Salicylic acid in ginseng root alleviates skin hyperpigmentation disorders by inhibiting melanogenesis and melanosome transport

Glycyrrhiza glabra extract as a skin-whitening Agent: Identification of active components and CRTC1/MITF pathway-inhibition mechanism

ETHNOPHARMACOLOGICAL RELEVANCE

Glycyrrhiza glabra. L is a traditional herbal medicine widely recognized for its skin-whitening properties; however, the specific active compounds and underlying molecular mechanisms responsible for these effects remain largely uncharacterized.

AIM OF THE STUDY

To identify the bioactive constituents in G. glabra extract (GGE) responsible for its depigmenting effects and to elucidate the molecular mechanisms underlying their skin-whitening activity.

METHODS

The depigmenting activity of GGE was assessed through NaOH lysis, DOPA oxidation assays, and high-performance liquid chromatography for component identification. Network pharmacology, western blotting, immunohistochemistry, and immunofluorescence were performed to investigate the effects of glabridin on pigmentation-related targets.

RESULTS

Among the tested extracts, the 80 % ethanol extract of G. glabra (GGE80) exhibited the most potent inhibition of mushroom tyrosinase (TYR) activity in vitro, along with significantly reduced melanin content and TYR activity in B16F10 melanoma cells. GGE80 also suppressed melanin accumulation and downregulated the key melanogenesis-associated proteins. Seven major compounds were identified in GGE80: liquiritin, isoliquiritin, liquiritigenin, isoliquiritigenin, glycyrrhizic acid, 18β-glycyrrhetinic acid, and glabridin. Among these, liquiritin, isoliquiritigenin and glabridin were identified as the primary melanin-inhibitory agents. Of these, glabridin demonstrated the most potent, activity in both in vivo and in vitro models. Network pharmacology analysis revealed that glabridin targeted MITF, a central transcription factor regulating melanogenic enzymes. Mechanistic studies further indicated that glabridin reduced CREB phosphorylation and SOX10 protein expression, both critical regulators of MITF transcription. Additionally, glabridin inhibited the nuclear translocation of CRTC1, a CREB-regulated transcription coactivator, leading to its cytoplasmic retention and phosphorylation.

CONCLUSIONS

The GGE80 demonstrated the most significant whitening effects. Among its constituents, glabridin was identified as the key active compound responsible for inhibiting melanogenesis. Mechanistically, glabridin exerts its effects by suppressing CREB/CRTC1-mediated transcriptional activation of MITF.

Phenolics as Active Ingredients in Skincare Products: A Myth or Reality?

Phenolic compounds, with their diverse biological activities, are widely explored as cosmetic ingredients with photoprotective, antioxidant, anti-inflammatory, and anti-hyperpigmentation properties, offering a multitargeted approach to combat photo-induced skin aging. The study analyzed 1299 cosmetic products from 2021 to 2024 to understand the market impact of phenolic compounds and their mechanism of action against photo-induced skin damage. A total of 28 active phenolic compounds were identified and the prevalence of phenolics was 13.2% in anti-aging products, 5.2% in sunscreens and 4.8% in aftersun products. Bakuchiol and polyphenols, such as resveratrol, chrysin, and hesperidin methyl chalcone, were found in anti-aging products. Sunscreens and aftersun products were counted with ferulic and caffeic acids, and salicylic acid, respectively. Antioxidant activity was found to be the primary mechanism of action of phenolic compounds by scavenging reactive species, thus mitigating oxidative stress. Ferulic and caffeic acids, chrysin, and glucosylrutin can also absorb UV radiation, acting preventively against solar-induced skin damage. This study provides insights into the limited use of phenolic compounds in commercial cosmetics, despite their diverse biological activities, and suggests potential barriers to wider use in skin and sun care products.

Current and Future Outlook of Research on Renewable Cosmetics Derived From Biomass

The use of biomass in cosmetics is a growing trend, driven by an increasing demand for sustainable and environmentally friendly products. Biomass, derived from a range of renewable resources, offers numerous benefits for skincare due to its natural properties. This review highlights recent research advancements, current applications, and future prospects of biomass-based cosmetics. While these products are gaining popularity for their eco-friendly nature, the industry faces several challenges. One key issue is ensuring the sustainability of biomass sourcing, as overharvesting could lead to environmental degradation. In addition, the lack of standard regulations and certifications for biomass-based products poses a challenge to consumer confidence and product transparency. Despite these promising developments, safety and toxicity considerations must be addressed, particularly regarding the long-term use of natural substances in cosmetics. Notably, a comparative examination of plant-, wood-, and waste-sourced biomass is provided by this review, spotlighting novel extraction and formulation strategies that balance efficacy with environmental stewardship, an approach that distinguishes it from prior reviews focused on single-source biomass. By linking fundamental research findings to emerging standards, the review offers fresh insights into how sustainability, regulatory measures, and consumer trust can jointly shape a more robust future for eco-conscious beauty solutions.

