Overview of Skin Whitening Agents: Drugs and Cosmetic Products

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.

Discovery of Indole-Thiourea Derivatives as Tyrosinase Inhibitors: Synthesis, Biological Evaluation, Kinetic Studies, and In Silico Analysis

Tyrosinase, a key enzyme in melanin synthesis, represents a crucial therapeutic target for hyperpigmentation disorders due to excessive melanin production. This study aimed to design and evaluate a series of indole-thiourea derivatives by conjugating thiosemicarbazones with strong tyrosinase inhibitory activity to indole. Among these derivatives, compound 4b demonstrated tyrosinase inhibitory activity with an IC50 of 5.9 ± 2.47 μM, outperforming kojic acid (IC50 = 16.4 ± 3.53 μM). Kinetic studies using Lineweaver-Burk plots confirmed competitive inhibition by compound 4b. Its favorable ADMET and drug-likeness properties make compound 4b a promising therapeutic candidate with a reduced risk of toxicity. Molecular docking revealed that the compounds bind strongly to mushroom tyrosinase (mTYR) and human tyrosinase-related protein 1 (TYRP1), with compound 4b showing superior binding energies of -7.0 kcal/mol (mTYR) and -6.5 kcal/mol (TYRP1), surpassing both kojic acid and tropolone. Molecular dynamics simulations demonstrated the stability of the mTYR-4b complex with low RMSD and RMSF and consistent Rg and SASA values. Persistent strong hydrogen bonds with mTYR, along with favorable Gibbs free energy and MM/PBSA calculations (-19.37 kcal/mol), further support stable protein-ligand interactions. Overall, compound 4b demonstrated strong tyrosinase inhibition and favorable pharmacokinetics, highlighting its potential for treating pigmentary disorders.

Rutin of Moringa oleifera as a potential inhibitor to Agaricus bisporus tyrosinase as revealed from the molecular dynamics of inhibition

Tyrosinase is a binuclear copper-containing enzyme that catalyzes the conversation of monophenols to diphenols via o-hydroxylation and then the oxidation of o-diphenols to o-quinones which is profoundly linked to eukaryotic melanin synthesis and fruits browning. The hyperpigmentation due to unusual tyrosinase activity has gained growing health concern. Plants and their metabolites are considered promising and effective sources for potent antityrosinase enzymes. Hence, searching for potent, specific tyrosinase inhibitor from different plant extracts is an alternative approach in regulating overproduction of tyrosinase. Among the tested extracts, the hydro-alcoholic extract of Moringa oleifera L. leaves displayed the potent anti-tyrosinase activity (IC50 = 98.93 µg/ml) in a dose-dependent manner using L-DOPA as substrate; however, the kojic acid showed IC50 of 88.92 µg/ml. The tyrosinase-diphenolase (TYR-Di) kinetic analysis revealed mixed inhibition type for the Ocimum basilicum L. and Artemisia annua L. extracts, while the Coriandrum sativum L. extract displayed a non-competitive type of inhibition. Interestingly, the extract of Moringa oleifera L. leaves exhibited a competitive inhibition, low inhibition constant of free enzyme ( K ii app ) value and no Pan-Assay Interfering Substances, hinting the presence of strong potent inhibitors. The major putative antityrosinase compound in the extract was resolved, and chemically identified as rutin based on various spectroscopic analyses using UV-Vis, FTIR, mass spectrometry, and 1H NMR. The in silico computational molecular docking has been performed using rutin and A. bisporus tyrosinase (PDB code: 2Y9X). The binding energy of the predicted interaction between tropolone native ligand, kojic acid, and rutin against 2Y9X was respectively - 5.28, - 4.69, and - 7.75 kcal/mol. The docking simulation results revealed the reliable binding of rutin to the amino acid residues (ASN260, HIS259, SER282) in the tyrosinase catalytic site. Based on the developed results, rutin extracted from M. oleifera L. leaves has the capability to be powerful anti-pigment agent with a potential application in cosmeceutical area. In vivo studies are required to unravel the safety and efficiency of rutin as antityrosinase compound.

The dark side of beauty: an in-depth analysis of the health hazards and toxicological impact of synthetic cosmetics and personal care products

Over the past three decades, the popularity of cosmetic and personal care products has skyrocketed, largely driven by social media influence and the propagation of unrealistic beauty standards, especially among younger demographics. These products, promising enhanced appearance and self-esteem, have become integral to contemporary society. However, users of synthetic, chemical-based cosmetics are exposed to significantly higher risks than those opting for natural alternatives. The use of synthetic products has been associated with a variety of chronic diseases, including cancer, respiratory conditions, neurological disorders, and endocrine disruption. This review explores the toxicological impact of beauty and personal care products on human health, highlighting the dangers posed by various chemicals, the rise of natural ingredients, the intricate effects of chemical mixtures, the advent of nanotechnology in cosmetics, and the urgent need for robust regulatory measures to ensure safety. The paper emphasizes the necessity for thorough safety assessments, ethical ingredient sourcing, consumer education, and collaboration between governments, regulatory bodies, manufacturers, and consumers. As we delve into the latest discoveries and emerging trends in beauty product regulation and safety, it is clear that the protection of public health and well-being is a critical concern in this ever-evolving field.

De novo biosynthesis of β-arbutin in Corynebacterium glutamicum via pathway engineering and process optimization

BACKGROUND

β-Arbutin, a hydroquinone glucoside found in pears, bearberry leaves, and various plants, exhibits antioxidant, anti-inflammatory, antimicrobial, and anticancer effects. β-Arbutin has wide applications in the pharmaceutical and cosmetic industries. However, the limited availability of high-performance strains limits the biobased production of β-arbutin.

RESULTS

This study established the β-arbutin biosynthetic pathway in C. glutamicum ATCC13032 by introducing codon-optimized ubiC, MNX1, and AS. Additionally, the production titer of β-arbutin was increased by further inactivation of csm and trpE to impede the competitive metabolic pathway. Further modification of the upstream metabolic pathway and supplementation of UDP-glucose resulted in the final engineered strain, C. glutamicum AR11, which achieved a β-arbutin production titer of 7.94 g/L in the optimized fermentation medium.

CONCLUSIONS

This study represents the first successful instance of de novo β-arbutin production in C. glutamicum, offering a chassis cell for β-arbutin biosynthesis.

Chemical analysis of marine microdebris pollution in macroalgae from the coastal areas of Argentina

Marine microdebris (MDs, <5 mm) and mesodebris (MesDs, 5-25 mm), consist of various components, including microplastics (MPs), antifouling or anticorrosive paint particles (APPs), and metallic particles (Mmps), among others. The accumulation of these anthropogenic particles in macroalgae could have significant implications within coastal ecosystems because of the role of macroalgae as primary producers and their subsequent transfer within the trophic chain. Therefore, the objectives of this study were to determine the abundance of MDs and MesDs pollution in different species of macroalgae (P. morrowii, C. rubrum, Ulva spp., and B. minima) and in surface waters from the Southwest Atlantic coast of Argentina to evaluate the ecological damage. MDs and MesDs were chemically characterized using μ-FTIR and SEM/EDX to identify, and assess their environmental impact based on their composition and degree of pollution by MPs, calculating the Polymer Hazard Index (PHI). The prevalence of MDs was higher in foliose species, followed by filamentous and tubular ones, ranging from 0 to 1.22 items/g w.w. for MPs and 0 to 0.85 items/g w.w. for APPs. It was found that macroalgae accumulate a higher proportion of high-density polymers like PAN and PES, as well as APPs based on alkyd, PMMA, and PE resins, whereas a predominance of CE was observed in surrounding waters. Potentially toxic elements, such as Cr, Cu, and Ti, were detected in APPs and MPs, along with the presence of epiplastic communities on the surface of APPs. According to PHI, the presence of high hazard score polymers, such as PAN and PA, increased the overall risk of MP pollution in macroalgae compared to surrounding waters. This study provided a baseline for MDs and MesDs abundance in macroalgae as well as understanding the environmental impact of this debris and their bioaccumulation in the primary link of the coastal trophic chain.

