Tyrosinase Levels Research Articles

A fluorescence biosensor for tyrosinase activity analysis based on silicon-doped carbon quantum dots.

Tyrosinase (TYR) plays a pivotal role in the biosynthesis of melanin, and its activity level holds critical implications for vitiligo, melanoma cancer, and food nutritional value. The sensitive determination of TYR activity is of great significance for both fundamental research and clinical investigations. In this work, we successfully synthesized silicon-doped carbon quantum dots (Si-CQDs) through a one-pot hydrothermal method with trans-aconitic acid as carbon source and N-[3-(Trimethoxysilyl)propyl]ethylenediamine as the dopant, exhibiting remarkable fluorescence quantum yield (QY) and photostability. Correspondingly, Si-CQDs were used as a probe to construct a sensitive, rapid, and user-friendly fluorescence method for TYR detection. The method relied on the oxidation of isoprenaline (ISO) by TYR, where Si-CQDs were employed as a highly efficient probe. The testing mechanism was the internal filtering effect (IFE) observed between Si-CQDs and the oxidative system of ISO and TYR. Under the optimized conditions, the fluorescence strategy exhibited a detection range of 0.05-2.0 U/mL for TYR with a limit of detection (LOD) of 0.041 U/mL. Furthermore, we successful demonstrated the accurate determination of TYR levels in human serum, showcasing the promising potential of this method in various practical scenarios.

Profiling of tyrosinase levels, antioxidant and DNA protective properties in different edible and medicinal mushroom species from India

AbstractBackgroundTyrosinase is a polyphenol oxidase, one of the globally attracted enzymes for its multi‐mechanistic approaches in various fields such as pharma, food, environment, medicine, and agriculture. Tyrosinase from natural nutritive edible mushrooms gained more attention for their rich levels and inexpensive nature. Our previous work has revealed that mushroom tyrosinase has strong similarities in structure and function with that of skin tyrosinase, which has significance as a skin tumor marker. Besides, mushrooms are a richer source of antioxidants. However, it is imperative to analyze all the available varieties of mushrooms for bioactive potentials like tyrosinase and antioxidant levels. Thus, the main goal of the study was to identify the variety of mushrooms that can be selected for continuous multiplication and propagation as a viable source for tyrosinase, which can be employed to screen tyrosinase inhibitors as skin tumor inhibitors.ResultsOf the 18 varieties screened for tyrosinase levels, Boletus edulis, Termitomyces hemii, and Termitomyces mummiformis had high levels of tyrosinase and exhibited potent hydrogen peroxide and nitric oxide scavenging activity as well as DNA protection. The potent DNA and antioxidant abilities appear to be due to the enriched levels of hydroxybenzoates.ConclusionThe current study could provide an economic source of tyrosinase (mushrooms) that can be used to monitor tyrosinase inhibitors, a potent component that enables their use against skin cancer.

In Vitro Study of the Effects of Five Chemically Modified Tetracycline (CMT) Analogs on Human Epidermal Melanogenesis: Potential as Novel Anti-Melanogenic Agents

