OBJECTIVE: To probe into the mechanism of schisandrin A antagonizes melanogenesis in melanocytes through mitogen-activated protein kinase（MAPK）/extracellular signal-regulated kinase（ERK） pathway. METHODS: The human epidermal melanocyte group

schizandrin A low

medium and high dose group（125

250

500 μmol/mL） were set up. After incubation

cell viability was measured by MTT method

apoptosis indicators were evaluated by flow cytometry

and melanin preparation standard curve was used to measure melanin synthesis ability

enzyme linked immunosorbent assay was used to measure the level of tyrosinase

the mRNA and protein expression levels of MAPK and ERK were determined by reverse transcription-polymerase chain reaction and Western blotting. RESULTS: Compared with the human epidermal melanocyte group

the OD value

survival rate

melanin synthesis level and tyrosinase level of schizandrin A low

medium and high dose group decreased

with statistically significant differences（P<0.05）. With the increasing dose of schizandrin A

the OD value

survival rate

melanin synthesis level and tyrosinase level of human epidermal melanocytes decreased

and the effect of each dose group of schisandrin A showed the dose-effect trend（P<0.05）. Compared with the human epidermal melanocyte group

the apoptotic rate

the mRNA and protein expression levels of MAPK

ERK in the schisandrin A low

medium and high dose group increased

with statistically significant differences（P<0.05）. With the increasing dose of schizandrin A

the apoptosis rate

the mRNA and protein expression levels of MAPK

ERK of human epidermal melanocytes increased

and the effects of each dose group of schisandrin A showed the dose-effect trend（P<0.05）. CONCLUSIONS: Schizandrin A can inhibit the proliferation of melanocytes

promote the apoptosis of melanocytes

and then inhibit the melanogenesis. Its mechanism may be related to the activation of MAPK/ERK pathway by promoting the mRNA and protein expression levels of MAPK and ERK in human epidermal melanocytes by schizandrin A.