1
|
Murbach TS, Glávits R, Endres JR, Hirka G, Vértesi A, Béres E, Szakonyiné IP. A toxicological evaluation of lithium orotate. Regul Toxicol Pharmacol 2021; 124:104973. [PMID: 34146638 DOI: 10.1016/j.yrtph.2021.104973] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2021] [Accepted: 06/11/2021] [Indexed: 11/27/2022]
Abstract
Lithium orotate, the salt of lithium and orotic acid, has been marketed for decades as a supplemental source of lithium with few recorded adverse events. Nonetheless, there have been some concerns in the scientific literature regarding orotic acid, and pharmaceutical lithium salts are known to have a narrow therapeutic window, albeit, at lithium equivalent therapeutic doses 5.5-67 times greater than typically recommended for supplemental lithium orotate. To our knowledge, the potential toxicity of lithium orotate has not been investigated in preclinical studies; thus, we conducted a battery of genetic toxicity tests and an oral repeated-dose toxicity test in order to further explore its safety. Lithium orotate was not mutagenic or clastogenic in bacterial reverse mutation and in vitro mammalian chromosomal aberration tests, respectively, and did not exhibit in vivo genotoxicity in a micronucleus test in mice. In a 28-day, repeated-dose oral toxicity study, rats were administered 0, 100, 200, or 400 mg/kg body weight/day of lithium orotate by gavage. No toxicity or target organs were identified; therefore, a no observed adverse effect level was determined as 400 mg/kg body weight/day. These results are supportive of the lack of a postmarket safety signal from several decades of human consumption.
Collapse
Affiliation(s)
- Timothy S Murbach
- AIBMR Life Sciences, Inc., 1425 Broadway, Suite 458, Seattle, WA, 98122, USA.
| | - Róbert Glávits
- Toxi-Coop Zrt., Berlini utca 47-49, H-1045, Budapest, Hungary.
| | - John R Endres
- AIBMR Life Sciences, Inc., 1425 Broadway, Suite 458, Seattle, WA, 98122, USA.
| | - Gábor Hirka
- Toxi-Coop Zrt., Berlini utca 47-49, H-1045, Budapest, Hungary; Toxi-Coop Zrt., Arácsi út 97, 8230, Balatonfüred, Hungary.
| | - Adél Vértesi
- Toxi-Coop Zrt., Arácsi út 97, 8230, Balatonfüred, Hungary.
| | - Erzsébet Béres
- Toxi-Coop Zrt., Arácsi út 97, 8230, Balatonfüred, Hungary.
| | | |
Collapse
|
2
|
Löffler M, Carrey EA, Zameitat E. Orotate (orotic acid): An essential and versatile molecule. NUCLEOSIDES NUCLEOTIDES & NUCLEIC ACIDS 2017; 35:566-577. [PMID: 27906623 DOI: 10.1080/15257770.2016.1147580] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Orotate (OA) is well-known as a precursor in biosynthesis of pyrimidines; in mammals it is released from the mitochondrial dihydroorotate dehydrogenase (DHODH) for conversion to UMP by the cytoplasmic UMP synthase enzyme. OA is also a normal part of the diet, being found in milk and dairy products, and it is converted to uridine for use in the pyrimidine salvage pathway predominantly in liver, kidney and erythrocytes. Early research into nutrition identified orotate as "vitamin B13," and its use as a complex with organic cations or metal ions was promulgated in body-building, and in assisting therapies of metabolic syndromes. It has recently been established that the amelioration of gout by dairy products arises from the competition of orotate and urate at the hURAT1 transporter. The orotic aciduria that arises in children with defective UMP synthase can be rescued by oral uridine therapy, since UMP is the end-product and also a feedback inhibitor of the de novo pathway. In contrast, Miller (dysmorphology) syndrome is connected with defects in DHODH, and hence in the supply of OA, and cannot be helped by uridine. Other models of dysmorphisms are connected with enzymes early in the pyrimidine de novo pathway. We conclude that the OA molecule is itself required for the regulation of genes that are important in the development of cells, tissues and organisms.
Collapse
Affiliation(s)
- M Löffler
- a Institute of Physiological Chemistry, Faculty of Medicine, Philipps University Marburg , Marburg , Germany
| | - E A Carrey
- b Institute of Child Health, University College London , GB
| | | |
Collapse
|
3
|
Gümüş Yılmaz G, Destanoğlu O. Simultaneous Determination of Different Anions in Milk Samples Using Ion Chromatography with Conductivity Detection. JOURNAL OF THE TURKISH CHEMICAL SOCIETY, SECTION A: CHEMISTRY 2016. [DOI: 10.18596/jotcsa.287340] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
|
4
|
Orotic Acid, More Than Just an Intermediate of Pyrimidine de novo Synthesis. J Genet Genomics 2015; 42:207-19. [DOI: 10.1016/j.jgg.2015.04.001] [Citation(s) in RCA: 49] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2014] [Revised: 04/04/2015] [Accepted: 04/09/2015] [Indexed: 01/21/2023]
|
5
|
Dong Z, Liu Y, Zhang JT. Regulation of ribonucleotide reductase M2 expression by the upstream AUGs. Nucleic Acids Res 2005; 33:2715-25. [PMID: 15888728 PMCID: PMC1097769 DOI: 10.1093/nar/gki569] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022] Open
Abstract
Ribonucleotide reductase catalyzes a rate-limiting reaction in DNA synthesis by converting ribonucleotides to deoxyribonucleotides. It consists of two subunits and the small one, M2 (or R2), plays an essential role in regulating the enzyme activity and its expression is finely controlled. Changes in the M2 level influence the dNTP pool and, thus, DNA synthesis and cell proliferation. M2 gene has two promoters which produce two major mRNAs with 5′-untranslated regions (5′-UTRs) of different lengths. In this study, we found that the M2 mRNAs with the short (63 nt) 5′-UTR can be translated with high efficiency whereas the mRNAs with the long (222 nt) one cannot. Examination of the long 5′-UTR revealed four upstream AUGs, which are in the same reading frame as the unique physiological translation initiation codon. Further analysis demonstrated that these upstream AUGs act as negative cis elements for initiation at the downstream translation initiation codon and their inhibitory effect on M2 translation is eIF4G dependent. Based on the findings of this study, we conclude that the expression of M2 is likely regulated by fine tuning the translation from the mRNA with a long 5′-UTR during viral infection and during the DNA replication phase of cell proliferation.