Treatment of hyperpigmented skin disorders by novel drug candidates without side effects remains an ongoing area of research. Chemically modified tetracyclines (CMTs) are a group of nonantimicrobial tetracycline drugs that have been shown to possess multiple pharmacological activities. We have previously documented the anti-melanogenic effects of CMT-3 and its 9-amino derivative, CMT-308. Herein, we have extended our analysis to evaluate other CMT analogs, namely CMT-1, CMT-4, CMT-5, CMT-6, and CMT-8, for their impact on melanogenesis using primary human epidermal melanocytes (HEMn-DP cells). CMT analogs were screened using a tetrazolium-based assay to identify nontoxic concentration ranges that were further used to analyze the effects of CMTs on cellular melanin content and morphology (via quantitation of dendricity). Cellular tyrosinase (TYR) activity and levels of melanogenesis proteins, TYR, and microphthalmia transcription factor (MITF) were also evaluated to elucidate the mechanisms underlying their effects on melanogenesis. The findings demonstrated that exposure to CMT-8 resulted in notable cytotoxic effects at concentrations >10 µM; hence, all five analogs were further evaluated and compared at 10 µM. None of the five CMT analogs exhibited any impact on intracellular melanin in HEMn-DP cells at the concentration of 10 µM. However, CMT-1, CMT-4, and CMT-8 robustly suppressed dendricity parameters in HEMn-DP cells, while CMT-5 and CMT-6 showed no effect, suggesting that only a subset of CMT analogs can attenuate melanocyte dendricity. Moreover, the analog CMT-5, which has β-diketone blocked, was ineffective, thus confirming the role of this moiety in suppressing dendrite formation. CMT-1 and CMT-8 did not affect cellular tyrosinase activity, while CMT-4 suppressed TYR activity at 10 µM. The capacity of CMT-4 and CMT-8 to suppress dendricity was partly associated with their ability to downregulate MITF protein levels, while CMT-1 had no effect on MITF but suppressed TYR protein levels. The results of this study indicate that CMT-1, CMT-4, and CMT-8 merit further investigation using in vivo studies as potential drug candidates for the treatment of hyperpigmentation disorders.

In Situ Tyrosinase Monitoring by Wearable Microneedle Patch toward Clinical Melanoma Screening.

Despite the potential indicating role of tyrosinase (TYR) in cutaneous melanoma, how to capture the real changes of TYR in suspicious skin remains a major challenge. Unlike the traditional human serum test, this study reports a sensing platform that incorporates a wearable microneedle (MN) patch and trimetallic Au@Ag-Pt nanoparticles (NPs) for surface-enhanced Raman scattering (SERS) and colorimetric dual-mode detecting TYR in human skin in situ toward potential melanoma screening. In the presence of TYR, catechol immobilized on MN is preferentially oxidized to benzoquinone, which competitively impedes the interaction of MN and Au@Ag-Pt NPs, triggering the SERS-colorimetric signal reciprocal switch. Using a B16F10 mouse melanoma model, our platform is capable of noninvasively piercing the skin surface and detecting TYR levels before and during anti-PD-1 antibody treatment, which would be highly informative for prognostic judgment and illness monitoring of melanoma. Through in situ sensing for capturing the metabolic changes of TYR in advance, this platform was successfully applied to discriminate the melanoma subjects from skin moles and normal ones (p < 0.001), as well as screen potential melanoma from lactate dehydrogenase (LDH)-negative patients. Melanoma growth and prognosis can still be monitored through recording the continuous change of TYR levels. More importantly, the well-defined flexible and stretchable characteristics of the MN patch allow robustly adhering to the skin without inducing chemical or physical irritation. We believe this platform integrating MN-based in situ sensing, TYR responsiveness, and SERS/colorimetric dual-readout strategy will have high clinical importance in early diagnosis and monitoring of cutaneous melanoma.

Antimelanogenic potential of brewer's spent grain extract through modulation of the MAPK/MITF axis

Beer brewing produces >39 million tons of brewer's spent grain (BSG) per year worldwide. Although BSG is rich in protein, fiber, and phytochemicals, it is mainly used as livestock feed, and some is discarded. In this study, we attempted to assess the antimelanogenesis effects of BSG and identify the functional components. To this end, we investigated the antioxidant and antimelanin synthesis effects of a BSG extract (BSGE). The results showed that BSGE has high DPPH radical-scavenging activity and inhibited α-MSH-induced melanin synthesis in B16F10 cells cultured in both 2D and 3D environments. BSGE also reduced the expression levels of MITF, TRP-1, TRP-2, and tyrosinase in B16F10 cells by regulating the MAPK pathway. We confirmed the skin-whitening effect of BSGE in 3D reconstituted human skin and zebrafish embryo models. HPLC analysis showed that BSGE contains ferulic acid and p-coumaric acid, which are known to have whitening effects. Thus, BSGE can be used in multifunctional cosmetics as a sustainable ingredient with antioxidant and skin-whitening properties.

