Oxyresveratrol and trans-dihydromorin from the twigs of Cudrania tricuspidata as hypopigmenting agents against melanogenesis

An Outlook on Platinum-Based Active Ingredients for Dermatologic and Skincare Applications

Platinum-based materials exhibit a broad spectrum of biological activities, including antioxidant, anti-inflammatory, antimicrobial, and pro-collagen synthesis properties, making them particularly useful for various biomedical applications. This review summarizes the biological effects and therapeutic potential of platinum-based active ingredients in dermatological and skincare applications. We discuss their synthesis methods and their antioxidant, anti-inflammatory, antimicrobial, and collagen synthesis properties, which play essential roles in treating skin conditions including psoriasis and acne, as well as enhancing skin aesthetics in anti-aging products. Safety and sustainability concerns, including the need for green synthesis and comprehensive toxicological assessments to ensure safe topical applications, are also discussed. By providing an up-to-date overview of current research, we aim to highlight both the potential and the current challenges of platinum-based active ingredients in advancing dermatology and skincare solutions.

Comparative transcriptome analysis reveals growth and molecular pathway of body color regulation in turbot (Scophthalmus maximus) exposed to different light spectrum

Fish body color changes play vital roles in adapting to ecological light environment and influencing market value. However, the initial mechanisms governing the changes remain unknown. Here, we scrutinized the impact of light spectrum on turbot (Scophthalmus maximus) body coloration, exposing them to red, blue, and full light spectra from embryo to 90 days post hatch. Transcriptome and quantitative real-time PCR (qRT-PCR) analyses were employed to elucidate underlying biological processes. The results showed that red light induced dimorphism in turbot juvenile skin pigmentation: some exhibited black coloration (Red_Black_Surface, R_B_S), while others displayed lighter skin (Red_White_Bottom, R_W_B), with red light leading to reduced skin lightness (L*) and body weight, particularly in R_B_S group. Transcriptomic and qRT-PCR analyses showcased upregulated gene expressions related to melanin synthesis in R_B_S individuals, notably tyrosinase (tyr), tyrosinase-related protein 1 (tyrp1), and dopachrome tautomerase (dct), alongside solute carrier family 24 member 5 (slc24a5) and oculocutaneous albinism type II (oca2) as pivotal regulators. Nervous system emerged as a critical mediator in spectral environment-driven color regulation. N-methyl d-aspartate (NMDA) glutamate receptor, and calcium signaling pathway emerged as pivotal links intertwining spectral conditions, neural signal transduction, and color regulation. The individual differences in NMDA glutamate receptor expression and subsequent neural excitability seemed responsible for dichromatic body coloration in red light-expose juveniles. This study provides new insights into the comprehending of fish adaptation to environment and methods for fish body color regulation and could potentially help enhance the economic benefit of fish farming industry.

Silver Carp (Hypophthalmichthys molitrix) Scale Collagen Peptides-1 (SCPs1) Inhibit Melanogenesis through Downregulation of the cAMP-CREB Signaling Pathway

The mechanism of silver carp scale collagen peptides (SCPs1) on melanogenesis and its mechanism of action were examined in mouse melanoma cells (B16). The cell viability and effects of SCPs1 on intracellular tyrosinase (TYR) activity and melanin, reactive oxygen species (ROS), glutathione (GSH) and cyclic adenosine monophosphate (cAMP) content were examined. The regulatory mechanism of SCPs1 on the cAMP response element-binding protein (CREB) signaling pathway was analyzed. The cell viability of the SCPs1 group was >80% (0.01-1 mg/mL) and the inhibitory rate of SCPs1 on B16 cell melanin increased in a dose-dependent manner. The highest inhibitory rate of SCPs1 on melanin content reaching 80.24%. SCPs1 significantly increased the GSH content and decreased the tyrosinase activity, as well as the content of ROS and cAMP. Western blot analysis showed that SCPs1 significantly inhibited melanocortin-1 receptor (MC1R) expression and CREB phosphorylation in the cAMP-CREB signaling pathway, leading to downregulation of microphthalmia-associated transcription factor (MITF) and the expression of TYR, TYR-related protein-1 (TRP-1) and TRP-2. SCPs1 also inhibited the expression of MC1R, MITF, TYR, TRP-1 and TRP-2 at the transcriptional level. Taken together, SCPs1 inhibited melanin synthesis through the downregulation of the cAMP-CREB signaling pathway. Fish-derived collagen peptides could potentially be applied in skin whitening products.

