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Manier SK, Valdiviezo JA, Vollmer AC, Eckstein N, Meyer MR. Analytical toxicology of the semi-synthetic cannabinoid hexahydrocannabinol studied in human samples, pooled human liver S9 fraction, rat samples and drug products using HPLC-HRMS-MS. J Anal Toxicol 2023; 47:818-825. [PMID: 37864499 DOI: 10.1093/jat/bkad079] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2023] [Revised: 09/27/2023] [Accepted: 10/04/2023] [Indexed: 10/23/2023] Open
Abstract
Hexahydrocannabinol (HHC) is an emerging semi-synthetic cannabinoid, which is obtained from cyclization of cannabidiol and subsequent hydrogenation. As a potentially legal alternative of ∆9-tetrahydrocannabinol (∆9-THC), it is increasingly seized in the USA and Europe. The aims of this study were to investigate the metabolism of HHC in pooled human liver S9 fraction (pHLS9), rat and human samples. Additionally, a locally obtained low-THC cannabis product was investigated, which was advertised with an elevated concentration of HHC. Overall, HHC formed an 11-hydroxy (HO) metabolite, as well as a carboxy metabolite. While only the parent compound was detected in rat urine and feces, the hydroxy metabolite was additionally detected in pHLS9 and human plasma. The carboxy metabolite was only detectable in human plasma. The metabolism corresponded well to that of ∆9-THC, although glucuronidation and the formation of an 8-HO metabolite were not observed. Detectability of HHC and its carboxy metabolite in rat urine was investigated using gas chromatography-mass spectrometry, but neither the parent compound nor the metabolite were detectable. The investigated low-THC cannabis product appeared to be an actual cannabis product since, in addition to HHC, cannabinol, cannabidiol and ∆9-THC were detected after qualitative analysis. Estimation of its content revealed not only 30.6% of HHC but also 4% of ∆9-THC.
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Affiliation(s)
- Sascha K Manier
- Department of Experimental and Clinical Toxicology, Institute of Experimental and Clinical Pharmacology and Toxicology, Saarland University, Center for Molecular Signaling (PZMS), Kirrberber Str. 100, Homburg, Saar 66421, Germany
| | - Johannes Angert Valdiviezo
- Applied Pharmacy, University of Applied Sciences Kaiserslautern, Campus Pirmasens, Carl-Schurz-Str. 10-16, Pirmasens 66953, Germany
| | - Aline C Vollmer
- Department of Experimental and Clinical Toxicology, Institute of Experimental and Clinical Pharmacology and Toxicology, Saarland University, Center for Molecular Signaling (PZMS), Kirrberber Str. 100, Homburg, Saar 66421, Germany
| | - Niels Eckstein
- Applied Pharmacy, University of Applied Sciences Kaiserslautern, Campus Pirmasens, Carl-Schurz-Str. 10-16, Pirmasens 66953, Germany
| | - Markus R Meyer
- Department of Experimental and Clinical Toxicology, Institute of Experimental and Clinical Pharmacology and Toxicology, Saarland University, Center for Molecular Signaling (PZMS), Kirrberber Str. 100, Homburg, Saar 66421, Germany
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Wania F, Lei YD, Baskaran S, Sangion A. Identifying organic chemicals not subject to bioaccumulation in air-breathing organisms using predicted partitioning and biotransformation properties. INTEGRATED ENVIRONMENTAL ASSESSMENT AND MANAGEMENT 2022; 18:1297-1312. [PMID: 34783167 PMCID: PMC9541168 DOI: 10.1002/ieam.4555] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/18/2021] [Revised: 11/12/2021] [Accepted: 11/15/2021] [Indexed: 05/12/2023]
Abstract
Because the respiration processes contributing to the elimination of organic chemicals deviate between air- and water-breathing organisms, existing and widely used procedures for identifying chemicals not subject to bioaccumulation in aquatic organisms based on the octanol-water partition ratio KOW need to be complemented with similar procedures for organisms respiring air. Here, we propose such a procedure that relies on the comparison of a compound's predicted KOW , octanol-air partition ratio KOA , and biotransformation half-life HLB with three threshold values, below which elimination is judged to be sufficiently rapid to prevent bioaccumulation. The method allows for the consideration of the effect of dissociation on the efficiency of urinary and respiratory elimination. Explicit application of different types of the prediction error, such as the 95% prediction interval or the standard error, allows for variable tolerance for false-negative decisions, that is, the potential to judge a chemical as not bioaccumulative even though it is. A test with a set of more than 1000 diverse organic chemicals confirms the applicability of the prediction methods for a wide range of compounds and the procedure's ability to categorize approximately four-fifth of compounds as being of no bioaccumulation concern, suggesting its usefulness to screen large numbers of commercial chemicals to identify those worthy of further scrutiny. The test also demonstrates that a screening based solely on KOW and KOA would be far less effective because the fraction of chemicals that can be judged as sufficiently volatile and/or sufficiently water soluble for rapid respiratory and urinary elimination based on the partitioning properties predicted for their neutral form is relatively small. Future improvements of the proposed procedure depend largely on the development of prediction methods for the biotransformation kinetics in air-breathing organisms and for the potential for renal reabsorption. Integr Environ Assess Manag 2022;18:1297-1312. © 2021 The Authors. Integrated Environmental Assessment and Management published by Wiley Periodicals LLC on behalf of Society of Environmental Toxicology & Chemistry (SETAC).
