1
|
Gould S, Templin MV. Off target toxicities and links with physicochemical properties of medicinal products, including antibiotics, oligonucleotides, lipid nanoparticles (with cationic and/or anionic charges). Data review suggests an emerging pattern. Toxicol Lett 2023; 384:14-29. [PMID: 37454775 DOI: 10.1016/j.toxlet.2023.07.011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2023] [Revised: 07/10/2023] [Accepted: 07/12/2023] [Indexed: 07/18/2023]
Abstract
Toxicology is an essential part of any drug development plan. Circumnavigating the risk of failure because of a toxicity issue can be a challenge, and failure in late development is extremely costly. To identify potential risks, it requires more than just understanding the biological target. The toxicologist needs to consider a compound's structure, it's physicochemical properties (including the impact of the overall formulation), as well as the biological target (e.g., receptor interactions). Understanding the impact of the physicochemical properties can be used to predict potential toxicities in advance by incorporating key endpoints in early screening strategies and/or used to compare toxicity profiles across lead candidates. This review discussed the risks of off-target and/or non-specific toxicities that may be associated with the physicochemical properties of compounds, especially those carrying dominant positive or negative charges, including amphiphilic small molecules, peptides, oligonucleotides and lipids/liposomes/lipid nanoparticles. The latter of which are being seen more and more in drug development, including the recent Covid pandemic, where mRNA and lipid nanoparticle technology is playing more of a role in vaccine development. The translation between non-clinical and clinical data is also considered, questioning how a physicochemical driven toxicity may be more universal across species, which means that such toxicity may be reassuringly translatable between species and as such, this information may also be considered as a support to the 3 R's, particularly in the early screening stages of a drug development plan.
Collapse
|
2
|
Davidsen JM, Cohen SM, Eisenbrand G, Fukushima S, Gooderham NJ, Guengerich FP, Hecht SS, Rietjens IMCM, Rosol TJ, Harman CL, Taylor SV. FEMA GRAS assessment of derivatives of basil, nutmeg, parsley, tarragon and related allylalkoxybenzene-containing natural flavor complexes. Food Chem Toxicol 2023; 175:113646. [PMID: 36804339 DOI: 10.1016/j.fct.2023.113646] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2022] [Revised: 01/26/2023] [Accepted: 01/30/2023] [Indexed: 02/18/2023]
Abstract
In 2015, the Expert Panel of the Flavor and Extract Manufacturers Association (FEMA) initiated a program for the re-evaluation of the safety of over 250 natural flavor complexes (NFCs) used as flavoring ingredients in food. In this publication, tenth in the series, NFCs containing a high percentage of at least one naturally occurring allylalkoxybenzene constituent with a suspected concern for genotoxicity and/or carcinogenicity are evaluated. In a related paper, ninth in the series, NFCs containing anethole and/or eugenol and relatively low percentages of these allylalkoxybenzenes are evaluated. The Panel applies the threshold of toxicological concern (TTC) concept and evaluates relevant toxicology data on the NFCs and their respective constituent congeneric groups. For NFCs containing allylalkoxybenzene constituent(s), the estimated intake of the constituent is compared to the TTC for compounds with structural alerts for genotoxicity and when exceeded, a margin of exposure (MOE) is calculated. BMDL10 values are derived from benchmark dose analyses using Bayesian model averaging for safrole, estragole and methyl eugenol using EPA's BMDS software version 3.2. BMDL10 values for myristicin, elemicin and parsley apiole were estimated by read-across using relative potency factors. Margins of safety for each constituent congeneric group and MOEs for each allylalkoxybenzene constituent for each NFC were determined that indicate no safety concern. The scope of the safety evaluation contained herein does not include added use in dietary supplements or any products other than food. Ten NFCs, derived from basil, estragon (tarragon), mace, nutmeg, parsley and Canadian snakeroot were determined or affirmed as generally recognized as safe (GRAS) under their conditions of intended use as flavor ingredients based on an evaluation of each NFC and the constituents and congeneric groups therein.
Collapse
Affiliation(s)
- Jeanne M Davidsen
- Flavor and Extract Manufacturers Association, 1101 17th Street, N.W., Suite 700, Washington, D.C, 20036, USA
| | - Samuel M Cohen
- Havlik-Wall Professor of Oncology, Dept. of Pathology and Microbiology, University of Nebraska Medical Center, 983135 Nebraska Medical Center, Omaha, NE, 68198-3135, USA
| | - Gerhard Eisenbrand
- University of Kaiserslautern, Germany (Retired), Kühler Grund 48/1, 69126, Heidelberg, Germany
| | - Shoji Fukushima
- Japan Bioassay Research Center, 2445 Hirasawa, Hadano, Kanagawa, 257-0015, Japan
| | - Nigel J Gooderham
- Dept. of Metabolism, Digestion, Reproduction, Imperial College London, Sir Alexander Fleming Building, London, SW7 2AZ, United Kingdom
| | - F Peter Guengerich
- Dept. of Biochemistry, Vanderbilt University School of Medicine, Nashville, TN, 37232-0146, USA
| | - Stephen S Hecht
- Masonic Cancer Center and Dept. of Laboratory Medicine and Pathology, Cancer and Cardiovascular Research Building, 2231 6th St, S.E, Minneapolis, MN, 55455, USA
| | - Ivonne M C M Rietjens
- Division of Toxicology, Wageningen University, Stippeneng 6708 WE, Wageningen, the Netherlands
| | - Thomas J Rosol
- Department of Biomedical Sciences, Heritage College of Osteopathic Medicine, Ohio University, 1 Ohio University, Athens, OH, 45701, USA
| | - Christie L Harman
- Flavor and Extract Manufacturers Association, 1101 17th Street, N.W., Suite 700, Washington, D.C, 20036, USA
| | - Sean V Taylor
- Scientific Secretary to the FEMA Expert Panel, 1101 17th Street, N.W., Suite 700, Washington, D.C, 20036, USA.
| |
Collapse
|
3
|
Bus JS, Gollapudi BB, Hard GC. Methyl-tert-butyl ether (MTBE): integration of rat and mouse carcinogenicity data with mode of action and human and rodent bioassay dosimetry and toxicokinetics indicates MTBE is not a plausible human carcinogen. JOURNAL OF TOXICOLOGY AND ENVIRONMENTAL HEALTH. PART B, CRITICAL REVIEWS 2022; 25:135-161. [PMID: 35291916 DOI: 10.1080/10937404.2022.2041516] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Methyl-tert-butyl ether (MTBE) is a fuel oxygenate used in non-United States geographies. Multiple health reviews conclude that MTBE is not a human-relevant carcinogen, and this review provides updated mode of action (MOA), exposure, dosimetry and risk perspectives supporting those conclusions. MTBE is non-genotoxic and has large margins of exposure between blood concentrations at the overall rat 400 ppm inhalation NOAEL and blood concentrations in typical workplace or general population exposures. Non-cancer and threshold cancer hazard quotients range from a high of 0.046 for fuel-pump gasoline station attendants and are 100-1,000-fold lower for general population exposures. Cancer risks conservatively assuming genotoxicity for these same scenarios are all less than 1 × 10-6. The onset of MTBE nonlinear toxicokinetics (TK) in rats at inhalation exposures less than 3,000 ppm, a dose that is also not practically achievable in fuel-use scenarios, indicates that high-dose specific male rat kidney and testes (3,000 and 8,000 ppm) and female mouse liver tumors (8000 ppm) are not quantitatively relevant to humans. Mode of action analyses also indicate MTBE male rat kidney tumors, and lesser so female mouse liver tumors, are not qualitatively relevant to humans. Thus, an integrated analysis of the toxicology, exposure/dosimetry, TK, and MOA data indicates that MTBE presents minimal human cancer and non-cancer risks.
