arbutin and Melanoma

Human tyrosinase (

Topics: Agaricales; Amino Acid Sequence; Biological Factors; Drug Delivery Systems; Drug Design; Enzyme Inhibitors; Humans; Melanins; Melanocytes; Melanoma; Monophenol Monooxygenase; Pigmentation; Protein Structure, Secondary; Skin Lightening Preparations

Topics: Agaricales; Amides; Antineoplastic Agents; Cell Proliferation; Cell Survival; Cinnamates; Dose-Response Relationship, Drug; Drug Screening Assays, Antitumor; Humans; Melanoma; Molecular Docking Simulation; Molecular Structure; Monophenol Monooxygenase; Structure-Activity Relationship; Tumor Cells, Cultured

In our previous study, the isolation of ugonin J, K, and L, which are luteolin derivatives, from the roots of Helminthostachys zeylanica and their identification as potent melanogenesis inhibitors, was described. The structure activity relationship (SAR) investigation in that study revealed that the catechol moiety in the B-ring of the flavone skeleton of ugonin K was important for its melanogenesis inhibitory activity, and the presence of the low polarity substituents at the C-7 position enhanced this activity. In order to further investigate the SAR of the C-7-substituent in the luteolin derivatives, different groups were selectively introduced at the C-7 position of luteolin after borax protection of the catechol hydroxyl group and the C-5 hydroxyl group. NMR and MS analysis of the borax protected derivatives revealed that the borax protects not only hydroxyl groups of catechol on the B ring but also the 5-hydroxyl group on the A ring. Eight luteolin derivatives were synthesized and evaluated for melanogenesis inhibitory effect in B16 melanoma cells. Two bulky groups and six alkoxyl groups were introduced at the C-7 position. The resulting luteolin derivatives showed improved melanogenesis and cell proliferation inhibitory activities. From among these derivatives, 7-O-hexylluteolin (7) showed the highest activity and inhibited the melanogenesis to 14% at 6.25 μM. The present study also revealed that the length of the carbon chain rather than the bulky substituent was more important for the melanogenesis inhibitory activity.

Topics: Antineoplastic Agents, Phytogenic; Apoptosis; Cell Line, Tumor; Cell Proliferation; Dose-Response Relationship, Drug; Drug Screening Assays, Antitumor; Ferns; Humans; Luteolin; Melanoma; Molecular Structure; Structure-Activity Relationship

Dimeric cynnamoyl analogues (DCAs) with depigmenting activity have been developed. In this study, a role of diamide linkage chain length of DCAs as a tyrosinase inhibitor was investigated on tyrosinase inhibitory activity, antioxidative activity, hydrophobicity and anti-melanogenesis as well as structural characteristics and dipole moments based on density functional theory. DCAs with different diamide-link chain lengths (n = 2, 3, and 4) and various functional groups (m-coumaroyl, p-coumaroyl, isoferuloyl and feruloyl groups) were synthesized. DCAs with a diamide-link chain length of three indicated high inhibitory effect of melanin production on α-melanocyte stimulating hormone (α-MSH) stimulated B16F1 cells. Approach of p-hydroxyl group of DCAs to active site of tyrosinase, an important melanogenic enzyme, is interfered by addition of m-methoxy group. In structural modeling based on density functional theory, DCAs with a diamide-link chain length of three showed folded shapes, and they had lower dipole moment than with a diamide-link chain length of two or four. Thus, for the enhancement of the depigmenting activities of dimeric compounds, the diamide-link chain length is important. Our results provide an important index for the design of dimeric compounds with physiological activities.

Topics: Agaricales; Amides; Animals; Antioxidants; Cell Survival; Cinnamates; Density Functional Theory; Dimerization; Dose-Response Relationship, Drug; Melanoma; Mice; Molecular Structure; Monophenol Monooxygenase; Structure-Activity Relationship; Tumor Cells, Cultured

Deoxyarbutin (DeoxyArbutin, dA), a natural compound widely used in skin lighting, displayed selectively cytotoxicity in vitro. In the study, we found that dA significantly inhibited viability/proliferation of B16F10 melanoma cells, induced tumour cell arrest and apoptosis. Furthermore, dA triggered its pro-apoptosis through damaging the mitochondrial function (membrane potential loss, ATP depletion and ROS overload generation etc.) and activating caspase-9, PARP, caspase-3 and the phosphorylation of p38. Treatment with p38 agonist confirmed the involvement of p38 pathway triggered by dA in B16F10 cells. The in vivo finding also revealed that administration of dA significantly decreased the tumour volume and tumour metastasis in B16F10 xenograft model by inhibiting tumour proliferation and inducing tumour apoptosis. Importantly, the results indicated that dA was specific against tumour cell lines and had no observed systemic toxicity in vivo. Taken together, our study demonstrated that dA could combate tumour in vitro and in vivo by inhibiting the proliferation and metastasis of tumour via a p38-mediated mitochondria associated apoptotic pathway.

