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Abstract
Conjugated linoleic acids (CLA) are distinctive polyunsaturated fatty acids. They are present in food produced by ruminant animals and they are accumulated in seeds of certain plants. These naturally occurring substances have demonstrated to have anti-carcinogenic activity. Their potential effect to inhibit cancer has been shown in vivo and in vitro studies. In this review, we present the multiple effects of CLA isomers on cancer development such as anti-tumor efficiency, anti-mutagenic and anti-oxidant activity. Although the majority of the studies in vivo and in vitro summarized in this review have demonstrated beneficial effects of CLA on the proliferation and apoptosis of tumor cells, further experimental work is needed to estimate the true value of CLA as a real anti-cancer agent.
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Haskins CP, Henderson G, Champ CE. Meat, eggs, full-fat dairy, and nutritional boogeymen: Does the way in which animals are raised affect health differently in humans? Crit Rev Food Sci Nutr 2018; 59:2709-2719. [PMID: 29672133 DOI: 10.1080/10408398.2018.1465888] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/09/2023]
Abstract
Background: Food recommendations to improve cancer prevention are generally based on epidemiologic data and remain inconsistent. These epidemiologic studies, while controversial, have generally produced results that caution against the consumption of high-fat foods, including eggs, red meat, and full-fat dairy, such as butter and cheese. Yet, limited data exist assessing the quality of individual sources of these foods and the effect each has after its consumption. This study set out to assess the impact sources of food within the same groups from animals raised differently on variables associated with health in human studies. Methods and Materials: A search was conducted through MEDLINE, Embase, and PubMed. In total, twenty-nine studies met inclusion criteria, measuring physiologic changes in humans after consuming animal products following animal diet manipulation. A meta-analysis was attempted to assess the differences between the cohorts in these studies, but was aborted due to poor study quality, vast differences in study design, and a limited number of studies. Results: Studies varied by animal, animal diet manipulation, food product, and overall design. Significant differences were present between groups eating the same food (cheese, beef, eggs, and butter) from animals raised differently, including levels of: conjugated linoleic acid, omega-3 fatty acids (alpha linoleic acid [ALA], docosahexaenoic acid [DHA], and eicosapentaenoic acid [EPA]), and inflammatory factors (triacyl glycerol [TAG], interleukin-6 [IL-6], interleukin-8 [IL-8], tumor necrosis factor [TNF], and C-reactive protein [CRP]). Lipid levels were minimally affected. Conclusions: This work highlights differences in human health markers after consumption of the same foods from animals raised differently. Overall, lipid levels remained relatively neutral, but significant changes in inflammatory and other serum markers and phospholipids were present. Future studies and dietary recommendations should consider how animals are raised, as this can produce different effects on health markers.
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Affiliation(s)
| | - George Henderson
- Human Potential Centre, Auckland University of Technology , Auckland , New Zealand
| | - Colin E Champ
- Department of Radiation Oncology, University of Pittsburgh Medical Center , Pittsburgh , PA , United States
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Subchronic perfluorooctanesulfonate (PFOS) exposure induces elevated mutant frequency in an in vivo λ transgenic medaka mutation assay. Sci Rep 2016; 6:38466. [PMID: 27929129 PMCID: PMC5144067 DOI: 10.1038/srep38466] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2016] [Accepted: 11/09/2016] [Indexed: 01/09/2023] Open
Abstract
Perfluorooctanesulfonate (PFOS) has been widely detected in the environment, wildlife and humans, but few studies have ever examined its mutagenic effect in vivo. In the present study, we use a transgenic fish model, the λ transgenic medaka, to evaluate the potential mutagenicity of PFOS in vivo following a subchronic exposure of 30 days. The mutant frequency of cII target gene was 3.46 × 10-5 in liver tissue from control fish, which increased by 1.4-fold to 4.86 × 10-5 in fish exposed to 6.7 μg/L PFOS, 1.55-fold to 5.36 × 10-5 in fish exposed to 27.6 μg/L PFOS, and 2.02-fold to 6.99 × 10-5 in fish exposed to 87.6 μg/L PFOS. This dose-dependent increase of mutant frequency was also accompanied with mutational spectrum changes associated with PFOS exposure. In particular, PFOS-induced mutation was characterized by +1 frameshift mutations, which increased from 0% in control fish to 13.2% in fish exposed to 27.6 μg/L PFOS and 14.6% in fish exposed to 87.6 μg/L PFOS. Our findings provide the first evidence of PFOS's mutagenicity in an aquatic model system. Given the fact that most conventional mutagenic assays were negative for PFOS, we propose that PFOS-induced mutation in liver tissue of λ transgenic medaka may be mediated through compromised liver function.
