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Khateeb S, Taha EFS. Comparative study of the anti-inflammatory activity of etoricoxib and Matcha green tea against acute kidney injury induced by gamma radiation in rats. Int J Radiat Biol 2024; 100:940-964. [PMID: 38647648 DOI: 10.1080/09553002.2024.2338515] [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: 11/01/2023] [Accepted: 03/25/2024] [Indexed: 04/25/2024]
Abstract
PURPOSE The primary objective of this study was to conduct a comparative analysis of the anti-inflammatory activity between Etoricoxib (ETO) and Matcha green tea (MG) in the context of acute kidney injury (AKI) induced by ionizing gamma radiation (IR) in female rats. Furthermore, the potential impact of whole body IR exposure on the intestinal system and serum estradiol levels was investigated. Additionally, it was acknowledged that the ETO and MG treatments might have exerted favorable effects on the intestinal and hormonal responses. MATERIALS AND METHODS Six groups of rats were assigned to different treatments: control, ETO, MG, irradiation (IRR), ETO + IRR, and MG + IRR. The evaluation included measuring the total phenolic and flavonoid contents of ETO and MG, as well as assessing their antioxidant activity, radical scavenging capacity, reducing power, and total antioxidant capacity. Kidney function was assessed through serum creatinine and urea levels. Oxidative stress markers, including superoxide dismutase, glutathione, malondialdehyde, and catalase, were measured to evaluate the antioxidant effects of ETO and MG. The anti-inflammatory potential of the treatments was evaluated by measuring STAT-3 and interleukins (IL-6, IL-23, and IL-17) using an ELISA assay. Prostaglandin E2 receptor (PGE-2) mRNA expression, histopathological examination, and immunohistochemistry for NF-κB inhibitors were performed to investigate the underlying mechanisms in kidney tissue homogenates. Histopathological changes and DNA fragmentation in the intestinal tissues were determined, and the characterization of Matcha green tea was performed using liquid chromatography-mass spectrometry (LC-MS). This allowed for the identification and quantification of various compounds present in Matcha green tea. Furthermore, the study assessed the effect of IR and treatments on estrogen levels in female rats. RESULTS Data showed that both ETO and MG had the potential to mitigate the adverse effects of AKI induced by IR. Notably, MG exhibited greater efficacy in attenuating oxidative stress and inflammation associated with renal injury. These findings revealed and compared the effects of ETO and MG in alleviating AKI caused by IR. MG demonstrated greater anti-inflammatory and antioxidant properties, highlighting its potential as a natural therapeutic agent. CONCLUSIONS These results contribute to the growing evidence supporting the use of MG in managing IR-induced renal complications. Future studies should focus on elucidating the molecular mechanisms and optimizing the application of MG in clinical settings.
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Affiliation(s)
- Sahar Khateeb
- Biochemistry Division, Department of Chemistry, Faculty of Science, Fayoum University, Fayoum, Egypt
- Department of Biochemistry, Faculty of Science, University of Tabuk, Saudi Arabia
| | - Eman F S Taha
- Health Radiation Research Department, National Centre for Radiation Research and Technology, Egyptian Atomic Energy Authority (EAEA), Cairo, Egypt
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Zuckerman JT, Minko IG, Kant M, Jaruga P, Stone MP, Dizdaroglu M, McCullough AK, Lloyd RS. Functional analyses of single nucleotide polymorphic variants of the DNA glycosylase NEIL1 in sub-Saharan African populations. DNA Repair (Amst) 2023; 129:103544. [PMID: 37517321 PMCID: PMC10546947 DOI: 10.1016/j.dnarep.2023.103544] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2023] [Revised: 07/07/2023] [Accepted: 07/18/2023] [Indexed: 08/01/2023]
Abstract
Nei-like glycosylase 1 (NEIL1) is a DNA repair enzyme that initiates the base excision repair (BER) pathway to cleanse the human genome of damage. The substrate specificity of NEIL1 includes several common base modifications formed under oxidative stress conditions, as well as the imidazole ring open adducts that are induced by alkylating agents following initial modification at N7 guanine. An example of the latter is the persistent and mutagenic 8,9-dihydro-8-(2,6-diamino-4-oxo-3,4-dihydropyrimid-5-yl-formamido)-9-hydroxyaflatoxin B1 (AFB1-FapyGua) adduct, resulting from the alkylating agent aflatoxin B1 (AFB1) exo-8-9-epoxide. Naturally occurring single nucleotide polymorphic (SNP) variants of NEIL1 are hypothesized to be associated with an increased risk for development of early-onset hepatocellular carcinoma (HCC), especially in environments with high exposures to aflatoxins and chronic inflammation from viral infections and alcohol consumption. Given that AFB1 exposures and hepatitis B viral (HBV) infections represent a major problem in the developing countries of sub-Saharan Africa, it is pertinent to study SNP NEIL1 variants that are present in this geographic region. In this investigation, we characterized the three most common NEIL1 variants found in this region: P321A, R323G, and I182M. Biochemical analyses were conducted to determine the proficiencies of these variants in initiating the repair of DNA lesions. Our data show that damage recognition and excision activities of P321A and R323G were near that of wild-type (WT) NEIL1 for both thymine glycol (ThyGly) and AFB1-FapyGua. The substrate specificities of these variants with respect to various oxidatively-induced base lesions were also similar to that of WT. In contrast, the I182M variant was unstable, such that it precipitated under a variety of conditions and underwent rapid inactivation at a biologically relevant temperature, with partial stabilization being observed in the presence of undamaged DNA. This study provides insight regarding the potential increased risk for early-onset HCC in human populations carrying the NEIL1 I182M variant.
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Affiliation(s)
- Jamie T Zuckerman
- Oregon Institute of Occupational Health Sciences, Oregon Health & Science University, Portland, OR 97239, United States
| | - Irina G Minko
- Oregon Institute of Occupational Health Sciences, Oregon Health & Science University, Portland, OR 97239, United States
| | - Melis Kant
- Biomolecular Measurement Division, National Institute of Standards and Technology, Gaithersburg, MD 20899, United States
| | - Pawel Jaruga
- Biomolecular Measurement Division, National Institute of Standards and Technology, Gaithersburg, MD 20899, United States
| | - Michael P Stone
- Department of Chemistry, Vanderbilt University, Nashville, TN 37240, United States
| | - Miral Dizdaroglu
- Biomolecular Measurement Division, National Institute of Standards and Technology, Gaithersburg, MD 20899, United States
| | - Amanda K McCullough
- Oregon Institute of Occupational Health Sciences, Oregon Health & Science University, Portland, OR 97239, United States; Department of Molecular and Medical Genetics, Oregon Health & Science University, Portland, OR 97239, United States
| | - R Stephen Lloyd
- Oregon Institute of Occupational Health Sciences, Oregon Health & Science University, Portland, OR 97239, United States; Department of Molecular and Medical Genetics, Oregon Health & Science University, Portland, OR 97239, United States.
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Rasouli H, Nayeri FD, Khodarahmi R. May phytophenolics alleviate aflatoxins-induced health challenges? A holistic insight on current landscape and future prospects. Front Nutr 2022; 9:981984. [PMID: 36386916 PMCID: PMC9649842 DOI: 10.3389/fnut.2022.981984] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2022] [Accepted: 09/26/2022] [Indexed: 12/24/2022] Open
Abstract
The future GCC-connected environmental risk factors expedited the progression of nCDs. Indeed, the emergence of AFs is becoming a global food security concern. AFs are lethal carcinogenic mycotoxins, causing damage to the liver, kidney, and gastrointestinal organs. Long-term exposure to AFs leads to liver cancer. Almost a variety of food commodities, crops, spices, herbaceous materials, nuts, and processed foods can be contaminated with AFs. In this regard, the primary sections of this review aim to cover influencing factors in the occurrence of AFs, the role of AFs in progression of nCDs, links between GCC/nCDs and exposure to AFs, frequency of AFs-based academic investigations, and world distribution of AFs. Next, the current trends in the application of PPs to alleviate AFs toxicity are discussed. Nearly, more than 20,000 published records indexed in scientific databases have been screened to find recent trends on AFs and application of PPs in AFs therapy. Accordingly, shifts in world climate, improper infrastructures for production/storage of food commodities, inconsistency of global polices on AFs permissible concentration in food/feed, and lack of the public awareness are accounting for a considerable proportion of AFs damages. AFs exhibited their toxic effects by triggering the progression of inflammation and oxidative/nitrosative stress, in turn, leading to the onset of nCDs. PPs could decrease AFs-associated oxidative stress, genotoxic, mutagenic, and carcinogenic effects by improving cellular antioxidant balance, regulation of signaling pathways, alleviating inflammatory responses, and modification of gene expression profile in a dose/time-reliant fashion. The administration of PPs alone displayed lower biological properties compared to co-treatment of these metabolites with AFs. This issue might highlight the therapeutic application of PPs than their preventative content. Flavonoids such as quercetin and oxidized tea phenolics, curcumin and resveratrol were the most studied anti-AFs PPs. Our literature review clearly disclosed that considering PPs in antioxidant therapies to alleviate complications of AFs requires improvement in their bioavailability, pharmacokinetics, tissue clearance, and off-target mode of action. Due to the emergencies in the elimination of AFs in food/feedstuffs, further large-scale clinical assessment of PPs to decrease the consequences of AFs is highly required.
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Affiliation(s)
- Hassan Rasouli
- Medical Biology Research Center (MBRC), Kermanshah University of Medical Sciences, Kermanshah, Iran
| | - Fatemeh Dehghan Nayeri
- Department of Biotechnology, Faculty of Agricultural and Natural Sciences, Imam Khomeini International University (IKIU), Qazvin, Iran
| | - Reza Khodarahmi
- Medical Biology Research Center (MBRC), Kermanshah University of Medical Sciences, Kermanshah, Iran
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Chun KS, Raut PK, Kim DH, Surh YJ. Role of chemopreventive phytochemicals in NRF2-mediated redox homeostasis in humans. Free Radic Biol Med 2021; 172:699-715. [PMID: 34214633 DOI: 10.1016/j.freeradbiomed.2021.06.031] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/07/2021] [Revised: 06/14/2021] [Accepted: 06/24/2021] [Indexed: 12/17/2022]
Abstract
While functioning as a second messenger in the intracellular signaling, ROS can cause oxidative stress when produced in excess or not neutralized/eliminated properly. Excessive ROS production is implicated in multi-stage carcinogenesis. Our body is equipped with a defense system to cope with constant oxidative stress caused by the external insults, including redox-cycling chemicals, radiation, and microbial infection as well as endogenously generated ROS. The transcription factor, nuclear transcription factor erythroid 2-related factor 2 (NRF2) is a master switch in the cellular antioxidant signaling and plays a vital role in adaptive survival response to ROS-induced oxidative stress. Although NRF2 is transiently activated when cellular redox balance is challenged, this can be overwhelmed by massive oxidative stress. Therefore, it is necessary to maintain the NRF2-mediated antioxidant defense capacity at an optimal level. This review summarizes the natural NRF2 inducers/activators, especially those present in the plant-based diet, in relation to their cancer chemopreventive potential in humans. The molecular mechanisms underlying their stabilization or activation of NRF2 are also discussed.
