Effects of Sleep Deprivation on the Tryptophan Metabolism

Abstract

Sleep has a regulatory role in maintaining metabolic homeostasis and cellular functions. Inadequate sleep time and sleep disorders have become more prevalent in the modern lifestyle. Fragmentation of sleep pattern alters critical intracellular second messengers and neurotransmitters which have key functions in brain development and behavioral functions. Tryptophan metabolism has also been found to get altered in SD and it is linked to various neurodegenerative diseases. The kynurenine pathway is a major regulator of the immune response. Adequate sleep alleviates neuroinflammation and facilitates the cellular clearance of metabolic toxins produced within the brain, while sleep deprivation activates the enzymatic degradation of tryptophan via the kynurenine pathway, which results in an increased accumulation of neurotoxic metabolites. SD causes increased production and accumulation of kynurenic acid in various regions of the brain. Higher levels of kynurenic acid have been found to trigger apoptosis, leads to cognitive decline, and inhibit neurogenesis. This review aims to link the impact of sleep deprivation on tryptophan metabolism and associated complication in the brain.

Acetylsalicylic acid improves cognitive performance in sleep deprived adult Zebrafish (Danio rerio) model

“…SD is one of the major risk factors that impair learning and memory. Adverse changes in cognitive performance have been associated with total and partial SD [6]. In the present study, fish exposed to extended light phase and light pulses showed decreased locomotor strength in partition preference and spinning task and increased working errors in T-maze tests, signifying the induction of SD.…”

“…Normal sleeping pattern induces long term potentiation (LTP), synaptic plasticity and promotes memory formation [5]. Sleep Deprivation (SD) is reduction in sleeping time below the baseline requirement [6] which is reported to cause learning and memory deficits [7]. Although the exact pathogenetic mechanism of action of SD on memory impairment remains elusive, over activation of microglial cells and increased nuclear factor (NF-κB) in turn levels of proinflammatory cytokines such as Interleukin 1 beta (IL-1β), Interleukin 6 (IL6), tumor necrosis factor alpha (TNF-α) are reported as crucial factors [8].…”

A comprehensive study on the relieving effect of Lilium brownii on the intestinal flora and metabolic disorder in p -chlorphenylalanine induced insomnia rats

“…Insomnia is known to cause disorders in tryptophan metabolism (Bhat et al. 2020 ). It can be seen from the results of differential metabolites that the tryptamine in the PCPA group was significantly reduced, while the N -γ-acetyl- N -2-formyl-5-methoxykynurenamine (AFMK), as the enzymatic degradation production of 5-HT, was elevated.…”

Vitamin C and E Treatment Blocks Changes in Kynurenine Metabolism Triggered by Three Weeks of Sprint Interval Training in Recreationally Active Elderly Humans

“…In this context, it is intriguing that the effect was obtained with a total of only 7–9 min of high-intensity exercise per week. Furthermore, the effect seems robust in that it was statistically significant with the limited number of individuals included in the study and without full control of diet and sleep, factors that can affect the concentration of KP metabolites [ 46 , 47 ].…”