Afzelin positively regulates melanogenesis through the p38 MAPK pathway

Germacrone, isolated from Curcuma wenyujin, inhibits melanin synthesis through the regulation of the MAPK signaling pathway

Abnormal melanin synthesis causes hyperpigmentation disorders, such as chloasma, freckles, and melanoma, which are highly multiple and prevalent. There were few reports on the anti-melanogenic effect of Curcuma wenyujin Y.H. Chen et C. Ling, and the bioactive compound has not been elucidated as well. The study aims to investigate the anti-melanogenic effect of C. wenyujin, and identify the bioactive compound, and further explore its underlying mechanism. Our results showed that the Petroleum ether fraction extracted from C. wenyujin rhizome had a significant anti-melanogenic effect, and germacrone isolated from it was confirmed as the major bioactive compound. To our data, germacrone significantly inhibited tyrosinase (TYR) activity, reduced melanosome synthesis, reduced dendrites formation of B16F10 cells, and melanosome transport to keratinocytes. Moreover, germacrone effectively decreased the hyperpigmentation in zebrafish and the skin of guinea pigs in vivo. Western-blot analysis showed that germacrone down-regulated the expression of TYR, TRP-1, TRP-2, Rab27a, Cdc42, and MITF proteins via the activation of the MAPK signaling pathway. Taken together, germacrone is an effective bioactive compound for melanogenesis inhibition. Our studies suggest that germacrone may be considered a potential candidate for skin whitening.

Polyphenols targeting multiple molecular targets and pathways for the treatment of vitiligo

Vitiligo, a pigmentary autoimmune disorder, is marked by the selective loss of melanocytes in the skin, leading to the appearance of depigmented patches. The principal pathological mechanism is the melanocyte destruction mediated by CD8+ T cells, modulated by oxidative stress and immune dysregulation. Vitiligo affects both physical health and psychological well-being, diminishing the quality of life. Polyphenols, naturally occurring compounds with diverse pharmacological properties, including antioxidant and anti-inflammatory activities, have demonstrated efficacy in managing various dermatological conditions through multiple pathways. This review provides a comprehensive analysis of vitiligo and the therapeutic potential of natural polyphenolic compounds. We examine the roles of various polyphenols in vitiligo management through antioxidant and immunomodulatory effects, melanogenesis promotion, and apoptosis reduction. The review underscores the need for further investigation into the precise molecular mechanisms of these compounds in vitiligo treatment and the exploration of their combination with current therapies to augment therapeutic outcomes.

Petanin Potentiated JNK Phosphorylation to Negatively Regulate the ERK/CREB/MITF Signaling Pathway for Anti-Melanogenesis in Zebrafish

Petanin, an acylated anthocyanin from the Solanaceae family, shows potential in tyrosinase inhibitory activity and anti-melanogenic effects; however, its mechanism remains unclear. Therefore, to investigate the underlying mechanism of petanin's anti-melanogenic effects, the enzyme activity, protein expression and mRNA transcription of melanogenic and related signaling pathways in zebrafish using network pharmacology, molecular docking and molecular dynamics simulation were combined for analysis. The results showed that petanin could inhibit tyrosinase activity and melanogenesis, change the distribution and arrangement of melanocytes and the structure of melanosomes, reduce the activities of catalase (CAT) and peroxidase (POD) and enhance the activity of glutathione reductase (GR). It also up-regulated JNK phosphorylation, inhibited ERK/RSK phosphorylation and down-regulated CREB/MITF-related protein expression and mRNA transcription. These results were consistent with the predictions provided through network pharmacology and molecular docking. Thus, petanin could inhibit the activity of tyrosinase and the expression of tyrosinase by inhibiting and negatively regulating the tyrosinase-related signaling pathway ERK/CREB/MITF through p-JNK. In conclusion, petanin is a good tyrosinase inhibitor and anti-melanin natural compound with significant market prospects in melanogenesis-related diseases and skin whitening cosmetics.

