Melanogenesis In B16F10 Melanoma Cells Research Articles

Ethanolic Extract of Hippocampus abdominalis Exerts Anti-Melanogenic Effects in B16F10 Melanoma Cells and Zebrafish Larvae by Activating the ERK Signaling Pathway

The big belly seahorse (Hippocampus abdominalis), a well-known ingredient of traditional medicine, possesses anti-inflammatory, anti-aging, anti-fatigue, and anti-thrombotic properties, and also increases male fertility. This study demonstrates that the ethanolic extract of dried H. abdominalis (EEHA) has anti-melanogenic effects in B16F10 melanoma cells and zebrafish larvae. EEHA significantly reduced the α-melanocyte-stimulating hormone (α-MSH)-induced melanogenesis in B16F10 melanoma cells without causing cytotoxicity. At a concentration of 200 µg/mL, EEHA had significant anti-melanogenic activity in zebrafish larvae, accompanied by a severe reduction in the heart rate (118 ± 17 heartbeats/min) compared to that of the untreated group (185 ± 8 heartbeats/min), indicating that EEHA induces cardiotoxicity at high concentrations. Below 100 µg/mL, EEHA significantly reduced melanogenesis in zebrafish larvae in the presence or absence of α-MSH, while the heart rate remained unaltered. Additionally, EEHA downregulated the release of cyclic adenosine monophosphate (cAMP) and the phosphorylation of cAMP response element-binding protein (CREB) in B16F10 melanoma cells, which inhibited microphthalmia-associated transcription factor (MITF), leading to the inhibition of tyrosinase activity. EEHA also increased the phosphorylation of extracellular-signal regulated kinase (ERK). The ERK inhibitor PD98059 interfered with the anti-melanogenic activity of EEHA in B16F10 melanoma cells and zebrafish larvae, indicating that the ERK signaling pathway might regulate the anti-melanogenic properties of EEHA. Altogether, we conclude that EEHA represses the cAMP–CREB–MITF axis, which consequently inhibits tyrosinase-mediated melanogenesis. We propose that at low concentrations, EEHA can serve as a promising anti-melanogenic agent that could be used to prepare whitening cosmetics and for treating melanogenic disorders.

Antioxidant and Antimelanogenic Activities of Compounds Isolated from the Aerial Parts of Achillea alpina L.

Achillea alpina is widely distributed in Korea and is often used as a folk medicine for stomach disorders. Although a previous study isolated antioxidant compounds (flavonoid O-glucoside, sesquiterpene) from this plant, no systematic study of its chemical constituents had been reported. The present study aimed to identify the phytochemicals present in a methanol extract of A. alpina, assess their potential antioxidant activities in vitro, and determine their effects on melanogenesis in B16F10 melanoma cells. Column chromatographic separation of aqueous fractions of A. alpina led to the isolation of 17 compounds. The chemical structures of these compounds were determined using spectroscopic data from electrospray ionization-mass spectrometry and nuclear magnetic resonance. To the best of our knowledge, the present study is the first to identify compounds 2-10 and 12-17 in A. alpina. Furthermore, compound 6 possessed powerful antioxidant activity, while compound 15 suppressed intracellular tyrosinase activity and thus reduced melanogenesis in B16F10 cells. Therefore, our research suggested that these naturally occurring compounds have the potential to reduce oxidative stress and promote skin whitening. Further investigations will be required to elucidate the mechanisms underlying the antioxidant and antityrosinase activities of these compounds.

A mixture of seaweed extracts and glycosaminoglycans from sea squirts inhibits \u03b1-MSH-induced melanogenesis in B16F10 melanoma cells

BackgroundIn the present study, the skin-whitening effects of a marine-sourced mixture that includes a fucoidan-rich extract of Undaria pinnatifida (UPEF), a phlorotannin-rich extract of Ecklonia cava (ECE), and glycosaminoglycans (GAGs) from sea squirt skin were investigated.MethodsThe whitening effects of the mixture and its components were evaluated by measuring the inhibition of mushroom tyrosinase and melanin synthesis in alpha-melanocyte-stimulating hormone (α-MSH)-stimulated B16F10 melanoma cells.ResultsEach component alone markedly inhibited mushroom tyrosinase in a dose-dependent manner, and in α-MSH-stimulated B16F10 cells, they inhibited melanin synthesis and were cytotoxic. However, the whitening effects of UPEF, ECE, and GAGs in combination were greater than those of each component alone. A mixture in the ratio of 4:5:1 (UEG-451) showed the strongest activity without cytotoxicity. Further study suggested that UEG-451 inhibits α-MSH-stimulated melanogenesis in B16F10 cells by downregulating tyrosinase and tyrosinase-related proteins, such as TRP-1 and TRP-2, via the inhibition of MITF expression.ConclusionsThese results suggest that mixing the different components at optimum ratios might be an effective way to improve their bioactivities and reduce toxicity and that UEG-451 possesses strong whitening effects that could be used in the cosmetic industry.

