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Nkolisa N, Magwaza LS, Workneh TS, Chimphango A, Sithole NJ. Postharvest quality and bioactive properties of tomatoes ( Solanum lycopersicum) stored in a low-cost and energy-free evaporative cooling system. Heliyon 2019; 5:e02266. [PMID: 31440600 PMCID: PMC6699420 DOI: 10.1016/j.heliyon.2019.e02266] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2019] [Revised: 05/08/2019] [Accepted: 08/06/2019] [Indexed: 12/03/2022] Open
Abstract
The aim of this study was to investigate the effect of low cost evaporative cooling system on the quality of two tomato cultivars, namely, 9065 jam and round tomatoes. Both the tomato cultivars were harvested from a smallholder farmer's field at Umsinga and stored for 20 days in one of the three storage conditions namely; cold room (CR), room temperature (RT) and evaporative cooling system (ECS) and sampling done every 5 days. The tomato samples were laid out as a factorial design with four replications. Results obtained proved that the storage conditions and storage period had a significant effect (p < 0.05) on the lycopene content (LC), antioxidants, total phenolic content (TPC) and ascorbic acid (AA) of the tomato samples. A decreasing trend with storage time was observed for antioxidants and TPC for both the cultivars whilst there was an increasing trend of AA and lycopene content on both the cultivars stored in the different storage conditions. Ascorbic acid was highest in samples stored in RT (0.173 mg/100g for round tomatoes; 0.172 mg/100g for 9065 jam tomatoes), second highest in samples stored under ECS (0.16 mg/100g for round; 0.17 mg/100g for 9065 jam) and lowest in samples inside the CR (0.11 mg/100g; 0.12 mg/100g for 9065 jam). Lycopene content was highest in samples stored in RT (45.31 mg/100g for round tomatoes; 52.9 mg/100g for 9065 jam tomatoes) second highest in samples stored under ECS (32.46 mg/100g for round tomatoes; 42.98 mg/100g for 9065 jam tomatoes) and lowest in samples inside the CR (14.16 mg/100g for round tomatoes; 8.79 mg/100g for 9065 jam tomatoes). Total phenolic content was highest in samples stored in CR (0.17 mg/100g GAE for round tomatoes; 0.19 mg/100g GAE for 9065 jam tomatoes) second highest in samples stored under ECS (0.124 mg/100g GAE for round tomatoes; 0.126 mg/100g GAE for 9065 jam tomatoes) and lowest in samples inside the RT (0.11 mg/100g GAE for round tomatoes; 0.12 mg/100g GAE for 9065 jam tomatoes). Antioxidant activities were highest in samples stored in CR (2.05 mg/100g for round tomatoes; 2.03 mg/100g for 9065 jam tomatoes), followed by samples stored under ECS (1.82 mg/100g for round tomatoes; 1.96 mg/100g for 9065 jam tomatoes) and lowest in samples inside the RT (1.02 mg/100g for round tomatoes; 1.07 mg/100 g for 9065 jam tomatoes). The correlation relationship among cultivars was positive and PCA proved that the cultivars were similar. Although CR provided the best storage condition for the investigated parameters, the results provided sufficient evidence that ECS can be the best method to increase shelf life in rural communities due to its association with cost reduction.
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Affiliation(s)
- Ntombizandile Nkolisa
- Discipline of Crop and Horticultural Science, School of Agricultural, Earth and Environmental Sciences, University of KwaZulu-Natal, Private Bag X01, Scottsville, 3209, Pietermaritzburg, South Africa
| | - Lembe S. Magwaza
- Discipline of Crop and Horticultural Science, School of Agricultural, Earth and Environmental Sciences, University of KwaZulu-Natal, Private Bag X01, Scottsville, 3209, Pietermaritzburg, South Africa
- Corresponding author.
| | - Tilahun S. Workneh
- Bioresources Engineering, School of Engineering, University of KwaZulu-Natal, Private Bag X01, Scottsville, 3209, Pietermaritzburg, South Africa
| | - Annie Chimphango
- Processing Engineering Department, Stellenbosch University, Private Bag X1, Matieland 7602, Stellenbosch, South Africa
| | - Nkanyiso J. Sithole
- Discipline of Crop and Horticultural Science, School of Agricultural, Earth and Environmental Sciences, University of KwaZulu-Natal, Private Bag X01, Scottsville, 3209, Pietermaritzburg, South Africa
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Iijima K, Shimosegawa T. Involvement of luminal nitric oxide in the pathogenesis of the gastroesophageal reflux disease spectrum. J Gastroenterol Hepatol 2014; 29:898-905. [PMID: 24863184 DOI: 10.1111/jgh.12548] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 01/29/2014] [Indexed: 12/16/2022]
Abstract
Over the last 3 decades, the incidence of esophageal adenocarcinoma has dramatically increased in Western countries; a similar increase may be observed in Asian countries in the near future. Esophageal adenocarcinoma arises from a sequential gastroesophageal reflux disease (GERD) spectrum from reflux erosive esophagitis, to Barrett's esophagus, and finally to esophageal adenocarcinoma. At present, gastric acid and bile are assumed to be primarily involved in the etiology of the GERD spectrum. We reported in 2002 that, at the gastroesophageal junction in humans, abundant amounts of nitric oxide (NO) are generated luminally through the entero-salivary re-circulation of dietary nitrate. Since then, we have carried out a series of experiments to demonstrate that NO diffuses into the adjacent epithelium at cytotoxic levels. This diffusion results in disruption of the epithelial barrier function, exacerbation of inflammation, acceleration of columnar transformation in the esophagus (Barrett's esophagus) via the induction of caudal-type homeobox 2, and the shifting of carcinogenic N-nitroso compound formation from the luminal to epithelial compartment. These results suggest that, in addition to conventionally recognized causative factors, luminal NO could also be involved in the pathogenesis of the GERD spectrum. In addition, we recently showed that there is a prominent gender-related difference in NO-related cytotoxicity in the esophagus and that estrogen attenuated the esophageal tissue damage via the estrogen receptor in female rats. The role of estrogen in attenuating the esophageal tissue damage in NO-related esophageal damage could explain the well-recognized male predominance in the GERD spectrum in humans.