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Affiliation(s)
- Kyung-Soo Chun
- College of Pharmacy, Keimyung University, Daegu 42691, South Korea
| | - Pawan Kumar Raut
- College of Pharmacy, Keimyung University, Daegu 42691, South Korea
| | - Do-Hee Kim
- Department of Chemistry, College of Convergence and Integrated Science, Kyonggi University, Suwon, Gyeonggi-do 16227, South Korea
| | - Young-Joon Surh
- Research Institute of Pharmaceutical Sciences, College of Pharmacy, Seoul National University, Seoul 08826, South Korea; Department of Molecular Medicine and Biopharmaceutical Sciences, Graduate School of Convergence Science and Technology, Seoul National University, Seoul 08826, South Korea; Cancer Research Institute, Seoul National University, Seoul 03080, South Korea.
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5
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Habschied K, Kanižai Šarić G, Krstanović V, Mastanjević K. Mycotoxins-Biomonitoring and Human Exposure. Toxins (Basel) 2021; 13:113. [PMID: 33546479 PMCID: PMC7913644 DOI: 10.3390/toxins13020113] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2020] [Revised: 01/23/2021] [Accepted: 01/26/2021] [Indexed: 12/31/2022] Open
Abstract
Mycotoxins are secondary metabolites produced by fungal species that commonly have a toxic effect on human and animal health. Different foodstuff can be contaminated and are considered the major source of human exposure to mycotoxins, but occupational and environmental exposure can also significantly contribute to this problem. This review aims to provide a short overview of the occurrence of toxigenic fungi and regulated mycotoxins in foods and workplaces, following the current literature and data presented in scientific papers. Biomonitoring of mycotoxins in plasma, serum, urine, and blood samples has become a common method for determining the exposure to different mycotoxins. Novel techniques are more and more precise and accurate and are aiming toward the simultaneous determination of multiple mycotoxins in one analysis. Application of liquid chromatography (LC) methodologies, coupled with tandem mass spectrometry (MS/MS) or high-resolution mass spectrometry (HRMS) has become a common and most reliable method for determining the exposure to mycotoxins. Numerous references confirm the importance of mycotoxin biomonitoring to assess the exposure for humans and animals. The objectives of this paper were to review the general approaches to biomonitoring of different mycotoxins and the occurrence of toxigenic fungi and their mycotoxins, using recent literature sources.
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Affiliation(s)
- Kristina Habschied
- Department of Process Engineering, Faculty of Food Technology Osijek, Josip Juraj Strossmayer University of Osijek, 31000 Osijek, Croatia; (V.K.); (K.M.)
| | - Gabriella Kanižai Šarić
- Department of Agroecology and Environment Protection, Faculty of Agrobiotechnical Sciences Osijek, Josip Juraj Strossmayer University of Osijek, 31000 Osijek, Croatia;
| | - Vinko Krstanović
- Department of Process Engineering, Faculty of Food Technology Osijek, Josip Juraj Strossmayer University of Osijek, 31000 Osijek, Croatia; (V.K.); (K.M.)
| | - Krešimir Mastanjević
- Department of Process Engineering, Faculty of Food Technology Osijek, Josip Juraj Strossmayer University of Osijek, 31000 Osijek, Croatia; (V.K.); (K.M.)
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Zhou J, Tang L, Shen CL, Wang JS. Green tea polyphenols boost gut-microbiota-dependent mitochondrial TCA and urea cycles in Sprague-Dawley rats. J Nutr Biochem 2020; 81:108395. [PMID: 32388254 DOI: 10.1016/j.jnutbio.2020.108395] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2019] [Revised: 03/27/2020] [Accepted: 03/30/2020] [Indexed: 12/11/2022]
Abstract
Green tea polyphenols (GTPs) were found to boost mammal energy conversion by modulating gut-microbial community structure, gene orthologs and metabolic pathways. Here we examined the metabolites present in the gut-microbiota-dependent mitochondrial tricarboxylic acid (TCA) cycle and urea cycle using hydrophilic interaction liquid chromatography (HILIC)-heated electrospray ionization (HESI)-tandem liquid chromatogram mass spectrometry (LC-MS). Six groups (n=12) of Sprague-Dawley rats (6-mo, ~250 g) were administered with water containing 0%, 0.5%, and 1.5% GTPs (wt/vol or g/dL). Gut-content samples were collected at 3- and 6-mo. Untargeted metabolomics detected 2177 features, with 91 features demonstrating significant dose- and time-dependencies on the GTPs treatment. Targeted metabolomics analysis revealed remarkable changes of 39 metabolites in the mitochondrial TCA cycle and urea cycle, including argininosuccunic acid (0.9-fold vs control), dihydrouracil (1.14-fold vs control), fumaric acid (1.19-fold vs control), malic acid (2.17-fold vs control), citrulline (1.86-fold vs control), and succinic acid (0.4-fold vs control). The untargeted metabolomics data were mined using bioinformatics approaches, such as analysis of variance-simultaneous component analysis (ASCA), enrichment pathway analysis and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway mapping analysis. The results of 16S rRNA survey, metagenomics analysis, and metabolomics analysis were extrapolated and integrated using databases of Integrated Microbial Genomes and Microbiomes (IMG/M) and KEGG. Our analysis demonstrates that GTPs enhance energy conversion by boosting mitochondrial TCA cycle and urea cycle of gut-microbiota in rats. This metabolic modulation is achieved by enriching many gene orthologs, following the increase of beneficial microbials in families C. Ruminococcaceae, C. Lachnospiraceae and B. Bacteroidaceae.
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Affiliation(s)
- Jun Zhou
- Interdisciplinary Toxicology Program, University of Georgia, Athens, GA, 30602, USA; Department of Environmental Health Science, College of Public Health, University of Georgia, Athens, GA, 30602, USA.
| | - Lili Tang
- Interdisciplinary Toxicology Program, University of Georgia, Athens, GA, 30602, USA; Department of Environmental Health Science, College of Public Health, University of Georgia, Athens, GA, 30602, USA.
| | - Chwan-Li Shen
- Department of Pathology, Texas Technology University, Health Sciences Center, Lubbock, TX 79430, USA.
| | - Jia-Sheng Wang
- Interdisciplinary Toxicology Program, University of Georgia, Athens, GA, 30602, USA; Department of Environmental Health Science, College of Public Health, University of Georgia, Athens, GA, 30602, USA.
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Wang M, Hearon SE, Phillips TD. A high capacity bentonite clay for the sorption of aflatoxins. Food Addit Contam Part A Chem Anal Control Expo Risk Assess 2020; 37:332-341. [PMID: 31790632 PMCID: PMC6989347 DOI: 10.1080/19440049.2019.1662493] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2019] [Accepted: 08/26/2019] [Indexed: 01/28/2023]
Abstract
Previously a calcium bentonite clay (CB) has been shown to tightly bind aflatoxins in vitro, significantly reduce mortality and morbidity in animals, and decrease molecular biomarkers of aflatoxin exposure in humans and animals. Extensive studies have shown that CB is safe for human and animal consumption. In further work, we have investigated a highly active sodium bentonite (SB) clay (SB-E) with enhanced aflatoxin sorption efficacy compared to CB and other clays. Computational models and isothermal analyses were used to characterise toxin/clay surface interactions, predict mechanisms of toxin sorption, and gain insight into: 1) surface capacities and affinities, and 2) thermodynamics and sites of toxin/surface interactions. We have also used a toxin-sensitive living organism (Hydra vulgaris) to confirm the safety and predict the efficacy of SB-E against aflatoxin toxicity. Compared to CB, SB-E had a higher capacity for aflatoxin B1 (AfB1) at pH 2 and 6.5. Results from this work suggest that high capacity clays such as SB-E can be used as effective aflatoxin enterosorbents to decrease short-term exposures in humans and animals when included in food and/or water during extended droughts and outbreaks of aflatoxicosis.
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Affiliation(s)
- Meichen Wang
- Veterinary Integrative Biosciences, College of Veterinary Medicine and
Biomedical Sciences, Texas A&M University, College Station, Texas 77845,
United States
| | - Sara E. Hearon
- Veterinary Integrative Biosciences, College of Veterinary Medicine and
Biomedical Sciences, Texas A&M University, College Station, Texas 77845,
United States
| | - Timothy D Phillips
- Veterinary Integrative Biosciences, College of Veterinary Medicine and
Biomedical Sciences, Texas A&M University, College Station, Texas 77845,
United States
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Wangia RN, Githanga DP, Wang JS, Anzala OA. Aflatoxin exposure in children age 6-12 years: a study protocol of a randomized comparative cross-sectional study in Kenya, East Africa. Pilot Feasibility Stud 2019; 5:141. [PMID: 31798942 PMCID: PMC6884745 DOI: 10.1186/s40814-019-0510-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2019] [Accepted: 10/01/2019] [Indexed: 12/30/2022] Open
Abstract
Background Aflatoxins (AFs) are naturally occurring fungal metabolites produced by the Aspergilla species of fungi. The staple food grain, maize (Zea mays), is highly susceptible to AF contamination. In Kenya, contamination of maize supplies by AFs is a recognized public health problem which has resulted in over 600 human deaths. Human exposure to AFs can occur in utero, via breast milk, through weaning foods, and throughout an individual’s lifetime. Recent epidemiological studies have shown that exposure to AFs in early life through diet is a contributing factor to immune suppression, micronutrient deficiency, possible vaccine interference, and impaired growth in children. However, these results remain inconsistent and inconclusive due to lack of randomized controlled studies. Methods A randomized school-based cross-sectional study was designed to study AF exposure levels and associated health effects in children between ages 6 and 12 years. Participants were recruited from primary schools within Siaya and Makueni Counties of Kenya, East Africa. The Joint Ethics Committee of the University of Nairobi and Kenyatta National Hospital in Kenya approved the research protocol and procedures for the study. Both parental consent and child assent were obtained before enrollment in the study. Parents were requested to provide household grain samples and fill out questionnaires detailing their sociodemographic information, household dietary patterns, farming practices, and knowledge of AF contamination. Blood samples were collected from children participants, and sera were prepared for analysis of AFB1-lysine which is one of the validated biomarkers for AF exposure. Discussion This protocol describes a school-based, cross-sectional study whose objective is to comparatively evaluate the role of AF exposure on adverse health outcomes in children. Specifically, effects of cumulative AF exposure on nutritional status, immune markers, and growth parameters will be assessed. Trial registration This study is not a clinical trial, rather a cross-sectional study aimed at providing baseline data on AF exposures in children who live in presumably high versus low AF exposure regions. Results from the study can be used to design interventions and/or prospective cohort studies aimed at studying adverse health effects associated with cumulative AF exposure through diets. The study reference number is P741/12/2017 and registered with KNH-UoN Ethics and Research Committee.
