• Journal of Nutrition and Health
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• v.27 no.2
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• pp.153-161
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• 1994

We fed high trypotophan diet(3.5% tryptophan/diet(w/w) to mice for 7 days and treated then with 3 hour immobilization(IMMB) stress to investigate tryptophan metabolism and immunomodulation. The levels of serum tryptophan, brain tryptophan, serotonin(5HT) and 5-hydroxyindoleacetic acid(5HIAA) in the tryptophan diet fed animals were higher than those of the normal diet fed animals. Feeding tryptophan supplemented diet to stressed animal significantly decreased the levels of serum and brain tryptophan and 5HT levels. However, the amount of 5HIAA which is the metabolite of serotonin was increased in brain. Plasma corticosterone level was increased by the stress in both groups but the degree of this increase was smaller in high tryptophan fed animals. The relative numbers of CD8+ T cells, CD4+ T cells and B cells in spleen were decreased in high tryptophan diet fed and stressed animals compared to control diet fed and no stressed animals. CD8+ T cells decreased more than CD4+ T cells. The decrease of CD8+ T cells in high tryptophan fed and stressed animals was similar to that in high tryptophan fed animals or normal diet fed and stressed animals. Stress and tryptophan supplement acted synergistically to decrease the number of B cells. This study suggests that stress and tryptophan supplement could modify the number of lymphocyte cells, and indicates that the interaction of stress and tryptophan supplement on immune fuction depends on the types of immune cells.

• Journal of Nutrition and Health
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• v.26 no.3
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• pp.231-247
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• 1993

This study was designed to confirm the effect of dietary protein level and oral administration of tryptophan on brain serotonin metabolism. Two animal experiments were conducted. The objectives and results of research were as follows : In the first experiment, it was investigated whether administration of reserpine to Sprague-Dawley rats fed 6% or 20% casein diet induced decrease in serum tryptophan and large neutral amino acid(LNAA) concentrations, tryptophan/LNAA concentration ratio, brain tryptophan, serotonin and 5-hydroxyindoleacetic acid(5-HIAA) contents. Brain serotonin content of 6% casein diet group was lower than those of 20% casein diet group. Both 6% and 20% casein diet groups administered with reserpine to induce the analogous depression, showed the notable decrease in brain serotonin content when they were compared with 20% casein diet group not administered with reserpine. Serum tryptophan/LNAA ration and brain 5-HIAA content showed a tendency similar to the change of serotonin content, but the mean difference among all groups was not significant. From these results, it could be said that when the dietary protein level was low, brain serotonin content was decrease. The second experimnt was to see the change in serum tryptophan concentration and tryptophan/LNAA ratio and brain tryptophan, serotonin and 5-HIAA content when tryptophan was administered orally to the animals treated with reserpine. Serum tryptophan concentration tended to increase in both reserpine-treated 6% and 20% casein diet groups administered with tryptophan, especially in the 6% casein diet group. Serum tryptophan/LNAA concentration ratio tended to incrase in reserpine-tteated 6% casein diet group, while decrease in reserpine-treated 20% casein diet group. Brain tryptophan content was increased in both reserpine-treated 6% and 20% casein diet groups. However, brain serotonin content of reserpine-treated 6% casein diet group showed a tendency to decrease, while that of reserpine-treated 20% casein group increase. Consequently, the effect of tryptophan administration on increase of brain tryptophan and serotonin content in animals treated with reserpine was far more excellent in 20% casein diet groups. It was concluded that dietary protein intake and tryptophan administration increase brain serotonin level. Accordingly, it was possible to confirm that brain function, particularly in aspect of behavior related to the serotonin, was changed with manipulation of dietary composition.

• Biomolecules & Therapeutics
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• v.9 no.1
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• pp.20-25
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• 2001

In this study we fed control diet and tryptophan supplemented diets containing 0.35% tryptophan to ICR mice for 2 weeks. The concentrations of serotonin and 5-HIAA were changed by injection of the serotonin synthesis inhibitor, p-CPA and the serotonin precursor, serotoninP and the change of brain serotonin concentration negatively correlated with that of pain sensitivity, and p-CPA and serotoninP also changed the analgesic effect of morphine. The injection of naloxone, the opiate antagonist, resulted in an increase in the writhing frequency, but its antagonistic effect was not significant. The concentration of 5-HIAA elevated in mice brain at least 3hr after administration of morphine hydroxide indicates that the changes in brain serotonin metabolism may be associated with the acute effects of morphine analgesia. In short, these results not only suggest that tryptophan supplemented diet suppress pain sensitivity in mice, but also indicate that at least in part analgesic mechanism of serotonin may be associated with morphine analgesia.

