scholarly journals Comparative Study of Curcumin and Its Hydrogenated Metabolites, Tetrahydrocurcumin, Hexahydrocurcumin, and Octahydrocurcumin, on Melanogenesis in B16F10 and MNT-1 Cells

Cosmetics ◽  
2021 ◽  
Vol 8 (1) ◽  
pp. 4
Author(s):  
Shilpi Goenka ◽  
Sanford R. Simon
Keyword(s):  
Curcuma Longa ◽  
Parent Compound ◽  
Tyrosinase Activity ◽  
Melanin Synthesis ◽  
Molecular Signaling ◽  
Protein Levels ◽  
B16f10 Cells ◽  
Signaling Mechanisms ◽  
Human Melanocytes ◽  
Mouse Cells

Curcumin, a bioactive from Curcuma longa, has been shown to possess anti-melanogenic activity previously; however, the effects of its hydrogenated metabolites (HMs)—Tetrahydrocurcumin (THC), Hexahydrocurcumin (HHC), and Octahydrocurcumin (OHC)—on melanogenesis have not been sufficiently explored. We have studied and compared three HMs (THC, HHC, and OHC) with the parent compound, curcumin (PC), on melanin synthesis in B16F10 mouse and MNT-1 human melanoma cells. Our results demonstrated that all the HMs were nontoxic over the concentration range 5–40 µM, while PC was nontoxic at 5 µM but induced toxicity at 20 and 40 µM in B16F10 cells. All three HMs enhanced melanin synthesis, while PC (5 µM) inhibited it. THC (40 µM) significantly stimulated melanin synthesis to a greater degree than HHC and OHC in both B16F10 and MNT-1 cells; the order of melanogenesis stimulation was THC = OHC > HHC in B16F10 mouse cells, while it was THC > HHC > OHC in MNT-1 cells. HMs stimulated melanogenesis by pathways not involving tyrosinase, as neither the intracellular tyrosinase activity nor the protein levels of tyrosinase were affected. In addition, mushroom tyrosinase activity, using L-Dihydroxyphenylalanine (L-DOPA) as the substrate, showed no direct effects of HMs. In summary, our results demonstrate that the HMs enhanced melanogenesis, which establishes that the hydrogenation of the heptadiene moiety of curcumin leads to a loss of its anti-melanogenic activity and instead results in the stimulation of melanogenesis. This stimulation is not further enhanced upon hydrogenation of the β-diketone, which was noted in MNT-1 cells, although the correlation to the number of keto groups differed in B16F10 cells where HHC was the weakest stimulator of melanogenesis. Collectively, THC with both keto groups intact is the best stimulator. Moreover, our results also validate that the electrophilicity of curcumin is necessary for its anti-melanogenic activity, as the non-electrophilic HMs did not inhibit melanogenesis. Furthermore, our results suggest that THC might hold promise as a stimulator of melanogenesis for treatment of hypopigmentation disorders and anti-graying therapies. Future studies to probe the molecular signaling mechanisms and test whether the pro-melanogenic activity of HMs is retained in primary human melanocytes are warranted.

scholarly journals Inhibitory Effects of Cycloheterophyllin on Melanin Synthesis

Molecules ◽  
2021 ◽  
Vol 26 (9) ◽  
pp. 2526
Author(s):  
Joong-Hyun Shim
Keyword(s):  
Functional Materials ◽  
Tyrosinase Activity ◽  
Melanin Synthesis ◽  
Activity Assay ◽  
Inhibitory Effects ◽  
Melanin Production ◽  
Messenger Ribonucleic Acid ◽  
B16f10 Cells ◽  
Cell Line Cell ◽  
Tyrosinase Related Protein