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Affiliation(s)
- Ruth Nabwire Wangia
- 1Department of Environmental Health Science, College of Public Health, University of Georgia, Athens, GA 30602 USA.,2KAVI Institute of Clinical Research, University of Nairobi, P.O. Box 19676-00202, Nairobi, Kenya
| | - David Peter Githanga
- 3Department of Medical Microbiology, University of Nairobi, P.O. Box 19676-00202, Nairobi, Kenya
| | - Jia-Sheng Wang
- 1Department of Environmental Health Science, College of Public Health, University of Georgia, Athens, GA 30602 USA
| | - Omu Aggrey Anzala
- 2KAVI Institute of Clinical Research, University of Nairobi, P.O. Box 19676-00202, Nairobi, Kenya.,3Department of Medical Microbiology, University of Nairobi, P.O. Box 19676-00202, Nairobi, Kenya
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Benkerroum N. Retrospective and Prospective Look at Aflatoxin Research and Development from a Practical Standpoint. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2019; 16:E3633. [PMID: 31569703 PMCID: PMC6801849 DOI: 10.3390/ijerph16193633] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/17/2019] [Revised: 09/24/2019] [Accepted: 09/26/2019] [Indexed: 12/19/2022]
Abstract
Among the array of structurally and toxicologically diverse mycotoxins, aflatoxins have attracted the most interest of scientific research due to their high toxicity and incidence in foods and feeds. Despite the undeniable progress made in various aspects related to aflatoxins, the ultimate goal consisting of reducing the associated public health risks worldwide is far from being reached due to multiplicity of social, political, economic, geographic, climatic, and development factors. However, a reasonable degree of health protection is attained in industrialized countries owing to their scientific, administrative, and financial capacities allowing them to use high-tech agricultural management systems. Less fortunate situations exist in equatorial and sub-equatorial developing countries mainly practicing traditional agriculture managed by smallholders for subsistence, and where the climate is suitable for mould growth and aflatoxin production. This situation worsens due to climatic change producing conditions increasingly suitable for aflatoxigenic mould growth and toxin production. Accordingly, it is difficult to harmonize the regulatory standards of aflatoxins worldwide, which prevents agri-foods of developing countries from accessing the markets of industrialized countries. To tackle the multi-faceted aflatoxin problem, actions should be taken collectively by the international community involving scientific research, technological and social development, environment protection, awareness promotion, etc. International cooperation should foster technology transfer and exchange of pertinent technical information. This review presents the main historical discoveries leading to our present knowledge on aflatoxins and the challenges that should be addressed presently and in the future at various levels to ensure higher health protection for everybody. In short, it aims to elucidate where we come from and where we should go in terms of aflatoxin research/development.
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Affiliation(s)
- Noreddine Benkerroum
- Department of Food Science and Agricultural Chemistry, Macdonald-Stewart Building, McGill University, Macdonald Campus, 21,111 Lakeshore Road, Sainte-Anne-de-Bellevue, QC H9X 3V9, Canada.
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de Almeida L, Williams R, Soares DM, Nesbitt H, Wright G, Erskine W. Aflatoxin levels in maize and peanut and blood in women and children: The case of Timor-Leste. Sci Rep 2019; 9:13158. [PMID: 31511633 PMCID: PMC6739342 DOI: 10.1038/s41598-019-49584-1] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2019] [Accepted: 08/27/2019] [Indexed: 11/09/2022] Open
Abstract
Aflatoxins are toxic fungal metabolites produced by Aspergillus sp. with carcinogenic properties that are a common food contaminant of many crops including maize and peanuts. In Timor-Leste malnutrition and children's stunting are frequent and maize and peanuts are staple foods. This study aimed to provide information on aflatoxin exposure nationally. The study measured levels of aflatoxin in locally-produced maize and peanuts (296 samples) and of aflatoxin-albumin conjugate in blood samples of women and young children (514 and 620 respectively) across all municipalities. The average concentration of aflatoxin in the grain samples was low with most maize (88%) and peanut (92%) samples - lower than European Commission tolerated aflatoxin level. Although aflatoxin-albumin conjugate was detected in more than 80% of blood samples, the average concentration in children and adults of 0.64 and 0.98 pg mg-1 alb, respectively, is much lower than in other similar rural-based countries. Although low in concentration, blood aflatoxin levels and aflatoxin contamination levels in maize across municipalities were correlated significantly for mothers (R2 = 37%, n = 495) but not for children (R2 = 10%). It is unlikely that the consumption of aflatoxin contaminated grain is a causative factor in the current level of malnutrition and stunting affecting Timor-Leste children.
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Affiliation(s)
- Luis de Almeida
- AI-Com, Ministry of Agriculture and Fisheries, PO Box 221, Comoro-Dili, Timor-Leste.,Centre for Plant Genetics and Breeding, UWA School of Agriculture and Environment & Institute of Agriculture, University of Western Australia, 35 Stirling Highway, Crawley, WA, 6009, Australia
| | - Robert Williams
- AI-Com, Ministry of Agriculture and Fisheries, PO Box 221, Comoro-Dili, Timor-Leste.,Centre for Plant Genetics and Breeding, UWA School of Agriculture and Environment & Institute of Agriculture, University of Western Australia, 35 Stirling Highway, Crawley, WA, 6009, Australia
| | | | - Harry Nesbitt
- Centre for Plant Genetics and Breeding, UWA School of Agriculture and Environment & Institute of Agriculture, University of Western Australia, 35 Stirling Highway, Crawley, WA, 6009, Australia
| | - Graeme Wright
- Peanut Company of Australia (PCA), 133 Haly Street, Kingaroy, Qld, 4610, Australia
| | - William Erskine
- Centre for Plant Genetics and Breeding, UWA School of Agriculture and Environment & Institute of Agriculture, University of Western Australia, 35 Stirling Highway, Crawley, WA, 6009, Australia.
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Wang J, Tang L, Zhou H, Zhou J, Glenn TC, Shen CL, Wang JS. Long-term treatment with green tea polyphenols modifies the gut microbiome of female sprague-dawley rats. J Nutr Biochem 2018; 56:55-64. [PMID: 29454999 PMCID: PMC6022747 DOI: 10.1016/j.jnutbio.2018.01.005] [Citation(s) in RCA: 54] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2017] [Revised: 11/01/2017] [Accepted: 01/10/2018] [Indexed: 12/16/2022]
Abstract
Green tea polyphenols (GTP) have been shown to exert a spectrum of health benefits to animals and humans. It is plausible that the beneficial effects of GTP are a result of its interaction with the gut microbiota. This study evaluated the effect of long-term treatment with GTP on the gut microbiota of experimental rats and the potential linkage between changes of the gut microbiota with the beneficial effects of GTP. Six-month-old Sprague-Dawley rats were randomly allocated into three dosing regimens (0, 0.5%, and 1.5% of GTP) and followed for 6 months. At the end of month 3 or month 6, half of the animals from each group were sacrificed and their colon contents were collected for microbiome analysis using 16S ribosomal RNA and shotgun metagenomic community sequencing. GTP treatment significantly decreased the biodiversity and modified the microbial community in a dose-dependent manner; similar patterns were observed at both sampling times. Multiple operational taxonomic units and phylotypes were modified: the phylotypes Bacteroidetes and Oscillospira, previously linked to the lean phenotype in human and animal studies, were enriched; and Peptostreptococcaceae previously linked to colorectal cancer phenotype was depleted in GTP treated groups in a dose-dependent manner. Several microbial gene orthologs were modified, among which genes related to energy production and conversion were consistently enriched in samples from month 6 in a dose-dependent manner. This study showed that long-term treatment with GTP induced a dose-dependent modification of the gut microbiome in experimental rats, which might be linked to beneficial effects of GTP.
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Affiliation(s)
- Jincheng Wang
- Interdisciplinary Toxicology Program, University of Georgia, Athens, GA 30602, USA; Department of Environmental Health Science, University of Georgia, Athens, GA 30602, USA
| | - Lili Tang
- Interdisciplinary Toxicology Program, University of Georgia, Athens, GA 30602, USA; Department of Environmental Health Science, University of Georgia, Athens, GA 30602, USA
| | - Hongyuan Zhou
- Department of Environmental Health Science, University of Georgia, Athens, GA 30602, USA; School of Food Science and Technology, Jiangnan University, Wuxi 214122, PR China
| | - Jun Zhou
- Interdisciplinary Toxicology Program, University of Georgia, Athens, GA 30602, USA; Department of Environmental Health Science, University of Georgia, Athens, GA 30602, USA
| | - Travis C Glenn
- Interdisciplinary Toxicology Program, University of Georgia, Athens, GA 30602, USA; Department of Environmental Health Science, University of Georgia, Athens, GA 30602, USA
| | - Chwan-Li Shen
- Department of Pathology, School of Medicine, Texas Tech University Health Sciences Center, Lubbock, TX 79430, USA
| | - Jia-Sheng Wang
- Interdisciplinary Toxicology Program, University of Georgia, Athens, GA 30602, USA; Department of Environmental Health Science, University of Georgia, Athens, GA 30602, USA.
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Xue KS, Qian G, Lin S, Su J, Tang L, Gelderblom WC, Riley RT, Phillips TD, Wang JS. Modulation of pre-neoplastic biomarkers induced by sequential aflatoxin B1 and fumonisin B1 exposure in F344 rats treated with UPSN clay. Food Chem Toxicol 2018; 114:316-324. [DOI: 10.1016/j.fct.2018.02.048] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2018] [Revised: 02/07/2018] [Accepted: 02/22/2018] [Indexed: 02/03/2023]
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13
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Ayelign A, Woldegiorgis AZ, Adish A, De Boevre M, Heyndrickx E, De Saeger S. Assessment of aflatoxin exposure among young children in Ethiopia using urinary biomarkers. Food Addit Contam Part A Chem Anal Control Expo Risk Assess 2017; 34:1606-1616. [DOI: 10.1080/19440049.2017.1350290] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Affiliation(s)
- Abebe Ayelign
- Department of Bioanalysis, Laboratory of Food Analysis, Faculty of Pharmaceutical Sciences, Ghent University, Ghent, Belgium
- Center for Food Science and Nutrition, College of Natural Sciences, Addis Ababa University, Addis Ababa, Ethiopia
- Department of Food Science and Postharvest Technology, College of Agriculture and Veterinary Medicine, Jimma University, Jimma, Ethiopia
| | - Ashagrie Zewdu Woldegiorgis
- Center for Food Science and Nutrition, College of Natural Sciences, Addis Ababa University, Addis Ababa, Ethiopia
| | - Abdulaziz Adish
- Micronutrient Initiative (MI), Deputy Regional Director, Addis Ababa, Ethiopia
| | - Marthe De Boevre
- Department of Bioanalysis, Laboratory of Food Analysis, Faculty of Pharmaceutical Sciences, Ghent University, Ghent, Belgium
| | - Ellen Heyndrickx
- Department of Bioanalysis, Laboratory of Food Analysis, Faculty of Pharmaceutical Sciences, Ghent University, Ghent, Belgium
| | - Sarah De Saeger
- Department of Bioanalysis, Laboratory of Food Analysis, Faculty of Pharmaceutical Sciences, Ghent University, Ghent, Belgium
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Ni CX, Gong H, Liu Y, Qi Y, Jiang CL, Zhang JP. Green Tea Consumption and the Risk of Liver Cancer: A Meta-Analysis. Nutr Cancer 2017; 69:211-220. [PMID: 28095030 DOI: 10.1080/01635581.2017.1263754] [Citation(s) in RCA: 42] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Green tea is a commonly consumed beverage in Asia and has been suggested to have anticarcinogenic properties. To date, epidemiological evidence of the effect of green tea consumption on liver cancer risk remains ambiguous. The aim of this meta-analysis is to evaluate the association between green tea consumption and the risk of liver cancer. The summary relative risk for the highest consumption (≥5 cups/day) of green tea on liver cancer incidence compared with nondrinkers was 0.62 (95% confidence interval: 0.49-0.79). We also found a trend that the incidence of liver cancer was reduced with the increasing years of green tea intake (significance at >20 yr). A significant dose-response association was found between green tea drinking and liver cancer risk. The downward trend was most obvious when the consumption of green tea increased up to about 4 cups/day. The results showed that the increasing green tea intake may have a preventive effect against liver cancer.