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Affiliation(s)
- Katsunori Iijima
- Division of Gastroenterology, Tohoku University Graduate School of Medicine, Sendai, Japan
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Lidder S, Webb AJ. Vascular effects of dietary nitrate (as found in green leafy vegetables and beetroot) via the nitrate-nitrite-nitric oxide pathway. Br J Clin Pharmacol 2013; 75:677-96. [PMID: 22882425 DOI: 10.1111/j.1365-2125.2012.04420.x] [Citation(s) in RCA: 209] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2012] [Accepted: 08/05/2012] [Indexed: 02/06/2023] Open
Abstract
The discovery that dietary (inorganic) nitrate has important vascular effects came from the relatively recent realization of the 'nitrate-nitrite-nitric oxide (NO) pathway'. Dietary nitrate has been demonstrated to have a range of beneficial vascular effects, including reducing blood pressure, inhibiting platelet aggregation, preserving or improving endothelial dysfunction, enhancing exercise performance in healthy individuals and patients with peripheral arterial disease. Pre-clinical studies with nitrate or nitrite also show the potential to protect against ischaemia-reperfusion injury and reduce arterial stiffness, inflammation and intimal thickness. However, there is a need for good evidence for hard endpoints beyond epidemiological studies. Whilst these suggest reduction in cardiovascular risk with diets high in nitrate-rich vegetables (such as a Mediterranean diet), others have suggested possible small positive and negative associations with dietary nitrate and cancer, but these remain unproven. Interactions with other nutrients, such as vitamin C, polyphenols and fatty acids may enhance or inhibit these effects. In order to provide simple guidance on nitrate intake from different vegetables, we have developed the Nitrate 'Veg-Table' with 'Nitrate Units' [each unit being 1 mmol of nitrate (62 mg)] to achieve a nitrate intake that is likely to be sufficient to derive benefit, but also to minimize the risk of potential side effects from excessive ingestion, given the current available evidence. The lack of data concerning the long term effects of dietary nitrate is a limitation, and this will need to be addressed in future trials.
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Affiliation(s)
- Satnam Lidder
- King's College London British Heart Foundation Centre, Cardiovascular Division, Department of Clinical Pharmacology, St.Thomas' Hospital, London, UK
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Andersen FA. Annual Review of Cosmetic Ingredient Safety Assessments: 2007-2010. Int J Toxicol 2011; 30:73S-127S. [DOI: 10.1177/1091581811412618] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
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Ishiyama F, Iijima K, Asanuma K, Ara N, Yoshitake J, Abe Y, Koike T, Imatani A, Ohara S, Shimosegawa T. Exogenous luminal nitric oxide exacerbates esophagus tissue damage in a reflux esophagitis model of rats. Scand J Gastroenterol 2009; 44:527-37. [PMID: 19172433 DOI: 10.1080/00365520802699260] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
OBJECTIVE Cytotoxic concentrations of nitric oxide are generated luminally at the gastroesophageal junction through the entero-salivary recirculation of dietary nitrate in humans. The site of luminal nitric oxide generation shifts to the lower esophagus when gastric acid is refluxed into the esophagus. The aim of this study was to investigate the influence of persistent administration of exogenous nitric oxide on esophageal damage. MATERIAL AND METHODS 0.1% sodium nitrite and/or 1% ascorbic acid was administered in an established rat acid-refluxed esophagitis model. Co-administration of both reactants in this model is thought to induce high concentrations of nitric oxide luminally in the esophagus by an acid-catalyzed chemical reaction when refluxed gastric acid is present. The tissue damage was evaluated by a macroscopic lesion index and myeloperoxidase activity. Nitrotyrosin was assessed immunohistochemically as a footprint of peroxynitrite formation. RESULTS Co-administration of sodium nitrite and ascorbic acid induced a 4- to 5-fold increase in the esophageal damage compared with baseline reflux esophagitis, while the damage was unchanged when either of the reagents alone was given. Nitrotyrosine was strongly stained in the tissue from the co-administration. Treatment of superoxide scavengers efficiently prevented the exacerbation of esophageal damage by exogenous nitric oxide exposure, suggesting an essential role of superoxide in esophageal damage. CONCLUSIONS Exogenous luminal nitric oxide greatly exacerbated the tissue damage of reflux esophagitis. Diffusion of the luminal nitric oxide into the adjacent superoxide-enriched inflamed tissue of the esophagus could lead to the production of the highly toxic agent peroxynitrite, thus causing exacerbation of the esophageal damage.
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Affiliation(s)
- Fumitake Ishiyama
- Division of Gastroenterology, Tohoku University Graduate School of Medicine, Sendai, Miyagi, Japan
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Hassan HA, El-Agmy SM, Gaur RL, Fernando A, Raj MHG, Ouhtit A. In vivo evidence of hepato- and reno-protective effect of garlic oil against sodium nitrite-induced oxidative stress. Int J Biol Sci 2009; 5:249-55. [PMID: 19305642 PMCID: PMC2659008 DOI: 10.7150/ijbs.5.249] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2008] [Accepted: 02/26/2009] [Indexed: 01/11/2023] Open
Abstract
Sodium nitrite (NaNO2), a food color fixative and preservative, contributes to carcinogenesis. We investigated the protective role of garlic oil against NaNO2-induced abnormalities in metabolic biochemical parameters and oxidative status in male albino rats. NaNO2 treatment for a period of three months induced a significant increase in serum levels of glucose, aspartate aminotransferase (AST), alanine aminotransferase (ALT), alkaline phosphatase (ALP), bilirubin, urea and creatinine as well as hepatic AST and ALT. However, significant decrease was recorded in liver ALP activity, glycogen content, and renal urea and creatinine levels. In parallel, a significant increase in lipid peroxidation, and a decrease in glutathione content and catalase activity were observed in the liver and the kidney. However, garlic oil supplementation showed a remarkable amelioration of these abnormalities. Our data indicate that garlic is a phytoantioxidant with powerful chemopreventive properties against chemically-induced oxidative stress.
