Whitening effect of panaxynol isolated from the leaves of Panax ginseng sprout

Panaxynol was isolated from the leaves of Panax ginseng sprout. The chemical structure was determined based on spectroscopic methods, including 1D NMR (¹H,¹³C, DEPT), 2D NMR (gCOSY, gHMBC, HSQC), Optical rotation, and IR spectroscopy. Panaxynol inhibited potent melanogenesis (28.3%) in Melan-a cells at 80 μM without cytotoxicity. In addition, panaxynol decreased tyrosinase and microphthalmia-associated transcription factor protein production in dose-and time-dependent manner. Panaxynol induced Akt and ERK phosphorylation level in Melan-a cell. Also, the specific inhibition of the Akt and ERK signaling pathways were studied by LY294002 and U0126 inhibitor, respectively, increased melanin synthesis. Moreover, the numbers of melanin pigment spot in the zebrafish yolk treated with panaxynol was reduced at the 80 μM. These results suggest that panaxynol purified from Panax ginseng sprout may be an effective whitening agent that regulates the expression of melanogenic enzymes.