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Example:10.1021/acsami.1c06204 or Chem. Rev., 2007, 107, 2411-2502
5-Methoxytryptophan attenuates postinfarct cardiac injury by controlling oxidative stress and immune activation
Journal of Molecular and Cellular Cardiology  (IF5),  Pub Date : 2021-06-01, DOI: 10.1016/j.yjmcc.2021.05.014
Wan-Tseng Hsu, Ya-Hsuan Tseng, Hsiang-Yiang Jui, Chen-Chin Kuo, Kenneth K. Wu, Chii-Ming Lee

Aims

Myocardial infarction (MI) remains a major cause of heart failure. 5-Methoxytryptophan (5-MTP), a 5-methoxyindole metabolite of L-tryptophan, exerts anti-inflammatory and antifibrotic effects, but MI impairs the biosynthesis of cardiac 5-MTP. Therefore, we evaluated the effect of exogenous 5-MTP administration on rescuing post-MI cardiac injury.

Methods and results

After a detailed pharmacokinetic analysis of 5-MTP, Sprague Dawley rats that had undergone left anterior descending coronary artery ligation received intraperitoneal administration of either 17 mg/kg 5-MTP or saline at 0.5 and 24 h after MI. Cardiac systolic function, infarction size, and fibrosis were evaluated using echocardiography, triphenyltetrazolium chloride staining, and Masson trichrome staining, respectively. Myocardial apoptosis was analyzed by staining for caspase-3 and cardiac troponin I. 5-MTP treatment decreased the infarct area and myocardial apoptosis; attenuated systolic dysfunction and left ventricular dilatation; and reduced cardiomyocyte hypertrophy, myocardial fibrosis, and infarct expansion. Crucially, 5-MTP alleviated oxidative stress by preserving mitochondrial antioxidant enzymes and downregulating reactive oxygen species–generating NADPH oxidase isoforms and endothelin-1. Consequently, 5-MTP-treated MI rat hearts exhibited lower levels of chemokines and cytokines, namely interleukin (IL)-1β, IL-18, IL-6, C-C motif chemokine ligand (CCL)-2, and CCL5, accompanied by reduced infiltration of CD11b+ cells and CD4+ T cells. Notably, 5-MTP protected against H2O2-induced damage in HL-1 cardiomyocytes and human umbilical vein endothelial cells in vitro.

Conclusion

5-MTP prevented post-MI cardiac injury by promoting mitochondrial stabilization and controlling redox imbalance. This cytoprotective effect ameliorated macrophage and T-cell infiltration, thus reducing the infarct size, attenuating fibrosis, and restoring myocardial function.