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Heinze VM, Actis AB. Dietary conjugated linoleic acid and long-chain n-3 fatty acids in mammary and prostate cancer protection: a review. Int J Food Sci Nutr 2011; 63:66-78. [PMID: 21762028 DOI: 10.3109/09637486.2011.598849] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
The role of dietary fatty acids on cancer is still controversial. To examine the current literature on the protective role of conjugated linoleic acid (CLA) and marine long-chain fatty acids [eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA)] and the risk of breast and prostate cancer, data from 41 case-control and cohort studies and relevant in vitro and animal experiments were included in this 2000-2010 revision. Epidemiological studies on CLA intake or its tissue concentration related to breast and prostate tumorigenesis are not conclusive; EPA and DHA intake have shown important inverse associations just in some studies. Additional research on the analysed association is required.
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Affiliation(s)
- Verónica M Heinze
- Facultad de Ciencias de la Salud, Universidad Adventista del Plata, 25 de Mayo 99, 3103 Libertador San Martín, Entre Ríos, Argentina.
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Al Ashaal HA, Farghaly AA, Abd El Aziz MM, Ali MA. Phytochemical investigation and medicinal evaluation of fixed oil of Balanites aegyptiaca fruits (Balantiaceae). JOURNAL OF ETHNOPHARMACOLOGY 2010; 127:495-501. [PMID: 19833185 DOI: 10.1016/j.jep.2009.10.007] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/28/2009] [Revised: 10/04/2009] [Accepted: 10/06/2009] [Indexed: 05/28/2023]
Abstract
ETHNOPHARMACOLOGICAL RELEVANCE Balanites aegyptiaca (Balantiaceae), mainly the fruit, is used by traditional healers and herbalists for treating many diseases in Africa and Asia. AIM OF THE STUDY Investigation of fixed oil composition of fruits and evaluation of its biological activity. MATERIALS AND METHODS Oil content was identified using GC and GC/MS. In vitro examination of the oil biological activity (including cytotoxicity, antimutagenicity, antiparasitic, antiviral and antimicrobial activities) was performed. RESULTS The oil contained 54.53% unsaturated fatty acids and 1.14% sterols. The oil exhibited anticancer activity against lung, liver and brain human carcinoma cell lines. It also had antimutagenic activity against Fasciola gigantica induced mutagenicity besides anthelmintic activity against hepatic worms (Schistosoma mansoni and Fasciola gigantica). Preliminary screening showed that the oil had antiviral activity against Herpes simplex virus. It also had antimicrobial activity against selected strains of Gram-positive bacteria, Gram-negative bacteria and Candida. CONCLUSION The results showed remarkable biological activity of Balanites aegyptiaca fixed oil and proved its importance as natural bioactive source.
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Affiliation(s)
- Hanan A Al Ashaal
- Research of Drugs and Pharmaceutical Industries Division, National Research Center, Dokki, Egypt.
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Winn RN, Norris MB, Lothenbach D, Flynn K, Hammermeister D, Whiteman F, Sheedy B, Johnson R. Sub-chronic exposure to 1,1-dichloropropene induces frameshift mutations in lambda transgenic medaka. Mutat Res 2006; 595:52-9. [PMID: 16337249 DOI: 10.1016/j.mrfmmm.2005.10.009] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2005] [Revised: 10/13/2005] [Accepted: 10/14/2005] [Indexed: 05/05/2023]
Abstract
1,1-Dichloropropene (1,1-DCP) is a contaminant present in both ground and surface waters used as sources for drinking water. Structural similarity to several compounds with known mutagenicity and carcinogenicity, and recent demonstration of mutagenicity in vitro, suggest this compound may be similarly mutagenic in vivo. A transgenic fish model, the lamda transgenic medaka, was used to evaluate the potential mutagenicity of this contaminant in vivo following sub-chronic exposure for 6 weeks. Mutant frequencies of the cII target gene (MF) increased six-fold in the livers of fish exposed to the lowest 1,1-DCP exposure concentration (0.44 mg/L, MF = 18.4 x 10(-5), and increased with each treatment, culminating in a 32-fold induction in fish from the highest 1,1-DCP treatment (16.60 mg/L, MF = 96.3 x 10(-5). Mutations recovered from treated fish showed a distinctive mutational spectrum comprised predominantly of +1 frameshift mutations, induced 166-fold above that of untreated animals. The majority of frameshifts were +1 insertions at thiamine and adenine. These results represent the first evidence of mutagenicity of 1,1-DCP in vivo, and of the highly characteristic spectrum of induced mutations dominated by +1 frameshift mutations. Based upon results from previous in vitro studies, the similar role of glutathione S-transferase (GSTT1-1) in the activation of 1,1-DCP to a mutagen in vivo is also suggested. This study further illustrates the utility of the lamda transgenic medaka as a model for identifying and characterizing potential genetic health risks associated with chemical exposures in the environment.