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Affiliation(s)
- Frank Wania
- Department of Physical and Environmental SciencesUniversity of Toronto ScarboroughTorontoOntarioCanada
| | - Ying Duan Lei
- Department of Physical and Environmental SciencesUniversity of Toronto ScarboroughTorontoOntarioCanada
| | - Sivani Baskaran
- Department of Physical and Environmental SciencesUniversity of Toronto ScarboroughTorontoOntarioCanada
| | - Alessandro Sangion
- Department of Physical and Environmental SciencesUniversity of Toronto ScarboroughTorontoOntarioCanada
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Kang WN, Jin L, Ma HY, Li GQ. Integrated Microbiome-Metabolome Analysis Reveals Stage-Dependent Alterations in Bacterial Degradation of Aromatics in Leptinotarsa decemlineata. Front Physiol 2021; 12:739800. [PMID: 34658924 PMCID: PMC8515180 DOI: 10.3389/fphys.2021.739800] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2021] [Accepted: 08/16/2021] [Indexed: 11/16/2022] Open
Abstract
To avoid potential harm during pupation, the Colorado potato beetle Leptinotarsa decemlineata lives in two different habitats throughout its developmental excursion, with the larva and adult settling on potato plants and the pupa in soil. Potato plants and agricultural soil contain a specific subset of aromatics. In the present study, we intended to determine whether the stage-specific bacterial flora plays a role in the catabolism of aromatics in L. decemlineata. Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis of the operational taxonomic units (OTUs) obtained by sequencing of culture-independent 16S rRNA region enriched a group of bacterial genes involved in the elimination of mono- and polycyclic aromatics at the pupal stage compared with those at the larval and adult periods. Consistently, metabolome analysis revealed that dozens of monoaromatics such as styrene, benzoates, and phenols, polycyclic aromatics, for instance, naphthalene and steroids, were more abundant in the pupal sample. Moreover, a total of seven active pathways were uncovered in the pupal specimen. These ways were associated with the biodegradation of benzoate, 4-methoxybenzoate, fluorobenzoates, styrene, vanillin, benzamide, and naphthalene. In addition, the metabolomic profiles and the catabolism abilities were significantly different in the pupae where their bacteria were removed by a mixture of three antibiotics. Therefore, our data suggested the stage-dependent alterations in bacterial breakdown of aromatics in L. decemlineata.
