1
|
Zwickenpflug W, Hornung F, Hollaus A, Oswald MS, Chioato Z, Gudermann T, Högg C. Biosynthesis of vitamin B 3 and NAD +: incubating HepG2 cells with the alkaloid myosmine. JOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE 2024; 104:6844-6854. [PMID: 38578648 DOI: 10.1002/jsfa.13513] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/12/2023] [Revised: 03/26/2024] [Accepted: 04/03/2024] [Indexed: 04/06/2024]
Abstract
BACKGROUND In the kynurenine pathway, it is reported that the essential amino acid tryptophan forms nicotinic acid (NA, vitamin B3) in biological systems. This pathway is part of the de novo pathway to perform nicotinamide adenine dinucleotide (NAD+) biosynthesis. Additionally, biosynthesis of NAD+ via the Preiss-Handler pathway involves NA and its analogue nicotinamide, both designated as niacin. Previous attempts were successful in converting myosmine (MYO) by organic synthesis to NA, and the assumption was that the alkaloid MYO, which is taken in from food, can be converted into NA by biological oxidation. RESULT Incubation of HepG2 cells with MYO yielded NA. Moreover, a significant increase of NAD+ compared with the control has been found. CONCLUSION Hence, MYO could be assumed to be the hitherto unknown origin of an alternative NA biosynthesis additionally influencing NAD+ biosynthesis positively. This novel MYO pathway may open new perspectives to improve knowledge and relevance of NA and NAD+ biosynthesis and bioactivation in cells and, moreover, in food staples, food, and diet. © 2024 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.
Collapse
Affiliation(s)
- Wolfgang Zwickenpflug
- Walther Straub Institute of Pharmacology and Toxicology, Faculty of Medicine, LMU Munich, Munich, Germany
| | - Florian Hornung
- Walther Straub Institute of Pharmacology and Toxicology, Faculty of Medicine, LMU Munich, Munich, Germany
| | - Alexandra Hollaus
- Walther Straub Institute of Pharmacology and Toxicology, Faculty of Medicine, LMU Munich, Munich, Germany
| | - Michaela S Oswald
- Walther Straub Institute of Pharmacology and Toxicology, Faculty of Medicine, LMU Munich, Munich, Germany
| | - Zoé Chioato
- Walther Straub Institute of Pharmacology and Toxicology, Faculty of Medicine, LMU Munich, Munich, Germany
| | - Thomas Gudermann
- Walther Straub Institute of Pharmacology and Toxicology, Faculty of Medicine, LMU Munich, Munich, Germany
| | - Christof Högg
- Walther Straub Institute of Pharmacology and Toxicology, Faculty of Medicine, LMU Munich, Munich, Germany
- Department of Conservative Dentistry and Periodontology, University Hospital, LMU Munich, Munich, Germany
| |
Collapse
|
2
|
Richardot W, Yabes L, Wei HH, Dodder NG, Watanabe K, Cibor A, Schick SF, Novotny TE, Gersberg R, Hoh E. Leached Compounds from Smoked Cigarettes and Their Potential for Bioaccumulation in Rainbow Trout ( Oncorhynchus mykiss). Chem Res Toxicol 2023; 36:1703-1710. [PMID: 37827523 PMCID: PMC10664143 DOI: 10.1021/acs.chemrestox.3c00167] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2023] [Indexed: 10/14/2023]
Abstract
Cigarette butts are one of the most prevalent forms of litter worldwide and may leach toxic compounds when deposited in aquatic environments. Previous studies demonstrated that smoked cigarette leachate is toxic toward aquatic organisms. However, the specific bioavailable chemicals from the leachate and the potential for human and wildlife exposure through the food chain were unknown. Using a nontargeted analytical approach based on GC×GC/TOF-MS, 43 compounds were confirmed to leach from smoked cigarettes when exposed to a water source. Additionally, the bioaccumulation potential of organic contaminants in an edible fish, rainbow trout (Oncorhynchus mykiss), was assessed through direct exposure to the leachate of smoked cigarettes at 0.5 CB/L for 28 days. There was a significant reduction in fish mass among the exposed rainbow trout vs the control group (χ2 (1) = 5.3, p = 0.021). Both nontargeted and targeted chemical analysis of representative fish tissue identified four tobacco alkaloids, nicotine, nicotyrine, myosmine, and 2,2'-bipyridine. Their average tissue concentrations were 466, 55.4, 94.1, and 70.8 ng/g, respectively. This study identifies leached compounds from smoked cigarettes and demonstrates the uptake of specific chemicals in rainbow trout, thus suggesting a potential for accumulation in food webs, resulting in human and wildlife exposure.
