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.

• Keywords
• Antioxidants, Bilirubin, Cardiac arrest, Genetic variations, Mechanical circulatory support, Oxidative stress,
• Publication type
• Journal Article 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.

• Keywords
• Alzheimer’s disease, MAFLD, NRF2, Parkinson’s disease, bilirubin, cancer, heme-oxygenase, herbal medicine, neurodegeneration, nutraceuticals,
• MeSH
• Bilirubin MeSH
• Biliverdine MeSH
• Adult MeSH
• Heme MeSH
• Heme Oxygenase (Decyclizing) MeSH
• Liver MeSH
• Humans MeSH
• Brain Diseases * MeSH
• Health Promotion * MeSH
• Aged MeSH
• Check Tag
• Adult MeSH
• Humans MeSH
• Aged MeSH
• Publication type
• Journal Article MeSH
• Review MeSH
• Names of Substances
• Bilirubin MeSH
• Biliverdine MeSH
• Heme MeSH
• Heme Oxygenase (Decyclizing) 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.

• Keywords
• Gilbert syndrome, HMOX1, UGT1A1, benign hyperbilirubinemia, bilirubin, heme oxygenase, type 2 diabetes mellitus,
• MeSH
• Bilirubin metabolism   MeSH
• Diabetes Mellitus, Type 2 * genetics   MeSH
• Genotype MeSH
• Glucuronosyltransferase genetics   metabolism   MeSH
• Heme Oxygenase-1 genetics   metabolism   MeSH
• Humans MeSH
• Polymorphism, Genetic * MeSH
• Promoter Regions, Genetic MeSH
• Check Tag
• Humans MeSH
• Male MeSH
• Female MeSH
• Publication type
• Journal Article MeSH
• Geographicals
• Czech Republic epidemiology   MeSH
• Names of Substances
• Bilirubin MeSH
• Glucuronosyltransferase MeSH
• Heme Oxygenase-1 MeSH
• HMOX1 protein, human MeSH Browser

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.

• Keywords
• BVRA, Blvra, HO-1, Hmox1, bilirubin, cardiovascular disease, cell signaling, heme oxygenase, metabolism, nuclear receptors,
• MeSH
• Bilirubin * metabolism   pharmacology   MeSH
• Heme Oxygenase-1 metabolism   MeSH
• Cardiovascular Diseases * MeSH
• Humans MeSH
• Reactive Oxygen Species metabolism   MeSH
• Check Tag
• Humans MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Review MeSH
• Research Support, N.I.H., Extramural MeSH
• Names of Substances
• Bilirubin * MeSH
• Heme Oxygenase-1 MeSH
• Reactive Oxygen Species 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.

• Keywords
• atherogenesis, atherosclerosis, bilirubin, inflammation, oxidative stress,
• Publication type
• Journal Article 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.

• Keywords
• Bilirubin, Elite athletes, Gene predisposition, Gilbert syndrome, Sports performance, UGT1A1 gene promoter,
• Publication type
• Journal Article MeSH

There are concerns about altered vascular functions that could play an important role in the pathogenesis and influence the severity of chronic disease, however, increased cardiovascular risk in paediatric cystic fibrosis (CF) has not been yet fully understood. Aim was to analyse vascular disease risk and investigate changes over times in CF and controls. We prospectively enrolled 22 CF subjects (a median age of 16.07 years), and 22 healthy demographically matched controls (a median age of 17.28 years) and determined endothelial function. We utilised a combined diagnostic approach by measuring the plethysmographic Reactive Hyperemia Index (RHI) as the post-to preocclusive endothelium-dependent changes of vascular tone, and biomarkers that are known to be related to endothelial dysfunction (ED): asymmetric dimethyl arginine (ADMA), high-sensitive CRP (hsCRP), VCAM-1 and E-selectin. RHI values were significantly lower in CF young adults (p<0.005). HsCRP (p<0.005), E-selectin (p<0.001) and VCAM-1 (p<0.001) were significantly increased in CF patients since childhood. The findings have provided a detailed account of the ongoing process of microvascular dysfunction with gradual progression with the age of CF patients, making them further at risk of advanced vascular disease. Elevations of biomarkers in CF children with not yet demonstrated RHI changes but with significantly reduced RHI in adulthood and lipid profile changes indicate the possible occurrence of ED with CF-related specific risk factors over time and will enable us to provide the best possible support.