Potential application of natural bioactive compounds as skin-whitening agents: A review

BACKGROUND

Melanin is a skin pigment that gives color to the skin, hair, and eyes. The accumulation or over production of melanin can lead to aesthetic problems as well as serious diseases associated with hyperpigmentation. Skin lightening is described as the procedure of using natural or synthetic products to lighten the skin tone or provide an even skin complexion by reducing the amount of melanin in the skin; therefore, skin lightening products help people to treat their skin problems. Ingredients such as hydroquinone, ascorbic acid, and retinoic acid were used as whitening agents to lighten the skin. However, they have many adverse effects on the skin and body health, such as skin irritation.

AIM

In this review, firstly, discuss on the directly/indirectly target melanogenesis-related signal pathways. Secondly, summarize potential natural bioactive ingredients with skin lightening properties from plants, marine organisms, microorganisms. Finally, the remaining problems and future challenges are also discussed.

METHODS

For relevant literature, a literature search was conducted using Google Scholar and Web of Science. Natural bioactive compounds, tyrosinase inhibitors, and other related topics were researched and evaluated.

RESULTS

Natural products isolated from plant and animal resources are potential active cosmetic candidates for lightening the skin tone and skin whitening and protection against UV irradiation. Natural bioactive ingredients as cosmetic whitening additives have attracted increasingly attention due to their safety and cost effectiveness, with few side effects.

CONCLUSION

Although natural active substances have been advocated for use in whitening cosmetics in recent years, there are still many challenges due to the fact that traditional inhibitors are used perennial in cosmetics which cannot be easily changed and the research on natural active substances is still in its infancy. In the future, by improving the extraction technique of natural extracts, it is achieved to give a qualitative and quantitative analysis of the active ingredients of the extracts, to determine the effect of the active components of action, and to find the substances that have the best possible whitening effect in natural organisms.

Synergistic inhibitory effects of the oxyresveratrol and dacarbazine combination against melanoma cells

Various therapies have been developed to target malignant melanoma, which is associated with a high mortality rate worldwide. Although dacarbazine (DTIC) is employed for treating melanoma, it is associated with several side effects. Hence, patients with melanoma are co-treated with additional drugs to mitigate the side effects of DTIC. In the present study, synergistic therapeutic effects of the DTIC/oxyresveratrol (ORT) combination were examined using the human malignant melanoma WM-266-4 cell line. Treatment with ORT and DTIC inhibited the proliferation of WM-266-4 cells. Compared with those in the ORT- and DTIC-treated groups, the proportion of cells arrested at the S phase, as well as apoptotic rates, were increased in the ORT and DTIC co-treatment group. In WM-266-4 cells, synergistic proliferation-inhibitory activities of the ORT/DTIC combination were assessed based on cell viability and migration, antioxidant capacity, cytokine production, cell cycle arrest, apoptotic rate and protein expression through WST-1 assay, wound healing assay, flow cytometry and western blotting. Furthermore, the expression levels of proteins, including NOTCH, involved in the pathogenesis of solid cancers, such as melanoma, were examined. Overall, the ORT/DTIC combination synergistically promoted cell cycle arrest at the S phase and the apoptosis of WM-266-4 cells. Thus, this combination treatment may serve as a novel therapeutic strategy for treating malignant melanoma.