Unripe Fruit Extracts of <i>Mangifera indica L.</i> Protect against AGEs Formation, Melanogenesis and UVA-Induced Cell Damage

In this study, we explored the effects of unripe fruit extracts of Mangifera indica L. on the anti-aging activity in skin cells. Mangifera indica L. is a popular economical and medicinal plant with numerous health-beneficial properties. The aqueous extracts of unripe fruit of Mangifera indica L. were obtained and subjected to HPLC and NMR analyses for the identification of bioactive compounds. The anti-glycation effect of Mango unripe fruit extracts was monitored by in vitro model system of AGEs (Advanced glycation end products) formation. Mango unripe fruit extracts significantly inhibited the AGEs formation in a dose-dependent manner. Meanwhile, Mango unripe fruit extracts possessed a comparable efficiency to commercialized Kojic acids in the inhibition of melanogenesis in B16-F10 melanoma cells. The UVA-induced cell damages can be prevented and repaired by Mango unripe fruit extracts in skin fibroblast CCD-966SK. Compared to the untreated control, Mango unripe fruit extracts significantly increased the cell viability while being applied before (36%) or after (43%) UVA irradiation. These results verified the potential application of Mango unripe fruit extracts in the skin protection and recovery from UVA irradiation, as well as the suppression of AGEs formation and melanogenesis.

Pyruvic acid/ethyl pyruvate inhibits melanogenesis in B16F10 melanoma cells through PI3K/AKT, GSK3β, and ROS‐ERK signaling pathways

Melanin is the main product of human melanocytes and functions to protect skin from ultraviolet (UV) radiation while conferring color to skin and hair. Tyrosinase is the rate-limiting enzyme for melanin synthesis along with tyrosinase-related protein (TRP)-1 and TRP-2. Microphthalmia-associated transcription factor regulates tyrosinase gene expression and is in turn regulated by extracellular signal-regulated kinase (ERK), phosphoinositide 3-kinase (PI3K)/AKT, and glycogen synthase kinase (GSK)3β signaling pathways. Pyruvic acid (PA) is an energy source for ATP synthesis in the tricarboxylic acid cycle that also acts as a reactive oxygen species (ROS) scavenger. As UV irradiation induces melanin synthesis and ROS generation, we speculated that PA or ethyl pyruvate (EP), a stable form of pyruvate, regulates melanogenesis. B16F10 melanoma cells served as a melanin synthesis model. Treatment with PA or EP suppressed melanin synthesis while increasing intracellular ROS levels, which was accompanied by increased ERK phosphorylation in the case of EP treatment. PA and EP induced GSK3β phosphorylation and activated PI3K/AKT signaling, leading to decreased melanin synthesis. These results indicate that PA and EP inhibit melanogenesis via PI3K/AKT and GSK3β signaling and targeting the ERK and GSK3β pathways, respectively. Thus, PA and EP can potentially be used for treatment of hyperpigmentation disorders.

Leukodin isolated from Artemisia capillaris inhibits alpha-melanocyte stimulating hormone induced melanogenesis in B16F10 melanoma cells