• MeSH
• Biomarkers blood   MeSH
• Endothelium, Vascular physiopathology   MeSH
• Cystic Fibrosis blood   diagnosis   physiopathology   MeSH
• Child MeSH
• Adult MeSH
• Hyperemia * MeSH
• Humans MeSH
• Adolescent MeSH
• Young Adult MeSH
• Disease Progression MeSH
• Prospective Studies MeSH
• Case-Control Studies MeSH
• Age Factors MeSH
• Check Tag
• Child MeSH
• Adult MeSH
• Humans MeSH
• Adolescent MeSH
• Young Adult MeSH
• Male MeSH
• Female MeSH
• Publication type
• Journal Article MeSH
• Observational Study MeSH
• Names of Substances
• Biomarkers MeSH

Bilirubin is considered to be one of the most potent endogenous antioxidants in humans. Its serum concentrations are predominantly affected by the activity of hepatic bilirubin UDP-glucuronosyl transferase (UGT1A1). Our objective was to analyze the potential bilirubin-modulating effects of natural polyphenols from milk thistle (Silybum marianum), a hepatoprotective herb. Human hepatoblastoma HepG2 cells were exposed to major polyphenolic compounds isolated from milk thistle. Based on in vitro studies, 2,3-dehydrosilybins A and B were selected as the most efficient compounds and applied either intraperitoneally or orally for seven days to C57BL/6 mice. After, UGT1A1 mRNA expression, serum, intrahepatic bilirubin concentrations, and lipoperoxidation in the liver tissue were analyzed. All natural polyphenols used increased intracellular concentration of bilirubin in HepG2 cells to a similar extent as atazanavir, a known bilirubinemia-enhancing agent. Intraperitoneal application of 2,3-dehydrosilybins A and B (the most efficient flavonoids from in vitro studies) to mice (50 mg/kg) led to a significant downregulation of UGT1A1 mRNA expression (46 ± 3% of controls, p < 0.005) in the liver and also to a significant increase of the intracellular bilirubin concentration (0.98 ± 0.03vs.1.21 ± 0.02 nmol/mg, p < 0.05). Simultaneously, a significant decrease of lipoperoxidation (61 ± 2% of controls, p < 0.005) was detected in the liver tissue of treated animals, and similar results were also observed after oral treatment. Importantly, both application routes also led to a significant elevation of serum bilirubin concentrations (125 ± 3% and 160 ± 22% of the controls after intraperitoneal and oral administration, respectively, p < 0.005 in both cases). In conclusion, polyphenolic compounds contained in silymarin, in particular 2,3-dehydrosilybins A and B, affect hepatic and serum bilirubin concentrations, as well as lipoperoxidation in the liver. This phenomenon might contribute to the hepatoprotective effects of silymarin.

• MeSH
• Bilirubin metabolism   MeSH
• Hep G2 Cells MeSH
• Flavonoids chemistry   isolation & purification   pharmacology   MeSH
• Glucuronosyltransferase genetics   metabolism   MeSH
• Heme Oxygenase-1 genetics   metabolism   MeSH
• Intracellular Space metabolism   MeSH
• Liver drug effects   metabolism   MeSH
• Humans MeSH
• RNA, Messenger genetics   metabolism   MeSH
• Mice, Inbred C57BL MeSH
• Lipid Peroxidation drug effects   MeSH
• Gene Expression Regulation, Enzymologic drug effects   MeSH
• Silybin administration & dosage   pharmacology   MeSH
• Silymarin isolation & purification   pharmacology   MeSH
• Animals MeSH
• Check Tag
• Humans MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH
• Names of Substances
• Bilirubin MeSH
• Flavonoids MeSH
• Glucuronosyltransferase MeSH
• Heme Oxygenase-1 MeSH
• HMOX1 protein, human MeSH Browser
• RNA, Messenger MeSH
• Silybin MeSH
• Silymarin MeSH
• UGT1A1 enzyme MeSH Browser