Melanin Inhibitory Effect of Tuber himalayense Isolated in Incheon, Korea

There has been a growing interest in skin beauty and antimelanogenic products. Melanogenesis is the process of melanin synthesis whereby melanocytes are activated by UV light or hormone stimulation to produce melanin. Melanogenesis is mediated by several enzymes, such as tyrosinase (TYR), microphthalmia-associated transcription factor (MITF), tyrosinase-related protein-1 (TRP-1), and TRP-2. In this study, we investigated the effect of Tuber himalayense extract on melanin synthesis in α-melanocyte-stimulating hormone (α-MSH)-treated B16F10 melanoma cells. We confirmed that T. himalayense extract was not toxic to α-MSH-treated B16F10 melanoma cells and exhibited a significant inhibitory effect on melanin synthesis at concentrations of 25, 50, and 100 μg/ml. Additionally, the T. himalayense extract inhibited melanin, TRP-1, TRP-2, tyrosinase, and MITF, which are enzymes involved in melanin synthesis, in a concentration-dependent manner. Furthermore, T. himalayense extract inhibited the mitogen-activated protein kinase (MAPK) pathways, such as extracellular signal-regulated kinase-1/2 (ERK), c-Jun N-terminal kinase (JNK), and p38. Therefore, we hypothesized that various components of T. himalayense extract affect multiple factors involved in melanogenesis in B16F10 cells. Our results indicate that T. himalayense extract could potentially be used as a new material for preparing whitening cosmetics.

Comparative Studies on the Photoreactivity, Efficacy, and Safety of Depigmenting Agents

Depigmenting products are increasingly used to counteract skin hyperpigmentation and related psychosocial issues. This study aimed to compare different depigmenting agents-4-butylresorcinol; bakuchiol; tranexamic acid; ascorbyl glucoside; α-arbutin; and ascorbic acid-for photoreactivity; tyrosinase inhibition; and safety. Photoreactivity was assessed using the Reactive Oxygen Species assay. In vitro tyrosinase inhibition was compared, and cell viability was assessed in B-16V melanocytes to evaluate safety. Results showed 4-butylresorcinol, ascorbyl glucoside, and α-arbutin are non-photoreactive, while for ascorbic acid and bakuchiol it was not possible to reach conclusive results due to the lack of specificity of the ROS assay. 4-Butylresorcinol, acting as a competitive inhibitor, displayed potent tyrosinase inhibition, followed by ascorbic acid and bakuchiol. Both 4-butylresorcinol and bakuchiol reduced cell viability in a concentration-dependent manner. The insights obtained in this work support the development of depigmenting products by providing useful scientific guidance on the photostability, tyrosinase inhibitory efficacy, and skin safety of depigmenting agents.

Plant Extracts as Skin Care and Therapeutic Agents

Natural ingredients have been used for centuries for skin treatment and care. Interest in the health effects of plants has recently increased due to their safety and applicability in the formulation of pharmaceuticals and cosmetics. Long-known plant materials as well as newly discovered ones are increasingly being used in natural products of plant origin. This review highlights the beneficial effects of plants and plant constituents on the skin, including moisturizing (e.g., Cannabis sativa, Hydrangea serrata, Pradosia mutisii and Carthamus tinctorius), anti-aging (e.g., Aegopodium podagraria, Euphorbia characias, Premna odorata and Warburgia salutaris), antimicrobial (e.g., Betula pendula and Epilobium angustifolium), antioxidant (e.g., Kadsura coccinea, Rosmarinus officinalis, Rubus idaeus and Spatholobus suberectus), anti-inflammatory (e.g., Antidesma thwaitesianum, Helianthus annuus, Oenanthe javanica, Penthorum chinense, Ranunculus bulumei and Zanthoxylum bungeanum), regenerative (e.g., Aloe vera, Angelica polymorpha, Digitaria ciliaris, Glycyrrihza glabra and Marantodes pumilum), wound healing (e.g., Agrimonia eupatoria, Astragalus floccosus, Bursera morelensis, Jatropha neopauciflora and Sapindus mukorossi), photoprotective (e.g., Astragalus gombiformis, Calea fruticose, Euphorbia characias and Posoqueria latifolia) and anti-tyrosinase activity (e.g., Aerva lanata, Bruguiera gymnorhiza, Dodonaea viscosa, Lonicera japonica and Schisandra chinensis), as well as their role as excipients in cosmetics (coloring (e.g., Beta vulgaris, Centaurea cyanus, Hibiscus sabdariffa and Rubia tinctiorum), protective and aromatic agents (e.g., Hyssopus officinalis, Melaleuca alternifolia, Pelargonium graveolens and Verbena officinalis)).

The effect of low-intensity cold atmospheric plasma jet on photoaging-induced hyperpigmentation in mouse model

BACKGROUND

Cold atmospheric plasma (CAP) produces reactive oxygen/nitrogen species (RONS) in the target and can induce cytoprotective effects by activating hormesis-related pathways when its intensity is in the low range.

OBJECTIVES

The aim of this study is to evaluate the effect of low-intensified CAP (LICAP) on skin with photoaging-induced hyperpigmentation in an animal model.

METHODS

Changes in cell viability and RONS production following LICAP treatment were measured. For the in vivo study, 30 hairless mice underwent antecedent photoaging induction followed by the allocated therapy (i.e., LICAP, topical ascorbic acid (AA), or both). During the first 4 weeks of the treatment period (8 weeks), ultraviolet (UV)-B irradiation was concurrently administered. Visual inspection and measurement of the melanin index (MI) were performed to assess the change in skin pigmentation at Weeks 0, 2, 4, 6, and 8.

RESULTS

RONS production increased linearly until the saturation point. Cell viability was not significantly affected by LICAP treatment. At Week 8, MI was significantly decreased in every treatment group compared with the values at Week 0 and Week 4. The treatment effect of the concurrent therapy group was superior to that of the LICAP and AA groups.

CONCLUSION

LICAP appears to be a novel modality for photoprotection and pigment reduction in photodamaged skin. LICAP treatment and topical AA application seem to exert a synergistic effect.

Concern on Skin Lightening Product Safety: Level of Awareness and Associated Factors Among Female Users in Bahir Dar City, Ethiopia

Background

Most skin lightening products are composed of some toxic chemicals such as mercury and hydroquinone which are classified under critical ingredients which need evaluation. Consumption without sufficient awareness may lead to toxicities endangering skin health.

Objective

The aim of this study was to assess the level of awareness towards the side effects of skin lightening products and associated factors among females in Bahir Dar city, Ethiopia.

Methods

An institutional-based cross-sectional study design was conducted in Bahir Dar city from June 28 to August 28, 2022 among females that had been using skin whitening. Samples of 362 females were selected by using multistage sampling technique from selected drug retail outlets. The data was coded, cleaned, and analyzed by using SPSS version 26. The variables were analyzed through multiple regression in order to identify the associated factors towards the level of awareness on the side effects of skin lightening products.

Results

Only 42.7% of the respondents had a favorable level of awareness. The highly influencing factors for using skin lightening products were peer pressure (39.9%) and social media (37.4%). Nearly half of the users experienced side effects. Only 8.9% of the respondents know the active ingredients of the products. Level of education was found to have significant association with level of awareness (AOR = 7.66, 95% CI: (1.23, 47.59); P = 0.029).

Conclusion

Only less than half of women have favorable awareness towards skin lightening products they use. The significant association between educational level and level of awareness should be considered as an alternative intervention in addition to regulatory restrictions.

Fabrication of polyvinyl pyrrolidone-K90/Eudragit RL100-based dissolving microneedle patches loaded with alpha-arbutin and resveratrol for skin depigmentation

Alpha-arbutin (AA) and resveratrol (Res) are widely used in skin-lightening products. However, current topical formulations have minimal skin-lightening effects due to the low absorption and poor solubility of these active compounds. This study investigated the efficacy and safety of using dissolving microneedle (DMN) patches to improve the delivery of AA and Res for skin depigmentation. The DMN patches (F0-F3) fabricated from polyvinyl pyrrolidone-K90 (PVP-K90)/Eudragit RL100 blends successfully penetrated excised porcine skin and showed sufficient mechanical strength to resist compression forces. Loading DMNs with 10% AA and 2% Res at a ratio of 5 : 1 (F3) resulted in a synergistic interaction between the drugs with desirable dissolving ability, drug loading, and stability. Furthermore, both in vitro and in vivo studies revealed that the use of F3 DMN patches successfully enhanced the intradermal delivery of AA and Res over a 24 h period, with the delivered amount being higher (∼2.6 times) than that provided by a cream formulation (P < 0.05). After removing the DMN patches, the mice's skin was spontaneously and completely resealed within 12 h. In clinical studies, F3 DMN patches slightly decreased the melanin index of the participants without causing skin irritation or erythema at any time during the 24 h period when the patches were applied (P < 0.05). Moreover, application of the patches for 24 h was not found to affect skin hydration, transepidermal water loss, or skin elasticity. Therefore, AA/Res-loaded DMN patches could offer a promising approach for the effective local delivery of cosmetic agents for skin depigmentation.