Collapse
Affiliation(s)
- William
H. Richardot
- School
of Public Health, San Diego State University, San Diego, California 92182, United States
- San
Diego State University Research Foundation, San Diego, California 92182, United States
| | - Lenard Yabes
- School
of Public Health, San Diego State University, San Diego, California 92182, United States
| | - Hung-Hsu Wei
- School
of Public Health, San Diego State University, San Diego, California 92182, United States
| | - Nathan G. Dodder
- School
of Public Health, San Diego State University, San Diego, California 92182, United States
- San
Diego State University Research Foundation, San Diego, California 92182, United States
| | - Kayo Watanabe
- School
of Public Health, San Diego State University, San Diego, California 92182, United States
- San
Diego State University Research Foundation, San Diego, California 92182, United States
| | - Adrienne Cibor
- Enthalpy
Analytical (formerly Nautilus Environmental), San Diego, California 92120, United States
| | - Suzaynn F. Schick
- School
of Medicine, Division of Occupational and Environmental Medicine, University of California San Francisco, San Francisco, California 94143, United States
| | - Thomas E. Novotny
- School
of Public Health, San Diego State University, San Diego, California 92182, United States
| | - Richard Gersberg
- School
of Public Health, San Diego State University, San Diego, California 92182, United States
| | - Eunha Hoh
- School
of Public Health, San Diego State University, San Diego, California 92182, United States
| |
Collapse
|
3
|
Aral T, Önal G, Keskin E, Levent A. Firstly Electrochemical Examination of Myosmine at Glassy Carbon Electrode: Sensitive Determination in Tobacco Leaves by Differential Pulse Voltammetry. ELECTROANAL 2021. [DOI: 10.1002/elan.202100272] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Tarık Aral
- Department of Chemistry Faculty of Arts and Sciences Batman University Batman Turkey
| | - Günay Önal
- Department of Medical Services and Techniques Health Services Vocational School Batman University Batman Turkey
| | - Ertuğrul Keskin
- Adıyaman University Faculty of Pharmacy Department of Analytical Chemistry Adıyaman Turkey
| | - Abdulkadir Levent
- Department of Chemistry Faculty of Arts and Sciences Batman University Batman Turkey
| |
Collapse
|
4
|
Aral T, Önal G, Keskin E, Levent A. Firstly Electrochemical Examination of Myosmine at Glassy Carbon Electrode: Sensitive Determination in Tobacco Leaves by Differential Pulse Voltammetry. ELECTROANAL 2021; 33:2392-2399. [DOI: https:/doi.org/10.1002/elan.202100272] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2021] [Accepted: 08/12/2021] [Indexed: 07/01/2024]
Abstract
AbstractIn this study, the electrochemical properties of myosmine, one of the tobacco alkaloids, were investigated for the first time using cyclic voltammetry (CV) and differential pulse voltammetry (DPV) techniques on glassy carbon electrode (GCE). Using GCE with CV technique, it gave an irreversible reduction peak with diffusion control at about −1.38 V in Britton‐Robinson (BR, pH 12.0) medium. A good linear relationship between concentration and current in the range of 0.5 μM–3.5 μM in BR (pH 12.0) medium on GCE with DPV technique [Ip(μA)=0.847 C(μM)+0.114, r=0.995, n=7] has been observed. The proposed method has been successfully applied to tobacco leaves.