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Affiliation(s)
- Hanaa A Hassan
- 1. Department of Zoology, Faculty of Science, Mansoura University, Mansoura, Egypt
| | - Sherif M El-Agmy
- 1. Department of Zoology, Faculty of Science, Mansoura University, Mansoura, Egypt
| | - Rajiv L Gaur
- 2. Department of Pathology and Department of Genetics, Stanley S. Scott Cancer Center, Louisiana State University Health Science Center, New Orleans, Louisiana, USA
| | - Augusta Fernando
- 2. Department of Pathology and Department of Genetics, Stanley S. Scott Cancer Center, Louisiana State University Health Science Center, New Orleans, Louisiana, USA
| | - Madhwa HG Raj
- 3. Department of Ob Gyn and Biochemistry, Stanley S. Scott Cancer Center, Louisiana State University Health Science Center, New Orleans, Louisiana, USA
| | - Allal Ouhtit
- 2. Department of Pathology and Department of Genetics, Stanley S. Scott Cancer Center, Louisiana State University Health Science Center, New Orleans, Louisiana, USA
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Kuroiwa Y, Okamura T, Ishii Y, Umemura T, Tasaki M, Kanki K, Mitsumori K, Hirose M, Nishikawa A. Enhancement of esophageal carcinogenesis in acid reflux model rats treated with ascorbic acid and sodium nitrite in combination with or without initiation. Cancer Sci 2008; 99:7-13. [PMID: 17953708 PMCID: PMC11158633 DOI: 10.1111/j.1349-7006.2007.00649.x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2007] [Revised: 09/12/2007] [Accepted: 09/19/2007] [Indexed: 11/29/2022] Open
Abstract
Combined treatment with sodium nitrite (NaNO2) and ascorbic acid (AsA) has already been shown to promote rat forestomach carcinogenesis, possibly due to nitric oxide generation under acidic conditions. We hypothesized that a similar effect might occur in the esophagus when the luminal pH is decreased by acid reflux. To clarify this possibility, reflux esophagitis model rats (F344 male) were coadministered 0.2% NaNO2 in the drinking water and 1% AsA in the diet. After 32 weeks of the combined treatment, a significant increase in the incidence of epithelial hyperplasias of the lower-middle and lowest parts of the esophagus were observed compared with the basal-diet group, along with exacerbation of dysplasia and extension of the lesions. Additionally, one squamous cell papilloma was found only in the combined-treatment group. Subsequently, we confirmed the enhancing effects of NaNO2 and AsA cotreatment in the rat N-bis(2-hydroxypropyl)nitrosamine-initiated esophageal tumorigenesis model. The incidence of hyperplasia was enhanced in all segments, along with the incidence and multiplicity of squamous cell papillomas in the lowest segment of the esophagus. Thus, the data demonstrate that combined treatment with NaNO2 and AsA exerts promoting effects on rat esophageal carcinogenesis under acid reflux conditions, as in the forestomach. These findings suggest that the risk of excessive intake of a combination of nitrite and antioxidants for esophageal carcinogenesis is appreciable, particularly in patients with reflux esophagitis.
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Affiliation(s)
- Yuichi Kuroiwa
- Division of Pathology, National Institute of Health Sciences, 1-18-1 Kamiyoga, Setagaya-Ku, Tokyo 158-8501, Japan
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Kuroiwa Y, Ishii Y, Umemura T, Kanki K, Mitsumori K, Nishikawa A, Nakazawa H, Hirose M. Combined treatment with green tea catechins and sodium nitrite selectively promotes rat forestomach carcinogenesis after initiation with N-methyl-N'- nitro-N-nitrosoguanidine. Cancer Sci 2007; 98:949-57. [PMID: 17428254 PMCID: PMC11160058 DOI: 10.1111/j.1349-7006.2007.00481.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
Combined treatment with several phenolic antioxidants and sodium nitrite (NaNO(2)) has already shown to enhance rat forestomach carcinogenesis. In the present experiment, effects of green tea catechins (GTC) alone or in combination with NaNO(2) on gastric carcinogenesis were investigated in a rat two-stage carcinogenesis model. Groups of eight, 6-week-old F344 male rats were given 0.01%N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) in their drinking water and 5% NaCl in the diet for 10 weeks for glandular stomach initiation and a single intragastric administration of 100 mg/kg/bodyweight of MNNG at week 9 for forestomach initiation. From week 11, they received either drinking water containing 0.2% NaNO(2) and a diet supplemented with 1% GTC in combination, each individual chemical alone or a basal diet until the end of week 42. In the forestomach, incidences and multiplicities of neoplastic lesions were clearly increased by the combined treatment, in spite of GTC alone suppressing the occurrence of papillomas. In a short-term experiment with similar protocol without MNNG pretreatment, a significant increase of 8-hydroxydeoxyguanosine (8-OHdG) levels in forestomach DNA occurred 24 h after the combined treatment, concomitant with erosion and inflammatory cell infiltration. In an in vitro study, electron spin resonance demonstrated hydroxyl radical formation after incubation of epigallocatechin gallate or epicatechin gallate with the NO generator, NOC-7. Thus, GTC alone showed a weak chemopreventive effect on forestomach carcinogenesis, but in the presence of NaNO(2) it exerted a promotive effect which might involve hydroxyl-radical-associated oxidative DNA damage. However, no influence was exerted in the glandular stomach.
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Affiliation(s)
- Yuichi Kuroiwa
- Division of Pathology, National Institute of Health Sciences, Tokyo 158-8501, Japan
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9
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Kitamura Y, Yamagishi M, Okazaki K, Furukawa F, Imazawa T, Nishikawa A, Hirose M. Lack of enhancing effects of sodium nitrite on 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP)-induced mammary carcinogenesis in female Sprague–Dawley rats. Cancer Lett 2006; 235:69-74. [PMID: 15951105 DOI: 10.1016/j.canlet.2005.04.004] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2005] [Revised: 04/05/2005] [Accepted: 04/06/2005] [Indexed: 11/18/2022]
Abstract
A number of heterocyclic amines (HCAs) have been shown to exert enhanced carcinogenic and mutagenic potential when given simultaneously with sodium nitrite (NaNO(2)). In the present experiment, effects of combined treatment with NaNO(2) and 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP), one of the most prevalent carcinogenic HCAs in the human environment, were assessed with regard to mammary tumor induction in female Sprague-Dawley (SD) rats. Animals at 6 weeks of age were given intragastric doses of 100mg/kg body weight of PhIP twice a week for 4 weeks, during which period 0 or 0.2% NaNO(2) was administered in the drinking water. Control rats received 0.2% NaNO(2) alone for the 4 weeks or non-supplemented water during the entire 48 week experimental period, without carcinogen treatment. The first tumor in the PhIP+NaNO(2) group appeared significantly later than with PhIP alone, and during the experimental period, the incidence, multiplicity and volume of mammary tumors in this group tended towards decreased, although values did not significantly differ at the terminal sacrifice. These results indicate that NaNO(2) does not enhance PhIP-induced rat mammary carcinogenesis, rather possessing some potential for inhibition.