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Affiliation(s)
- Chen-Xu Ni
- a Department of Pharmacy , Shanghai Tenth People's Hospital, Tongji University School of Medicine , Shanghai , China.,b College of Pharmacy, Second Military Medical University , Shanghai , China
| | - Hong Gong
- c Laboratory of Stress Medicine , Faculty of Psychology and Mental Health, Second Military Medical University , Shanghai , China
| | - Ying Liu
- d Department of Pharmacy , Dongfang Hospital , Shanghai , China
| | - Yang Qi
- b College of Pharmacy, Second Military Medical University , Shanghai , China
| | - Chun-Lei Jiang
- c Laboratory of Stress Medicine , Faculty of Psychology and Mental Health, Second Military Medical University , Shanghai , China
| | - Jun-Ping Zhang
- b College of Pharmacy, Second Military Medical University , Shanghai , China
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15
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Yang CS, Wang H. Cancer Preventive Activities of Tea Catechins. Molecules 2016; 21:E1679. [PMID: 27941682 PMCID: PMC6273642 DOI: 10.3390/molecules21121679] [Citation(s) in RCA: 120] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2016] [Revised: 11/18/2016] [Accepted: 11/24/2016] [Indexed: 02/06/2023] Open
Abstract
Catechins are widely occurring in our diet and beverages. The cancer-preventive activities of catechins have been extensively studied. Of these, (-)-epigallocatechin-3-gallate (EGCG), the principal catechin in green tea, has received the most attention. The inhibitory activities of tea catechins against carcinogenesis and cancer cell growth have been demonstrated in a large number of laboratory studies. Many mechanisms for modulating cancer signaling and metabolic pathways have been proposed based on numerous studies in cell lines with EGCG, the most active tea catechin. Nevertheless, it is not known whether many of these mechanisms indeed contribute to the anti-cancer activities in animals and in humans. Human studies have provided some results for the cancer preventive activities of tea catechins; however, the activities are not strong. This article reviews the cancer preventive activities and mechanisms of action of tea catechins involving their redox activities, biochemical properties and binding to key enzymes or signal transduction proteins. These mechanisms lead to suppression of cell proliferation, increased apoptosis and inhibition of angiogenesis. The relevance of the proposed mechanisms for cancer prevention are assessed in the light of the situation in vivo. The potential and possible problems in the application of tea and tea-derived products for cancer prevention are discussed.
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Affiliation(s)
- Chung S Yang
- Department of Chemical Biology, Ernest Mario School of Pharmacy, Rutgers, The State University of New Jersey, Piscataway, NJ 08854-8020, USA.
| | - Hong Wang
- Department of Chemical Biology, Ernest Mario School of Pharmacy, Rutgers, The State University of New Jersey, Piscataway, NJ 08854-8020, USA.
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Rameshrad M, Razavi BM, Hosseinzadeh H. Protective effects of green tea and its main constituents against natural and chemical toxins: A comprehensive review. Food Chem Toxicol 2016; 100:115-137. [PMID: 27915048 DOI: 10.1016/j.fct.2016.11.035] [Citation(s) in RCA: 53] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2016] [Revised: 11/24/2016] [Accepted: 11/30/2016] [Indexed: 01/26/2023]
Abstract
Toxins are natural or chemical poisonous substances with severe side effects on health. Humans are generally exposed by widespread toxic contaminations via air, soil, water, food, fruits and vegetables. Determining a critical antidote agent with extensive effects on different toxins is an ultimate goal for all toxicologists. Traditional medicine is currently perceived as a safe and natural approach against toxins. In this regard, we focused on the protective effects of green tea (Camellia sinensis) and its main components such as catechin, epicatechin, epicatechin gallate, gallocatechin, epigallocatechin and epigallocatechin gallate as a principal source of antioxidants against both natural and chemical toxins. This literate review demonstrates that protective effects of green tea and its constituents were mainly attributed to their anti-oxidative, radical scavenging, chelating, anti-apoptotic properties and modulating inflammatory responses. Although, some studies reveal they have protective effects by increasing toxin metabolism and neutralizing PLA2, proteases, hyaluronidase and l-amino acid oxidase enzymes.
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Affiliation(s)
- Maryam Rameshrad
- Pharmaceutical Research Center, Department of Pharmacodynamics and Toxicology, School of Pharmacy, Mashhad University of Medical Sciences, Mashhad, Iran.
| | - Bibi Marjan Razavi
- Targeted Drug Delivery Research Center, Department of Pharmacodynamy and Toxicology, School of Pharmacy, Mashhad University of Medical Sciences, Mashhad, Iran.
| | - Hossein Hosseinzadeh
- Pharmaceutical Research Center, Department of Pharmacodynamics and Toxicology, School of Pharmacy, Mashhad University of Medical Sciences, Mashhad, Iran.
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Xue KS, Cai W, Tang L, Wang JS. Aflatoxin B1-lysine adduct in dried blood spot samples of animals and humans. Food Chem Toxicol 2016; 98:210-219. [DOI: 10.1016/j.fct.2016.11.002] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2016] [Revised: 10/30/2016] [Accepted: 11/01/2016] [Indexed: 11/16/2022]
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18
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Schwartzbord J, Severe L, Brown D. Detection of trace aflatoxin M1 in human urine using a commercial ELISA followed by HPLC. Biomarkers 2016; 22:1-4. [PMID: 27319431 DOI: 10.1080/1354750x.2016.1203998] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
Aflatoxin is a liver carcinogen, and rapid, inexpensive methods to detect its urinary biomarkers are needed. We used a commercial enzyme-linked immuno-sorbent assay (ELISA) for aflatoxin M1 in urine (Helica Biosystems) to test 52 Haitian samples. Using this ELISA, we detected traces above the limit of detection (0.2 ng/ml urine) but below the limit of quantitation (0.4 ng/ml) in 14 samples. Liquid chromatography of all 52 Haitian urine samples revealed that only 11 had quantifiable AFM1 (mean: 29.5 pg/ml, standard error: 10.8, range: 2.94-96.5 pg/ml). The Helica ELISA may have detected forms of aflatoxin other than AFM1 in the Haitian samples, or matrix enhancement may have affected results at low AFM1 concentrations. This ELISA may serve as an initial, qualitative indicator of aflatoxin exposure for epidemiological purposes. But this method's utility as a precise and specific indicator of AFM1 concentrations will require additional refinement and validation.
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Affiliation(s)
- Jeremy Schwartzbord
- a Institute of Comparative and Environmental Toxicology, Cornell University , Ithaca , NY , USA
| | | | - Dan Brown
- c Department of Animal Sciences , Cornell University , Ithaca , NY , USA
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Yang CS, Chen JX, Wang H, Lim J. Lessons learned from cancer prevention studies with nutrients and non-nutritive dietary constituents. Mol Nutr Food Res 2016; 60:1239-50. [PMID: 26865098 PMCID: PMC4933959 DOI: 10.1002/mnfr.201500766] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2015] [Revised: 01/15/2016] [Accepted: 01/15/2016] [Indexed: 12/31/2022]
Abstract
Epidemiological studies have observed the association between dietary patterns and the risk of certain types of cancer. Extensive studies have been conducted on the cancer preventive activities of constituents from food and beverages. While laboratory research has shown impressive and promising results, such promising cancer preventive activities have not been demonstrated in many human intervention trials. This article analyzes the major differences between these different types of studies and the limitations of these studies. Animal and cell line studies usually use optimal conditions in order to demonstrate the hypothesized effects, sometimes without considering the human relevance. On the other hand, some clinical trials were designed without a good understanding of the biochemical and pharmacological properties of the agents used. Lessons learned from these studies will be illustrated using vitamin E, β-carotene and selenium as examples for nutrients, and green tea polyphenols as an example for non-nutritive dietary constituents. From the lessons learned, we believe that more interdisciplinary collaboration and integration of laboratory and human studies would effectively advance the field of cancer prevention.
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Affiliation(s)
- Chung S. Yang
- Department of Chemical Biology, Ernest Mario School of Pharmacy, Rutgers, The State University of New Jersey, Piscataway, NJ, USA
| | - Jayson X. Chen
- Department of Chemical Biology, Ernest Mario School of Pharmacy, Rutgers, The State University of New Jersey, Piscataway, NJ, USA
| | - Hong Wang
- Department of Chemical Biology, Ernest Mario School of Pharmacy, Rutgers, The State University of New Jersey, Piscataway, NJ, USA
| | - Justin Lim
- Department of Chemical Biology, Ernest Mario School of Pharmacy, Rutgers, The State University of New Jersey, Piscataway, NJ, USA
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20
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Therapeutic properties of green tea against environmental insults. J Nutr Biochem 2016; 40:1-13. [PMID: 27723473 DOI: 10.1016/j.jnutbio.2016.05.005] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2016] [Revised: 05/04/2016] [Accepted: 05/06/2016] [Indexed: 12/23/2022]
Abstract
Pesticides, smoke, mycotoxins, polychlorinated biphenyls (PCBs), and arsenic are the most common environmental toxins and toxicants to humans. These toxins and toxicants may impact on human health at the molecular (DNA, RNA, or protein), organelle (mitochondria, lysosome, or membranes), cellular (growth inhibition or cell death), tissue, organ, and systemic levels. Formation of reactive radicals, lipid peroxidation, inflammation, genotoxicity, hepatotoxicity, embryotoxicity, neurological alterations, apoptosis, and carcinogenic events are some of the mechanisms mediating the toxic effects of the environmental toxins and toxicants. Green tea, the nonoxidized and nonfermented form of tea that contains several polyphenols, including green tea catechins, exhibits protective effects against these environmental toxins and toxicants in preclinical studies and to a much-limited extent, in clinical trials. The protective effects are collectively mediated by antioxidant, antiinflammatory, antimutagenic, hepatoprotective and neuroprotective, and anticarcinogenic activities. In addition, green tea modulates signaling pathway including NF-κB and ERK pathways, preserves mitochondrial membrane potential, inhibits caspase-3 activity, down-regulates proapoptotic proteins, and induces the phase II detoxifying pathway. The bioavailability and metabolism of green tea and its protective effects against environmental insults induced by pesticides, smoke, mycotoxins, PCBs, and arsenic are reviewed in this paper. Future studies with emphasis on clinical trials should identify biomarkers of green tea intake, examine the mechanisms of action of green tea polyphenols, and investigate potential interactions of green tea with other toxicant-modulating dietary factors.