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Affiliation(s)
- Wei-Nan Kang
- Education Ministry Key Laboratory of Integrated Management of Crop Diseases and Pests, College of Plant Protection, Nanjing Agricultural University, Nanjing, China
| | - Lin Jin
- Education Ministry Key Laboratory of Integrated Management of Crop Diseases and Pests, College of Plant Protection, Nanjing Agricultural University, Nanjing, China
| | - Hong-Yu Ma
- Public Laboratory Platform, College of Plant Protection, Nanjing Agricultural University, Nanjing, China
| | - Guo-Qing Li
- Education Ministry Key Laboratory of Integrated Management of Crop Diseases and Pests, College of Plant Protection, Nanjing Agricultural University, Nanjing, China
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Accumulated ambient air pollution and colon cancer incidence in Thailand. Sci Rep 2020; 10:17765. [PMID: 33082474 PMCID: PMC7575563 DOI: 10.1038/s41598-020-74669-7] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2020] [Accepted: 09/30/2020] [Indexed: 12/17/2022] Open
Abstract
This research examined the relationship between colon cancer risks and pollution in various areas of Thailand, using satellites to gather quantities of aerosols in the atmosphere. Bayesian hierarchical spatio-temporal model and the Poisson log-linear model were used to examine the incidence rates of colon cancer standardized by national references; from the database of the National Health Security Office, Ministry of Public Health of Thailand and NASA's database from aerosol diagnostics model. Modern-Era Retrospective Analysis for Research and Applications, Version 2 (MERRA-2) was used to explore disease-gender-specific spatio-temporal patterns of colon cancer incidences and accumulated air pollution-related cancers in Thailand between 2010 and 2016. A total of 59,605 patients were selected for the study. Due to concerns regarding statistical reliability between aerosol diagnostics model and colon cancer incidences, the posterior probabilities of risk appeared the most in dust PM2.5. It could be interpreted as relative risk in every increase of 10 μg/m3 in black carbon, organic carbon, and dust-PM2.5 levels were associated respectively with an increase of 4%, 4%, and 15% in the risks of colon cancer. A significant increase in the incidence of colon cancer with accumulated ambient air quality raised concerns regarding the prevention of air pollution. This study utilized data based on the incidences of colon cancer; the country's database and linked cancer data to pollution. According to the database from NASA's technology, this research has never been conducted in Thailand.
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Lee D, Jacobs DR, Lind L, Lind PM. Lipophilic Environmental Chemical Mixtures Released During Weight‐Loss: The Need to Consider Dynamics. Bioessays 2020; 42:e1900237. [DOI: 10.1002/bies.201900237] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2019] [Revised: 03/06/2020] [Indexed: 12/25/2022]
Affiliation(s)
- Duk‐Hee Lee
- Department of Preventive MedicineSchool of MedicineKyungpook National University Daegu 41944 Korea
| | - David R Jacobs
- Division of Epidemiology and Community HealthSchool of Public HealthUniversity of Minnesota Minneapolis Minnesota 55454 USA
| | - Lars Lind
- Department of Medical SciencesCardiovascular EpidemiologyUppsala University Uppsala 75237 Sweden
| | - P. Monica Lind
- Department of Medical SciencesOccupational and Environmental MedicineUppsala University Uppsala 75185 Sweden
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Liang Y, Liu D, Zhan J, Luo M, Han J, Wang P, Zhou Z. New insight into the mechanism of POP-induced obesity: Evidence from DDE-altered microbiota. CHEMOSPHERE 2020; 244:125123. [PMID: 32050320 DOI: 10.1016/j.chemosphere.2019.125123] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/10/2019] [Revised: 09/27/2019] [Accepted: 10/13/2019] [Indexed: 06/10/2023]
Abstract
Although epidemiological studies demonstrate that persistent organic pollutants (POPs) could lead to metabolic syndrome, the mechanism has remained unclear. The dysbiosis of gut microbiota and the lipid metabolome have been put forward in the pathophysiology of metabolic syndrome. In this study, we used dichlorodiphenyldichloroethylene (DDE) as an example to study the effects of POP-impaired microbial composition and metabolome homeostasis on metabolic syndrome. The results showed that DDE exposure increased body weight and fat content and impaired glucose homeostasis. Further investigation revealed that DDE induced gut dysbiosis as indicated by an increased Firmicutes-to-Bacteroidetes ratio, which may impact energy harvest efficiency. Meanwhile, the plasma lipid metabolome profile was significantly altered by DDE. Furthermore, phosphatidylcholine, phosphatidylserine, phosphatidylethanolamine, and triacylglycerol were identified as key metabolites affected by DDE treatment, and these altered lipid metabolites were highly correlated with changed microbiota composition. This study provides novel insight into the underlying mechanism of POP-induced obesity and diabetes, pointing to gut microbiota as one of the targets.