Effectively synthesized functional Si-doped carbon dots with the applications in tyrosinase detection and lysosomal imaging

There has been significant interest in the preparation and versatile applications of carbon dots (CDs) due to their immense potential value in sensors and imaging. In this work, silicon-doped green carbon dots (Si-CDs) with high quantum yield and rich epoxypropyl were effectively synthesized. Given the clinical diagnostic importance of abnormal levels of tyrosinase (TYR), sensitive detection of TYR is significant for clinical research. A fluorescence signal-off strategy with Si-CDs as probe was constructed to determine TYR based on the oxidation of dopamine by TYR. The detection ranges of this method were 0.01–1.5 and 10–30 U/mL with the detection limit of 0.0046 U/mL, the lower limit of quantification (LLOQ) was 0.01 U/mL, and TYR was successfully and accurately monitored in human serum. Additionally, due to the role of lysosomes in cellular regulatory processes, including TYR levels and fluorescence stability characteristics of Si-CDs in acidic conditions, it was envisaged to use Si-CDs as probe to establish real-time monitoring of lysosomes. According to fluorescence colocation analysis, Si-CDs had intrinsic lysosomal targeting ability to HepG2 and L-02 (with Pearson correlation coefficients were 0.90 and 0.91, respectively). The targeting of Si-CDs to lysosomes was due to the acidophilic effect of the epoxypropyl on its surface.

Maltol has anti-cancer effects via modulating PD-L1 signaling pathway in B16F10 cells.

Introduction: Among skin cancers, melanoma has a high mortality rate. Recent advances in immunotherapy, particularly through immune checkpoint modulation, have improved the clinical treatment of melanoma. Maltol has various bioactivities, including anti-oxidant and anti-inflammatory properties, but the anti-melanoma property of maltol remains underexplored. The aim of this work is to explore the anti-melanoma potential of maltol through regulating immune checkpoints. Methods: The immune checkpoint PD-L1 was analyzed using qPCR, immunoblots, and immunofluorescence. Melanoma sensitivity towards T cells was investigated via cytotoxicity, cell viability, and IL-2 assays employing CTLL-2 cells. Results: Maltol was found to reduce melanin contents, tyrosinase activity, and expression levels of tyrosinase and tyrosinase-related protein 1. Additionally, maltol suppressed the proliferative capacity of B16F10 and induced cell cycle arrest. Maltol increased apoptotic rates by elevating cleaved caspase-3 and PARP. The co-treatment with maltol and cisplatin revealed a synergistic effect on inhibiting growth and promoting apoptosis. Maltol suppressed IFN-γ-induced PD-L1 and cisplatin-upregulated PD-L1 by attenuating STAT1 phosphorylation, thereby enhancing cisplatin's cytotoxicity against B16F10. Maltol augmented sensitivity to CTLL-2 cell-regulated melanoma destruction, leading to an increase in IL-2 production. Discussion: These findings demonstrate that maltol restricts melanoma growth through the downregulation of PD-L1 and elicits T cell-mediated anti-cancer responses, overcoming PD-L1-mediated immunotherapy resistance of cisplatin. Therefore, maltol can be considered as an effective therapeutic agent against melanoma.

Inhibitory effect of Cyrtomium falcatum on melanogenesis in α-MSH-stimulated B16F10 murine melanoma cells

Objective: To explore the anti-melanogenic potential of Cyrtomium falcatum. Methods: The effects of Cyrtomium falcatum crude extract and its solvent fractions on tyrosinase activity, melanin content, and the expressions of melanogenesis-related genes and proteins were analyzed in α-melanocyte-stimulating hormone (α-MSH)-stimulated B16F10 cells. Results: α-MSH treatment significantly increased tyrosinase activity, and extracellular and intracellular melanin content, as well as the expression levels of tyrosinase, microphthalmia-associated transcription factor (MITF), tyrosinase-related protein (TRP)-1, and TRP-2 in B16F10 cells. Treatment with Cyrtomium falcatum crude extract and its solvent fractions reduced tyrosinase activity and extracellular and intracellular melanin content and downregulated the expression levels of tyrosinase, MITF, TRP-1, and TRP-2 in a dose-dependent manner. Conclusions: Cyrtomium falcatum has potential anti-melanogenesis effects and can be used as a potential source material in cosmeceutical industry for the research and development of novel lead molecules with whitening properties.