IntroductionThe demand for treatment of hyperpigmentation disorders are on the rise. Artemisia capillaris is a traditional herbal plant widely used in skin protective remedies. In the present study, the inhibitory effect of Artemisia capillaris ethanol extract on the production of melanin is examined, and the active compound was isolated from the crude extract and identified. MethodsThe structure of the purified active compound of A. capillaris ethanol extract (ACE) was elucidated by NMR spectroscopy. ACE at the concentration of 6.25, 12.5, 25, and 50 μg/ml and active compound at the concentration of 37.5, 75, and 150 μg/ml were treated alpha-melanocyte stimulating hormone (α-MSH) induced in B16F10 melanoma cells. Melanin contents, tyrosinase activity, and protein expression of melanogenesis-related proteins were analyzed in ACE or active compound treated or untreated control. ResultsACE significantly inhibited melanogenesis induced by α-MSH and tyrosinase activity without cell cytotoxicity in a dose-dependent manner. Western blot demonstrated that ACE downregulated the expression of melanocyte-specific proteins such as tyrosinase, tyrosinase-related protein-1 (TRP-1), and tyrosinase-related protein-2, which catalyzes the rate-limiting oxidation of tyrosine to melanin. The active compound was finally identified as leukodin. It inhibited melanin pigment synthesis and tyrosinase activity in B16F10 melanoma cells without cytotoxicity. In addition, the leukodin decreased TRPs expression in a dose-dependent manner. ConclusionsBioactivity-guided fraction identified leukodin is the active compound in ACE extract. Leukodin suppressed melanin synthesis through inhibition of the expression of melanogenic enzymes.

Anti-melanogenic effects of oyster hydrolysate in UVB-irradiated C57BL/6J mice and B16F10 melanoma cells via downregulation of cAMP signaling pathway

Ethnopharmacological relevancePacific oyster (Crassostrea gigas) has been used to treat pigmentary disorders such as freckles, melasma, and moles in Korea. Aim of the studyWe aimed to investigate the inhibitory effects of oyster hydrolysate (OH) on melanogenesis in B16F10 melanoma cells and UVB-irradiated C57BL/6J mice. Material and methodsThe molecular weight distribution and peptide sequences of OH were detected using MALDI-TOF and UHPLC. To evaluate the anti-melanogenic effects of OH, cell viability, melanin content, tyrosinase activity, intracellular cyclic adenosine monophosphate (cAMP) and protein expressions levels were measured in B16F10 cells. In addition, OH was orally administered to UVB-irradiated mice for 9 weeks. After sacrificing the mice, the whitening effects of OH were evaluated based on histological observations and protein expression levels. ResultsIn B16F10 cells, OH decreased melanin content and tyrosinase activity in a dose-dependent manner. OH exhibited anti-melanogenic activities via downregulation of cAMP signaling pathway, which consequently decreased melanin synthesis.In UVB-irradiated mice groups, OH decreased the number of active melanocytes and melanin granules. The expression of tyrosinase-related proteins and microphthalmia-associated transcription factor (MITF) decreased in the OH-administered groups. ConclusionsThese results show that OH inhibits melanin synthesis in B16F10 cells via downregulation of cAMP signaling pathway and in UVB-irradiated mice, by decreasing the number of active melanocytes and melanin granules.

Correlation between the Potency of Flavonoids on Mushroom Tyrosinase Inhibitory Activity and Melanin Synthesis in Melanocytes.

Twenty-seven flavonoids isolated from Dalbergia parviflora with vast structural diversity were screened for inhibitory activity against mushroom and murine tyrosinases using l-DOPA as the substrate. Among the flavonoids tested, only four—khrinone (5), cajanin (9), (3RS)-3′-hydroxy-8-methoxy vestitol (21), and (6aR,11aR)-3,8-dihydroxy-9-methoxy pterocarpan (27)—reacted with mushroom tyrosinase, with IC50 values of 54.0, 67.9, 67.8, and 16.7 μM, respectively, and only compound 27 showed inhibitory activity against murine tyrosinase. With cell-based assays, only compounds 9 and 27 effectively inhibited melanogenesis in B16-F10 melanoma cells (by 34% and 59%, respectively), at a concentration of 15 μM, without being significantly toxic to the cells. However, the crude extract of D. parviflora and some of the flavonoid constituents appeared to increase melanin production in B16-F10 cells, suggesting that there are flavonoids with both inhibitory and stimulatory melanogenesis in the crude extract. Studies on the correlation between the enzyme-based and cell-based assays showed that only the flavonoids with IC50 values below 50 μM against mushroom tyrosinase could inhibit the mammalian tyrosinase, and thus, reduce melanogenesis in B16-F10. Flavonoids with the IC50 values greater than 50 μM, on the other hand, could not inhibit the mammalian tyrosinase, and had either no effect or enhancement of melanogenesis. In conclusion, the tyrosinase enzyme from mushroom is not as selective as the one from mammalian source for the enzyme-based melanogenesis inhibitory screening, and the mammalian cell-based assay appears to be a more reliable model for screening than the enzyme-based one.