Oxyresveratrol: Sources, Productions, Biological Activities, Pharmacokinetics, and Delivery Systems

Oxyresveratrol has recently attracted much research attention due to its simple chemical structure and diverse therapeutic potentials. Previous reviews describe the chemistry and biological activities of this phytoalexin, but additional coverage and greater accessibility are still needed. The current review provides a more comprehensive summary, covering research from 1955 to the present year. Oxyresveratrol occurs in both gymnosperms and angiosperms. However, it has never been reported in plants in the subclass Sympetalae, and this point might be of both chemotaxonomic and biosynthetic importance. Oxyresveratrol can be easily obtained from plant materials by conventional methods, and several systems for both qualitative and quantitative analysis of oxyresveratrol contents in plant materials and plant products are available. Oxyresveratrol possesses diverse biological and pharmacological activities such as the inhibition of tyrosinase and melanogenesis, antioxidant and anti-inflammatory activities, and protective effects against neurological disorders and digestive ailments. However, the unfavorable pharmacokinetic properties of oxyresveratrol, including low water solubility and poor oral availability and stability, have posed challenges to its development as a useful therapeutic agent. Recently, several delivery systems have emerged, with promising outcomes that may improve chances for the clinical study of oxyresveratrol.

(E)-1-(Furan-2-yl)-(substituted phenyl)prop-2-en-1-one Derivatives as Tyrosinase Inhibitors and Melanogenesis Inhibition: An In Vitro and In Silico Study

A series of (E)-1-(furan-2-yl)prop-2-en-1-one derivatives (compounds 1–8) were synthesized and evaluated for their mushroom tyrosinase inhibitory activity. Among these series, compound 8 (2,4-dihydroxy group bearing benzylidene) showed potent tyrosinase inhibitory activity, with respective IC₅₀ values of 0.0433 µM and 0.28 µM for the monophenolase and diphenolase as substrates in comparison to kojic acid as standard compound 19.97 µM and 33.47 µM. Moreover, the enzyme kinetics of compound 8 were determined to be of the mixed inhibition type and inhibition constant (K_i) values of 0.012 µM and 0.165 µM using the Lineweaver-Burk plot. Molecular docking results indicated that compound 8 can bind to the catalytic and allosteric sites 1 and 2 of tyrosinase to inhibit enzyme activity. The computational molecular dynamics analysis further revealed that compound 8 interacted with two residues in the tyrosinase active site pocket, such as ASN260 and MET280. In addition, compound 8 attenuated melanin synthesis and cellular tyrosinase activity, simulated by α-melanocyte-stimulating hormone and 1-methyl-3-isobutylxanthine. Compound 8 also decreased tyrosinase expressions in B16F10 cells. Based on in vitro and computational studies, we propose that compound 8 might be a worthy candidate for the development of an antipigmentation agent.

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

The efficacy of oily components is often difficult to evaluate due to their incompatibility with most models. Here, we emulsified adlay bran oil (ABO), processed it to a nanoscale, and investigated its anti-hyperpigmentation efficacy, assessed for its inhibitory effects against tyrosinase activity and melanin production, in an in vitro system (mouse melanoma B16F10 cells) and an in vivo system (zebrafish embryos). ABO induced dose-dependent reductions in tyrosinase activity and melanin production in both the melanoma cells and zebrafish, without affecting viability. The efficacy of ABO was strongly influenced by emulsion particle size in the zebrafish but not in the cells. These results indicate that ABO has potential as a tyrosinase inhibitor and anti-hyperpigmentation agent and that the emulsion system is an effective method for delivering the bioactive components of ABO to living systems that could be utilized for other oily components.

Toxic trans-crotonaldehyde in mitochondria intercepted by oxyresveratrol contributing to anticancer

