| 1. |
- Gradecka-Meesters, Dobroslawa, et al.
(author)
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Assessment of the protective effects of selected dietary anticarcinogens against DNA damage and cytogenetic effects induced by benzo[a]pyrene in C57BL/6J mice
- 2011
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In: Food and Chemical Toxicology. - : Elsevier BV. - 0278-6915 .- 1873-6351. ; 49:8, s. 1674-1683
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Journal article (peer-reviewed)abstract
- The protective action in C57BL/6J mice from orally administered ellagic acid (EA), benzyl isothiocyanate (BITC), an extract of epigallocatechins (Tegreen (R)) as well as chlorophyllin (CHL) against benzo[a]pyrene (B[a]P)-induced DNA damage and cytogenetic effects was investigated. In pilot experiment the comet assay indicated protective effects for all compounds, while such activity was confined to EA and CH with respect to B[a]P-DNA adducts and micronuclei. EA and CH were chosen for the main study where the levels of DNA adducts in liver after injection of 30 mg B[a]P/kg b.w. did not differ from those found for animals exposed to B[a]P and treated with the protective substances. In leukocytes no significant protective effect of CHL was detected while a 2-fold increase of adduct concentrations was observed after co-administration of EA. In the comet assay CHL or EA caused a 3-fold decrease of SSB, and a 2-fold decrease of FPG sites in comparison to animals treated with B[a]P. CHL or EA showed a significant protective effect against B[a]P-induced MN in polychromatic erythrocytes in bone marrow. In contrast, flow cytometry measurements in peripheral blood indicated the MN frequency after treatment with CHL or EA almost twice as high as that recorded for B[a]P alone.
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| 2. |
- Ringerike, Tove, et al.
(author)
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Detection of immunotoxicity using T-cell based cytokine reporter cell lines ("Cell Chip").
- 2005
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In: Toxicology. - : Elsevier BV. - 0300-483X .- 1879-3185. ; 206:2, s. 257-72
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Journal article (peer-reviewed)abstract
- Safety assessment of chemicals and drugs is an important regulatory issue. The evaluation of potential adverse effects of compounds on the immune system depends today on animal experiments. An increasing demand, however, exists for in vitro alternatives. Cytokine measurement is a promising tool to evaluate chemical exposure effects on the immune system. Fortunately, this type of measurement can be performed in conjunction with in vitro exposure models. We have taken these considerations as the starting point to develop an in vitro method to efficiently screen compounds for potential immunotoxicity. The T-cell lymphoma cell line EL-4 was transfected with the regulatory sequences of interleukin (IL)-2, IL-4, IL-10, interferon (IFN)-gamma or actin fused to the gene for enhanced green fluorescent protein (EGFP) in either a stabile or a destabilised form. Consequently, changes in fluorescence intensity represent changes in cytokine expression with one cell line per cytokine. We used this prototype "Cell Chip" to test, by means of flow cytometry, the immunomodulatory potential of 13 substances and were able to detect changes in cytokine expression in 12 cases (successful for cyclosporine, rapamycin, pentamidine, thalidomide, bis(tri-n-butyltin)oxide, house dust mite allergen (Der p I), 1-chloro-2,4-dinitrobenzene, benzocaine, tolylene 2,4-diisocyanate, potassium tetrachloroplatinate, sodium dodecyl sulphate and mercuric chloride; unsuccessful for penicillin G). In conclusion, this approach seems promising for in vitro screening for potential immunotoxicity, especially when additional cell lines besides T-cells are included.
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| 3. |
- Ullerås, Erik, et al.
(author)
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Development of the "Cell Chip" : a new in vitro alternative technique for immunotoxicity testing.
- 2005
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In: Toxicology. - : Elsevier BV. - 0300-483X .- 1879-3185. ; 206:2, s. 245-56
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Journal article (peer-reviewed)abstract
- Predictive testing of immunotoxicity associated with chemical compounds is complicated and cannot be accomplished with a single test. As most of the existing tests for immunotoxicity employ experimental animals, there is an increasing need for alternative tests in vitro. We have developed a new system for in vitro immunotoxicity testing, which employs changes in cytokine expression observed in vitro as an endpoint indicating potential for perturbation of the immune system in vivo. This system named "fluorescent cell chip" (FCC) is based on a number of genetically modified cell lines that regulate the expression of a transgene coding for fluorescent protein enhanced green fluorescent protein (EGFP) in a similar way as they regulate expression of IL-1beta, IL-2, IL-4, IFN-gamma, IL-10, TNF-alpha, and beta-actin. Morphological and functional features of selected cell lines expressing EGFP under the control of cytokine promotors were compared with maternal cell lines and this comparison showed that critical functional features of the maternal cell lines were preserved in EGFP expressing cells. Two chemicals with known immunotoxic activities, cyclosporine A and potassium tetrachloro-platinate(II), mediated compound-specific pattern of inhibition and activation of reporter gene expression. Thus, the "fluorescent cell chip" has demonstrated potential for application as a predictive screening test for immunomodulatory activities of chemicals. The major advantage of this approach is the possibility to apply this test in high throughput screening of high number of compounds for their well defined biological activity.
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