A Newly Authenticated Compound from Traditional Chinese Medicine Decoction Induces Melanogenesis in B16-F10 Cells by Increasing Tyrosinase Activity

Abstract

Vitiligo is a kind of skin dysfunction on melanogenesis. The highly prevalent, chronic, and distinctive complexion changes on patients have imposed enormous psychic and economic burden on both individuals and society. Traditional Chinese Medicine (TCM) is a kind of precious source on chronic disease treatment, including skin dysfunctional diseases. In our previous study, a new compound named apigenin-7-butylene glucoside has been authenticated and purified from a prescription of Chinese traditional medicine formula which has been used clinically in vitiligo treatment. The aim of this work is to evaluate the effects of this compound on melanogenesis using melanoma cell B16-F10 in vitro. The results showed that apigenin-7-butylene glucoside had almost no cytotoxicity on B16-F10 cells within a lower dose of 5.0 μg ml^-1 and enhanced the melanin level to about 41% and tyrosinase activity to 1.32-fold when compared with controls. The compound showed minor cytotoxicity to B16-F10 cells at the higher concentration of 10 μg ml^-1 and 50 μg ml^-1, the inhibition rate was 8.4% and 11.8%, and the melanin level and tyrosinase activity showed a decreased trend because of the lower cell number at the higher concentrations. The results indicated that apigenin-7-butylene glucoside was safe to B16-F10 cells within a lower concentration, <5.0 μg ml^-1. Incubated with 5.0 ug ml^-1of apigenin-7-butylene glucoside for 48 hours, the mRNA and protein levels of Tyr, Trp-1, and Trp-2 genes were all increased except Mitf in B16-F10 cells. The stimulation of apigenin-7-butylene glucoside on melanogenesis of B16-F10 cells through Tyr, Trp-1, and Trp-2 pathway highlighted the potential usage of the compound in vitiligo treatment.

Figure 1

The chemical structure of apigenin-7-butylene glucoside.

Figure 2

Cell availability test of B16-F10 after subjecting to different concentrations of apigenin-7-butylene glucoside (∗ implies differences at p<0.005; ∗∗ implies significant differences at p<0.001).

Figure 3

Tyrosinase activity evaluation of B16-F10 cells to different concentrations of apigenin-7-butylene glucoside (∗ implies differences at p<0.005; ∗∗ implies significant differences at p<0.001).

Figure 4

Melanin level analysis of B16-F10 cells to different concentrations of apigenin-7-butylene glucoside (∗ implies differences at p<0.005; ∗∗ implies significant differences at p<0.001).

Figure 5

mRNA level assay of Tyr, Trp-1, Trp-2 and Mitf gene in B16-F10 cells after apigenin-7-butylene glucoside treatment (∗ implies differences at p<0.005; ∗∗ implies significant differences at p<0.001).

Figure 6

Expression level analysis of TYR, TRP-1, TRP-2 and MITF in B16-F10 cells after apigenin-7-butylene glucoside treatment (∗ implies differences at p<0.005; ∗∗ implies significant differences at p<0.001).