Whole-transcriptome sequencing reveals a melanin-related ceRNA regulatory network in the breast muscle of Xichuan black-bone chicken

The economic losses incurred due to reduced muscle pigmentation highlight the crucial role of melanin-based coloration in the meat of black-bone chickens. Melanogenesis in the breast muscle of black-bone chickens is currently poorly understood in terms of molecular mechanisms. This study employed whole-transcriptome sequencing to analyze black and white breast muscle samples from black-bone chickens, leading to the identification of 367 differentially expressed (DE) mRNAs, 48 DElncRNAs, 104 DEcircRNAs, and 112 DEmiRNAs involved in melanin deposition. Based on these findings, a competitive endogenous RNA (ceRNA) network was developed to better understand the complex mechanisms of melanin deposition. Furthermore, our analysis revealed key DEmRNAs (TYR, DCT, EDNRB, MLPH and OCA2) regulated by DEmiRNAs (gga-miR-140-5p, gga-miR-1682, gga-miR-3529, gga-miR-499-3p, novel-m0012-3p, gga-miR-200b-5p, gga-miR-203a, gga-miR-6651-5p, gga-miR-7455-3p, gga-miR-31-5p, miR-140-x, miR-455-x, novel-m0065-3p, gga-miR-29b-1-5p, miR-455-y, novel-m0085-3p, and gga-miR-196-1-3p). These DEmiRNAs competitively interacted with DElncRNAs including MSTRG.2609.2, MSTRG.4185.1, LOC112530666, LOC112533366, LOC771030, LOC107054724, LOC121107411, LOC100859072, LOC101750037, LOC121108550, LOC121109224, LOC121110876, and LOC101749016, as well as DEcircRNAs, such as novel_circ_000158, novel_circ_000623, novel_001518, and novel_circ_003596. The findings from this study provide insight into the mechanisms that regulate lncRNA, circRNA, miRNA, and mRNA expression in chicken melanin deposition.

Afzelin induces immunogenic cell death against lung cancer by targeting NQO2

BACKGROUND

Lung cancer is one of the most common malignant cancers worldwide. Previous studies have shown that Afzelin, a flavonoid, possesses anticancer activity. The aim of this study was to explore Afzelin's effect on lung cancer cells and delineate potential anti-cancer mechanism.

METHODS

The effect of Afzelin on cell viability, proliferation, and apoptosis of lung cancer cells i.e., A549 and H1299 cells, was studied. The targets for Afzelin in lung cancer were predicted using SwissTargetPrediction, Next, the GO analysis and pathway enrichment were analyzed using String. For in vitro studies, the overexpression plasmid of NQO2, the identified target of Afzelin, was transfected into Afzelin-treated cells to verify the regulatory role of Afzelin on its target and signaling pathway.

RESULTS

In in vitro studies, Afzelin markedly inhibited cell viability, proliferation, and raised apoptotic rate of A549 and H1299 cells. In addition, Afzelin activated endoplasmic reticulum (ER) stress and increased ATP, HMGB1, and CRT levels in lung cancer cells, indicating that Afzelin induced immunogenic cell death (ICD). SwissTargetPrediction identified NQO2 as a target of Afzelin. Further, Afzelin markedly inhibited NQO2 protein expression and in turn, overexpression of NQO2 attenuated the effect of Afzelin on A549 and H1299 cells.

CONCLUSION

Afzelin inhibits lung cancer progression by targeting NQO2, in turn, activating ER stress and inducing ICD.

Baicalein Inhibits α-Melanocyte-stimulating Hormone-stimulated Melanogenesis via p38 Mitogen-activated Protein Kinase Pathway in B16F10 Mouse Melanoma Cells

Excessive UVB exposure causes development of both malignant and non-malignant melanoma via the secretion of α-melanocyte-stimulating hormone (α-MSH). We investigated whether baicalein (5,6,7-trihydroxyflavone) could inhibit α-MSH-stimulated melanogenesis. Baicalein prevented UVB- and α-MSH-induced melanin production and attenuated α-MSH-stimulated tyrosinase (monophenol monooxygenase) activity, and expression of tyrosinase and tyrosine-related protein-2. In addition, baicalein prevented melanogenesis and pigmentation via the p38 mitogen-activated protein kinases signaling pathway. These findings suggest that baicalein represents a natural compound for attenuating melanogenesis.

