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Journal ArticleDOI

Modifying role of Phyllanthus emblica and ascorbic acid against nickel clastogenicity in mice.

26 Jul 1991-Cancer Letters (Elsevier)-Vol. 59, Iss: 1, pp 9-18
TL;DR: Aqueous extract of edible dried fruits of Phyllanthus emblica was fed to Mus musculus for seven consecutive days prior to treatment with different doses of nickel chloride, finding the greater efficacy of the fruit extract could be due to the interaction of its various natural components rather than to any single constituent.

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Abstract: Nickel, a major environmental pollutant is known for its clastogenic and carcinogenic potential. Dietary inhibitors of mutagenesis and carcinogenesis are of particular importance since they may have a role in cancer prevention. In the present investigation, aqueous extract of edible dried fruits of Phyllanthus emblica, a well known medicinal plant, was fed to Mus musculus for seven consecutive days prior to treatment with different doses of nickel chloride (10, 20 and 40 mg/kg body wt.); the fruit extract significantly reduced the frequency of CA/cell, the percentage of aberrant cells and the frequency of micronuclei induced by all doses of nickel in the bone marrow cells of mice. Ascorbic acid, a major constituent of the fruit, fed for 7 consecutive days in equivalent concentration as that present in the fruit, however, could only alleviate the cytotoxic effects induced by low doses of nickel; at the higher doses it was ineffective. The greater efficacy of the fruit extract could be due to the interaction of its various natural components rather than to any single constituent. The study assumes importance in view of the widespread human exposure to nickel compounds.

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Topics: Dried fruit (60%), Ascorbic acid (57%), Phyllanthus emblica (56%)
Citations
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Journal ArticleDOI
Paolo Scartezzini1, Ester Speroni1Institutions (1)
TL;DR: Seven plants contain antioxidant principles, that can explain and justify their use in traditional medicine in the past as well as the present, and are viewed for their historical, etymological, morphological, phytochemical and pharmacological aspects.

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Abstract: A lot of medicinal plants, traditionally used for thousands of years, are present in a group of herbal preparations of the Indian traditional health care system (Ayurveda) named Rasayana proposed for their interesting antioxidant activities. Among the medicinal plants used in ayurvedic Rasayana for their therapeutic action, some of these have been throughly investigated. In the present paper seven plants (Emblica officinalis L., Curcuma longa L., Mangifera indica L., Momordica charantia L., Santalum album L., Swertia chirata Buch-Ham, Withania somnifera (L.) Dunal) are viewed for their historical, etymological, morphological, phytochemical and pharmacological aspects. The plants described contain antioxidant principles, that can explain and justify their use in traditional medicine in the past as well as the present. In order to identify the plants with antioxidant activity in Ayurveda, a formulation of some rasayanas with well defined antioxidant properties has been examinated. For this purpose, we have considered Sharma's work on the preparation MAK4, MAK5, MA631, MA 471, MA Raja's Cup, MA Student Rasayana, MA Ladies Rasayana.

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747 citations


01 Aug 2005-

355 citations


Cites background from "Modifying role of Phyllanthus embli..."

  • ...The nickel-induced DNA damage has resulted in the formation of chromosomal aberrations (Conway and Costa 1989; Dhir et al. 1991; Larramendy et al. 1981; Lechner et al. 1984; Sen and Costa 1986b; Sen et al. 1987; Waksvcik and Boysen 1982) that could result in deletion of senescence or tumor suppressor genes....

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  • ...Chromosome gaps or chromosome aberrations have been reported in lymphocytes from nickel refinery workers (Waksvik and Boysen 1982), mouse bone marrow cells following intraperitoneal injection (Dhir et al. 1991), and in in vitro assays using hamster cells (Conway and Costa 1989; Larramendy et al....

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Journal Article
01 Jan 1997-Mutation Research
TL;DR: Structural-activity relationship analysis suggested that the micronucleus assay is more sensitive to the genetic toxicity of some classes of chemicals than to those carcinogens with stronger evidence human carcinogenicity.

