Bilirubin, an old tetrapyrrolic compound that had occurred on Earth early on, is the final product of the catabolic heme pathway in the intravascular bed. Data from recent decades revealed its enormous bioactivity in a human body, including antioxidant, anti-inflammatory, immunosuppressive, antiproliferative, and even cell signaling activities that translate into beneficial effects of mildly elevated serum bilirubin concentrations resulting in prevention or amelioration of progression of many diseases of civilization. Furthermore, recent advances in bilirubin research have changed our understanding of bilirubin metabolism in the neonatal period, with discoveries of bilirubin reductase of bacterial origin in the intestinal lumen with direct pathophysiological and clinical implications. Similarly, our knowledge of the pathophysiology of neonatal jaundice phototherapy has improved substantially, although we are still at the beginning of the path to understand all the pathophysiological aspects and reveal related clinical implications. BULLET POINTS: Recent advances in our understanding of bilirubin metabolism with clear clinical implications, as well as other, so far putative, translational impacts. Demonstration of the beneficial biological potential of bilirubin, its evolutionary and ontogenetic functions, its possible role in chronobiology, and its correlation with increased fitness in elite athletes (a sort of gain of function). Discussion on the protective role of physiological neonatal jaundice. Inspiration for further basic and clinical research in specific fields of bilirubin metabolism.

• Publikační typ
• časopisecké články MeSH
• přehledy MeSH

BACKGROUND: Although bilirubin is a proven antioxidant substance and a protective factor against the development of various diseases, in emergency medicine, its increased concentration is considered solely a marker of organ damage and negative prognosis. However, clinical data on the role of bilirubin in cardiac arrest (CA) and reperfusion injury, are sparse. The presented study investigates the protective effects of increased serum bilirubin concentrations and genetic determinants (UGT1A1 promoter variations) on the outcomes of patients with refractory out-of-hospital CA (r-OHCA) in a randomized population. METHODS: Between March 1, 2013, and October 25, 2020, 256 randomized Prague OHCA patients with r-OHCA were evaluated for inclusion and categorized as having increased (>10 µmol/l) or low/normal serum bilirubin concentrations on hospital arrival and present or absent genetic variations for mild hyperbilirubinemia. The primary outcome was survival with a good neurological outcome (defined as cerebral performance category 1-2) 180 days after randomization. RESULTS: Finally, 164 patients were included in the bilirubin concentration analysis. Favorable neurological survival after 180 days occurred in 50 of 99 patients (50.5 %) in the group with higher initial serum bilirubin concentrations and 18 of 65 patients (27.7 %) in the low-bilirubin group (absolute difference 22.8 [8.1-37.5]; P = 0.006). The effect persisted also in multivariable analysis (OR for favorable outcome = 3.02 [95 % CI = 1.16-7.84]; P = 0.023). Genetic predisposition for mild hyperbilirubinemia was not associated with any patient outcomes. CONCLUSIONS: A higher initial serum bilirubin concentration predicts better outcomes in patients with refractory OHCA regardless of the treatment used. UGT1A1 gene promotor variations are not associated with refractory OHCA patient outcomes.

• Klíčová slova
• Antioxidants, Bilirubin, Cardiac arrest, Genetic variations, Mechanical circulatory support, Oxidative stress,
• Publikační typ
• časopisecké články MeSH

Bilirubin (BR) is a water-insoluble product of heme catabolism in mammals. Elevated blood concentrations of BR, especially in the neonatal period, are treated with blue-green light phototherapy. The major mechanism of BR elimination during phototherapy is photoisomerization, while a minor, less studied mechanism of degradation is oxidation. In this work, we studied the oxidation of the bilirubin model tetramethyl-dipyrrinone (Z-13) by singlet oxygen in methanol using UV-vis and ESI-MS spectroscopy, resulting in propentdyopents as the main oxidation products. We also identified two additional intermediates that were formed during the reaction (hydroperoxide 21a and imine 17). The structure of the hydroperoxide was confirmed by helium-tagging IR spectroscopy. Such reaction intermediates formed during the oxidation of BR or bilirubin models have not been described so far. We believe that this work can be used as a first step in studying the complex oxidation mechanism of BR during phototherapy.

• MeSH
• bilirubin * chemie   MeSH
• fotochemické procesy MeSH
• molekulární struktura MeSH
• oxidace-redukce MeSH
• singletový kyslík * chemie   MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• bilirubin * MeSH
• singletový kyslík * MeSH

• Publikační typ
• časopisecké články MeSH
• komentáře MeSH

Bilirubin is the principal product of heme catabolism. High concentrations of the pigment are neurotoxic, yet slightly elevated levels are beneficial. Being a potent antioxidant, oxidative transformations of bilirubin occur in vivo and lead to various oxidized fragments. The mechanisms of their formation, intrinsic biological activities, and potential roles in human pathophysiology are poorly understood. Degradation methods have been used to obtain samples of bilirubin oxidation products for research. Here, we report a complementary, fully synthetic method of preparation. Our strategy leverages repeating substitution patterns in the parent tetracyclic pigment. Functionalized ready-to-couple γ-lactone, γ-lactam, and pyrrole monocyclic building blocks were designed and efficiently synthesized. Subsequent modular combinations, supported by metal-catalyzed borylation and cross-coupling chemistries, translated into the concise assembly of the structurally diverse bilirubin oxidation products (BOXes, propentdyopents, and biopyrrins). The discovery of a new photoisomer of biopyrrin A named lumipyrrin is reported. Synthetic bilirubin oxidation products made available in sufficient purity and quantity will support future in vitro and in vivo investigations.