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Affiliation(s)
- Yiran Liang
- Beijing Advanced Innovation Center for Food Nutrition and Human Health, College of Science, China Agricultural University, No. 2, West Yuanmingyuan Road, Beijing, 100193, PR China; College of Chemistry and Biological Engineering, University of Science and Technology Beijing, No. 30, Xueyuan Road, Beijing, 100083, PR China
| | - Donghui Liu
- Beijing Advanced Innovation Center for Food Nutrition and Human Health, College of Science, China Agricultural University, No. 2, West Yuanmingyuan Road, Beijing, 100193, PR China
| | - Jing Zhan
- Beijing Advanced Innovation Center for Food Nutrition and Human Health, College of Science, China Agricultural University, No. 2, West Yuanmingyuan Road, Beijing, 100193, PR China
| | - Mai Luo
- Beijing Advanced Innovation Center for Food Nutrition and Human Health, College of Science, China Agricultural University, No. 2, West Yuanmingyuan Road, Beijing, 100193, PR China
| | - Jiajun Han
- Beijing Advanced Innovation Center for Food Nutrition and Human Health, College of Science, China Agricultural University, No. 2, West Yuanmingyuan Road, Beijing, 100193, PR China
| | - Peng Wang
- Beijing Advanced Innovation Center for Food Nutrition and Human Health, College of Science, China Agricultural University, No. 2, West Yuanmingyuan Road, Beijing, 100193, PR China
| | - Zhiqiang Zhou
- Beijing Advanced Innovation Center for Food Nutrition and Human Health, College of Science, China Agricultural University, No. 2, West Yuanmingyuan Road, Beijing, 100193, PR China.
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Lee DH, Porta M, Jacobs DR, Vandenberg LN. Chlorinated persistent organic pollutants, obesity, and type 2 diabetes. Endocr Rev 2014; 35:557-601. [PMID: 24483949 PMCID: PMC5393257 DOI: 10.1210/er.2013-1084] [Citation(s) in RCA: 300] [Impact Index Per Article: 30.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Persistent organic pollutants (POPs) are lipophilic compounds that travel with lipids and accumulate mainly in adipose tissue. Recent human evidence links low-dose POPs to an increased risk of type 2 diabetes (T2D). Because humans are contaminated by POP mixtures and POPs possibly have nonmonotonic dose-response relations with T2D, critical methodological issues arise in evaluating human findings. This review summarizes epidemiological results on chlorinated POPs and T2D, and relevant experimental evidence. It also discusses how features of POPs can affect inferences in humans. The evidence as a whole suggests that, rather than a few individual POPs, background exposure to POP mixtures-including organochlorine pesticides and polychlorinated biphenyls-can increase T2D risk in humans. Inconsistent statistical significance for individual POPs may arise due to distributional differences in POP mixtures among populations. Differences in the observed shape of the dose-response curves among human studies may reflect an inverted U-shaped association secondary to mitochondrial dysfunction or endocrine disruption. Finally, we examine the relationship between POPs and obesity. There is evidence in animal studies that low-dose POP mixtures are obesogenic. However, relationships between POPs and obesity in humans have been inconsistent. Adipose tissue plays a dual role of promoting T2D and providing a relatively safe place to store POPs. Large prospective studies with serial measurements of a broad range of POPs, adiposity, and clinically relevant biomarkers are needed to disentangle the interrelationships among POPs, obesity, and the development of T2D. Also needed are laboratory experiments that more closely mimic real-world POP doses, mixtures, and exposure duration in humans.
