Identifying melanogenesis inhibitors from Cinnamomum subavenium with in vitro and in vivo screening systems by targeting the human tyrosinase

Discovery of Potent Cysteine-Containing Dipeptide Inhibitors against Tyrosinase: A Comprehensive Investigation of 20 × 20 Dipeptides in Inhibiting Dopachrome Formation

Tyrosinase is an essential copper-containing enzyme required for melanin synthesis. The overproduction and abnormal accumulation of melanin cause hyperpigmentation and neurodegenerative diseases. Thus, tyrosinase is promising for use in medicine and cosmetics. Our previous study identified a natural product, A5, resembling the structure of the dipeptide WY and apparently inhibiting tyrosinase. Here, we comprehensively estimated the inhibitory capability of 20 × 20 dipeptides against mushroom tyrosinase. We found that cysteine-containing dipeptides, directly blocking the active site of tyrosinase, are highly potent in inhibition; in particular, N-terminal cysteine-containing dipeptides markedly outperform the C-terminal-containing ones. The cysteine-containing dipeptides, CE, CS, CY, and CW, show comparative bioactivities, and tyrosine-containing dipeptides are substrate-like inhibitors. The dipeptide PD attenuates 16.5% melanin content without any significant cytotoxicity. This study reveals the functional role of cysteine residue positional preference and the selectivity of specific amino acids in cysteine-containing dipeptides against tyrosinase, aiding in developing skin-whitening products.

Biofunctional Constituents from Michelia compressa var. lanyuensis with Anti-Melanogenic Properties

Seven compounds were extracted and purified from the roots of Michelia compressavar. lanyuensis. These compounds are liriodenine, (−)-N-acetylanonaine, pressalanine A, p-dihydroxybenzaldehyde, 3,4-dihydroxybenzoic acid, (−)-bornesitol and β-sitostenone. These compounds were screened for anti-proliferation and anti-tyrosinase activities in B16F10 cells. Liriodenine, pressalanine A, (−)-bornesitol and β-sitostenone displayed cytotoxicity at high concentration (100 μM), but liriodenine (5 μM), (−)-N-acetylanonaine (10 μM), and β-sitostenone (5 μM) inhibit tyrosinase activity and reduce the melanin content in B16F10 cells without cytotoxicity, suggesting that liriodenine and β-sitostenone could be safe and potentially used in cosmetic skin whitening.

Exploring the potential of using algae in cosmetics

The applications of microalgae in cosmetic products have recently received more attention in the treatment of skin problems, such as aging, tanning and pigment disorders. There are also potential uses in the areas of anti-aging, skin-whitening, and pigmentation reduction products. While algae species have already been used in some cosmetic formulations, such as moisturizing and thickening agents, algae remain largely untapped as an asset in this industry due to an apparent lack of utility as a primary active ingredient. This review article focuses on integrating studies on algae pertinent to skin health and beauty, with the purpose of identifying serviceable algae functions in practical cosmetic uses.

Evaluation of Cinnamomum osmophloeum Kanehira extracts on tyrosinase suppressor, wound repair promoter, and antioxidant

Cinnamomum osmophloeum Kanehira belongs to the Lauraceae family of Taiwan's endemic plants. In this study, C. osmophloeum Kanehira extract has shown inhibition of tyrosinase activity on B16-F10 cellular system first. Whether extracts inhibited mushroom tyrosinase activity was tested, and a considerable inhibition of mushroom tyrosinase activity by in vitro assays was presented. Animal experiments of C. osmophloeum Kanehira were carried out by observing animal wound repair, and the extracts had greater wound healing power than the vehicle control group (petroleum jelly with 8% DMSO, w/v). In addition, the antioxidant capacity of C. osmophloeum Kanehira extracts in vitro was evaluated. We measured C. osmophloeum Kanehira extract's free radical scavenging capability, metal chelating, and reduction power, such as biochemical activity analysis. The results showed that a high concentration of C. osmophloeum Kanehira extract had a significant scavenging capability of free radical, a minor effect of chelating ability, and moderate reducing power. Further exploration of the possible physiological mechanisms and the ingredient components of skincare product for skin-whitening, wound repair, or antioxidative agents are to be done.

