The Biological Effect Of Salidroside On Melanocytes And The Discussion About The Selection Processes Of Whitening Chinese Herbal

Hyperpigmentation is a kind of pathological variant caused by various internal and external factors and characterized by brown patches, including such diseases as chloasma, freckle, and melanosis. Due to varied limitations, the safe and successful treatments are in wanted.It's showed that Rhodiolae Rosea L can be used as a depigmenting agent according to the clinical trial. So, we made a study of the pharmacological mechanism of this effect on the basis of molecular biological principle.Firstly, Melanocytes and melanoma B16 cells were employed in this study, the interference of Salidroside in the metabolism of melanocytes was evaluated, including the effects the proliferation of cells, tyrosinase activity and melanin content. It proved that Salidroside had fewer effects on proliferation of cells, and at the same time it can inhibit the activity of tyrosinase and melanin biogenesis of melanocytes. While,the extracts of Rhodiolae Rosea L showed no obviously inhibition activity in tyrosinase The results indicated that the tyrosinase activity inhibition was not related to the competitive inhibition on tyrosinase. So, how Salidroside inhibited the melanin biogenesis of melanocyte should be further studied . In the second part, the suppression of tyrosinase synthesis and gene expression by Salidroside were investigated with Western blot and RT-PCR. The result indicated that a certain level of concentration of Salidroside can suppress tyrosinase synthesis and gene expression., which maybe serve as the fundamental mechanism of the depigmenting effect of Salidroside. In the third part, we initiated a cellar model of hyperpigmentation irradiated by UVB and checked the interference of Salidroside on it. The study proved that Salidroside can obviously inhibit the melanin biogenesis of melanocytes promoted by UVB.Further, to evaluate the inhibitory activity of Rhodiolae Rosea L in vivo, its effect on melanin production in UVB-induced brown guinea pigs was examined,resorted to the efficiency evaluation, determination of melanin and the observation of tissue pathology. where a decrease of melanin production in the guinea pig model was observed. Also, Rhodiolae Rosea L extracts showed no side effect. It is proved that Rhodiolae Rosea L can inhibit the melanin biogenesis, the direct reason is the reduction of the transcription and protein expression of tyrosinase in melanocytes by Salidroside, while, it suggested that Rhodiolae Rosea L extraction can tyrosinase inhibition activity by competitive method, competitively inhibit the tyrosinase activity directly. So we suggest that the non- cellular mushroom tyrosinase inhibition experiment may be adopted as a kind of initial trail for the selection of new depigmenting compounds. while, the efficiency evaluation of depigmenting agent should be tested with tyrosinase activity inhibition experiment of melanocytes.