This study was performed to clarify the inhibitory effects of cycloheterophyllin on melanin synthesis. In order to elucidate the inhibitory effects of cycloheterophyllin on the B16F10 cell line, cell viability, messenger ribonucleic acid (mRNA) expressions, tyrosinase activity assay, and melanin production assay were measured. The effects of cycloheterophyllin on tyrosinase-related protein 1 (TYRP1)/TYRP2/tyrosinase (TYR)/microphthalmia-associated transcription factor (MITF) mRNA expressions and melanin content were determined. Quantitative real-time RT-PCR showed that cycloheterophyllin decreased the mRNA expression level of TYRP1/TYRP2/TYR/MITF genes and melanin production contents than α-MSH-treated B16F10 cells. The tyrosinase activity assay revealed that cycloheterophyllin decreased the melanin production in the B16F10 cells. These data show that cycloheterophyllin increases the whitening effects in the B16F10 cells; thus, cycloheterophyllin is a potent ingredient for skin whitening. Thus, further research on the mechanism of action of cycloheterophyllin for the development of functional materials should be investigated.

scholarly journals Liquiritin and Liquiritigenin Induce Melanogenesis via Enhancement of p38 and PKA Signaling Pathways

Medicines ◽  
2019 ◽  
Vol 6 (2) ◽  
pp. 68 ◽  
Author(s):  
Takuhiro Uto ◽  
Tomoe Ohta ◽  
Akihisa Yamashita ◽  
Shunsuke Fujii ◽  
Yukihiro Shoyama
Keyword(s):  
Signaling Pathways ◽  
Mek Inhibitor ◽  
Tyrosinase Activity ◽  
Licorice Root ◽  
Melanin Synthesis ◽  
Creb Phosphorylation ◽  
Pi3k Inhibitor Ly294002 ◽  
P38 Inhibitor ◽  
Protein Levels ◽  
Mitf Expression

Background: Liquiritin (LQ) and its aglycone, liquiritigenin (LQG), are major flavonoids in licorice root (Glycyrrhiza spp.). Our preliminary screening identified LQ and LQG, which promote melanin synthesis in the melanoma cells. In this study, we investigated the molecular mechanism of melanin synthesis activated by LQ and LQG. Methods: Murine (B16-F1) and human (HMVII) melanoma cell lines were treated with LQ or LQG. After incubation, melanin contents, intracellular tyrosinase activity, and cell viability were evaluated. Protein levels were determined using Western blotting. Results: LQ and LQG activated melanin synthesis and intracellular tyrosinase activity. The induction of melanin and intracellular tyrosinase activity by LQG was higher than that by LQ. LQ and LQG induced the expression of tyrosinase, tyrosinase-related protein (TRP)-1, and TRP-2. LQ and LQG also enhanced microphthalmia-associated transcription factor (MITF) expression, and cyclic AMP-responsive element-binding protein (CREB) phosphorylation. The phosphorylation of p38 and extracellular signal-regulated kinase (ERK), but not Akt, was significantly increased by LQ or LQG. Furthermore, LQ- or LQG-mediated melanin synthesis was partially blocked by p38 inhibitor (SB203580) and protein kinase A (PKA) inhibitor (H-89); however, ERK kinase (MEK) inhibitor (U0126) and phosphatidylinositol-3-kinase (PI3K) inhibitor (LY294002) had no effect. Conclusions: The results suggest that LQ and LQG enhance melanin synthesis by upregulating the expression of melanogenic enzymes, which were activated by p38 and PKA signaling pathways, leading to MITF expression and CREB phosphorylation.

scholarly journals Nanoemulsified adlay bran oil reduces tyrosinase activity and melanin synthesis in B16F10 cells and zebrafish

2019 ◽  
Vol 7 (10) ◽  
pp. 3216-3223 ◽  
Author(s):  
Yuwen Ting ◽  
Yin‐Ting Hu ◽  
Jing‐Yu Hu ◽  
Wen‐Chang Chang ◽  
Qingrong Huang ◽  
...  
Keyword(s):  
Tyrosinase Activity ◽  
Melanin Synthesis ◽  
B16f10 Cells

Stimulation of tyrosinase in human melanocytes by pro-opiomelanocortin-derived peptides