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Affiliation(s)
- Yasuki Kitamura
- Division of Pathology, National Institute of Health Sciences, 1-18-1 Kamiyoga, Tokyo 158-8501, Japan
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Ishii Y, Umemura T, Kanki K, Kuroiwa Y, Nishikawa A, Ito R, Saito K, Nakazawa H, Hirose M. Possible involvement of NO-mediated oxidative stress in induction of rat forestomach damage and cell proliferation by combined treatment with catechol and sodium nitrite. Arch Biochem Biophys 2006; 447:127-35. [PMID: 16530157 DOI: 10.1016/j.abb.2006.01.017] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2005] [Revised: 01/23/2006] [Accepted: 01/24/2006] [Indexed: 11/21/2022]
Abstract
To clarify the mechanisms underlying forestomach carcinogenesis in rats by co-treatment with catechol and sodium nitrite (NaNO2), we investigated the involvement of oxidative stress resulting from reaction of the two compounds. Since generation of semiquinone radical, hydroxyl radical (*OH), and peroxynitrite (ONOO-) arose through the reaction of catechol with NO, we proposed that superoxide resulting from catechol oxidation reacted with excess NO, consequently yielding *OH via ONOO-. Male F344 rats were co-treated with 0.2% catechol in the diet and 0.8% NaNO2 in the drinking water for 2 weeks. Prior to occurrence of histological evidence indicating epithelial injury and hyperplasia, 8-hydroxydeoxyguanosine levels in forestomach epithelium significantly increased from 12 h together with appearance of immunohistochemically nitrotyrosine-positive epithelial cells. There were no remarkable changes in rats given each chemical alone. We conclude that oxidative stress due to NO plays an important role in induction of forestomach epithelial damage, cell proliferation, and thus presumably forestomach carcinogenesis.
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Affiliation(s)
- Yuji Ishii
- Department of Analytical Chemistry, Hoshi University, 2-4-41 Ebara, Shinagawa-ku, Tokyo 142-8501, Japan
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Okazaki K, Ishii Y, Kitamura Y, Maruyama S, Umemura T, Miyauchi M, Yamagishi M, Imazawa T, Nishikawa A, Yoshimura Y, Nakazawa H, Hirose M. Dose-dependent promotion of rat forestomach carcinogenesis by combined treatment with sodium nitrite and ascorbic acid after initiation with N-methyl-N'-nitro-N-nitrosoguanidine: possible contribution of nitric oxide-associated oxidative DNA damage. Cancer Sci 2006; 97:175-82. [PMID: 16542213 PMCID: PMC11158804 DOI: 10.1111/j.1349-7006.2006.00162.x] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
Dose-dependent promotion effects of combined treatment with sodium nitrite (NaNO2) and ascorbic acid (AsA) on gastric carcinogenesis were examined in rats pretreated with N-methyl-N'-nitro-N-nitrosoguanidine (MNNG). Groups of 15 6-week-old F344 male rats were given 0.01% MNNG in their drinking water for 10 weeks to initiate carcinogenesis in the glandular stomach and a single intragastric administration of 100 mg/kg/bodyweight of MNNG by stomach tube at week 9 to initiate carcinogenesis in the forestomach. From week 11, they received either drinking water containing 0.05, 0.1 or 0.2% NaNO2 and a diet supplemented with 0.1 or 0.2% AsA in combination, each individual chemical alone or a basal diet until the end of week 42. In the forestomach, the incidence of hyperplasia was increased dose dependently by the treatment with NaNO2 alone. Incidences of neoplastic lesions were dramatically increased by the combined treatment with NaNO2 and AsA in a dose-dependent manner, but AsA itself had no effect. In the glandular stomach, only toxicity and regenerative changes were increased by the high-dose combination. In a second short-term experiment conducted for sequential observation, necrosis and strong inflammation were found in the forestomach epithelium shortly after commencing combined treatment with 1.0% AsA and 0.2% NaNO2, followed by hyperplasia, whereas there were no obvious effects in the glandular stomach. In addition, after a 4 h treatment with 1.0% AsA and 0.2% NaNO2, a slight increase in the 8-hydroxy-deoxyguanosine levels in the forestomach epithelium was observed by high-performance liquid chromatography and an electrochemical detection system, albeit without statistical significance. In vitro, electron spin resonance demonstrated nitric oxide formation during incubation with NaNO2 and AsA under acidic conditions. Thus, NaNO2 was demonstrated to exert promoter action in the forestomach, with AsA acting as a strong copromoter through cytotoxicity and regenerative cell proliferation, possibly mediated by oxidative DNA damage, but the combined treatment with NaNO2 and AsA had little influence on glandular stomach carcinogenesis.
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Affiliation(s)
- Kazushi Okazaki
- Division of Pathology, National Institute of Health Sciences, 1-18-1 Kamiyoga, Setagaya-Ku, Tokyo 158-8501, Japan
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12
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Kitamura Y, Umemura T, Okazaki K, Kanki K, Imazawa T, Masegi T, Nishikawa A, Hirose M. Enhancing effects of simultaneous treatment with sodium nitrite on 2-amino-3-methylimidazo[4,5-f]quinoline-induced rat liver, colon and Zymbal's gland carcinogenesis after initiation with diethylnitrosamine and 1,2-dimethylhydrazine. Int J Cancer 2006; 118:2399-404. [PMID: 16353153 DOI: 10.1002/ijc.21649] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Combined effects of sodium nitrite (NaNO2) and 2-amino-3-methylimidazo[4,5-f]quinoline (IQ) on liver, colon and Zymbal's gland carcinogenesis were assessed using a rat two-stage carcinogenesis model, with a focus on involvement of oxidative stress. Male 6-week-old F344 rats were given a single intraperitoneal injection of 200 mg/kg of diethylnitrosamine and 4 subcutaneous injections of 40 mg/kg of 1,2-dimethylhydrazine for initiation. Then, they were administered 0 or 300 ppm IQ in the diet or 0, 0.1 or 0.2% NaNO2 in their drinking water for 27 weeks. The treatment with NaNO2+IQ significantly enhanced colon and Zymbal's gland carcinogenesis and tended to enhance hepatocarcinogenesis. The incidence of lung tumors in the IQ-treated groups was significantly increased as compared with the initiation alone group. In a second experiment, male rats were given IQ or NaNO2 under the same conditions as before for 1 week, and at sacrifice, their liver and colon tissue or mucosa were collected for analysis of 8-hydroxydeoxyguanosine (8-OHdG), thiobarbituric acid reactive substances (TBARS), acrolein-modified protein and the bromodeoxyuridine-labeling index (BrdU-LI) (in the colon). In the colon, 8-OHdG, acrolein-modified protein levels and BrdU-LI were significantly increased by the combined treatment. These results indicate that the treatment with NaNO2 enhances IQ-induced colon and Zymbal's gland carcinogenesis in rats and that oxidative DNA damage and lipid peroxidation may partly be involved, especially in the colon. In addition, this experiment showed that IQ can act as a potent lung carcinogen in rats.
