Medina, J., A. De Brugerolle De Fraissinette, C. Elsaesser, V. Picarles, O. Grenet, S. Chibout, M. Kolopp, U. Junker, M.E. Ebelin, P. Burtin, B. Vogel and A. Cordier. (2000). Predictive Value of a Human Skin Equivalent (Apligraf) for the Evaluation of Skin Irritation Potential. The Toxicologist 54(1). Abstract #687.

sodium lauryl sulfate - 00151-21-3; calcipotriol - 112965-21-6; trans-retinoic acid - 00302-79-4

The present study was designed to investigate the response of the human skin equivalent Apligraf in vitro to the application of irritant substances, and its predictivity as a screening tool for skin irritant potential in humans. Sodium lauryl sulfate, calcipotriol and trans-retinoic acid were applied to Apligraf in vitro for 24 hr. Cell viability (lactate dehydrogenase leakage, MTT mitochondrial reduction), release and mRNA expression of the pro-inflammatory cytokines IL-1-alpha and IL-8, and morphological changes were assessed. The same products were applied to 30 healthy volunteers in a double-blind, randomized, vehicle-controlled within-subject study. The skin reactions after repeated 24-h applications over 3 weeks under Finn chamber patches were monitored by visual scoring and biophysical methods (TEWL, chromametry and blood flow). The sensitivity, specificity and predictivity of the Apligraf for assessing skin irritation were evaluated. Sodium lauryl sulphate was cytotoxic to Apligraf, and increased the release and expression of cytokines at low (0.2%, 0.4%), but not at high (0.8%, 1%) concentrations. It induced severe irritancy in vivo. Trans-retinoic acid increased the expression and release of cytokines with no detectable cytotoxicity, and showed moderate irritancy in humans. Calcipotriol did not affect cell viability, but it increased the production of cytokines, and was mild to moderate for healthy volunteers. Apligraf, used for in vitro testing showed a good predictive value for the substances under investigation. In conclusion, the irritation potential of the tested products could be predicted with Apligraf, by monitoring cytotoxicity, the profile of proinflammatory cytokines and morphological changes.