• Toxicological Research
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• v.18 no.2
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• pp.175-181
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• 2002

Allergic contact dermatitis (skin sensitization) may be caused by a wide variety of chemicals. A murine local lymph node assay (LLNA) has been developed as an alternative to guinea pig models for assessing the contact sensitization potential of chemical. This study was carried out to evaluate the skin sensitization potential for chemicals in Balb/c mice by LLNA. Contact allergen, dinitrochlorobenzene (DNCB), respiratory allergen, toluene diisocyanate (TDI) and a weak allergen, $\alpha$-hexlycinnamaldehyde (HCA) were wed as positive chemicals and irritant, sodium lauryl sulfate(SLS) also wed as a reference chemical in this study. The weights of lymph node in the mice treated with DNCB, TDI, and HCA were increased compared to vehicle control. There was a significant increase in lymph node weight of mice treated with high concentration of SLS compared to vehicle control. The stimulation index (SI) of Lymph node cell in the mice treated with DNCB, TDI, and HCA revealed over three-fold increase compared to vehicle control by $3^H$-thymidine uptake. All allergens correctly identified in this LLNA study wing Balb/c mice. These results suggest that LLNA wing Balb/c mice could be a useful method for screening the allergenic potential of chemicals. The expression of IL-2 mRNA was slightly increased in draining auricular lymph node cell of the mice treated with TDI and HCA by RT-PCR. However the IL-2 levels in DNCB and SLS of treated animals were not significantly changed.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.22 no.2
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• pp.201-210
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• 1996

Predictive tests for the identification of contact sensitizing chemicals have been developed. We measured the sensitization potential with three predictive tests, the in vitro and the in vivo Local Lymph Node Assay(LLNA), ELISA to detect interferon-gamma(IFN-${\gamma}$) from supernatant and flow cytometry to detect change of cell surface proteins, using draining lymph nodes of mice. BALB/c mice were exposed to various chemicals or vehicles on the ears daily for 3 consecutive days in all experiments. With some exceptions of propyl paraben, neomycin sulfate, the in vivo LLNA was able to detect the sensitizing capacity of test chemicals and was more sensitive than the in vitro LLNA for chemicals used in the present study. In another experiment, contact sensitivity was assessed by the ELISA to detect IFN-Υ from the supernatants of the cultured LNCs after sensitization with chemicals. There was a good correlation between the LLNA and the IFN-Υ production for test chemicals. We also examined the change of cell surface proteins on LNCs after sensitization by flow cytometry for some cell adhesion molecules(ICAM-1, E-cadherine, B7 molecule), T cell markers(CD3, CD4, CD8, T$\alpha$$\beta$,T${\gamma}$$\delta$) and B cell markers(LR1, CD45R, I-Ad). The number of ICAM-1 positive cells and B cells in LNCs were increased after sensitization with DNCB, TNCB, isoeugenol and 25%, 50% cinnamic aldehyde compared with that of vehicle as a control. In conclusion, the in vivo LLNA could provide more sensitive screening test for moderate to strong sensitizers and some weak sensitizers including cosmetic raw materials than the in vitro LLNA. The production of IFN-Υ by allergen-activated LNCs might be a values indicators without radioisotopes for the identification of contact allergens. Detection of allergens by testing the increase of ICAM-1 positive cells and B cells in LNCs by flow cytometry might be used as a test method to detect allergens.

• Toxicological Research
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• v.19 no.4
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• pp.285-291
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• 2003

The use of skin whitening agents has been recently increased in various kinds of cosmetic products, although there were some reports that whitening agents might cause allergic contact dermatitis. A murine local lymph node assay (LLNA) has been developed as an alternative to guinea pigs for contact sensitization potential. This study was carried out to investigate the skin sensitization potential of three whitening agents, arbutin, azelaic acid, and kojic acid, by LLNA using a non-radiois-topic endpoint. Female Balb/c mice were exposed topically to a weak allergen, $\alpha$-hexylcinnamalde-hyde (HCA), and three whitening agents following LLNA protocol. Lymph node (LN) weight and cell proliferation in ears and auricular lymph node using bromodeoxyuridine (BrdU) immunohistochemistry were evaluated. LN weights were significantly increased at the HCA group compared to the vehicle control. A weak allergen, HCA elicited 3-fold or greater increase in cell proliferation of lymph nodes as well as increase in cell proliferation of ear as measured by BrdU immunohistochemistry. However, in the case of skin whitening agent groups, there were no significant changes in LN weight and cell proliferation in the ear and lymph node of mice treated with 5, 10 and 20% of three whitening agents compared to the vehicle control. These results show that these three skin whitening agents may not have contact sensitization potentials at tested concentrations in Balb/c mice by LLNA.