The aim of this study was to explore how the toxic trans-crotonaldehyde (TCA) in mitochondria or aldehyde dehydrogenase (ALDH) at different pHs was intercepted by oxyresveratrol (Oxy-Res) contributing to anticancer. Ultraviolet-visible (UV-vis) spectroscopy and Raman spectroscopy were employed. UV-vis spectra showed that the Oxy-Res red shifted the peak of the toxic TCA from 316 nm to 325 nm, while the peaks of the Oxy-Res shifted from 329 nm with 290 nm and 300 nm to 325 nm with 303 nm. In the mitochondria, the Oxy-Res blue shifted the peaks of the toxic TCA from 325 nm with 303 nm to 321 nm with 301 nm. Raman spectra revealed that the Oxy-Res caused shifting of the CHO of the toxic TCA from 1,689 cm^-1 to 1,671 cm^-1 with band decline. The CC of the toxic TCA at 1641 cm^-1 was split into 1,639 cm^-1 and 1,642 cm^-1 with band decline. The bands of the Oxy-Res at 1634 cm^-1 , 1,617 cm^-1 , and 1,595 cm^-1 disappeared. In the mitochondria, the CC of the toxic TCA at 1641 cm^-1 splitting disappeared. In ALDH, with the decrease of pH from 7.8 to 6.5, the CHO of the toxic TCA did not red shift from 1,689 cm^-1 to 1,674 cm^-1 up to pH 6.5. There was no change in the CC of the toxic TCA at 1640 cm^-1 in ALDH at different pHs. The conclusion of the study was that the CHO of the toxic TCA was intercepted by the Oxy-Res under the action of ALDH in the mitochondria, particularly at pH 7.8. © 2019 IUBMB Life, 2019.

Tyrosinase-based TLC Autography for anti-melanogenic drug screening

Tyrosinase-based TLC (thin layer chromatography) was developed for screening of anti-melanogenic drugs. In particular, this technique enables researchers to identify melanogenic inhibitor(s) in tested mixtures with the naked eye. In comparison with traditional colorimetric screening assays for tyrosinase inhibitor(s), not only is tyrosinase-based TLC a more cost-effective option (nearly one-tenth the enzyme cost of colorimetric methods) but also is a more sensitive detection approach for kojic acid (KA), a standard anti-melanogenic drug. The detection limit of tyrosinase-based TLC and colorimetric tyrosinase assay for KA was 0.0125 and 1.25 μg, respectively, demonstrating that the former was 100-fold more sensitive than the latter to determine the tyrosinase inhibitory rate of KA. Furthermore, the results of this method have demonstrated excellent precision by Gage Repeatability and Reproducibility (Gage R&R), with the variation of total Gage R&R being 28.24%. To verify the applicability of tyrosinase-based TLC, this platform was employed to screen melanogenic inhibitor(s) from Ganoderma formosanum extracts and two of all fractions (GFE-EA F4, F5) obtained showed depigmenting activity. It is noteworthy that these two fractions also exerted anti-melanogenesis activity on zebrafish, therefore verifying the credibility of tyrosinase-based TLC. In sum, this technique provides new insight into the discovery of novel melanogenic inhibitor(s).

Antioxidant and Anti-tyrosinase Activities of Phenolic Extracts from Rape Bee Pollen and Inhibitory Melanogenesis by cAMP/MITF/TYR Pathway in B16 Mouse Melanoma Cells

Rape bee pollen possesses many nutritional and therapeutic properties because of its abundant nutrimental and bioactive components. In this study, free (FPE) and bound (BPE) phenolic extracts of rape bee pollen were obtained, phenolic and flavonoid contents were determined, and composition of phenolic acids was analyzed. In vitro antioxidant and anti-tyrosinase (TYR) activities of FPE and BPE were compared, and inhibitory melanogenesis of FPE was further evaluated. Results showed FPE and BPE contain total phenolic contents of 11.76 and 0.81 mg gallic acid equivalents/g dry weight (DW) and total flavonoid contents of 19.24 and 3.65 mg rutin equivalents/g DW, respectively. Phenolic profiling showed FPE and BPE fractions contained 12 and 9 phenolic acids, respectively. FPE contained the highest rutin content of 774.87 μg/g. FPE and BPE showed the high antioxidant properties in vitro and high inhibitory activities for mushroom TYR. Higher activities of FPE than those of BPE can be attributed to difference in their phenolic compositions. Inhibitory melanogenesis activities of FPE against B16 were further evaluated. Results showed suppressed intracellular TYR activity, reduced melanin content, and promoted glutathione synthesis (p < 0.05) in FPE-treated cells. FPE reduced mRNA expression of TYR, TYR-related protein (TRP)-1 and TRP-2, and significantly suppressed cyclic adenosine monophosphate (cAMP) levels through down-regulation of melanocortin 1 receptor gene expression (p < 0.05). FPE reduced mRNA expression of microphthalmia-associated transcription factor (MITF), significantly inhibiting intracellular melanin synthesis (p < 0.05). Hence, FPE regulates melanogenesis of B16 cells involved in cAMP/MITF/TYR pathway. These results revealed that FPE can be used as pharmaceutical agents and cosmetics to protect cells from abnormal melanogenesis.