Anti-Melanogenic Effects of Fractioned Cynanchum atratum by Regulation of cAMP/MITF Pathway in a UVB-Stimulated Mice Model

Based on traditional pharmacological applications and partial in vitro data, Cynanchum atratum (CA) is proposed to act on skin whitening. However, its functional evaluation and underlying mechanisms have yet to be identified. This study aimed to examine the anti-melanogenesis activity of CA fraction B (CAFB) on UVB-induced skin hyperpigmentation. Forty C57BL/6j mice were exposed to UVB (100 mJ/cm², five times/week) for eight weeks. After irradiation, CAFB was applied to the left ear once a day for 8 weeks (the right ear served as an internal control). The results showed that CAFB significantly reduced melanin production in the ear skin, as indicated by the gray value and Mexameter melanin index. In addition, CAFB treatment notably decreased melanin production in α-MSH-stimulated B16F10 melanocytes, along with a significant reduction in tyrosinase activity. Cellular cAMP (cyclic adenosine monophosphate), MITF (microphthalmia-associated transcription factor), and tyrosinase-related protein 1 (TRP1) were also noticeably downregulated by CAFB. In conclusion, CAFB is a promising ingredient for treating skin disorders caused by the overproduction of melanin and its underlying mechanisms involving the modulation of tyrosinase, mainly mediated by the regulation of the cAMP cascade and MITF pathway.

Simultaneous HPLC Determination of Arbutin, Niacinamide and 3-O-Ethyl Ascorbic Acid in Whitening Cream Products in the Presence of Parabens

Arbutin, niacinamide and 3-O-ethyl ascorbic acid (a new generation of vitamin C derivatives) are compounds that have a whitening effect on skin and are widely used in whitening cream products wherein parabens such as methyl paraben, ethyl paraben, propyl paraben and butyl paraben are also often added as preservatives. This study aims to develop a validated high-performance liquid chromatography (HPLC) method that can be used to determine arbutin, niacinamide and 3-O-ethyl ascorbic acid simultaneously in whitening cream products without interference from the parabens. The optimum conditions for the HPLC system were obtained using ODS-3 RP-C18 Inertsil column, mobile phase consisting of a mixture of aquabides, methanol and acetonitrile with gradient elution mode. Detection was carried out using a UV detector at 220 nm. Validation studies demonstrated a good linearity for all analytes over each range concentration with a correlation coefficient >0.999 and Vx0 < 2%. The accuracy test also met the requirements with the recoveries being 96.93-99.55%, 98.60-99.73% and 97.88-100.63% for arbutin, niacinamide and 3-O-ethyl ascorbic acid, respectively. Intra-day and inter-day precision test gave a relative standard deviation (% RSD) of <2% along with a HorRat value of <2 for all analytes. The results of this study indicate that the developed HPLC method has a good selectivity, linearity, accuracy and precision. Due to its simplicity, the method can be used to analyze arbutin, niacinamide and 3-O-ethyl ascorbic acid in the presence of parabens in whitening cream products simultaneously.

Exploiting HOPNO-dicopper center interaction to development of inhibitors for human tyrosinase

In human, Tyrosinase enzyme (TyH) is involved in the key steps of protective pigments biosynthesis (in skin, eyes and hair). The use of molecules targeting its binuclear copper active site represents a relevant strategy to regulate TyH activities. In this work, we targeted 2-Hydroxypyridine-N-oxide analogs (HOPNO, an established chelating group for the tyrosinase dicopper active site) with the aim to combine effects induced by combination with a reference inhibitor (kojic acid) or natural substrate (tyrosine). The HOPNO-MeOH (3) and the racemic amino acid HOPNO-AA compounds (11) were tested on purified tyrosinases from different sources (fungal, bacterial and human) for comparison purposes. Both compounds have more potent inhibitory activities than the parent HOPNO moiety and display strictly competitive inhibition constant, in particular with human tyrosinase. Furthermore, 11 appears to be the most active on the B16-F1 mammal melanoma cells. The investigations were completed by stereospecificity analysis. Racemic mixture of the fully protected amino acid 10 was separated by chiral HPLC into the corresponding enantiomers. Assignment of the absolute configuration of the deprotected compounds was completed, based on X-ray crystallography. The inhibition activities on melanin production were tested on lysates and whole human melanoma MNT-1 cells. Results showed significant enhancement of the inhibitory effects for the (S) enantiomer compared to the (R) enantiomer. Computational studies led to an explanation of this difference of activity based for both enantiomers on the respective position of the amino acid group versus the HOPNO plane.

Quantification of Arbutin in Cosmetics, Drugs and Food Supplements by Hydrophilic-Interaction Chromatography

Arbutin, the glucoside of hydroquinone, exists in two isomers, α-arbutin and β-arbutin. The synthetic α isomer is mainly used as a skin brightening agent, while β-arbutin occurs naturally, for instance in bearberry, and is used in drugs for treatment of lower urinary tract infections and as a food supplement. Since both isomers can be harmful at high concentrations, methods for their quantification are required. Classically they have been determined by reversed-phase chromatography, but separation of both isomers is often unsatisfactory. Here we present a simple and reliable method for quantification of α- and β-arbutin based on hydrophilic-interaction chromatography. Prior to analysis, interfering compounds that would frequently be present in cosmetics and drugs, particularly biopolymers, were efficiently removed by precipitation with acetonitrile. In this paper, for separation, a Cyclobond I 2000 5 µm 250 × 4.6 mm column was employed as stationary phase and acetonitrile/water 92/8 (v/v) was used as an eluent at a flow rate of 0.8 mL min−1. For quantification, a UV detector operating at 284 nm was applied. Although analysis took less than 10 min, baseline separation of α- and β-arbutin was achieved. The response was highly linear (r > 0.999) and the method had, for both α- and β-arbutin, a LOD of 0.003% (w/w) and a LOQ of 0.009% (w/w). Moreover, the method showed excellent intra-day and inter-day repeatability with relative standard deviations in the range of 0.5% to 2.3% and 1.0% to 2.2%, respectively, with cosmetics, drugs and food supplements as samples.

Daphne odora Exerts Depigmenting Effects via Inhibiting CREB/MITF and Activating AKT/ERK-Signaling Pathways

Daphne odora, a blooming shrub, has been traditionally used for various medicinal purposes. However, information on its anti-melanogenic activity and dermal application is limited. In this study, the Daphne odora extract (DOE), with constituents including daphnetin, was used to investigate depigmenting activity and the underlying mechanism of Daphne odora. DOE inhibited in vitro and cellular tyrosinase activity in a dose-dependent manner, and reduced the α-MSH-induced melanin biosynthesis to a control level. The protein expressions of melanin synthesis-related enzymes were also significantly reduced by DOE. Moreover, DOE decreased the phosphorylation of cAMP-response element binding proteins (CREBs) induced by α-MSH in B16F10 cells, while it activated phosphorylated extra-cellular signal-regulated kinases (ERKs) and protein kinase B (AKT) expression. These results suggest that DOE might inhibit the melanogenesis signaling pathways by activating ERK- and AKT-signaling pathways to regulate the expression of CREB and MITF and its downstream pathways. Therefore, DOE could potentially be developed as a depigmenting agent.

Review on the Use of Kojic Acid—A Skin-Lightening Ingredient

This article reviews the use of Kojic Acid (KA) as a skin-lightening ingredient in the cosmetics industry. In 1907, Saito discovered KA, a natural product; it has since become one of the most investigated skin-lightening agents. This paper highlights the findings of the research conducted on this agent. It has been found that KA has certain disadvantages, and researchers have attempted to mitigate these disadvantages by designing new equivalents of KA that are more efficient in tyrosinase inhibition. These equivalents are also safe to use and have improved properties and solubility. The Cosmeceutical Ingredient Review (CIR) indicates that this ingredient can be safely used at a concentration not higher than 1% due to its cytotoxicity. Other scientific data also support its safety at a concentration of 2% or less. It was shown to be helpful in the treatment of hyper pigmentary disorders, such as freckles, age spots, post-inflammatory hyperpigmentation, and melasma, which has been proven clinically.