Topics: Animals; Antineoplastic Agents; Apoptosis; Arbutin; Cell Line, Tumor; Cell Proliferation; MAP Kinase Signaling System; Melanoma; Melanoma, Experimental; Mice; Mitochondria; Models, Biological; Tumor Burden

In our searching for novel tyrosinase inhibitors from natural sources, (S)-N-trans-feruloyloctopamine isolated from garlic skin was found to be a potential mushroom tyrosinase inhibitor. Here, we examined the effects of the potential tyrosinase inhibitor in B16F10 cells on intracellular melanin contents, cytotoxicity, and the signaling mechanism involved in the expression of tyrosinase. The results showed the inhibitor displayed little or no cytotoxicity at all concentrations examined and decreased the relative melanin contents in a dose-dependent manner in the α-MSH-stimulated B16F10 cells. Real-time PCR and Western blot analysis showed that it inhibits melanogenesis signaling by down-regulates mRNA and protein expression levels of tyrosinase, which leads to a lower melanin contents. These results suggested that (S)-N-trans-feruloyloctopamine was an ideal tyrosinase inhibitor, and could be used in food and medical industry.

Topics: Agaricales; Animals; Cell Line, Tumor; Coumaric Acids; Dose-Response Relationship, Drug; Enzyme Inhibitors; Garlic; Gene Expression Regulation, Enzymologic; Melanins; Melanoma; Mice; Monophenol Monooxygenase; Octopamine; Structure-Activity Relationship

There are two established depigmenting agent assays currently in use. However, these methods are unreliable and time-consuming. Therefore, it will be valuable to establish a better assay system for depigmenting agent analysis. In this study, we established a melanogenesis regulation assay system using a fluorescent protein reporter combined with the promoters for the microphthalmia-associated transcription factor (MITF), tyrosinase (Tyr) and dopachrome tautomerase (Dct) genes in MeWo human melanoma cells. We used several melanogenesis regulators, including theophylline, hesperetin, arbutin and rottlerin, to confirm the function of this assay system. The established MeWo/pMITF-EGFP, MeWo/pTyr-EGFP and MeWo/pDct-EGFP stable cells integrated the pMITF-EGFP, pTyr-EGFP and pDct-EGFP plasmids into their genomic DNA. These stably transfected cells were used to examine alterations in the expression of the MITF, Tyr and Dct genes. All of the tested compounds, including theophylline, hesperetin, arbutin and rottlerin, could be analyzed in the stable cells, producing reliable results. Therefore, we believe that this melanogenesis regulation assay system can be used as a rapid and reliable assay system to analyze the regulation of melanogenesis by many known or unknown compounds.

Topics: Acetophenones; Arbutin; Benzopyrans; Cell Line, Tumor; Drug Evaluation, Preclinical; Enzyme Induction; Gene Expression Regulation, Neoplastic; Genes, Reporter; Genes, Synthetic; Green Fluorescent Proteins; Hesperidin; Humans; Intramolecular Oxidoreductases; Melanins; Melanoma; Melanoma, Experimental; Microphthalmia-Associated Transcription Factor; Microscopy, Fluorescence; Monophenol Monooxygenase; Neoplasm Proteins; Promoter Regions, Genetic; Recombinant Fusion Proteins; RNA, Messenger; Skin Lightening Preparations; Theophylline; Transfection

Although the toxicogenomics of A375 human malignant melanoma cells treated with arbutin have been elucidated using DNA microarray, the proteomics of the cellular response to this compound are still poorly understood. In this study, we performed proteomic analyses to investigate the anticancer effect of arbutin on the protein expression profile in A375 cells. After treatment with arbutin (8 microg/ml) for 24, 48 and 72 h, the proteomic profiles of control and arbutin-treated A375 cells were compared, and 26 differentially expressed proteins (7 upregulated and 19 downregulated proteins) were identified by MALDI-Q-TOF MS and MS/MS. Among these proteins, 13 isoforms of six identical proteins were observed. Bioinformatic tools were used to search for protein function and to predict protein interactions. The interaction network of 14 differentially expressed proteins was found to be correlated with the downstream regulation of p53 tumor suppressor and cell apoptosis. In addition, three upregulated proteins (14-3-3G, VDAC-1 and p53) and five downregulated proteins (ENPL, ENOA, IMDH2, PRDX1 and VIME) in arbutin-treated A375 cells were validated by RT-PCR analysis. These proteins were found to play important roles in the suppression of cancer development.