Sargassum fusiforme Extract Induces Melanogenesis through the cAMP/PKA/CREB Signaling Pathway

The aim of this study was to investigate the effect of Sargassum fusiforme extract (SFE) on melanogenesis and its mechanism both in vitro and ex vivo. The melanogenic-inducing effect of SFE was evaluated using a melanin contents assay and a cellular tyrosinase activity assay. To investigate whether SFE could protect melanocytes against oxidative stress, hydrogen peroxidase was used. The molecular mechanism underlying the effect of SFE on melanogenesis was determined via Western blot analysis of tyrosinase, a microphthalmia-associated transcription factor (MITF), and a phosphorylated cAMP response element-binding protein (p-CREB) expression. The degree of pigmentation in a 3D skin model was determined by measuring the L* values. Contents of melanin in ex vivo human hair follicles were evaluated via Fontana–Masson staining. SFE significantly increased melanin contents and cellular tyrosinase activity in human epidermal melanocytes. SFE also increased the phosphorylation of CREB and the protein levels of tyrosinase and MITF. Moreover, SFE attenuated oxidative stress-induced cytotoxicity and depigmentation. Finally, the melanogenesis promoting effect of SFE was confirmed in both a 3D skin model and ex vivo human hair follicles. These findings suggest that SFE can induce melanogenesis via the cAMP/PKA/CREB signaling pathway in human epidermal melanocytes through its hyperpigmentation activity.

Inhibitory Effects of Polyphenol- and Flavonoid-Enriched Rice Seed Extract on Melanogenesis in Melan-a Cells via MAPK Signaling-Mediated MITF Downregulation.

Melanin production is an important process that prevents the host skin from harmful ultraviolet radiation; however, an overproduction of melanin results in skin diseases. In the present study, we determined the antioxidative and anti-melanogenic activities of polyphenol- and flavonoid-enriched rice seed extracts in melan-a cells. The polyphenol and flavonoid content of Hopum (HP) and Sebok (SB) rice seed extracts was measured. The antioxidant capacity was determined using the ABTS radical scavenging method. SB contained high amounts of polyphenols and flavonoids, which significantly increased antioxidative activity compared with HP. Various concentrations of these extracts were evaluated in a cytotoxicity using melan-a cells. At 100 µg/mL, there was no significant difference for all treatments compared with untreated cells. Therefore, 100 µg/mL was selected as a concentration for the further experiments. SB significantly suppressed the phosphorylation/activation of p-38 MAPK, increased the expression of phosphorylated ERK 1/2 and Akt, and downregulated the microphthalmia-associated transcription factor (MITF). This resulted in decreased levels of tyrosinase and tyrosinase-related protein-1 and -2. These results indicate the potential of polyphenol- and flavonoid-enriched rice seed as a treatment for hyperpigmentation.

Phenolic acids in Panax ginseng inhibit melanin production through bidirectional regulation of melanin synthase transcription via different signaling pathways

BackgroundOur previous investigation indicated that the preparation of Panax ginseng Meyer (P. ginseng) inhibited melanogenesis. It comprised salicylic acid (SA), protocatechuic acid (PA), p-coumaric acid (p-CA), vanillic acid (VA), and caffeic acid (CA). In this investigation, the regulatory effects of P. ginseng phenolic acid monomers on melanin production were assessed. MethodsIn vitro and in vivo impact of phenolic acid monomers were assessed. ResultsSA, PA, p-CA and VA inhibited tyrosinase (TYR) to reduce melanin production, whereas CA had the opposite effects. SA, PA, p-CA and VA significantly downregulated the melanocortin 1 receptor (MC1R), cycle AMP (cAMP), protein kinase A (PKA), cycle AMP-response element-binding protein (CREB), microphthalmia-associated transcription factor (MITF) pathway, reducing mRNA and protein levels of TYR, tyrosinase-related protein 1 (TYRP1), and TYRP2. Moreover, CA treatment enhanced the cAMP, PKA, and CREB pathways to promote MITF mRNA level and phosphorylation. It also alleviated MITF protein level in α-MSH-stimulated B16F10 cells, comparable to untreated B16F10, increasing the expression of phosphorylation glycogen synthase kinase 3β (p-GSK3β), β-catenin, p-ERK/ERK, and p-p38/p38. Furthermore, the GSK3β inhibitor promoted p-GSK3β and p-MITF expression, as observed in CA-treated cells. Moreover, p38 and ERK inhibitors inhibited CA-stimulated p-p38/p38, p-ERK/ERK, and p-MITF increase, which had negative binding energies with MC1R, as depicted by molecular docking. ConclusionP. ginseng roots' phenolic acid monomers can safely inhibit melanin production by bidirectionally regulating melanin synthase transcription. Furthermore, they reduced MITF expression via MC1R/cAMP/PKA signaling pathway and enhanced MITF post-translational modification via Wnt/mitogen-activated protein kinase signaling pathway.