1995 ◽  
Vol 146 (3) ◽  
pp. 439-447 ◽  
Author(s):  
S D McLeod ◽  
C Smith ◽  
R S Mason
Keyword(s):  
Extracellular Matrix ◽  
Corneal Endothelium ◽  
Adrenocorticotropic Hormone ◽  
Test System ◽  
Tyrosinase Activity ◽  
Melanin Synthesis ◽  
Melanocyte Stimulating Hormone ◽  
Kinase C ◽  
Human Melanocytes ◽  
Stimulation Of

Abstract Human melanocytes, maintained on bovine corneal endothelium-derived extracellular matrix for at least 4 days in the absence of phorbol 12-myristate 13-acetate (PMA) and cholera toxin (CT), displayed increased tyrosinase activity when exposed to several pro-opiomelanocortinderived (POMC) peptides. Melanocytes from 9 of 14 donors showed significantly increased tyrosinase activity after treatment with adrenocorticotropic hormone (ACTH; mean increase 320±107 (s.e.m.)% of control, P<0·005), while melanocytes from 8 of 13 donors increased tyrosinase in the presence of diacetyl-melanocyte stimulating hormone (di-MSH; mean increase 223±31 (s.e.m.)% of control, P<0·005). Maximal increases in tyrosinase were seen after treatment with 10−10 m ACTH and with 10−6 m di-MSH. In two cell cultures which showed tyrosinase stimulation, melanin synthesis was similarly increased in the presence of added POMC peptides. PMA but not CT increased tyrosinase activity in melanocytes cultured under these conditions. In the presence of staurosporine, an inhibitor of protein kinase C (PKC), the magnitude of the increase in tyrosinase due to PMA, ACTH and di-MSH was significantly reduced. These results indicate that tyrosinase activity in melanocytes from most human donors, under appropriate conditions, is susceptible to the stimulatory effects of POMC peptides, that ACTH is considerably more potent than di-MSH in this test system and that in human cells the PKC pathway may be important in modulating melanogenesis. Journal of Endocrinology (1995) 146, 439–447

scholarly journals Novel Chemically Modified Curcumin (CMC) Analogs Exhibit Anti-Melanogenic Activity in Primary Human Melanocytes

2021 ◽  
Vol 22 (11) ◽  
pp. 6043
Author(s):  
Shilpi Goenka ◽  
Sanford R. Simon
Keyword(s):  
Cell Model ◽  
Human Keratinocytes ◽  
Dermal Fibroblasts ◽  
Tyrosinase Activity ◽  
In Vivo Studies ◽  
Protein Levels ◽  
Chemically Modified ◽  
Curcumin Analogs ◽  
Human Melanocytes

Hyperpigmentation is a dermatological condition characterized by the overaccumulation and/or oversecretion of melanin pigment. The efficacy of curcumin as an anti-melanogenic therapeutic has been recognized, but the poor stability and solubility that have limited its use have inspired the synthesis of novel curcumin analogs. We have previously reported on comparisons of the anti-melanogenic activity of four novel chemically modified curcumin (CMC) analogs, CMC2.14, CMC2.5, CMC2.23 and CMC2.24, with that of parent curcumin (PC), using a B16F10 mouse melanoma cell model, and we have investigated mechanisms of inhibition. In the current study, we have extended our findings using normal human melanocytes from a darkly pigmented donor (HEMn-DP) and we have begun to study aspects of melanosome export to human keratinocytes. Our results showed that all the CMCs downregulated the protein levels of melanogenic paracrine mediators, endothelin-1 (ET-1) and adrenomedullin (ADM) in HaCaT cells and suppressed the phagocytosis of FluoSphere beads that are considered to be melanosome mimics. All the three CMCs were similarly potent (except CMC2.14, which was highly cytotoxic) in inhibiting melanin production; furthermore, they suppressed dendricity in HEMn-DP cells. CMC2.24 and CMC2.23 robustly suppressed cellular tyrosinase activity but did not alter tyrosinase protein levels, while CMC2.5 did not suppress tyrosinase activity but significantly downregulated tyrosinase protein levels, indicative of a distinctive mode of action for the two structurally related CMCs. Moreover, HEMn-DP cells treated with CMC2.24 or CMC2.23 partially recovered their suppressed tyrosinase activity after cessation of the treatment. All the three CMCs were nontoxic to human dermal fibroblasts while PC was highly cytotoxic. Our results provide a proof-of-principle for the novel use of the CMCs for skin depigmentation, since at low concentrations, ranging from 5 to 25 µM, the CMCs (CMC2.24, CMC2.23 and CMC2.5) were more potent anti-melanogenic agents than PC and tetrahydrocurcumin (THC), both of which were ineffective at melanogenesis at similar doses, as tested in HEMn-DP cells (with PC being highly toxic in dermal fibroblasts and keratinocytes). Further studies to evaluate the efficacy of CMCs in human skin tissue and in vivo studies are warranted.