Phytoecdysteroids from Serratula coronata L. for Psoriatic Skincare

Phytoecdysones from Serratula coronata seem to be promising agents for skincare in patients with psoriasis. The aim of the study was to determine the effects of creams containing the extract of S. coronata on psoriatic lesions. Creams with different formulas were prepared: 0-Lekobaza^®, 1-Lekobaza^®, S. coronata, 2-Lekobaza^®, Salicylic acid, 3-Lekobaza^®, S. coronata, Salicylic acid. After examination of skin penetration and biosafety, the designated cream was applied twice daily for 6 weeks on 72 psoriatic plaques located on elbows or knees. The lesions were assessed at baseline and follow-up of 6 weeks. The lesions area was measured, and severity of scaling, erythema, and infiltration was assessed using a 5-point scale (from 0—none to 4—very severe). Skin hydration and structure, pH, transepidermal water loss, erythema, and melanin index were analyzed instrumentally. Creams 1, 2, and 3 significantly reduced the area of psoriatic plaques. Improvement in erythema and infiltration was observed for creams 1 and 3. Creams 1–3 reduced scaling. Our study confirmed a beneficial effect of creams containing S. coronata extract on psoriatic lesions.

Recent Progress on Feasible Strategies for Arbutin Production

Arbutin is a hydroquinone glucoside and a natural product present in various plants. Arbutin potently inhibits melanin formation. This property has been exploited in whitening cosmetics and pharmaceuticals. Arbutin production relies mainly on chemical synthesis. The multi-step and complicated process can compromise product purity. With the increasing awareness of sustainable development, the current research direction prioritizes environment-friendly, biobased arbutin production. In this review, current strategies for arbutin production are critically reviewed, with a focus on plant extraction, chemical synthesis, biotransformation, and microbial fermentation. Furthermore, the bottlenecks and perspectives for future direction on arbutin biosynthesis are discussed.

By-product of Korean liquor fermented by Saccharomyces cerevisiae exhibits skin whitening activity

Herein, the skin whitening effect of the fermentation residue of Saccharomyces cerevisiae was investigated. The fermentation residue showed radical scavenging activity and attenuated tyrosinase activity. Furthermore, the fermentation residue of S. cerevisiae significantly suppressed melanin generation in B16F10 cells. Interestingly, the sample-containing formulation exhibited increased skin whitening activity compared with that by the control formulation in a clinical study. Notably, the endogenous tyrosinase expression was not altered by the fermentation residue of S. cerevisiae; however, the enzymatic activity of tyrosinase was inhibited. Furthermore, the sample did not change TRP1 and TRP2 expression in B16F10 cells. Thus, the fermentation residue of S. cerevisiae was assumed to directly suppress the tyrosinase enzyme. It was confirmed that the fermentation residue of S. cerevisiae was a competitive inhibitor of tyrosinase. Taken together, the fermentation residue of S. cerevisiae could be a novel skin whitening agent originating from the traditional Korean liquor production process.

Supplementary Information

The online version contains supplementary material available at 10.1007/s10068-022-01062-7.

Spreading of Dangerous Skin-Lightening Products as a Result of Colourism: A Review

The use of bleaching products can have a medical or cosmetic purpose; in the latter case, skin whitening is most widespread in countries where darker skin tones prevail and can be driven by psychosocial, cultural and economic reasons. Skin-whitening products containing highly toxic active ingredients (in particular mercury derivatives, hydroquinone and corticosteroids) are easily found on the market; the use of these depigmenting agents can be followed by a variety of adverse effects, with very serious and sometimes fatal complications, and is currently an emerging health concern in many countries. This article concisely discusses the reasons for the current prevalence of skin lightening products and provides an overview of the skin lightening agents that pose a threat to human health. The review also reports market surveillance data on the circulation of banned skin lighteners in Europe, obtained through the Safety Gate system.

Potency of moringa (Moringa oleifera L.) leaves extract containing quercetin as a depigmentation agent inhibiting the tyrosinase enzyme using in-silico and in-vitro assay

Hyperpigmentation is a disorder of facial skin pigments due to an increase in the process of melanogenesis, which can cause a darkening of skin color. A flavonoid compound with potential as a skin-lightening agent is quercetin, commonly found in Moringa oleifera L. leaves. This study aims to determine quercetin’s affinity and molecular mechanism on tyrosinase enzyme target proteins using an in-silico molecular docking method. Docking of quercetin with the tyrosinase enzyme produced a bond energy value of -7.08 kcal/mol. In comparison, the tropolone as a native ligand with the tyrosinase enzyme produced -4.79 kcal/mol. Quercetin has a strong affinity for the tyrosinase enzyme, indicated by the bond energy results from docking. Quercetin extraction from Moringa oleifera L. leaves using three different extraction methods: maceration, soxhlation, and reflux were made. The chromatogram from the TLC-Densitometry method showed the identification result in maceration and soxhlation extract containing quercetin, while reflux extract did not contain quercetin. The highest quercetin was obtained in the maceration method with a level of 21.57% w/w, while the soxhlation received quercetin as much as 18.49% w/w. In-vitro tests were carried out using a spectrophotometric method using a comparison of kojic acid. The in-vitro test found that IC50 from kojic acid was 48.90 µg/mL and IC50 of the extract from moringa leaf maceration of 115.36 µg/mL. Based on this research, quercetin compounds in Moringa oleifera L. leaves from maceration can potentially be skin-lightening agents.

Skin Depigmenting Agents in Anti-Aging Cosmetics: A Medicinal Perspective on Emerging Ingredients

Human skin aging results from intrinsic and extrinsic factors. Uneven pigmentation is one of the major changes of extrinsic aging. Many compounds have been tested for depigmenting activity but only a few are actually used by the cosmetic industry, which is continually looking for new ingredients. In this study, the trends in the use of skin depigmenting ingredients in a panel of anti-aging formulations commercialized in the Portuguese pharmacy market were analyzed, by comparing the composition of the products marketed in 2011 with products launched or reformulated in 2018 (59% and 74%, respectively). The analysis of the top 12 ingredients put forward three novelties for 2018: tranexamic acid, bakuchiol, and 4-butylresorcinol. Regarding their mechanisms of action, tranexamic acid inhibits melanin synthesis through inhibition of the plasminogen/plasmin system. Bakuchiol depigmenting efficacy was attributed to the ability to block both α-melanocyte-stimulating hormone and tyrosinase activation, while 4-butylresorcinol exerts its action through the inhibition of both tyrosinase and tyrosinase-related protein-1 (TRP-1). Industry-optimized and efficient synthetic methodologies that embrace green chemistry, reducing the environmental impact, are commonly used. This analysis aims to bring insights to both formulators, involved in the development of depigmenting cosmetic products, and chemists performing the synthesis of new and existing compounds intended for this purpose.

Preparation of Readily-to-Use Stilbenoids Extract from Morus alba Callus Using a Natural Deep Eutectic Solvent

The consumer and cosmetic industries have recently placed a greater emphasis on ecofriendly solvents for botanical extraction, including natural deep eutectic solvents (NADES). In this study, NADES were prepared for Morus alba callus extraction. The efficiency of extraction from the NADES and methanol was investigated by comparison of the stilbenoids yield and anti-melanogenesis activity. Prior to testing the irritability of a suitable NADES on the reconstructed human epidermis (RhE), the effect of the selected NADES on stilbenoids stability was determined. The results showed that the highest yields of stilbenoids were obtained from choline chloride-glycerol mixtures (Ch1G2) and methanol extracts, with no significant difference in yields (5.06 ± 0.05 and 6.32 ± 0.40 mg/g callus dry weight, respectively). The NADES extracts of M. alba callus showed comparable anti-melanogenesis activity compared to methanol. In term of stability, stilbenoids in Ch1G2 remained stable after six months of storage at 4 °C except resveratrol. Furthermore, Ch1G2 had no irritation effect on RhE. Thus, based on the findings of this study, Ch1G2 is an intriguing green solvent alternative for the extraction of M. alba callus and may be advantageous for the preparation of skin-lightening cosmetics.

Fractional Erbium:YAG Laser (2940 nm) plus Topical Hydroquinone Compared to Intradermal Tranexamic Acid plus Topical Hydroquinone for the Treatment of Refractory Melasma: A Randomized Controlled Trial

OBJECTIVES

Melasma is a chronic acquired condition characterized by grayish-brown macules and patches with a distinct border on the face. Although various treatments methods have been suggested for treating melasma, none has been completely successful. The aim of the study was to compare the efficiency of erbium: yttrium-aluminum-garnet (Er:YAG) laser and 4% hydroquinone (HQ) with the effects of intradermal tranexamic acid (TA) and 4% HQ for the treatment of refractory melasma.

