Antimelanogenesis Effects of Theasinensin A

Abstract

Theasinensin A (TSA) is a major group of catechin dimers mainly found in oolong tea and black tea. This compound is also manufactured with epigallocatechin gallate (EGCG) as a substrate and is refined after the enzyme reaction. In previous studies, TSA has been reported to be effective against inflammation. However, the effect of these substances on skin melanin formation remains unknown. In this study, we unraveled the role of TSA in melanogenesis using mouse melanoma B16F10 cells and normal human epidermal melanocytes (NHEMs) through reverse transcription polymerase chain reaction (RT-PCR), Western blotting analysis, luciferase reporter assay, and enzyme-linked immunosorbent assay analysis. TSA inhibited melanin formation and secretion in α-melanocyte stimulating hormone (α-MSH)-induced B16F10 cells and NHEMs. TSA down-regulated the mRNA expression of tyrosinase (Tyr), tyrosinase-related protein 1 (Tyrp1), and Tyrp2, which are all related to melanin formation in these cells. TSA was able to suppress the activities of certain proteins in the melanocortin 1 receptor (MC1R) signaling pathway associated with melanin synthesis in B16F10 cells: cyclic adenosine monophosphate (cAMP) response element-binding protein (CREB), protein kinase A (PKA), tyrosinase, and microphthalmia-associated transcription factor (MITF). We also confirmed α-MSH-mediated CREB activities through a luciferase reporter assay, and that the quantities of cAMP were reduced by TSA in the enzyme linked immunosorbent assay (ELISA) results. Based on these findings, TSA should be considered an effective inhibitor of hyperpigmentation.

In Vitro Anti-Photoaging and Skin Protective Effects of Licania macrocarpa Cuatrec Methanol Extract

“…B16F10 cells were treated with α-MSH (100 nM) for 48 h within or without Lm-ME or arbutin. To analyze melanin secretion, the medium was incubated for 48 h and detected at 475 nm [ 52 ]. To evaluate the melanin content, the cells were harvested in e-tubes and washed with cold PBS twice.…”

HPLC-MS/MS Quantification of Flavan-3-ols, Xanthines, and Epigallocatechin-3-Gallate Oxidation Products in Tea Samples and New Insights into Their Cytotoxicity

“…In human epidermal melanocytes (NHEM cells), Lim et al determined the cytotoxic effects at concentrations above 50 μM after 48 h of theasinensin A incubation. In contrast, no change in cell viability was observed in B16F10 skin melanoma cells in a concentration range up to 25 μM . The results suggest that different cell types and organs have to be considered for cytotoxicity evaluation.…”

“…In contrast, no change in cell viability was observed in B16F10 skin melanoma cells in a concentration range up to 25 μM. 37 The results suggest that different cell types and organs have to be considered for cytotoxicity evaluation. Moreover, HepG2 cells were chosen in this study to reproduce the human pathways with the liver as a metabolizer of ingested tea catechins and oxidation products.…”

Pueraria protein extract inhibits melanogenesis and promotes melanoma cell apoptosis through the regulation of MITF and mitochondrial‑related pathways

“…A previous study indicated that humans and mice share a number of common genetic features and mice and murine cultured cells are typically used instead of human equivalents in biological experiments ( 31 ). A number of reagents have been found to have similar effects on mouse melanoma B16 cells and human epidermal melanocytes ( 32 – 35 ). It was hypothesized that the effects of PLP on melanogenesis in mouse melanoma cells and human melanocytes are likely to be similar, but further research is necessary as animal models provide only an approximation of the situation in humans.…”