Effects of L-Theanine on Posttraumatic Stress Disorder Induced Changes in Rat Brain Gene Expression

Abstract

Posttraumatic stress disorder (PTSD) is characterized by the occurrence of a traumatic event that is beyond the normal range of human experience. The future of PTSD treatment may specifically target the molecular mechanisms of PTSD. In the US, approximately 20% of adults report taking herbal products to treat medical illnesses. L-theanine is the amino acid in green tea primarily responsible for relaxation effects. No studies have evaluated the potential therapeutic properties of herbal medications on gene expression in PTSD. We evaluated gene expression in PTSD-induced changes in the amygdala and hippocampus of Sprague-Dawley rats. The rats were assigned to PTSD-stressed and nonstressed groups that received either saline, midazolam, L-theanine, or L-theanine + midazolam. Amygdala and hippocampus tissue samples were analyzed for changes in gene expression. One-way ANOVA was used to detect significant difference between groups in the amygdala and hippocampus. Of 88 genes examined, 17 had a large effect size greater than 0.138. Of these, 3 genes in the hippocampus and 5 genes in the amygdala were considered significant (P < 0.05) between the groups. RT-PCR analysis revealed significant changes between groups in several genes implicated in a variety of disorders ranging from PTSD, anxiety, mood disorders, and substance dependence.

l‐Theanine inhibits proinflammatory PKC/ERK/ICAM‐1/IL‐33 signaling, apoptosis, and autophagy formation in substance P‐induced hyperactive bladder in rats

“…Green tea and black tea are considered as major sources of l ‐theanine in the human diet for its wide popularity . l ‐Theanine treatment has been frequently reported to improve cognition, mood, gastric ulcer injury, and cerebral ischemia/reperfusion injury, and posttraumatic stress disorder suggesting its antioxidant, anti‐inflammatory, and relaxation effects. l ‐Theanine may regulate stress state modulation via the release or reduction of the neurotransmitters or chemicals gamma aminobutyric acid, dopamine, and serotonin…”

Investigation of Effects of L-Theanine on PTSD-induced Changes in Rat Neurobehavior

“…Total of 80 rats were randomly assigned to the two groups as described in our previous work (Ceremuga et al, 2014). Forty rats were assigned to the nonstressed groups and forty were assigned to the 3-day-restraint shock PTSD rodent groups.…”

“…Minimal data are available regarding the anxiolytic effects of L-Theanine (Lu et al, 2004). There is only one published study on the effects of L-Theanine on PTSD or regarding interactions of anxiolytics with L-Theanine that evaluated gene expression in the amygdala and hippocampus (Ceremuga et al, 2014).…”

Evaluation of the effects of L-Theanine on neurobehavior in an adult male Sprague-Dawley Rat Model of PTSD

“…Because of its ability to cross the blood brain barrier (30), L-Th had been shown to decrease anxiety by enhancing the production of the inhibitory, relaxing neurotransmitter GABA, while blocking the excitatory glutamate receptors in the brain (31). Our early study showed that L-Th affects the expression of genes in brain areas responsible for fear and aggression (amygdala) and memory (hippocampus), helping to balance the behavioral responses to PTSD (32). L-Th is also neuroprotective by preventing memory impairment (33,34).…”