Debut of a novel AIE-based fluorescent probe as tyrosinase tracer to image skin pigmentary disorders

Tyrosinase (TYR) functions as the critical enzyme in biosynthesis of melanin, and its abnormality is an important hallmark for skin pigmentary disorders. This renders the visualization of tyrosinase dynamics a strategically vital way to facilitate clinical diagnostic and monitoring. However, the use of small molecule fluorescent probes to assess tyrosinase levels and evaluate related therapeutics and drugs has been limited. This is mainly due to the aggregation-induced quenching (ACQ) effects of existing fluorescent probes. In this study, we introduce the first aggregation-induced emission (AIE) small molecule fluorescent probe, BTFTYR, for simple, highly sensitive, and effective detection of tyrosinase activity. The specific fluorescence signal generated by tyrosinase catalytic reaction enables the imaging of pigment cells. We demonstrate its application in visualizing tyrosinase with high contrast in living vertebrates, benefiting from the inherent photobleaching resistance of AIE materials, large Stokes shift, and considerable tissue permeability. We also show the outstanding skin penetration capability of BTFTYR in a skin model. Moreover, we present the first comprehensive evaluation of relevant clinical therapeutic approaches or drugs, including ultraviolet B (UVB) irradiation, kojic acid, and α-MSH, by interpreting the tyrosinase variation with BTFTYR. Finally, our studies confirm that BTFTYR neither causes skin inflammation nor produces visceral toxicity, making it a promising chemical tool for medical diagnosis and drug screening. This tool may further help elucidate the pathomechanisms associated with tyrosinase.

Hydrolyzed Conchiolin Protein (HCP) Extracted from Pearls Antagonizes both ET-1 and α-MSH for Skin Whitening.

Pearl powder is a famous traditional Chinese medicine that has a long history in treating palpitations, insomnia, convulsions, epilepsy, ulcers, and skin lightining. Recently, several studies have demonstrated the effects of pearl extracts on protection of ultraviolet A (UVA) induced irritation on human skin fibroblasts and inhibition of melanin genesis on B16F10 mouse melanoma cells. To further explore the effect we focused on the whitening efficacy of pearl hydrolyzed conchiolin protein (HCP) on human melanoma MNT-1 cells under the irritation of alpha-melanocyte-stimulating hormone (α-MSH) or endothelin 1 (ET-1) to evaluate the intracellular tyrosinase and melanin contents, as well as the expression levels of tyrosinase (TYR), tyrosinase related protein 1 (TRP-1), and dopachrome tautomerase (DCT) genes and related proteins. We found that HCP could decrease the intracellular melanin content by reducing the activity of intracellular tyrosinase and inhibiting the expression of TYR, TRP-1, DCT genes and proteins. At the same time, the effect of HCP on melanosome transfer effect was also investigated in the co-culture system of immortalized human keratinocyte HaCaT cells with MNT-1. The result indicated that HCP could promote the transfer of melanosomes in MNT-1 melanocytes to HaCaT cells, which might accelerate the skin whitening process by quickly transferring and metabolizing melanosomes during keratinocyte differentiation. Further study is needed to explore the mechanism of melanosome transfer with depigmentation.