Collapse
Affiliation(s)
- Tarık Aral
- Department of Chemistry Faculty of Arts and Sciences Batman University Batman Turkey
| | - Günay Önal
- Department of Medical Services and Techniques Health Services Vocational School Batman University Batman Turkey
| | - Ertuğrul Keskin
- Adıyaman University Faculty of Pharmacy Department of Analytical Chemistry Adıyaman Turkey
| | - Abdulkadir Levent
- Department of Chemistry Faculty of Arts and Sciences Batman University Batman Turkey
| |
Collapse
|
5
|
Mateva R, Georgieva A, Iliev I, Toshkova R, Pajpanova T. Antiproliferative and apoptogenic effects of myosmine on erythroleukemia and hepatocellular carcinoma cells. BIOTECHNOL BIOTEC EQ 2019. [DOI: 10.1080/13102818.2019.1603082] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022] Open
Affiliation(s)
- Rada Mateva
- Department of Molecular Design and Biochemical Pharmacology, Institute of Molecular Biology, Bulgarian Academy of Sciences, Sofia, Bulgaria
| | - Ani Georgieva
- Department of Pathology, Institute of Experimental Morphology, Pathology and Anthropology with Museum, Bulgarian Academy of Sciences, Sofia, Bulgaria
| | - Ivan Iliev
- Department of Pathology, Institute of Experimental Morphology, Pathology and Anthropology with Museum, Bulgarian Academy of Sciences, Sofia, Bulgaria
| | - Reneta Toshkova
- Department of Pathology, Institute of Experimental Morphology, Pathology and Anthropology with Museum, Bulgarian Academy of Sciences, Sofia, Bulgaria
| | - Tamara Pajpanova
- Department of Molecular Design and Biochemical Pharmacology, Institute of Molecular Biology, Bulgarian Academy of Sciences, Sofia, Bulgaria
| |
Collapse
|
6
|
Nilsson R. Use of rodent data for cancer risk assessment of smokeless tobacco in the regulatory context. Regul Toxicol Pharmacol 2017. [PMID: 28625913 DOI: 10.1016/j.yrtph.2017.06.005] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
To support risk management decisions, information from different fields has been integrated in this presentation to provide a realistic quantitative cancer risk assessment of smokeless tobacco. Smoking among Swedish men is currently below 10%, while about 20% use a special smokeless tobacco (snus) as a substitute for cigarettes. Epidemiological data and molecular biomarkers demonstrate that rodent bioassays with tobacco specific nitrosamines (TSNA) overestimate cancer risk from snus by more than one order of magnitude. The underlying reasons are discussed. DNA damage constitutes a necessary, although not sufficient prerequisite for cancer initiation. Individuals who have not used tobacco exhibit DNA lesions identical with those induced by TSNA. No increase above this adduct background can be shown from snus, and extensive epidemiological studies in Sweden have failed to demonstrate elevated cancer risks even in long term users. A "bench mark" for acceptable risk of 1/10(6) derived from rodent data has been suggested when regulating snus. By relating similarly derived estimates for some food contaminants, the implementation even of a limit of 1/10(4) may be unrealistic. The management of smokeless tobacco products has rarely been based on a scientifically sound risk assessment, where attention is given to the outstandingly higher hazards associated with smoking.
Collapse
Affiliation(s)
- Robert Nilsson
- Vinča Institute of Nuclear Sciences, Laboratory for Physical Chemistry, University of Belgrade, Vinča, Serbia.
| |
Collapse
|
7
|
Zwickenpflug W, Högg C, Feierfeil J, Dachs M, Gudermann T. Isolation of Nicotinic Acid (Vitamin B3) and N-Propylamine after Myosmine Peroxidation. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2016; 64:178-184. [PMID: 26673015 DOI: 10.1021/acs.jafc.5b04913] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
The alkaloid myosmine (3-(1-pyrroline-2-yl)pyridine) is widespread in biological matrixes including foodstuffs and tobacco products. Some in vitro tests in cellular systems showed mutagenic activity for myosmine. Myosmine activation including peroxidation mechanism employs unstable oxazirane intermediates. The formation of minor metabolite 3-hydroxymethyl-pyridine in rat metabolism experiments as well as in in vitro peroxidation assays suggests its further oxidation to nicotinic acid and possible concomitant formation of n-propylamine. A sensitive high-performance liquid chromatography-ultraviolet (HPLC-UV) method was developed for the direct analysis of n-propylamine in the peroxidation assay solution of myosmine employing derivatization with 3,5-dinitrobenzoyl chloride. Additionally, during peroxidation procedures, formation of 3-pyridylmethanol to nicotinic acid, the essential vitamin B3, was observed and characterized using HPLC-UV and gas chromatography/mass spectrometry. This new reaction pathway may present further contribution to our knowledge of myosmine's significance in human food including its activation in human organism, foodstuffs, and biological systems.