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Affiliation(s)
- Yasuki Kitamura
- Division of Pathology, National Institute of Health Sciences, Tokyo 158-8501, and Department of Veterinary Pathology, Faculty of Agriculture, Gifu University, Japan
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Opinion of the Scientific Panel on food additives, flavourings, processing aids and materials in contact with food (AFC) on a request from the Commission related to tertiary-Butylhydroquinone (TBHQ). EFSA J 2004. [DOI: 10.2903/j.efsa.2004.84] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
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Yada H, Hirose M, Tamano S, Kawabe M, Sano M, Takahashi S, Futakuchi M, Miki T, Shirai T. Effects of antioxidant 1-O-hexyl-2,3,5-trimethylhydroquinone or ascorbic acid on carcinogenesis induced by administration of aminopyrine and sodium nitrite in a rat multi-organ carcinogenesis model. Jpn J Cancer Res 2002; 93:1299-307. [PMID: 12495469 PMCID: PMC5926933 DOI: 10.1111/j.1349-7006.2002.tb01238.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
Abstract
The effect of antioxidant, 0.25% 1-O-hexyl-2,3,5-trimethylhydroquinone (HTHQ) or 0.25% ascorbic acid (AsA), on carcinogenesis induced by administration of 0.05% aminopyrine (AP) and 0.05% sodium nitrite (NaNO2), was examined using a rat multi-organ carcinogenesis model. Groups of twenty F344 male rats were treated sequentially with an initiation regimen of N-diethylnitrosamine, N-methyl-N-nitrosourea, N-butyl-N-(4-hydroxybutyl)nitrosamine, N,N'-dimethylhydrazine and 2,2'-dihydroxy-di-n-propylnitrosamine during the first 4 weeks, followed by AP+NaNO2, AP+NaNO2+HTHQ, AP+NaNO2+AsA, NaNO2+HTHQ, NaNO2+AsA, each of the individual chemicals alone or basal diet and tap water as a control. All surviving animals were killed at week 28, and major organs were examined histopathologically for development of preneoplastic and neoplastic lesions. In the AP+NaNO2 group, the incidences of hepatocellular adenomas and hemangiosarcomas were 95% and 35%, respectively. When HTHQ or AsA was simultaneously administered, the incidences decreased to 58% and 11%, or to 80% and 15%, respectively. On the other hand, in the AP+NaNO2 group and the NaNO2-alone group, when HTHQ, but not AsA, was simultaneously administered, the incidence of carcinomas in the forestomach significantly increased. The results suggest that HTHQ can prevent tumor production induced by AP and NaNO2 more effectively than AsA. On the other hand, an enhancing or possible carcinogenic effect of simultaneous administration of HTHQ and NaNO2 only on the forestomach is suggested, while simultaneous treatment with the same dose of AsA and NaNO2 may not be carcinogenic to the forestomach or other organs.
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Affiliation(s)
- Hideaki Yada
- Department of Experimental Oncology and Tumor Biology, Graduate School of Medical Science, Nagoya City University, Mizuho-ku, Nagoya 467-8601, Japan
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15
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Iijima K, Henry E, Moriya A, Wirz A, Kelman AW, McColl KEL. Dietary nitrate generates potentially mutagenic concentrations of nitric oxide at the gastroesophageal junction. Gastroenterology 2002; 122:1248-57. [PMID: 11984511 DOI: 10.1053/gast.2002.32963] [Citation(s) in RCA: 122] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
BACKGROUND & AIMS Twenty-five percent of absorbed dietary nitrate is re-secreted in saliva, and 30% of this is reduced to nitrite by buccal bacteria. When saliva is swallowed, the acidic gastric juice reduces the nitrite to nitric oxide. The aim of this study was to examine the anatomic distribution of nitric oxide generation within the lumen of the upper gastrointestinal tract under basal conditions and after ingesting nitrate equivalent to that in salad portion. METHODS Using custom-made sensors, the dissolved luminal nitric oxide concentration and pH were measured at 1-cm increments for 2 minutes throughout the length of the stomach and distal esophagus in 15 Helicobacter pylori-negative healthy volunteers with and without ingestion of 2 mmol potassium nitrate. Serum nitrate and saliva nitrite concentrations were also monitored. RESULTS The nitrate ingestion increased mean (range) serum nitrate from 30 micromol/L (18-49) to 95 micromol/L (32-152), mean salivary nitrite from 36 micromol/L (19-153) to 252 micromol/L (32-600), and mean peak luminal nitric oxide concentration from 4.7 micromol/L (1.4-7.8) to 23.2 micromol/L (2.1-50) (P < 0.05 for each). After nitrate, the peak nitric oxide concentration occurred in 11 of the 15 (73%) subjects within 1 cm distal to the gastroesophageal pH step-up point. The mean nitric oxide concentration over the 1-cm segment immediately distal to the gastroesophageal pH step-up after nitrate was 7.5 micromol/L (range, 0.5-30.7) and was significantly higher than at all other sites. Nitric oxide concentrations greater than 50 micromol/L were observed at the precise location where neutral esophageal pH fell to acidic gastric pH. CONCLUSIONS Luminal generation of nitric oxide from dietary nitrate via salivary nitrite is maximal at the gastroesophageal junction and cardia. The high concentrations of nitric oxide generated may contribute to the high incidence of mutagenesis and neoplasia at this site.