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Jager AV, Tonin FG, Baptista GZ, Souto PC, Oliveira CA. Assessment of aflatoxin exposure using serum and urinary biomarkers in São Paulo, Brazil: A pilot study. Int J Hyg Environ Health 2016; 219:294-300. [DOI: 10.1016/j.ijheh.2015.12.003] [Citation(s) in RCA: 43] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2015] [Revised: 11/27/2015] [Accepted: 12/14/2015] [Indexed: 10/22/2022]
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Mitigation of Fumonisin Biomarkers by Green Tea Polyphenols in a High-Risk Population of Hepatocellular Carcinoma. Sci Rep 2015; 5:17545. [PMID: 26626148 PMCID: PMC4667183 DOI: 10.1038/srep17545] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2015] [Accepted: 11/03/2015] [Indexed: 11/21/2022] Open
Abstract
Green tea polyphenols (GTP) are highly effective in inhibiting a variety of tumorigenic effects induced by carcinogens. In this study we assessed GTP mitigation on biomarkers of fumonisin B1 (FB1), a class 2B carcinogen, in blood and urine samples collected from an intervention trial. A total of 124 exposed people were recruited and randomly assigned to low-dose (GTP 500 mg, n = 42), high-dose (GTP 1,000 mg, n = 41) or placebo (n = 41) for 3 months. After one-month of intervention, urinary FB1 was significantly decreased in high-dose group compared to that of placebo group (p = 0.045), with reduction rates of 18.95% in the low-dose group and 33.62% in the high-dose group. After three-month intervention, urinary FB1 showed significant decrease in both low-dose (p = 0.016) and the high-dose (p = 0.0005) groups compared to that of both placebo group and baseline levels, with reduction rates of 40.18% in the low-dose group and 52.6% in the high-dose group. GTP treatment also significantly reduced urinary excretion of sphinganine (Sa), sphingosine (So), and Sa/So ratio, but had no effect on serum Sa, So, and Sa/So ratio. Analysis with mixed-effect model revealed significant interactions between time and treatment effects of GTP on both urinary free FB1 levels and Sa/So ratios.
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Effect of supplementation of fermented milk drink containing probiotic Lactobacillus casei Shirota on the concentrations of aflatoxin biomarkers among employees of Universiti Putra Malaysia: a randomised, double-blind, cross-over, placebo-controlled study. Br J Nutr 2015; 115:39-54. [PMID: 26490018 DOI: 10.1017/s0007114515004109] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Human exposure to aflatoxin is through the diet, and probiotics are able to bind aflatoxin and prevent its absorption in the small intestine. This study aimed to determine the effectiveness of a fermented milk drink containing Lactobacillus casei Shirota (LcS) (probiotic drink) to prevent aflatoxin absorption and reduce serum aflatoxin B1-lysine adduct (AFB1-lys) and urinary aflatoxin M1 concentrations. The present study was a randomised, double-blind, cross-over, placebo-controlled study with two 4-week intervention phases. In all, seventy-one subjects recruited from the screening stage were divided into two groups--the Yellow group and the Blue group. In the 1st phase, one group received probiotic drinks twice a day and the other group received placebo drinks. Blood and urine samples were collected at baseline, 2nd and 4th week of the intervention. After a 2-week wash-out period, the treatments were switched between the groups, and blood and urine samples were collected at the 6th, 8th and 10th week (2nd phase) of the intervention. No significant differences in aflatoxin biomarker concentrations were observed during the intervention. A within-group analysis was further carried out. Aflatoxin biomarker concentrations were not significantly different in the Yellow group. Nevertheless, ANOVA for repeated measurements indicated that AFB1-lys concentrations were significantly different (P=0·035) with the probiotic intervention in the Blue group. The 2nd week AFB1-lys concentrations (5·14 (SD 2·15) pg/mg albumin (ALB)) were significantly reduced (P=0·048) compared with the baseline (6·24 (SD 3·42) pg/mg ALB). Besides, the 4th week AFB1-lys concentrations were significantly lower (P<0·05) with probiotic supplementation than with the placebo. Based on these findings, a longer intervention study is warranted to investigate the effects of continuous LcS consumption to prevent dietary aflatoxin exposure.
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Ali N, Hossain K, Blaszkewicz M, Rahman M, Mohanto NC, Alim A, Degen GH. Occurrence of aflatoxin M1 in urines from rural and urban adult cohorts in Bangladesh. Arch Toxicol 2015; 90:1749-55. [DOI: 10.1007/s00204-015-1601-y] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2015] [Accepted: 09/10/2015] [Indexed: 02/04/2023]
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Kang MS, Nkurunziza P, Muwanika R, Qian G, Tang L, Song X, Xue K, Nkwata A, Ssempebwa J, Lutalo T, Asiki G, Serwadda D, Seeley J, Kaleebu P, Nalugoda F, Newton R, William JH, Wang JS. Longitudinal evaluation of aflatoxin exposure in two cohorts in south-western Uganda. Food Addit Contam Part A Chem Anal Control Expo Risk Assess 2015. [PMID: 26208708 DOI: 10.1080/19440049.2015.1048749] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
Aflatoxins (AF) are a group of mycotoxins. AF exposure causes acute and chronic adverse health effects such as aflatoxicosis and hepatocellular carcinoma in human populations, especially in the developing world. In this study, AF exposure was evaluated using archived serum samples from human immunodeficiency virus (HIV)-seronegative participants from two cohort studies in south-western Uganda. AFB1-lysine (AFB-Lys) adduct levels were determined via HPLC fluorescence in a total of 713 serum samples from the General Population Cohort (GPC), covering eight time periods between 1989 and 2010. Overall, 90% (642/713) of the samples were positive for AFB-Lys and the median level was 1.58 pg mg(-1) albumin (range = 0.40-168 pg mg(-1) albumin). AFB-Lys adduct levels were also measured in a total of 374 serum samples from the Rakai Community Cohort Study (RCCS), across four time periods between 1999 and 2003. The averaged detection rate was 92.5% (346/374) and the median level was 1.18 pg mg(-1) albumin (range = 0.40-122.5 pg mg(-1) albumin). In the GPC study there were no statistically significant differences between demographic parameters, such as age, sex and level of education, and levels of serum AFB-Lys adduct. In the RCCS study, longitudinal analysis using generalised estimating equations revealed significant differences between the adduct levels and residential areas (p = 0.05) and occupations (p = 0.02). This study indicates that AF exposure in people in two populations in south-western Uganda is persistent and has not significantly changed over time. Data from one study, but not the other, indicated that agriculture workers and rural area residents had more AF exposure than those non-agricultural workers and non-rural area residents. These results suggest the need for further study of AF-induced human adverse health effects, especially the predominant diseases in the region.
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Affiliation(s)
- Min-Su Kang
- a College of Public Health and Peanut CRSP , University of Georgia , Athens , GA , USA
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Biomarkers of Dietary Polyphenols in Cancer Studies: Current Evidence and Beyond. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2015; 2015:732302. [PMID: 26180594 PMCID: PMC4477246 DOI: 10.1155/2015/732302] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Download PDF] [Subscribe] [Scholar Register] [Received: 09/26/2014] [Accepted: 01/06/2015] [Indexed: 12/13/2022]
Abstract
Polyphenols, commonly contained in fruits and vegetables, have long been associated with a protective role against multiple diseases and adverse health effects. Generally, in vitro and animal experiments have provided strong positive evidence, whereas evidence from in vivo and human epidemiological studies is not strong enough. Most epidemiological studies to date use food frequency questionnaire based dietary intake estimations, which inevitably incur imprecision. Biomarkers of polyphenol have the potential to complement and enhance current studies. This review performed a literature search of all epidemiological studies or controlled clinical/intervention trials which employed biomarkers of exposure for polyphenols to help assess their anticarcinogenic role, using studies on green tea polyphenols as a study model. Currently, studies on this topic are still limited; breast cancer and prostate cancer were the only widely studied cancer types. Isoflavone is the only widely studied polyphenol. In addition to associations between polyphenols and cancer risks, factors such as host genetic susceptibility, epigenetic modification, and gut microbiome patterns may also impact on the protective roles of polyphenols. More evidence should be collected by utilizing biomarkers of exposure for polyphenols in future epidemiological studies before a clear conclusion can be made.
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Influence of green tea extract on oxidative damage and apoptosis induced by deltamethrin in rat brain. Neurotoxicol Teratol 2015; 50:23-31. [PMID: 26013673 DOI: 10.1016/j.ntt.2015.05.005] [Citation(s) in RCA: 56] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2014] [Revised: 05/13/2015] [Accepted: 05/13/2015] [Indexed: 01/14/2023]
Abstract
In the present study, we investigated the protective effect of an aqueous extract of green tea leaves (GTE) against neurotoxicity and oxidative damage induced by deltamethrin (DM) in male rats. Four different groups of rats were used: the 1st group was the vehicle treated control group, the 2nd group received DM (0.6 mg/kg BW), the 3rd group received DM plus GTE, and the 4th received GTE alone (25 mg/kg BW). The brain tissues were collected at the end of the experimental regimen for subsequent investigation. Rats that were given DM had a highly significant elevation in MDA content, nitric oxide concentration, DNA fragmentation and expression level of apoptotic genes, TP53 and COX2. Additionally, a significant reduction in the total antioxidant capacity in the second group was detected. The findings for the 3rd group highlight the efficacy of GTE as a neuro-protectant in DM-induced neurotoxicity through improving the oxidative status and DNA fragmentation as well as suppressing the expression of the TP53 and COX2 genes. In conclusion, GTE, at a concentration of 25mg/kg/day, protected against DM-induced neurotoxicity through its antioxidant and antiapoptotic influence; therefore, it can be used as a protective natural product against DM-induced neurotoxicity.
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Simultaneous quantification of multiple urinary naphthalene metabolites by liquid chromatography tandem mass spectrometry. PLoS One 2015; 10:e0121937. [PMID: 25853821 PMCID: PMC4390350 DOI: 10.1371/journal.pone.0121937] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2014] [Accepted: 02/06/2015] [Indexed: 11/23/2022] Open
Abstract
Naphthalene is an environmental toxicant to which humans are exposed. Naphthalene causes dose-dependent cytotoxicity to murine airway epithelial cells but a link between exposure and human pulmonary disease has not been established. Naphthalene toxicity in rodents depends on P450 metabolism. Subsequent biotransformation results in urinary elimination of several conjugated metabolites. Glucuronide and sulfate conjugates of naphthols have been used as markers of naphthalene exposure but, as the current studies demonstrate, these assays provide a limited view of the range of metabolites generated from the parent hydrocarbon. Here, we present a liquid chromatography tandem mass spectrometry method for measurement of the glucuronide and sulfate conjugates of 1-naphthol as well as the mercapturic acids and N-acetyl glutathione conjugates from naphthalene epoxide. Standard curves were linear over 2 log orders. On column detection limits varied from 0.91 to 3.4 ng; limits of quantitation from 1.8 to 6.4 ng. The accuracy of measurement of spiked urine standards was -13.1 to + 5.2% of target and intra-day and inter-day variability averaged 7.2 (± 4.5) and 6.8 (± 5.0) %, respectively. Application of the method to urine collected from mice exposed to naphthalene at 15 ppm (4 hrs) showed that glutathione-derived metabolites accounted for 60-70% of the total measured metabolites and sulfate and glucuronide conjugates were eliminated in equal amounts. The method is robust and directly measures several major naphthalene metabolites including those derived from glutathione conjugation of naphthalene epoxide. The assays do not require enzymatic deconjugation, extraction or derivatization thus simplifying sample work up.