• The Korean Journal of Physiology and Pharmacology
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• v.18 no.3
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• pp.233-239
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• 2014

The present study was designed to investigate the effect Hypericum Perforatum (HP), on behavioral changes, corticosterone, TNF-${\alpha}$ levels and tryptophan metabolism and disposition in bilateral ovariectomized rats compared to $17{\alpha}$-ethinylestradiol. Behavioral analysis by measuring immobility time in forced swimming test and open field test, serum and hippocampal corticosterone and TNF-${\alpha}$ along with hippocampal kynurenine/tryptophan ratio were determined in mature ovariectomized rats treated orally either by HP at three different doses 125, 250, and 500 mg/kg/day or by $17{\alpha}$-ethinylestradiol $30{\mu}g/kg/day$ for 30 days. Ovariectomized rats showed significant increase in immobility time in the forced swimming test. Along with elevation in serum and hippocampal TNF-${\alpha}$ and corticosterone levels associated with significant increase in hippocampal kynurenine/tryptophan ratio. Immobility time in the forced swimming test was decreased in rats treated by different doses of HP in a dose dependent manner and $17{\alpha}$-ethinylestradiol with no concomitant changes in the open field test. Only Rats treated with HP exhibited significant decrease in the elevated serum and hippocampal TNF-${\alpha}$ and corticosterone, which couldn't explain the associated insignificant effect on hippocampaus kynurenine/tryptophan ratio in comparison to ovariectomized untreated rats. It is concluded that increased tryptophan metabolism toward kynurenine secondary to elevated corticosterone and TNF-${\alpha}$ might be one of the pathohphysiological mechanisms that could explain depression like state observed in this rat model. Further, the observed attenuating effect of HP on TNF-${\alpha}$ and corticosterone could contribute in its antidepressant effect in this animal model by other ways than their effects on tryptophan-kynurenine metabolism pathway.

• Biomolecules & Therapeutics
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• v.8 no.4
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• pp.311-317
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• 2000

In this study we fed control diet and tryptophan supplemented diets containing 0.1,0.2,0.35% tryptophan to ICR mice for 1∼3 weeks to investigate the effects of tryptophan supplemented diet on pain sensitivity and the analgesic mechanism of serotonin. Animals fed tryptophan supplemented diets displayed increased antinociception when measured with hot plate and phenylquinone-writhing tests. And animals with typtophan supplemented diet had higher brain serotonin and 5-HIAA concentration than the control animals.

• Journal of Microbiology and Biotechnology
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• v.33 no.12
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• pp.1657-1670
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• 2023

This study aimed to evaluate the effects of Limosilactobacillus fermentum and Lactiplantibacillus plantarum isolated from human feces coordinating with inulin on the composition of gut microbiota and metabolic profiles in db/db mice. These supplements were administered to db/db mice for 12 weeks. The results showed that the Lactobacillaceae coordinating with inulin group (LI) exhibited lower fasting blood glucose levels than the model control group (MC). Additionally, LI was found to enhance colon tissue and increase the levels of short-chain fatty acids. 16S rRNA sequencing revealed that the abundance of Corynebacterium and Proteus, which were significantly increased in the MC group compared with NC group, were significantly decreased by the treatment of LI that also restored the key genera of the Lachnospiraceae_NK4A136_group, Lachnoclostridium, Ruminococcus_gnavus_group, Desulfovibrio, and Lachnospiraceae_UCG-006. Untargeted metabolomics analysis showed that lotaustralin, 5-hydroxyindoleacetic acid, and 13(S)-HpODE were increased while L-phenylalanine and L-tryptophan were decreased in the MC group compared with the NC group. However, the intervention of LI reversed the levels of these metabolites in the intestine. Correlation analysis revealed that Lachnoclostridium and Ruminococcus_gnavus_group were negatively correlated with 5-hydroxyindoleacetic acid and 13(S)-HpODE, but positively correlated with L-tryptophan. 13(S)-HpODE was involved in the "linoleic acid metabolism". L-tryptophan and 5-hydroxyindoleacetic acid were involved in "tryptophan metabolism" and "serotonergic synapse". These findings suggest that LI may alleviate type 2 diabetes symptoms by modulating the abundance of Ruminococcus_gnavus_group and Lachnoclostridium to regulate the pathways of "linoleic acid metabolism", "serotonergic synapse", and" tryptophan metabolism". Our results provide new insights into prevention and treatment of type 2 diabetes.