Discovery of highly potent tyrosinase inhibitor, T1, with significant anti-melanogenesis ability by zebrafish in vivo assay and computational molecular modeling

Tyrosinase is involved in melanin biosynthesis and the abnormal accumulation of melanin pigments leading to hyperpigmentation disorders that can be treated with depigmenting agents. A natural product T1, bis(4-hydroxybenzyl)sulfide, isolated from the Chinese herbal plant, Gastrodia elata, is a strong competitive inhibitor against mushroom tyrosinase (IC₅₀ = 0.53 μM, Ki = 58 ± 6 nM), outperforms than kojic acid. The cell viability and melanin quantification assay demonstrate that 50 μM of T1 apparently attenuates 20% melanin content of human normal melanocytes without significant cell toxicity. Moreover, the zebrafish in vivo assay reveals that T1 effectively reduces melanogenesis with no adverse side effects. The acute oral toxicity study evidently confirms that T1 molecule is free of discernable cytotoxicity in mice. Furthermore, the molecular modeling demonstrates that the sulfur atom of T1 coordinating with the copper ions in the active site of tyrosinase is essential for mushroom tyrosinase inhibition and the ability of diminishing the human melanin synthesis. These results evident that T1 isolated from Gastrodia elata is a promising candidate in developing pharmacological and cosmetic agents of great potency in skin-whitening.

Polygonum cuspidatum extracts as bioactive antioxidaion, anti-tyrosinase, immune stimulation and anticancer agents

In our study, it was applied for the technology of supercritical fluid carbon dioxide extraction to achieve biological constitutes from a Taiwan native plant, Polygonum cuspidatum. We developed bioactive effects of P. cuspidatum extracts via multiple examinations that established bio-purposes at a range of dosage ranges. The research of P. cuspidatum extracts indicated that they possessed anti-oxidative properties on radical-scavenging abilities, reducing activities and metal chelating powers in dose-dependant manners. The extracts also had minor in vitro mushroom tyrosinase suppression and decreased cellular tyrosinase activities and melanin production in B16-F10 cells. Immunologically, P. cuspidatum extracts enhanced the release of tumor necrosis factor α (TNF-α) induced by THP-1 macrophage cell line. In addition, the cell proliferation showed anti-proliferation in dose-dependent manner on human skin melanoma cells, A375 and A375.S2, of the extracts suggesting biological constitutes employed the anti-cancer possessions. This is the first statement presenting bioactivities on P. cuspidatum extracts including anti-oxidation, immune stimulation, anti-tyrosinase and anti-melanoma as far as we know.

Poly-γ-glutamate from Bacillus subtilis inhibits tyrosinase activity and melanogenesis

Poly-γ-glutamate (γ-PGA) has been considered as one of the most promising biomaterials with a wide range of applications, but there has been no report that directly shows the anti-tyrosinase and anti-melanogenesis properties of γ-PGA. In the present study, we investigated the inhibitory effects of γ- PGA with low molecular weight (Mw; lγ-PGA) and high Mw (hγ-PGA) on mushroom tyrosinase and murine tyrosinase activities and on melanogenesis in B16 melanoma cells. First, we showed that both lγ-PGA and hγ-PGA could effectively inhibit mushroom tyrosinase activities including monophenolase and diphenolase activities in a dose-dependent manner. Second, both lγ-PGA and hγ-PGA showed strong anti-tyrosinase activity and anti-melanogenesis in B16 melanoma cells. Third, both lγ-PGA and hγ-PGA inhibited forskolin-induced tyrosinase activity and melanogenesis by decreasing the levels of intracellular reactive oxygen species and nitric oxide while increasing the catalase activity in B16 cells. This is the first report on the anti-melanogenesis effect of γ-PGA, which suggests that γ-PGA could have a potential in the cosmetic skin whitening business, therapeutic applications and the food industry.

Assessment of Cuscuta chinensis seeds׳ effect on melanogenesis: comparison of water and ethanol fractions in vitro and in vivo

ETHNOPHARMACOLOGICAL RELEVANCE

Cuscuta chinensis seeds have traditionally been used to treat freckles and melasma in Asia, although recent reports have revealed that Semen cuscutae is a promoter of melanogenesis. The present study aims to investigate the mechanism of this opposite effect of Semen cuscutae on melanogenesis.

MATERIALS AND METHODS

In accordance with traditional usage, the water fraction and the ethanol fraction from Semen cuscutae (WFSC/EFSC) were extracted to determine the herbal effects by examining the activity of mushroom tyrosinase, cellular melanin contents, tyrosinase activity assay, quantitative-reverse transcription polymerase chain reaction (qRT-PCR), and Western blot analysis for tyrosinase in B16F10 mouse melanoma cells. The melanocyte phenotypes of zebrafish larvae were observed while the in vivo melanin contents and tyrosinase activity were determined.

