Can supplementation of tryptophan in parenteral nutrition increase melatonin and alleviate inflammatory response?

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Yaşar N. F., Badak B., Salış M., Kar F., Öner K. S.

REVISTA DA ASSOCIACAO MEDICA BRASILEIRA, vol.70, no.3, pp.28-31, 2024 (SCI-Expanded)

  • Publication Type: Article / Article
  • Volume: 70 Issue: 3
  • Publication Date: 2024
  • Doi Number: 10.1590/1806-9282.20230826
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus, CAB Abstracts, MEDLINE, Veterinary Science Database
  • Page Numbers: pp.28-31
  • Kütahya Health Sciences University Affiliated: Yes


OBJECTIVE: Endogenous melatonin is produced from tryptophan which is an essential amino acid. Besides its role in the regulation of sleep patterns,

melatonin has anti-inflammatory effects. In this case-control study, we aimed to compare tryptophan and melatonin levels and their relationship with

the inflammatory response, specifically serum interleukin-1, interleukin-6, and c-reactive protein levels following major abdominal surgery in patients

with food restriction and who receive parenteral nutritional therapy.

METHODS: We enrolled 40 patients between the ages of 18 and 65 years in the study. We collected blood and urine samples 48 h before the

operation and on postoperative days 1, 3, and 5.

RESULTS AND CONCLUSION: The tryptophan levels in the experimental group were higher than in the control group but failed to reach any statistical

difference. Melatonin levels were increased in both groups following the surgery compared with preoperative levels. The increase in the experimental

group was statistically different 3 days after the surgery. The difference in the level of interleukin-1 between the control and the experimental groups

was greatest on postoperative day 3. On postoperative day 3, the interleukin-6 level in the treatment group was slightly higher than in the control

group. We did not find any difference in the levels of c-reactive protein between the groups. As a result, the levels of tryptophan and melatonin were

increased in the parenteral nutrition group, irrespective of the postoperative inflammatory response.

KEYWORDS: Melatonin. Tryptophan. Inflammatory response. Surgery. Nutrition. Parenteral nutrition.