• MeSH
• bilirubin * metabolismus   MeSH
• lidé MeSH
• oxidace-redukce MeSH
• oxidační stres MeSH
• pyrroly * MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• bilirubin * MeSH
• pyrroly * MeSH

The crucial physiological process of heme breakdown yields biliverdin (BV) and bilirubin (BR) as byproducts. BV, BR, and the enzymes involved in their production (the "yellow players-YP") are increasingly documented as endogenous modulators of human health. Mildly elevated serum bilirubin concentration has been correlated with a reduced risk of multiple chronic pro-oxidant and pro-inflammatory diseases, especially in the elderly. BR and BV per se have been demonstrated to protect against neurodegenerative diseases, in which heme oxygenase (HMOX), the main enzyme in the production of pigments, is almost always altered. HMOX upregulation has been interpreted as a tentative defense against the ongoing pathologic mechanisms. With the demonstration that multiple cells possess YP, their propensity to be modulated, and their broad spectrum of activity on multiple signaling pathways, the YP have assumed the role of an adjustable system that can promote health in adults. Based on that, there is an ongoing effort to induce their activity as a therapeutic option, and natural compounds are an attractive alternative to the goal, possibly requiring only minimal changes in the life style. We review the most recent evidence of the potential of natural compounds in targeting the YP in the context of the most common pathologic condition of adult and elderly life.

• Klíčová slova
• Alzheimer’s disease, MAFLD, NRF2, Parkinson’s disease, bilirubin, cancer, heme-oxygenase, herbal medicine, neurodegeneration, nutraceuticals,
• MeSH
• bilirubin MeSH
• biliverdin MeSH
• dospělí MeSH
• hem MeSH
• hemová oxygenasa (decyklizující) MeSH
• játra MeSH
• lidé MeSH
• nemoci mozku * MeSH
• podpora zdraví * MeSH
• senioři MeSH
• Check Tag
• dospělí MeSH
• lidé MeSH
• senioři MeSH
• Publikační typ
• časopisecké články MeSH
• přehledy MeSH
• Názvy látek
• bilirubin MeSH
• biliverdin MeSH
• hem MeSH
• hemová oxygenasa (decyklizující) MeSH

Bilirubin has potent biological beneficial effects, protecting against atherosclerosis, obesity, and metabolic syndrome. The aim of this study was to assess serum bilirubin concentrations and (TA)n and (GT)n microsatellite variations in the promoter regions of the UGT1A1 and HMOX1 genes, respectively, in patients with type 2 diabetes mellitus (T2DM). The study was carried out in 220 patients with T2DM and 231 healthy control subjects, in whom standard biochemical tests were performed. The (TA)n and (GT)n dinucleotide variations were determined by means of fragment (size-based) analysis using an automated capillary DNA sequencer. Compared to controls, both male and female patients with T2DM had lower serum bilirubin concentrations (9.9 vs. 12.9 μmol/L, and 9.0 vs. 10.6 μmol/L, in men and women, respectively, p < 0.001). Phenotypic Gilbert syndrome was much less prevalent in T2DM patients, as was the frequency of the (TA)7/7UGT1A1 genotype in male T2DM patients. (GT)nHMOX1 genetic variations did not differ between diabetic patients and controls. Our results demonstrate that the manifestation of T2DM is associated with lower serum bilirubin concentrations. Consumption of bilirubin due to increased oxidative stress associated with T2DM seems to be the main explanation, although (TA)n repeat variations in UGT1A1 partially contribute to this phenomenon.