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Affiliation(s)
- K Iijima
- University Department of Medicine & Therapeutics, Western Infirmary, Glasgow, Scotland
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16
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17
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Miyauchi M, Nakamura H, Furukawa F, Son HY, Nishikawa A, Hirose M. Promoting effects of combined antioxidant and sodium nitrite treatment on forestomach carcinogenesis in rats after initiation with N-methyl-N'-nitro-N-nitrosoguanidine. Cancer Lett 2002; 178:19-24. [PMID: 11849737 DOI: 10.1016/s0304-3835(01)00808-4] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
The effects of sodium nitrite (NaNO2), in combination with one of three antioxidants, tert-butylhydroquinone (TBHQ), alpha-tocopherol (alpha-Toc) and propyl gallate (PG), on N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) stomach carcinogenesis were investigated in F344 rats. Groups of 15 male rats were treated with an intragastric dose of 150 mg/kg body weight of MNNG, and starting 1 week later, were treated with 0.5% TBHQ, 1% alpha-Toc, 1% PG or basal diet with or without 0.2% NaNO2 in their drinking water until they were killed at the end of week 36. Macroscopically, in MNNG-treated animals, combined administration of alpha-Toc or PG with NaNO2 significantly increased the areas and numbers of forestomach nodules as compared with the respective antioxidant alone values. Microscopically, in MNNG-treated animals, treatment with TBHQ significantly increased the incidence and multiplicity of forestomach papillomas as compared with basal diet alone value. Combined administration of alpha-Toc with NaNO2 significantly raised the multiplicity of forestomach papillomas, with a tendency to elevation in the incidence as compared with the group given alpha-Toc alone. Incidences of forestomach moderate and/or severe hyperplasias were significantly higher in the TBHQ or PG plus NaNO2 groups than in the single compound groups. In rats without MNNG treatment, combined treatment of antioxidants with NaNO2 significantly increased the incidences of mild or moderate hyperplasia. In the glandular stomach, although the incidence of atypical hyperplasia showed a non-significant tendency for decrease with TBHQ treatment, additional administration of NaNO2 caused significant increase. These results indicate that co-administration of NaNO2 with alpha-Toc, TBHQ or PG and particularly the first, promotes forestomach carcinogenesis. Concurrent alpha-Toc, TBHQ or PG treatment with NaNO2 is likely to induce forestomach tumors in the long term.
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Affiliation(s)
- Makoto Miyauchi
- Division of Pathology, National Institute of Health Sciences, 1-18-1 Kamiyoga, Setagaya-ku, Tokyo 158-8501, Japan
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18
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Furukawa F, Nishikawa A, Miyauchi M, Nakamura H, Son HY, Yamagishi M, Hirose M. Concurrent administration of fish meal and sodium nitrite does not promote renal carcinogenesis in rats after initiation with N-ethyl-N-hydroxyethylnitrosamine. Cancer Lett 2000; 154:45-51. [PMID: 10799738 DOI: 10.1016/s0304-3835(00)00357-8] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
The modifying effects of concurrent administration of fish meal and sodium nitrite on the development of renal tumors after initiation with N-ethyl-N-hydroxyethylnitrosamine (EHEN) were investigated. A total of 120 male 6-week-old Wistar rats were divided into six groups. Groups 1-3 (30 animals each) were given 1000 ppm EHEN in their drinking water for 3 weeks as an initiation treatment for renal cancer induction and thereafter fed respective diets containing 64, 32, and 8% (original concentration in the basal diet) fish meal, and simultaneously given 0.12% sodium nitrite in the drinking water for 33 weeks. Groups 4-6 (ten animals each) were similarly treated without the prior application of EHEN. At the end of the 37th experimental week, all surviving animals were autopsied and examined histopathologically for the existence of renal proliferative lesions. The incidences of dysplastic lesions, adenomas or adenocarcinomas of the kidney were not significantly different among groups 1-3. No renal proliferative lesions were found in groups 4-6. Chronic nephropathy was slightly but significantly enhanced in the 64 and 32% fish meal-treated groups as compared with group 3. Our results suggest that concurrent administration of fish meal and sodium nitrite does not affect the post-initiation phase of EHEN-induced renal carcinogenesis in the rat.
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Affiliation(s)
- F Furukawa
- Division of Pathology, National Institute of Health Sciences, 1-18-1 Kamiyoga, Setagaya-ku, Tokyo, Japan
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19
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Furukawa F, Nishikawa A, Ishiwata H, Takahashi M, Hayashi Y, Hirose M. Renal carcinogenicity of concurrently administered fish meal and sodium nitrite in F344 rats. Jpn J Cancer Res 2000; 91:139-47. [PMID: 10761700 PMCID: PMC5926328 DOI: 10.1111/j.1349-7006.2000.tb00925.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
The effects of long-term concurrent administration of powdered fish meal and sodium nitrite were examined in F344 rats. A total of 600, 6-week-old rats were divided into 6 male and 6 female groups, each consisting of 50 animals. Rats in groups 1-3 and 7-9 were respectively fed diets supplemented with 64%, 32% and 8% (basal diet) fish meal, and simultaneously given 0.12% sodium nitrite in their drinking water. Groups 4-6 and 10-12 were respectively given 64%, 32% and 8% fish meal and tap water. At the 104th week, all surviving animals were killed and examined histopathologically. Treatment with fish meal dose-dependently increased the incidences and multiplicities of atypical tubules, adenomas and renal cell carcinomas in sodium nitrite-treated males. Females were less susceptible than males for renal tumor induction. In males given the 64% fish meal diet alone, the incidence and multiplicity of atypical tubules were also significantly increased as compared with the 8% fish meal alone case. Nephropathy was apparent in fish meal-treated groups in a clear dose-dependent manner, irrespective of the sodium nitrite treatment, and was more prominent in males than in females. Dimethylnitrosamine was found in the stomach contents after 4-week treatment with 64% fish meal plus 0.12% sodium nitrite, at a level twice that in the 8% fish meal plus 0.12% sodium nitrite group. The results clearly indicate that concurrent administration of fish meal and sodium nitrite induces renal epithelial tumors. Further studies are required to elucidate how nephropathy and nitrosamines produced in stomach contents may contribute to the observed renal tumor induction.