Potassium 4-Methoxysalicylate (4MSK) Exerts a Skin Lightening Effect by Acting on Melanocytes and Keratinocytes

BACKGROUND

Hyperpigmentation is a common acquired disorder that can be a cosmetic concern for many individuals. To reduce and prevent hyperpigmentation, numerous skin lightening agents have been developed. Potassium 4-methoxysalicylate (4MSK) is a skin lightening agent that was approved as an active skin lightening ingredient of quasi-drugs by the Ministry of Health, Labour and Welfare of Japan in 2003. For over 20 years, 4MSK has been widely used in quasi-drug and cosmetic products. However, the mechanism of action and efficacy of 4MSK on skin pigmentation and skin lightness have not been publicly reported.

AIMS

This study aimed to assess the mechanism of action and the efficacy of 4MSK on facial pigmentation.

METHODS

The mechanism of action of 4MSK on epidermal cells was investigated using human melanocytes, human keratinocytes, and human 3D epidermal equivalents. The efficacy of 4MSK on facial pigmentation was evaluated by a human clinical study, which is a double-blind, split-face, placebo-controlled, paired-design study.

RESULTS

4MSK significantly suppressed melanin content in cultured human melanocytes and a 3D epidermal equivalent. It also promoted gene expression of differentiation markers of human keratinocytes. In the clinical study, a 4MSK formulation significantly increased skin lightness values in both pigmented and non-pigmented areas of cheek skin. In addition, it reduced the desquamation area ratio of the cheek.

CONCLUSIONS

4MSK reduces skin pigmentation and contributes to brighter skin by acting on both melanocytes and keratinocytes.

Supramolecular Salicylic Acid Alleviates Skin Photoaging by Increasing Collagen Density and Elasticity

BACKGROUND

Skin rejuvenation has always been of great concern. Although salicylic acid (SA) has multiple properties, it is mainly used in dermatology as a superficial peeling agent that can improve photodamaged epidermis. However, the effect of SA on the photoaging dermis is unclear.

PURPOSE

To evaluate the efficacy and safety of supramolecular SA alone for treating photoaged skin, and the effect of SSA on photoaged dermis.

METHODS

This is a double-blind, randomized, placebo-controlled trial. 36 patients with photodamaged hands were enrolled. One hand was randomly selected as SSA treated side. 30% SSA biweekly and 2% SSA daily was applied for 4 months; an additional follow-up was performed 2 weeks after the last treatment. Skin photoaging score (SPS), global aesthetic improvement scale (GAIS), viscoelasticity, ultrasound parameters, color and transepidermal water loss (TEWL) were assessed.

RESULTS

SSA treatment induced a significant increase in collagen density and skin elasticity, accompanied by an increase in dermal thickness and a decrease in melanin index and TEWL. As result, the GAIS and the SPS were improved significantly after SSA treatment. No adverse events were observed after SSA treatments, and 98% of the subjects were satisfied or very satisfied with the treatment.

CONCLUSION

SSA can increase collagen density and skin elasticity to alleviate skin photoaging effectively and safely.

LEVEL OF EVIDENCE I

This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Molecular mechanisms underlying Tao-Hong-Si-Wu decoction treating hyperpigmentation based on network pharmacology, Mendelian randomization analysis, and experimental verification

CONTEXT

Hyperpigmentation, a common skin condition marked by excessive melanin production, currently has limited effective treatment options.

OBJECTIVE

This study explores the effects of Tao-Hong-Si-Wu decoction (THSWD) on hyperpigmentation and to elucidate the underlying mechanisms.

MATERIALS AND METHODS

We employed network pharmacology, Mendelian randomization, and molecular docking to identify THSWD's hub targets and mechanisms against hyperpigmentation. The Cell Counting Kit-8 (CCK-8) assay determined suitable THSWD treatment concentrations for PIG1 cells. These cells were exposed to graded concentrations of THSWD-containing serum (2.5%, 5%, 10%, 15%, 20%, 30%, 40%, and 50%) and treated with α-MSH (100 nM) to induce an in vitro hyperpigmentation model. Assessments included melanin content, tyrosinase activity, and Western blotting.

RESULTS

ALB, IL6, and MAPK3 emerged as primary targets, while quercetin, apigenin, and luteolin were the core active ingredients. The CCK-8 assay indicated that concentrations between 2.5% and 20% were suitable for PIG1 cells, with a 50% cytotoxicity concentration (CC50) of 32.14%. THSWD treatment significantly reduced melanin content and tyrosinase activity in α-MSH-induced PIG1 cells, along with downregulating MC1R and MITF expression. THSWD increased ALB and p-MAPK3/MAPK3 levels and decreased IL6 expression in the model cells.

DISCUSSION AND CONCLUSION

THSWD mitigates hyperpigmentation by targeting ALB, IL6, and MAPK3. This study paves the way for clinical applications of THSWD as a novel treatment for hyperpigmentation and offers new targeted therapeutic strategies.