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Sass DC, Jager AV, Tonin FG, Rosim RE, Constantino MG, Oliveira CAF. Synthesis and purification of the aflatoxin B1-lysine adduct. TOXIN REV 2014. [DOI: 10.3109/15569543.2014.994132] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
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Dietary pretreatment with green tea polyphenol, (-)-epigallocatechin-3-gallate reduces the bioavailability and hepatotoxicity of subsequent oral bolus doses of (-)-epigallocatechin-3-gallate. Food Chem Toxicol 2014; 76:103-8. [PMID: 25528115 DOI: 10.1016/j.fct.2014.12.009] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2014] [Revised: 12/12/2014] [Accepted: 12/14/2014] [Indexed: 01/18/2023]
Abstract
Human case-studies have reported an association between green tea-based dietary supplements and hepatotoxicity. Studies have demonstrated the hepatotoxicity of high-dose oral bolus dosing with the tea polyphenol (-)-epigallocatechin-3-gallate (EGCG) in mice and dogs. We examined the effect of pretreatment with dietary EGCG on the hepatotoxicity and bioavailability of acute oral bolus dosing with EGCG in CF-1 mice. EGCG (750 mg/kg, i.g., once daily for 3 days) increased plasma alanine aminotransferase by 80-fold, decreased both reduced (by 59%) and total (by 33%) hepatic glutathione, and increased hepatic levels of phosphorylated histone 2AX. Pretreatment with dietary EGCG (3.2 mg/g diet) for 2 weeks mitigated hepatotoxicity. Acute oral EGCG also decreased mRNA expression of glutathione reductase. Dietary pretreatment prevented these decreased and increased glutathione peroxidase (Gpx)2, Gpx3, Gpx5, and Gpx7 expression. We found that dietary EGCG reduced the plasma (57% reduction) and hepatic (71% reduction) EGCG exposure following oral bolus dosing compared to mice that were not pre-treated. Overall, it appears that EGCG can modulate its own bioavailability and that dietary treatment may reduce the toxic potential of acute high oral bolus doses of EGCG. These data may partly explain the observed variation in hepatotoxic response to green tea-containing dietary supplements.
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Determination of urinary biomarkers for assessment of short-term human exposure to aflatoxins in São Paulo, Brazil. Toxins (Basel) 2014; 6:1996-2007. [PMID: 25007123 PMCID: PMC4113737 DOI: 10.3390/toxins6071996] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2014] [Revised: 06/18/2014] [Accepted: 06/26/2014] [Indexed: 11/16/2022] Open
Abstract
In the present study, a longitudinal assessment was carried out to evaluate the short-term human exposure to aflatoxins in Pirassununga region, São Paulo, Brazil, by determination of urinary aflatoxins by a liquid chromatography coupled to mass sprectrometry (UPLC-MS/MS) method. Sixteen volunteers with ages ranging from 14 to 55 years old were instructed to collect the early morning first urine four times every three months, from June 2011 to March 2012, totaling 64 samples. Aflatoxin M1 (AFM1) was found in 39 samples (61%) at levels ranging from 0.19 to 12.7 pg·mg-1 creatinine (mean: 1.2 ± 2.0 pg·mg-1 creatinine). Residues of aflatoxins B1, B2, G1, G2 and aflatoxicol were not identified in any urine sample. No significant difference was found among the AFM1 mean levels in urine samples collected in the four sampling periods. The levels of AFM1 found in urine samples indicate a low short-term exposure of the population studied to aflatoxins through the diet, although further investigations are needed to assess other long-term biomarkers of exposure to AFB1.
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Lai H, Mo X, Yang Y, He K, Xiao J, Liu C, Chen J, Lin Y. Association between aflatoxin B1 occupational airway exposure and risk of hepatocellular carcinoma: a case-control study. Tumour Biol 2014. [PMID: 24961349 DOI: 10.1007/-s13277-014-2231-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
The aim of this study was to determine the airway exposure of sugar and papermaking factory workers to aflatoxin B1 (AFB1) and to explore the potential association between AFB1 airway exposure and the risk of hepatocellular carcinoma (HCC) in a case-control study. Dust samples were collected from the sugarcane bagasse warehouse, and presser and paper production workshops. Blood samples were collected from 181 workshop employees and 203 controls who worked outside the workshop. AFB1 albumin adducts were detected using a double antibody sandwich enzyme-linked immunosorbent assay (ELISA). To explore the association between AFB1 airway exposure and the risk of HCC, the medical records of 68 HCC patients who worked in a sugar and papermaking factory between January 1994 and December 2013 were analyzed. A questionnaire was used to collect information from 150 healthy controls who worked for the same company and lived near the factory. AFB1 was detected in the dust samples, but could not be detected in any of the rice samples. An analysis of serum samples revealed serum AFB1 albumin adducts in 102 (56.35 %) of the study participants. However, in the control group, only 12 (5.9 %) individuals had detectable levels of AFB1 albumin adducts. Those with airway exposure to Aspergillus flavus-contaminated dust had an elevated risk of HCC compared to those without exposure (odds ratio, 5.24; 95 % confidence interval, 2.77-9.88; P = 0.00). The findings of this study indicate that occupational AFB1 airway exposure might be associated with the risk of AFB1-related HCC among the population that was used in this study. Intervention programs aimed at reducing exposure to inhalational AFB1 are needed urgently. Additional suitably designed, multicenter, prospective studies using large samples are needed to further confirm the results.
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Affiliation(s)
- Hao Lai
- Department of Gastrointestinal Surgery, Affiliated Cancer Hospital of Guangxi Medical University, 71 Hedi Road, Nanning, 530021, Guangxi Autonomous Region, China
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Lai H, Mo X, Yang Y, He K, Xiao J, Liu C, Chen J, Lin Y. Association between aflatoxin B1 occupational airway exposure and risk of hepatocellular carcinoma: a case-control study. Tumour Biol 2014; 35:9577-84. [PMID: 24961349 PMCID: PMC4213372 DOI: 10.1007/s13277-014-2231-3] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2014] [Accepted: 06/11/2014] [Indexed: 12/13/2022] Open
Abstract
The aim of this study was to determine the airway exposure of sugar and papermaking factory workers to aflatoxin B1 (AFB1) and to explore the potential association between AFB1 airway exposure and the risk of hepatocellular carcinoma (HCC) in a case-control study. Dust samples were collected from the sugarcane bagasse warehouse, and presser and paper production workshops. Blood samples were collected from 181 workshop employees and 203 controls who worked outside the workshop. AFB1 albumin adducts were detected using a double antibody sandwich enzyme-linked immunosorbent assay (ELISA). To explore the association between AFB1 airway exposure and the risk of HCC, the medical records of 68 HCC patients who worked in a sugar and papermaking factory between January 1994 and December 2013 were analyzed. A questionnaire was used to collect information from 150 healthy controls who worked for the same company and lived near the factory. AFB1 was detected in the dust samples, but could not be detected in any of the rice samples. An analysis of serum samples revealed serum AFB1 albumin adducts in 102 (56.35 %) of the study participants. However, in the control group, only 12 (5.9 %) individuals had detectable levels of AFB1 albumin adducts. Those with airway exposure to Aspergillus flavus-contaminated dust had an elevated risk of HCC compared to those without exposure (odds ratio, 5.24; 95 % confidence interval, 2.77–9.88; P = 0.00). The findings of this study indicate that occupational AFB1 airway exposure might be associated with the risk of AFB1-related HCC among the population that was used in this study. Intervention programs aimed at reducing exposure to inhalational AFB1 are needed urgently. Additional suitably designed, multicenter, prospective studies using large samples are needed to further confirm the results.
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Affiliation(s)
- Hao Lai
- Department of Gastrointestinal Surgery, Affiliated Cancer Hospital of Guangxi Medical University, 71 Hedi Road, Nanning, 530021 Guangxi Autonomous Region China
| | - Xianwei Mo
- Department of Gastrointestinal Surgery, Affiliated Cancer Hospital of Guangxi Medical University, 71 Hedi Road, Nanning, 530021 Guangxi Autonomous Region China
| | - Yang Yang
- Department of Gastrointestinal Surgery, Affiliated Cancer Hospital of Guangxi Medical University, 71 Hedi Road, Nanning, 530021 Guangxi Autonomous Region China
| | - Ke He
- Department of Head and Neck Surgery, Affiliated Cancer Hospital of Guangxi Medical University, Nanning, 530021 Guangxi Autonomous Region China
| | - Jun Xiao
- Department of Gastrointestinal Surgery, Affiliated Cancer Hospital of Guangxi Medical University, 71 Hedi Road, Nanning, 530021 Guangxi Autonomous Region China
| | - Chao Liu
- Department of Gastrointestinal Surgery, Affiliated Cancer Hospital of Guangxi Medical University, 71 Hedi Road, Nanning, 530021 Guangxi Autonomous Region China
| | - Jiansi Chen
- Department of Gastrointestinal Surgery, Affiliated Cancer Hospital of Guangxi Medical University, 71 Hedi Road, Nanning, 530021 Guangxi Autonomous Region China
| | - Yuan Lin
- Department of Gastrointestinal Surgery, Affiliated Cancer Hospital of Guangxi Medical University, 71 Hedi Road, Nanning, 530021 Guangxi Autonomous Region China
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Mycotoxins in a changing global environment--a review. Food Chem Toxicol 2014; 69:220-30. [PMID: 24769018 DOI: 10.1016/j.fct.2014.04.025] [Citation(s) in RCA: 207] [Impact Index Per Article: 20.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2013] [Revised: 04/10/2014] [Accepted: 04/14/2014] [Indexed: 01/01/2023]
Abstract
Mycotoxins are toxic metabolites produced by fungal species that commonly contaminate staple foods and feeds. They represent an unavoidable problem due to their presence in globally consumed cereals such as rice, maize and wheat. Most mycotoxins are immunosuppressive agents and some are carcinogens, hepatotoxins, nephrotoxins, and neurotoxins. Worldwide trends envision a stricter control of mycotoxins, however, the changing global environment may not be the ideal setting to control and reduce the exposure to these toxins. Although new technologies allow us to inspect the multi-mycotoxin presence in foods, new sources of exposure, gaps in knowledge of mycotoxins interactions, appearance of "emergent" mycotoxins and elucidation of consequent health effects can complicate their control even more. While humans are adapting to cope with environmental changes, such as food scarcity, decreased food quality, mycotoxin regulations, crop production and seasonality, and other climate related modifications, fungal species are also adapting and increased cases of mycotoxin adverse health effects are likely to occur in the future. To guarantee access to quality food for all, we need a way to balance global mycotoxin standards with the realistic feasibility of reaching them, considering limitations of producers and designing strategies to reduce mycotoxin exposure based on sound research.
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Abstract
The inhibitory activities of tea catechins against carcinogenesis and cancer cell growth have been demonstrated in a large number of laboratory studies. Many mechanisms for modulating cancer signaling and metabolic pathways have been proposed based on numerous studies in cell lines with (-)-epigallocatechin-3-gallate, the most abundant and active tea catechin. Nevertheless, the molecular basis for the proposed mechanisms and whether these mechanisms indeed contribute to the anticancer activities in vivo are not clearly known. This chapter reviews the basic redox properties of tea catechins, their binding to key enzymes and signal transduction proteins, and other mechanisms that lead to suppression of cell proliferation, increased apoptosis, and inhibition of angiogenesis. More weight is put on studies in vivo over experiments in vitro. It also discusses key issues involved in extrapolating results from cell line studies to mechanistic insights in vivo.