Collapse
Affiliation(s)
- James S Bus
- Toxicology and Mechanistic Biology, Exponent Inc, Apex, NC, USA
| | | | | |
Collapse
|
4
|
Cooper TK, Meyerholz DK, Beck AP, Delaney MA, Piersigilli A, Southard TL, Brayton CF. Research-Relevant Conditions and Pathology of Laboratory Mice, Rats, Gerbils, Guinea Pigs, Hamsters, Naked Mole Rats, and Rabbits. ILAR J 2022; 62:77-132. [PMID: 34979559 DOI: 10.1093/ilar/ilab022] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2021] [Accepted: 05/12/2021] [Indexed: 12/31/2022] Open
Abstract
Animals are valuable resources in biomedical research in investigations of biological processes, disease pathogenesis, therapeutic interventions, safety, toxicity, and carcinogenicity. Interpretation of data from animals requires knowledge not only of the processes or diseases (pathophysiology) under study but also recognition of spontaneous conditions and background lesions (pathology) that can influence or confound the study results. Species, strain/stock, sex, age, anatomy, physiology, spontaneous diseases (noninfectious and infectious), and neoplasia impact experimental results and interpretation as well as animal welfare. This review and the references selected aim to provide a pathology resource for researchers, pathologists, and veterinary personnel who strive to achieve research rigor and validity and must understand the spectrum of "normal" and expected conditions to accurately identify research-relevant experimental phenotypes as well as unusual illness, pathology, or other conditions that can compromise studies involving laboratory mice, rats, gerbils, guinea pigs, hamsters, naked mole rats, and rabbits.
Collapse
Affiliation(s)
- Timothy K Cooper
- Department of Comparative Medicine, Penn State Hershey Medical Center, Hershey, PA, USA
| | - David K Meyerholz
- Department of Pathology, University of Iowa Roy J. and Lucille A. Carver College of Medicine, Iowa City, Iowa, USA
| | - Amanda P Beck
- Department of Pathology, Yeshiva University Albert Einstein College of Medicine, Bronx, New York, USA
| | - Martha A Delaney
- Zoological Pathology Program, University of Illinois at Urbana-Champaign College of Veterinary Medicine, Urbana-Champaign, Illinois, USA
| | - Alessandra Piersigilli
- Laboratory of Comparative Pathology and the Genetically Modified Animal Phenotyping Service, Memorial Sloan Kettering Cancer Center, New York, New York, USA
| | - Teresa L Southard
- Department of Biomedical Sciences, Cornell University College of Veterinary Medicine, Ithaca, New York, USA
| | - Cory F Brayton
- Department of Molecular and Comparative Pathobiology, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| |
Collapse
|
5
|
Hard GC. Confounders for kidney carcinogenesis in rodent cancer bioassays. J Toxicol Pathol 2022; 35:1-6. [PMID: 35221490 PMCID: PMC8828606 DOI: 10.1293/tox.2021-0000] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2021] [Accepted: 09/29/2021] [Indexed: 11/24/2022] Open
Abstract
In the long-term safety testing of chemicals for carcinogenicity the toxicologist needs
to be aware of a number of scenarios where renal tubule tumors, or their precursors, arise
that are not due to a carcinogenic action of the test article. Situations producing false
positive results in the kidney include exacerbation of chronic progressive nephropathy
(CPN) in rats, confusion of atypical tubule hyperplasia (the obligate precursor of renal
tubule tumor) with foci of benign CPN-related renal tubule cell proliferation, inclusion
of spontaneous tumor entities, such as the amphophilic-vacuolar tumor, in the test article
tumor count, the possibility of a link between spontaneous forms of tubule dilatation and
renal tubule tumor formation in mice, and the supposed predictivity of chemically-induced
karyomegaly for renal carcinogenicity in both rats and mice. Examples of these misleading
situations are described and discussed.
Collapse
Affiliation(s)
- Gordon C Hard
- Private Toxicology Consultant, 203 Paku Drive, Tairua 3508, New Zealand
| |
Collapse
|
6
|
O’Donoghue JL, Beevers C, Buard A. Hvdroquinone: Assessment of genotoxic potential in the in vivo alkaline comet assay. Toxicol Rep 2021; 8:206-214. [PMID: 33489780 PMCID: PMC7810912 DOI: 10.1016/j.toxrep.2021.01.005] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2020] [Revised: 08/19/2020] [Accepted: 01/07/2021] [Indexed: 11/26/2022] Open
Abstract
Hydroquinone (HQ) exposure is common as it is a natural component of plant-based foods and is used in some fingernail polishes, hair dyes, and skin lighteners. Industrially it is used as an antioxidant, polymerization inhibitor, and reducing agent. The current study was undertaken to determine whether HQ may cause DNA damage in an in vivo comet assay in F344 rats. DNA strand breaks were assessed in the duodenum as a direct tissue contact site, the testes, and the liver and kidneys, which were tumor sites in bioassays. Rats were exposed to HQ by gavage at 0, 105, 210, or 420 mg/kg/day. At all dose levels, mean % tail intensity and tail moment values for all tissues in animals given HQ were similar to the control. There were no statistically significant increases in tail intensity in any tissue following HQ treatment of male and female rat and data for all animals fell within the available historical control ranges for each tissue. There was no evidence of induction of DNA damage in cells isolated from duodenum, kidney or liver of male and female rats or in the testes of male rats following exposure to HQ at a dose levels up to 420 mg/kg/day, which caused acute renal necrosis.
Collapse
Affiliation(s)
- John L. O’Donoghue
- Department of Environmental Medicine, School of Medicine and Dentistry, University of Rochester, Box EHSC, 601 Elmwood Ave., Rochester, NY, 14642, United States
| | - Carol Beevers
- Exponent International Ltd, The Lenz, Hornbeam Park, Harrogate, HG2 8RE, United Kingdom
| | - Annie Buard
- Solvay RICL - Antenne de GENAS, 85 Avenue des Frères Perret, 69192, Saint-Fons CEDEX, France
| |
Collapse
|
7
|
Beyer LA, Greenberg GI, Beck BD. A Comparative Cancer Risk Evaluation of MTBE and Other Compounds (Including Naturally Occurring Compounds) in Drinking Water in New Hampshire. RISK ANALYSIS : AN OFFICIAL PUBLICATION OF THE SOCIETY FOR RISK ANALYSIS 2020; 40:2584-2597. [PMID: 33270937 DOI: 10.1111/risa.13570] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/29/2017] [Revised: 11/15/2019] [Accepted: 02/06/2020] [Indexed: 06/12/2023]
Abstract
Methyl tert-butyl ether (MTBE) was added to gasoline in New Hampshire (NH) between 1995 and 2006 to comply with the oxygenate requirements of the 1990 Amendments to the Clean Air Act. Leaking tanks and spills released MTBE into groundwater, and as a result, MTBE has been detected in drinking water in NH. We conducted a comparative cancer risk assessment and a margin-of-safety (MOS) analysis for several constituents, including MTBE, detected in NH drinking water. Using standard risk assessment methods, we calculated cancer risks from exposure to 12 detected volatile organic compounds (VOCs), including MTBE, and to four naturally occurring compounds (i.e., arsenic, radium-226, radium-228, and radon-222) detected in NH public water supplies. We evaluated exposures to a hypothetical resident ingesting the water, dermally contacting the water while showering, and inhaling compounds volatilizing from water in the home. We then compared risk estimates for MTBE to those of the other 15 compounds. From our analysis, we concluded that the high-end cancer risk from exposure to MTBE in drinking water is lower than the risks from all the other VOCs evaluated and several thousand times lower than the risks from exposure to naturally occurring constituents, including arsenic, radium, and radon. We also conducted an MOS analysis in which we compared toxicological points of departure to the NH maximum contaminant level (MCL) of 13 µg/L. All of the MOSs were greater than or equal to 160,000, indicating a large margin of safety and demonstrating the health-protectiveness of the NH MCL for MTBE.