Phytochemical Investigation and Biological Activities of Desmodium heterocarpon Extract as Anti-Tyrosinase: Isolation of Natural Compounds, In Vitro and In Silico Study

Tyrosinase is an important enzyme in the biosynthesis of melanin. Many skin-whitening agents that inhibit tyrosinase activity from natural sources have been identified because they are harmless and non-toxic. In this work, 114 samples of 54 Fabaceae plants were assessed for their anti-tyrosinase activity using a dopachrome method. The results found that Desmodium heterocarpon stems and roots demonstrated the highest tyrosinase inhibitory activity at 20 µg/mL (92.50 ± 1.09%), whereas the water extract of Artocarpus lacucha and kojic acid demonstrated 87.41 ± 0.61% and 95.71 ± 0.33%, respectively. Six compounds were isolated from this plant, including genistein (1); hexadecanoic acid (2); salicylic acid (3); β-sitosterol-D-glucoside (4); 2,3-dihydroxybenzoic acid (5); and 2,5-dihydroxybenzoic acid (6). Among them, 2,5-dihydroxybenzoic acid demonstrated a potential effect for tyrosinase inhibition with an IC50 of 57.38 µg/mL, while standards of kojic acid and the water extract of A. lacucha showed 2.46 and 0.15 µg/mL, respectively. 2,3-dihydroxybenzoic acid had a similar structure as 2,5-dihydroxybenzoic acid; however, it was shown to have tyrosinase inhibitory activity, with an IC50 of 128.89 µg/mL. Studies using computer simulations confirmed this reservation. The determination of antimicrobial activities found that 2,5-dihydroxybenzoic acid showed the strongest inhibitory activity against Staphylococcus aureus, with MIC and MBC of 5 and 5 µg/mL, respectively. In addition, it inhibited MRSA, S. epidermidis, Propionibacterium acnes, Escherichia coli, and Pseudomonas aeruginosa, with MIC and MBC of 15-30 and 15-40 µg/mL. It showed potential activities against yeast and filamentous fungi, such as Candida albicans, Microsporum gypseum, Trichophyton rubrum, and T. mentagrophytes, with MIC and MFC of 15 µg/mL. So, 2,5-dihydroxybenzoic acid could inhibit tyrosinase activity and microorganisms that cause skin diseases. Therefore, it can be concluded that this plant has advantageous properties that will be investigated and further developed for possible uses, particularly in the cosmetic and pharmaceutical industries.

Discovery of superior bioactive peptides of two edible Lentinus mushrooms protein hydrolysate in biological activities: tyrosinase inhibitory and antioxidant activity

This study investigated protein hydrolysates obtained from Lentinus squarrosulus and Lentinus edodes fruiting bodies via gastric protease hydrolysis and ultrafiltration, yielding peptides with a molecular weight below 6.5 kDa. These hydrolysates displayed significant tyrosinase inhibitory activity similar to positive controls, peptide from Chinese quince seed (RHAKF) and kojic acid. L. squarrosulus-derived hydrolysates exhibited superior antioxidant properties compared to L. edodes in DPPH (47% vs. 23%) and ABTS (77% vs. 23%) assays. Identified bioactive peptides, particularly LILGGSSS from L. squarrosulus, interacted with tyrosinase through hydrogen bonds at specific residues. Notably, these protein hydrolysates showcased potent tyrosinase inhibition without cytotoxic effects, presenting promising prospects for addressing hyperpigmentation caused by excessive tyrosinase activity from stress or UV exposure.

The Characteristics and Biological Activities of Niosome-Entrapped Salicylic Acid-Contained Oleoresin from Dipterocarpus alatus for Skin Product Applications

Salicylic acid (SA) is widely renowned for its efficacy as a beneficial ingredient for skincare, especially for acne and uneven skin texture. The salicylic acid (SA) niosome formulation combined with the essential component of oleoresin from Dipterocarpus alatus Roxb. ex G. Don or Yang-Na (ODA) was developed and investigated for its physical characteristics, biological effects, and stability. The findings demonstrated that SA combined with ODA in the niosome formulation F4 enhanced the entrapment efficiency of SA, as well as the physical properties and stability of the formulation. Furthermore, the release pattern of this combined formulation indicated sustained release of SA. The permeation of SA was higher in the presence of ODA compared to SA-niosome formulations without ODA. Moreover, this F4 could downregulate the secretion of iNOS, COX-2, and TNF-α including anti-Propionibacterium acnes activities. Consequently, the incorporation of ODA into the niosome formulation has the potential to improve the entrapment efficiency of SA, facilitating controlled release and enhancing permeation, nitric oxide inhibition capabilities, and anti-P. acnes activity. Therefore, F4 has the potential to be developed as a topical product for the combined treatment of inflammation and P. acnes-associated conditions in the future.

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.

