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Nawaz H, Aslam M, Rehman T. Neonatal hyperbilirubinemia: Background and recent literature updates on the diagnosis and treatment. Physiol Int 2021; 108:151-171. [PMID: 34166220 DOI: 10.1556/2060.2021.00018] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2021] [Accepted: 04/26/2021] [Indexed: 11/19/2022]
Abstract
Hyperbilirubinemia or jaundice has been studied by many researchers because of its diverse causes and potential for toxicity especially in the neonate but to a lesser extent beyond the neonate as well. Several studies have been performed on the normal metabolism and metabolic disorders of bilirubin in last decades of the 20th century. The recent advancement in research and technology facilitated for the researchers to investigate new horizons of the causes and treatment of neonatal hyperbilirubinemia. This review gives a brief introduction to hyperbilirubinemia and jaundice and the recent advancement in the treatment of neonatal hyperbilirubinemia. It reports modifications in the previously used methods and findings of some newly developed ones. At present, ample literature is available discussing the issues regarding hyperbilirubinemia and jaundice, but still more research needs to be done.
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Affiliation(s)
- H Nawaz
- 1Department of Biochemistry, Bahauddin Zakariya University, 60800, Multan, Pakistan
| | - M Aslam
- 1Department of Biochemistry, Bahauddin Zakariya University, 60800, Multan, Pakistan
| | - T Rehman
- 2Department of Chemistry, The Women University Multan, 60000, Multan, Pakistan
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Ma G, Zhang Y, Chen W, Tang Z, Xin X, Yang P, Liu X, Cai W, Hu M. Inhibition of Human UGT1A1-Mediated Bilirubin Glucuronidation by Polyphenolic Acids Impact Safety of Popular Salvianolic Acid A/B-Containing Drugs and Herbal Products. Mol Pharm 2017; 14:2952-2966. [PMID: 28603997 DOI: 10.1021/acs.molpharmaceut.7b00365] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Bilirubin-related adverse reactions (ADR, e.g., jaundice and hyperbilirubinemia) induced by herbs rich in certain polyphenolic acids are widely reported. However, the causes and the mechanisms underlying these ADR are not well understood. The purpose of this article is to determine the mechanism by which certain polyphenolic acids inhibit UGT1A1-mediated bilirubin glucuronidation, leading to jaundice or hyperbilirubinemia. We investigated in vitro inhibitory effects on bilirubin glucuronidation of salvianolic acid A (SAA), salvianolic acid B (SAB), danshensu (DSS), protocatechuic aldehyde (PA), and rosmarinic acid (RA), as well as two Salvia miltiorrhiza injections (DSI and CDI) rich in polyphenolic acids. The results showed that average formation rates of three bilirubin glucuronides displayed a significant difference (p < 0.05) and the formation of monoglucuronide was favored regardless if an inhibitor was present or not. SAA, SAB, DSI, and CDI, but not DSS, PA, and RA, significantly inhibited human UGT1A1-mediated bilirubin glucuronidation via a mixed-type inhibitory mechanism. Average IC50 values of SAA, SAB, DSI, and CDI-mediated inhibition of bilirubin glucuronidation were bilirubin concentration-dependent, and their values (against total bilirubin glucuronidation) were in the range 0.44 ± 0.02 to 0.86 ± 0.04 μg/mL (for SAA), 4.22 ± 0.30 to 12.50 ± 0.93 μg/mL (for SAB), 9.29 ± 0.76 to 18.82 ± 0.63 μg/mL (for DSI), and 9.18 ± 2.00 to 22.36 ± 1.39 μg/mL (for CDI), respectively. In conclusion, SAA and its analog SAB are the main ingredients responsible for inhibition of bilirubin glucuronidation by DSI and CDI, whose use is associated with many high bilirubin-related ADR.
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Affiliation(s)
- Guo Ma
- Department of Clinical Pharmacy, School of Pharmacy, Fudan University , 826 Zhangheng Road, Shanghai 201203, P.R. China
| | - Ying Zhang
- Department of Clinical Pharmacy, School of Pharmacy, Fudan University , 826 Zhangheng Road, Shanghai 201203, P.R. China
| | - Wenyan Chen
- Department of Clinical Pharmacy, School of Pharmacy, Fudan University , 826 Zhangheng Road, Shanghai 201203, P.R. China
| | - Zhifang Tang
- Department of Clinical Pharmacy, School of Pharmacy, Fudan University , 826 Zhangheng Road, Shanghai 201203, P.R. China
| | - Xiaoming Xin
- Department of Clinical Pharmacy, School of Pharmacy, Fudan University , 826 Zhangheng Road, Shanghai 201203, P.R. China
| | - Ping Yang
- Department of Clinical Pharmacy, School of Pharmacy, Fudan University , 826 Zhangheng Road, Shanghai 201203, P.R. China
| | - Xiaoqin Liu
- Department of Clinical Pharmacy, School of Pharmacy, Fudan University , 826 Zhangheng Road, Shanghai 201203, P.R. China
| | - Weimin Cai
- Department of Clinical Pharmacy, School of Pharmacy, Fudan University , 826 Zhangheng Road, Shanghai 201203, P.R. China
| | - Ming Hu
- Department of Pharmacological and Pharmaceutical Sciences, College of Pharmacy, University of Houston , 1441 Moursund Street, Houston, Texas 77030, United States
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Simultaneous determination of bilirubin and its glucuronides in liver microsomes and recombinant UGT1A1 enzyme incubation systems by HPLC method and its application to bilirubin glucuronidation studies. J Pharm Biomed Anal 2014; 92:149-59. [DOI: 10.1016/j.jpba.2014.01.025] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2013] [Revised: 01/17/2014] [Accepted: 01/18/2014] [Indexed: 12/22/2022]