Collapse
Affiliation(s)
- Wolfgang Zwickenpflug
- Walther-Straub-Institute of Pharmacology and Toxicology, University of Munich , Nussbaumstrasse 26, D-80336 Munich, Germany
| | - Christof Högg
- Walther-Straub-Institute of Pharmacology and Toxicology, University of Munich , Nussbaumstrasse 26, D-80336 Munich, Germany
| | - Johannes Feierfeil
- Walther-Straub-Institute of Pharmacology and Toxicology, University of Munich , Nussbaumstrasse 26, D-80336 Munich, Germany
| | - Manuel Dachs
- Walther-Straub-Institute of Pharmacology and Toxicology, University of Munich , Nussbaumstrasse 26, D-80336 Munich, Germany
| | - Thomas Gudermann
- Walther-Straub-Institute of Pharmacology and Toxicology, University of Munich , Nussbaumstrasse 26, D-80336 Munich, Germany
| |
Collapse
|
8
|
Abstract
Effects of Myosmine on Antioxidative Defence in Rat LiverMyosmine [3-(1-pyrrolin-2-yl) pyridine] is an alkaloid structurally similar to nicotine, which is known to induce oxidative stress. In this study we investigated the effects of myosmine on enzymatic and non-enzymatic antioxidative defence in rat liver. Wistar rats received a single i.p. injection of 19 mg kg-1 of myosmine and an oral dose of 190 mg kg-1 by gavage. Nicotine was used as a positive control. Through either route of administration, myosmine altered the hepatic function by decreasing the levels of reduced glutathione, superoxide dismutase, and glutathione peroxidase activities on one hand and by increasing malondialdehyde, catalase, and glutathione reductase activity on the other. Compared to control, both routes caused significant lipid peroxidation in the liver and altered hepatic enzymatic and non-enzymatic antioxidative defences. The pro-oxidant effects of myosmine were comparable with those of nicotine.
Collapse
|
9
|
Chen B, Xu Q. Protonating and determining myosmine intactly by association with citrate anion. Analyst 2011; 136:4846-54. [PMID: 21971428 DOI: 10.1039/c1an15611j] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2023]
Abstract
Myosmine can not be separated from nornicotine, nicotine and anabasine intactly by capillary zone electrophoresis (CZE) with a phosphate buffer. Using citrate solution at pH 6.5 as a CZE buffer, myosmine is protonated intactly by H(+), charged positively and then separated from other tobacco alkaloids on the baseline. Its sensitivity is ten times higher than gas chromatography (GC) with a nitrogen-phosphorus detector (NPD). The mechanism for protonating myosmine intactly is discussed and the utility of the new method is testified, too.
