Modulation of Melanin Synthesis by Rengyolone Isolated from the Root of Eurya emarginata in Melan‐a Cells

Abstract

In the course of screening for the melanogenesis inhibitors, rengyolone was isolated from Eurya emarginata (Thumb) Makino. Its chemical structure was determined on the basis of spectroscopic analysis including mass spectroscopy and nuclear magnetic resonance analysis. Rengyolone inhibited potent melanogenesis in melan-a cells with an IC50 value of 65 μM without cytotoxicity. Also, rengyolone showed a melanin biosynthesis inhibition zone in a culture plate of Streptomyces bikiniensis, which is commonly used as an indicator organism. Moreover, rengyolone dramatically reduced protein expression of melanogenic enzyme, tyrosinase. Furthermore, rengyolone presented inhibition on the body pigmentation in zebrafish model system and decreased melanin contents and tyrosinase activity. These results suggest that rengyolone isolated from E. emarginata may be an effective skin-whitening agent that regulates the expression of melanogenic enzymes.

Brassica rapa hairy root extracts promote skin depigmentation by modulating melanin production and distribution

“…Intriguingly, the two fractions with different chemical composition, exerted complementary and nonoverlapping activities on different skin cells, as proved by cellular and molecular assays. In particular, the tyrosinase inhibiting properties of the root extracts or root‐isolated compounds have recently attracted attention . We found that BrWEt, containing phenylpropanoids and glucosidic derivatives, was able to significantly inhibit intracellular tyrosinase activity and melanin content in melanocytes.…”

“…Root‐secreted compounds, such as glucosinolates, terpenoids, organic acids and flavonoids, as well as cell‐wall‐linked glycoproteins, represent a reservoir of defensive compounds which the plants use to protect themselves against pathogenic attacks and/or to enhance the natural defense response mechanisms . One of the most used defense mechanisms, that the roots employ, is the inhibition of tyrosinase activity, because melanin is one of the most widely distributed pigments found in bacteria, fungi, and animals …”

Use of zebrafish (Danio rerio) in experimental models for biological assay with natural products

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