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Paz MFCJ, de Alencar MVOB, de Lima RMP, Sobral ALP, do Nascimento GTM, dos Reis CA, Coêlho MDPSDS, do Nascimento MLLB, Gomes Júnior AL, Machado KDC, de Menezes AAPM, de Lima RMT, de Oliveira Filho JWG, Dias ACS, dos Reis AC, da Mata AMOF, Machado SA, Sousa CDDC, da Silva FCC, Islam MT, de Castro e Sousa JM, Melo Cavalcante AADC. Pharmacological Effects and Toxicogenetic Impacts of Omeprazole: Genomic Instability and Cancer. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2020; 2020:3457890. [PMID: 32308801 PMCID: PMC7146093 DOI: 10.1155/2020/3457890] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/15/2019] [Revised: 10/19/2019] [Accepted: 11/21/2019] [Indexed: 12/15/2022]
Abstract
Omeprazole (OME) is commonly used to treat gastrointestinal disorders. However, long-term use of OME can increase the risk of gastric cancer. We aimed to characterize the pharmacological effects of OME and to correlate its adverse effects and toxicogenetic risks to the genomic instability mechanisms and cancer-based on database reports. Thus, a search (till Aug 2019) was made in the PubMed, Scopus, and ScienceDirect with relevant keywords. Based on the study objective, we included 80 clinical reports, forty-six in vitro, and 76 in vivo studies. While controversial, the findings suggest that long-term use of OME (5 to 40 mg/kg) can induce genomic instability. On the other hand, OME-mediated protective effects are well reported and related to proton pump blockade and anti-inflammatory activity through an increase in gastric flow, anti-inflammatory markers (COX-2 and interleukins) and antiapoptotic markers (caspases and BCL-2), glycoprotein expression, and neutrophil infiltration reduction. The reported adverse and toxic effects, especially in clinical studies, were atrophic gastritis, cobalamin deficiencies, homeostasis disorders, polyp development, hepatotoxicity, cytotoxicity, and genotoxicity. This study highlights that OME may induce genomic instability and increase the risk of certain types of cancer. Therefore, adequate precautions should be taken, especially in its long-term therapeutic strategies and self-medication practices.
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Affiliation(s)
- Márcia Fernanda Correia Jardim Paz
- Postgraduate Program in Biotechnology (RENORBIO), Federal University of Piauí, Teresina, PI, Brazil
- Laboratory of Genetic Toxicity, Postgraduate Program in Pharmaceutical Sciences, Federal University of Piauí, Teresina, PI, Brazil
| | | | | | - André Luiz Pinho Sobral
- Laboratory of Genetic Toxicity, Postgraduate Program in Pharmaceutical Sciences, Federal University of Piauí, Teresina, PI, Brazil
- University Hospital, Teresina, PI, Brazil
| | | | | | | | | | - Antonio Luiz Gomes Júnior
- Laboratory of Genetic Toxicity, Postgraduate Program in Pharmaceutical Sciences, Federal University of Piauí, Teresina, PI, Brazil
- University Centre UNINOVAFAPI, Teresina, PI, Brazil
| | | | | | - Rosália Maria Torres de Lima
- Laboratory of Genetic Toxicity, Postgraduate Program in Pharmaceutical Sciences, Federal University of Piauí, Teresina, PI, Brazil
| | | | - Ana Carolina Soares Dias
- Laboratory of Genetics and Molecular Biology, Federal University of Maranhão, São Luís, MA, Brazil
| | - Antonielly Campinho dos Reis
- Laboratory of Genetic Toxicity, Postgraduate Program in Pharmaceutical Sciences, Federal University of Piauí, Teresina, PI, Brazil
| | | | | | | | - Felipe Cavalcanti Carneiro da Silva
- Postgraduate Program in Biotechnology (RENORBIO), Federal University of Piauí, Teresina, PI, Brazil
- Department of Biological Sciences, Federal University of Piauí, Picos, PI, Brazil
| | - Muhammad Torequl Islam
- Department for Management of Science and Technology Development, Ton Duc Thang University, Ho Chi Minh City 700000, Vietnam
- Faculty of Pharmacy, Ton Duc Thang University, Ho Chi Minh City 700000, Vietnam
| | | | - Ana Amélia de Carvalho Melo Cavalcante
- Postgraduate Program in Biotechnology (RENORBIO), Federal University of Piauí, Teresina, PI, Brazil
- Laboratory of Genetic Toxicity, Postgraduate Program in Pharmaceutical Sciences, Federal University of Piauí, Teresina, PI, Brazil