Collapse
Affiliation(s)
- Bo Chen
- College of Chemistry and Chemical Engineering, Hunan Normal University, P. R. China
| | | |
Collapse
|
10
|
Koleva II, van Beek TA, Soffers AEMF, Dusemund B, Rietjens IMCM. Alkaloids in the human food chain - Natural occurrence and possible adverse effects. Mol Nutr Food Res 2011; 56:30-52. [DOI: 10.1002/mnfr.201100165] [Citation(s) in RCA: 109] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2011] [Revised: 06/03/2011] [Accepted: 06/06/2011] [Indexed: 01/19/2023]
|
11
|
Nilsson R. The molecular basis for induction of human cancers by tobacco specific nitrosamines. Regul Toxicol Pharmacol 2011; 60:268-80. [DOI: 10.1016/j.yrtph.2011.02.014] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2010] [Revised: 02/24/2011] [Accepted: 02/28/2011] [Indexed: 10/18/2022]
|
12
|
Liao X, Zhu J, Rubab M, Feng YL, Poon R. An analytical method for the measurement of acid metabolites of tryptophan-NAD pathway and related acids in urine. J Chromatogr B Analyt Technol Biomed Life Sci 2010; 878:1003-6. [PMID: 20299289 DOI: 10.1016/j.jchromb.2010.02.017] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2009] [Revised: 02/09/2010] [Accepted: 02/10/2010] [Indexed: 10/19/2022]
Abstract
An analytical method has been developed for the measurements of five urinary acids namely, quinolinic acid, picolinic acid, nicotinic acid, 2-pyridylacetic acid and 3-pyridylacetic acid. The high performance liquid chromatograph-electrospray ionization mass spectrometry was operated in positive polarity under selected ion monitoring mode, with a column flow rate of 0.2 ml/min and an injection volume of 20 microl. The method used isotope-labelled picolinic acid (PA-d(4)) and nicotinic acid (NA-d(4)) as internal standards for the quantification. The sample preparation involved parallel use of two different types of mixed-mode solid phase extraction cartridges (Strata-X-AW for the extraction of quinolinic acid, and Strata-X-C for the remaining acids). Quantitative analysis of five target acids in several human and rat urine samples showed that the levels of acids were relatively uniform among rats while larger variations were observed for human samples.
Collapse
Affiliation(s)
- Xiangjun Liao
- Exposure and Biomonitoring Division, Health Canada, 50 Colombine Driveway, Ottawa, Canada
| | | | | | | | | |
Collapse
|
13
|
Schütte-Borkovec K, Heppel CW, Heling AK, Richter E. Analysis of myosmine, cotinine and nicotine in human toenail, plasma and saliva. Biomarkers 2009; 14:278-84. [PMID: 19476410 DOI: 10.1080/13547500902898164] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Myosmine is a minor tobacco alkaloid with widespread occurrence in the human diet. Myosmine is genotoxic in human cells and is readily nitrosated and peroxidated yielding reactive intermediates with carcinogenic potential. For biomonitoring of short-term and long-term exposure, analytical methods were established for determination of myosmine together with nicotine and cotinine in plasma, saliva and toenail by gas chromatography-mass spectrometry (GC/MS). Validation of the method with samples of 14 smokers and 10 non-smokers showed smoking-dependent differences of myosmine in toenails (66 +/- 56 vs 21 +/- 15 ng g(-1), p <0.01) as well as saliva (2.54 +/- 2.68 vs 0.73 +/- 0.65 ng ml(-1), p <0.01). However, these differences were much smaller than those with nicotine (1971 +/- 818 vs 132 +/- 82 ng g(-1), p <0.0001) and cotinine (1237 +/- 818 vs <35 ng g(-1)) in toenail and those of cotinine (97.43 +/- 84.54 vs 1.85 +/- 4.50 ng ml(-1), p <0.0001) in saliva. These results were confirmed in plasma samples from 84 patients undergoing gastro-oesophageal endoscopy. Differences between 25 smokers and 59 non-smokers are again much lower for myosmine (0.30 +/- 0.35 vs 0.16 +/- 0.18 ng ml(-1), p <0.05) than for cotinine (54.67 +/- 29.63 vs 0.61 +/- 1.82 ng ml(-1), p <0.0001). In conclusion, sources other than tobacco contribute considerably to the human body burden of myosmine.