Mechanism, Formulation, and Efficacy Evaluation of Natural Products for Skin Pigmentation Treatment

Skin pigmentation typically arises from the excessive secretion and accumulation of melanin, resulting in a darker complexion compared to normal skin. Currently, the local application of chemical drugs is a first-line strategy for pigmentation disorders, but the safety and efficacy of drugs still cannot meet clinical treatment needs. For long-term and safe medication, researchers have paid attention to natural products with higher biocompatibility. This article begins by examining the pathogenesis and treatment approaches of skin pigmentation diseases and summarizes the research progress and mechanism of natural products with lightening or whitening effects that are clinically common or experimentally proven. Moreover, we outline the novel formulations of natural products in treating pigmentation disorders, including liposomes, nanoparticles, microemulsions, microneedles, and tocosomes. Finally, the pharmacodynamic evaluation methods in the study of pigmentation disorder were first systematically analyzed. In brief, this review aims to collect natural products for skin pigmentation treatment and investigate their formulation design and efficacy evaluation to provide insights for the development of new products for this complex skin disease.

Molecular understanding of the therapeutic potential of melanin inhibiting natural products

With the development of society and the improvement of people's living standards, there is an increasing demand for melanin-inhibiting products that prioritize health, safety, and efficacy. Therefore, the development of natural products that can safely and efficiently inhibit melanin synthesis is of great social significance and has significant market potential. In this paper, by reviewing the literature reported in recent years, we summarized the natural products with inhibition of melanin synthesis effects that have been put into or not yet put into the market, and classified them according to the chemical groups of their compounds or the extraction methods of the natural products. Through the summary analysis, we found that these compounds mainly include terpenoids, phenylpropanoids, flavonoids and so on, while the natural product extracts mainly include methanol extracts, ethanol extracts, and aqueous extracts. Their main inhibition of melanin synthesis mechanisms include: (1) direct inhibition of tyrosinase activity; (2) down-regulation of the α-MSH-MC1R, Wnt, NO, PI3K/Akt and MAPK pathways through the expression of MITF and its downstream genes TYR, TRP-1, and TRP-2; (3) antioxidant; (4) inhibition of melanocyte growth through cytotoxicity; (5) inhibition of melanosome production and transport. This paper provides an in-depth discussion on the research progress of whitening natural products and their market value. The aim is to offer guidance for future research and development of natural skin whitening products.

Self-assembled gel microneedle formed by MS deep eutectic solvent as a transdermal delivery system for hyperpigmentation treatment

Hyperpigmentation (HP) is an unfavorable skin disease that typically caused by injury, inflammation, or photoaging and leads to numerous physical and psychological issues in patients. Recently, development and application of natural whitening substances, particularly compound curcumin (CUR), is one of the most prevalent treatments for HP. However, it is still a formidable challenge to improve the percutaneous delivery of CUR due to its inadequate solubility in water and excellent barrier function of skin. To overcome the limitations of conventional delivery and increase the percutaneous absorption of CUR, the efficient delivery of CUR is urgently required. Herein, we developed a new malic acid-sorbitol deep eutectic solvent (MS/DES) gel microneedle loaded with CUR as a transdermal delivery system for HP treatment. The MS/DES gel produces three-dimensional (3D) network structure by self-assembly of hydrogen bond interactions, which conferred the CUR-MS/DES-GMN with sufficient mechanical properties to successfully penetrate skin tissue while also helping to enhance the drug's release rate. The CUR-MS/DES-GMN exhibit high biocompatibility and mechanical property in vivo of mice. The zebrafish experiments also show that CUR-MS/DES gel has significant effect of anti-pigmentation. Therefore, the designed CUR-MS/DES-GMN system provides a novel strategy for HP treatment based on self-assembly of naturally molecules.

Synergistic effect of Panax ginseng, Polygonatum cyrtonema, Epiphyllum oxypetalum, Nelumbo nucifera and Osmanthus fragrans extracts on skin aging regulation. From in silico predictions to in vitro outcome

Intrinsic and extrinsic aging affect the health of human skin. Extracellular matrix protein degradation, DNA damage and oxidative stress are known to disturb skin architecture and skin homeostasis leading to skin aging. Traditional Chinese Medicine (TCM) delivers a large amount of knowledge regarding the phytotherapeutic power of diverse plants. Panax ginseng, Polygonatum cyrtonema, Epiphyllum oxypetalum, Nelumbo nucifera and Osmanthus fragrans are five plants used in TCM for their protective effect. In this study, several combinations of these TCM plants were explored: first, an in silico analysis was performed to predict their potential to target biological activities in the skin and then, some predictions were verified with in vitro studies to underline the synergistic effect of plant extracts. The results showed a stronger anti-aging activity for the combination with the five plants compared to the combination with Panax ginseng, Polygonatum cyrtonema, Epiphyllum oxypetalum and, compared to Panax ginseng alone.