Laser-assisted drug delivery of synthetic alpha melanocyte stimulating hormone and L-tyrosine leads to increased pigmentation area and expression of melanogenesis genes in a porcine hypertrophic scar model.

One symptom of hypertrophic scar (HTS) that can develop after burn injury is dyschromia with hyper- and hypopigmentation. There are limited treatments for these conditions. Previously, we showed there is no expression of alpha melanocyte stimulating hormone (α-MSH) in hypopigmented scars, and if these melanocytes are treated with synthetic α-MSH in vitro, they respond by repigmenting. The current study tested the same hypothesis in the in vivo environment using laser-assisted drug delivery (LADD). HTSs were created in red Duroc pigs. At Day 77 (pre), they were treated with CO2 fractional ablative laser (FLSR). Synthetic α-MSH was delivered as a topical solution dissolved in l-tyrosine (n = 6, treated). Control scars received LADD of l-tyrosine only (n = 2, control). Scars were treated and examined weekly through Week 4. Digital images and punch biopsies of hyper, hypo-, and normally pigmented scar and skin were collected. Digital pictures were analyzed with ImageJ by tracing the area of hyperpigmentation. Epidermal sheets were obtained from punch biopsies through dispase separation and RNA was isolated. qRT-PCR was run for melanogenesis-related genes: tyrosinase (TYR), tyrosinase-related protein-1 (TYRP1), and dopachrome tautomerase (DCT). Two-way ANOVA with multiple comparisons and Dunnett's correction compared the groups. The areas of hyperpigmentation were variable before treatment. Therefore, data is represented as fold-change where each scar was normalized to its own pre value. Within the LADD of NDP α-MSH + l-tyrosine group, hyperpigmented areas gradually increased each week, reaching 1.3-fold over pre by Week 4. At each timepoint, area of hyperpigmentation was greater in the treated versus the control (1.04 ± 0.05 vs. 0.89 ± 0.08, 1.21 ± 0.07 vs. 0.98 ± 0.24, 1.21 ± 0.08 vs. 1.04 ± 0.11, 1.28 ± 0.11 vs. 0.94 ± 0.25; fold-change from pre-). Within the treatment group, pretreatment, levels of TYR were decreased -17.76 ± 4.52 below the level of normal skin in hypopigmented scars. After 1 treatment, potentially due to laser fractionation, the levels decreased to -43.49 ± 5.52. After 2, 3, and 4 treatments, there was ever increasing levels of TYR to almost the level of normally pigmented skin (-35.74 ± 15.72, -23.25 ± 6.80, -5.52 ± 2.22 [p < 0.01, Week 4]). This pattern was also observed for TYRP1 (pre = -12.94 ± 1.82, Week 1 = -48.85 ± 13.25 [p < 0.01], Weeks 2, 3, and 4 = -34.45 ± 14.64, -28.19 ± 4.98, -6.93 ± 3.05 [p < 0.01, Week 4]) and DCT (pre = -214.95 ± 89.42, Week 1 = -487.93 ± 126.32 [p < 0.05], Weeks 2, 3, and 4 = -219.06 ± 79.33, -72.91 ± 20.45 [p < 0.001], -76.00 ± 24.26 [p < 0.001]). Similar patterns were observed for scars treated with LADD of l-tyrosine alone without NDP α-MSH. For each gene, in hyperpigmented scar, levels increased at Week 4 of treatment compared to Week 1 (p < 0.01). A clinically-relevant FLSR treatment method can be combined with topical delivery of synthetic α-MSH andl-tyrosine to increase the area of pigmentation and expression of melanogenesis genes in hypopigmented HTS. LADD of l-tyrosine alone leads to increased expression of melanogenesis genes. Future studies will aim to optimize drug delivery, timing, and dosing.

Inhibitory Effects of Caulerpa racemosa, Ulva intestinalis, and Lobophora challengeriae on Tyrosinase Activity and α-MSH-Induced Melanogenesis in B16F10 Melanoma Cells.