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Affiliation(s)
- Duk-Hee Lee
- Department of Preventive Medicine (D.-H.L.), School of Medicine, Kyungpook National University, Daegu 700-422, Korea; BK21 Plus KNU Biomedical Convergence Program, Department of Biomedical Science (D.-H.L.), Kyungpook National University, Korea; Hospital del Mar Institute of Medical Research (M.P.), School of Medicine, Universitat Autonoma de Barcelona, and Centro de Investigación Biomédica en Red de Epidemiología y Salud Pública, Barcelona 08193, Spain; Division of Epidemiology (D.R.J.), School of Public Health, University of Minnesota, Minneapolis, Minnesota 55455; Department of Nutrition (D.R.J.), University of Oslo, 0313 Oslo, Norway; and University of Massachusetts-Amherst (L.N.V.), School of Public Health, Division of Environmental Health Sciences, Amherst, Massachusetts 01003
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8
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An assessment of the intestinal lumen as a site for intervention in reducing body burdens of organochlorine compounds. ScientificWorldJournal 2013; 2013:205621. [PMID: 23476122 PMCID: PMC3582106 DOI: 10.1155/2013/205621] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2012] [Accepted: 12/30/2012] [Indexed: 11/17/2022] Open
Abstract
Many individuals maintain a persistent body burden of organochlorine compounds (OCs) as well as other lipophilic compounds, largely as a result of airborne and dietary exposures. Ingested OCs are typically absorbed from the small intestine along with dietary lipids. Once in the body, stored OCs can mobilize from adipose tissue storage sites and, along with circulating OCs, are delivered into the small intestine via hepatic processing and biliary transport. Retained OCs are also transported into both the large and small intestinal lumen via non-biliary mechanisms involving both secretion and desquamation from enterocytes. OCs and some other toxicants can be reabsorbed from the intestine, however, they take part in enterohepatic circulation(EHC). While dietary fat facilitates the absorption of OCs from the small intestine, it has little effect on OCs within the large intestine. Non-absorbable dietary fats and fat absorption inhibitors, however, can reduce the re-absorption of OCs and other lipophiles involved in EHC and may enhance the secretion of these compounds into the large intestine—thereby hastening their elimination. Clinical studies are currently underway to determine the efficacy of using non-absorbable fats and inhibitors of fat absorption in facilitating the elimination of persistent body burdens of OCs and other lipophilic human contaminants.
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Lee HS, Lee JC, Lee IK, Moon HB, Chang YS, Jacobs DR, Lee DH. Associations among organochlorine pesticides, Methanobacteriales, and obesity in Korean women. PLoS One 2011; 6:e27773. [PMID: 22114690 PMCID: PMC3219687 DOI: 10.1371/journal.pone.0027773] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2011] [Accepted: 10/25/2011] [Indexed: 12/31/2022] Open
Abstract
BACKGROUND Although Methanobacteriales in the gut has recently been linked to obesity, no study has examined the hypothesis that waist circumference, a marker of visceral obesity, are positively associated with Methanobacteriales in the general population. Since Methanobacteriales increase in a petroleum-contaminated environment to biodegrade petroleum as one way of autopurification, we also hypothesized that high body burden of highly lipophilic petroleum-based chemicals like organochlorine pesticides (OCPs) is associated with higher levels of Methanobacteriales in the gut. METHODOLOGY/PRINCIPAL FINDINGS Among 83 Korean women who visited a community health service center for a routine health checkup, quantitative real-time PCR (qPCR) based on 16S rDNA was used to quantify Methanobacteriales in feces. Nine OCPs were measured in both serum and feces of 16 subjects. Methanobacteriales were detected in 32.5% (27/83 women). Both BMI and waist circumference among women with Methanobacteriales were significantly higher than in women without Methanobacteriales (P = 0.04 and P = 0.01, respectively). Also, Methanobacteriales levels in feces were positively associated with BMI and waist circumference (r = +0.23 and P = 0.03 for both). Furthermore, there were significant correlations between feces Methanobacteriales levels and serum concentrations of most OCPs, including with cis-nonachlor (r = +0.53, P<0.05), oxychlordane (r = +0.46, P<0.1), and trans-nonachlor (r = +0.43, P<0.1). Despite high correlations of serum and feces concentrations of most OCPs, feces OCP concentrations were not clearly associated with feces Methanobacteriales levels. CONCLUSION/SIGNIFICANCE In this cross-sectional study, the levels of Methanobacteriales in the human gut were associated with higher body weight and waist circumference. In addition, serum OCP concentrations were positively correlated with levels of Methanobacteriales. There may be a meaningful link among body burden of OCP, Methanobacteriales in the gut, and obesity in the general population.