RESULTS

The activity of mushroom tyrosinase assay shown that WFSC was an uncompetitive inhibitor of mushroom tyrosinase, while EFSC indicated dose-dependent activation of the mushroom tyrosinase activity. The WFSC markedly inhibited 3-isobutyl-1-methylxanthine (IBMX)-stimulated melanin synthesis and tyrosinase activity in vitro. Howeveran accelerant role in melanin synthesis and tyosinase activity. Neither fraction had any effect on the IBMX-induced expression of tyrosinase protein or mRNA. The WFSC strongly inhibited melanin synthesis and cellular tyrosinase activity in vivo. Furthermore, with the function of WFSC at a higher concentration, a punctate melanocyte pattern appeared that was similar to the pattern induced by arbutin or Mequinol (MQ). The EFSC had no effect on the melanocytes of zebrafish larvae. It was discovered that WFSC did not show a stable inhibitory effect until it was extracted 1 month later.

CONCLUSIONS

These results suggest that the opposite effects of Cuscuta chinensis seeds were caused by the extraction methods and that time has an important role on the effect of WFSC. Both WFSC and EFSC significantly influence melanogenesis by regulating enzymatic activity of tyrosinase. In addition, the data indicate that wildtype (WT) zebrafish may be an ideal model for testing inhibitors of melanogenesis from clinically active herbs.

Isophilippinolide A arrests cell cycle progression and induces apoptosis for anticancer inhibitory agents in human melanoma cells

Three new butanolides, isophilippinolide A, philippinolide A, and philippinolide B, and an amide, cinnaretamine, were isolated from the roots of Cinnamomum philippinense to be identified by spectroscopic analysis. Four isolated compounds were screened to examine their radical-scavenging ability, metal-chelating power, and ferric-reducing antioxidant power assay (FRAP). Cinnaretamine showed powerful antioxidative properties in the 1,1-diphenyl-2-picrylhydrazyl (DPPH) assay and a reducing activity; all compounds presented minor inhibition of metal-chelating capacities. The effects of anti-tyrosinase of C. philippinense constituents were determined by the level of the suppression of hydroxylation that turned from L-tyrosine to L-dopa through an in vitro mushroom tyrosinase assay, and all testing samples illustrated slight mushroom tyrosinase inhibitory properties. Isophilippinolide A exhibited inhibitory effectivenesses against the A375.S2 melanoma cell line in a cell viability assay at concentrations ranging from 0 to 200 μM for 24 h. Propidium iodide staining and flow cytometry analyses were applied to assess cell cycle accumulative distribution. It was discovered that isophilippinolide A caused sub-G1 phase accumulation in positive correlation for apoptosis to inhibit cell growth. Further investigation revealed that isophilippinolide A induced A375.S2 cells with an increase of caspase-dependent apoptotic proteins to trigger correlated pathway mechanisms according to Western blotting results. Finally, isophilippinolide A displayed only low cytotoxicities to human normal epidermal cells (melanocytes) and dermal cells (fibroblasts). Altogether, the results implied C. philippinense compounds could be considered functional ingredients in cosmetics, foods, and pharmaceutical products, particularly for their anticancer ability on human skin melanoma cells.

Antimelanoma and antityrosinase from Alpinia galangal constituents

Two compounds, 1,7-bis(4-hydroxyphenyl)-1,4,6-heptatrien-3-one (BHPHTO) and bisdemethoxycurcumin (BDMC) they have been isolated from the rhizomes of Alpinia galangal, and the structures of both pure constituents were determined using spectroscopic analyses. The study examined the bioeffectivenesses of the two compounds on the human melanoma A2058 and showed that significantly inhibited the proliferation of melanoma cells in the cell viability assay. This research was also taken on the tests to B16-F10 cell line and showed minor inhibitory consequences of cellular tyrosinase activities and melanin contents. Our results revealed the anticancer effects of A. galangal compounds, and therefore, the target compounds could be potentially applied in the therapeutic application and the food industry.

Functional ginger extracts from supercritical fluid carbon dioxide extraction via in vitro and in vivo assays: antioxidation, antimicroorganism, and mice xenografts models

Supercritical fluid carbon dioxide extraction technology was developed to gain the active components from a Taiwan native plant, Zingiber officinale (ginger). We studied the biological effects of ginger extracts via multiple assays and demonstrated the biofunctions in each platform. Investigations of ginger extracts indicated antioxidative properties in dose-dependant manners on radical scavenging activities, reducing powers and metal chelating powers. We found that ginger extracts processed moderate scavenging values, middle metal chelating levels, and slight ferric reducing powers. The antibacterial susceptibility of ginger extracts on Staphylococcus aureus, Streptococcus sobrinus, S. mutans, and Escherichia coli was determined with the broth microdilution method technique. The ginger extracts had operative antimicroorganism potentials against both Gram-positive and Gram-negative bacteria. We further discovered the strong inhibitions of ginger extracts on lethal carcinogenic melanoma through in vivo xenograft model. To sum up, the data confirmed the possible applications as medical cosmetology agents, pharmaceutical antibiotics, and food supplements.