• The Plant Pathology Journal
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• v.30 no.2
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• pp.220-227
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• 2014

The GacS/GacA system in the root colonizer Pseudomonas chlororaphis O6 is a key regulator of many traits relevant to the biocontrol function of this bacterium. Proteomic analysis revealed 12 proteins were down-regulated in a gacS mutant of P. chlororaphis O6. These GacS-regulated proteins functioned in combating oxidative stress, cell signaling, biosynthesis of secondary metabolism, and secretion. The extent of regulation was shown by real-time RT-PCR to vary between the genes. Mutants of P. chlororaphis O6 were generated in two GacS-regulated genes, trpE, encoding a protein involved in tryptophan synthesis, and prnA, required for conversion of tryptophan to the antimicrobial compound, pyrrolitrin. Failure of the trpE mutant to induce systemic resistance in tobacco against a foliar pathogen causing soft rot, Pectobacterium carotovorum SCCI, correlated with reduced colonization of root surfaces implying an inadequate supply of tryptophan to support growth. Although colonization was not affected by mutation in the prnA gene, induction of systemic resistance was reduced, suggesting that pyrrolnitrin was an activator of plant resistance as well as an antifungal agent. Study of mutants in the other GacS-regulated proteins will indicate further the features required for biocontrol-activity in this rhizobacterium.

• Proceedings of the Korean Society of Crop Science Conference
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• 2020.06a
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• pp.103-103
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• 2020

• Journal of Microbiology and Biotechnology
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• v.10 no.6
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• pp.789-796
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• 2000

In order to analyze the effects of tktA, $aroF^{FBR}$, and aroL expression in a tryptophan-producing Escherichia coli, a series of plasmids carrying the genes were constructed. Introduction of tktA, $aroF^{FBR}$, and aroL into the E. coli strain resulted in approximately 10-20 fold increase in the activities of transketolase, the feedback inhibition-resistant 3-deoxy-D-arabinoheptulsonate-7-phosphate synthase, and shikimate kinase. Expression of $aroF^{FBR}$ in the aroB mutant strain of E. coli resulted in the accumulation of 10 mM of 3-deoxy-D-arabinoheptulsonate-7-phosphate (DAHP) in the medium. Simultaneous expression of tktA and $aroF^{FBR}$ in the strain further increased the amount of excreted DAHP to 20 mM. In contrast, the mutant strain which has no gene introduced accumulated 0.5 mM of DAHP. However, the expression of tktA and $aroF^{FBR}$ in a tryptophan-producing E. coli strain did not lead to the increased production of tryptophan, but instead, a significant amount of shikimate, which is an intermediate in the tryptophan biosynthetic pathway, was excreted to the growth medium. Despite the fact that additional expression of shikimate kinase in the strain could possibly remove 90% of excreted shikimate to 0.1 mM, the amount of tryptophan produced was still unchanged. Removing shikimate using a cloned aroL gene caused the excretion of glutamate, which suggests disturbed central carbon metabolism. However, when cultivated in a complex medium, the strain expressing tktA, $aroF^{FBR}$, and aroL produced more tryptophan than the parental strain. These data indicate that additional rate-limiting steps are present in the tryptophan biosynthetic pathway, and the carbon flow to the terminal pathway is strictly regulated. Expressing tktA in E. coli cells appeared to impose a great metabolic burden to the cells as evidenced by retarded cell growth in the defined medium. Recombinant E. coli strains harboring plasmids which carry the tktA gene showed a tendency to segregate their plasmids almost completely within 24h.

• Journal of Plant Biology
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• v.39 no.4
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• pp.243-247
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• 1996

Phosphoribosylanthranilate transferase (PAT) catalyzes the second step of the tryptophan biosynthetic pathway and is encoded by a single-copy gene that complements all the visible phenotypes of the tryptophan mutant (trp1-100) of Arabidopsis. The trp1-100 is blue fluorescent under UV light becuase it accumulates anthranilate. To obtain a plant with reduced PAT activity, PAT1 genes with several internal deletions in different promoter regions (pHS 101, pHS102, pHS104, pHS105, and pHS107) were induced into trp1-100 via Agrobacterium. Then, homozygous T3 plants were isolated and examined for blue fluorescence. Introduction of the PAT1 gene fusants results in the reversion of fluorescence phenotype except in the case of pHS105. These results prompted us to perform a parallel analysis of anthranilate synthase and PAT interms of the genetic complementation. A plant line carrying pHS105 gene fusant does not completely complement the blue fluorescence but it accumulates less anthranilate than trp1-100. The activity of PAT was reduced in the transgenic mutant as well. The plant carrying these constructs will add to the growing collection of molecular tools for the study of the indolic secondary metabolism.