Anti-inflammatory Effect of Pratol in LPS-stimulated RAW 264.7 Cells via NF-κB Signaling Pathways

The Trifolium pratense L. (red clover), which blossoms, leaves and stems can be used as medicines for treatment of burns, skin diseases, diabetes and other diseases. Recently study shown that pratol (7-hydroxy-4-methoxyflavone), an O-methylated flavone in T. pratense has been evaluated to induce melanogenesis in B16F10 melanoma cells. However, the anti-inflammatory effect of pratol has not been reported. In this study, we investigated the effects of pratol on anti-inflammation. We also studied the mechanism of action of pratol in LPS-stimulated RAW 264.7 cells. The cells were treated with various concentration of pratol (25, 50, or 100 μM) and 25 μM ammonium pyrrolidinedithiocarbamate (APDC) was used as control. The results in LPS-stimulated RAW 264.7 cells showed that pratol significantly reduced nitric oxide (NO) and prostaglandin E2 (PGE2) production without any cytotoxic. In addition, pratol strongly decreased the expression of inducible nitric oxide synthase (iNOS) and cyclooygenase (COX-2). Furthermore, pratol reduced proinflammatory cytokines such as tumour necrosis factor (TNF)-α, interleukin (IL)-1β and IL-6. We also found that pratol strongly inhibited activation of nuclear factor kappa B (NF-κB) by reducing the p65 phosphorylation and protecting inhibitory factor kappa B alpha (IκBα) degradation. The results suggest that, pratol may be used to treat or prevent inflammatory diseases such as dermatitis, arthritis, cardiovascular and cancer.

In vitro inhibitory effect of sulfated galactans isolated from red alga Gracilaria fisheri on melanogenesis in B16F10 melanoma cells

Hyperpigmentation of the skin results from excessive melanin formation in melanocytes, and overproduction of melanin frequently leads to melanoma. The aim of this study was to investigate the potential of sulfated galactans (SG) from Gracilaria fisheri to inhibit melanin formation or melanogenesis. Cellular and molecular mechanisms of inhibition were also investigated. SG was evaluated in vitro for its inhibitory effect on mushroom tyrosinase activity, cell-free tyrosinase activity, and cellular tyrosinase activity. B16F10 mouse melanoma cells were cultured with SG and their tyrosinase activity and melanin content was compared with kojic acid, a known tyrosinase inhibitor. Moreover, the levels of expression of melanogenesis-related genes and proteins were determined by quantitative RT-PCR and enzyme-linked immunosorbent assay (ELISA), respectively. The result showed that SG had no inhibitory effect on mushroom tyrosinase activity and cell-free tyrosinase activity. However, SG significantly suppressed cellular tyrosinase activity and melanin production in B16F10 melanoma cells without any apparent cytotoxicity. Quantitative RT-PCR and ELISA revealed that SG downregulated the expression of microphthalmia-associated transcription factor (MITF), tyrosinase-related protein-1 (TRP-1), tyrosinase-related protein-2 (TRP-2), and tyrosinase mRNA and proteins. Taken together, the data suggest that SG may act as an anti-melanogenic agent by inhibiting the expression of MITF and cellular tyrosinase activity. SG may show potential as an ingredient in skin-whitening cosmetics or as a topical agent for the treatment of hyperpigmentation disorders.

The effects of vitamin B6 compounds on cell proliferation and melanogenesis in B16F10 melanoma cells

B16F10 murine melanoma cells are frequently used for the study of cancer and melanogenesis. The cells are usually cultured in Dulbecco's Modified Eagle Medium, with the addition of 20 µM pyridoxal (PL) or pyridoxine (PN) for vitamin B6. The difference between these vitamin B6 compounds is thought not to affect cell proliferation, whereas their influence on other physiological effects is poorly understood. In the present study, the effects of PL and PN on cell proliferation and melanogenesis in B16F10 cells were compared. At 500 µM PL significantly suppressed cell growth but the growth inhibitory effect of PN was weak. Although neither of the vitamin B6 compounds affected cell growth at 20 µM, melanogenesis was suppressed by 20 µM PL compared with the effect of PN. In addition, the expression levels of tyrosinase, which is the rate-limiting enzyme, correlated with the melanin content. The results of the present study indicate that PL may be more useful for melanoma therapy and suppression of skin pigmentation than PN. The results also signify the importance of medium selection for cell culture.

Pratol, an O-Methylated Flavone, Induces Melanogenesis in B16F10 Melanoma Cells via p-p38 and p-JNK Upregulation.

