protopanaxatriol and Melanoma

Ginsenosides are major active components of ginseng, and have diverse pharmacological properties in traditional medicine. Recent reports have shown that ginsenosides modify skin physiology and mitigate skin disorders such as photoageing and hyperpigmentation. We evaluated the antimelanogenic efficacy of protopanaxatriol, a major category of ginsenosides, as a depigmenting agent. Protopanaxatriol significantly reduced intracellular and extracellular melanin content in a concentration-dependent manner in B16 melanoma cells treated with α-melanocyte-stimulating hormone. In normal human epidermal melanocytes, protopanaxatriol clearly decreased melanin synthesis and dendrite elongation. In addition, protopanaxatriol dramatically suppressed the expression of genes encoding the melanogenic proteins tyrosinase, tyrosinase-related protein-1 and -2, and microphthalmia-associated transcription factor through dephosphorylation of cAMP response element-binding protein. These results suggest that protopanaxatriol could be an effective candidate anti-melanogenic agent.

Topics: Animals; Cell Line, Tumor; Cyclic AMP Response Element-Binding Protein; Dose-Response Relationship, Drug; Drug Screening Assays, Antitumor; Gene Expression Regulation, Neoplastic; Humans; Intramolecular Oxidoreductases; Melanins; Melanoma; Membrane Glycoproteins; Mice; Microphthalmia-Associated Transcription Factor; Oxidoreductases; Sapogenins; Signal Transduction