AN ALTERNATIVE METHOD FOR TESTING ORAL MUCOSAL IRRITATION CAUSED BY SURFACTANTS

MAYUMI KOTANI1, YUKIMITSU MASAMOTO1 and MASAMI WATANABE2
1Safety Analysis Center R&D/Mfg/Technical HQ, Sunstar Inc, 3-1 Asahi-Machi Takatsuki Oaska 569 Japan; 2Division of Radiation Biology, Department of Health Sciences, Faculty of Pharaceutical Sciences, Nagasaki University, 1-14 Bunkyo-cho Nagasaki 852, Japan

Regular article AATEX 2(4):203-214

Abstract
Surfactant induced oral mucosal irritation and desquamation were assessed by the two-dimensional in vitro test which included neutral red assay, indirect immunostaining for fibronectin and tubulin, western blot for tubulin, and scanning electron microscopic (SEM) evaluation on normal human embryo kerotinocyte monolayers. Mucosal desquamation was also assessed by the three-dimensional in vitro test which included light microscopic (LM) and SEM evaluations of a three-dimensional culture of normal human gingival keratinocytes and fibroblasts treated with surfactants. Neutral red assay, and SEM evaluation in the two-dimensional in vitro test gave an index of the oral mucosal irritation. And, indirect immunostaining in the two-dimensional in vitro test, and LM and SEM evaluations in the three-dimensional in vitro test provided an index of desquamation. Benzalkonium chloride treatment resulted in mainly inflammation, while both sodium lauryl sulfate and sodium lauroyl sarcosinate treatments caused mainly desquamation. Tween 20 and Sucrose fatty acid ester did not produce any effects.
It seems that the evaluation of intra- and extra-cellular matrix is simple in the in vitro alternative method for oral mucosal desquamation.


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