Baicalein inhibits melanogenesis through activation of the ERK signaling pathway

Abstract

Abstract. Baicalein is one of the major flavonoids in Scutellaria baicalensis. However, the effects of baicalein on melanogenesis are unknown. The objective of this study was to evaluate the depigmenting capacity of baicalein and to elucidate its mechanism of action. B16F10 mouse melanoma cells were used to examine the effect of baicalein on melanogenesis by measurement of melanin content and tyrosinase activity after treatment. To ascertain the baicalein activity, the effect on two protein kinases, ERK and Akt and downstream microphthalmia-associated transcription factor (MITF) were examined by Western blotting and RT-PCR. Baicalein significantly inhibited melanin synthesis in a concentration-dependent manner without cytotoxicity. Tyrosinase activity was also reduced. Baicalein decreased MITF and tyrosinase levels but did not decrease MITF mRNA. Western blotting showed that baicalein induced ERK activation. Using the specific ERK phosphorylation inhibitor, PD98059, we blocked the hypopigmentation effect, and also abrogated the baicalein-mediated activation of ERK. However, baicalein did not induce Akt activation. These results suggest that the ERK pathway is involved in the melanogenic signaling cascade, and that ERK activation by baicalein reduces melanin synthesis via MITF downregulation and is subsequent to the inhibition of tyrosinase synthesis.

A novel peptide purified from the fermented microalga Pavlova lutheri attenuates oxidative stress and melanogenesis in B16F10 melanoma cells

“…One of the extensively investigated transduction mechanisms involved in the melanogenesis process is the MAPKs pathway [42,46]. Previous studies have revealed that phosphorylation of p38 MAPK can induce through activate MITF expression, and also phosphorylation of JNK and ERK can reduce melanogenesis through MITF phosphorylation and its subsequent degradation on B16F10 cells [47][48][49][50][51]. We therefore examined the influence of the purified peptide treatment on the activation of JNK, ERK and p38 MAPK attempting to further understand the molecular mechanisms involved in the pigmentation property of the purified peptide by western blot assay.…”

[6]-Shogaol inhibits melanogenesis in B16 mouse melanoma cells through activation of the ERK pathway

“…So far, many natural and synthetic agents have been found to inhibit melanogenesis in B16F10 cells through activation of the ERK and/or the Akt pathways. For example, baicalein, cimicifuga heracleifolia, and KHG22394 (a synthesized chemical) were found to decrease melanin synthesis by activating ERK or Akt [18,26,27] . Therefore, we are interested in the effects of [6]-shogaol on ERK and Akt activities.…”

“…In particular, the MAPK kinase (MEK)/extracellular signal-regulated kinase (ERK) and the PI3K/Akt pathways have been shown to negatively regulate melanin synthesis in melanocytes and melanoma cells [14][15][16][17][18] . Currently, cosmetic products possessing whitening effects occupy a large proportion of the cosmetic market and have become more popular than ever in Asia.…”

The Fascinating Effects of Baicalein on Cancer: A Review

“…A recent study also reported that baicalein inhibited melanogensis in B16F10 mouse melanoma cells by activating the ERK signaling pathway. Furthermore, in vitro studies revealed that the reduction of tyrosinase activity, downregulation of microphthalmia-associated transcription factor (MITF) protein expression, and activation of ERK have been involved in the mechanisms of baicalein-mediated inhibition of melanogensis [55]. Another study showed that baicalein inhibited the proliferation of B16F10 melanoma cells through catalyzing the formation of reactive oxygen species (ROS) by 12-lipoxygenase [56].…”