Tyrosinase is the rate-limiting enzyme critical for melanin synthesis. It controls pigmentation in the skin. Activation of tyrosinase is currently the most common approach in the development of tanning and haircare products. Pratol is a 7-hydroxy-4-methoxyflavone found in Trifolium pratense. In this study, we investigated the effects of pratol on melanogenesis. We also studied the mechanism of action of pratol in B16F10 mouse melanoma cells. The cells were treated with various concentrations (6.25, 12.5, 25, and 50 μM) of pratol to observe its effects. The results showed that pratol significantly increased melanin content and tyrosinase activity in the cells without being cytotoxic. In addition, pratol strongly increased the expression of tyrosinase and tyrosinase-related protein-1 and 2 by enhancing the expression of microphthalmia-associated transcription factor. Furthermore, pratol stimulated melanogenesis via the phosphorylation of p38, c-Jun N-terminal kinases (JNK), and extracellular signal–regulated kinase (ERK). The findings from an assay searching for the inhibitor revealed that SB203580 (a specific p38 inhibitor) or SP600125 (a p-JNK inhibitor) attenuated pratol-induced cellular tyrosinase activity whereas PD98059 (an ERK inhibitor) did not. Additionally, pratol interfered with the phosphorylation of p-AKT. We also found that pratol-induced melanogenesis was reversed by H89, which is a specific protein kinase A inhibitor. The results suggest that, owing to its multi-functional properties, pratol may be a potential tanning agent or a therapeutic agent for hair depigmentation in the cosmetic industry.

SoyasaponinAg inhibits α‑MSH‑induced melanogenesis in B16F10 melanoma cells via the downregulation of TRP‑2.

Saponins, which are glycosylated, represent a diverse group of biologically functional products in plants. In the present study, we investigated the effects of soyasaponin Ag, a secondary metabolite extracted from soybean, on α-melanocyte-stimulating hormone (α-MSH)-induced melanin synthesis in B16F10 mouse melanoma cells and the underlying molecular mechanisms. To elucidate the mechanisms through which soyasaponin Ag inhibits melanin synthesis, we performed cellular tyrosinase activity assays and analyzed the expression of the melanogenesis-related genes, tyrosinase, tyrosinase-related protein (TRP)-1 and TRP-2. We demonstrated that soyasaponin Ag inhibited α-MSH-induced melanin synthesis in melanoma cells. Of note, soyasaponin Ag had no inhibitory effect on intracellular tyrosinase activity. However, soyasaponin Ag inhibited TRP-2 expression in a dose-dependent manner. Therefore, the depigmenting effect of soyasaponin Ag may be due to the inhibition of tyrosinase expression or the enhancement of tyrosinase degradation. Moreover, soyasaponin Ag did not exert any toxic on B16F10 mouse melanoma cells, suggesting that soyasaponin is a safe component for use in skin care cosmetic formulations that are used for skin whitening.

Modulation of the interface between polyester and spent coffee grounds in polysaccharide membranes: Preparation, cell proliferation, antioxidant activity and tyrosinase activity

The structural, antioxidant and cytocompatibility properties of membranes prepared from polyhydroxyalkanoate (PHA) and spent coffee ground (SCG) blends (PHA/SCG) were studied. Acrylic acid-grafted PHA (PHA-g-AA) was used to enhance the desirable characteristics of these membranes, which had better tensile properties than the corresponding PHA/SCG membranes. The water resistance of the PHA-g-AA/SCG membranes was greater than that of the PHA/SCG membranes, and a cytocompatibility evaluation with mouse normal tail fibroblasts (FBs) indicated that both materials were nontoxic. Cell cycle assays of FBs on PHA/SCG and PHA-g-AA/SCG membrane samples were not affected by the DNA content related to damage. Moreover, SCG enhanced the saccharide and polyphenol contents, and antioxidant properties, of the PHA-g-AA/SCG and PHA/SCG membranes. Therefore, we analysed the effects of these compounds' membranes on melanogenesis in B16-F10 melanoma cells. The results demonstrated that PHA/SCG and PHA-g-AA/SCG membranes reduced cellular tyrosinase activities in vitro.