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Affiliation(s)
- F Furukawa
- Division of Pathology, National Institute of Health Sciences, Tokyo.
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20
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Kim JM, Kim JD, Yu R, Kim BS, Shin MK, Han IS. Effects of capsaicin on induction of c-jun proto-oncogene expression in Fisher-344 rats by N-methyl-N'-nitro-N-nitrosoguanidine. Cancer Lett 1999; 142:155-60. [PMID: 10463771 DOI: 10.1016/s0304-3835(99)00154-8] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
N-Methyl-N'-nitro-N-nitrosoguanidine (MNNG) is a potent inducer of cellular stress leading to chromosomal aberrations, point mutations, and cell death. To study the effect of capsaicin on c-jun expression when given with MNNG to rats, Fisher-344 rats that had been administered MNNG were treated with capsaicin in their diet and organs were removed for measuring c-jun transcripts. We show that pre- or post-treatment of capsaicin relative to MNNG administration up- or down-regulates (depending on the organ) c-jun expression in a consistent pattern in most organs. In fact, we found in this study that capsaicin inhibits c-jun induction, stimulated by MNNG, in the spleen, heart, stomach and lung. Since MNNG, a methylating agent, is a powerful carcinogen that is very effective in the induction of c-jun mRNA, the results suggest that capsaicin uptake in the diet could play a role in inhibition of tumorigenesis induced by MNNG.
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Affiliation(s)
- J M Kim
- Department of Food and Nutrition, University of Ulsan, South Korea
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21
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Eynard AR. Is the risk of urinary tract tumorigenesis enhanced by a marginal chronic essential fatty acid deficiency (EFAD)? Nutrition 1998; 14:211-6. [PMID: 9530649 DOI: 10.1016/s0899-9007(97)00426-7] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
A considerable amount of experimental, clinical and epidemiological data indicate that dietary fats play a role in urinary tract tumorigenesis. In rodents, chronic essential fatty acid (EFA) deficiency seems to induce both urolithiasis and transitional hyperplasias, followed by a tendency for tumorigenesis of the urinary passages. High intake of saturated fats or non-EFAs, conditions that may induce EFA deficiency (EFAD) increase the risk of bladder cancer in case-control studies. In other cell populations, EFAs are beneficial as preventive and therapeutic nutrients for the treatment of cancer. Thus, it is reasonable to assume that abnormal metabolism and/or nutritional deprivation of EFA, by inducing a chronic or a subclinical EFA deficiency, may enhance the risk of urothelial tumorigenesis.
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Affiliation(s)
- A R Eynard
- Instituto de Biología Celular, Facultad de Ciencias Médicas, Córdoba, Argentina
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22
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Kitano M, Takada N, Chen T, Ito H, Nomura T, Tsuda H, Wild CP, Fukushima S. Carcinogenicity of methylurea or morpholine in combination with sodium nitrite in rat multi-organ carcinogenesis bioassay. Jpn J Cancer Res 1997; 88:797-806. [PMID: 9369926 PMCID: PMC5921515 DOI: 10.1111/j.1349-7006.1997.tb00454.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
For carcinogenic risk assessment of combinations of N-nitroso precursors in man, the effects of feeding methylurea (MU) or morpholine (Mor) plus sodium nitrite (NaNO2) were investigated using a multi-organ carcinogenesis model. In experiment 1, to initiate multiple organs, groups of 10 or 20 male F344 rats were treated with 6 carcinogens targeting different organs. Starting a week after completion of this initiation phase, animals were given 0.1% MU or 0.5% Mor in their food and/or 0.15% NaNO2 in their drinking water for 23 weeks. The induction of tumors and/or preneoplastic lesions in the forestomach and esophagus was significantly increased in the group receiving MU plus NaNO2. The numbers and areas of liver glutathione S-transferase placental form (GST-P)-positive foci were significantly elevated with MU or Mor plus NaNO2. Experiment 2 was conducted to assess formation of N-nitroso compounds in the stomach, and to detect DNA adduct generation in target organs by immunohistochemical staining. Groups of 5 or 14 animals were starved overnight, then given 0.4% MU or 2.0% Mor in the diet, or basal diet alone for 1 h. Then NaNO2 or distilled water was given intragastrically. The mean gastric N-methyl-N-nitrosourea yield in the MU plus NaNO2 group was 7700 micrograms at 2 h after combined administration. The mean N-nitrosomorpholine yield in the group given Mor plus NaNO2 was 6720 micrograms. Immunohistochemically, N7-methyldeoxyguanosine-positive nuclei were evident in the forestomach epithelium at 8 h after the combination treatment with MU plus NaNO2.
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Affiliation(s)
- M Kitano
- First Department of Pathology, Osaka City University Medical School
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23
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Abstract
Incubation of human lymphocytes, neonatal fibroblasts, and Molt-4 cells (T-cell leukemia cell line) with sodium ascorbate for 1 h resulted in a concentration-dependent increase in DNA single-strand breaks as assayed by an alkaline microgel electrophoresis technique. Fibroblasts and Molt-4 cells were significantly more sensitive than lymphocytes to the induction of DNA single-strand breaks by 25, 50, and 100 microM concentrations of sodium ascorbate. Significant cell loss was observed in Molt-4, but not in lymphocyte and fibroblast cultures, after 4 h of incubation in 50 microM of sodium ascorbate, a concentration similar to the plasma level of ascorbic acid in humans.