Collapse
Affiliation(s)
| | | | - Jian-Ting Zhang
- To whom correspondence should be addressed. Tel: +1 317 278 4503; Fax: +1 317 274 8046;
| |
Collapse
|
6
|
Dong Z, Liu LH, Han B, Pincheira R, Zhang JT. Role of eIF3 p170 in controlling synthesis of ribonucleotide reductase M2 and cell growth. Oncogene 2004; 23:3790-801. [PMID: 15094776 DOI: 10.1038/sj.onc.1207465] [Citation(s) in RCA: 90] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
Translation initiation in eukaryotes is a rate-limiting step in protein synthesis. It is a complicated process that involves many eukaryotic initiation factors (eIFs). Altering the expression level or the function of eIFs may influence the synthesis of some proteins and consequently cause abnormal cell growth and malignant transformation. P170, the largest putative subunit of eIF3, has been found elevated in human breast, cervical, esophageal, and lung cancers, suggesting that p170 may have a potential role in malignant transformation and/or cell growth control. Our recent studies suggested that p170 is likely a translational regulator and it may mediate the effect of mimosine on the translation of a subset mRNAs. Mimosine, a plant nonprotein amino acid, inhibits mammalian DNA synthesis, an essential event of cell growth. The rate-limiting step in DNA synthesis is the conversion of the ribonucleotides to their corresponding deoxyribonucleotides catalysed by ribonucleotide reductase of which the activity is regulated by the level of its M2 subunit. It has been reported that inhibiting the activity of M2 also inhibits cell growth. To understand the relationship between protein and DNA synthesis and between p170 and cell growth control, we investigated in this study whether p170 regulates the synthesis of M2 and, thus, cell growth. We found that altering the expression level of p170 changes the synthesis rate of both M2 and DNA. Decreasing p170 expression in human lung cancer cell line H1299 and breast cancer cell line MCF7 significantly reversed their malignant growth phenotype. However, the overall [35S]methionine incorporation following dramatic decrease in p170 expression was only approximately 25% less than the control cells. These observations, together with our previous findings, suggest that p170 may regulate the translation of a subset mRNAs and its elevated expression level may be important for cancer cell growth and for maintaining their malignant phenotype.
Collapse
Affiliation(s)
- Zizheng Dong
- Department of Pharmacology and Toxicology, Indiana University Cancer Center, Walther Oncology Center/Walther Cancer Institute, Indiana University School of Medicine, 1044 W. Walnut Street, R4-166, Indianapolis, IN 46202, USA
| | | | | | | | | |
Collapse
|
7
|
Jovanović BZ, Perić-Grujić AA, Marinković AD, Vajs VV. Mass spectrometric study of some 4-pyrimidine carboxylic acids. RAPID COMMUNICATIONS IN MASS SPECTROMETRY : RCM 2002; 16:2044-2047. [PMID: 12391578 DOI: 10.1002/rcm.825] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Mass spectrometry has been applied in order to study the main fragmentation routes of some 4-pyrimidene carboxylic acids. Differences in fragmentation were caused by the nature of the substituent in position 2 of the pyrimidine ring, while the methyl group in position 1, 3 or 6 did not influence the fragmentation route.
Collapse
Affiliation(s)
- Bratislav Z Jovanović
- Faculty of Technology and Metallurgy, University of Belgrade, Karnegijeva 4, 11000 Belgrade, Yugoslavia
| | | | | | | |
Collapse
|
8
|
Trickett JI, Patel DD, Knight BL, Saggerson ED, Gibbons GF, Pease RJ. Characterization of the rodent genes for arylacetamide deacetylase, a putative microsomal lipase, and evidence for transcriptional regulation. J Biol Chem 2001; 276:39522-32. [PMID: 11481320 DOI: 10.1074/jbc.m101764200] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
In the current study, we have determined the cDNA and the genomic sequences of the arylacetamide deacetylase (AADA) gene in mice and rats. The AADA genes in the rat and mouse consist of five exons and have 2.4 kilobases of homologous promoter sequence upstream of the initiating ATG codon. AADA mRNA is expressed in hepatocytes, intestinal mucosal cells (probably enterocytes), the pancreas and also the adrenal gland. In mice, there is a diurnal rhythm in hepatic AADA mRNA concentration, with a maximum 10 h into the light (post-absorptive) phase. This diurnal regulation is attenuated in peroxisome proliferator-activated receptor alpha knockout mice. Intestinal but not hepatic AADA mRNA was increased following oral administration of the fibrate, Wy-14,643. The homology of AADA with hormone-sensitive lipase and the tissue distribution of AADA are consistent with the view that AADA plays a role in promoting the mobilization of lipids from intracellular stores and in the liver for assembling VLDL. This hypothesis is supported by parallel changes in AADA gene expression in animals with insulin-deficient diabetes and following treatment with orotic acid.
Collapse
Affiliation(s)
- J I Trickett
- Department of Biochemistry and Molecular Biology, University College London, Gower Street, London WC1E 6BT, UK
| | | | | | | | | | | |
Collapse
|