METHODS

The study included 31 female patients with refractory melasma. The left or right side of the patient's face was chosen randomly to receive laser therapy with topical HQ on the one side (i.e., the laser side) and intradermal injection of TA plus topical HQ on the other side (i.e., the mesotherapy side). Digital photography was performed at baseline, at the end of the treatment, and three months after the treatment as follow-up. Two independent dermatologists evaluated the modified Melasma Area and Severity Index (mMASI) score according to the pictures. Overall, 27 patients completed the study and went through the clinical evaluation.

RESULTS

Treatment using HQ in combination with either Er:YAG laser therapy or intradermal injection of TA significantly improved the hemi-mMASI and resulted in higher patient satisfaction. While the improvement was not significantly different between the two regiments after the treatment and upon follow up and both were equally efficient in the treatment of refractory melasma (p = 1.308), recurrence rate was higher after treatment with Er:YAG laser than TA (12% vs 34%).

CONCLUSION

This study confirmed the comparable efficacy of TA plus topical HQ versus Er:YAG laser plus topical HQ for the treatment of refractory melasma. Both groups improved significantly and no subject left the treatment because of adverse effects.

Skin-Lightening Products: Consumer Preferences and Costs

Disorders of skin hyperpigmentation have an appreciable impact on quality of life, carrying social and cultural importance that influences widespread consumer demand for cosmetic lightening products. We sought to investigate product factors that may influence consumer preference when choosing an over-the-counter cream for skin-lightening purposes. The keyword "lightening cream" was searched in the "Beauty and Personal Care category" of online retailer Amazon.com. The top fifth percentile of products was determined by filtering the search results for a minimum of four out of five stars from customer reviews, and then further filtered by products with over 100 reviews. Number of reviews, rating, price per unit, vehicle, application instructions, ingredients, and review attributes were evaluated. Over 2,900 products were catalogued as "lightening cream" on Amazon.com. There were 40 products rated >4 stars and >100 reviews, constituting the top 1.34% of entries. Tocopheryl was present in 58% of the top 40 products, ascorbic acid in 40%, and niacinamide in 20%. Notably, 22.5% of the top 40 products contained no known skin-lightening ingredient. There was a moderate positive correlation (R2=0.378) between price and consumer rating, with kojic acid being the most expensive per ounce ($24.89) and salicylic acid being the most highly rated (4.54 stars; $15.00/oz). This study provides insight on the factors influencing the choice, preferences, and satisfaction of consumer that sought Amazon for the purchase of lightening products.

Nanostructured Ethosomal Gel Loaded with Arctostaphylos uva-ursi extract; In-vitro/In-vivo Evaluation as a Cosmeceutical Product

BACKGROUND

Arctostaphylos uva-ursi (AUU) being rich in polyphenols and arbutin is known to have promising biological activities and can be a potential candidate as a cosmaceutical. Ethosomes encourage the formation of lamellar-shaped vesicles with improved solubility and entrapment of many drugs including plant extracts.

OBJECTIVE

The objective of this work was to develop an optimized nanostructured ethosomal gel formulation loaded with AUU extract and evaluated for skin rejuvenation and depigmentation.

METHODS

AUU extract was tested for phenolic and flavonoid content, radical scavenging potential, reducing power activity, and in-vitro SPF (sun protection factor) estimation. AUU loaded 12 formulations were prepared and characterized by SEM (scanning electron microscopy), vesicular size, zeta potential, and entrapment efficiency (%EE). The optimized formulation was subjected to non-invasive in-vivo investigations after incorporating it into the gel system and ensuring its stability and skin permeation.

RESULTS

Ethosomal vesicles were spherical in shape and Zeta size, zeta potential, PDI (polydispersity index), % EE and in-vitro skin permeation of optimized formulation (F3) were found to be 114.7nm, -18.9mV, 0.492, 97.51±0.023%, and 79.88±0.013% respectively. AUU loaded ethosomal gel formulation was stable physicochemically and exhibited non-Newtonian behavior rheologically. Moreover, it significantly reduced skin erythema, melanin as well as sebum level and improved skin hydration and elasticity.

CONCLUSION

A stable AUU based ethosomal gel formulation could be a better vehicle for phytoextracts than conventional formulations for cosmeceutical applications such as for skin rejuvenation and depigmentation etc.

Determination of Phenolic Content, Antioxidant Activity, and Tyrosinase Inhibitory Effects of Functional Cosmetic Creams Available on the Thailand Market

Recently, the global trend toward the use of natural extracts and antioxidant agents in the cosmetic cream industry to produce whitening effects has been increasing. This has also been a persistent trend in Thailand. In this study, samples of commercial cosmetic creams on the Thai market were assessed for a functional evaluation of their antioxidant activity, tyrosinase inhibitory effects, and phenolic contents. Samples were extracted using hot water and sonication extraction method to obtain the functional cream extracts. Total phenolic contents in all samples were within the range of 0.46-47.92 mg GAE/30 g cream. Antioxidant activities of the cream extracts were within the range of 3.61-43.98 mg Trolox equivalent/30 g cream, while tyrosinase inhibition activities were within the range of 2.58-97.94% of inhibition. With regard to the relationship between the total phenolic content and the antioxidant activity of the cosmetic creams, Pearson's correlation coefficient revealed a moderately positive relationship with an r value of 0.6108. Furthermore, the relationship between the antioxidant activity and the tyrosinase inhibitory activity of the cosmetic creams was highly positive with an r value of 0.7238. Overall, this study demonstrated that the total phenolic contents in the functional cosmetic creams could play a role in antioxidant activity and anti-tyrosinase activities. The findings indicate how the whitening and antioxidant effects of cosmetic creams could be maintained after the products have been formulated, as this concern can affect the consumer's decision when purchasing cosmetic products.

Skin hyperpigmentation and its treatment with herbs: an alternative method

Background

With an increasing number of patients, those who are facing a lot of skin-related complaints, often referred to as skin of pigmentation patients, are on the rise. Among all the most common complaints in patients with skin of color is hyperpigmentation. So, there is need of herbal formulation for treatment of hyperpigmentation.

Main body

This review article addresses the different types of hyperpigmentation, causes, and its treatment with herbs for the management of the skin hyperpigmentation. As uneven pigmentation of skin or hyperpigmentation is a common skin condition, which occurs when the skin produces more melanin. This can make spots or patches of skin appear darker than surrounding areas. Some forms of hyperpigmentation with post-inflammatory, melasma, and sun spots are more likely to affect areas of face, arms, and legs due to sun exposure and injury. Although the availability of multiple treatments for the condition which leads to some adverse effects, hyperpigmentation continues to present skin care management challenges for dermatologists.

Conclusion

Some plants and phytoconstituents, e.g., Azadirachta indica, Glycyrrhiza glabra, Panax ginseng and genistein, ellagic acids, quercetin, are very useful in herbal cosmetic as anti-hyperpigmentry agents in cosmetic industries. Some of flavonoids and triterpenoids present in plants also show their effect as antioxidant and skin whitening agents. It is expected that this review will compile and improve the existing knowledge on the potential utilization of herbs for the treatment of skin hyperpigmentation.

The New Challenge of Green Cosmetics: Natural Food Ingredients for Cosmetic Formulations

Nowadays, much attention is paid to issues such as ecology and sustainability. Many consumers choose “green cosmetics”, which are environmentally friendly creams, makeup, and beauty products, hoping that they are not harmful to health and reduce pollution. Moreover, the repeated mini-lock downs during the COVID-19 pandemic have fueled the awareness that body beauty is linked to well-being, both external and internal. As a result, consumer preferences for makeup have declined, while those for skincare products have increased. Nutricosmetics, which combines the benefits derived from food supplementation with the advantages of cosmetic treatments to improve the beauty of our body, respond to the new market demands. Food chemistry and cosmetic chemistry come together to promote both inside and outside well-being. A nutricosmetic optimizes the intake of nutritional microelements to meet the needs of the skin and skin appendages, improving their conditions and delaying aging, thus helping to protect the skin from the aging action of environmental factors. Numerous studies in the literature show a significant correlation between the adequate intake of these supplements, improved skin quality (both aesthetic and histological), and the acceleration of wound-healing. This review revised the main foods and bioactive molecules used in nutricosmetic formulations, their cosmetic effects, and the analytical techniques that allow the dosage of the active ingredients in the food.

