Topical drug effects on normal and proliferating epidermal cell models.

The effects of 28 different antiproliferative agents applied topically to normal and hyperproliferative hairless mouse skin were studied. Epidermal cell hyperproliferation was induced by an essential fatty acid-deficient diet or by irradiation with short-wavelength ultraviolet (UV) energy. Epidermal DNA synthesis was measured by hydroxyapatite column chromatography. We compared the effects of these drugs used on normal and hyperproliferative hairless mouse skin with clinical responses in patients with psoriasis treated using the same topical preparations. For most of the drugs tested, the normal and essential fatty acid-deficient mouse model effects showed a good correlation with clinical responses seen in treated patients with psoriasis. The short-wavelength UV energy-treated mouse model effects showed a poorer clinical correlation, perhaps partially caused by wide variations in DNA synthetic rates encountered in the epidermis in this model.