Collapse
|
14
|
Hecht SS, Han S, Kenney PMJ, Wang M, Lindgren B, Wang Y, Lao Y, Hochalter JB, Upadhyaya P. Investigation of the reaction of myosmine with sodium nitrite in vitro and in rats. Chem Res Toxicol 2007; 20:543-9. [PMID: 17291014 PMCID: PMC2518846 DOI: 10.1021/tx600328e] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Previous studies have shown that the minor tobacco alkaloid myosmine (5) reacts with NaNO2 in the presence of acid to yield 4-hydroxy-1-(3-pyridyl)-1-butanone (HPB, 8) via 4-(3-pyridyl)-4-oxobutanediazohydroxide (7). Intermediate 7 is also formed in the metabolism of the tobacco-specific nitrosamines N'-nitrosonornicotine (NNN, 1) and 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK, 2), resulting in pyridyloxobutylation of DNA and Hb. These pyridyloxobutyl adducts can be quantified by analyzing HPB released upon acid treatment of DNA or base treatment of Hb. Quantitation of HPB-releasing DNA and Hb adducts has been used to assess the metabolic activation of NNN and NNK in smokers and smokeless tobacco users. Because myosmine is found in the diet as well as in tobacco products, it has been suggested that nitrosation of myosmine could lead to the formation of HPB-releasing adducts in people not exposed to tobacco products. We investigated the nitrosation of myosmine in vitro and in vivo in rats. The reaction of myosmine with NaNO2 under acidic conditions produced HPB, as previously reported. A new product was identified as 3'-oximinomyosmine (11) based on its spectral properties. NNN was not detected. Groups of rats were treated with NNN, NNK, myosmine, NaNO2, or combinations of myosmine and NaNO2. HPB-releasing Hb and DNA adducts were clearly detected in the rats treated with NNN or NNK, but we found no evidence for production of these adducts from the combination of myosmine plus NaNO2. The results of this study do not support the hypothesis that exposure to dietary myosmine could lead to HPB-releasing DNA or Hb adducts in humans.
Collapse
Affiliation(s)
- Stephen S Hecht
- The Cancer Center, University of Minnesota, Minneapolis, Minnesota 55455, USA.
| | | | | | | | | | | | | | | | | |
Collapse
|
15
|
Glas S, Tyroller S, Zwickenpflug W, Steiner K, Kiefer G, Richter E. Tissue distribution and excretion of myosmine after i.v. administration to Long–Evans rats using quantitative whole-body autoradiography. Arch Toxicol 2006; 81:151-61. [PMID: 16902802 DOI: 10.1007/s00204-006-0137-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2006] [Accepted: 07/13/2006] [Indexed: 10/24/2022]
Abstract
Occurrence of the tobacco alkaloid myosmine has been proven in various staple foods, vegetables and fruits. Myosmine can be easily activated by nitrosation yielding 4-hydroxy-1-(3-pyridyl)-butanone (HPB) and the esophageal carcinogen N'-nitrosonornicotine. Most of the reaction products after myosmine peroxidation were also identified as urinary metabolites after oral administration to rats. Whole-body autoradiography with freeze dried or multiple solvent extracted tissue sections was used to trace [2'-(14)C]myosmine (0.1 mCi/kg bw) 0.1, 0.25, 1, 4 and 24 h after i.v. injection in Long-Evans rats. In addition, in vitro binding of radioactivity to esophageal and eye tissue was determined and excretion of radioactivity via urine and feces was quantified. Radioactivity is rapidly eliminated by renal excretion. Approximately 30% of the administered radioactivity was recovered in urine within the first 4 h and excretion with urine (72%) and feces (15%) was nearly complete after 24 h. A rapid concentration of radioactivity can be seen in the stomach and in the salivary and lachrymal glands. Rats killed 1 and 4 h after treatment showed by far the highest labeling in the accessory genital gland. High levels of nonextractable radioactivity were present in esophageal tissue and melanin. The half lives for the disappearance of radioactivity from various tissues are in the order of about 1 h. Eye and esophagus sections both showed nonextractable labeling after in vitro incubation with (14)C-myosmine. In conclusion, the toxicological significance of myosmine accumulation in esophagus and accessory genital gland requires further investigations. Hair analysis might be applicable for myosmine biomonitoring, because of possible enrichment in melanin containing tissues.
Collapse
Affiliation(s)
- Susanna Glas
- Walther Straub Institute of Pharmacology and Toxicology, Ludwig-Maximilians University of Munich, Goethestrasse 33, 80336, Munich, Germany.
| | | | | | | | | | | |
Collapse
|