New Insight into the Interactions of Arbutin with Mushroom Tyrosinase

As a safe substitute for hydroquinone, β-arbutin, a natural plant substance, and its synthetic counterpart, α-arbutin, are used in depigmentation formulations. However, there are debatable points regarding the impact of arbutin on tyrosinase and the pigmentation process. To shed light on this issue, the effects of Pyrus biossieriana leaves extract (PbLE) and β-arbutin, extracted from PbLE, on mushroom tyrosinase (MT) were comprehensively examined. The study was focused on cresolase activity as the characteristic reaction of a tyrosinase. Kinetics studies disclosed that β-arbutin can modulate MT monophenolase activity from inhibition to activation or vice versa. β-Arbutin inhibited L-tyrosine (LTy) oxidation at concentrations < 0.3 mM but it increased (more than 400%) the enzymatic oxidation of L-tyrosine at the concentrations > 0.3 mM. An opposite pattern (activation then inhibition) was observed when a synthetic substrate was used instead of LTy. Computational studies, focused on the heavy chain of MT, indicated that β-arbutin effect could be overruled by the enzyme's ability to provide the ligand with a non-specific binding site (MTPc). A plausible mechanism was presented to show the influence of MTPc on the substrate pose in the active site. The possible determinant correlation between the findings of this research and the current studies on human tyrosinase role in the pigmentation process has been presented.

Novel Quercetin Derivative of 3,7-Dioleylquercetin Shows Less Toxicity and Highly Potent Tyrosinase Inhibition Activity

Quercetin is a well-known plant flavonol and antioxidant; however, there has been some debate regarding the efficacy and safety of native quercetin as a skin-whitening agent via tyrosinase inhibition. Several researchers have synthesized quercetin derivatives as low-toxicity antioxidants and whitening agents. However, no suitable quercetin derivatives have been reported to date. In this study, a novel quercetin derivative was synthesized by the S_N2 reaction using quercetin and oleyl bromide. The relationship between the structures and activities of quercetin derivatives as anti-melanogenic agents was assessed using in vitro enzyme kinetics, molecular docking, and quenching studies; cell line experiments; and in vivo zebrafish model studies. Novel 3,7-dioleylquercetin (OQ) exhibited a low cytotoxic concentration level at >100 µg/mL (125 µM), which is five times less toxic than native quercetin. The inhibition mechanism showed that OQ is a competitive inhibitor, similar to native quercetin. Expression of tyrosinase, tyrosinase-related protein 1 (TRP-1) and tyrosinase-related protein 2 (TRP-2), and microphthalmia-associated transcription factor was inhibited in B16F10 melanoma cell lines. mRNA transcription levels of tyrosinase, TRP-1, and TRP-2 decreased in a dose-dependent manner. Melanin formation was confirmed in the zebrafish model using quercetin derivatives. Therefore, OQ might be a valuable asset for the development of novel skin-whitening agents.

Facial Skin Biophysical Profile of Women in Malaysia: Significance of Facial Skincare Product Use

INTRODUCTION

At present, there is a lack of baseline data on the facial skin biophysical profile of women in Malaysia. The implications related to the daily habits and facial skincare product use on the skin biophysical condition are, thus, unknown. In this study, we aim to evaluate facial skin biophysical parameters of Malaysian women and examine the influence of demographic characteristics, daily habits, and facial skincare product use on these parameters.

METHODS

Four skin biophysical parameters - transepidermal water loss (TEWL), melanin content, elasticity, and collagen intensity - were assessed on the cheek of the subjects (20-60 years). Demographic background, daily habits, and skincare product use were gauged through a survey. Only 197 from the 213 subjects recruited initially were used for analysis after the data were screened for normality.

RESULTS

The biophysical parameters were similar in different races, except a higher melanin content in Indian female individuals. Elasticity and collagen intensity reduced with age, while melanin content increased in the older age-groups. But no difference was observed in TEWL at different ages. Evaluating the influence of daily habits, we observed that exercise significantly lowered TEWL and increased melanin content, which may be associated with UV radiation exposure. Facial skincare products are popular among the female subjects (>85% users). Products with moisturizing, sunscreening, and other skincare functions (astringent, antiaging, and anti-wrinkle) were preferred by subjects of all ages. These product functions significantly improve skin elasticity and reduce melanin content in the young adults. While aged women recognized the importance of having an additional skin-lightening function in their skincare routine. Although the influence of individual skincare function on skin biophysical parameters was mostly positive, the alteration of these parameters varied at different ages.

CONCLUSION

This is the first report of facial skin biophysical profile of Malaysian women. There is no difference among 3 major races saved for melanin content. This work demonstrated age-dependent influences on the biophysical parameters, except TEWL. The significance of skincare product use is well reflected in the improvement of these parameters at different age-groups based on individual skincare functions.

Novel bioactive formulation derived from the conditioned medium of mesenchymal stromal cells reduces under-eye dark circles in human volunteers

BACKGROUND

Under-eye dark circles are a common condition observed in dermatology practice. Mesenchymal stromal cell-derived conditioned medium (MSC-CM) contains an array of growth factors and cytokines reported to promote periorbital rejuvenation and may be useful in removing the dark circle around the eyes.

AIMS

The aim of the present study was to evaluate the safety and efficacy of developed bioactive formulation containing mesenchymal stromal cell-derived conditioned medium in reducing the under-eye dark circles.

PATIENTS/METHODS

We tested the safety profile of MSC-CM along with antioxidants, in vitro using human melanocytes cultures. The bioactive formulation containing MSC-CM was developed and tested for physicochemical parameters. The dermatological safety was evaluated by primary irritant patch-test under complete occlusion on healthy human subjects. To elucidate its safety and efficacy, monocentric, open-label, single-arm study was carried out in 20 Indian female subjects for the duration of 12 weeks. Parameters such as eye puffiness, radiance, skin smoothness, even skin tone, periorbital fine lines and wrinkles, crow's feet, whitening, pigmentation, skin tightening, and refreshing/soothing effect were used to investigate the rejuvenating property of the bioactive formulation.

RESULTS

Mesenchymal stromal cell-derived conditioned medium along with antioxidants decreased the melanin content compared to the CM alone in the melanocyte cultures. Besides, the bioactive formulation was safe and emerged as a non-irritant product. Improvement in the majority of the clinical parameters assessed through efficacy study was observed within 4 weeks of topical application of the formulation twice daily, and showed continued improvement for 12 weeks as evaluated by the dermatologists as well as self-assessment by the subjects.

CONCLUSION

The bioactive formulation containing MSC-CM was safe and effective in reducing the under-eye dark circles and was beneficial in improving the overall appearance of the eye area.

A comprehensive review of the therapeutic potential of α-arbutin

Cosmetic dermatology preparations such as bleaching agents are ingredients with skin-related biological activities for increasing and improving skin beauty. The possibility of controlling skin hyperpigmentation disorders is one of the most important research goals in cosmetic preparations. Recently, cosmetics containing herbal and botanical ingredients have attracted many interests for consumers of cosmetic products because these preparations are found safer than other preparations with synthetic components. However, high-quality trial studies in larger samples are needed to confirm safety and clinical efficacy of phytotherapeutic agents with high therapeutic index. Arbutin (p-hydroxyphenyl-β-d-glucopyranoside) is a bioactive hydrophilic polyphenol with two isomers including alpha-arbutin (4-hydroxyphenyl-α-glucopyranoside) and β-arbutin (4-hydroxyphenyl-β-glucopyranoside). It is used as a medicinal plant in phytopharmacy. Studies have shown that alpha-arbutin is 10 times more effective than natural arbutin. A comparison of IC50 values showed that α-arbutin (with concentration 2.0 mM) has a more potent inhibitory activity on human tyrosinase against natural arbutin (with higher concentration than 30 mM). A review of recent studies showed that arbutin could be beneficial in treatment of various diseases such as hyperpigmentation disorders, types of cancers, central nervous system disorders, osteoporosis, diabetes, etc. This study was designed to describe the therapeutic efficiencies of arbutin.

Comparison of 2% deoxyarbutin and 4% hydroquinone as a depigmenting agent in healthy individuals: A double-blind randomized controlled clinical trial

BACKGROUND

Hydroquinone, which is considered the gold standard skin depigmenting agent, has been associated with multiple side effects. Lately, deoxyarbutin has been suggested to be an alternative of hydroquinone with better safety profile.

