Effects of stress associated with academic examination on the kynurenine pathway profile in healthy students

Myint, Kyaimon and Jacobs, Kelly and Myint, Aye Mu and Lam, Sau Kuen and Henden, Lyndal and Hoe, See Ziau and Guillemin, Gilles J. (2021) Effects of stress associated with academic examination on the kynurenine pathway profile in healthy students. PLoS ONE, 16 (6). ISSN 1932-6203, DOI https://doi.org/10.1371/journal.pone.0252668.

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The effects of stress on the neuroendocrine, central nervous and immune systems are extremely complex. The kynurenine pathway (KP) of the tryptophan metabolism is recognised as a cross-link between the neuroendocrine- and immune systems. However, the effects of acute stress from everyday life on KP activation have not yet been studied. This study aims to investigate changes in the levels of the KP neuroactive metabolites and cytokines in response to stress triggered by academic examinations. Ninety-two healthy first year medical students benevolently participated in the study. Parameters were measured pre- examination, which is considered to be a high-stress period, and post-examination, as a low-stress period. Stress induced by academic examinations significantly increases the perceived stress scores (p<0.001), serum cortisol levels (p<0.001) and brain-derived neurotrophic factor (BDNF) levels (p<0.01). It decreased IL-10 levels (p<0.05) but had no effect on IL-6 and TNF-alpha levels. Only the KP neuroactive metabolite, 3-hydroxykynurenine (3-HK) significantly increased (p<0.01) in the post-examination period. In addition, the stress scores positively correlated with the levels of cortisol (r(2) = 0.297, p<0.01) at post examination. Acute stress triggered by academic examinations increases cortisol and BDNF production and suppresses the anti-inflammatory cytokine, IL-10, but did not increase significantly the levels of other pro-inflammatory cytokines, tryptophan, kynurenine and downstream KP metabolites. The concomitant increased levels of BDNF under the duress of acute examination stress appear to limit the levels pro-inflammatory markers, which may attenuate the action of cortisol and the neuroinflammatory branch of the KP.

Item Type: Article
Funders: University of Malaya Research Grant Health and Translational Medicine Cluster (RG266/10HTM), National Health and Medical Research Council (NHMRC) of Australia, Australian Research Council, Macquarie University
Uncontrolled Keywords: Quinolinic acid; Neurotrophic factor; Indoleamine 2,3-Dioxygenase; Undergraduate Students; Central mechanisms; Medical-students; Mammalian brain; Human microglia; Messenger-RNA; Expression
Subjects: R Medicine > R Medicine (General)
Divisions: Faculty of Medicine
Depositing User: Ms Zaharah Ramly
Date Deposited: 06 Apr 2022 07:29
Last Modified: 06 Apr 2022 07:29
URI: http://eprints.um.edu.my/id/eprint/28598

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