A murine in vitro model of allergic contact dermatitis to sesquiterpene alpha-methylene-gamma-butyrolactones.

The use of a lymphocyte transformation test (LTT) to provide evidence of allergic contact dermatitis was investigated. The haptens studied were alantolactone and isoalantolactone, two moderate allergens from Inula helenium L., a decorative and medicinal plant. Only alantolactone showed a significant response in vivo and in vitro in mice sensitized epicutaneously, without using Freund's complete adjuvant. Isoalantolactone did not show any sensitizing capacity in the murine model studied. The comparison of in vitro lymphocyte proliferation and in vivo allergenic capacity showed a good correlation and clearly demonstrates that, of the two sesquiterpene lactones, alantolactone is the better sensitizer.