OBJECTIVE

To compare the depigmenting effect of 2% deoxyarbutin and 4% hydroquinone sera.

METHODS

This double-blind randomized controlled study was done on the right and left arms of healthy participants. Subjects were instructed to apply either 2% deoxyarbutin or 4% hydroquinone serum on each arm, which were randomly labeled as group A and B, every day for 12 weeks. Chromameter and mexameter analysis were done every 2 weeks to assess the color change. Paired and independent t-tests were used to assess the color change within and between both groups, respectively.

RESULTS

A total of 59 females participated in this study. Both groups showed significant improvement in skin depigmentation as shown by the chromameter (increase in L* value) and mexameter (decrease in melanin index) analysis at the end of the study (p < 0.05). No significant difference in both parameters was observed between both groups (p > 0.05). No side effects were reported in either groups.

CONCLUSION

2% deoxyarbutin and 4% hydroquinone sera showed comparable depigmenting efficacy.

In vitro antioxidant and antityrosinase activities of Manilkara kauki

Manilkara kauki L. Dubard is a tropical plant in the genus Manilkara of family Sapotaceae. This study investigated the total phenolic and flavonoid contents, and antioxidant and antityrosinase activities in different parts of M. kauki (fruits, leaves, seeds, stem barks and woods) and in fractions of stem barks. The total phenolic and flavonoid contents of the methanol and aqueous crude extracts of different parts of M. kauki ranged from 10.87 to 176.56 mg GAE (gallic acid equivalents) per gram of crude extract and 14.33 to 821.67 mg QE (quercetin equivalents) per gram of crude extract, resp. Leaves and stem barks exhibited higher total phenolic and flavonoid contents and antioxidant and anti-tyrosinase activities than fruits, seeds and woods. Stem barks were sequentially extracted with n-hexane, ethyl acetate, methanol and water and then the fractionated extracts were subjected to antioxidant and antityrosinase activities testing. The ethyl acetate and methanol extracts of stem barks exhibited higher total phenolic and flavonoid contents and antioxidant and antityrosinase activities than the n-hexane and aqueous extracts. Moreover, ethyl acetate extract of M. kauki stem exhibited the highest antityrosinase activity. It may be a potential source of tyrosinase inhibitors for pharmaceutical and cosmetic applications.

Combination and efficiency: preparation of dissolving microneedles array loaded with two active ingredients and its anti-pigmentation effects on guinea pigs

Hyperpigmentation is a common skin disorder caused by excessive melanogenesis and uneven dispersion of melanin in the skin. To combine multiple active agents with an efficient transdermal drug delivery system is an effective strategy to combat UV induced skin pigmentation. In this work, Arbutin (Arb) and Vitamin C (Vc) mixed in 1:1 were found to have the greatest inhibition effects on melanogenesis and tyrosinase activity in B16 murine melanoma cells. And hyaluronic acid (HA) based dissolving microneedles array (DMNA) was employed to overcome the skin barriers for improved topical drug delivery, which exhibited the most desirable features, including morphology, mechanical properties, dissolving ability, and the highest drug loading. Furthermore, DMNA could greatly increase the stability of Vc during storage without adding any antioxidant which is an important issue for Vc administration. Pharmacodynamics study showed that DMNA loaded with Arb and Vc could synergistically suppress UVB-induced hyperpigmentation in guinea pig skin. This work provides a promising treatment strategy and solution for skin pigmentation and other skin problems.

Molecular Mechanisms of Anti-Melanogenic Gedunin Derived from Neem Tree (Azadirachta indica) Using B16F10 Mouse Melanoma Cells and Early-Stage Zebrafish

Melanogenesis represents a series of processes that produce melanin, a protective skin pigment (against ultraviolet rays), and determines human skin color. Chemicals reducing melanin production have always been in demand in the cosmetic market because of skincare interests, such as whitening. The main mechanism for inhibiting melanin production is the inhibition of tyrosinase (TYR), a key enzyme for melanogenesis. Here, we evaluated gedunin (Ged), a representative limonoid, for its anti-melanogenesis action. Melanin production in vitro was stimulated by alpha-melanocyte stimulating hormone (α-MSH) in B16F10 mouse melanoma cells. Ged reduced α-MSH-stimulated melanin production, inhibiting TYR activity and protein amount. We confirmed this result in vivo in a zebrafish model for melanogenesis. There was no sign of toxicity and malformation of zebrafish embryos during development in all treated concentrations. Ged reduced the number of produced zebrafish embryo pigment dots and melanin contents of embryos. The highly active concentration of Ged (100 µM) was much lower than the positive control, kojic acid (8 mM). Hence, Ged could be a fascinating candidate for anti-melanogenesis reagents.

Additive Effect of a Combination of Artocarpus lakoocha and Glycyrrhiza glabra Extracts on Tyrosinase Inhibition in Melanoma B16 Cells

Artocarpus lakoocha (Al) and Glycyrrhiza glabra (Gg) extracts have been reported to show tyrosinase inhibitory activity and melanin pigment reduction. This is the first study to assess the combination of Al and Gg extracts in enhancing inhibition of tyrosinase and reduction of melanin pigments. Al and Gg extracted by maceration in 70% and 95% ethanol were analyzed for oxyresveratrol and glabridin using Ultra High Performance Liquid Chromatography. Extracts of Al and Gg singly and combinations of Al95 and Gg95 were tested for cytotoxicity, tyrosinase inhibitory activity, and reduction of melanin pigments in melanoma B16 cells. Al95 had higher antioxidant, tyrosinase inhibitory activity and reduced more melanin pigments in B16 cells compared to Al70, and exhibited higher levels of oxyresveratrol. Gg95 inhibited oxidative stress and mushroom tyrosinase better than Gg70, and exhibited higher levels of glabridin. Combinations of Al95 and Gg95 at various ratios (concentration of 0.1 mg/mL) were not cytotoxic to B16 cells. Interestingly, Al95 and Gg95 combined at a ratio 9:1 reduced melanin pigment up to 53% in B16 cells. This combination of Al95 and Gg95 extracts exhibited the additive effect of reducing melanin pigments by suppressing the expression of microphthalmia-associated transcription factor (MITF), tyrosinase (TYR) and tyrosinase-related protein-2 (TRP-2) in B16 cells. The combination of Al and Gg extracts could be developed as skin care products for hyperpigmentation treatment.

The anticarcinogen activity of β-arbutin on MCF-7 cells: Stimulation of apoptosis through estrogen receptor-α signal pathway, inflammation and genotoxicity

Arbutin is one of the active ingredients employed in cosmetics as a skin whitening agent. In the present study, the possible effects of arbutin on breast cancer were determined with human breast adenocarcinoma (MCF-7) cells. α and β-arbutin cytotoxicity levels in MCF-7 cells were determined with the MTT method. At low (1-10 mM) doses, α-arbutin appears to be more toxic than β-arbutin. At higher (5-200 mM) and LD₅₀ doses beta arbutin toxicity appears to be higher than alpha arbutin. Thus, the study was continued with β -arbutin. The effects of low and high doses of β-arbutin was determined on oxidative stress, genotoxicity, inflammation, apoptosis, proliferation, endoplasmic reticulum stress and estrogen receptor-α in MCF-7 cells. The results demonstrated that the β-arbutin doses administered to MCF-7 cells did not affect oxidative and endoplasmic reticulum stress in the experimental groups. However, it was found that administration of LD₅₀ dose β-arbutin induced inflammation in these cells via proinflammatory cytokine levels (TNF-α, IFN-γ and IL-1β). It was observed that LD₁₀ and LD₅₀ doses of β-arbutin increased genotoxicity in MCF-7 cells. The gene expression analysis conducted with RT-PCR device and immunocytochemical analysis revealed that β-arbutin at LD₅₀ dose induced apoptosis in MCF-7 cells via p53 and Caspase 3. Furthermore, it was determined that all β-arbutin doses inhibited estrogen receptor-α in MCF-7 cells. Considering that arbutin increased the activation of apoptotic Caspase 3 through p53, which was stimulated by genotoxic and inflammatory effects at LD₅₀ dose in MCF-7 cells. Determination of this mechanism behind these effects of β-arbutin may contribute to the development of a new perspective in treatment.