Novel biodegradable porous scaffold applied to skin regeneration

Skin wound healing is an important lifesaving issue for massive lesions. A novel porous scaffold with collagen, hyaluronic acid and gelatin was developed for skin wound repair. The swelling ratio of this developed scaffold was assayed by water absorption capacity and showed a value of over 20 g water/g dried scaffold. The scaffold was then degraded in time- and dose-dependent manners by three enzymes: lysozyme, hyaluronidase and collagenase I. The average pore diameter of the scaffold was 132.5±8.4 µm measured from SEM images. With human skin cells growing for 7 days, the SEM images showed surface fractures on the scaffold due to enzymatic digestion, indicating the biodegradable properties of this scaffold. To simulate skin distribution, the human epidermal keratinocytes, melanocytes and dermal fibroblasts were seeded on the porous scaffold and the cross-section immunofluorescent staining demonstrated normal human skin layer distributions. The collagen amount was also quantified after skin cells seeding and presented an amount 50% higher than those seeded on culture wells. The in vivo histological results showed that the scaffold ameliorated wound healing, including decreasing neutrophil infiltrates and thickening newly generated skin compared to the group without treatments.

Inhibitory Effect of Arctigenin from Fructus Arctii Extract on Melanin Synthesis via Repression of Tyrosinase Expression

To identify the active compound arctigenin in Fructus Arctii (dried seed of medicinal plant Arctium lappa) and to elucidate the inhibitory mechanism in melanogenesis, we analyzed melanin content and tyrosinase activity on B16BL6 murine melanoma and melan-A cell cultures. Water extracts of Fructus Arctii were shown to inhibit tyrosinase activity in vitro and melanin content in α-melanocyte stimulating hormone-stimulated cells to similar levels as the well-known kojic acid and arbutin, respectively. The active compound arctigenin of Fructus Arctii displayed little or no cytotoxicity at all concentrations examined and decreased the relative melanin content and tyrosinase activity in a dose-dependent manner. Melanogenic inhibitory activity was also identified in vivo with zebrafish embryo. To determine the mechanism of inhibition, the effects of arctigenin on tyrosinase gene expression and tyrosinase promoter activity were examined. Also in addition, in the signaling cascade, arctigenin dose dependently decreased the cAMP level and promoted the phosphorylation of extracellular signal-regulated kinase. This result suggests that arctigenin downregulates cAMP and the tyrosinase enzyme through its gene promoter and subsequently upregulates extracellular signal-regulated kinase activity by increasing phosphorylation in the melanogenesis signaling pathway, which leads to a lower melanin content.

Synthesis and biological evaluation of unsymmetrical curcumin analogues as tyrosinase inhibitors

Synthesis and biological evaluation of unsymmetrical curcumin analogues (UCAs) have been achieved. Tyrosinase inhibitory activities were found for most of the prepared synthetic UCAs. Among them, compounds containing 4-hydroxyl-substituted phenolic rings with C-2/C-4- or C-3/C-4-dihydroxyl-substituted diphenolic rings were more active (IC₅₀ = 1.74~16.74 μM) than 4-butylresorcinol and kojic acid, which suggested that the 4-hydroxyl groups in UCAs play a crucial role in tyrosinase inhibitory activities. The inhibition kinetics analyzed by Lineweaver-Burk plots revealed compounds 3c and 3i containing catecholic rings were mixed-competitive inhibitors, whereas compounds 3d and 3j containing resorcinolic rings were competitive inhibitors. The preliminary evaluation results of acute toxicity showed the representative 3d and 3j were non-toxic in mice dosed at 1,200 mg/kg. This research suggests that, with the advantage of being readily prepared small molecules, polyphenolic UCAs have the potential to develop into pharmacological inhibitors of tyrosinase.

Subamolide B Isolated from Medicinal Plant Cinnamomum subavenium Induces Cytotoxicity in Human Cutaneous Squamous Cell Carcinoma Cells through Mitochondrial and CHOP-Dependent Cell Death Pathways