scholarly journals Ginsenosides Rb1 and Rg1 Stimulate Melanogenesis in Human Epidermal Melanocytes via PKA/CREB/MITF Signaling

2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Mao Lin ◽  
Bao-Xiang Zhang ◽  
Ci Zhang ◽  
Nan Shen ◽  
Yun-Ying Zhang ◽  
...  
Keyword(s):  
Cell Viability ◽  
Skin Pigmentation ◽  
Camp Response Element Binding ◽  
Tyrosinase Activity ◽  
Dependent Manner ◽  
Melanin Content ◽  
Protein Levels ◽  
Human Melanocytes ◽  
Element Binding Protein ◽  
Phosphorylated Creb

Reduced or defective melanin skin pigmentation may cause many hypopigmentation disorders and increase the risk of damage to the skin triggered by UV irradiation. Ginsenosides Rb1 and Rg1 have many molecular targets including the cAMP-response element-binding protein (CREB), which is involved in melanogenesis. This study aimed to investigate the effects of ginsenosides Rb1 and Rg1 on melanogenesis in human melanocytes and their related mechanisms. The effects of Rb1 and Rg1 on cell viability, tyrosinase activity, cellular melanin content and protein levels of tyrosinase, microphthalmia-associated transcription factor (MITF), and activation of CREB in melanocytes were assessed. Results showed that Rb1 or Rg1 significantly increased cellular melanin content and tyrosinase activity in a dose-dependent manner. By contrast, the cell viability of melanocytes remained unchanged. After exposure to Rb1 or Rg1, the protein levels of tyrosinase, MITF, and phosphorylated CREB were significantly increased. Furthermore, pretreatment with the selective PKA inhibitor H-89 significantly blocked the Rb1- or Rg1-induced increase of melanin content. These findings indicated that Rb1 and Rg1 increased melanogenesis and tyrosinase activity in human melanocytes, which was associated with activation of PKA/CREB/MITF signaling. The effects and mechanisms of Rb1 or Rg1 on skin pigmentation deserve further study.

scholarly journals Inhibitory Effects of the Bioactive Thermorubin Isolated from the Fungus Thermoactinomyces Antibioticus on Melanogenesis

Cosmetics ◽  
2020 ◽  
Vol 7 (3) ◽  
pp. 61
Author(s):  
Shilpi Goenka ◽  
Sanford R. Simon
Keyword(s):  
Molecular Mechanisms ◽  
Selective Inhibition ◽  
Melanoma Cells ◽  
Melanin Synthesis ◽  
Free System ◽  
Mouse Melanoma ◽  
B16f10 Cells ◽  
Skin Hyperpigmentation ◽  
Human Melanocytes