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Cunningham ML. Role of increased DNA replication in the carcinogenic risk of nonmutagenic chemical carcinogens. Mutat Res 1996; 365:59-69. [PMID: 8898989 DOI: 10.1016/s0165-1110(96)90012-3] [Citation(s) in RCA: 45] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
DNA replication is not an error-free process; therefore induction of cell proliferation with the requisite increase in DNA replication may be an important mechanism by which carcinogenesis can be induced by chemicals. Data presented in this overview indicate a positive association between increased cell proliferation and carcinogenesis, and illustrate the value of performing mechanistic studies such as cell proliferation assays in conjunction with short-term tests to further investigate the results of cancer bioassays. Whereas chemically-induced cell proliferation per se may not be sufficient to induce carcinogenesis, it creates a favorable environment for tumor development. There are two types of chemically-induced cell proliferation, mitogenic and cytotoxic, and they have different consequences regarding the mechanism of carcinogenesis of a chemical. Mitogenic chemical such as phenobarbital, oxazepam, and the peroxisome proliferating agents exert a short-term cell proliferative response that may exert its primary effect in carcinogenesis at the promotion stages. It is not clear at what stage(s) cytotoxic agents such as methapyrilene, alpha 2u-globulin inducers or saccharin exert their effects in carcinogenesis. A confounding factor in evaluation of cell proliferation in risk assessments is the production of chemical specific pleiotropic effects that may contribute to the carcinogenicity of a chemical. It is clear that mechanistic studies performed to understand the relationship of sex, species and dose in rodent carcinogenicity assays of chemicals is critical for the extrapolation of such data for human health assessments.
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Affiliation(s)
- M L Cunningham
- Chemistry Branch, National Institute of Environmental Health Sciences, Research Triangle Park, NC 27709, USA.
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Malacarne D, Pesenti R, Paolucci M, Parodi S. Relationship between molecular connectivity and carcinogenic activity: a confirmation with a new software program based on graph theory. ENVIRONMENTAL HEALTH PERSPECTIVES 1993; 101:332-42. [PMID: 8275991 PMCID: PMC1519819 DOI: 10.1289/ehp.93101332] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
For a database of 826 chemicals tested for carcinogenicity, we fragmented the structural formula of the chemicals into all possible contiguous-atom fragments with size between two and eight (nonhydrogen) atoms. The fragmentation was obtained using a new software program based on graph theory. We used 80% of the chemicals as a training set and 20% as a test set. The two sets were obtained by random sorting. From the training sets, an average (8 computer runs with independently sorted chemicals) of 315 different fragments were significantly (p < 0.125) associated with carcinogenicity or lack thereof. Even using this relatively low level of statistical significance, 23% of the molecules of the test sets lacked significant fragments. For 77% of the molecules of the test sets, we used the presence of significant fragments to predict carcinogenicity. The average level of accuracy of the predictions in the test sets was 67.5%. Chemicals containing only positive fragments were predicted with an accuracy of 78.7%. The level of accuracy was around 60% for chemicals characterized by contradictory fragments or only negative fragments. In a parallel manner, we performed eight paired runs in which carcinogenicity was attributed randomly to the molecules of the training sets. The fragments generated by these pseudo-training sets were devoid of any predictivity in the corresponding test sets. Using an independent software program, we confirmed (for the complex biological endpoint of carcinogenicity) the validity of a structure-activity relationship approach of the type proposed by Klopman and Rosenkranz with their CASE program.