Subamolide B is a butanolide isolated from Cinnamomum subavenium, a medicinal plant traditionally used to treat various ailments including carcinomatous swelling. We herein reported for the first time that subamolide B potently induced cytotoxicity against diverse human skin cancer cell lines while sparing nonmalignant cells. Mechanistic studies on human cutaneous squamous cell carcinoma (SCC) cell line SCC12 highlighted the involvement of apoptosis in subamolide B-induced cytotoxicity, as evidenced by the activation of caspases-8, -9, -4, and -3, the increase in annexin V-positive population, and the partial restoration of cell viability by cotreatment with the pan-caspase inhibitor z-VAD-fmk. Additionally, subamolide B evoked cell death pathways mediated by FasL/Fas, mitochondria, and endoplasmic reticulum (ER) stress, as supported by subamolide B-induced FasL upregulation, BCL-2 suppression/cytosolic release of cytochrome c, and UPR activation/CHOP upregulation, respectively. Noteworthy, ectopic expression of c-FLIP_L or dominant-negative mutant of FADD failed to impair subamolide B-induced cytotoxicity, whereas BCL-2 overexpression or CHOP depletion greatly rescued subamolide B-stimulated cells. Collectively, these results underscored the central role of mitochondrial and CHOP-mediated cell death pathways in subamolide B-induced cytotoxicity. Our findings further implicate the potential of subamolide B for cutaneous SCC therapy or as a lead compound for developing novel chemotherapeutic agents.

Enhancements of skin cell proliferations and migrations via 6-dehydrogingerdione

Human skin protects the body from mechanical and chemical damages, and skin wound healing is a costly procedure and worldwide issue. A Zingiber officinale compound, 6-dehydrogingerdione (6-DG), is presented as a novel biofunctional healing agent for human skin wound repair. The effectiveness on cell growth/migration, growth factor, collagen amount, and enzymatic activity was assessed. 6-DG treatment accelerated cellular proliferation and migration dose-dependently. Enzyme-linked immunosorbent assay (ELISA) showed that 6-DG brought about higher growth factor productions on transforming growth factor-β (TGF-β), platelet-derived growth factor-αβ (PDGF-αβ), and vascular endothelial growth factors (VEGF). Under phorbol 12-myristate 13-acetate (PMA) incubation, 6-DG increased fibroblast collagen yield obviously, reduced matrix metalloproteinase-1 (MMP-1) protein expression, and recovered tissue inhibitor of metalloproteinase-1 (TIMP-1) secretion. 6-DG also blocked the mitogen-activated protein kinase (MAPK) pathway by suppressing c-Jun protein levels and extracellular signal-regulated kinases (ERK) phosphorylation in fibroblasts. From all of the above, 6-DG has potential to be a novel agent for human skin repair.

Biofunctional constituents from Liriodendron tulipifera with antioxidants and anti-melanogenic properties

From the stems of Liriodendron tulipifera, seventeen known compounds have been extracted, isolated and purified. By using spectroscopic analysis, the structures of these pure constituents were determined as three lignans, four steroids and ten benzenoids. Identified compounds were screened for antioxidant abilities using: 1,1-diphenyl-2-picrylhydrazul (DPPH) and 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) scavenging free radical activity assays; metal chelating power test; and ferric reducing/antioxidant power (FRAP) examination. The result revealed that seventeen compounds had potential anti-oxidative capabilities. In addition, the anti-tyrosinase effect was determined by calculating the hydroxylation of L-tyrosine to L-dopa and the oxidization of L-dopa to dopaquinone, according to in vitro mushroom tyrosinase evaluation platform. Furthermore, based on assays on B16F10 cell line, our data suggest that five compounds isolated from L. tulipifera would be able to inhibit tyrosinase activity and reduce the melanin content in animal cells. Therefore, some of the examined compounds could be potentially used in the cosmetic skin whitening business, therapeutic applications or the food industry.

Up-regulation of melanin synthesis by the antidepressant fluoxetine

Fluoxetine, a member of the class of selective serotonin reuptake inhibitors, is a potent antidepressant commonly used in clinical practice. Here, we report that fluoxetine increases cellular tyrosinase (TYR) activity, enhances the protein levels of microphthalmia-associated transcription factor (MITF), TYR and tyrosinase-related protein-1 (TRP-1) and eventually leads to a dramatic increase in melanin production in both murine B16F10 melanoma cells and normal human melanocytes (NHMCs). In well-characterized C57BL/6 mouse models, systemic application of fluoxetine increased hair pigmentation by up-regulating hair follicular MITF, TYR, TRP-1 and tyrosinase-related protein-2 (TRP-2) protein levels. Using a serotonin 1A receptor (SR1A) antagonist and RNA interference (RNAi) technique, we revealed that SR1A appears to be one of the involved pathways in the fluoxetine-induced melanogenesis in B16F10 cells. These results suggest that fluoxetine may hold a significant therapeutic potential for treating skin hypopigmentation disorders, and SR1A may serve as a novel target in modulating melanogenesis.

Natural Melanogenesis Inhibitors Acting Through the Down-Regulation of Tyrosinase Activity

Melanogenesis is a biosynthetic pathway for the formation of the pigment melanin in human skin. A key enzyme, tyrosinase, catalyzes the first and only rate-limiting steps in melanogenesis, and the down-regulation of enzyme activity is the most reported method for the inhibition of melanogenesis. Because of the cosmetically important issue of hyperpigmentation, there is a big demand for melanogenesis inhibitors. This encourages researchers to seek potent melanogenesis inhibitors for cosmetic uses. This article reviews melanogenesis inhibitors that have been recently discovered from natural sources. The reaction mechanisms of the inhibitors on tyrosinase activity are also discussed.