Exploring the potential of white birch sap: A natural alternative to traditional skin whitening agents with reduced side effects

Common tyrosinase (TYR) inhibitors used in cosmetics, such as hydroquinone, kojic acid, and arbutin, can cause side effects including erythema, skin peeling, and dryness. Therefore, the development of natural whitening agents that offer excellent permeability, minimal irritation, and high safety has become a primary focus in the field of TYR inhibitors. In this study, we demonstrate that White birch sap (WBS), within a safe concentration range, effectively reduces TYR activity and melanin content in both B16F10 mouse melanoma cells and zebrafish larvae. Importantly, WBS exhibits minimal irritation to neutrophils in fluorescent zebrafish and does not affect the behavior of adult zebrafish. Furthermore, WBS downregulates the gene expression levels of microphthalmia-associated transcription factor, TYR, tyrosinase-related protein-1, and tyrosinase-related protein-2 in B16F10 cells. In conclusion, our research confirms that WBS, a naturally derived substance, offers high safety and mild effects, making it a promising candidate for a skin-whitening agent.

Studies on Loading Salicylic Acid in Xerogel Films of Crosslinked Hyaluronic Acid

During the last decades, salicylic acid (SA) and hyaluronic acid (HA) have been studied for a wide range of cosmetic and pharmaceutical applications. The current study investigated the drug loading potential of SA in HA-based crosslinked hydrogel films using a post-loading (osmosis) method of the unmedicated xerogels from saturated aqueous solutions of salicylic acid over a range of pH values. The films were characterized with Fourier-transform infra-red spectroscopy (FT-IR) and ultraviolet-visible (UV-Vis) spectrophotometry in order to elucidate the drug loading profile and the films' integrity during the loading process. Additional studies on their weight loss (%), gel fraction (%), thickness increase (%) and swelling (%) were performed. Overall, the studies showed significant film disintegration at highly acidic and basic solutions. No drug loading occurred at neutral and basic pH, possibly due to the anionic repulsion between SA and HA, whereas at, pH 2.1, the drug loading was promising and could be detected via UV-Vis analysis of the medicated solutions, with the SA concentration in the xerogel films at 28% w/w.

1927nm fractional thulium fiber laser combined with 30% salicylic acid for the treatment of acne and acne scars: A prospective, randomized, and split-face study

OBJECTIVES

Patients with acne usually develops acne scars subsequently, early intervention of scars is crucial in acne management. 1927nm fractional thulium fiber laser (TFL) is effective in scars improvement and chemical peels with 30% supramolecular salicylic acid (SSA) can be applied for the treatment of acne. The purpose of this study is to evaluate and compare the efficacy and safety of TFL monotherapy versus the concomitant application of TFL and 30% SSA on acne and acne scars.

MATERIALS AND METHODS

Thirty-three patients with acne and acne scars were enrolled, and two sides of the face were randomly divided to receive either TFL and SSA chemical peeling or TFL. Four sessions of TFL treatments were applied with 4-week intervals for both sides, SSA combined treatment side received eight SSA chemical peels with 2-week intervals additionally. GAGS, ECCA score, the number of acne lesions, melanin index (MI) and erythema index (EI), transepidermal water loss (TEWL), and side effects were recorded at Weeks 0, 4, 8, 12, and 18. Satisfaction of patients was recorded on both sides at the end of the study.

RESULTS

Thirty patients completed the study. Both control group (TFL monotherapy) and SSA group (TFL combined with SSA chemical peeling) significantly improved GAGS and ECCA score. SSA group showed higher efficacy in terms of GAGS and ECCA score, acne lesion count, TEWL, MI, EI, and satisfaction than control group. All the side effects were temporary and tolerable, no adverse effects were observed.

CONCLUSIONS

Both TFL and the TFL combined with 30% SSA chemical peeling are safe and effective for the treatment and prevention of acne and acne scars, though the combined group has higher efficacy.

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

Background

Our 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.

Methods

In vitro and in vivo impact of phenolic acid monomers were assessed.

Results

SA, 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.

Conclusion

P. 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.

In vitro inhibitory effects on free radicals, pigmentation, and skin cancer cell proliferation from Dendrobium hybrid extract: A new plant source of active compounds

Orchidaceae are diverse plants whose bioactive compounds have various biological activities. New hybrids of Dendrobium have been generated to gain characteristics shared with their ancestors. Dendrobium Pearl Vera (designated as DH) is derived from parents used for dermatological treatments and cosmetics. However, the phytoconstituents and biological properties of DH have not been reported. The current study investigated extracts from DH plants using four solvents (water, methanol, ethanol, or 2-propanol). The propanolic extract (DH-P) contained the highest phenolic and flavonoid contents, along with a high scavenging performance for free radicals. In total, 25 tentative constituents in the DH-P matrix were identified, consisting of amino acids, nucleotides, and three types of secondary metabolites: furan, phenolics, and alkaloids. The DH-P inhibited human tyrosinase in vitro in a concentration-dependent manner of the phenolic content. Furthermore, there was no significant difference between DH-P with 10 μg/ml phenolic content and 0.75 mM kojic acid (a commercial whitening agent) on the inhibition of human tyrosinase. Incubation with DH-P containing at least 15 μg/ml phenolic content greatly inhibited the proliferation of human melanoma; however, the cell viability was not affected by the phenolic content at 5 μg/ml or less. The half-maximal inhibitory concentration (IC50) of the phenolic content in DH-P on melanoma viability was 12.90 ± 1.04 μg/ml. Melanin production in vivo by human melanoma incubated with 5 μg/ml phenolic content in DH-P was reduced significantly, compared to 2.5 μg/ml phenolic content in DH-P, 100 μg/ml arbutin, and in control. The identified components, including 5-hydroxymethyl-2-furaldehyde, salicylic acid, nicotinamide, acetophenone, cytidine, adenosine, proline, or valine, have been reported to be associated with depigmentation, antioxidant, and anticancer. This research revealed, for the first time, the tentative phytoconstituents of Dendrobium Pearl Vera and their biological activities, thus demonstrating the potential use of DH-P in dermal applications.