Collapse
Affiliation(s)
- Leslie A Beyer
- Boston Environmental & Engineering Associates, Inc., Waltham, MA, USA
| | | | | |
Collapse
|
8
|
Reavill DR, Lennox AM. Disease Overview of the Urinary Tract in Exotic Companion Mammals and Tips on Clinical Management. Vet Clin North Am Exot Anim Pract 2020; 23:169-193. [PMID: 31759446 PMCID: PMC7110585 DOI: 10.1016/j.cvex.2019.09.003] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Diseases of the urinary tract are reviewed, covering infectious (bacterial, viral, parasitic), degenerative, congenital, metabolic, nutritional, neoplastic, obstructive, and toxic causes. Some clinical presentations and diagnostic procedures are described for ferrets, rabbits, guinea pigs, hamsters, mice, rats, chinchillas, hedgehogs, and sugar gliders, as well as therapies.
Collapse
Affiliation(s)
- Drury R Reavill
- Zoo/Exotic Pathology Service, 6020 Rutland Drive #14, Carmichael, CA 95608-0515, USA.
| | - Angela M Lennox
- Avian and Exotic Animal Clinic of Indianapolis, 9330 Waldemar Road, Indianapolis, IN 46268, USA
| |
Collapse
|
9
|
Mog SR, Zang YJ. Safety Assessment of Food Additives: Case Example With Myrcene, a Synthetic Flavoring Agent. Toxicol Pathol 2019; 47:1035-1037. [PMID: 31645206 DOI: 10.1177/0192623319879634] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
In the United States, the Food and Drug Administration (FDA) regulates the safe use of food ingredients, including food additives. Food additives are subject to FDA premarket review and approval, a process conducted by FDA scientists to evaluate the additive's safety for the intended conditions of use. Typically, an acceptable daily intake level is established by toxicologists based on the highest no observable adverse effect level for the most sensitive noncancer toxicity end point determined from a pivotal nonclinical study with application of an appropriate safety factor. Utilizing other information, including the additive's use and exposure levels, a safety determination (reasonable certainty of no harm) is made. During ongoing safety assessments, pathologists are often consulted by toxicologists for case-specific reasons, which may include verifying that an observed pathological effect is treatment related and adverse, confirming the determination of the pivotal study, endorsing a mode of action, or evaluating the human relevance of a toxicological effect found in experimental animals. Last year, the FDA took regulatory action to no longer allow the use of the food additive myrcene, a synthetic flavoring agent, based on results from National Toxicology Program carcinogenicity studies. The cancer and noncancer end points from the rat studies are discussed.
Collapse
Affiliation(s)
- Steven R Mog
- US Food and Drug Administration, Center for Food Safety and Applied Nutrition, Office of Food Additive Safety, College Park, MD, USA
| | - Yu Janet Zang
- US Food and Drug Administration, Center for Food Safety and Applied Nutrition, Office of Food Additive Safety, College Park, MD, USA
| |
Collapse
|
10
|
Bastaki M, Api AM, Aubanel M, Bauter M, Cachet T, Demyttenaere JCR, Diop MM, Harman CL, Hayashi SM, Krammer G, Lu V, Marone PA, Mendes O, Renskers KJ, Schnabel J, Tsang SY, Taylor SV. Dietary administration of β-caryophyllene and its epoxide to Sprague-Dawley rats for 90 days. Food Chem Toxicol 2019; 135:110876. [PMID: 31610257 DOI: 10.1016/j.fct.2019.110876] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2019] [Revised: 10/04/2019] [Accepted: 10/06/2019] [Indexed: 02/01/2023]
Abstract
Two independent 90-day GLP-compliant studies were conducted in Sprague-Dawley rats with β-caryophyllene or β-caryophyllene epoxide, two common flavoring and fragrance materials. Dietary concentrations of β-caryophyllene were 3500; 7000; and 21,000 ppm for males and 3500; 14,000; and 56,000 ppm for females. Dietary concentrations of β-caryophyllene epoxide were 1750; 10,500; and 21,000 ppm. There were no deaths or clinical toxicity attributable to either substance administration. Statistically significant, dose-dependent reductions in body weight, body weight gain, food consumption, and food efficiency at the highest dietary concentrations of β-caryophyllene, but not of β-caryophyllene epoxide, were attributed to palatability issues. Neither β-caryophyllene nor β-caryophyllene epoxide influenced estrus cyclicity or sperm parameters. Macroscopic and microscopic findings were primarily related to changes in the kidneys of male rats, consistent with α2u-globulin nephropathy, and in the liver of male and female rats, including hepatocyte hypertrophy at the middle and high intake levels. These changes correlated with increased absolute and relative organ weights. Since the kidney findings were a species- and sex-specific effect, the NOAEL in each study was based on hepatocyte hypertrophy at the two highest dietary concentrations and were determined to be 222 mg/kg bw/day for β-caryophyllene and 109 mg/kg bw/day for β-caryophyllene epoxide.
Collapse
Affiliation(s)
- Maria Bastaki
- International Organization of the Flavor Industry, 1101 17th Street N.W., Suite 700, Washington, DC, 20036, USA
| | - Anne Marie Api
- Research Institute for Fragrance Materials, Inc., 50 Tice Boulevard, Woodcliff Lake, NJ, 07677, USA
| | - Michel Aubanel
- Kerry Flavours France, Zl du Plan BP 82067, 63 Avenue Jean Maubert, 06131, Grasse Cedex, France
| | - Mark Bauter
- Product Safety Labs, 2394 US Highway 130, Dayton, NJ, 08810, USA
| | - Thierry Cachet
- International Organization of the Flavor Industry, Avenue des Arts 6, B-1210, Brussels, Belgium
| | | | | | - Christie L Harman
- Flavor and Extract Manufacturers Association, 1101 17th Street N.W., Suite 700, Washington, DC, 20036, USA
| | - Shim-Mo Hayashi
- Japan Flavor and Fragrance Materials Association, Sankeinihonbashi Bldg. 6F, 4-7-1 Nihonbashi-Honcho, Chuo-ku, Tokyo, 103-0023, Japan
| | - Gerhard Krammer
- Symrise AG, Muehlenfeldstrasse 1, 37603, Holzminden, Germany
| | - Vivian Lu
- International Organization of the Flavor Industry, 1101 17th Street N.W., Suite 700, Washington, DC, 20036, USA
| | - Palma Ann Marone
- Product Safety Labs, 2394 US Highway 130, Dayton, NJ, 08810, USA
| | - Odete Mendes
- Product Safety Labs, 2394 US Highway 130, Dayton, NJ, 08810, USA
| | - Kevin J Renskers
- Takasago International Corporation, 4 Volvo Drive, Rockleigh, NJ, 07647, USA
| | - Jürgen Schnabel
- Givaudan International SA, Kemptpark 50, 8310 Kemptthal, Switzerland
| | - Sai Yee Tsang
- Research Institute for Fragrance Materials, Inc., 50 Tice Boulevard, Woodcliff Lake, NJ, 07677, USA
| | - Sean V Taylor
- International Organization of the Flavor Industry, 1101 17th Street N.W., Suite 700, Washington, DC, 20036, USA.