Licorice zinc suppresses melanogenesis via inhibiting the activation of P38MAPK and JNK signaling pathway in C57BL/6J mice skin

PURPOSE

The active melanocytes in the skin were affected by hormones and ultraviolet (UV) irradiation. Licorice zinc has a whitening effect, which may have a prominent potential in the treatment of pigmented skin disease.

METHODS

Modeling chloasma C57BL/6J mice by daily progesterone injection (15 mg/kg) and ultraviolet B (UVB) irradiation (λ = 312 nm, 2 h/day) for 30 days. Then, mice were given 0.65, 1.3, and 2.6 (g/kg) of licorice zinc and tranexamic acid 250 mg daily by oral administration for 14 days, respectively. Hematoxylin and eosin and Fontana-Masson staining, and Western blotting (WB) were performed to test the inhibitory of melanogenesis and activation of c-Jun-N-terminal (JNK)/p38 mitogen-activated protein kinases (MAPK) for licorice zinc. Melanogenesis was induced by α-melanocyte-stimulating hormone in vitro. Cell counting kit-8, melanin content determination, and WB were performed to verify the inhibitory effect of licorice zinc on melanogenesis.

RESULTS

The present study showed that licorice zinc decreased melanin formation, cutaneous tissue injury, and the phosphorylation of JNK and P38MAPK, which was caused by UVB irradiation in vivo. In vitro, licorice zinc showed opposite effects from JNK/p38 activator. Meanwhile, tyrosinase-related protein-1, tyrosinase, and microphthalmia-associated transcription factor were decreased too.

CONCLUSIONS

Licorice zinc induced a decrease in melanin synthesis by inhibiting the JNK and the P38MAPK signaling pathway, suggesting licorice zinc is a potential agent of anti-chloasma.

Drug delivery of natural products through nano-carriers for effective vitiligo therapy: A compendia review

BACKGROUND

Vitiligo is a depigmenting illness that causes white areas on the skin. Vitiligo's pathogenetic genesis is based on the melanocyte's autoimmune destruction, in which oxidative stress causes melanocyte molecular, organelle, and exposure of antigen, as well as melanocyte cell death, and so plays a role in vitiligo progression. Natural compounds have recently shown a wide range of therapeutic bioactivities against a number of skin disorders.

AIM

The aim of this work is drug delivery of natural products through nano-carriers for effective vitiligo therapy: A compendia review.

METHODS & MATERIALS

An online literature analysis was guided for vitiligo therapy, nanotechnology, phytochemical composition, and, types of vitiligo, types of nanomedicine. Appropriate information were taken from different electronic scientific databases such as Web of Science, Science Direct, Elsevier, Google Scholar, Springer, PubMed, and scripts.

RESULTS

Nano-carriers-based natural compounds provide a great relationship for the enhancement in the efficacy and safety of pharmacotherapeutic agents for the treatment of vitiligo.

DISCUSSION

In this study focuses on natural compounds' effects and processes on vitiligo models. Although topical therapy plays an important role in vitiligo treatment, its utility and patient compliance are hampered by adverse effects or inadequate efficacy. Novel drug delivery techniques can help improve topical medication delivery by improving epidermal localization, reducing side effects, and increasing effectiveness.

CONCLUSION

This paper covers the significant potential of herbal-derived active compounds as anti-vitiligo drugs, as well as new drug delivery as a viable carrier and future possibilities to investigate.

Advances in Biomedical Functions of Natural Whitening Substances in the Treatment of Skin Pigmentation Diseases

Pigmentation diseases can lead to significant color differences between the affected part and the normal part, resulting in severe psychological and emotional distress among patients. The treatment of pigmentation diseases with good patient compliance is mainly in the form of topical drugs. However, conventional hydroquinone therapy contributes to several pathological conditions, such as erythema, dryness, and skin desquamation, and requires a longer treatment time to show significant results. To address these shortcomings, natural whitening substances represented by kojic acid and arbutin have gradually become the candidate ingredients of traditional local preparations due to their excellent biological safety. This review focuses on several natural whitening substances with potential therapeutic effects in pigmentation disease and their mechanisms, and a thorough discussion has been conducted into the solution methods for the challenges involved in the practical application of natural whitening substances.