Efficacy and safety of a facial serum and a mask containing salicylic acid and lipohydroxy acid in acne management: A randomized controlled trial

BACKGROUND

Inflammatory and non-inflammatory acne lesions constitute a significant clinical challenge in acne subjects.

AIM

To evaluate the efficacy and safety of a facial serum and a mask containing salicylic acid and lipohydroxy acid for improving skin conditions.

METHODS

This randomized controlled trial included adults with comedones, post-inflammatory erythema (PIE) and/or hyperpigmentation (PIH) in Shanghai, China in July 2021. Participants were randomly assigned 1:1 to receive the study Serum + Mask or serum alone for 8 weeks. Acne severity, comedones, papules, pustules, PIE, PIH, skin pores, skin tone evenness, sebum secretion, skin hydration, and trans-epidermal water loss were evaluated at T0d, T1d, T7d, T14d, T28d, and T56d.

RESULTS

Eighty-three participants were included, including 41 and 42 in the Serum + Mask and Serum groups, respectively. Acne severity, density of skin pores, skin tone evenness, PIH foci on face, PIE foci on nose, intensity of PIE and PIH, closed comedones on face, open comedones on nose, sebum secretion, and skin hydration were significantly improved from baseline after 8 weeks of treatment in both groups (all p < 0.05). Addition of the mask improved the number of closed comedones (-6.56 ± 0.39 vs. -5.19 ± 0.44, p = 0.022) and acne severity (-0.39 ± 0.08 vs. -0.12 ± 0.09, p = 0.026) substantially more than using the serum alone. No adverse reaction was reported in either group.

CONCLUSIONS

The study serum improved skin conditions by regulating skin barrier function and achieving a balance of skin hydration and sebum secretion, removing comedones and improving PIE and PIH. Addition of the mask accelerated the effects without compromising safety.

Skin Pigmentation Types, Causes and Treatment-A Review

Human skin pigmentation and melanin synthesis are incredibly variable, and are impacted by genetics, UV exposure, and some drugs. Patients' physical appearance, psychological health, and social functioning are all impacted by a sizable number of skin conditions that cause pigmentary abnormalities. Hyperpigmentation, where pigment appears to overflow, and hypopigmentation, where pigment is reduced, are the two major classifications of skin pigmentation. Albinism, melasma, vitiligo, Addison's disease, and post-inflammatory hyperpigmentation, which can be brought on by eczema, acne vulgaris, and drug interactions, are the most common skin pigmentation disorders in clinical practice. Anti-inflammatory medications, antioxidants, and medications that inhibit tyrosinase, which prevents the production of melanin, are all possible treatments for pigmentation problems. Skin pigmentation can be treated orally and topically with medications, herbal remedies, and cosmetic products, but a doctor should always be consulted before beginning any new medicine or treatment plan. This review article explores the numerous types of pigmentation problems, their causes, and treatments, as well as the 25 plants, 4 marine species, and 17 topical and oral medications now on the market that have been clinically tested to treat skin diseases.

Characterization and screening of anti-melanogenesis and anti-photoaging activity of different enzyme-assisted polysaccharide extracts from Portulaca oleracea L

BACKGROUND

The flavonoids and polysaccharides in Portulaca oleracea L. (PO) have significant antibacterial and antioxidant effects, which can inhibit common bacteria and remove free radicals in the body. However, there was little research on the use of PO to alleviate hyperpigmentation and photoaging damage.

PURPOSE

This study was to investigate the anti-photoaging and whitening activity mechanism of polysaccharide of PO (POP) in vitro and in vivo.

METHOD

In this study, 16 fractions obtained by four enzyme-assisted extraction from PO and their scavenging capabilities against 2,2-diphenyl-1-picrylhydrazyl and hydroxyl radicals were evaluated. Among these fractions, a polysaccharide fraction (VPOP3) showed the strongest biological activity. VPOP3 was characterized by Fourier-transform infrared spectroscopy, molecular weight (MW), and monosaccharide composition analysis, and the protective effect of VPOP3 on photoaging and hyperpigmentation was researched.