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Affiliation(s)
- Hae-Sook Lee
- Department of Public Health Graduate School, Kyungpook National University, Daegu, Korea
| | - Je-Chul Lee
- Department of Microbiology, Kyungpook National University School of Medicine, Daegu, Korea
| | - In-Kyu Lee
- Department of Endocrinology, Kyungpook National University School of Medicine, Daegu, Korea
| | - Hyo-Bang Moon
- Department of Environmental Marine Sciences, College of Science and Technology, Hanyang University, Ansan, Korea
| | - Yoon-Seok Chang
- School of Environmental Science and Engineering, POSTECH, Pohang, Korea
| | - David R. Jacobs
- Division of Epidemiology, School of Public Health, University of Minnesota, Minneapolis, Minnesota, United States of America
- Department of Nutrition, University of Oslo, Oslo, Norway
| | - Duk-Hee Lee
- Department of Preventative Medicine, School of Medicine, Kyungpook National University, Daegu, Korea
- * E-mail:
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Abstract
There is compelling evidence that various chemical agents are important determinants of myriad health afflictions--several xenobiotics have the potential to disrupt reproductive, developmental, and neurological processes and some agents in common use have carcinogenic, epigenetic, endocrine-disrupting, and immune-altering action. Some toxicants appear to have biological effect at miniscule levels and certain chemical compounds are persistent and bioaccumulative within the human body. Despite escalating public health measures to preclude further exposures, many people throughout the world have already accrued a significant body burden of toxicants, placing them at potential health risk. As a result, increasing discussion is underway about possible interventions to facilitate elimination of persistent toxicants from the human organism in order to obviate health affliction and to potentially ameliorate chronic degenerative illness. An overview of the clinical aspects of detoxification is presented with discussion of established and emerging interventions for the elimination of persistent xenobiotics. Potential therapies to circumvent enterohepatic recirculation and a case report highlighting a clinical outcome associated with detoxification are also presented for consideration.
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Affiliation(s)
- Stephen J Genuis
- University of Alberta, 2935-66 Street, Edmonton, Alberta, Canada.
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11
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Opinion of the Scientific Panel on contaminants in the food chain [CONTAM] related to Hexachlorobenzene as undesirable substance in animal feed. EFSA J 2006. [DOI: 10.2903/j.efsa.2006.402] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
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Juan CY, Thomas GO, Sweetman AJ, Jones KC. An input-output balance study for PCBs in humans. ENVIRONMENT INTERNATIONAL 2002; 28:203-214. [PMID: 12222617 DOI: 10.1016/s0160-4120(02)00030-2] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Polychlorinated biphenyl (PCB) input-output balance studies were performed on five male volunteers, aged between 24 and 30, for periods of 8-14 days in 1998. Dietary exposure was quantified by the duplicate meals method and varied between 220 and 460 ng of sigmaPCB (sum of 20 congeners) per day for each of the five individuals over the study period. Dietary intake was dominated by congeners 118, 138, 153 and 180. Average faecal outputs for the five volunteers were 50-290 ng of sigmaPCB (sum of 20 congeners) per day for each of the five individuals over the same period and was dominated by the same four congeners. Whilst the total PCB fluxes were therefore into the body (i.e., accumulation), important differences were noted for different individual congeners. PCBs 44, 47, 49, 52, 60, 66, 101, 105, 110, 118, 149, 151 and 183 all showed net absorption for all five volunteers. Some congeners showed a net absorption in some of the individuals but net excretion in others, as seen by other workers. These congeners (PCBs 138, 153, 180, 187 and 194) are all higher chlorinated congeners and lack meta-para-vicinal hydrogen atoms. There were differences in the net absorption/excretion between individuals, which appeared to be a function of body fat index (BFI). The volunteers with the lowest BFIs showed net excretion for the greatest number of congeners, whilst the individual with the highest BFI was a net absorber of all the congeners studied. The problems in determining and interpreting absorption efficiency values for use in quantitative exposure assessments are discussed. Various factors that influence net absorption of PCBs and other persistent organic pollutants are identified. These include compound properties (including susceptibility to metabolism), the individual's fat status and balance, exposure history and diet.
