trans-Dihydromorin is an effective hypopigmenting agent in normal skin cells, hypopigmenting agents effective in melanoma system may not be effective on normal melanocytes, indicating that a non-tumor melanocyte system is more suitable for the screening of hypopigmenting agents.

But their inhibitory effects were different in two cell lines. In b16 cells, oxyresveratrol showed stronger depigmenting effect than trans- Dihydromorin, with greater suppression on tyrosinase activity. Both of them induced post-transcriptional degradations of microphthalmia-associated transcription factor (MITF), leading to significant decreases of tyrosinase related protein 1 (TRP-1) and tyrosinase related protein 2 (TRP-2) production. In melan-a cells, trans- Dihydromorin exhibited stronger inhibition on melanin synthesis. It also induced greater suppression on the levels of tyrosinase, TRP-1 and TRP-2 via MITF down-regulation at both transcription and translation level. Evaluations in artificial skin model also demonstrated the depigmenting effects of trans- Dihydromorin[1]