Contact sensitivity of and cross-sensitivity between 2-(2′-hydroxy-5′-methylphenyl)benzotriazole (Tinuvin ® P) and 2-(2′-hydroxy-3′-tert-butyl-5′-methylphenyl)-5-chlorobenzotriazole (Tinuvin ® 326) evaluated by lymph node cell proliferation and ear swelling response in mice

Abstract

Contact sensitivity of and cross-sensitivity between 2-(2′-hydroxy-5′-methylphenyl)benzotriazole (Tinuvin ® P, TP) and 2-(2′-hydroxy-3′- tert-butyl-5′-methylphenyl)-5-chlorobenzotriazole (Tinuvin ® 326, T326) were investigated in BALB/c mice. Mice received an intradermal injection and subsequent topical application of the test chemical. Following final application, auricular lymph node cell (LNC) proliferation was measured. In another experiment, the appearance of contact sensitivity was assessed by increases in ear thickness following challenge of the test chemical. Application of TP to mice caused a significant increase in LNC proliferation. Challenge of these mice with TP resulted in an increase in ear thickness. However, TP-sensitized mice did not show an increase in ear thickness by challenge with T326. Under the same conditions, application of T326 failed to induce either LNC proliferation or ear swelling response. The induction of LNC proliferative response was closely related to the ear swelling response by challenge. Following intradermal injection of TP, topical application of T326 to mice did not induce LNC proliferation. A significant ear swelling response was not induced by first challenge with TP or T326 but induced by rechallenge with TP. Topical exposure of mice to TP following injection of T326 failed to induce LNC proliferation or any ear responses by challenge with T326 and TP. These data suggest that TP is a sensitizer, while T326 is not a sensitizer, and these chemicals do not cross-sensitize.