Evaluation of the chemical profile from four germplasms sources of Pruni Semen using UHPLC-LTQ-Orbitrap-MS and multivariate analysis

Pruni Semen, the seed of several unique Prunus plants, is a traditional purgative herbal material. To determine the authentic sources of Pruni Semen, 46 samples from four species were collected and analyzed. Ten compounds including multiflorin A (Mul A), a notable purative compound, were isolated and identified by chemical separation and nuclear magnetic resonance spectroscopy. Seventy-six communal components were identified by ultra-high performance liquid chromatography with linear ion trap-quadrupole Orbitrap mass spectrometry, and acetyl flavonoid glycosides were recognized as characteristic constituents. The flavonoids were distributed in the seed coat and cyanogenic glycosides in the kernel. Based on this, methods for identifying Pruni Semen from different sources were established using chemical fingerprinting, quantitative analysis of the eight principal compounds, hierarchical cluster analysis, principal component analysis, and orthogonal partial least squares discriminant analysis. The results showed that the samples were divided into two categories: one is the small seeds from Prunus humilis (Ph) and Prunus japonica (Pj), and the other is the big seeds from Prunus pedunculata (Pp) and Prunus triloba (Pt). The average content of Mul A was 3.02, 6.93, 0.40, and 0.29 mg/g, while the average content of amygdalin was 18.5, 17.7, 31.5, and 30.9 mg/g in Ph, Pj, Pp, and Pt, respectively. All the above information suggests that small seeds might be superior sources of Pruni Semen. This is the first comprehensive report on the identification of chemical components in Pruni Semen from different species.

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Chemical constituents of Pruni semen from four Prunus species were compared.

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Acetyl flavonoid glycosides were identified as the characteristic components.

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Flavonoids were present in the seed coat and cyanogenic glycosides in the kernel.

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The content of acetyl flavonoid in small seeds is significant higher than those in big ones.

Keratinocytes take part in the regulation of substance P in melanogenesis through the HPA axis

BACKGROUND

Clinical findings have shown that skin depigmentation disorder such as vitiligo may be closely associated with the release of central and peripheral substance P (SP) resulted from chronic psychological stress or sudden mental blow. But the regulatory role of SP and its receptor, tachykinin receptor in the pathogenesis of vitiligo is unclear.

OBJECTIVES

To investigate the function and mechanism of SP in melanogenesis.

METHODS

The chronic mental stress was used to explore the intrinsic association between psychological factors, SP and melanogenesis disorder. The effect of SP on melanogenesis through hypothalamic pituitary adrenocortical (HPA) axis was studied by skin culture in vitro. The conditioned medium experiment demonstrated the indirect effect of SP on melanogenesis of B16F10 cells through HaCaT cells. The ability to produce melanin was evaluated by detecting melanin and tyrosinase activity. qRT-PCR, western blotting and immunohistochemistry were used to detect the expression of related genes and proteins in melanogenesis and HPA axis.

RESULTS

Increased SP expression and reduction of melanogenesis in the skin of mice were observed under mental stress. Melanogenesis was suppressed in the cultured human skin treated with SP due to the down-regulation of melanin-related proteins and HPA axis genes. The melanogenesis of B16F10 cells was inhibited by the conditioned medium of HaCaT cells treated with SP.

CONCLUSIONS

Overall, these results indicate that excess SP originated from mental stress interferes with melanogenesis through keratinocytes in the skin. The HPA axis is the key downstream to perceive the SP signaling and furtherly regulate the melanogenesis.

Plant-Derived Compounds as Promising Therapeutics for Vitiligo

Vitiligo is the most common depigmenting disorder characterized by white patches in the skin. The pathogenetic origin of vitiligo revolves around autoimmune destruction of melanocytes in which, for instance, oxidative stress is responsible for melanocyte molecular, organelle dysfunction and melanocyte specific antigen exposure as well as melanocyte cell death and thus serves as an important contributor for vitiligo progression. In recent years, natural products have shown a wide range of pharmacological bioactivities against many skin diseases, and this review focuses on the effects and mechanisms of natural compounds against vitiligo models. It is showed that some natural compounds such as flavonoids, phenols, glycosides and coumarins have a protective role in melanocytes and thereby arrest the depigmentation, and, additionally, Nrf2/HO-1, MAPK, JAK/STAT, cAMP/PKA, and Wnt/β-catenin signaling pathways were reported to be implicated in these protective effects. This review discusses the great potential of plant derived natural products as anti-vitiligo agents, as well as the future directions to explore.