The depigmenting effect of natural resorcinol type polyphenols Kuwanon O and Sanggenon T from the roots of morus australis

ETHNOPHARMACOLOGICAL RELEVANCE

Morus australis, one of the major Morus species growing in East Asia, is rich in phenolic compounds. The extract of M. australis has been used as skin whitening components for a long period. The action mechanisms of its principal constituents are still unclear. This study aims to evaluate the skin lightening effects of phenolic compounds extracted from the root of M. australis in different melanocyte systems and artificial skin models.

MATERIALS AND METHODS

The depigmenting effect of resorcinol type polyphenols (RTPs) from the root extract of M. australis was evaluated in murine b16 and melan-a cell lines using a combined sulforhodamine B assay. Tyrosinase activity and the expression of melanogenesis proteins were evaluated for the mechanism study. The artificial skin model is used as a replacement of the animal test.

RESULTS

Only Kuwanon O and Sanggenon T were found to have significant depigmenting effects in both murine b16 and melan-a cell lines. Their depigmenting mechanisms are slightly different in the two cell systems. In b16 cells, Kuwanon O and Sanggenon T, together with the other two RTPs, induced post-transcriptional degradations of MITF without suppressing its mRNA expression, leading to significant decreases of TRP-1 and TRP-2 production. While in melan-a cells, the levels of tyrosinase families were suppressed via MITF downregulation at both transcription and translation level by RTPs, with Kuwanon O inducing the greatest suppression. Further evaluations in artificial skin model demonstrated the outstanding depigmenting effects of Kuwanon O and Sanggenon T.

CONCLUSIONS

Kuwanon O and Sanggenon T from M.australis root extract are two potential skin whitening ingredients. To screen resorcinol flavonone derivatives with an isoprenyl group in the Diels-Alder substituent might be an option for the search of potent hypopigmenting agents from plants.

Cudrania tricuspidata: an updated review on ethnomedicine, phytochemistry and pharmacology

This review summarized the botany, traditional uses, phytochemistry and pharmacology ofCudrania tricuspidata, and the limitations of the studies on this species were also discussed so as to serve as the basis for further research and development of this medicinal plant.

Extract of Ganoderma formosanum Mycelium as a Highly Potent Tyrosinase Inhibitor

In this study, the inhibitory effect of Ganoderma formosanum mycelium extracts on tyrosinase, the central regulatory enzyme being responsible for cutaneous pigmentation, was investigated in both cell-free and cellular enzymatic systems, as well as in phenotype-based zebrafish model. Bioassay-guided purification indicated that the ethyl acetate fraction of G. fromosanum mycelium ethanolic extract (GFE-EA) demonstrated the highest inhibition toward cell-free tyrosinase (IC50 = 118.26 ± 13.34 ppm). The secreted and intracellular melanin of B16-F10 cells were reduced by GFE-EA through suppression of tyrosinase activity (IC50 = 102.27 ± 9.49 ppm) and its protein expression. Moreover, GFE-EA decreased surface pigmentation level of zebrafish via down-regulation of tyrosinase activity. Most of all, there is no significant difference in morphology and mortality between control and GFE-EA treated groups. Not only does GFE-EA exhibit similar depigmenting efficacy to kojic acid with lower dosage (approximately one-seventh of dose), but show less toxicity to zebrafish. It is worth noting that GFE-EA is extracted from mycelium, which subverts the general concept that mycelium lacks certain bioactivities possessed by fruit bodies. Altogether, it would appear that GFE-EA has great potential for application in the cosmetics industry.