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Affiliation(s)
- Richard N Winn
- Aquatic Biotechnology and Environmental Laboratory, Warnell School of Forest Resources, University of Georgia, Athens, GA, USA.
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Lambert IB, Singer TM, Boucher SE, Douglas GR. Detailed review of transgenic rodent mutation assays. Mutat Res 2005; 590:1-280. [PMID: 16081315 DOI: 10.1016/j.mrrev.2005.04.002] [Citation(s) in RCA: 252] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2005] [Revised: 04/04/2005] [Accepted: 04/12/2005] [Indexed: 11/17/2022]
Abstract
Induced chromosomal and gene mutations play a role in carcinogenesis and may be involved in the production of birth defects and other disease conditions. While it is widely accepted that in vivo mutation assays are more relevant to the human condition than are in vitro assays, our ability to evaluate mutagenesis in vivo in a broad range of tissues has historically been quite limited. The development of transgenic rodent (TGR) mutation models has given us the ability to detect, quantify, and sequence mutations in a range of somatic and germ cells. This document provides a comprehensive review of the TGR mutation assay literature and assesses the potential use of these assays in a regulatory context. The information is arranged as follows. (1) TGR mutagenicity models and their use for the analysis of gene and chromosomal mutation are fully described. (2) The principles underlying current OECD tests for the assessment of genotoxicity in vitro and in vivo, and also nontransgenic assays available for assessment of gene mutation, are described. (3) All available information pertaining to the conduct of TGR assays and important parameters of assay performance have been tabulated and analyzed. (4) The performance of TGR assays, both in isolation and as part of a battery of in vitro and in vivo short-term genotoxicity tests, in predicting carcinogenicity is described. (5) Recommendations are made regarding the experimental parameters for TGR assays, and the use of TGR assays in a regulatory context.
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Affiliation(s)
- Iain B Lambert
- Mutagenesis Section, Environmental Health Sciences Bureau, Healthy Environments and Consumer Safety Branch, 0803A, Health Canada, Ottawa, Ont., Canada K1A 0L2.
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Nozawa H, Nakao W, Takata J, Arimoto-Kobayashi S, Kondo K. Inhibition of PhIP-induced mammary carcinogenesis in female rats by ingestion of freeze-dried beer. Cancer Lett 2005; 235:121-9. [PMID: 15946793 DOI: 10.1016/j.canlet.2005.04.020] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2005] [Revised: 04/10/2005] [Accepted: 04/11/2005] [Indexed: 12/25/2022]
Abstract
This study evaluated the modulating effect of non-alcoholic constituents of beer on 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP)-induced mammary carcinogenesis. Female Sprague-Dawley (SD) rats at 6 weeks of age were divided into four groups (n=26-30) and fed either a high fat diet or high fat diets containing 1, 2 or 4% freeze-dried beer (FD beer). One week after the start of feeding, rats received PhIP at a dose of 85 mg/kg by gavage four times weekly for 2 weeks. There were no differences in the body weights or diet intakes of rats between the control and the experimental groups. Weekly observation of palpable tumors indicated that tumor incidence and tumor multiplicity in the 2 and 4% FD beer groups were lower than in the control group throughout the experiment. Neoplastic lesions were pathologically examined at the end of the 22-weeks experiment. Tumor development was inhibited by FD beer intake in a dose-dependent manner. Tumor incidence (38.5%) and tumor multiplicity (0.8+/-0.4) for the group fed with a diet containing 4% FD were significantly reduced as compared with the control group (73.3% and 1.8+/-0.7). Supplementation with FD beer for 3 weeks together with the PhIP treatments resulted in increased liver GST activity, decreased liver CYP1A2 activity and a decrease in the number of DNA adducts in the mammary tissue, though these values were not significant. In conclusion, our results suggest that intake of FD beer may reduce the risk of carcinogenesis caused by heterocyclic amines.