The lactoferricin B-derived peptide, LfB17-34, induces melanogenesis in B16F10 cells

Lactoferricin B (LfcinB), a peptide of bovine lactoferrin (LfB), exhibits multiple biological functions, including antimicrobial, antiviral, antioxidant and immuno-modulatory activities. However, the role of LfcinB-related peptides in melanogenesis remains unclear. In this study, a set of five LfcinB-related peptides was examined. We found that LfB17-34, an 18-mer LfcinB-derived peptide, increased melanogenesis in B16F10 melanoma cells without significantly affecting cell viability. LfB17-34 increased in vitro tyrosinase activity and melanin content in a dose-dependent manner. The results of RT-qPCR and western blot analyses showed that LfB17-34 increased the mRNA and protein expression of tyrosinase and tyrosinase-related protein 1 (Trp1). Moreover, LfB17-34 inhibited the phosphorylation of MAPK/Erk, but not p38 and Akt, and constitutively active MEK was able to reverse the LfB17-34-enhanced pigmentation, melanin content, and tyrosinase activity, suggesting a role of Erk signaling in the process of LfB17-34-mediated pigmentation. Taken together, these results suggest that LfB17-34 induces melanogenesis in B16F10 cells primarily through increased tyrosinase expression and activity and that LfB17-34 could be further developed for the treatment of hypopigmentation disorders.

The Extracts of Astragalus membranaceus Inhibit Melanogenesis through the ERK Signaling Pathway.

Melanin is a normal production protecting skin from environment-causing damage. Plants produce some agents in response to their environment. These agents could be applied in cosmetic production. Some Chinese herbals have immunomodulatory activities and modulate the symptoms of several diseases. Melanogenesis represents a complex group of conditions that are thought to be mediated through a complex network of regulatory processes. Previously, some studies found that the extracts of Astragalus membranaceus (PG2) regulated immunity and supported hematopoiesis. Herein, we want to determine the molecular mechanisms by which PG2 inhibits melanogenesis in B16F10 melanoma cells. The cellular melanin contents and expression of melanogenesis-related protein, including microphthalmia associated transcription factor (MITF) and tyrosinase were significantly reduced after PG2 treatment. Moreover, PG2 increased phosphorylation of ERK, without affecting phosphorylation of p38. These results suggested that PG2 as a new target in reducing hyperpigmentation through the ERK signal pathway. PG2 has potential for cosmetic usage in the future.

Depigmentation of α-melanocyte-stimulating hormone-treated melanoma cells by β-mangostin is mediated by selective autophagy.

Melanogenesis is a key pathway for the regulation of skin pigmentation and the development of skin-lightening/skin-whitening drugs or cosmetics. In this study, we found that β-mangostin from seedcases of Garcinia mangostana inhibited α-melanocyte-stimulating hormone (α-MSH)-mediated melanogenesis in B16F10 melanoma cells and a three-dimensional human skin model. β-Mangostin significantly inhibited the protein level of tyrosinase induced by α-MSH in UPS (ubiquitin proteasome system)-independent and lysosome-dependent manner. The inhibition of autophagy by 3-methyladenine treatment or ATG5 knockdown effectively recovered premelanosome protein as well as tyrosinase degraded by the β-mangostin treatment. However, rapamycin, a representative non-selective autophagy inducer, triggered autophagy in α-MSH-stimulated cells, which was characterized by a considerable decrease in p62, but it was unable to inhibit melanogenesis. Melanosome-engulfing autophagosomes were observed using transmission electron microscopy. Furthermore, previously formed melanin could be degraded effectively in an autophagy-dependent manner in β-mangostin-treated cells. Taken together, our results suggest that β-mangostin inhibits the melanogenesis induced by α-MSH via an autophagy-dependent mechanism, and thus, the depigmentation effect of β-mangostin may depend on autophagy targeted at the melanosome rather than non-selective autophagy.

The activation of melanogenesis by p-CREB and MITF signaling with extremely low-frequency electromagnetic fields on B16F10 melanoma

Melanin in the skin determines the skin color, and decreased melanin causes many hypopigmentation disorders and increased damage to skin by ultraviolet B (UVB) light irradiation. Here, we stimulate melanogenesis in B16F10 melanoma cells by using specific frequencies of ELF-EMFs. In this study, we focus on the melanogenesis of EMF-ELFs and find that 60–75Hz ELF-EMFs upregulate melanin synthesis by stimulated expression of tyrosinase and TRP-1 through inhibition of phosphorylation ERK, activation of CREB, and MITF up-regulation in B16F10 melanoma cells. The results show that 60–75Hz ELF-EMFs significantly increase secreted melanin, cellular melanin content, and tyrosinase activity, and the cell mitochondria activity, cell viability, and cell membrane condition are unchanged. Furthermore, the protein expression level of MITF and p-CREB signaling pathway are significantly increased. Moreover, 60Hz ELF-EMFs reduce the phosphorylate of ERK in B16F10 melanoma cells. These findings indicate that stimulation of melanogenesis by using ELF-EMFs has therapeutic potential for treating hypopigmentation disorders such as vitiligo.