Topics: Antineoplastic Agents; Arbutin; Cell Line, Tumor; Down-Regulation; Humans; Melanoma; Metabolic Networks and Pathways; Protein Binding; Proteomics; Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; Tandem Mass Spectrometry; Up-Regulation

A series of N-hydroxy-N'-phenylthiourea and N-hydroxy-N'-phenylurea analogues were prepared and evaluated as inhibitors of tyrosinase and melanin formation. The most active analogue 1 inhibited mushroom tyrosinase with an IC(50) of around 0.29 microM and also retained a substantial potency in cell culture by reducing pigment synthesis by 78%. Therefore, compound 1 could be considered as a promising candidate for preclinical drug development for skin hyperpigmentation application.

Topics: Agaricales; Animals; Cell Line, Tumor; Dose-Response Relationship, Drug; Inhibitory Concentration 50; Melanins; Melanocytes; Melanoma; Mice; Molecular Structure; Monophenol Monooxygenase; Peptides; Phenylthiourea; Stereoisomerism; Structure-Activity Relationship; Toxicity Tests

To develop a new skin whitening agent, arbutin-beta-glycosides were synthesized and evaluated for their melanogenesis inhibitory activities. Three active compounds were synthesized via the transglycosylation reaction of Thermotoga neapolitana beta-glucosidase and purified by recycling preparative HPLC. As compared with arbutin (IC(50 )= 6 mM), the IC(50 )values of these compounds were 8, 10, and 5 mM for beta-D -glucopyranosyl-(1-->6)-arbutin, beta-D: -glucopyranosyl-(1-->4)-arbutin, and beta-D -glucopyranosyl-(1-->3)-arbutin, respectively. beta-D: -Glucosyl-(1-->3)-arbutin also exerted the most profound inhibitory effects on melanin synthesis in B16F10 melanoma cells. Melanin synthesis was inhibited to a significant degree at 5 mM, at which concentration the melanin content was reduced to below 70% of that observed in the untreated cells. Consequently, beta-D: -glucopyranosyl-(1-->3)-arbutin is a more effective depigmentation agent and is also less cytotoxic than the known melanogenesis inhibitor, arbutin.

Topics: Animals; Arbutin; beta-Glucosidase; Cell Line, Tumor; Cell Survival; Glycosides; Glycosylation; Melanins; Melanoma; Mice; Molecular Structure; Thermotoga neapolitana

Although arbutin is a natural product and widely used as an ingredient in skin care products, its effect on the gene expression level of human skin with malignant melanoma cells is rarely reported. We aim to investigate the genotoxic effect of arbutin on the differential gene expression profiling in A375 human malignant melanoma cells through its effect on tumorigenesis and related side-effect. The DNA microarray analysis provided the differential gene expression pattern of arbutin-treated A375 cells with the significant changes of 324 differentially expressed genes, containing 88 up-regulated genes and 236 down-regulated genes. The gene ontology of differentially expressed genes was classified as belonging to cellular component, molecular function and biological process. In addition, four down-regulated genes of AKT1, CLECSF7, FGFR3, and LRP6 served as candidate genes and correlated to suppress the biological processes in the cell cycle of cancer progression and in the downstream signaling pathways of malignancy of melanocytic tumorigenesis.

Topics: Arbutin; Cell Line, Tumor; Gene Expression Profiling; Gene Expression Regulation, Neoplastic; Humans; Melanoma; Oligonucleotide Array Sequence Analysis; Skin Neoplasms; Toxicogenetics

Alpha-arbutin is a tyrosinase inhibitor. We synthesized alpha-arbutin-alpha-glycosides by the transglycosylation reaction of cyclomaltodextrin glucanotransferase from Bacillus macerans using alpha-arbutin and starch as acceptor and donor molecules, respectively. We isolated and characterized two major products from the reaction mixture. The structural analyses using 13C- and 1H-NMR spectroscopy proved that they were 4-hydroxyphenyl alpha-maltoside (alpha-Ab-alpha-G1) and 4-hydroxyphenyl alpha-maltotrioside (alpha-Ab-alpha-G2). Both alpha-Ab-alpha-G1 and alpha-Ab-alpha-G2 exhibited competitive-type inhibition on human tyrosinase as alpha-arbutin does. Their K(i) values were calculated to be 0.6 mM and 2.8 mM, respectively, which is slightly and significantly higher than that of alpha-arbutin (0.2 mM).

Topics: Arbutin; Bacillus; Cell Line, Tumor; Enzyme Activation; Enzyme Stability; Glycosides; Humans; Melanoma; Monophenol Monooxygenase; Peptides

We studied the inhibitory effects of 4-hydroxyphenyl alpha-glucopyranoside (alpha-arbutin) on melanogenesis in cultured human melanoma cells, HMV-II, and in a three-dimensional cultured human skin model. alpha-Arbutin showed no inhibitory effect on HMV-II cell growth at a concentration below 1.0 mM. Melanin synthesis in cells treated with alpha-arbutin at 0.5 mM decreased to 76% of that in non-treated cells. The cellular tyrosinase activity of HMV-II cells also significantly decreased, while the expression of its mRNA was not affected. Melanin synthesis in a human skin model was also evaluated by the macro- and microscopic observation of its pigmentation as well as by quantitative measurements of melanin. Treatment of the human skin model with 250 microg of alpha-arbutin did not inhibit cell viability, while melanin synthesis was reduced to 40% of that in the control. These results indicate that alpha-arbutin is an effective and safe ingredient for skin-lightening.