Tyrosinase and Melanogenesis Inhibition by Indigenous African Plants: A Review

The indiscriminate use of non-regulated skin lighteners among African populations has raised health concerns due to the negative effects associated with skin lightener toxicity. For this reason, there is a growing interest in the cosmetic development of plants and their metabolites as alternatives to available chemical-derived skin lightening formulations. Approximately 90% of Africa’s population depends on traditional medicine, and the continent’s biodiversity holds plant material with various biological activities, thus attracting considerable research interest. This study aimed to review existing evidence and document indigenous African plant species capable of inhibiting the enzyme tyrosinase and melanogenesis for potential incorporation into skin lightening products. Literature search on melanin biosynthesis, skin lightening, and tyrosinase inhibitors resulted in the identification of 35 plant species were distributed among 31 genera and 21 families across 15 African countries and 9 South African provinces. All plants identified in this study showed competent tyrosinase and melanogenesis inhibitory capabilities. These results indicate that African plants have the potential to serve as alternatives to current chemically-derived skin lighteners.

Synthesis and Studies of the Inhibitory Effect of Hydroxylated Phenylpropanoids and Biphenols Derivatives on Tyrosinase and Laccase Enzymes

The impaired activity of tyrosinase and laccase can provoke serious concerns in the life cycles of mammals, insects and microorganisms. Investigation of inhibitors of these two enzymes may lead to the discovery of whitening agents, medicinal products, anti-browning substances and compounds for controlling harmful insects and bacteria. A small collection of novel reversible tyrosinase and laccase inhibitors with a phenylpropanoid and hydroxylated biphenyl core was prepared using naturally occurring compounds and their activity was measured by spectrophotometric and electrochemical assays. Biosensors based on tyrosinase and laccase enzymes were constructed and used to detect the type of protein-ligand interaction and half maximal inhibitory concentration (IC50). Most of the inhibitors showed an IC50 in a range of 20-423 nM for tyrosinase and 23-2619 nM for laccase. Due to the safety concerns of conventional tyrosinase and laccase inhibitors, the viability of the new compounds was assayed on PC12 cells, four of which showed a viability of roughly 80% at 40 µM. In silico studies on the crystal structure of laccase enzyme identified a hydroxylated biphenyl bearing a prenylated chain as the lead structure, which activated strong and effective interactions at the active site of the enzyme. These data were confirmed by in vivo experiments performed on the insect model Tenebrio molitur.

Fabrication, characterization and comparison of α-arbutin loaded dissolving and hydrogel forming microneedles

In this study, polyacrylic acid-co-maleic acid (PAMA) and polyvinyl alcohol (PVA) (1:4) were used to fabricate dissolving microneedles (DMNs) and hydrogel forming microneedles (HMNs) which incorporated α-arbutin. Αlpha-arbutin is commonly used as a skin lightening agent. However, it has poor penetration ability due to its hydrophilic properties. The purpose of this study was to compare the permeation of α-arbutin into the skin using DMNs and HMNs. Both types of microneedles (MNs) were sharp, strong with elegant appearance and approximately 100% penetrated the neonatal porcine skin. All needles of α-arbutin loaded DMNs were completely dissolved within 45 min, whereas maximum swelling of HMNs was observed at 4 h. In vitro permeation studies showed that α-arbutin loaded DMNs and HMNs provided significantly about 4.5 and 2.8 times, respectively, greater α-arbutin permeability than gel and commercial cream (P < 0.05). In vivo study also showed high intradermal delivery of α-arbutin levels using DMNs (5.33 µg/mL) and HMNs (1.47 µg/mL) when compared to that of commercial cream 0.15 µg/mL. Moreover, the micro-holes caused by applying MNs can reseal within 1 h. MNs were also stable at 25 °C for 3 months. The results suggested that DMNs and HMNs developed have a promising platform for transdermal delivery.

Efficacy of a collagen hydrolysate and antioxidants-containing nutraceutical on metrics of skin health in Indian women

BACKGROUND

The skin's aging process involves a decreased biosynthesis of extracellular matrix proteins (predominantly collagen) compounded by damage from environmental and intrinsic stressors. The Indian population is susceptible to skin damage given its geography and increasing urbanization or a genetic disposition. Previous studies have investigated nutrients such as collagen peptides, vitamins and phytonutrient-rich botanical extracts for their individual benefits on skin.

AIMS

This study examined the collective effect of a proprietary blend of these nutrients (in Nutrova Collagen+Antioxidants; NCA) on skin parameters, which has not been previously studied, especially in an Indian context.

PATIENTS/METHODS

34 healthy, Indian women (mean age = 39.5 years) were given a placebo daily for 30 days to establish a baseline, followed by NCA for two intervals of 30 days. 3D image reconstruction allowed the analysis of skin topography and blemishes. Instrumental measurements also included skin firmness, elasticity, hydration, and transepidermal water loss. Clinical evaluation was used to grade blemishes, wrinkles and periorbital hyperpigmentation.

RESULTS

Based on instrumental evaluation, NCA significantly reduced wrinkle width, open pores, skin roughness, and the colour of hyperpigmented blemishes, while improving skin hydration, firmness and barrier function from baseline to Day 30 and Day 60. NCA also increased elasticity at Day 30. Clinical evaluation showed that periorbital hyperpigmentation and wrinkles reduced significantly.

CONCLUSION

NCA is effective for improving overall skin health in Indian women. These results show that targeted nutrient supplementation can improve skin health and further research over extended durations is merited.

Enhancement of the Antioxidant, Anti-Tyrosinase, and Anti-Hyaluronidase Activity of Morus alba L. Leaf Extract by Pulsed Electric Field Extraction

In this study we aimed to compare the chemical composition and biological activity between Morus alba L. leaf extract obtained with 95% v/v ethanol using a pulsed electric field (PEF) and the conventional maceration method. Extracts of M. alba leaves collected from Chiang Mai (CM), Sakon Nakon (SK), and Buriram (BR), Thailand, were investigated for 1-deoxynojirimycin content by high-performance liquid chromatography and for total phenolic content by the Folin–Ciocalteu method. Antioxidant activity was investigated by 2,2′-diphenyl-1-picrylhydrazyl (DPPH), 2,2’-azinobis-3-ethylbenzothiazoline-6-sulphonate (ABTS), and ferric reducing antioxidant power (FRAP) assay. Anti-tyrosinase and anti-hyaluronidase activity was investigated by in vitro spectrophotometry. The results show that this is the first study to indicate PEF as a novel method for enhancing the phenolic content and antioxidant, anti-tyrosinase, and anti-hyaluronidase activity of M. alba leaf extract (P < 0.05). PEF extract of M. alba leaves collected from BR had comparable ABTS^•+ scavenging activity to l-ascorbic acid and comparable anti-tyrosinase activity to kojic acid (P > 0.05). On the other hand, PEF extract of M. alba leaves collected from SK exhibited significantly high anti-hyaluronidase activity, comparable to that of oleanolic acid (P > 0.05). Therefore, PEF is suggested for further M. alba leaf extraction in the production of natural whitening and anti-aging cosmetic ingredients.

Natural anti-aging skincare: role and potential

The deterioration of the skin morphology and physiology is the first and earliest obvious harbinger of the aging process which is progressively manifested with increasing age. Such deterioration affects the vital functions of the skin such as homeodynamic regulation of body temperature, fluid balance, loss of electrolytes and proteins, production of vitamin D, waste removal, immune surveillance, sensory perception, and protection of other organs against deleterious environmental factors. There are, however, harmful chemicals and toxins found in everyday cosmetics that consumers are now aware of. Thus, the natural beauty industry is on the rise with innovative technology and high-performance ingredients as more consumers demand healthier options. Therefore, the aims of this review are to give some critical insights to the effects of both intrinsic and extrinsic factors on excessive or premature skin aging and to elaborate on the relevance of natural beauty and natural anti-aging skincare approaches that will help consumers, scientists and entrepreneurs make the switch. Our recent investigations have shown the potential and relevance of identifying more resources from our rich natural heritage from various plant sources such as leaves, fruits, pomace, seeds, flowers, twigs and so on which can be explored for natural anti-aging skincare product formulations. These trending narratives have started to gain traction among researchers and consumers owing to the sustainability concern and impact of synthetic ingredients on human health and the environment. The natural anti-aging ingredients, which basically follow hormetic pathways, are potentially useful as moisturizing agents; barrier repair agents; antioxidants, vitamins, hydroxy acids, skin lightening agents, anti-inflammatory ingredients, and sunblock ingredients.