ABSTRACT
Objective To establish a rapid modified Local lymph node assay ( LLNA) for the sensitization and irritancy potential of chemicals, and evaluate cosmetics products. Methods 3 kinds of chemicals ( 2 , 4-Dinitrochlorobenzene ( DNCB) , Eugenol and Hexyl cinnamic aldehyde) and 3 kinds of cosmetics were selected.The dorsal sides of both ears of female BALB/c mice were treated with 25μL/ear of the test solutions on 3 consecutive days, and the thickness of each ear was measured.BrdU solution was injected inter-peritoneally on day 5.On day 6, each auricle was weighed, the bilateral draining auricular lymph nodes were excised and weighed, then made into single cell suspension.BrdU was measured by ELISA using a commercial kit.Results Ear swelling and auricle weight of DNCB ( 1.0%) , Eugenol ( 25% and 50%) and number 3 cream foundation increased significantly ( P <0.05 or P <0.01), which may be considered as irritants.The others were negative.For LLNA, three chemicals and number 3 cream foundation pretended positive.Conclusion The combined LLNA/ear swelling/ear weight assay appears to be a reliable predictor of sensitization and irritancy potential, and is expected to play an important role in safety evaluation of cosmetics.