Antioxidant and Anti-Melanogenesis Effects of Colloidal Gold Camellia sinensis L. Extracts

Abstract

Green tea extract derived from the leaves of Camellia sinensis L. (CS), is a representative beverage with antioxidant, anti-cancer, and anti-viral properties. CS extract is also used in cosmetics. Colloidal gold is generally a sol or colloidal suspension of gold nanoparticles in water. Colloidal gold green tea (CGCS), cultivated as a fertilizer using this colloidal gold solution, contains gold minerals and possesses anti-inflammatory, analgesic, and anti-tumor properties. However, the skin bioactivity of CGCS has not yet been investigated. In this study, we investigated the effect of the CGCS extract on skin whitening. CGCS extract contained high levels of phenols and flavonoids and displayed 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity in a concentration-dependent manner. CGCS extract inhibited melanin synthesis and tyrosinase activity in B16F10 cells more effectively than the CS extract. Moreover, the CGCS extract decreased the expression levels of the melanogenesis-related proteins, tyrosinase, tyrosinase-related proteins (TRPs), and microphthalmia-associated transcription factor (MITF). In conclusion, our study showed that the CGCS extract inhibits the expression of tyrosinase, TRP-1, and TRP-2 via the downregulation of MITF, thereby inhibiting melanin synthesis. Therefore, CGCS can potentially be used as a skin-whitening ingredient in the cosmetic industry.

Inhibitory Effects of Polyphenol- and Flavonoid-Enriched Rice Seed Extract on Melanogenesis in Melan-a Cells via MAPK Signaling-Mediated MITF Downregulation

“…The polyphenol-enriched Rosa rugosa extract exerts similar effect as observed in the current study by reducing the mRNA and protein expression levels of MITF, tyrosinase, TRP-1, and TRP-2 in murine melanoma cells [48]. In addition, Shin, S. et al [49] demonstrated that the colloidal gold green tea extract, which contains high levels of phenols and flavonoids, increased antioxidative and anti-melanogenic activities via the downregulation of MITF, tyrosinase, TRP-1, and TRP-2. MITF is an important transcription factor in melanin synthesis that regulates the production of tyrosinase, TRP-1 and TRP-2 [3].…”

Chemical Composition and Skin-Whitening Activities of Siegesbeckia glabrescens Makino Flower Absolute in Melanocytes

“…MITF is a key transcription factor that induces the expressions of tyrosinase-related proteins (TRP-1 and TRP-2) and tyrosinase and promotes melanin synthesis [7]. Furthermore, it has been reported that the expressions of tyrosinase, TRP-1, and TRP-2 are inhibited through MITF downregulation and that this response was associated with reduced melanin production in B16F10 cells [34]. Phytochemicals (kirenol and methyl ent-16α,17-dihydroxykauran-19-oate), which were derived from SGM, inhibited melanogenesis by inhibiting MITF-mediated TRP-1, TRP-2, and tyrosinase activation in B16F10 cells [19].…”

Wybrane zagadnienia z zakresu produkcji surowców, żywności i kosmetyków, t. 3

“…Testowany ekstrakt hamował syntezę melaniny, a także aktywność enzymu tyrozynazy. Dodatkowo przedstawiono, że ekstrakt cechowała wyższa aktywność antyoksydacyjna porównaniu z kwasem L-askorbinowym [Shin i in. 2022].…”