| |
Collapse
|
11
|
Cohen SM, Eisenbrand G, Fukushima S, Gooderham NJ, Guengerich FP, Hecht SS, Rietjens IMCM, Bastaki M, Davidsen JM, Harman CL, McGowen MM, Taylor SV. FEMA GRAS assessment of natural flavor complexes: Mint, buchu, dill and caraway derived flavoring ingredients. Food Chem Toxicol 2019; 135:110870. [PMID: 31604112 DOI: 10.1016/j.fct.2019.110870] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2019] [Revised: 09/18/2019] [Accepted: 10/02/2019] [Indexed: 02/08/2023]
Abstract
In 2015, the Expert Panel of the Flavor and Extract Manufacturers Association (FEMA) initiated a re-evaluation of the safety of over 250 natural flavor complexes (NFCs) used as flavor ingredients. NFC flavor materials include a variety of essential oils and botanical extracts. The re-evaluation of NFCs is conducted based on a constituent-based procedure outlined in 2005 and updated in 2018 that evaluates the safety of NFCs for their intended use as flavor ingredients. This procedure is applied in the re-evaluation of the generally recognized as safe (GRAS) status of NFCs with constituent profiles that are dominated by alicyclic ketones such as menthone and carvone, secondary alcohols such as menthol and carveol, and related compounds. The FEMA Expert Panel affirmed the GRAS status of Peppermint Oil (FEMA 2848), Spearmint Oil (FEMA 3032), Spearmint Extract (FEMA 3031), Cornmint Oil (FEMA 4219), Erospicata Oil (FEMA 4777), Curly Mint Oil (FEMA 4778), Pennyroyal Oil (FEMA 2839), Buchu Leaves Oil (FEMA 2169), Caraway Oil (FEMA 2238) and Dill Oil (FEMA 2383) and determined FEMA GRAS status for Buchu Leaves Extract (FEMA 4923), Peppermint Oil, Terpeneless (FEMA 4924) and Spearmint Oil, Terpeneless (FEMA 4925).
Collapse
Affiliation(s)
- Samuel M Cohen
- Havlik-Wall Professor of Oncology, Dept. of Pathology and Microbiology, University of Nebraska Medical Center, 983135 Nebraska Medical Center, Omaha, NE, 68198-3135, USA
| | - Gerhard Eisenbrand
- Food Chemistry & Toxicology, University of Kaiserslautern, Kaiserslautern, Germany
| | - Shoji Fukushima
- Japan Bioassay Research Center, 2445 Hirasawa, Hadano, Kanagawa, 257-0015, Japan
| | - Nigel J Gooderham
- Dept. of Metabolism, Digestion, and Reproduction, Imperial College London, Sir Alexander Fleming Building, London, SW7 2AZ, United Kingdom
| | - F Peter Guengerich
- Dept. of Biochemistry, Vanderbilt University School of Medicine, Nashville, TN, 37232-0146, USA
| | - Stephen S Hecht
- Masonic Cancer Center and Dept. of Laboratory Medicine and Pathology, University of Minnesota, MMC 806, 420 Delaware St., S.E., Minneapolis, MN, 55455, USA
| | - Ivonne M C M Rietjens
- Division of Toxicology, Wageningen University, Tuinlaan 5, 6703 HE, Wageningen, the Netherlands
| | - Maria Bastaki
- Flavor and Extract Manufacturers Association, 1101 17th Street NW, Suite 700, Washington, DC, 20036, USA
| | - Jeanne M Davidsen
- Flavor and Extract Manufacturers Association, 1101 17th Street NW, Suite 700, Washington, DC, 20036, USA
| | - Christie L Harman
- Flavor and Extract Manufacturers Association, 1101 17th Street NW, Suite 700, Washington, DC, 20036, USA
| | - Margaret M McGowen
- Flavor and Extract Manufacturers Association, 1101 17th Street NW, Suite 700, Washington, DC, 20036, USA
| | - Sean V Taylor
- Flavor and Extract Manufacturers Association, 1101 17th Street NW, Suite 700, Washington, DC, 20036, USA.
| |
Collapse
|
12
|
Hard GC, Cohen SM, Ma J, Yu F, Arnold LL, Banton MI. Histopathology re-examination of the NTP toxicity/carcinogenicity studies of tert-butyl alcohol to identify renal tumor and toxicity modes of action. Regul Toxicol Pharmacol 2018; 102:65-73. [PMID: 30590081 DOI: 10.1016/j.yrtph.2018.12.011] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2018] [Revised: 12/07/2018] [Accepted: 12/15/2018] [Indexed: 11/18/2022]
Abstract
Tert-butyl alcohol (TBA) targets the rat kidney following repeated exposures, including renal tubule tumors. The mode of action (MOA) of these tumors, concluded by a pathology working group, involves both alpha2u-globulin nephropathy (α2u-gN) and exacerbated chronic progressive nephropathy (CPN), but has been disputed and an undefined MOA proposed. This study further reviews the histology slides of male and female rat kidneys from the NTP drinking water 13-week toxicity and 2-year carcinogenicity studies, including the 15-month interim sacrifice group. The papillary epithelial lining alteration formerly referred to as "transitional cell hyperplasia" develops as part of advanced CPN and does not represent a separate toxicity. No changes were observed in the kidney pelvis urothelium. The only alterations in subchronic male rats involved α2u-gN and CPN, without test article-related alterations in females. Focused examination of areas of parenchyma unaffected by CPN in TBA-treated male and female rats of the chronic studies revealed no renal tubule abnormalities other than from the effects of α2u-gN and CPN. Unrelated to toxicity were spontaneous amphophilic or vacuolar tubule proliferative lesions. All observed TBA-associated non-neoplastic and neoplastic histopathological changes in the kidney can be explained by α2u-gN or enhanced CPN, neither of which are relevant to humans.
Collapse
Affiliation(s)
| | - Samuel M Cohen
- Department of Pathology and Microbiology, University of Nebraska Medical Center, Omaha, NE, 68198-3135, USA; Havlik-Wall Professor of Oncology, USA.
| | - Jihyun Ma
- Department of Biostatistics, College of Public Health, University of Nebraska Medical Center, Omaha, NE, 68198-4375, USA
| | - Fang Yu
- Department of Biostatistics, College of Public Health, University of Nebraska Medical Center, Omaha, NE, 68198-4375, USA
| | - Lora L Arnold
- Department of Pathology and Microbiology, University of Nebraska Medical Center, Omaha, NE, 68198-3135, USA
| | | |
Collapse
|
13
|
FEMA GRAS assessment of natural flavor complexes: Citrus-derived flavoring ingredients. Food Chem Toxicol 2018; 124:192-218. [PMID: 30481573 DOI: 10.1016/j.fct.2018.11.052] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2018] [Revised: 11/19/2018] [Accepted: 11/23/2018] [Indexed: 01/06/2023]
Abstract
In 2015, the Expert Panel of the Flavor and Extract Manufacturers Association (FEMA) initiated a re-evaluation of the safety of over 250 natural flavor complexes (NFCs) used as flavoring ingredients. This publication is the first in a series and summarizes the evaluation of 54 Citrus-derived NFCs using the procedure outlined in Smith et al. (2005) and updated in Cohen et al. (2018) to evaluate the safety of naturally-occurring mixtures for their intended use as flavoring ingredients. The procedure relies on a complete chemical characterization of each NFC intended for commerce and organization of each NFC's chemical constituents into well-defined congeneric groups. The safety of the NFC is evaluated using the well-established and conservative threshold of toxicological concern (TTC) concept in addition to data on absorption, metabolism and toxicology of members of the congeneric groups and the NFC under evaluation. As a result of the application of the procedure, 54 natural flavor complexes derived from botanicals of the Citrus genus were affirmed as generally recognized as safe (GRAS) under their conditions of intended use as flavoring ingredients based on an evaluation of each NFC and the constituents and congeneric groups therein.