Evaluating the Sun Protection Factor of Cosmetic Formulations Containing Afzelin

Exposure to UV radiation damages the skin and increases the risk of skin cancer. Sunscreen is used to protect the skin from the harmful effects of UV radiation. However, the chemical UV filters used in sunscreen can show toxicity and cause allergic reactions. A safe sunscreen that includes a lower content of chemical UV filters and exerts an excellent effect on UV protection needs to be developed. The objective of this study was to investigate whether the addition of afzelin to sunscreen could improve the sun protection factor (SPF). A synergistic effect between afzelin and organic sunscreen agents including padimate O and oxybenzone was confirmed. Interestingly, 100% in vitro SPF-boosting was observed when afzelin (0.05%) was applied with a standard SPF formulation containing organic sunscreens while afzelin alone had no contribution to the SPF. In vivo SPF analysis of the standard SPF formulation showed an SPF value of 13.3 that increased to 20.1 when supplemented with afzelin (0.05%). Additionally, afzelin showed no skin irritation in a human trial. These results suggest that afzelin is useful as a natural additive in sunscreen formulations and provides an SPF-boosting effect. Afzelin supplementation to the formulation showed the potential to reduce the use of synthetic photoprotectors, which could minimize the risk of synthetic agent toxicity.

Morin Induces Melanogenesis via Activation of MAPK Signaling Pathways in B16F10 Mouse Melanoma Cells

Morin is a well-known flavonoid, and has been reported to have various properties, such as anti-cell death, antioxidant, and anti-inflammatory properties. Although studies on the biochemical and biological actions of morin have been reported, the melanin biosynthesis effects and molecular mechanisms are unknown. In this study, we first found that morin has the effect of enhancing melanin biosynthesis in B16F10 mouse melanoma cells, and analyzed the molecular mechanism. In this study, we examined the effects of morin on the melanin contents and tyrosinase activity, as well as the protein expression levels of the melanogenic enzymes TRP-1, TRP-2, and microphtalmia-associated transcription factor (MITF) in B16F10 mouse melanoma cells. Morin showed no cytotoxicity in the concentration range of 5–100 μM, and significantly increased the intracellular tyrosinase activity and melanin contents. In mechanism analysis, morin increased the protein expression of TRP-1, TRP-2, and MITF associated with melanogenesis. Furthermore, morin increased phosphorylated ERK and p38 at the early time, and decreased phosphorylated ERK after 12 h. The results suggest that morin enhances melanin synthesis through the MAPK signaling pathways in B16F10 mouse melanoma cells.

Syntenin regulates melanogenesis via the p38 MAPK pathway

Melanogenesis is the synthesis of the skin pigment melanin, which serves a critical role in the study of pigmentary skin diseases. Syntenin has been identified as a melanosome protein, but its role in melanogenesis is not completely understood. The present study aimed to investigate the effects and mechanisms underlying syntenin on melanogenesis in immortalized human melanocytes. Depletion of syntenin expression increased both tyrosinase (Tyr) activity and melanin content. Syntenin silencing also increased the protein expression levels of Tyr, pre‑melanosomal protein and microphthalmia‑associated transcription factor. In addition, the results indicated that syntenin regulated melanogenesis by upregulating the phosphorylation of p38 mitogen‑activated protein kinase (p38 MAPK). Taken together, these findings suggested that the regulation of melanogenesis by syntenin may be mediated by the activation of p38 MAPK and that syntenin might provide new insights into the pathogenesis of pigmented diseases.

