Salidroside, the major active component of Rhodiola rosea, a herb with
antioxidant,
free radical scavenging and
tyrosinase inhibitory effects, has been recently reported in protecting the kerationcytes from the UV radiation, suggesting the potential of this component in depigmentation.
Paeonol is isolated from
Moutan Cortex Radicis with anti-
inflammation/microbial activities, was reported to induce the down-regulation of
microphthalmia-associated transcription factor and subsequently
tyrosinase. To testify the potential of these compounds as
melanin formation inhibitors for
hyperpigmentation therapy, the influence of
salidroside and
paeonol on pigmentation was investigated. With
arbutin as a positive control,
salidroside and
paeonol were evaluated for their inhibitory effect on the cell viability,
tyrosinase activity and
melanin synthesis in B16F10
melanoma cells, as well as their effects in UVB-induced
hyperpigmentation in brown guinea pig skins. It was demonstrated that the significant inhibition of
salidroside (33.0%) and
paeonol (22.2-30.9%) on the
tyrosinase activity is slightly lower than that of
arbutin (18.4-44.7%). However,
salidroside exhibited the dose-dependent inhibition (30.6-42.0%) in
melanin synthesis at a low concentration of 100 μM,
paeonol and
arbutin expressed inhibition rates of 27.4-37.2% and 25.8-45.6% within 500-1000 μM. The in vivo topical application of these compounds was demonstrated to obviously decrease the
hyperpigmentation on UVB stimulated guinea pig skin. This study provided the original evidence for the
salidroside and
paeonol as therapeutic agents for
pigmentation disorder and skin lightening, with further clinical investigation of these compounds in the field of depigmentation was suggested.