Antitumoral, antioxidant, and antimelanogenesis potencies of Hawthorn, a potential natural agent in the treatment of melanoma.

The lack of an efficient agent that does not have the disadvantage of low activity (kojic acid), high cytotoxicity, and mutagenicity (hydroquinone), poor skin penetration (arbutin), or low stability in formulation (glabridin) led us to continue our research on new antipigmentation/skin-lightening agents. Therefore, research of natural products that can modulate the metabolism of pigmentation is of great interest. Otherwise, malignant melanoma is one of the most aggressive forms of skin cancer, with high metastatic potential, and currently, there is no effective chemotherapy against invasive melanoma. Therefore, it is necessary to develop new drugs with potent activity and weak side effects against melanoma. The in-vitro anticancer effect of hawthorn was analyzed against B16F10 melanoma cells using a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. The effect of isolated compounds from hawthorn on melanogenesis in B16F10 melanoma cells was investigated by measuring the amounts of melanin and tyrosinase spectrophotometrically at 475 nm. Balb/c mice models inoculated with B16F10 mouse tumor cells were used to evaluate the in-vivo antitumoral potential of hawthorn by assessing its effect on the growth of transplanted tumors. The antioxidant potential of tested samples was evaluated in B16F10 and primary human keratinocyte cells using a cellular antioxidant activity assay. Hawthorn tested samples inhibited effectively the growth of melanoma cells in vitro. Furthermore, it appears that tested samples from hawthorn reduced melanogenesis by inhibiting the tyrosinase activity of B16F10 cells in a dose-dependent manner. In-vivo studies showed that hawthorn total oligomer flavonoids extract treatment at a dose of 150 mg/kg body weight for 21 days in implanted tumor mice resulted in significant inhibition of the tumor growth volume and weight. In addition, tested samples showed significant cellular antioxidant capacity against the reactive oxygen species in B16F10 and primary human keratinocyte cells. Our results indicate that hawthorn could be considered as a promising agent for the treatment of melanoma as it shows antitumor activity in vitro and in vivo. Moreover, hawthorn constituents are shown to be highly effective at inhibiting tyrosinase-mediated melanogenesis in vitro on melanoma cells by preventing oxidation in these cells and without affecting the viability of normal human keratinocyte cells. Then, hawthorn might also be used as a new candidate of natural skin depigmenting agents in skin care products.

Valencene from the Rhizomes of Cyperus rotundus Inhibits Skin Photoaging-Related Ion Channels and UV-Induced Melanogenesis in B16F10 Melanoma Cells.

Ultraviolet (UV) radiation deeply penetrates skin and causes inflammation and pigmentary changes and triggers immune responses. Furthermore, accumulating evidence suggests that calcium ion channels, such as TRPV1 and ORAI1, mediate diverse dermatological processes including melanogenesis, skin wrinkling, and inflammation. The rhizomes of Cyperus rotundus have been used to treat inflammatory diseases including dermatitis. However, their effects on UV-induced photoaging-related ion channels remain unknown. Therefore, this study was undertaken to evaluate the antagonistic effects of C. rotundus extract and their constituents on TRPV1 and ORAI1 channels. Electrophysiological analysis revealed that valencene (1) isolated from the hexane fraction potently inhibited capsaicin-induced TRPV1 and ORAI1 currents at 90 μM (69 ± 15% and 97 ± 2% at -60 and -120 mV, respectively). The inhibitory effect of 1 on cytoplasmic Ca(2+) concentrations in response to ORAI1 activation (85 ± 2% at 50 μM) was also confirmed. Furthermore, 1 concentration-dependently decreased the melanin content after UVB irradiation in murine B16F10 melanoma cells by 82.66 ± 2.14% at 15 μg/mL. These results suggest that C. rotundus rhizomes have potential therapeutic effects on UV-induced photoaging and indicate that the therapeutic and cosmetic applications of 1 are worth further investigation.