Synthesis, biological evaluation, and molecular docking of N-{3-[3-(9-methyl-9H-carbazol-3-yl)-acryloyl]-phenyl}-benzamide/amide derivatives as xanthine oxidase and tyrosinase inhibitors

Claisen-Schmidt condensation of 3-formyl-9-methylcarbazole with various amides of 3-aminoacetophenone afforded N-{3-[3-(9-methyl-9H-carbazol-3-yl)-acryloyl]-phenyl}-benzamide/amide derivatives. All compounds were investigated for their in vitro xanthine oxidase (XO), tyrosinase and melanin production inhibitory activity. Most of the target compounds had more potent XO inhibitory activity than the standard drug (IC(50) = 4.3-5.6 μM). Interestingly, compound 7q bearing cyclopropyl ring was found to be the most potent inhibitor of XO (IC(50) = 4.3 μM). Molecular modelling study gave an insight into its binding modes with XO. Compounds 7a, 7d, 7e, 7g, and 7k were found to be potent inhibitors of tyrosinase (IC(50) = 14.01-17.52 μM). These results suggest the possible use of these compounds for the design and development of novel XO and tyrosinase inhibitors.

Review on pharmacological activities of Cinnamomum subavenium

This review describes the morphological, phytochemical and pharmacological properties of Cinnamomum subavenium (Lauraceae). The plant grows wild in southern Mainland China, Burma, Cambodia, Taiwan, Malaysia and Indonesia. This plant is recorded as having long been used to treat carcinomatous swelling, stomach ache, chest pain, abdominal pain, hernia, diarrhoea, rheumatism, nausea and vomiting. This article enumerates an overview of phytochemical and pharmacological aspects that is useful to researchers for further exploration for the necessary development of this potential herb.

Biological properties of acidic cosmetic water from seawater

This current work was to investigate the biological effects of acidic cosmetic water (ACW) on various biological assays. ACW was isolated from seawater and demonstrated several bio-functions at various concentration ranges. ACW showed a satisfactory effect against Staphylococcus aureus, which reduced 90% of bacterial growth after a 5-second exposure. We used cultured human peripheral blood mononuclear cells (PBMCs) to test the properties of ACW in inflammatory cytokine release, and it did not induce inflammatory cytokine release from un-stimulated, normal PBMCs. However, ACW was able to inhibit bacterial lipopolysaccharide (LPS)-induced inflammatory cytokine TNF-α released from PBMCs, showing an anti-inflammation potential. Furthermore, ACW did not stimulate the rat basophilic leukemia cell (RBL-2H3) related allergy response on de-granulation. Our data presented ACW with a strong anti-oxidative ability in a superoxide anion radical scavenging assay. In mass spectrometry information, magnesium and zinc ions demonstrated bio-functional detections for anti-inflammation as well as other metal ions such as potassium and calcium were observed. ACW also had minor tyrosinase and melanin decreasing activities in human epidermal melanocytes (HEMn-MP) without apparent cytotoxicity. In addition, the cell proliferation assay illustrated anti-growth and anti-migration effects of ACW on human skin melanoma cells (A375.S2) indicating that it exerted the anti-cancer potential against skin cancer. The results obtained from biological assays showed that ACW possessed multiple bioactivities, including anti-microorganism, anti-inflammation, allergy-free, antioxidant, anti-melanin and anticancer properties. To our knowledge, this was the first report presenting these bioactivities on ACW.

Bio-functional constituents from the stems of Liriodendron tulipifera

Four known compounds have been isolated from the stems of Liriodendron tulipifera, and the structures of these pure constituents were determined using spectroscopic analysis. Isolated compounds were screened for free radical scavenging ability, metal chelating power assay and ferric reducing antioxidant power assay (FRAP). The anti-tyrosinase effects of L. tulipifera compounds were calculated the inhibition of hydroxylation of L-tyrosine to L-dopa according to an in vitro mushroom tyrosinase assay. The study also examined the bio-effects of the four compounds on the human melanoma A375.S2, and showed that liriodenine (1) and (-)-norglaucine (4) significantly inhibited the proliferation of melanoma cells in the cell viability assay. Wound healing results indicated that liriodenine (1), (-)-glaucine (3) and (-)-norglaucine (4) exerted anti-migration potential. Interestingly, (-)-glaucine (3), neither liriodenine (1) nor (-)-norglaucine (4) showed promising anti-migration potential without inducing significant cytotoxicity. Furthermore, a dramatically increased level of intracellular reactive oxygen species (ROS) was detected from (-)-glaucine (3). The cell cycle assessment demonstrated a moderate G2/M accumulation by (-)-glaucine (3). The above results revealed the anti-cancer effects of L. tulipifera compounds, especially on the anti-migration ability indicating the promising chemopreventive agents to human skin melanoma cells.