Collapse
|
14
|
Bastaki M, Aubanel M, Bauter M, Cachet T, Demyttenaere J, Diop MM, Harman CL, Hayashi SM, Krammer G, Li X, Llewellyn C, Mendes O, Renskers KJ, Schnabel J, Smith BP, Taylor SV. Absence of renal adverse effects from β-myrcene dietary administration in OECD guideline-compliant subchronic toxicity study. Food Chem Toxicol 2018; 120:222-229. [DOI: 10.1016/j.fct.2018.07.004] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2018] [Revised: 06/22/2018] [Accepted: 07/02/2018] [Indexed: 01/22/2023]
|
15
|
Abstract
The important renal tumors that can be induced by exposure of rats to chemical carcinogens are renal tubule tumors (RTTs) derived from tubule epithelium; renal pelvic carcinoma derived from the urothelial lining of the pelvis; renal mesenchymal tumors (RMTs) derived from the interstitial connective tissue; and nephroblastoma derived from the metanephric primordia. However, almost all of our knowledge concerning mechanisms of renal carcinogenesis in the rodent pertains to the adenomas and carcinomas originating from renal tubule epithelium. Currently, nine mechanistic pathways can be identified in either the rat or mouse following chemical exposure. These include direct DNA reactivity, indirect DNA reactivity through free radical formation, multiphase bioactivation involving glutathione conjugation, mitotic disruption, sustained cell proliferation from direct cytotoxicity, sustained cell proliferation by disruption of a physiologic process (alpha 2u-globulin nephropathy), exaggerated pharmacologic response, species-dominant metabolic pathway, and chemical exacerbation of chronic progressive nephropathy. Spontaneous occurrence of RTTs in the rat will be included since one example is a confounder for interpreting kidney tumor results in chemical carcinogenicity studies in rats.
Collapse
|
16
|
Schafer KA, Eighmy J, Fikes JD, Halpern WG, Hukkanen RR, Long GG, Meseck EK, Patrick DJ, Thibodeau MS, Wood CE, Francke S. Use of Severity Grades to Characterize Histopathologic Changes. Toxicol Pathol 2018. [PMID: 29529947 DOI: 10.1177/0192623318761348] [Citation(s) in RCA: 107] [Impact Index Per Article: 17.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
The severity grade is an important component of a histopathologic diagnosis in a nonclinical toxicity study that helps distinguish treatment-related effects from background findings and aids in determining adverse dose levels during hazard characterization. Severity grades should be assigned based only on the extent (i.e., amount and complexity) of the morphologic change in the examined tissue section(s) and be clearly defined in the pathology report for critical lesions impacting study interpretation. However, the level of detail provided and criteria by which severity grades are assigned can vary, which can lead to inappropriate comparisons and confusion when evaluating pathology results. To help address this issue, a Working Group of the Society of Toxicologic Pathology's Scientific and Regulatory Policy Committee was formed to provide a "points to consider" article on the assignment and application of pathology severity grades. Overall, the Working Group supports greater transparency and consistency in the reporting of grading scales and provides recommendations to improve selection of diagnoses requiring more detailed severity criteria. This information should enhance the overall understanding by toxicologic pathologists, toxicologists, and regulatory reviewers of pathology findings and thereby improve effective communication in regulatory submissions.
Collapse
Affiliation(s)
| | - John Eighmy
- 2 Covance Laboratories, Inc., Madison, Wisconsin, USA
| | | | | | | | - Gerald G Long
- 6 Experimental Pathology Laboratories, Inc., Sterling, Virginia, USA
| | - Emily K Meseck
- 7 Novartis Institutes for Biomedical Research, East Hanover, New Jersey, USA
| | | | | | - Charles E Wood
- 10 U.S. Environmental Protection Agency, Research Triangle Park, North Carolina, USA
| | - Sabine Francke
- 11 Food and Drug Administration, College Park, Maryland, USA
| |
Collapse
|
17
|
Nonaka M, Amakasu K, Saegusa Y, Naota M, Nishimura T, Ogawa K, Nishikawa A. Non-neoplastic lesions found only in the two-year bioassays but not in shorter toxicity studies of rats. Regul Toxicol Pharmacol 2017; 86:199-204. [PMID: 28288808 DOI: 10.1016/j.yrtph.2017.03.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2016] [Revised: 03/02/2017] [Accepted: 03/07/2017] [Indexed: 11/17/2022]
Abstract
International Conference on Harmonisation of Technical Requirements for Registration of Pharmaceuticals for Human Use (ICH) has been conducting a prospective evaluation period to validate the criteria for waiving some carcinogenicity studies in rats. Before the waiving strategy is practiced in ICH, it is crucial to elucidate whether non-neoplastic lesions are found only in 2-year rat carcinogenicity studies. To confirm possible importance of 2-year bioassays for evaluating chronic toxicity but not carcinogenicity, we retrospectively surveyed 59 pharmaceuticals approved by the Ministry of Health, Labour and Welfare (MHLW) from 2007 to 2010 in Japan for non-neoplastic lesions observed in carcinogenicity studies. Non-neoplastic histopathological lesions observed only in 2-year carcinogenicity studies but not in 6-month chronic toxicity studies using rats were compared with clinical adverse drug reactions (ADRs). Thirteen non-neoplastic lesions that may correlate with clinical ADRs were classified into three categories: Category 1, lesions not predictable from other nonclinical data except those from 2-year rat carcinogenicity studies; Category 2, lesions predictable mainly from chronic toxicity studies; Category 3, lesions predictable mainly from pharmacological actions. In the present survey, non-neoplastic lesions only found in 2-year rat carcinogenicity studies were neither significant in terms of frequency and severity nor useful for clinical risk management.
Collapse
Affiliation(s)
- Mizuho Nonaka
- Pharmaceuticals and Medical Devices Agency, 3-3-2 Kasumigaseki, Chiyoda-ku, Tokyo 100-0013, Japan
| | - Kouhei Amakasu
- Pharmaceuticals and Medical Devices Agency, 3-3-2 Kasumigaseki, Chiyoda-ku, Tokyo 100-0013, Japan
| | - Yukie Saegusa
- Pharmaceuticals and Medical Devices Agency, 3-3-2 Kasumigaseki, Chiyoda-ku, Tokyo 100-0013, Japan
| | - Misaki Naota
- Pharmaceuticals and Medical Devices Agency, 3-3-2 Kasumigaseki, Chiyoda-ku, Tokyo 100-0013, Japan
| | - Takuya Nishimura
- Pharmaceuticals and Medical Devices Agency, 3-3-2 Kasumigaseki, Chiyoda-ku, Tokyo 100-0013, Japan
| | - Kumiko Ogawa
- Biological Safety Research Center, National Institute of Health Sciences, 1-18-1 Kamiyoga, Setagaya-ku, Tokyo 158-8501, Japan
| | - Akiyoshi Nishikawa
- Biological Safety Research Center, National Institute of Health Sciences, 1-18-1 Kamiyoga, Setagaya-ku, Tokyo 158-8501, Japan.