Skin hyperpigmentation disorders arise due to aberrant regulation of melanin synthesis and export. Current treatments include natural compounds like kojic acid and hydroquinone, which suffer from limitations due to adverse reactions. Thermorubin (TR) is a secondary metabolite derived from the fungus Thermoactinomyces antibioticus and has previously demonstrated to possess anti-inflammatory properties by inhibition of matrix metalloproteinases (MMPs), as well as antimicrobial activity. In the current study, we explored whether TR might be a used as a candidate for the treatment of skin hyperpigmentation disorders by studying its effects on melanin synthesis and melanin export in B16F10 mouse melanoma cells and primary human melanocytes derived from darkly-pigmented (DP) skin. Non-toxic doses of TR were first identified in B16F10 mouse melanoma cells. These doses were subsequently tested for their effects on both extracellular and intracellular melanin levels under conditions of basal and hormone-stimulated melanogenesis. Our results demonstrated that TR at 25 µM inhibited total melanin levels with selective inhibition of extracellular melanin in B16F10 cells under both basal and hormone-stimulated conditions. The mechanisms of inhibition did not include tyrosinase inhibition, either in cellular lysates or cell-free system. However, TR potently inhibited activity of α-glucosidase enzyme in vitro and exhibited antioxidant activity. Furthermore, our results with primary human melanocytes from DP skin showed that TR at 10 µM significantly suppressed dendricity along with an increase in accumulation of intracellular melanin. These findings point to a mechanism of action of TR as an exclusive inhibitor of melanosome export. Taken together, our preliminary results demonstrate that TR might offer a novel ingredient as a skin depigmenting agent for inclusion in cosmetic formulations. Further studies delineating molecular mechanisms of hypopigmentation of TR and testing in human skin tissue-equivalents are warranted.

scholarly journals Inhibitory Effects of Pinostilbene Hydrate on Melanogenesis in B16F10 Melanoma Cells via ERK and p38 Signaling Pathways

2020 ◽  
Vol 21 (13) ◽  
pp. 4732
Author(s):  
You Chul Chung ◽  
Chang-Gu Hyun
Keyword(s):  
Signaling Pathways ◽  
Tyrosinase Activity ◽  
Related Protein ◽  
Melanin Content ◽  
Inhibitory Effects ◽  
Protein Levels ◽  
B16f10 Cells ◽  
Mitogen Activated Protein ◽  
Underlying Mechanisms ◽  
Tyrosinase Related Protein

Melanin protects our skin from harmful ultraviolet (UV) radiation. However, when produced in excess, it can cause hyperpigmentation disorders, such as melanoma, freckles, lentigo, and blotches. In this study, we investigated the effects of pinostilbene hydrate (PH) on melanogenesis. We also examined the underlying mechanisms of PH on melanin production in B16F10 cells. Our findings indicated that PH significantly inhibits melanin content and cellular tyrosinase activity in cells without causing cytotoxicity. In addition, Western blot analysis showed that PH downregulated the protein levels of microphthalmia-associated transcription factor (MITF), tyrosinase, and other melanogenic enzymes, such as tyrosinase-related protein-1 (TRP-1) and tyrosinase-related protein-2 (TRP-2). Although PH activated the phosphorylation of extracellular signal-regulated kinase (ERK), it inhibited p38 mitogen-activated protein kinases (p38). Furthermore, the inhibition of tyrosinase activity by PH was attenuated by treatment with PD98059 (a specific ERK inhibitor). Additionally, p-AKT was upregulated by PH treatment. Finally, the inhibitory effects of PH on melanin content and tyrosinase activity were confirmed in normal human melanocytes. These results suggest PH downregulates melanogenesis via the inhibition of MITF expression, followed by the MAPKase signaling pathways. Thus, PH may be used to treat or prevent hyperpigmentation disorders and in functional cosmetic agents for skin whitening.

scholarly journals Novel Chemically Modified Curcumin (CMC) Derivatives Inhibit Tyrosinase Activity and Melanin Synthesis in B16F10 Mouse Melanoma Cells

Biomolecules ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 674
Author(s):  
Shilpi Goenka ◽  
Francis Johnson ◽  
Sanford R. Simon
Keyword(s):  
Enzyme Activity ◽  
Parent Compound ◽  
Radical Scavenging ◽  
Melanoma Cells ◽  
Tyrosinase Activity ◽  
Partial Recovery ◽  
Tyrosinase Inhibitor ◽  
Pyrocatechol Violet ◽  
Mouse Melanoma ◽  
Chemically Modified

