Tyrosine Supplementation A Nutraceutical Approach to Counter  Heat Stress Induced Cognitive Decline

Krishna Kishore; Koushik Ray; Sanjeev Kumar; J.P. Anand; Lalan Thakur; D. Ravi; A. Suresh; Radhakrishna Kolpe; Jayathilakan Kizhekkedath; Bhuvnesh Kumar; Usha Panjwani

doi:10.14429/dlsj.6.15870

Krishna Kishore DRDO-Defence Institute of Physiology and Allied Sciences (DIPAS), Timarpur, Delhi – 110 054, India https://orcid.org/0000-0002-7638-2610
Koushik Ray DRDO-Defence Institute of Physiology and Allied Sciences (DIPAS), Timarpur, Delhi – 110 054, India https://orcid.org/0000-0002-2371-6285
Sanjeev Kumar DRDO-Defence Institute of Physiology and Allied Sciences (DIPAS), Timarpur, Delhi – 110 054, India https://orcid.org/0000-0001-6656-0025
J.P. Anand DRDO-Defence Institute of Physiology and Allied Sciences (DIPAS), Timarpur, Delhi – 110 054, India https://orcid.org/0000-0002-0547-4438
Lalan Thakur DRDO-Defence Institute of Physiology and Allied Sciences (DIPAS), Timarpur, Delhi – 110 054, India https://orcid.org/0000-0003-4503-5218
D. Ravi DRDO-Defence Institute of Psychological Research (DIPR), Timarpur, Delhi – 110054, India https://orcid.org/0000-0002-7642-733X
A. Suresh DRDO-Defence Institute of Psychological Research (DIPR), Timarpur, Delhi – 110054, India https://orcid.org/0000-0002-3258-5440
Radhakrishna Kolpe DRDO-Defence Food Research Laboratory (DFRL), Mysore - 570 011, India https://orcid.org/0000-0001-7406-2667
Jayathilakan Kizhekkedath DRDO-Defence Food Research Laboratory (DFRL), Mysore - 570 011, India https://orcid.org/0000-0002-2670-9048
Bhuvnesh Kumar DRDO-Defence Institute of Physiology and Allied Sciences (DIPAS), Timarpur, Delhi – 110 054, India https://orcid.org/0000-0001-5466-306X
Usha Panjwani DRDO-Defence Institute of Physiology and Allied Sciences (DIPAS), Timarpur, Delhi – 110 054, India https://orcid.org/0000-0001-9255-8762

DOI: https://doi.org/10.14429/dlsj.6.15870

Keywords: Tyrosine, Norepinephrine, Selective attention, Sustained attention, Reaction time

Abstract

Supplementation of tyrosine, non-essential amino acid, and precursor of catecholamine was found to ameliorate the heat-induced alterations in latencies of event-related potential P300 and contingent negative variation. Here we present the effect of tyrosine supplementation on heat stress (exposure to ambient temperature 45 oC and relative humidity 30 %) induced alterations in behavior (attention, mood) and levels of plasma monoamines. Ten healthy male participants received a placebo food bar or tyrosine-containing food bar
(6.5 g in 50 g) 90 min before heat stress exposure of 90 min. Plasma and urine samples were assayed for catecholamine levels, their precursor, and metabolites using high-performance liquid chromatography. A computer-based automated test battery was used to assess attention and mood by profile of mood states questionnaire. A significantly higher plasma tyrosine (p<0.001) leading to an increased norepinephrine (p<0.05) levels in the tyrosine supplemented group was observed. Selective (p<0.001) and sustained attention (p<0.02) in the tyrosine group were significantly better compared to the placebo group. Reaction time and anger scores decreased (p<0.001) with tyrosine supplementation. It may be concluded that tyrosine supplementation improves heat stress-induced decrement in attention by maintaining the synthesis and turnover of norepinephrine.