| |
Collapse
|
18
|
Bogen KT, Heilman JM. Reassessment of MTBE cancer potency considering modes of action for MTBE and its metabolites. Crit Rev Toxicol 2016; 45 Suppl 1:1-56. [PMID: 26414780 DOI: 10.3109/10408444.2015.1052367] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
A 1999 California state agency cancer potency (CP) evaluation of methyl tert-butyl ether (MTBE) assumed linear risk extrapolations from tumor data were plausible because of limited evidence that MTBE or its metabolites could damage DNA, and based such extrapolations on data from rat gavage and rat and mouse inhalation studies indicating elevated tumor rates in male rat kidney, male rat Leydig interstitial cells, and female rat leukemia/lymphomas. More recent data bearing on MTBE cancer potency include a rodent cancer bioassay of MTBE in drinking water; several new studies of MTBE genotoxicity; several similar evaluations of MTBE metabolites, formaldehyde, and tert-butyl alcohol or TBA; and updated evaluations of carcinogenic mode(s) of action (MOAs) of MTBE and MTBE metabolite's. The lymphoma/leukemia data used in the California assessment were recently declared unreliable by the U.S. Environmental Protection Agency (EPA). Updated characterizations of MTBE CP, and its uncertainty, are currently needed to address a variety of decision goals concerning historical and current MTBE contamination. To this end, an extensive review of data sets bearing on MTBE and metabolite genotoxicity, cytotoxicity, and tumorigenicity was applied to reassess MTBE CP and related uncertainty in view of MOA considerations. Adopting the traditional approach that cytotoxicity-driven cancer MOAs are inoperative at very low, non-cytotoxic dose levels, it was determined that MTBE most likely does not increase cancer risk unless chronic exposures induce target-tissue toxicity, including in sensitive individuals. However, the corresponding expected (or plausible upper bound) CP for MTBE conditional on a hypothetical linear (e.g., genotoxic) MOA was estimated to be ∼2 × 10(-5) (or 0.003) per mg MTBE per kg body weight per day for adults exposed chronically over a lifetime. Based on this conservative estimate of CP, if MTBE is carcinogenic to humans, it is among the weakest 10% of chemical carcinogens evaluated by EPA.
Collapse
|
19
|
Kai T, Tsukamoto Y, Hijiya N, Tokunaga A, Nakada C, Uchida T, Daa T, Iha H, Takahashi M, Nomura T, Sato F, Mimata H, Ikawa M, Seto M, Matsuura K, Moriyama M. Kidney-specific knockout ofSav1in the mouse promotes hyperproliferation of renal tubular epithelium through suppression of the Hippo pathway. J Pathol 2016; 239:97-108. [DOI: 10.1002/path.4706] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2015] [Revised: 01/18/2016] [Accepted: 02/12/2016] [Indexed: 12/31/2022]
Affiliation(s)
- Tomoki Kai
- Department of Molecular Pathology, Faculty of Medicine; Oita University; Yufu Japan
- Department of Urology, Faculty of Medicine; Oita University; Yufu Japan
| | - Yoshiyuki Tsukamoto
- Department of Molecular Pathology, Faculty of Medicine; Oita University; Yufu Japan
| | - Naoki Hijiya
- Department of Molecular Pathology, Faculty of Medicine; Oita University; Yufu Japan
| | - Akinori Tokunaga
- Section of Physiology, Department of Integrative Aging Neuroscience; National Center for Geriatrics and Gerontology; Obu Japan
| | - Chisato Nakada
- Department of Molecular Pathology, Faculty of Medicine; Oita University; Yufu Japan
| | - Tomohisa Uchida
- Department of Molecular Pathology, Faculty of Medicine; Oita University; Yufu Japan
| | - Tsutomu Daa
- Department of Diagnostic Pathology, Faculty of Medicine; Oita University; Yufu Japan
| | - Hidekatsu Iha
- Department of Microbiology, Faculty of Medicine; Oita University; Yufu Japan
| | - Mika Takahashi
- Department of Molecular Pathology, Faculty of Medicine; Oita University; Yufu Japan
- Department of Urology, Faculty of Medicine; Oita University; Yufu Japan
| | - Takeo Nomura
- Department of Urology, Faculty of Medicine; Oita University; Yufu Japan
| | - Fuminori Sato
- Department of Urology, Faculty of Medicine; Oita University; Yufu Japan
| | - Hiromitsu Mimata
- Department of Urology, Faculty of Medicine; Oita University; Yufu Japan
| | - Masahito Ikawa
- Animal Resource Center for Infectious Diseases; Research Institute for Microbial Diseases; Suita Japan
| | - Masao Seto
- Division of Molecular Medicine; Aichi Cancer Institute; Nagoya Japan
| | - Keiko Matsuura
- Department of Molecular Pathology, Faculty of Medicine; Oita University; Yufu Japan
- Department of Biology, Faculty of Medicine; Oita University; Yufu Japan
| | - Masatsugu Moriyama
- Department of Molecular Pathology, Faculty of Medicine; Oita University; Yufu Japan
| |
Collapse
|
20
|
Delaney MA, Ward JM, Walsh TF, Chinnadurai SK, Kerns K, Kinsel MJ, Treuting PM. Initial Case Reports of Cancer in Naked Mole-rats (Heterocephalus glaber). Vet Pathol 2016; 53:691-6. [PMID: 26846576 DOI: 10.1177/0300985816630796] [Citation(s) in RCA: 75] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Naked mole-rats (NMRs;Heterocephalus glaber) are highly adapted, eusocial rodents renowned for their extreme longevity and resistance to cancer. Because cancer has not been formally described in this species, NMRs have been increasingly utilized as an animal model in aging and cancer research. We previously reported the occurrence of several age-related diseases, including putative pre-neoplastic lesions, in zoo-housed NMR colonies. Here, we report for the first time 2 cases of cancer in zoo-housed NMRs. In Case No. 1, we observed a subcutaneous mass in the axillary region of a 22-year-old male NMR, with histologic, immunohistochemical (pancytokeratin positive, rare p63 immunolabeling, and smooth muscle actin negative), and ultrastructural characteristics of an adenocarcinoma possibly of mammary or salivary origin. In Case No. 2, we observed a densely cellular, poorly demarcated gastric mass of polygonal cells arranged in nests with positive immunolabeling for synaptophysin and chromogranin indicative of a neuroendocrine carcinoma in an approximately 20-year-old male NMR. We also include a brief discussion of other proliferative growths and pre-cancerous lesions diagnosed in 1 zoo colony. Although these case reports do not alter the longstanding observation of cancer resistance, they do raise questions about the scope of cancer resistance and the interpretation of biomedical studies in this model. These reports also highlight the benefit of long-term disease investigations in zoo-housed populations to better understand naturally occurring disease processes in species used as models in biomedical research.
Collapse
Affiliation(s)
- M A Delaney
- Department of Comparative Medicine, University of Washington, Seattle, WA, USA
| | - J M Ward
- Global VetPathology, Montgomery Village, MD, USA
| | - T F Walsh
- National Zoological Park, Smithsonian Institution, Washington, DC, USA
| | - S K Chinnadurai
- Chicago Zoological Society and Brookfield Zoo, Brookfield, IL, USA
| | - K Kerns
- National Zoological Park, Smithsonian Institution, Washington, DC, USA
| | - M J Kinsel
- Zoological Pathology Program, University of Illinois, Maywood, IL, USA
| | - P M Treuting
- Department of Comparative Medicine, University of Washington, Seattle, WA, USA
| |
Collapse
|
21
|
Delaney MA, Kinsel MJ, Treuting PM. Renal Pathology in a Nontraditional Aging Model: The Naked Mole-Rat (Heterocephalus glaber). Vet Pathol 2015; 53:493-503. [PMID: 26574557 DOI: 10.1177/0300985815612557] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
The naked mole-rat (NMR; Heterocephalus glaber) is growing in popularity as a model for aging research due to its extreme longevity (up to 30 years), highly adapted physiology, and resistance to cancer, particularly when compared with traditional aging models such as laboratory mice and rats. Despite the NMR's seemingly lengthy health span, several age-related lesions have been documented. During a 15-year retrospective evaluation of a zoo-housed population, histologic changes in the kidneys were reported in 127 of 138 (92%) adult NMRs. Of these, renal tubular mineralization was very common (115 of 127; 90.6%) and found in NMRs without concurrent renal lesions (36 of 127; 28.3%). Many of the other described lesions were considered progressive stages of a single process, generally referred to as chronic nephritis or nephropathy, and diagnosed in 73 of 127 (57.5%), while end-stage renal disease was reported in only 12 (9.4%) NMRs. Renal lesions of these NMRs were comparable to disease entities reported in laboratory rats and certain strains of inbred and noninbred mice. Although many lesions of NMR kidneys were similar to those found in aged laboratory rodents, some common urinary diseases were not represented in the examined colonies. The goal of this study was to describe renal lesions in NMRs from a zoologic setting to familiarize investigators and pathologists with an apparently common and presumably age-related disease in this nontraditional model.