RESULTS

VPOP3 is a low-MW acidic heteropolysaccharide with MW mainly distributed around 0.71KDa, arabinose as its main monosaccharide component. VPOP3 reliably reduced the reactive oxygen species levels in cells and zebrafish and the level of lipid peroxidation in zebrafish. In addition, VPOP3 inhibited UVB-induced apoptotic body formation and apoptosis by downregulating caspase-3 and Bax and upregulating Bcl-2 in mitochondrion-mediated signaling pathways. On the other hand, VPOP3 at high concentrations significantly downregulated the expression of microphthalmia-associated transcription factor, tyrosinase (TYR), and TYR-related protein-1 and TYR-related protein-2 in the melanogenic signaling pathway to achieve a whitening effect.

CONCLUSION

The above results showed that VPOP3 has superior activities of anti-photoaging and anti-melanogenesis and can be utilized as a safe resource in the manufacture of cosmetics.

Targeting Tyrosinase in Hyperpigmentation: Current Status, Limitations and Future Promises

Hyperpigmentation is a common and distressing dermatologic condition. Since tyrosinase (TYR) plays an essential role in melanogenesis, its inhibition is considered a logical approach along with other therapeutic methods to prevent the accumulation of melanin in the skin. Thus, TYR inhibitors are a tempting target as the medicinal and cosmetic active agents of hyperpigmentation disorder. Among TYR inhibitors, hydroquinone is a traditional lightening agent that is commonly used in clinical practice. However, despite good efficacy, prolonged use of hydroquinone is associated with side effects. To overcome these shortcomings, new approaches in targeting TYR and treating hyperpigmentation are desperately requiredessentialneeded. In line with this purpose, several non-hydroquinone lightening agents have been developed and suggested as hydroquinone alternatives. In addition to traditional approaches, nanomedicine and nanotheranostic platforms have been recently proposed in the treatment of hyperpigmentation. In this review, we discuss the available strategies for the management of hyperpigmentation with a focus on TYR inhibition. In addition, alternative treatment options to hydroquinone are discussed. Finally, we present nano-based strategies to improve the therapeutic effect of drugs prescribed to patients with skin disorders.

Phytochemicals as Immunomodulatory Agents in Melanoma

Cutaneous melanoma is an immunogenic highly heterogenic tumor characterized by poor outcomes when it is diagnosed late. Therefore, immunotherapy in combination with other anti-proliferative approaches is among the most effective weapons to control its growth and metastatic dissemination. Recently, a large amount of published reports indicate the interest of researchers and clinicians about plant secondary metabolites as potentially useful therapeutic tools due to their lower presence of side effects coupled with their high potency and efficacy. Published evidence was reported in most cases through in vitro studies but also, with a growing body of evidence, through in vivo investigations. Our aim was, therefore, to review the published studies focused on the most interesting phytochemicals whose immunomodulatory activities and/or mechanisms of actions were demonstrated and applied to melanoma models.

Ginseng glycoprotein and ginsenoside facilitate anti UV damage effects in diabetic rats

Diabetes mellitus combined with ultraviolet (UV) radiation damage not only brings great mental stress to patients, but also seriously impairs their quality of life. A UV-irradiated diabetic rat trauma skin model was established by us to investigate the effects and possible mechanisms of ginsenoside and glycoprotein on skin trauma repair in UV-irradiated diabetic rats. In the study, ginsenosides and ginseng glycoproteins were extracted from different parts of ginseng roots. It found that it's easier to prepare saponins in ginseng bark and proteins in ginseng core in large quantities. Since glycoprotein-like metabolites are relatively novel ginseng extracts, specifically characterized its structures. It was verified that the ginseng glycoproteins are not toxic to HaCaT cells and can significantly increase the survival of HaCaT cells after UV damage at the in vitro cellular level. Experiments in vivo were conducted to evaluate the therapeutic effects of ginsenoside and ginseng glycoprotein in a rat model of diabetes mellitus combined with UV irradiation injury. Histopathological changes on rat skin after treatment with ginsenoside and ginseng glycoprotein were evaluated by hematoxylin and eosin (H&E) staining and aldehyde fuchsine staining. The expression levels of malondialdehyde (MDA), superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), matrix metalloproteinases (MMPs), hydroxyproline (HYP), interleukin-6 (IL-6), interleukin-1β (IL-1β), and tumor necrosis factor-α (TNF-α) were measured. The results indicate that both ginsenoside and ginseng glycoprotein could improve skin damage and ulcers caused by diabetes combined with UV irradiation and could alleviate a range of skin damage caused by the combination of diabetes and UV irradiation, including peroxidation and collagen fiber loss. Ginsenoside and ginseng glycoproteins can be considered as natural product candidates for the development of new drugs to treat diabetes combined with UV irradiation-induced skin damage.