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Affiliation(s)
- Ching-Yi Juan
- Environmental Science Department, Institute of Environmental and Natural Science, Lancaster University, UK
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13
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Abstract
Lipophilic toxins have been introduced into the environment both as functional compounds, such as pesticides, and as industrial waste from incineration or the manufacture of electrical transformer components. Among these substances are compounds that are carcinogenic and that affect the endocrine system. Accidental high exposures of humans to some lipophilic toxins have produced overt disease symptoms including chloracne and altered liver function. These toxic materials have been the recent focus of international effort to reduce or eliminate classes of halogenated hydrocarbons from the environment. Evidence of the widespread distribution of lipophilic toxins in the biosphere has been obtained by analyses of human tissues and human milk. The principal route of entry of lipophilic toxins into humans is through the food chain, and most of them are stored in adipose tissue. A common route of excretion is in bile, but there is also evidence of nonbiliary excretion into the intestine. Enterohepatic circulation of many of these compounds slows their removal from the body. Substances that interrupt the enterohepatic circulation of compounds that enter the intestine by the biliary and nonbiliary routes increase the rate of their removal from the body and reduce their storage half-lives. Reduction in body fat, along with these dietary substances that interrupt enterohepatic circulation, further enhances the excretion rate. Areas for further research include optimizing regimens for body burden reductions, understanding the nature of nonbiliary excretion, and following the effects of tissue redistribution during loss of body fat.
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Affiliation(s)
- R J Jandacek
- The University of Cincinnati, Department of Pathology, Ohio 45267, USA.
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Abraham K, Knoll A, Ende M, Päpke O, Helge H. Intake, fecal excretion, and body burden of polychlorinated dibenzo-p-dioxins and dibenzofurans in breast-fed and formula-fed infants. Pediatr Res 1996; 40:671-9. [PMID: 8910931 DOI: 10.1203/00006450-199611000-00005] [Citation(s) in RCA: 67] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
To assess toxicokinetics of polychlorinated dibenzo-p-dioxins (PCDDs) and dibenzofurans (PCDFs), oral intake and fecal excretion were measured in two breast-fed infants and one formula-fed infant during the 1st y of life. The intake of these compounds was up to 50 times higher in the breast-fed infants. In these children, fecal excretion of the main tetra- to hexachlorinated congeners was less than 9% of the intake at age of 1 and 5 mo, indicating almost complete intestinal absorption during breast-feeding. In contrast, distinctly higher fecal excretion rates were observed for the hepta- and octachlorinated compounds. Despite much lower PCDD/PCDF intake after weaning, concentrations in stool fat did not decrease substantially. We conclude that concentrations in fecal fat more or less reflect those in body fat. Additionally, PCDD/PCDF concentrations were measured in blood fat of all infants (and in a second formula-fed baby) at the age of 11 mo. International toxicity equivalent (I-TEq) concentrations in the formula-fed infants were less than 25% of maternal values and about 10 times lower than in the infants breast-fed for 6-7 mo. In the latter, a distinct accumulation was found for the tetra- to hexachlorinated congeners compared with maternal concentrations. We conclude that accumulation of PCDDs and PCDFs in infants is as high as expected on the basis of intake data and assuming complete absorption and negligible elimination during the 1st y of life.
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Affiliation(s)
- K Abraham
- Children's Hospital, Virchow-Klinikum, Humboldt-Universität Berlin, Germany
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15
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Huckle KR, Morrison BJ, Warburton PA. The percutaneous fate of the rodenticide flocoumafen in the rat: role of non-biliary intestinal excretion. Xenobiotica 1989; 19:63-74. [PMID: 2756718 DOI: 10.3109/00498258909034677] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
1. Appreciable penetration of radioacticity occurred through rat skin following percutaneous administration of 14C-flocoumafen. At 7 days after dosing 12% of the administered radioactivity remained at the site of application, while 25% was located in the liver as unchanged flocoumafen. 2. Excretion of flocoumafen metabolites via the urine accounted for 10% dose over the 7 day experiment, this is some 30-fold greater than that seen after a single oral dose. 3. Unchanged flocoumafen comprised the major product detected in faeces. Biliary elimination was a very minor route of excretion and did not account for all of the unmodified flocoumafen present in faeces. 4. Considerable amounts of unchanged flocoumafen found associated with the contents of the large intestine after intraperitoneal administration to rats fitted with biliary fistulae indicates that, in the intact rat, flocoumafen enters the intestine by a non-biliary intestinal excretion mechanism.
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Affiliation(s)
- K R Huckle
- Shell Research Limited, Sittingbourne Research Centre, Kent, UK
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