Attenuation of in vitro and in vivo melanin synthesis using a Chinese herbal medicine through the inhibition of tyrosinase activity

Abstract

Background: In traditional Chinese medicine, the skin reflects the health of body organs. A skin whitening agent, named seven whitening creams (also called Chi-Bai-San), has been used since ancient times in China. Chi-Bai-San reduces melanin and helps to reduce wrinkles.

Purpose: We aimed to determine the skin-whitening ability and safe dose of the seven compounds in Chi-Bai-San.

Study design: A common use for Chinese medicine is decocted in water. To mimic the function of Chi-Bai-San apply in clinical, we boiled all seven compound in water, respectively. These single recipe extractions and a mixture of these seven items were used in zebrafish embryo and B16F10 melanoma cell to identify the anti-melanogenesis function.

Methods: Chi-Bai-San comprises Bai-Lian (Ampelopsis japonica), Bai-Ji (Bletilla striata), Bai-Zhi (Angelica dahurica), Bai-Zhu (Atractylodes macrocephala), Bai-Shau (Paeonia lactiflora), Fu-Ling (Wolfiporia cocos), and Jen-Ju-Fen (Pearl powder). All components were extracted by heating in distilled water. The supernatant was collected after centrifugation. The extracted components were introduced into zebrafish embryos at different doses to determine the safe dose. B16F10 melanoma cells were treated with the final dose of each component and the component mixture. Melanin content and tyrosinase activity were assessed in zebrafish and B16F10 cells. Chi-Bai-San and its components were exposed to α MSH-induced B16F10 cells, and detected for mechanism of anti-melanogenesis pathway.

Results: Most compounds were not toxic at a low dose (0.1 mg/ml), except A. macrocephala, which resulted in a survival rate of only 30% at 72 hpf. The final dose of A. dahurica, P. lactiflora, W. cocos, and pearl was 1 mg/ml; that of A. japonica was 0.5 mg/ml; and that of A. macrocephala and B. striata was 0.1 mg/ml. Chi-Bai-San markedly decreased melanin content 37.47% in zebrafish embryos. Further, Chi-Bai-San abolished tyrosinase activity and MITF-mediated tyrosinase expression by down regulating the upstream transcription factors ZEB2, β-catenin, and CREB2 in α MSH-induced B16F10 cells. Additionally, Chi-Bai-San might reduce melanosome secretion from melanocytes.

Conclusion: Our findings indicate that safety and efficacy of heat-extracted Chi-Bai-San, which can reduce αMSH-induced melanin production by inhibiting the key role of melogenic-related transcription factor and promote the synergic effect of seven types of traditional Chinese herbal medicines.

Keywords: Chi-Bai-San; Chinese medicine; Skin whitening, Melanin; Tyrosinase.