Melanogenic Effects of Maclurin Are Mediated through the Activation of cAMP/PKA/CREB and p38 MAPK/CREB Signaling Pathways

Melanogenesis is the biological process which the skin pigment melanin is synthesized to protect the skin against ultraviolet irradiation and other external stresses. Abnormal biology of melanocytes is closely associated with depigmented skin disorders such as vitiligo. In this study, we examined the effects of maclurin on melanogenesis and cytoprotection. Maclurin enhanced cellular tyrosinase activity as well as cellular melanin levels. We found that maclurin treatment increased the expression of microphthalmia-associated transcription factor (MITF), tyrosinase-related protein- (TRP-) 1, TRP-2, and tyrosinase. Mechanistically, maclurin promoted melanogenesis through cyclic adenosine monophosphate (cAMP) response element binding (CREB) protein-dependent upregulation of MITF. CREB activation was found to be mediated by p38 mitogen-activated protein kinase (MAPK) or cAMP-protein kinase A (PKA) signaling. In addition, maclurin-induced CREB phosphorylation was mediated through the activation of both the cAMP/PKA and the p38 MAPK signaling pathways. Maclurin-induced suppression of p44/42 MAPK activation also contributed to its melanogenic activity. Furthermore, maclurin showed protective effects against H₂O₂ treatment and UVB irradiation in human melanocytes. These findings indicate that the melanogenic effects of maclurin depend on increased MITF gene expression, which is mediated by the activation of both p38 MAPK/CREB and cAMP/PKA/CREB signaling. Our results thus suggest that maclurin could be useful as a protective agent against hypopigmented skin disorders.

Afzelin suppresses proinflammatory responses in particulate matter-exposed human keratinocytes

Particulate matter (PM), a widespread airborne contaminant, is a complex mixture of solid and liquid particles suspended in the air. Recent studies have demonstrated that PM induces oxidative stress and inflammatory reactions, and may cause certain skin diseases. Afzelin is a flavonoid isolated from Thesium chinense Turcz, which has anti‑inflammatory, anticancer and antibacterial properties. Therefore, the present study aimed to investigate if afzelin affected inflammatory responses in human keratinocytes exposed to PM. HaCaT cells were treated with PM (25 µg/cm2) in the presence or absence of afzelin (200 µM). Here, standard reference material 1649b was used as PM. Cell viability was assessed using the water‑soluble tetrazolium salt‑1 assay. The generation of reactive oxygen species (ROS) was measured using the dichloro‑dihydro‑​fluorescein diacetate assay. Gene and protein expression were investigated using reverse transcription‑quantitative polymerase chain reaction and western blot analysis, respectively. Levels of secreted inflammatory cytokines were measured using ELISA. The results suggested that afzelin inhibited PM‑induced proinflammatory cytokine mRNA expression and protein secretion in HaCaT cells. In addition, afzelin suppressed PM‑induced intracellular ROS generation, and p38 mitogen‑activated protein kinase and transcription factor activator protein‑1 component c‑Fos and c‑Jun activation. The results indicated that afzelin exerts anti‑inflammatory and antioxidant effects in PM‑exposed HaCaT. Afzelin may have potential for preventing PM‑induced inflammatory skin diseases.

The different roles of 5-HT1A/2A receptors in fluoxetine ameliorated pigmentation of C57BL/6 mouse skin in response to stress

BACKGROUND

5-HT1A receptor was participated in fluoxetine induced melanogenesis in melanocytes and in normal C57BL/6 mice, but we know little about whether other 5-HT receptors are involved in regulation of fluoxetine promotes pigmentation.

OBJECTIVE

To investigate the role of 5-HT receptors in regulation of fluoxetine ameliorates chronic unpredictable mild stress (CUMS) and chronic restraint stress (CRS) induce hypopigmentation in C57BL/6 mice.

METHODS

CUMS and CRS were used to induce depigmentation in mice and evaluate the effect of fluoxetine. Western blot, immunohistochemistry and Q-PCR assay were used to determine the levels of protein and mRNA. Masson Fontana staining was used for melanin staining and FITC-Phalloidin staining was used to detect the expression of F-actin. Zebrafish and B16F10 cells were used for the mechanism research.

