Tryptophan as a Link between Psychopathology and Somatic States

Liu

Biological & Pharmaceutical Bulletin

et al. 2015

Postoperative fatigue syndrome (POFS) is a common complication which decelerates recovery after surgery. The present study investigated the anti-fatigue effect of ginsenoside Rb1 (GRb1) through the inflammatory cytokine-mediated N-methyl-D-aspartate (NMDA) receptor pathway. A POFS rat model was created by major small intestinal resection and assessed with an open field test. Real-time quantitative polymerase chain reaction, western blot analysis, high performance liquid chromatography and a transmission electron microscopic analysis were used to determine typical biochemical parameters in the hippocampus. Our results showed that POFS rats exhibited fatigue associated with an increased expression of inflammatory cytokines and NMDA receptor 1, higher (kynurenine)/(tryptophan) and (kynurenine)/(kynurenic acid) on postoperative days 1 and 3, and an increased expression of indoleamine 2,3-dioxygenase (IDO) on postoperative day 1. Degenerated neurons were found in the hippocampus of POFS rats. The NMDA receptor antagonist MK801 had a significant effect on central fatigue on postoperative day 1. GRb1 had no effect on IDO or tryptophan metabolism, but exhibited a significant effect on POFS by inhibiting the expression of inflammatory cytokines and NMDA receptor 1. These data suggested that inflammatory cytokines could activate tryptophan metabolism to cause POFS through the NMDA receptor pathway. GRb1 had an anti-fatigue effect on POFS by reducing inflammatory cytokines and NMDA receptors.

Section: Discussionmentioning

confidence: 52%

Prevention of Postoperative Fatigue Syndrome in Rat Model by Ginsenoside Rb1 <i>via</i> Down-Regulation of Inflammation along the NMDA Receptor Pathway in the Hippocampus

Liu

Biological & Pharmaceutical Bulletin

et al. 2015

“…Proteins and its peptides have been shown to inhibit the angiotensin-converting enzyme (ACE), antimicrobial activity, antioxidant activity, anti-carcinogenic activity, hypocholesterolemic effect, reduced serum triglycerides, increased lean muscle mass, protection against pathogens, regulation of blood glucose levels, and satiety effects (Chatterton et al 2006;Severin and Xia 2005;Seyler et al 2007). The branched-chain amino acids, leucine, isoleucine and valine participate in a variety of important biological functions in the brain, including those from tryptophan and tyrosine (Harris et al 2005;Russo et al 2003). There are many other types of protein found in legumes including various enzymes, protease inhibitors and lectins, which are collectively known as antinutritional compounds (ANCs).…”

Section: Nutrient Bioactive Compoundsmentioning

confidence: 99%

Horse gram- an underutilized nutraceutical pulse crop: a review

Prasad

Singh

2014

J Food Sci Technol

Horse gram is an underutilized pulse crop grown in wide range of adverse climatic conditions. It occupies an important place in human nutrition and has rich source of protein, minerals, and vitamins. Besides nutritional importance, it has been linked to reduced risk of various diseases due to presence of non-nutritive bioactive substances. These bioactive substances such as phytic acid, phenolic acid, fiber, enzymatic/proteinase inhibitors have significant metabolic and/or physiological effects. The importance of horse gram was well recognized by the folk/alternative/traditional medicine as a potential therapeutic agent to treat kidney stones, urinary diseases, piles, common cold, throat infection, fever etc. The inception of nutraceutical concept and increasing health consciousness the demand of nutraceutical and functional food is increased. In recent years, isolation and utilization of potential antioxidants from legumes including horse gram are increased as it decreases the risk of intestinal diseases, diabetes, coronary heart disease, prevention of dental caries etc. Keeping in view the increasing demand of food having nutraceutical values, the present review ascribed with recent scientific knowledge towards the possibilities of exploring the horse gram, as a source of food and nutraceuticals compounds.

“…16 IDO activity is mainly induced by the proinflammatory cytokine IFN-g and converts TRP into kynurenine (KYN), which, in the case of overstimulation, may lead to lowered TRP concentrations. 15,17 KYN is further metabolized into a series of compounds (see Figure 1), some with neurotoxic properties. 3-Hydroxykynurenine (3-OH-KYN) leads to the production of reactive oxygen species that initiate neuronal apoptosis.…”

mentioning

confidence: 99%

IDO and interferon-α-induced depressive symptoms: a shift in hypothesis from tryptophan depletion to neurotoxicity

et al. 2004

Studies show that administration of interferon (IFN)-a causes a significant increase in depressive symptoms. The enzyme indoleamine 2,3-dioxygenase (IDO), which converts tryptophan (TRP) into kynurenine (KYN) and which is stimulated by proinflammatory cytokines, may be implicated in the development of IFN-a-induced depressive symptoms, first by decreasing the TRP availability to the brain and second by the induction of the KYN pathway resulting in the production of neurotoxic metabolites. Sixteen patients with chronic hepatitis C, free of psychiatric disorders and eligible for IFN-a treatment, were recruited. Depressive symptoms were measured using the Montgomery Asberg Depression Rating Scale (MADRS). Measurements of TRP, amino acids competing with TRP for entrance through the blood-brain barrier, KYN and kynurenic acid (KA), a neuroprotective metabolite, were performed using high-performance liquid chromatography. All assessments were carried out at baseline and 1, 2, 4, 8, 12 and 24 weeks after treatment was initiated. The MADRS score significantly increased during IFN-a treatment as did the KYN/TRP ratio, reflecting IDO activity, and the KYN/KA ratio, reflecting the neurotoxic challenge. The TRP/CAA (competing amino acids) ratio, reflecting TRP availability to the brain, did not significantly change during treatment. Total MADRS score was significantly associated over time with the KYN/KA ratio, but not with the TRP/CAA ratio. Although no support was found that IDO decreases TRP availability to the brain, this study does support a role for IDO activity in the pathophysiology of IFN-a-induced depressive symptoms, through its induction of neurotoxic KYN metabolites. Molecular Psychiatry (2005) 10, 538-544.