Topics: Arbutin; Cell Division; Enzyme Inhibitors; Humans; Melanins; Melanoma; Models, Biological; Monophenol Monooxygenase; Organ Culture Techniques; Reverse Transcriptase Polymerase Chain Reaction; Skin; Tumor Cells, Cultured

The effects of 4-hydroxyphenyl alpha-glucopyranoside (alpha-arbutin) and 4-hydroxyphenyl beta-glucopyranoside (arbutin) on the activity of tyrosinase from human malignant melanoma cells were examined. The inhibitory effect of alpha-arbutin on human tyrosinase was stronger than that of arbutin. The K(i) value for alpha-arbutin was calculated to be 1/20 that for arbutin. We then synthesized arbutin-alpha-glycosides by the transglycosylation reaction of cyclomaltodextrin glucanotransferase using arbutin and starch, respectively, as acceptor and donor molecules. The structural analyses using 13C- and 1H-NMR proved that the transglycosylated products were 4-hydroxyphenyl beta-maltoside (beta-Ab-alpha-G1) and 4-hydroxyphenyl beta-maltotrioside (beta-Ab-alpha-G2). These arbutin-alpha-glycosides exhibited competitive type inhibition on human tyrosinase, and their K(i) values were calculated to be 0.7 mM and 0.9 mM, respectively. These arbutin-alpha-glycosides possessed stronger inhibitory activity than arbutin, but less activity than alpha-arbutin. These results suggested that the alpha-glucosidic linkage of hydroquinone-glycosides plays an important role in the inhibitory effect on human tyrosinase.

Topics: Arbutin; Enzyme Inhibitors; Humans; Melanoma; Monophenol Monooxygenase; Tumor Cells, Cultured

In this study, we present evidence that cotreatment of aloesin and arbutin inhibits tyrosinase activity in a synergistic manner by acting through a different action mechanism. Aloesin or arbutin similarly inhibited enzyme activity of human- and mushroom-tyrosinases with an IC50 value of 0.1 or 0.04 mM, respectively. Lineweaver-Burk plots of the enzyme kinetics data showed that aloesin inhibited tyrosinase activity noncompetitively with a Ki value of 5.3 mM, whereas arbutin did it competitively (Maeda, 1996). We then examined whether cotreatment of these agents inhibits the tyrosinase activity in a synergistic manner. The results showed that 0.01 mM aloesin in the presence of 0.03 mM arbutin inhibited activity of mushroom by 80% of the control value and the reverse was also true. The inhibitory effects were calculated to be synergistic according to the Bürgi method. Taken together, we suggest that aloesin along with arbutin inhibits in synergy melanin production by combined mechanisms of noncompetitive and competitive inhibitions of tyrosinase activity.

Topics: Agaricales; Arbutin; Binding, Competitive; Chromones; Dose-Response Relationship, Drug; Drug Synergism; Enzyme Inhibitors; Glucosides; Humans; Melanoma; Monophenol Monooxygenase; Tumor Cells, Cultured

Neoagarobiose, a disaccharide, showed a higher hygroscopic ability than glycerol or hyaluronic acid, typical moisturizing reagents. Beside, neoagarobiose whitened B16 murine melanoma cells, and showed low cytotoxicity. Therefore neoagarobiose was a rare reagent showing both moisturizing and whitening effects.

Topics: Animals; Arbutin; Disaccharides; Melanoma; Mice; Pyrones; Skin Care; Tumor Cells, Cultured; Wettability

The effects of alpha- and beta-arbutin on the activity of tyrosinases from mushroom and mouse melanoma were examined. alpha-Arbutin was synthesized from hydroquinone and starch using glucoside synthetase (GSase). beta-Arbutin inhibited both tyrosinase activities from mushroom and mouse melanoma. alpha-Arbutin inhibited only the tyrosinase from mouse melanoma, 10 times as strongly as beta-arbutin. The IC50 of alpha-arbutin was 0.48 mM and its inhibitory mechanism was speculated to be mixed type inhibition, while that of beta-arbutin was noncompetitive.

Topics: Animals; Arbutin; Basidiomycota; Binding, Competitive; Chromatography, High Pressure Liquid; Hydroquinones; Levodopa; Magnetic Resonance Spectroscopy; Melanoma; Mice; Monophenol Monooxygenase; Starch