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Affiliation(s)
- Chung S Yang
- Department of Chemical Biology, Ernest Mario School of Pharmacy, Rutgers, The State University of New Jersey, Piscataway, New Jersey, USA; International Joint Research Laboratory of Tea Chemistry and Health Effects, Anhui Agricultural University, Hefei, PR China.
| | - Hong Wang
- Department of Chemical Biology, Ernest Mario School of Pharmacy, Rutgers, The State University of New Jersey, Piscataway, New Jersey, USA
| | - Jayson X Chen
- Department of Chemical Biology, Ernest Mario School of Pharmacy, Rutgers, The State University of New Jersey, Piscataway, New Jersey, USA
| | - Jinsong Zhang
- International Joint Research Laboratory of Tea Chemistry and Health Effects, Anhui Agricultural University, Hefei, PR China
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Turner PC. The molecular epidemiology of chronic aflatoxin driven impaired child growth. SCIENTIFICA 2013; 2013:152879. [PMID: 24455429 PMCID: PMC3881689 DOI: 10.1155/2013/152879] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/18/2013] [Accepted: 10/27/2013] [Indexed: 06/03/2023]
Abstract
Aflatoxins are toxic secondary fungal metabolites that contaminate dietary staples in tropical regions; chronic high levels of exposure are common for many of the poorest populations. Observations in animals indicate that growth and/or food utilization are adversely affected by aflatoxins. This review highlights the development of validated exposure biomarkers and their use here to assess the role of aflatoxins in early life growth retardation. Aflatoxin exposure occurs in utero and continues in early infancy as weaning foods are introduced. Using aflatoxin-albumin exposure biomarkers, five major studies clearly demonstrate strong dose response relationships between exposure in utero and/or early infancy and growth retardation, identified by reduced birth weight and/or low HAZ and WAZ scores. The epidemiological studies include cross-sectional and longitudinal surveys, though aflatoxin reduction intervention studies are now required to further support these data and guide sustainable options to reduce the burden of exposure. The use of aflatoxin exposure biomarkers was essential in understanding the observational data reviewed and will likely be a critical monitor of the effectiveness of interventions to restrict aflatoxin exposure. Given that an estimated 4.5 billion individuals live in regions at risk of dietary contamination the public health concern cannot be over stated.
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Affiliation(s)
- Paul Craig Turner
- Maryland Institute for Applied Environmental Health, School of Public Health, University of Maryland, College Park, MD 20742, USA
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Yuan JM. Cancer prevention by green tea: evidence from epidemiologic studies. Am J Clin Nutr 2013; 98:1676S-1681S. [PMID: 24172305 PMCID: PMC3831544 DOI: 10.3945/ajcn.113.058271] [Citation(s) in RCA: 73] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
In contrast to the consistent results of an inhibitory effect of green tea extracts and tea polyphenols on the development and growth of carcinogen-induced tumors in experimental animal models, results from human studies are mixed. Both observational and intervention studies have provided evidence in support of a protective role of green tea intake in the development of oral-digestive tract cancer or an inhibitory role of oral supplementation of green tea extract on a precancerous lesion of oral cavity. Evidence in support of green tea intake against the development of liver cancer risk is limited and inconsistent. An inverse association between green tea intake and lung cancer risk has been observed among never smokers but not among smokers. Although observational studies do not support a beneficial role of tea intake against the development of prostate cancer, several phase 2 clinical trials have shown an inhibitory effect of green tea extract against the progression of prostate premalignant lesions to malignant tumors. Prospective epidemiologic studies so far have not provided evidence for a protective effect of green tea consumption on breast cancer development. Current data neither confirm nor refute a definitive cancer-preventive role of green tea intake. Large randomized intervention trials on the efficacy of green tea polyphenols or extracts are required before a recommendation for green tea consumption for cancer prevention should be made.
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Affiliation(s)
- Jian-Min Yuan
- University of Pittsburgh Cancer Institute and Department of Epidemiology, Graduate School of Public Health, University of Pittsburgh, Pittsburgh, PA
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Lambert JD. Does tea prevent cancer? Evidence from laboratory and human intervention studies. Am J Clin Nutr 2013; 98:1667S-1675S. [PMID: 24172300 DOI: 10.3945/ajcn.113.059352] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Tea (Camellia sinensis) is a widely consumed beverage and has been extensively studied for its cancer-preventive activity. Both the polyphenolic constituents as well as the caffeine in tea have been implicated as potential cancer-preventive compounds; the relative importance seems to depend on the cancer type. Green tea and the green tea catechin have been shown to inhibit tumorigenesis at a number of organ sites and to be effective when administered either during the initiation or postinitiation phases of carcinogenesis. Black tea, although not as well studied as green tea, has also shown cancer-preventive effects in laboratory models. A number of potential mechanisms have been proposed to account for the cancer-preventive effects of tea, including modulation of phase II metabolism, alterations in redox environment, inhibition of growth factor signaling, and others. In addition to the laboratory studies, there is a growing body of human intervention studies suggesting that tea can slow cancer progression and modify biomarkers relevant to carcinogenesis. Although available data are promising, many questions remain with regard to the dose-response relations of tea constituents in various models, the primary mechanisms of action, and the potential for combination chemoprevention strategies that involve tea as well as other dietary or pharmaceutical agents. The present review examines the available data from laboratory animal and human intervention studies on tea and cancer prevention. These data were evaluated, and areas for further research are identified.
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Affiliation(s)
- Joshua D Lambert
- Center of Excellence for Plant and Mushroom Foods for Health, the Department of Food Science, Pennsylvania State University, University Park, PA
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Qian G, Tang L, Wang F, Guo X, Massey ME, Williams JH, Phillips TD, Wang JS. Physiologically based toxicokinetics of serum aflatoxin B1-lysine adduct in F344 rats. Toxicology 2012; 303:147-51. [PMID: 23146766 DOI: 10.1016/j.tox.2012.10.020] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2012] [Revised: 10/09/2012] [Accepted: 10/15/2012] [Indexed: 10/27/2022]
Abstract
Aflatoxin B(1)-lysine adduct (AFB-Lys) is a reliable biomarker for aflatoxin exposure; however, a systematic toxicokinetic evaluation has not been reported. In this study, male F344 rats were orally exposed to single, or repeated, doses of AFB(1) and the toxicokinetics of serum AFB-Lys that followed treatments were investigated. A single-dose of AFB(1) increased serum AFB-Lys levels rapidly peaking at 4h, followed by first-order elimination, through which the half-life was estimated to be 2.31 days. A physiologically based pharmacokinetic model showed that approximately 3.00-3.90% and 1.12-1.98% of the administered AFB(1) doses were converted to serum AFB-Lys adducts at 2h and 24h post treatment, respectively. Repeated AFB(1) exposure at 5-25 μg/kg body weight linearly increased serum AFB-Lys levels for 5 weeks in animals, resulting in a 1-1.5 times higher AFB-Lys level overall. This indicates the potential of this adduct as a reliable biomarker for repeated low dose exposure. Higher dose exposure at 75 μg/kg increased the level of AFB-Lys to a maximum at 2 weeks, followed by a gradual decrease to near plateau level up to 5 weeks. In conclusion, this study systematically evaluated the toxicokinetics of serum AFB-Lys adduct in F344 rats using a physiologically based pharmacokinetic model and robust statistical modeling analysis and provided a firm and clear understanding of the toxicokinetics of this biomarker.
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Affiliation(s)
- Guoqing Qian
- Department of Environmental Health Science, the University of Georgia, Athens, GA 30602, USA
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40
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Khalaf A, Moselhy WA, Abdel-Hamed MI. The protective effect of green tea extract on lead induced oxidative and DNA damage on rat brain. Neurotoxicology 2012; 33:280-9. [DOI: 10.1016/j.neuro.2012.02.003] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2011] [Revised: 01/19/2012] [Accepted: 02/02/2012] [Indexed: 01/19/2023]
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Akiyama S, Nesumi A, Maeda-Yamamoto M, Uehara M, Murakami A. Effects of anthocyanin-rich tea "Sunrouge" on dextran sodium sulfate-induced colitis in mice. Biofactors 2012; 38:226-33. [PMID: 22422705 DOI: 10.1002/biof.1008] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/03/2011] [Accepted: 01/27/2012] [Indexed: 12/23/2022]
Abstract
Sunrouge, an anthocyanin-rich tea, has similar levels of catechins as "Yabukita," the most popular green tea cultivar consumed in Japan. Green tea polyphenols (GTPs) have attracted interest due to their potent antioxidative activities combined with a lack of side effects in humans at normal consumption levels. However, we previously reported that high doses (0.5 and 1%) of dietary GTPs can result in deterioration of colitis and failed to prevent colon carcinogenesis in inflamed colons. In the present study, we determined the inhibitory effects of Sunrouge on colitis in dextran sodium sulfate (DSS)-treated and untreated control mice. Five-week-old female ICR mice were administered a single dose of Yabukita or Sunrouge (extracts in 1 mL distilled water) via a stomach tube for 3 weeks. After 1 week of treatment, the mice were divided into four groups (two Yabukita and two Sunrouge groups) and given drinking water with or without 3% DSS for 2 weeks, then they were euthanized. Those treated with DSS developed watery diarrhea and bloody stools, and showed body weight loss, spleen hypertrophy, and shortening of the colon, as well as deteriorations in survival rate, liver function, colon mucosal interleukin-1β level and expression of phase II detoxification enzyme mRNA. Sunrouge improved these DSS-induced symptoms, at least in part, whereas Yabukita showed either no effect or adverse effects in regard to some those parameters. It is suggested that the differences between Yabukita and Sunrouge on DSS-induced colitis might be due to the high levels of anthocyanins found in Sunrouge tea.
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Affiliation(s)
- Satoko Akiyama
- Division of Food Science and Biotechnology, Graduate School of Agriculture, Kyoto University, Japan
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42
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Shimizu M, Adachi S, Masuda M, Kozawa O, Moriwaki H. Cancer chemoprevention with green tea catechins by targeting receptor tyrosine kinases. Mol Nutr Food Res 2011; 55:832-43. [PMID: 21538846 DOI: 10.1002/mnfr.201000622] [Citation(s) in RCA: 85] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2010] [Revised: 03/17/2011] [Accepted: 03/24/2011] [Indexed: 12/14/2022]
Abstract
Recent studies indicate that receptor tyrosine kinases (RTKs), which play important roles in cell proliferation, are one of the possible targets of green tea catechins (GTCs) in cancer cell growth inhibition. (-)-Epigallocatechin-3-gallate (EGCG), the major catechin in green tea, inhibits cell proliferation and induces apoptosis in various types of cancer cells, including colorectal cancer and hepatocellular carcinoma cells, by blocking the activation of the epidermal growth factor receptor (EGFR) family of RTKs. EGCG inhibits the activation of insulin-like growth factor-1 receptor (IGF-1R) and VEGFR2, the other members of the RTK family, and this effect is also associated with the anticancer and chemopreventive properties of this agent. EGCG suppresses the activation of EGFR in part by altering membrane lipid organization and causing the subsequent inhibition of the dimerization and activation of this receptor. Preliminary trials have shown that GTCs successfully prevent the development and progression of precancerous lesions, such as colorectal adenomas, without causing severe adverse effects. The present report reviews evidence indicating that GTCs exert anticancer and chemopreventive effects by inhibiting the activation of specific RTKs, especially EGFR, IGF-1R, and VEGFR2, and concludes that targeting RTKs and their related signaling pathways by using tea catechins could be a promising strategy for the prevention of human cancers.
