Effects of 1α,25-Dihydroxy-Vitamin D3 and Calcipotriol on Organotypic Cultures of Outer Root Sheath Cells: A Potential Model to Evaluate Antipsoriatic Drugs

In the 1993 study, the effects of 1α,25-dihydroxy-vitamin D3 and calcipotriol on outer root sheath (ORS) cells were examined to assess their potential as antipsoriatic drugs. The study demonstrated that at a concentration of 10^-6 M, both compounds completely halted ORS cell proliferation in monolayer cultures, but had a reduced effect at 10^-8 M. In organotypic cultures, the compounds led to a thinner living cell layer and a thicker horny layer, with decreased expression of differentiation markers, without affecting cell proliferation. This suggests that the vitamin D analogues primarily promote differentiation rather than inhibit proliferation, which could be advantageous in treating psoriasis. However, the number of individuals from whom ORS cells were derived was not mentioned.