Skin hyperpigmentation disorders arise due to excessive production of the macromolecular pigment melanin catalyzed by the enzyme tyrosinase. Recently, the therapeutic use of curcumin for inhibiting tyrosinase activity and production of melanin have been recognized, but poor stability and solubility have limited its use, which has inspired synthesis of curcumin analogs. Here, we investigated four novel chemically modified curcumin (CMC) derivatives (CMC2.14, CMC2.5, CMC2.23 and CMC2.24) and compared them to the parent compound curcumin (PC) for inhibition of in vitro tyrosinase activity using two substrates for monophenolase and diphenolase activities of the enzyme and for diminution of cellular melanogenesis. Enzyme kinetics were analyzed using Lineweaver-Burk and Dixon plots and nonlinear curve-fitting to determine the mechanism for tyrosinase inhibition. Copper chelating activity, using pyrocatechol violet dye indicator assay, and antioxidant activity, using a DPPH radical scavenging assay, were also conducted. Next, the capacity of these derivatives to inhibit tyrosinase-catalyzed melanogenesis was studied in B16F10 mouse melanoma cells and the mechanisms of inhibition were elucidated. Inhibition mechanisms were studied by measuring intracellular tyrosinase activity, cell-free and intracellular α-glucosidase enzyme activity, and effects on MITF protein level and cAMP maturation factor. Our results showed that CMC2.24 showed the greatest efficacy as a tyrosinase inhibitor of all the CMCs and was better than PC as well as a popular tyrosinase inhibitor-kojic acid. Both CMC2.24 and CMC2.23 inhibited tyrosinase enzyme activity by a mixed mode of inhibition with a predominant competitive mode. In addition, CMC2.24 as well as CMC2.23 showed a comparable robust efficacy in inhibiting melanogenesis in cultured melanocytes. Furthermore, after removal of CMC2.24 or CMC2.23 from the medium, we could demonstrate a partial recovery of the suppressed intracellular tyrosinase activity in the melanocytes. Our results provide a proof-of-principle for the novel use of the CMCs that shows them to be far superior to the parent compound, curcumin, for skin depigmentation.

scholarly journals Molecular and Biochemical Basis of Minocycline-Induced Hyperpigmentation—The Study on Normal Human Melanocytes Exposed to UVA and UVB Radiation

2021 ◽  
Vol 22 (7) ◽  
pp. 3755
Author(s):  
Jakub Rok ◽  
Zuzanna Rzepka ◽  
Justyna Kowalska ◽  
Klaudia Banach ◽  
Artur Beberok ◽  
...  
Keyword(s):  
Uv Radiation ◽  
Therapeutic Potential ◽  
Melanin Synthesis ◽  
Uvb Radiation ◽  
Biochemical Basis ◽  
Skin Hyperpigmentation ◽  
Human Melanocytes ◽  
Anti Cancer ◽  
Normal Human

Minocycline is a drug which induces skin hyperpigmentation. Its frequency reaches up to 50% of treated patients. The adverse effect diminishes the great therapeutic potential of minocycline, including antibacterial, neuroprotective, anti-inflammatory and anti-cancer actions. It is supposed that an elevated melanin level and drug accumulation in melanin-containing cells are related to skin hyperpigmentation. This study aimed to evaluate molecular and biochemical mechanism of minocycline-induced hyperpigmentation in human normal melanocytes, as well as the contribution of UV radiation to this side effect. The experiments involved the evaluation of cyto- and phototoxic potential of the drug using cell imaging with light and confocal microscopes as well as biochemical and molecular analysis of melanogenesis. We showed that minocycline induced melanin synthesis in epidermal melanocytes. The action was intensified by UV irradiation, especially with the UVB spectrum. Minocycline stimulated the expression of microphthalmia-associated transcription factor (MITF) and tyrosinase (TYR) gene. Higher levels of melanin and increased activity of tyrosinase were also observed in treated cells. Moreover, minocycline triggered the supranuclear accumulation of tyrosinase, similar to UV radiation. The decreased level of premelanosome protein PMEL17 observed in all minocycline-treated cultures suggests disorder of the formation, maturation or distribution of melanosomes. The study revealed that minocycline itself was able to enhance melanin synthesis. The action was intensified by irradiation, especially with the UVB spectrum. Demonstrated results confirmed the potential role of melanin and UV radiation minocycline-induced skin hyperpigmentation.

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