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Affiliation(s)
- Masahito Shimizu
- Department of Gastroenterology, Gifu University Graduate School of Medicine, Gifu, Japan.
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43
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Forester SC, Lambert JD. The role of antioxidant versus pro-oxidant effects of green tea polyphenols in cancer prevention. Mol Nutr Food Res 2011; 55:844-54. [PMID: 21538850 DOI: 10.1002/mnfr.201000641] [Citation(s) in RCA: 222] [Impact Index Per Article: 17.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2010] [Revised: 02/25/2011] [Accepted: 03/17/2011] [Indexed: 12/21/2022]
Abstract
Consumption of green tea (Camellia sinensis) may provide protection against chronic diseases, including cancer. Green tea polyphenols are believed to be responsible for this cancer preventive effect, and the antioxidant activity of the green tea polyphenols has been implicated as a potential mechanism. This hypothesis has been difficult to study in vivo due to metabolism of these compounds and poor understanding of the redox environment in vivo. Green tea polyphenols can be direct antioxidants by scavenging reactive oxygen species or chelating transition metals as has been demonstrated in vitro. Alternatively, they may act indirectly by upregulating phase II antioxidant enzymes. Evidence of this latter effect has been observed in vivo, yet more work is required to determine under which conditions these mechanisms occur. Green tea polyphenols can also be potent pro-oxidants, both in vitro and in vivo, leading to the formation of hydrogen peroxide, the hydroxyl radical, and superoxide anion. The potential role of these pro-oxidant effects in the cancer preventive activity of green tea is not well understood. The evidence for not only the antioxidant, but also pro-oxidant, properties of green tea is discussed in the present review.
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Affiliation(s)
- Sarah C Forester
- Department of Food Science, The Pennsylvania State University, University Park, PA, USA
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44
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Yuan JM. Green tea and prevention of esophageal and lung cancers. Mol Nutr Food Res 2011; 55:886-904. [PMID: 21538848 DOI: 10.1002/mnfr.201000637] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2010] [Revised: 03/14/2011] [Accepted: 03/30/2011] [Indexed: 02/06/2023]
Abstract
Green tea contains high concentrations of tea polyphenols that have shown inhibitory effects against the development, progress, and growth of carcinogen-induced tumors in animal models at different organ sites, including the esophagus and lung. Green tea polyphenols also have shown to suppress cell proliferation and induce apoptosis. Besides antioxidative property, green tea polyphenols have pro-oxidative activities under certain conditions and modulate phase II metabolic enzymes that can enhance the detoxification pathway of environmental toxicants and carcinogens. Although epidemiological studies have provided inconclusive results on the effect of green tea consumption against the development of esophageal and lung cancers in humans overall, the inverse association between green tea intake and risk of esophageal cancer risk is more consistently observed in studies with adequate control for potential confounders. Epidemiological studies also have demonstrated an inverse, albeit moderate, association between green tea consumption and lung cancer, especially in non-smokers. This article reviews data on the cancer-preventive activities of green tea extract and green tea polyphenols and possible mechanisms against the esophageal and lung carcinogenesis in experimental animals, and summarizes the current knowledge from epidemiological studies on the relationship between green tea consumption and esophageal and lung cancer risk in humans.
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Affiliation(s)
- Jian-Min Yuan
- University of Minnesota Masonic Cancer Center, Minneapolis, MN, USA.
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Yang CS, Wang H. Mechanistic issues concerning cancer prevention by tea catechins. Mol Nutr Food Res 2011; 55:819-31. [PMID: 21538856 DOI: 10.1002/mnfr.201100036] [Citation(s) in RCA: 85] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2011] [Revised: 03/04/2011] [Accepted: 03/24/2011] [Indexed: 12/12/2022]
Abstract
The cancer preventive activities of tea (Camellia sinensis, Theaceae) have been demonstrated in animal models for cancers at different organ sites and suggested by some epidemiological studies. Many mechanisms for cancer prevention have been proposed based on studies in cell lines, which demonstrated the modulation of signal transduction and metabolic pathways by (-)-epigallocatechin-3-gallate (EGCG), the most abundant and active polyphenol in green tea. These molecular events may result in cellular changes, such as enhancement of apoptosis, suppression of cell proliferation, and inhibition of angiogenesis. Nevertheless, it is not known whether these are the molecular mechanisms of inhibition of carcinogenesis in animals and humans. This article discusses the key issues involved in extrapolating results from cell line studies to mechanistic information in vivo and in translating animal studies to human cancer prevention.
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Affiliation(s)
- Chung S Yang
- Department of Chemical Biology and Center for Cancer Prevention Research, Ernest Mario School of Pharmacy, Rutgers, The State University of New Jersey, Piscataway, NJ 08854-8020, USA.
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Yuan JM, Sun C, Butler LM. Tea and cancer prevention: epidemiological studies. Pharmacol Res 2011; 64:123-35. [PMID: 21419224 DOI: 10.1016/j.phrs.2011.03.002] [Citation(s) in RCA: 121] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/29/2010] [Accepted: 03/02/2011] [Indexed: 12/23/2022]
Abstract
Experimental studies have consistently shown the inhibitory activities of tea extracts on tumorigenesis in multiple model systems. Epidemiological studies, however, have produced inconclusive results in humans. A comprehensive review was conducted to assess the current knowledge on tea consumption and risk of cancers in humans. In general, consumption of black tea was not associated with lower risk of cancer. High intake of green tea was consistently associated with reduced risk of upper gastrointestinal tract cancers after sufficient control for confounders. Limited data support a protective effect of green tea on lung and hepatocellular carcinogenesis. Although observational studies do not support a beneficial role of tea intake on prostate cancer risk, phase II clinical trials have demonstrated an inhibitory effect of green tea extract against the progression of prostate pre-malignant lesions. Green tea may exert beneficial effects against mammary carcinogenesis in premenopausal women and recurrence of breast cancer. There is no sufficient evidence that supports a protective role of tea intake on the development of cancers of the colorectum, pancreas, urinary tract, glioma, lymphoma, and leukemia. Future prospective observational studies with biomarkers of exposure and phase III clinical trials are required to provide definitive evidence for the hypothesized beneficial effect of tea consumption on cancer formation in humans.
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Affiliation(s)
- Jian-Min Yuan
- The Masonic Cancer Center, and Division of Epidemiology and Community Health, School of Public Health, University of Minnesota, 425 East River Road, 554 MCRB, Minneapolis, MN 55455, USA.
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Cancer prevention by tea: Evidence from laboratory studies. Pharmacol Res 2011; 64:113-22. [PMID: 21397027 DOI: 10.1016/j.phrs.2011.03.001] [Citation(s) in RCA: 158] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/22/2010] [Revised: 03/02/2011] [Accepted: 03/02/2011] [Indexed: 12/30/2022]
Abstract
The cancer preventive activities of tea (Camellia sinensis Theaceae) have been studied extensively. Inhibition of tumorigenesis by green tea extracts and tea polyphenols has been demonstrated in different animal models, including those for cancers of the skin, lung, oral cavity, esophagus, stomach, small intestine, colon, bladder, liver, pancreas, prostate, and mammary glands. Many studies in cell lines have demonstrated the modulation of signal transduction and metabolic pathways by (-)-epigallocatechin-3-gallate (EGCG), the most abundant and active polyphenol in green tea. These molecular events can result in cellular changes, such as enhancement of apoptosis, suppression of cell proliferation, and inhibition of angiogenesis. Nevertheless, the molecular mechanisms of inhibition of carcinogenesis in animals and humans remain to be further investigated. Future research directions in this area are discussed.
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Kensler TW, Roebuck BD, Wogan GN, Groopman JD. Aflatoxin: a 50-year odyssey of mechanistic and translational toxicology. Toxicol Sci 2011; 120 Suppl 1:S28-48. [PMID: 20881231 PMCID: PMC3043084 DOI: 10.1093/toxsci/kfq283] [Citation(s) in RCA: 397] [Impact Index Per Article: 30.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2010] [Accepted: 09/07/2010] [Indexed: 12/16/2022] Open
Abstract
Since their discovery 50 years ago, the aflatoxins have become recognized as ubiquitous contaminants of the human food supply throughout the economically developing world. The adverse toxicological consequences of these compounds in populations are quite varied because of a wide range of exposures leading to acute effects, including rapid death, and chronic outcomes such as hepatocellular carcinoma. Furthermore, emerging studies describe a variety of general adverse health effects associated with aflatoxin, such as impaired growth in children. Aflatoxin exposures have also been demonstrated to multiplicatively increase the risk of liver cancer in people chronically infected with hepatitis B virus (HBV) illustrating the deleterious impact that even low toxin levels in the diet can pose for human health. The public health impact of aflatoxin exposure is pervasive. Aflatoxin biomarkers of internal and biologically effective doses have been integral to the establishment of the etiologic role of this toxin in human disease through better estimates of exposure, expanded knowledge of the mechanisms of disease pathogenesis, and as tools for implementing and evaluating preventive interventions.
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Affiliation(s)
- Thomas W Kensler
- Department of Environmental Health Sciences, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland 21205, USA.
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Abstract
Extracts of green tea and green tea polyphenols have exhibited inhibitory effects against the formation and development of tumors at different organ sites in animals. These include animal models for skin, lung, oral cavity, esophagus, stomach, intestine, colon, liver, pancreas, bladder, mammary gland, and prostate cancers. In addition to suppressing cell proliferation, promoting apoptosis, and modulating signaling transduction, green tea polyphenols, especially (-)-epigallocatechin-3-gallate, also inhibit cell invasion, angiogenesis, and metastasis. This article reviews data on the cancer preventive activities of green tea polyphenols, possible mechanisms involved, and the relationship between green tea consumption and human cancer risk.
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Affiliation(s)
- Chung S Yang
- Department of Chemical Biology, Rutgers, the State University of New Jersey, Piscataway, New Jersey 08854-8020, USA.
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Wu F, Khlangwiset P. Evaluating the technical feasibility of aflatoxin risk reduction strategies in Africa. Food Addit Contam Part A Chem Anal Control Expo Risk Assess 2010; 27:658-76. [PMID: 20455160 DOI: 10.1080/19440041003639582] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
Public health interventions must be readily accepted by their target populations to have any meaningful impact and must have financial and infrastructural support to be feasible in the parts of the world where they are most needed. At the same time, these interventions must be assessed for potential unintended consequences, either to the environment or to human health. In this paper, we evaluate the technical feasibility of interventions to control aflatoxin risk, to be potentially deployed in parts of Africa where aflatoxin exposure poses a significant public health concern. We have applied a conceptual framework for feasibility to four interventions, one associated with each of four different stages of aflatoxin risk: biocontrol (pre-harvest), a post-harvest intervention package (post-harvest), NovaSil clay (dietary), and hepatitis B vaccination (clinical). For each intervention, we have assessed the following four components of technical feasibility: (1) characteristics of the basic intervention, (2) characteristics of delivery, (3) requirements on government capacity, and (4) usage characteristics. We propose ways in which feasibility of each intervention is currently high or low from the perspective of adoption in Africa, how public education is crucial for each of these interventions to succeed, and how to align economic incentives to make the interventions more suitable for less developed countries.
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Affiliation(s)
- Felicia Wu
- Department of Environmental and Occupational Health, University of Pittsburgh, Pittsburgh, PA 15219, USA.
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