Collapse
Affiliation(s)
- M A Delaney
- Department of Comparative Medicine, University of Washington, Seattle, WA, USA
| | - M J Kinsel
- Zoological Pathology Program, College of Veterinary Medicine, University of Illinois, Maywood, IL, USA
| | - P M Treuting
- Department of Comparative Medicine, University of Washington, Seattle, WA, USA
| |
Collapse
|
22
|
Borghoff S, Poet T, Green S, Davis J, Hughes B, Mensing T, Sarang S, Lynch A, Hard G. Methyl isobutyl ketone exposure-related increases in specific measures of α2u-globulin (α2u) nephropathy in male rats along with in vitro evidence of reversible protein binding. Toxicology 2015; 333:1-13. [DOI: 10.1016/j.tox.2015.02.003] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2014] [Revised: 01/23/2015] [Accepted: 02/10/2015] [Indexed: 11/15/2022]
|
23
|
Nambiar PR, Morton D, Dochterman LW, Houle C, Thomford PJ, Fate G, Bailey SA, Finch GL. Two-year Carcinogenicity Study in Rats with a Nonnucleoside Reverse Transcriptase Inhibitor. Toxicol Pathol 2014; 43:354-65. [DOI: 10.1177/0192623314544381] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Administration of lersivirine, a nonnucleotide reverse transcriptase inhibitor, daily by oral gavage to Sprague-Dawley rats for up to 2 yr was associated with decreased survival, decreased body weights, and an increase in neoplasms and related proliferative lesions in the liver, thyroid, kidney, and urinary bladder. Thyroid follicular adenoma and carcinoma, the associated thyroid follicular hypertrophy/hyperplasia, hepatocellular adenoma/adenocarcinoma, altered cell foci, and hepatocellular hypertrophy were consistent with lersivirine-related induction of hepatic microsomal enzymes. Renal tubular adenoma and renal tubular hyperplasia were attributed to the lersivirine-related exacerbation of chronic progressive nephropathy (CPN), while urinary bladder hyperplasia and transitional cell carcinoma in the renal pelvis and urinary bladder were attributed to urinary calculi. Renal tubular neoplasms associated with increased incidence and severity of CPN, neoplasms of transitional epithelium attributed to crystalluria, and thyroid follicular and hepatocellular neoplasms related to hepatic enzyme induction have low relevance for human risk assessment.
Collapse
|
24
|
Hard GC, Seely JC, Betz LJ. Spontaneous incidence of oncocytic proliferative lesions in control rat kidney. Toxicol Pathol 2014; 42:936-8. [PMID: 24652082 DOI: 10.1177/0192623313502401] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The spontaneous incidence of foci of oncocytic proliferation (oncocytic hyperplasia and oncocytoma) was assessed in a histopathological reevaluation of the kidneys of 2,391 male and female Fischer 344 (F344) groups of control rats from long-term carcinogenicity studies (involving 24 chemicals) that had been conducted by the National Toxicology Program. The overall incidence of oncocytic proliferation was 0.3%, with a male preponderance over females at 0.5% (6/1,236) versus 0.09% (1/1,155), respectively. In males, there appeared to be an association of oncocytic proliferation with advanced spontaneous chronic progressive nephropathy. Oncocytoma or oncocytic hyperplasia appear to be rare lesions in F344 rats, and observations from these carcinogenicity studies suggest that they are slow growing and tend to occur late in a rodent's life span.
Collapse
Affiliation(s)
| | - John Curtis Seely
- Experimental Pathology Laboratories, Inc., Research Triangle Park, North Carolina, USA
| | - Laura J Betz
- SRA International, Inc., Research Triangle Park, North Carolina, USA
| |
Collapse
|
25
|
Maxim LD, Niebo R, Utell MJ, McConnell EE, LaRosa S, Segrave AM. Wollastonite toxicity: an update. Inhal Toxicol 2014; 26:95-112. [DOI: 10.3109/08958378.2013.857372] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
|
26
|
Morton D, Sistare FD, Nambiar PR, Turner OC, Radi Z, Bower N. Regulatory Forum Commentary. Toxicol Pathol 2013; 42:799-806. [DOI: 10.1177/0192623313502130] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
International regulatory and pharmaceutical industry scientists are discussing revision of the International Conference on Harmonisation of Technical Requirements for Registration of Pharmaceuticals for Human Use (ICH) S1 guidance on rodent carcinogenicity assessment of small molecule pharmaceuticals. A weight-of-evidence approach is proposed to determine the need for rodent carcinogenicity studies. For compounds with high human cancer risk, the product may be labeled appropriately without conducting rodent carcinogenicity studies. For compounds with minimal cancer risk, only a 6-month transgenic mouse study (rasH2 mouse or p53+/− mouse) or a 2-year mouse study would be needed. If rodent carcinogenicity testing may add significant value to cancer risk assessment, a 2-year rat study and either a 6-month transgenic mouse or a 2-year mouse study is appropriate. In many cases, therefore, one rodent carcinogenicity study could be sufficient. The rasH2 model predicts neoplastic findings relevant to human cancer risk assessment as well as 2-year rodent models, produces fewer irrelevant neoplastic outcomes, and often will be preferable to a 2-year rodent study. Before revising ICH S1 guidance, a prospective evaluation will be conducted to test the proposed weight-of-evidence approach. This evaluation offers an opportunity for a secondary analysis comparing the value of alternative mouse models and 2-year rodent studies in the proposed ICH S1 weight-of-evidence approach for human cancer risk assessment.
Collapse
Affiliation(s)
| | | | | | - Oliver C. Turner
- Novartis Pharmaceutical Corporation, East Hanover, New Jersey, USA
| | - Zaher Radi
- Pfizer, Inc., Cambridge, Massachusetts, USA
| | - Nancy Bower
- Eisai, Inc., Woodcliff Lake, New Jersey, USA
| |
Collapse
|
27
|
Delaney MA, Nagy L, Kinsel MJ, Treuting PM. Spontaneous histologic lesions of the adult naked mole rat (Heterocephalus glaber): a retrospective survey of lesions in a zoo population. Vet Pathol 2013; 50:607-21. [PMID: 23355517 DOI: 10.1177/0300985812471543] [Citation(s) in RCA: 78] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Naked mole rats (NMRs; Heterocephalus glaber) are highly adapted, subterranean, eusocial rodents from semiarid regions of the eastern horn of Africa and the longest-living rodent known with a maximum life span of up to 30 years. They are a unique model for aging research due to their physiology, extreme longevity, and, when compared to mice and rats, resistance to cancer. Published surveys of disease in NMRs are sparse. Captive colonies in zoological collections provide an opportunity to monitor spontaneous disease over time in a seminatural environment. This retrospective study describes common lesions of a zoo population over a 15-year period during which 138 adult NMRs were submitted for gross and histologic evaluation. Of these, 61 (44.2%) were male, 77 (55.8%) female, 45 (32.6%) died, and 93 (67.4%) were euthanized. The most frequent cause of death or reason for euthanasia was conspecific trauma (bite wounds) and secondary complications. Some common histologic lesions and their prevalence were renal tubular mineralization (82.6%), hepatic hemosiderosis (64.5%), bite wounds (63.8%), chronic progressive nephropathy (52.9%), and calcinosis cutis (10.1%). In sum, 104 (75.4%) NMRs had more than one of the most prevalent histologic lesions. No malignant neoplasms were noted; however, there was a case of renal tubular adenomatous hyperplasia with nuclear atypia and compression that in rats is considered a preneoplastic lesion. This retrospective study confirms the NMR's relative resistance to cancer in spite of development of other degenerative diseases and highlights the utility of zoological databases for baseline pathological data on nontraditional animal models.