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Affiliation(s)
- N P Singh
- Bioelectromagnetics Research Laboratory, College of Medicine, University of Washington, Seattle 98195, USA
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24
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Eynard AR, Manzur T, Moyano A, Quiroga P, Muñoz S, Silva SM. Dietary deficiency or enrichment of essential fatty acids modulates tumorigenesis in the whole body of cobalt-60-irradiated mice. Prostaglandins Leukot Essent Fatty Acids 1997; 56:239-44. [PMID: 9089806 DOI: 10.1016/s0952-3278(97)90542-1] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
The effect of dietary polyunsaturated fatty acids (PUFAs) on whole body-induced tumorigenesis was assayed in mice fed on essential fatty acid sufficient (EFAS) or essential fatty acid deficient (EFAD) diets following cobalt-60 irradiation. Four groups of mice were maintained, one on a control stock diet and three on experimental diets: a) without added fat (fat free, FF); b) containing 5% olein (O), rich in n-9; and c) containing 5% corn oil, rich in n-6 EFA (CO). Only mice fed on FF or O diets showed clinical and biochemical signs of EFAD. Total incidence of tumors showed an increase in FF (P < 0.02) and O (P < 0.03) mice. Tumors developed mostly in the liver in each of the EFAD groups (P < 0.001). Slight promoting activity on lung tumorigenesis was recorded in the CO group when this parameter was compared in EFAD and EFA sufficient mice. It may be concluded that, when a tumor initiator injures the body as a whole, EFAD, achieved either through a fat-free or an oleic-supplemented diet, behaves as a general promoting condition for tumorigenesis. The borderline tumorigenic effect of n-6 corn oil on the lungs suggests that this effect, when present, is target specific.
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Affiliation(s)
- A R Eynard
- Instituto Biologia Celular (FCM-UNC), CONICET, Cordoba, Argentina
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25
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Abstract
Many experimental, clinical and epidemiological data indicate that n-3 and n-6 essential fatty acids are therapeutic nutrients which may delay the development as well as improve the course of cancer. The present hypothesis correlates well with these data and it is proposed that chronic essential fatty acid deficiency, when coexisting with chronic hyperproliferative states (hyperplasias) and de-differentiation (dysplasias) both acting synergistically, may constitute a pro-tumorigenic situation. Evidence showing that, indeed, these hyperproliferative states are consistently reported in essential fatty acid deficiency in many species, including humans, in malpighian layers of skin and the upper alimentary and urinary tracts, among others, is discussed.
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Affiliation(s)
- A R Eynard
- Instituto de Biología Celular, Facultad de Ciencias Médicas, Córdoba, Argentina
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26
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Abstract
A literature review was made to critically evaluate the ability of ascorbic acid to modulate the incidence of gastrointestinal cancer. A comparison of preclinical, clinical, and epidemiological studies indicated that evidence for ascorbic acid as an inhibitor of carcinogenesis is stronger with regard to gastric cancer and weaker with regard to esophageal and colon/rectal cancer. Insufficient evidence currently exists regarding the oral cavity and the use of ascorbic acid in precancerous conditions such as polyposis and leukoplakia.
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Affiliation(s)
- M Cohen
- Scientific Information Services, Hoffmann-La Roche, Nutley, NJ 07110, USA
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27
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Silva RA, Muñoz SE, Guzmán CA, Eynard AR, Evnard AR. Effects of dietary n-3, n-6 and n-9 polyunsaturated fatty acids on benzo(a)pyrene-induced forestomach tumorigenesis in C57BL6J mice. Prostaglandins Leukot Essent Fatty Acids 1995; 53:273-7. [PMID: 8577781 DOI: 10.1016/0952-3278(95)90127-2] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
The modulating effect of dietary polyunsaturated fatty acids (PUFAs) on benzo(a)pyrene-induced forestomach tumorigenesis was assayed in mice fed with corn oil (CO), olein (O), Zizyphus mistol seed oil (MO), cod liver oil (CLO), and mixed fat (Stock diet). The fatty acid composition of liver lipids correlated well with the fatty acid composition of each diet. Only mice fed the O diet showed biochemical and clinical evidences of essential fatty acid deficiency (EFAD). Only 3 animals developed well-differentiated invading squamous cell carcinomas in the O group. The papilloma incidence was reduced in MO and CLO with respect to the O group. Forestomach papillomatosis was increased in mice fed an n-9 enriched diet in comparison to stock and CO groups. In comparison with stock mice, the frequency of multiple epidermoidal hyperplasia (MEH) was significantly decreased in the CLO group. Animals fed n-3 enriched diets (MO and CLO) showed significant antipromoting effect. These findings indicate that dietary fat can modulate tumorigenesis initiated in mouse forestomach by benzo(a)pyrene. In addition, the lack of action of an n-6 fatty acid-enriched diet in our experimental model suggests that the effect of PUFAs on tumorigenesis has target-tissue specificity. Mistol seed oil might be of potential value as a natural vegetable antipromoter nutrient.
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Affiliation(s)
- R A Silva
- Cátedra de Histologia, Instituto de Biologia Celular (FCM), Universidad Nacional de Córdoba-CONICET, Argentina
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28
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Xiang YY, Wang DY, Tanaka M, Igarashi H, Kamo T, Shen Q, Sugimura H, Kino I. Efficient and specific induction of esophageal tumors in rats by precursors of N-nitrososarcosine ethyl ester. Pathol Int 1995; 45:415-21. [PMID: 7581932 DOI: 10.1111/j.1440-1827.1995.tb03478.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Cancers and precancerous lesions of the esophagus were efficiently induced in rats by the simulation of a clinico-epidemiological setting; that is, the administration of precursors of nitrosamine. Six week old non-inbred male Wistar rats were given 2g/kg bodyweight of sarcosine ethyl ester hydrochloride (SEEH) and concurrently 0.3g/kg bodyweight of sodium nitrite (NaNO2), precursors of N-nitrososarcosine ethyl ester (NSEE), in 2% sucrose as drinking water. Group 1 received the precursors twice a week for 6 weeks followed by 8 weeks observation, and group 2, once every 3 days for 7 weeks followed by 26 weeks observation. At the end of treatment, no tumor had developed in the esophagus of rats in group 1, but the [3H]-thymidine labeling indices in both basal and superficial layer cells were higher than in the control group. On subsequent observation, papillomas appeared in group 1 (33.3%), and carcinomas in group 2 (33.3%), within 4 weeks. The tumors induced in group 1 were mostly papillomas and rarely carcinomas. When the observation was prolonged in group 2, 100% of the animals had cancer in week 20. The pathological changes of the lesions paralleled the sequential development of human squamous cell carcinoma of the esophagus. Our system has the advantages in that papillomas and cancers can be induced in rats in a short time and the agents used are less toxic than preformed nitrosamines administered previously by gastric intubation. It would serve as a useful experimental tool to study premalignant lesions and cancers of the esophagus.
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Affiliation(s)
- Y Y Xiang
- First Department of Pathology, Hamamatsu University School of Medicine, Japan
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