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Affiliation(s)
- Hajime Nozawa
- Central Laboratories for Key Technology, Kirin Brewery Co. Ltd, 1-13-5 Fukuura, Yokohama 236-0004, Japan.
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Wahle KWJ, Heys SD, Rotondo D. Conjugated linoleic acids: are they beneficial or detrimental to health? Prog Lipid Res 2004; 43:553-87. [PMID: 15522764 DOI: 10.1016/j.plipres.2004.08.002] [Citation(s) in RCA: 381] [Impact Index Per Article: 19.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2004] [Revised: 08/12/2004] [Accepted: 08/23/2004] [Indexed: 11/29/2022]
Abstract
Conjugated linoleic acids (CLAs) comprise a family of positional and geometric isomers of linoleic acid (18:2n-6; LA) that are formed by biohydrogenation and oxidation processes in nature. The major dietary sources of these unusual fatty acids are foods derived from ruminant animals, in particular dairy products. The main form of CLA, cis-9, trans-11-18:2, can be produced directly by bacterial hydrogenation in the rumen or by delta-9 desaturation of the co-product vaccenic acid (trans-11-18:1) in most mammalian tissues including man. The second most abundant isomer of CLA is the trans-10, cis-12-18:2 form. Initially identified in grilled beef as a potential anti-carcinogen a surprising number of health benefits have subsequently been attributed to CLA mixtures and more recently to the main individual isoforms. It is also clear from recent studies that the two main isoforms can have different effects on metabolism and cell functions and can act through different cell signalling pathways. The majority of studies on body compositional effects (i.e. fat loss, lean gain), on cancer and cardiovascular disease attenuation, on insulin sensitivity and diabetes and on immune function have been conducted with a variety of animal models. Observations clearly emphasise that differences exist between mammalian species in their response to CLAs with mice being the most sensitive. Recent studies indicate that some but not all of the effects observed in animals also pertain to human volunteers. Reports of detrimental effects of CLA intake appear to be largely in mice and due mainly to the trans-10, cis-12 isomer. Suggestions of possible deleterious effects in man due to an increase in oxidative lipid products (isoprostanes) with trans-10, cis-12 CLA ingestion require substantiation. Unresponsiveness to antioxidants of these non-enzymatic oxidation products casts some doubt on their physiological relevance. Recent reports, albeit in the minority, that CLAs, particularly the trans-10, cis-12 isomer, can elicit pro-carcinogenic effects in animal models of colon and prostate cancer and can increase prostaglandin production in cells also warrant further investigation and critical evaluation in relation to the many published anti-cancer and anti-prostaglandin effects of CLAs.
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Affiliation(s)
- Klaus W J Wahle
- School of Life Sciences, The Robert Gordon University, Aberdeen AB 25 1GH, UK.
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Field CJ, Schley PD. Evidence for potential mechanisms for the effect of conjugated linoleic acid on tumor metabolism and immune function: lessons from n-3 fatty acids. Am J Clin Nutr 2004; 79:1190S-1198S. [PMID: 15159256 DOI: 10.1093/ajcn/79.6.1190s] [Citation(s) in RCA: 72] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Conjugated linoleic acid (CLA) and the long-chain polyunsaturated n-3 fatty acids have been shown in vivo and in vitro to reduce tumor growth. Tumor growth could occur by slowing or stopping cell replication (by interfering with transition through the cell cycle), increasing cell death (via necrosis and/or apoptosis), or both. The anticancer effects of fatty acids, shown in vivo, could also be mediated by effects on the host's immune system. Although it is widely recognized that n-3 fatty acids can alter immune and inflammatory responses, considerably less is known about CLA. For n-3 fatty acids, several candidate mechanisms have been proposed for their immune effects, including changes in 1) membrane structure and composition, 2) membrane-mediated functions and signals (eg, proteins, eicosanoids), 3) gene expression, and 4) immune development. Considerable work has been done that shows the potential importance of CLA as an anticancer treatment; however, many questions remain as to how this effect occurs. This review summarizes the CLA and cancer literature and then uses the evidence for the anticancer immune and tumor properties of the long-chain n-3 fatty acids docosahexaenoic and eicosapentaenoic acids to suggest future research directions for mechanistic studies on CLA and cancer.
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Affiliation(s)
- Catherine J Field
- Department of Agricultural, Food and Nutritional Science, University of Alberta, Edmonton, Canada.
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