10-Shogaol, an antioxidant from Zingiber officinale for skin cell proliferation and migration enhancer

In this work, one of Zingiber officinale components, 10-shogaol, was tested with 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging, metal chelating ability, and reducing power to show antioxidant activity. 10-Shogaol promoted human normal epidermal keratinocytes and dermal fibroblasts cell growths. 10-Shogaol enhanced growth factor production in transforming growth factor-β (TGF-β), platelet derived growth factor-αβ (PDGF-αβ) and vascular endothelial growth factors (VEGF) of both cells. In the in vitro wound healing assay for 12 or 24 h, with 10-shogaol, the fibroblasts and keratinocytes migrated more rapidly than the vehicle control group. Thus, this study substantiates the target compound, 10-shogaol, as an antioxidant for human skin cell growth and a migration enhancer with potential to be a novel wound repair agent.

Modulation of skin pigmentation by the tetrapeptide PKEK: in vitro and in vivo evidence for skin whitening effects

Uneven skin pigmentation is a significant cosmetic concern, and the identification of topically applicable molecules to address this issue is of general interest. We report that the tetrapeptide PKEK (Pro-Lys-Glu-Lys) can exert skin whitening effects based on one in vitro and four double-blinded vehicle-controlled in vivo studies. (i) Treatment of human keratinocytes with PKEK significantly reduced UVB-stimulated mRNA expression of interleukin (IL)-6, IL-8 and TNF-α and, most importantly, proopiomelanocorticotropin (POMC), i.e. a gene encoding the pigmentation-inducing soluble mediator α- (α-MSH). (ii) PKEK treatment significantly inhibited UVB-induced upregulation of genes encoding for IL-1α, IL-6, IL-8, TNF-α as well as POMC and tyrosinase in 10 healthy volunteers pretreated with PKEK for 4 weeks once daily. (iii) In a study enrolling 39 Caucasian women, facial pigment spots significantly faded after 6 weeks when PKEK was combined with the skin whitener sodium ascorbyl phosphate (SAP), whereas PKEK or SAP alone led to less pronounced fading of the pigment spots. (iv) Addition of PKEK enhanced the skin whitening potency of a SAP-containing preparation if applied for 8 weeks to the back of hands of 19 Caucasians. (v) 27 Japanese women were treated on their faces twice daily with an SAP only or a PKEK+SAP-containing formulation for 8 weeks. Application of PKEK+SAP significantly reduced skin pigmentation by 26% and by 18% according to SCINEXA score. We demonstrate that PKEK has the capacity to reduce UVB-induced skin pigmentation and may be suited to serve as a skin tone-modulating agent in cosmetic products.

Subamolide A, a component isolated from Cinnamomum subavenium, induces apoptosis mediated by mitochondria-dependent, p53 and ERK1/2 pathways in human urothelial carcinoma cell line NTUB1

ETHNOPHARMACOLOGICAL RELEVANCE

Cinnamomum subavenium has long been used as a traditional Chinese medicine to treat carcinomatous swelling, abdominal pain and other diseases.

AIM OF THE STUDY

The goal of this work was to study the cytotoxic effect of subamolide A, a constituent isolated from the stems of Cinnamomum subavenium Miq., and to extend its traditional use for clinical applications in treating human urothelial carcinoma.

MATERIALS AND METHODS

Cytotoxic effect of subamolide A was determined by the MTT assay in NTUB1, T24, PC3 and SV-HUC-1 cells treated with various concentrations of subamolide A for three days. Apoptosis was detected by the change of cell morphology and flow cytometry analysis. The reactive oxygen species (ROS) level and mitochondria membrane potential (Δψm) were determined by flow cytometry. Western blot analysis was used to quantify the expression of apoptosis-related and stress-induced signaling molecules.

RESULTS

Subamolide A selectively induced apoptosis in two cancerous human urothelial carcinoma cell lines (NTUB1 and T24) in comparison with normal immortalized uroepithelial cells (SV-HUC-1). Subamolide A reduced mitochondrial membrane potential (Δψm) and caused apoptosis of NTUB1 cells. Subamolide A increased Bax/Bcl-2 ratios, the amount of cytochrome c released from the mitochondria, caspase-3 and PARP cleavage, activated p53 and ERK1/2 and ultimately led to apoptosis in NTUB1 cells. Furthermore, a higher dose (10μM) of subamolide A synergistically enhanced the cytotoxicity of cisplatin and gemcitabine in NTUB1 cells.

