Topical Application of a Protein Kinase C Inhibitor Reduces Skin and Hair Pigmentation

In a 2004 study, researchers found that bisindolylmaleimide (Bis), a protein kinase C (PKC) inhibitor, effectively reduced skin and hair pigmentation. Bis was shown to block tyrosinase activity, which is crucial for melanin production, in cultured human melanocytes. In vivo, Bis application led to less tanning in UV-irradiated guinea pigs and lighter regrowing hair in mice. The study involved four guinea pigs for the tanning experiments and an unspecified number of mice for the hair color experiments. These findings indicate that PKC inhibition could be a viable method for controlling pigmentation in the epidermis and hair, potentially serving as a therapeutic strategy for pigmentation disorders.