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Zhou J, Tracy TS, Remmel RP. Bilirubin glucuronidation revisited: proper assay conditions to estimate enzyme kinetics with recombinant UGT1A1. Drug Metab Dispos 2010; 38:1907-11. [PMID: 20668247 DOI: 10.1124/dmd.110.033829] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Bilirubin, an end product of heme catabolism, is primarily eliminated via glucuronic acid conjugation by UGT1A1. Impaired bilirubin conjugation, caused by inhibition of UGT1A1, can result in clinical consequences, including jaundice and kernicterus. Thus, evaluation of the ability of new drug candidates to inhibit UGT1A1-catalyzed bilirubin glucuronidation in vitro has become common practice. However, the instability of bilirubin and its glucuronides presents substantial technical challenges to conduct in vitro bilirubin glucuronidation assays. Furthermore, because bilirubin can be diglucuronidated through a sequential reaction, establishment of initial rate conditions can be problematic. To address these issues, a robust high-performance liquid chromatography assay to measure both bilirubin mono- and diglucuronide conjugates was developed, and the incubation conditions for bilirubin glucuronidation by human embryonic kidney 293-expressed UGT1A1 were carefully characterized. Our results indicated that bilirubin glucuronidation should be assessed at very low protein concentrations (0.05 mg/ml protein) and over a short incubation time (5 min) to assure initial rate conditions. Under these conditions, bilirubin total glucuronide formation exhibited a hyperbolic (Michaelis-Menten) kinetic profile with a K(m) of ∼0.2 μM. In addition, under these initial rate conditions, the relative proportions between the total monoglucuronide and the diglucuronide product were constant across the range of bilirubin concentration evaluated (0.05-2 μM), with the monoglucuronide being the predominant species (∼70%). In conclusion, establishment of appropriate incubation conditions (i.e., very low protein concentrations and short incubation times) is necessary to properly characterize the kinetics of bilirubin glucuronidation in a recombinant UGT1A1 system.
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Affiliation(s)
- Jin Zhou
- College of Pharmacy, University of Minnesota, 308 Harvard St SE, Minneapolis, MN 55455, USA
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Heirwegh KP, Fevery J, Blanckaert N. Chromatographic analysis and structure determination of biliverdins and bilirubins. JOURNAL OF CHROMATOGRAPHY 1989; 496:1-26. [PMID: 2687309 DOI: 10.1016/s0378-4347(00)82549-9] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Recent applications of thin-layer chromatographic (TLC) and high-performance liquid chromatographic (HPLC) procedures has revealed an unexpected wide variety of naturally occurring unconjugated and conjugated bilirubins. Biliverdins seems to occur only in unconjugated forms, mainly as the IX alpha isomer. Several synthetic biliverdins and bilirubins present interesting models for biochemical and metabolic studies. Owing to recent recognition of the astounding heterogeneity of natural bilirubins and to the various artifactual changes that bile pigments can undergo, considerable confusion has existed, and still exists, with regard to the nomenclature of the bile pigments and their derivatives. To set a background for further discussion, the present review starts with a brief discussion of nomenclature and of the various characteristic forms of lability of the bile pigments. TLC and HPLC procedures for preparation and analysis of unconjugated biliverdins and bilirubins and their methyl ester and sugar ester conjugates, as well as procedures for analysis of bilirubin-protein conjugates, are then discussed. Since, in view of the lability and pronounced heterogeneity of bile pigments, it is important to assess the composition and nature of chromatographically isolated pigments, the review is concluded by a brief evaluation of various structural tests.
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Affiliation(s)
- K P Heirwegh
- Department of Medical Research, Katholieke Universiteit Leuven, Campus Gasthuisberg, Belgium
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Sieg A, Stiehl A, Heirwegh KP, Fevery J, Raedsch R, Kommerell B. Similarities in maximal biliary bilirubin output in the normal rat after administration of unconjugated bilirubin or bilirubin diglucuronide. Hepatology 1989; 10:14-20. [PMID: 2737598 DOI: 10.1002/hep.1840100104] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
The rate-limiting step in the overall plasma-to-bile transport of a saturating load of bilirubin is still a matter of controversy. We reassessed the apparent maximal biliary bilirubin excretion following i.v. infusion of unconjugated bilirubin and--for the first time--of highly purified bilirubin diglucuronide in the rat. The bilirubin diglucuronide preparation could be kept in a stable form at -20 degrees C for at least 2 months after addition of 3 mM sodium ascorbate. The biliary bilirubin excretion rates in animals with and without bile depletion in order to induce different flow rates were comparable after infusion of unconjugated bilirubin and of bilirubin diglucuronide. No significant hydrolysis of bilirubin diglucuronide seemed to occur during the hepatic transport of the pigment. Injection of bilirubin diglucuronide into rats which were already being infused with saturating doses of unconjugated bilirubin did not result in increased biliary bilirubin excretion. In contrast, a reversible inhibition of bilirubin output and bile acid-dependent bile flow was observed. If unconjugated and diglucuronidated bilirubin follow the same intracellular routes, the present results would suggest that conjugation did not restrict maximal biliary excretion. However, if exogenously administered diglucuronide utilizes a separate pathway, as was recently proposed, the biliary secretion of this exogenous conjugate might be restricted, presumably due to a toxic effect of the high local concentration of diglucuronide. The pathways utilized by the unconjugated pigment, on the other hand, could be primarily determined by the conjugating capacity.
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Affiliation(s)
- A Sieg
- Department of Medicine, University of Heidelberg, Federal Republic of Germany
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