The traditional chinese medicine monomer Ailanthone improves the therapeutic efficacy of anti-PD-L1 in melanoma cells by targeting c-Jun

BACKGROUND

C-Jun, a critical component of AP-1, exerts essential functions in various tumors, including melanoma, and is believed to be a druggable target for cancer therapy. Unfortunately, no effective c-Jun inhibitors are currently approved for clinical use. The advent of immune checkpoint inhibitor (ICI) has brought a paradigm shift in melanoma therapy, but more than half of patients fail to exhibit clinical responses. The exploration of new combination therapies has become the current pursuit of melanoma treatment strategy. This study aims to screen out Chinese herbal monomers that can target c-Jun, explore the combined effect of c-Jun inhibitor and ICI, and further clarify the related molecular mechanism.  METHODS: We adopted a combinatorial screening strategy, including molecular docking, ligand-based online approaches and consensus quantitative structure-activity relationship (QSAR) model, to filter out c-Jun inhibitors from a traditional Chinese medicine (TCM) library. A mouse melanoma model was used to evaluate the therapeutic efficacy of monotherapy and combination therapy. Multicolor flow cytometry was employed to assess the tumor microenvironment (TME). Multiple in vitro assays were performed to verify down-streaming signaling pathway. CD4 + T-cell differentiation assay was applied to investigate Treg differentiation in vitro.

RESULTS

Ailanthone (AIL) was screened out as a c-Jun inhibitor, and inhibited melanoma cell growth by directly targeting c-Jun and promoting its degradation. Surprisingly, AIL also facilitated the therapeutic efficacy of anti-programmed death ligand-1 (PD-L1) in melanoma cells by reducing the infiltration of Tregs in TME. Additionally, AIL treatment inhibited c-Jun-induced PD-L1 expression and secretion. As a consequence, Treg differentiation was attenuated after treatment with AIL through the c-Jun/PD-L1 axis.

CONCLUSION

Our findings identified AIL as a novel c-Jun inhibitor, and revealed its previously unrecognized anti-melanoma effects and the vital role in regulating TME by Treg suppression, which provides a novel combination therapeutic strategy of c-Jun inhibition by AIL with ICI. AIL down-regulates c-Jun by reducing its stability, and inhibits the function of Tregs via AIL-c-Jun-PD-L1 pathway, ultimately suppressing melanoma progression and enhancing the efficacy of anti-PD-L1.

Recent Advances in Herbal-Derived Products with Skin Anti-Aging Properties and Cosmetic Applications

Although aesthetic benefits are a desirable effect of the treatment of skin aging, it is also important in controlling several skin diseases, mainly in aged people. The development of new dermocosmetics has rapidly increased due to consumers' demand for non-invasive products with lower adverse effects than those currently available on the market. Natural compounds of plant origin and herbal-derived formulations have been popularized due to their various safe active products, which act through different mechanisms of action on several signaling pathways for skin aging. Based on this, the aim of the review was to identify the recent advances in herbal-derived product research, including herbal formulations and isolated compounds with skin anti-aging properties. The studies evaluated the biological effects of herbal-derived products in in vitro, ex vivo, and in vivo studies, highlighting the effects that were reported in clinical trials with available pharmacodynamics data that support their protective effects to treat, prevent, or control human skin aging. Thus, it was possible to identify that gallic and ferulic acids and herbal formulations containing Thymus vulgaris, Panax ginseng, Triticum aestivum, or Andrographis paniculata are the most promising natural products for the development of new dermocosmetics with skin anti-aging properties.

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.

Heat-Killed Lacticaseibacillus paracasei Ameliorated UVB-Induced Oxidative Damage and Photoaging and Its Underlying Mechanisms

Ultraviolet B (UVB) radiation is a major environmental causative factor of skin oxidative damage and photoaging. Lacticaseibacillus paracasei is a well-known probiotic strain that can regulate skin health. The present study investigated the effects of heat-killed Lacticaseibacillus paracasei (PL) on UVB linked oxidative damage and photoaging in skin cells (Normal human dermal fibroblast (NHDF) cells and B16F10 murine melanoma cells). Results demonstrated that: (1) PL prevented UVB-induced cytotoxicity relating to decreased DNA damage in NHDF and B16F10 cells; (2) PL alleviated UVB-induced oxidative damage through increasing GSH content, as well as antioxidant enzyme activities and mRNA levels (except MnSOD activity and mRNA levels as well as CAT mRNA level) relating to the activation of Sirt1/PGC-1α/Nrf2 signaling in NHDF cells; (3) PL attenuated UVB-induced photoaging was noticed with a decrease in the percentage of SA-β-gal positive cells in NHDF cells model. Moreover, PL attenuated UVB-induced photoaging through exerting an anti-wrinkling effect by enhancing the type I collagen level relating to the inhibition (JNK, p38)/(c-Fos, c-Jun) of signaling in NHDF cells, and exerting an anti-melanogenic effect by suppressing tyrosinase and TYRP-1 activity and/or expressions relating to the inhibition of PKA/CREB/MITF signaling in B16F10 cells. In conclusion, PL could ameliorate UVB-induced oxidative damage and photoaging. Therefore, PL may be a potential antioxidant and anti-photoaging active ingredient for the cosmetic industry.