Collapse
Affiliation(s)
- M A Delaney
- University of Illinois Zoological Pathology Program, Loyola University Medical Center Building 101, 2160 South First Avenue, Maywood, IL 60153, USA.
| | | | | | | |
Collapse
|
28
|
Hard GC, Banton MI, Bretzlaff RS, Dekant W, Fowles JR, Mallett AK, McGregor DB, Roberts KM, Sielken RL, Valdez-Flores C, Cohen SM. Consideration of rat chronic progressive nephropathy in regulatory evaluations for carcinogenicity. Toxicol Sci 2013; 132:268-75. [PMID: 23104430 PMCID: PMC3595520 DOI: 10.1093/toxsci/kfs305] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2012] [Accepted: 10/09/2012] [Indexed: 12/31/2022] Open
Abstract
Chronic progressive nephropathy (CPN) is a spontaneous renal disease of rats which can be a serious confounder in toxicology studies. It is a progressive disease with known physiological factors that modify disease progression, such as high dietary protein. The weight of evidence supports an absence of a renal counterpart in humans. There is extensive evidence that advanced CPN, particularly end-stage kidney, is a risk factor for development of a background incidence of atypical tubule hyperplasia and renal tubule tumors (RTT). The likely cause underlying this association with tubule neoplasia is the long-term increased tubule cell proliferation that occurs throughout CPN progression. As a variety of chemicals are able to exacerbate CPN, there is a potential for those exacerbating the severity up to and including end-stage kidney to cause a marginal increase in RTT and their precursor lesions. Extensive statistical analysis of National Toxicology Program studies shows a strong correlation between high-grade CPN, especially end-stage CPN, and renal tumor development. CPN as a mode of action (MOA) for rat RTT has received attention from regulatory authorities only recently. In the absence of toxic effects elsewhere, this does not constitute a carcinogenic effect of the chemical but can be addressed through a proposed MOA approach for regulatory purposes to reach a decision that RTT, developing as a result of CPN exacerbation in rats, have no relevance for human risk assessment. Guidelines are proposed for evaluation of exacerbation of CPN and RTT as a valid MOA for a given chemical.
Collapse
Affiliation(s)
- Gordon C Hard
- Private Consultant, 203 Paku Drive, Tairua 3508, New Zealand.
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
29
|
Cesta MF, Hard GC, Boyce JT, Ryan MJ, Chan PC, Sills RC. Complex Histopathologic Response in Rat Kidney to Oral β-myrcene. Toxicol Pathol 2013; 41:1068-77. [DOI: 10.1177/0192623313482057] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Oral gavage studies with β-myrcene in male F344 rats showed a complex renal pathology comprising both alpha2u-globulin (α2u-g) nephropathy, an unusual nephrosis involving the outer stripe of outer medulla (OSOM), and an increased incidence of renal tubule tumors by 2 years. In the 90-day and 2-year studies, respectively, α2u-g nephropathy and linear papillary mineralization were observed in males at the two lower doses but were absent from the high dose. Nephrosis was characterized by dilation of the S3 tubules, nuclear enlargement (including karyomegaly), and luminal pyknotic cells, all in the outermost OSOM. Nephrosis was minimal at the higher doses in the 90-day study, but progressed to a severe grade in males dosed with 1,000 mg/kg for 2 years. Renal tubule tumors developed in treated groups with incidences up to 30% in the 250 and 500 mg/kg male dose groups. Tumors at the lower doses in males may have been associated with α2u-g nephropathy, while those at higher doses in both sexes may have been due to the nephrosis. Because β-myrcene induced a complex spectrum of renal pathology, the α2u-g nephropathy mechanism cannot be the sole mechanism of carcinogenesis in these rats.
Collapse
Affiliation(s)
- Mark F. Cesta
- National Toxicology Program, National Institute of Environmental Health Sciences, Research Triangle Park, North Carolina, USA
| | | | | | | | - Po C. Chan
- National Toxicology Program, National Institute of Environmental Health Sciences, Research Triangle Park, North Carolina, USA
| | - Robert C. Sills
- National Toxicology Program, National Institute of Environmental Health Sciences, Research Triangle Park, North Carolina, USA
| |
Collapse
|
30
|
Perry R, Thompson CA, Earnhardt JN, Wright DJ, Bailey S, Komm B, Cukierski MA. Renal Tumors in Male Rats Following Long-term Administration of Bazedoxifene, a Tissue-selective Estrogen Receptor Modulator. Toxicol Pathol 2013; 41:1001-10. [DOI: 10.1177/0192623313477255] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Bazedoxifene acetate (BZA) is a selective estrogen receptor modulator that is approved in a number of countries for the prevention and/or treatment of osteoporosis in postmenopausal women. To assess carcinogenic potential, BZA was administered ad libitum in the diet to male and female rats for 2 years. The achieved mean dosages of BZA were approximately 1.31 to 56.9 mg/kg/day at dietary concentrations of 0.003% to 0.1%. BZA treatment resulted in a reduction and a delayed onset in total tumor burden in both male and female rats. Survival rates were enhanced due to decreased pituitary and mammary tumors and decreased body weight gain in BZA-treated animals compared with controls. In male rats only, an increase in renal tubular tumors was observed. The greater increase in tumor incidence in male rats given BZA was associated with the increased survival and increased time for development of late onset tumors. These findings are consistent with a non-genotoxic mechanism, unique to male rats, that involves test article–induced corticomedullary mineralization, renal tubular injury, and exacerbation of naturally occurring chronic progressive nephropathy in aged male rats that led to a sequela of proliferative changes and tumor formation.
Collapse
Affiliation(s)
- Rick Perry
- Drug Safety Research & Development, Pfizer, Groton, Connecticut, USA
| | | | - J. Nicole Earnhardt
- Pharmacokinetics, Dynamics, and Metabolism, Pfizer, La Jolla, California, USA
| | - David J. Wright
- Drug Safety Research & Development, Pfizer, Groton, Connecticut, USA
| | - Steven Bailey
- Drug Safety Research & Development, Pfizer, Groton, Connecticut, USA
| | - Barry Komm
- Medical Affairs, Pfizer, Collegeville, Pennsylvania, USA
| | - Mark A. Cukierski
- Drug Safety Research & Development, Pfizer, Groton, Connecticut, USA
| |
Collapse
|
31
|
Keenan KP, Wallig MA, Haschek WM. Nature via nurture: effect of diet on health, obesity, and safety assessment. Toxicol Pathol 2013; 41:190-209. [PMID: 23334694 DOI: 10.1177/0192623312469857] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Food is not only vital for the health and well-being of any living being, but it is a potential source of harmful chemicals, both natural and man-made. Further complicating this is the fact that most nutrients themselves are potentially toxic when consumed in excess. Deficiencies in some of these same nutrients may cause effects that resemble toxicosis or enhance the toxic potential of other nutrients or exogenous chemicals and drugs. This review discusses some of the nutritional and metabolic mechanisms involved and the implications of excess and deficiency in macronutrients and micronutrients in toxicologic pathology. In addition, we review the adverse effects of ad libitum (AL) overfeeding on metabolic, endocrine, renal, and cardiac diseases, and many cancers and the healthful effects of moderate dietary restriction (DR) in modulating obesity and controlling spontaneous and induced diseases of laboratory animals used in toxicology and carcinogenicity studies for human safety assessment.
Collapse
|