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Affiliation(s)
- D Malacarne
- Istituto Nazionale per la Ricerca sul Cancro, Genova, Italy
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Abstract
Besides its use in the treatment of a variety of presumed autoimmune diseases, azathioprine is given as an immunosuppressant to patients who have had renal transplants. Though epidemiological studies have provided "sufficient" evidence of its carcinogenicity in humans, the carcinogenicity tests in rats and mice are considered to be inconclusive because of limitations in the design and results of these tests (IARC, 1981, 1987). Rosenkranz and Klopman (1991) used the CASE program to identify the structural features responsible for its carcinogenicity. They concluded that this genotoxic chemical was a carcinogen due to the presence of the molecular fragment C"-S-C=. The finding was based on the presence of this biophore fragment in five other compounds, namely: 2-amino-5-nitrothiazole, 2-mercaptobenzothiazole, fenthione, 4,4'-thiodianiline and nithiazide. Recently, Ashby (1992) has expressed concern over the validity of their findings. With the aim of contributing to this debate on the mechanism of carcinogenicity of azathioprine, we have analyzed the structural basis of carcinogenicity of azathioprine and the five support compounds using the carcinogenicity predictor of our toxicity prediction program, TOPKAT. The results, more in line with Ashby's concerns, indicate that no molecular fragment involving the S atom is associated with the carcinogenic properties of these molecules. According to the TOPKAT program the carcinogenicity, if any, of azathioprine is due to the NO2 electrophile because its other major structural features are found to be either associated with non-carcinogenicity or do not discriminate carcinogens from non-carcinogens.
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Affiliation(s)
- V K Gombar
- Health Designs, Inc., Rochester, NY 14604
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Ashby J, Paton D. The influence of chemical structure on the extent and sites of carcinogenesis for 522 rodent carcinogens and 55 different human carcinogen exposures. Mutat Res 1993; 286:3-74. [PMID: 7678908 DOI: 10.1016/0027-5107(93)90003-x] [Citation(s) in RCA: 131] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Gold and her colleagues have tabulated the results of rodent bioassays on 522 chemicals and have analysed the data. The present study complements those analyses by providing a perspective from the viewpoint of the chemical structure of the carcinogens. The chemical structure of each of the carcinogens is displayed and the Gold database is represented with the test agents as the primary variable. The carcinogens are gathered into six chemical classes and each chemical is assessed for structural alerts to DNA reactivity. The database is then analysed using an integration of the following parameters: bioassay in rat, mouse or both; structural alert status; chemical class; sites and multiplicity of carcinogenesis, and trans-species carcinogenicity. A series of Figures is presented that enables rapid acquaintance with what represents the core database of rodent carcinogenicity. The several analyses presented combine in endorsing the reality of two broad classes of rodent carcinogen--presumed DNA-reactive and others (putative genotoxic and non-genotoxic carcinogens, but semantics have been largely avoided). Vainio and his colleagues have tabulated 55 situations in which humans have succumbed to chemically induced cancer, and have listed the tissues affected. This database of human carcinogens has been analysed in the present study as done for the rodent carcinogen database, and comparisons made between the two. The predominance of putative genotoxic carcinogens in the human database was confirmed, as was the reality of putative non-genotoxic carcinogenicity in humans. It is concluded that putative genotoxic rodent carcinogenesis can be correlated both with chemical structure and the extent and nature of the induced effect, and that it is of clear relevance to humans. In contrast, it is concluded that putative non-genotoxic rodent carcinogenesis is more closely related to the test species than to the test chemical, and that it is essentially unpredictable in the absence of mechanistic models. In the absence of such models nongenotoxic carcinogenic effects should be extrapolated to humans with caution. Progress in the accurate prediction and extrapolation of rodent carcinogenicity will be helped by a common, if only temporary, enabling acceptance that not all carcinogens are intrinsically genotoxic.
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Affiliation(s)
- J Ashby
- ICI Central Toxicological Laboratory, Macclesfield, Ches., UK
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