RESULTS

Fluoxetine (2.6 mg/kg, ig) ameliorated hypopigmentation induced by CUMS and CRS in mice, significantly increased the mRNA and protein levels of 5-HT1 A and 5-HT2 A receptors in mice and B16F10 cells. The effect of fluoxetine on melanogenesis in B16F10 cells and zebrafish were inhibited by WAY100635 (a selective 5-HT1 A receptor antagonist) and ketanserin (a 5-HT2 A receptor antagonist), respectively. Activation of p38 MAPK signaling pathways was contributed to fluoxetine induced melanogenesis and inhibited by WAY100635, but not ketanserin. However, ketanserin selectively weakened the action of fluoxetine promoted migration and up-regulated Rab27a protein expression in B16F10 cells.

CONCLUSIONS

5-HT1 A and 2 A receptors contribute to melanogenesis and migration property of fluoxetine. The newly revealed mechanism indicates that fluoxetine and its analogues may be a potential drug for treatment of depigmentation disorders.

Effects of volatile oil from ginger on the murine B16 melanoma cells and its mechanism

In this study, the inhibitory effects of volatile oil from ginger on melanogenesis and its antioxidant characteristics were investigated. The effects of volatile oil from ginger on cell proliferation, melanin content and tyrosinase activity were determined using a microplate reader. In addition, the expression of melanogenesis-related protein was determined by western blotting. The results indicate that the tested concentrates of volatile oil from ginger showed inhibitory effects on cell proliferation and melanogenesis. This revealed that volatile oil from ginger exhibited apparent capacities for scavenging ROS and lipid peroxidation. Furthermore, volatile oil from ginger improved the activities of GSH, SOD and CAT in B16 melanoma cells. These results demonstrated that volatile oil from ginger suppressed melanin synthesis through its antioxidant properties and the inhibitory effects on tyrosinase activity and melanogensis-related proteins. Hence, volatile oil from ginger could be used as an effective skin-whitening agent applied in food industry.

Compounds isolated from Eriobotrya deflexa leaves protect against ultraviolet radiation B-induced photoaging in human fibroblasts

Ultraviolet (UV) irradiation leads to skin photoaging because of the upregulation of matrix metalloproteinase (MMP)-1 and downregulation of type I collagen and tissue inhibitor of metalloproteinase (TIMP)-1. Eriobotrya deflexa (Hemsl.) Nakai (Rosaceae) is a flowering plant endemic to Taiwan, and its leaves have been used as an expectorant and in antitussive folk remedy. Our previous studies have demonstrated that an E. deflexa leaf extract functions as a free radical scavenger. The current evaluated the antiphotoaging effect of partitioned fractions and specific compounds from the leaves of E. deflexa by using bioguided isolation, compound identification, and biological activity testing with UVB-irradiated human fibroblasts (WS-1 cells). E. deflexa leaves were extracted with 95% ethanol and then partitioned using a sequential treatment of n-hexane, ethyl acetate, and n-butanol (n-BuOH). The bioactive n-BuOH fraction was used for isolation and purification through chromatography. The compounds were identified by analyzing their physical and spectroscopic properties. We identified eight compounds from this fraction; of these compounds, 3-O-α-l-rhamnopyranosyl-(1‴→6″)-β-d-galactopyranoside (1), hyperin (2), afzelin (5), and cryptochlorogenic acid methyl ester (7) were isolated from E. deflexa for the first time, and they exhibited MMP-1 inhibition activity. The IC₅₀ values were 96.5, 89.5, 93.4, and 92.8μM for 1, 2, 5, and 7, respectively. These compounds also enhanced the expression of procollagen type I, and TIMP-1 and hyperin (2) were found to be most effective with IC₅₀ values of 56.7 and 70.3μM, respectively. Hyperin (2) could reduce intracellular reactive oxygen species production in UVB-irradiated WS-1 cells, with the corresponding IC₅₀ value being 80.7μM. Liquid chromatography triple-quadrupole mass spectrometry was used for the quantitative and chemical fingerprint analysis of active compounds. Quercetin 3-O-α-l-rhamnopyranosyl-(1‴→6″)-β-d-galactopyranoside (1), hyperin (2), afzelin (5), and cryptochlorogenic acid methyl ester (7) constituted 24.2±3.9, 5.5±1.0, 3.4±0.3, and 67.1±8.1mg/g of dry weight in the active n-BuOH fraction, respectively. Our results demonstrate that the extract and the isolated active compounds from E. deflexa leaves possess the potential for protection against skin photoaging.