• Proceedings of the Korean Society of Toxicology Conference
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• 2003.05a
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• pp.80-80
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• 2003

The use of skin whitening agents have been recently increased in various kinds of cosmetic products, although there were reports that whitening agents might cause allergic contact dermatitis. A murine local lymph node assay (LLNA) has been developed as an alternative to guinea pigs for contact sensitization potential. This study was carried out to investigate the skin sensitization potential of three whitening agents, kojic acid, arbutin, azelaic acid, by LLNA using a non-radioistopic endpoint.(omitted)

• Proceedings of the Korean Society of Toxicology Conference
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• 2001.10a
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• pp.193-193
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• 2001

A murine local lymph node assay (LLNA) has been developed as an alternative to guinea pig models for contact sensitization potential. However, a disadvantage of the LLNA is the need for the use of radioactive material. In this study, we aimed to investigate the development of non-radio isotopic endpoint for LLNA using immunohistochemistry.(omitted)

• Proceedings of the Korean Society of Toxicology Conference
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• 2001.10a
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• pp.194-194
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• 2001

Preclinical test methods for allergenic potential chemicals has been widely used to assess human risks and has been developed. Recently, the murine local lymph node assay (LLNA) has been proposed as a prospective method to identify contact allergens and to replace conventional the guinea pig maximization test (GPMT). The objective of this study was to establish LLNA and to evaluate allergenicity of chemicals by LLNA. (omitted)

• Proceedings of the Korean Society of Toxicology Conference
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• 2003.10b
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• pp.124-124
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• 2003

A murine local lymph node assay(LLNA) has been developed as an alternative method to guinea pig maximization test for contact sensitization potential. This study was carried out to investigate the potential use of cytokine producing cells to discriminate between allergens and irritant in the LLNA.(omitted)

• Proceedings of the Korean Society of Toxicology Conference
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• 2002.11b
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• pp.185-185
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• 2002

A murine local lymph node assay (LLNA) has been developed as an alternative test to guinea pig maximization test. The disadvantage of LLNA is the need for the use of radioactive material. In this study, we aimed to investigate the development of non-radio isotopic endpoint for local lymph node assay in Balb/c mice using Enzyme-linked immunosorbent assay (ELISA) based on Bromodeoxyuridine (BrdU) incorporation.(omitted)

• Toxicological Research
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• v.19 no.2
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• pp.133-139
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• 2003

Allergic contact dermatitis may be caused by a wide variety of chemicals. A murine local lymph node assay (LLNA) has been developed as an alternative to guinea pig models for assessing the contact sensitization potential of chemical. However, there is a need to develop a nonradioisotopic endpoint for the LLNA, because of the radioisotopic method's requiring the use of special facilities. In this study, we investigated the development of a nonradioisotopic endpoint for LLNA using ELISA (enzyme-linked immunosorbent assay). Female Balb/c mice were treated by the topical application on the dorsum of both ears with four different strong sensitizers, 2,4-dinitrochlorobenzene (DNCB), oxazolone (OXZ), toluene diisocyanate (TDI), and trimellitic anhydride (TMA), and a strong irritant, sodium lauryl sulfate (SLS), once daily for three consecutive days. The proliferation of cells in the auricular Iymph node was analyzed by means of the labelling index (Ll) of bromodeoxyuridine (BrdU) incorporation into cells. The weights of the Iymph nodes in the mice treated with allergens, DNCB, OXZ, TDl and TMA were increased compared to the vehicle control. The stimulation index (Sl) of mice treated with DNCB, OXZ, TDl, and TMA was over three-fold increase compared to the vehicle control. However, the S1 of mice exposed to SLS was not significantly increased compared to the vehicle control, while the lymph node weight of SLS was significantly increased. These results suggest that the LLNA modified endpoint using ELISA based on BrdU incorporation could provide a useful method of screening for irritants and allergens.

• Proceedings of the Korea Environmental Mutagen Society Conference
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• 2003.10a
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• pp.124-124
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• 2003