Melanogenesis involves a synthesis of melanin pigment and is regulated by tyrosinase. The addition of whitening agents with tyrosinase-inhibiting properties in cosmetics is becoming increasingly important. In this study, the ethanolic extracts from twelve seaweeds were assessed for tyrosinase-inhibiting activity using mushroom tyrosinase and melanin synthesis in B16F10 melanoma cells. The highest mushroom tyrosinase inhibition (IC50) was observed with Lobophora challengeriae (0.15 ± 0.01 mg mL-1); treatment was more effective than kojic acid (IC50 = 0.35 ± 0.05 mg mL-1), a well-known tyrosinase inhibitor. Three seaweeds, Caulerpa racemosa, Ulva intestinalis, and L. challengeriae, were further investigated for their ability to reduce melanogenesis in B16F10 cells. The ethanolic extracts of C. racemosa, U. intestinalis, and L. challengeriae showed inhibitory effects by reducing melanin and intracellular tyrosinase levels in B16F10 cells treated with α-melanocyte stimulating hormone in a dose-dependent manner. C. racemosa (33.71%) and L. challengeriae (36.14%) at 25 µg mL-1 reduced melanin production comparable to that of kojic acid (36.18%). L. challengeriae showed a stronger inhibition of intracellular tyrosinase (decreased from 165.23% to 46.30%) than kojic acid (to 72.50%). Thus, ethanolic extracts from C. racemosa, U. intestinalis, and L. challengeriae can be good sources of natural tyrosinase inhibitors and therapeutic or cosmetic agents in the future.

Fermented Aronia melanocarpa Inhibits Melanogenesis through Dual Mechanisms of the PI3K/AKT/GSK-3β and PKA/CREB Pathways.

UV light causes excessive oxidative stress and abnormal melanin synthesis, which results in skin hyperpigmentation disorders such as freckles, sunspots, and age spots. Much research has been carried out to discover natural plants for ameliorating these disorders. Aronia melanocarpa contains various polyphenolic compounds with antioxidative activities, but its effects on melanogenesis have not been fully elucidated. In this study, we investigated the inhibitory effect of fermented Aronia melanocarpa (FA) fermented with Monascus purpureus on melanogenesis and its underlying mechanism in the B16F10 melanoma cell line. Our results indicate that FA inhibited tyrosinase activity and melanogenesis in alpha-melanocyte-stimulating hormone (α-MSH)-induced B16F10 cells. FA significantly downregulated the PKA/CREB pathway, resulting in decreased protein levels of tyrosinase, TRP-1, and MITF. FA also inhibited the transcription of MITF by increasing the phosphorylation levels of both GSK3β and AKT. Interestingly, we demonstrated that these results were owing to the significant increase in gallic acid, a phenolic compound of Aronia melanocarpa produced after the fermentation of Monascus purpureus. Taken together, our research suggests that Aronia melanocarpa fermented with Monascus purpureus acts as a melanin inhibitor and can be used as a potential cosmetic or therapeutic for improving hyperpigmentation disorders.

A novel C6-sulfonated celastrol analog as a tyrosinase and melanin inhibitor: Design, synthesis, biological evaluation and molecular simulation

To improve the application prospects of celastrol (CE), a novel C6-sulfonated CE analog (called CENFN in this study) was designed via quantum chemical calculations. On this basis, CENFN was synthesized and clarified by spectroscopic methods (IR, 1H NMR, UV–Vis and fluorescence spectra). Subsequently, the tyrosinase and melanin inhibitory effects of CE and CENFN were comparably explored in silico and in vitro. The calculation and spectroscopy results confirmed the rationality of the synthetic reactions of CENFN. The molecular simulation results showed that CENFN possessed a higher level of tyrosinase and melanin inhibition than CE, which was consistent with the experimental results. All these findings can help to design and synthesize CE analogs as tyrosinase and melanin inhibitors.