• Klíčová slova
• Gilbert syndrome, HMOX1, UGT1A1, benign hyperbilirubinemia, bilirubin, heme oxygenase, type 2 diabetes mellitus,
• MeSH
• bilirubin metabolismus   MeSH
• diabetes mellitus 2. typu * genetika   MeSH
• genotyp MeSH
• glukuronosyltransferasa genetika   metabolismus   MeSH
• hemoxygenasa-1 genetika   metabolismus   MeSH
• lidé MeSH
• polymorfismus genetický * MeSH
• promotorové oblasti (genetika) MeSH
• Check Tag
• lidé MeSH
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• Geografické názvy
• Česká republika epidemiologie   MeSH
• Názvy látek
• bilirubin MeSH
• glukuronosyltransferasa MeSH
• hemoxygenasa-1 MeSH
• HMOX1 protein, human MeSH Prohlížeč

Bilirubin has several physiological functions, both beneficial and harmful. In addition to reactive oxygen species-scavenging activities, bilirubin has potent immunosuppressive effects associated with long-term pathophysiological sequelae. It has been recently recognized as a hormone with endocrine actions and interconnected effects on various cellular signaling pathways. Current studies show that bilirubin also decreases adiposity and prevents metabolic and cardiovascular diseases. All in all, the physiological importance of bilirubin is only now coming to light, and strategies for increasing plasma bilirubin levels to combat chronic diseases are starting to be considered. This review discusses the beneficial effects of increasing plasma bilirubin, incorporates emerging areas of bilirubin biology, and provides key concepts to advance the field.

• Klíčová slova
• BVRA, Blvra, HO-1, Hmox1, bilirubin, cardiovascular disease, cell signaling, heme oxygenase, metabolism, nuclear receptors,
• MeSH
• bilirubin * metabolismus   farmakologie   MeSH
• hemoxygenasa-1 metabolismus   MeSH
• kardiovaskulární nemoci * MeSH
• lidé MeSH
• reaktivní formy kyslíku metabolismus   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• přehledy MeSH
• Research Support, N.I.H., Extramural MeSH
• Názvy látek
• bilirubin * MeSH
• hemoxygenasa-1 MeSH
• reaktivní formy kyslíku MeSH

Oxidative stress and inflammation contribute significantly to atherogenesis. We and others have demonstrated that mildly elevated serum bilirubin levels protect against coronary and peripheral atherosclerosis, most likely due to the antioxidant and anti-inflammatory activities of bilirubin. The aim of the present study was to assess serum bilirubin and the markers of oxidative stress and inflammation in both healthy subjects and patients with various forms of atherosclerosis. The study was performed in patients with premature myocardial infarction (n = 129), chronic ischemic heart disease (n = 43), peripheral artery disease (PAD, n = 69), and healthy subjects (n = 225). In all subjects, standard serum biochemistry, UGT1A1 genotypes, total antioxidant status (TAS), and concentrations of various pro- and anti-inflammatory chemokines were determined. Compared to controls, all atherosclerotic groups had significantly lower serum bilirubin and TAS, while having much higher serum high-sensitivity C-reactive protein (hsCRP) and most of the analyzed proinflammatory cytokines (p < 0.05 for all comparisons). Surprisingly, the highest inflammation, and the lowest antioxidant status, together with the lowest serum bilirubin, was observed in PAD patients, and not in premature atherosclerosis. In conclusion, elevated serum bilirubin is positively correlated with TAS, and negatively related to inflammatory markers. Compared to healthy subjects, patients with atherosclerosis have a much higher degree of oxidative stress and inflammation.

• Klíčová slova
• atherogenesis, atherosclerosis, bilirubin, inflammation, oxidative stress,
• Publikační typ
• časopisecké články MeSH

OBJECTIVES: Bilirubin is a potent endogenous antioxidant and immunomodulating substance, which is also implicated in both cell signalling and various metabolic pathways. Mild elevation of systemic bilirubin concentrations provides substantial protection against many diseases of civilization. Rare published reports have suggested that serum bilirubin might also be relevant to sports performance. The purpose of the current study was to evaluate serum bilirubin concentrations and the prevalence of Gilbert syndrome (GS) in elite athletes. METHODS: The study was carried out in 536 consecutive healthy elite athletes and in 2594 individuals of the Czech post-MONICA study representing the general Czech population. Serum bilirubin concentrations, the prevalence of benign hyperbilirubinemia > 17 µmol/L (1 mg/dL, a phenotypic sign of GS), and a variant of the UGT1A1 gene promoter responsible for GS manifestation in Caucasians (rs81753472) were evaluated in study subjects. RESULTS: Compared to the general Czech population, significantly higher serum bilirubin concentrations were found in elite athletes (9.6 vs. 11.6 µmol/L, p < 0.001), both in men (11.3 vs. 12.6 µmol/L, p < 0.001) and women (8.3 vs. 10.5 µmol/L, p < 0.001). Furthermore, the prevalence of GS was also significantly higher in elite athletes (9.6 vs. 22%, p < 0.001) together with the tendency to higher frequencies of the genotypes (TA)7/7 and (TA)6/7 UGT1A1. CONCLUSION: Elite athletes have significantly higher concentrations of serum bilirubin, the most potent endogenous antioxidant substance known. Simultaneously, the prevalence of GS syndrome is also much higher in elite athletes, suggesting that a mild elevation of serum bilirubin might predispose to better sports performance.

• Klíčová slova
• Bilirubin, Elite athletes, Gene predisposition, Gilbert syndrome, Sports performance, UGT1A1 gene promoter,
• Publikační typ
• časopisecké články MeSH