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263 citations


Journal ArticleDOI
Takeshi Morita, Norihide Asano1, Takumi Awogi2, Yu F. Sasaki  +7 moreInstitutions (3)
Abstract: To assess the correlation between micronucleus induction and human carcinogenicity, the rodent micronucleus assay was performed on known and potential human carcinogens in the 6th MMS/CSGMT collaborative study Approximately 100 commercially available chemicals and chemical groups on which there was little or no micronucleus assay data were selected from IARC (International Agency for Research on Cancer) Groups 1 (human carcinogen), 2A (probable human carcinogen) and 2B (possible human carcinogen) As minimum requirements for the collaborative study, 5 male mice were treated by intraperitoneal injection or oral gavage once or twice with each chemical at three dose levels, and bone marrow and/or peripheral blood was analyzed Five positives and 2 inconclusives out of 13 Group 1 chemicals, 7 positives and 5 inconclusives of 23 Group 2A chemicals, and 26 positives and 6 inconclusives of 67 Group 2B chemicals were found Such low positive rates were not surprising because of a test chemical selection bias, and we excluded well-known micronucleus inducers The overall evaluation of the rodent micronucleus assay was based on the present data combined with published data on the IARC carcinogens After merging, the positive rates for Groups 1, 2A and 2B were 686, 545 and 456%, respectively Structure-activity relationship analysis suggested that the micronucleus assay is more sensitive to the genetic toxicity of some classes of chemicals Those to which it is sensitive consist of (1) aziridines and bis(2-chloroethyl) compounds; (2) alkyl sulfonate and sulfates; (3) acyl-type N-nitroso compounds; (4) hydrazines; (5) aminobiphenyl and benzidine derivatives; and (6) azo compounds Those to which it is less sensitive consist of (1) dialkyl type N-nitroso compounds; (2) silica and metals and their compounds; (3) aromatic amines without other functional groups; (4) halogenated compounds; and (5) steroids and other hormones After incorporation of structure-activity relationship information, the positive rates of the rodent micronucleus assay became 905, 652 and 600% for IARC Groups 1, 2A and 2B, respectively Noteworthy was the tendency of the test to be more sensitive to those carcinogens with stronger evidence human carcinogenicity

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241 citations


Journal ArticleDOI
18 Mar 2011-Mutation Research
TL;DR: There is no convincing evidence that any genotoxic rodent carcinogens or in vivo genotoxins would remain undetected in an in vitro test battery consisting of Ames+MNvit.

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Abstract: In vitro genotoxicity testing needs to include tests in both bacterial and mammalian cells, and be able to detect gene mutations, chromosomal damage and aneuploidy. This may be achieved by a combination of the Ames test (detects gene mutations) and the in vitro micronucleus test (MNvit), since the latter detects both chromosomal aberrations and aneuploidy. In this paper we therefore present an analysis of an existing database of rodent carcinogens and a new database of in vivo genotoxins in terms of the in vitro genotoxicity tests needed to detect their in vivo activity. Published in vitro data from at least one test system (most were from the Ames test) were available for 557 carcinogens and 405 in vivo genotoxins. Because there are fewer publications on the MNvit than for other mammalian cell tests, and because the concordance between the MNvit and the in vitro chromosomal aberration (CAvit) test is so high for clastogenic activity, positive results in the CAvit test were taken as indicative of a positive result in the MNvit where there were no, or only inadequate data for the latter. Also, because Hprt and Tk loci both detect gene-mutation activity, a positive Hprt test was taken as indicative of a mouse-lymphoma Tk assay (MLA)-positive, where there were no data for the latter. Almost all of the 962 rodent carcinogens and in vivo genotoxins were detected by an in vitro battery comprising Ames+MNvit. An additional 11 carcinogens and six in vivo genotoxins would apparently be detected by the MLA, but many of these had not been tested in the MNvit or CAvit tests. Only four chemicals emerge as potentially being more readily detected in MLA than in Ames+MNvit--benzyl acetate, toluene, morphine and thiabendazole--and none of these are convincing cases to argue for the inclusion of the MLA in addition to Ames+MNvit. Thus, there is no convincing evidence that any genotoxic rodent carcinogens or in vivo genotoxins would remain undetected in an in vitro test battery consisting of Ames+MNvit.