New ICT-Based Ratiometric Two-Photon near Infrared Probe for Imaging Tyrosinase in Living Cells, Tissues, and Whole Organisms

Melanoma is a type of highly malignant and metastatic skin cancer. In situ molecular imaging of endogenous levels of the melanoma biomarker tyrosinase (TYR) may decrease the likelihood of mortality. In this study, we proposed the weakly fluorescent probe 1-(4-(2-(4-(dicyanomethylene)-4H-chromen-2-yl)vinyl)phenyl)-3-(4-hydroxybenzyl)urea (DCM-HBU), which releases a strong red-shifted fluorescent signal after a TYR-mediated oxidation followed by hydrolysis of the urea linkage. The large Stokes shift of the dye is owed to the recovery of the intramolecular charge transfer (ICT) effect. The resulting probe derivate shows a highly ratiometric fluorescence output. Furthermore, the simultaneous excitation by two near-infrared (NIR) photons of the released derivative of dicyanomethylene-4H-pyran (DCM-NH2) fluorophore could avoid the usual drawbacks, such as cellular absorption, autofluorescence, and light scattering, due to an usually short wavelength of the excitation light on biological systems, resulting in images with deeper tissue penetration. In addition, the probe is useful for the quantitative sensing of TYR activity in vivo, as demonstrated in zebrafish larvae. This new ratiometric two-photon NIR fluorescent probe is expected to be useful for the accurate detection of TYR in complex biosystems at greater depths than other one-photon excited fluorescent probes.

Biochemical Pilot Study on Effects of Pomegranate Seed Oil Extract and Cosmetic Cream on Neurologically Mediated Skin Inflammation in Animals and Humans: A Comparative Observational Study.

The presence of phenobarbital and formaldehyde in drugs, food, and beverages can lead to various health issues, including inflammation, oncogenesis, and neurological distress. Psychological stress leads to mood fluctuations and the onset of skin inflammation. Skin inflammation has a range of causes, including chemicals, heavy metals, infection, immune-related disorders, genetics, and stress. The various treatments for skin inflammation include medical and cosmetic creams, diet changes, and herbal therapy. In this study, we investigated the effects of Avocom-M and pomegranate seed oil extract (PSOE) against phenobarbital- and formaldehyde-induced skin biochemical changes in rats. We analyzed the constituents of PSOE using gas chromatography-mass spectrometry and inductively coupled plasma-mass spectrometry. We also observed biochemical changes in the skin of human volunteers with and without TROSYD and PSOE as a skin cream. We compared the biochemical changes in human volunteers' skin before treatment and 21 days after the treatment stopped. The outcomes showed an improvement in the rats' biochemical status, due to PSOE and Avocom-M treatment. The human volunteers treated with TROSYD and PSOE showed substantial amelioration of skin inflammation. PSOE, Avocom-M, and TROSYD produced beneficial effects by reducing the levels of cyclooxygenase-2, lipid peroxidation, tyrosinase, hyaluronidase, elastase, collagenase, and nitric oxide in the animals tested on and in human volunteers.

Wamena Arabica Coffee (Coffea Arabica) Bean Extract Cream Inhibits The Increase Of Tyrosynase And Melanin Levels In Guinea Pig (Cavia Porcellus) Exposed To UVB Lights

Introduction: Most of the aging process in the skin occurs due to exposure to sunlight, especially UV-B light, resulting in an increase in the activity of the tyrosinase enzyme and the amount of melanin which will cause hyperpigmentation of the skin. Antioxidants are substances that can provide protection from endogenous and exogenous oxidative stress by free radicals. The purpose of this study was to prove that Wamena roasted Arabica coffee bean extract cream can inhibit the enzymes tyrosinase and melanin in guinea pig exposed to UV-B lights. Methods: The design of this study was an animal experimental design with a randomized post-test only control group. The subjects of the study were 30 guinea pigs divided into 3 groups: group 1 as control, group 2 with placebo cream and group 3 was with 3% Wamena arabica coffee bean extract cream. The group 2 and 3 were exposed to UV-B light for 2 weeks. The skin of the guinea pig was excised for examination of the levels of the enzymes tyrosinase and melanin. Result: The average tyrosinase and melanin levels in control group were 19.891% and 4.62%, treatment group 2 was an average of 42.699% and 9.26% and treatment group 3 was 23.886% and 4.87%. Conclusion: Arabica coffee (Coffea arabica) bean extract cream roasted Wamena 3% inhibits the tyrosinase enzyme levels and inhibits the melanin in guinea pigs (Cavia porcellus) which are exposed to ultraviolet B light.