CONCLUSIONS

The current study demonstrated that subamolide A triggered the mitochondria-dependent apoptotic pathways and p53 and ERK1/2 activation in the human urothelial carcinoma cell line NTUB1. In addition, subamolide A synergistically enhanced cytotoxic effect of CDDP and Gem in NTUB1. These data suggested that subamolide A exhibited a potent anti-proliferation activity. This study supports the traditional use of Cinnamomum subavenium stems with a therapeutic potential for the treatment of human urothelial carcinoma.

Subamolide E from Cinnamomum subavenium induces sub-G1 cell-cycle arrest and caspase-dependent apoptosis and reduces the migration ability of human melanoma cells

The aim of this work was to investigate the anticancer cytotoxic effects of natural compound subamolide E on the human skin cancer melanoma A375.S2 cells. Subamolide E was isolated from Cinnamomum subavenium and demonstrated cytotoxicities in the cell-growth assay at concentration ranges from 0 to 100 μM at 24 h. Propidium iodide staining and flow cytometry analyses were used to evaluate cell-cycle distribution and found that subamolide E caused DNA damage in the sub-G1 phase with a dose-dependent manner after 24 h of treatment. According to the western blot result, subamolide-E-treated cells with the increase of caspase-dependent apoptotic proteins induced related pathway mechanisms. Subamolide E also showed antimigratory activities of A375.S2 cells on the wound-healing assay. Finally, subamolide E demonstrated minor cytotoxicities to normal human skin cells (keratinocytes, melanocytes, and fibroblasts); therefore, it is a potential chemotherapeutic agent against skin melanoma.

Ov-16 [4-(3,4-dihydroxybenzoyloxymethyl)phenyl-O-β-D-glucopyranoside] inhibits melanin synthesis by regulating expressions of melanogenesis-regulated gene and protein

Ov-16 (4-(3,4-dihydroxybenzoyloxymethyl)phenyl-O-β-D-glucopyranoside), a polyphenolic glycoside that is isolated from oregano (Origanum vulgare L.), can scavenge 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radicals. This investigation is the first to study in detail the hypopigmentary properties of Ov-16. It demonstrates that 0-1000 μg/ml Ov-16 inhibits the activity of mushroom tyrosinase (Tyr) in a concentration-dependent manner. The inhibitionary Tyr kinetics of Ov-16 towards the oxidation of L-DOPA was found to be uncompetitive. Following the treatment of human skin premalignant kerationcyte HaCaT cells, human skin fibroblast Hs68 cells and mice melanoma B16 cells with Ov-16 (0-100 μg/ml), cell viability was >98%, suggesting that Ov-16 is non-toxic. Ov-16 can reduce cellular Tyr activity, DOPA oxidase activity and melanin synthesis in B16 cells that are stimulated by the α-melanocyte-stimulating hormone (α-MSH). Moreover, Ov-16 inhibited the production of melanin in Streptomyces bikiniensis without affecting the growth of the microorganism. The treatment of B16 cells with Ov-16 considerably reduced the gene expressions of melanocortin-1 receptor (Mc1r), microphthalmia-associated transcription factor (Mitf), Tyr, tyrosinase-related proteins-2 (Trp-2) and Trp-1, as determined by RT-PCR. The expressions of Mc1r, Mift, Tyr, Trp-2 and TrpP-1 protein in Ov-16-treated B16 cells were also significantly reduced, as determined by western blotting and fluorescent staining analysis. These results suggest that Ov-16 exhibits hypopigmentary performance.

Inhibitory effect of phthalic Acid on tyrosinase: the mixed-type inhibition and docking simulations

Tyrosinase inhibition studies are needed due to the medicinal applications such as hyperpigmentation. For probing effective inhibitors of tyrosinase, a combination of computational prediction and enzymatic assay via kinetics was important. We predicted the 3D structure of tyrosinase, used a docking algorithm to simulate binding between tyrosinase and phthalic acid (PA), and studied the reversible inhibition of tyrosinase by PA. PA inhibited tyrosinase in a mixed-type manner with a K_i = 65.84 ± 1.10 mM. Measurements of intrinsic and ANS-binding fluorescences showed that PA induced changes in the active site structure via indirect binding. Simulation was successful (binding energies for Dock6.3 = −27.22 and AutoDock4.2 = −0.97 kcal/mol), suggesting that PA interacts with LEU73 residue that is predicted commonly by both programs. The present study suggested that the strategy of predicting tyrosinase inhibition based on hydroxyl groups and orientation may prove useful for screening of potential tyrosinase inhibitors.