One hundred sixteen C57 BL mice were painted with either 8-MOP, 5-MOP or TMP solution in concentrations of 0.02%, 0.1%, and 0.5% each and UVA irradiated. Skin biopsies were performed at 1, 3, 5 and 7 weeks after LJVA irradiation.

The results measuring the number, area, and perimeter of the melanocytes after topical PLJVA were higher in the TMP-painted group than in the 8-MOP or 5-MOP painted groups. In all groups, the weekly changes showed an increasing value through five weeks. In comparing the drug concentrations used, 0.1% of chemicals produced the same or higher values than 0.5%.

There have been few studies on the effects of 5-MOP in photochemotherapy. In tho study 5-MOP produced a pigment-producing effect similar to 8-MOP. Therefore, if topical PIJVA with 5-MOP is used in clinical practice, we could expect a significant therapeutic effect in vitiligo.