor for the development of psychopathological conditions. By now it’s clear that stress induced neuroinflammatory cytokines are the key role in mediating neurochemical and neuroendocrine systems causing the behavioral disorders and cognitive impairment. Current anti depressants are unable to correct neurotransmitters levels directly or indirectly by inhibiting cytokines expression. Present study was conducted to elucidate the effect and mechanism of L-theanine on chronic restrainer stress (CRS) induced neuroinflammation, anxiety-like, depression, learning and memory impairment in C57BL/J male mice. Chronic restrain stress was induced by well ventilated 50ml conical tube for 6 hours/day 21 consecutive days. After stressor cessation behavioral and recognition tests were conducted, at the end of study mice were sacrificed, brain and blood was collected. Cytokines (TNF-α and IL-6), neurotransmitters were quantified in prefrontal cortex and estimated corticosterone levels in plasma. Histopathological examination of the hippocampus was performed. The results was implicated that L-theanine significantly (p<0.05) reversed the effect of CRS induced behavioral changes and memory impairment, reduced cytokines expression and restored neurotransmitter levels in prefrontal cortex. It also alleviated neuronal apoptosis and lowered the corticosterone levels in plasma of CRS mice. These results indicate that L-theanine exerted protective effect on chronic stress induced neuroinflammation, anxiety, depression and cognitive dysfunction. The mechanism of protective effect is by reducing cytokine expression in frontal cortex and preventing hippocampal apoptosis.
Keywords: Stress; Neuro-inflammation; Depression; Cognition; L-theanine Back to TOC