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187 citations


Additional excerpts

  • ...Nickel chloride Nickel chloride hexhydrate 7718-54-9 7791-20-0 E + [985]; − TC [370,474,986, 987]; I [988]; − [989] + [990, 991]; gpt [992]; HPRT [388,993] + [392,785] + + [994–999]; Weak + [1000] E + [1001,1002]; − [120,1003] + [1002] + [1004,1005]...

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  • ...[1002] H....

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References
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Journal ArticleDOI
Bruce N. Ames1Institutions (1)
23 Sep 1983-Science
TL;DR: Dietary intake of natural antioxidants could be an important aspect of the body's defense mechanism against these agents of cancer and other age-related diseases.

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Abstract: The human diet contains a great variety of natural mutagens and carcinogens, as well as many natural antimutagens and anticarcinogens. Many of these mutagens and carcinogens may act through the generation of oxygen radicals. Oxygen radicals may also play a major role as endogenous initiators of degenerative processes, such as DNA damage and mutation (and promotion), that may be related to cancer, heart disease, and aging. Dietary intake of natural antioxidants could be an important aspect of the body’s defense mechanism against these agents. Many antioxidants are being identified as anticarcinogens. Characterizing and optimizing such defense systems may be an important part of a strategy of minimizing cancer and other age-related diseases.

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2,892 citations


Book ChapterDOI
W. Schmid1Institutions (1)
01 Jan 1976-
TL;DR: Micronuclei originate from chromatin which for different reasons has been lagging in anaphase, and in the course of telophase this material is included into one or the other daughter cell where it either can fuse with the main nucleus or form one or several secondary nuclei.

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Abstract: Micronuclei originate from chromatin which for different reasons has been lagging in anaphase (Fig. la-d). In the course of telophase this material is included into one or the other daughter cell where it either can fuse with the main nucleus or form one or several secondary nuclei. These are, as a rule, considerably smaller than the principal nucleus and are therefore called micronuclei. Lagging has two main causes: chromosome breakage and malfunction of the spindle apparatus. In the first case the lagging elements are acentric chromosome fragments and di- or multicentrics connected by bridges, and in the second case they consist of entire chromosomes.

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604 citations




Journal ArticleDOI
01 Dec 1988-Mutation Research
TL;DR: In this chapter, inhibitors of mutagenesis and carcinogenesis that can arise as components of diet have been reviewed and most of the inhibitors have been demonstrated to be effective against a specific class of mutagens or carcinogens.

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Abstract: Dietary inhibitors of mutagenesis and carcinogenesis are of particular interest because they may be useful for human cancer prevention. Several mutagenesis inhibitors have been demonstrated to be carcinogenesis inhibitors also, e.g., ellagic acid, palmitoleic acid, and N-acetylcysteine. This means that the search for mutagenesis inhibitors may be useful for discovering anticarcinogenic agents. Many mutagenesis inhibitors have been discovered by the use of short-term assays, particularly the Ames Salmonella test. This simple in vitro system has provided opportunities to elucidate the mechanisms of inhibition. The elucidation of the mechanism may allow us to infer the possible anticarcinogenic activity of the reagent. In this chapter, inhibitors of mutagenesis and carcinogenesis that can arise as components of diet have been reviewed. Most of the inhibitors have been demonstrated to be effective against a specific class of mutagens or carcinogens. Therefore, it may be argued that these inhibitors are antagonistic only to those particular agents. Here again, understanding of the mechanisms of these inhibitions is necessary for the assessment. Dietary inhibitors reviewed in this article include: (1) as inhibitors of mutagenesis: porphyllins, fatty acids, vitamins, polyphenols, and sulfhydryl compounds, (2) as inhibitors of carcinogenesis: vitamins A, E and C, ellagic acid, sulfhydryl compounds, fats, selenium, calcium, and fiber. Further studies in this area of science appear to help establish the recipe of a healthy diet.

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307 citations