Rhododenol Activates Melanocytes and Induces Morphological Alteration at Sub-Cytotoxic Levels

Syringaresinol Attenuates α-Melanocyte-Stimulating Hormone-Induced Reactive Oxygen Species Generation and Melanogenesis

Ginseng has been utilized for centuries in both the medicinal and cosmetic realms. Recent studies have actively investigated the biological activity of ginseng berry and its constituents. (+)-Syringaresinol [(+)-SYR], an active component of ginseng berry, has been demonstrated to have beneficial effects on the skin, but its potential impact on skin pigmentation has not been fully explored. Here, the antioxidant and anti-pigmentary activity of (+)-SYR were evaluated in B16F10 murine melanoma cells and in an artificial human pigmented skin model, Melanoderm™. A real-time PCR, Western blotting, immunofluorescence staining, and histochemistry staining were conducted to confirm the effects of (+)-SYR on pigmentation. (+)-SYR reduced melanogenesis and dendrite elongation in α-melanocyte-stimulating hormone (α-MSH)-primed B16F10 cells with low cytotoxicity. (+)-SYR suppressed the expression of melanogenic genes, namely tyrosinase (TYR), tyrosinase-related protein 1 (TRP-1), and tyrosinase-related protein 2 (TRP-2). Notably, (+)-SYR attenuated α-MSH-induced cytosolic and mitochondrial reactive oxygen species (ROS) generation, which was attributable at least in part to the suppression of NADPH oxidase-4 (NOX 4) expression. Finally, the brightening activities of (+)-SYR were verified using Melanoderm™, underscoring the potential of ginseng berry and (+)-SYR as functional ingredients in skin-brightening cosmetics.

Nano-Chitosan/Eucalyptus Oil/Cellulose Acetate Nanofibers: Manufacturing, Antibacterial and Wound Healing Activities

Accelerated wound healing in infected skin is still one of the areas where current therapeutic tactics fall short, which highlights the critical necessity for the exploration of new therapeutic approaches. The present study aimed to encapsulate Eucalyptus oil in a nano-drug carrier to enhance its antimicrobial activity. Furthermore, in vitro, and in vivo wound healing studies of the novel nano-chitosan/Eucalyptus oil/cellulose acetate electrospun nanofibers were investigated. Eucalyptus oil showed a potent antimicrobial activity against the tested pathogens and the highest inhibition zone diameter, MIC, and MBC (15.3 mm, 16.0 μg/mL, and 256 μg/mL, respectively) were recorded against Staphylococcus aureus. Data indicated a three-fold increase in the antimicrobial activity of Eucalyptus oil encapsulated chitosan nanoparticle (43 mm inhibition zone diameter against S. aureus). The biosynthesized nanoparticles had a 48.26 nm particle size, 19.0 mV zeta potential, and 0.45 PDI. Electrospinning of nano-chitosan/Eucalyptus oil/cellulose acetate nanofibers was conducted, and the physico-chemical and biological properties revealed that the synthesized nanofibers were homogenous, with a thin diameter (98.0 nm) and a significantly high antimicrobial activity. The in vitro cytotoxic effect in a human normal melanocyte cell line (HFB4) proved an 80% cell viability using 1.5 mg/mL of nano-chitosan/Eucalyptus oil/cellulose acetate nanofibers. In vitro and in vivo wound healing studies revealed that nano-chitosan/Eucalyptus oil/cellulose acetate nanofibers were safe and efficiently enhanced the wound-healing process through enhancing TGF-β, type I and type III collagen production. As a conclusion, the manufactured nano-chitosan/Eucalyptus oil/cellulose acetate nanofiber showed effective potentiality for its use as a wound healing dressing.

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.

Comparative Study of Δ9-Tetrahydrocannabinol and Cannabidiol on Melanogenesis in Human Epidermal Melanocytes from Different Pigmentation Phototypes: A Pilot Study

Δ9-tetrahydrocannabinol (THC) is one of the primary ingredients of cannabis plants and is responsible for the psychoactive properties of cannabis. While cannabidiol (CBD), the non-psychoactive compound from cannabis, has been shown to stimulate human epidermal melanogenesis, the effects of THC have not been addressed in human epidermal melanocytes. Moreover, to date, no study has tested the effects of these compounds on melanocytes differing in pigmentation, representative of different skin phototypes, which would be significant as different ethnicities are known to differentially metabolize these xenobiotics. Herein, the effects of THC were studied and compared alongside CBD in human epidermal melanocytes derived from lightly-pigmented (HEMn-LP; Caucasian) and darkly-pigmented (HEMn-DP; African-American) cells over a chronic exposure of 6 d. Results demonstrated that both compounds displayed cytotoxicity at 4 µM but stimulated melanin synthesis and tyrosinase activity in a similar manner in LP and DP cells at nontoxic concentrations of 1-2 µM. However, THC and CBD showed a differential effect on dendricity in both cells; THC and CBD reversibly increased dendricity in LP cells while there was no significant change in DP cells. THC and CBD induced higher levels of reactive oxygen species (ROS) in LP cells while there was no change in the ROS levels in DP cells. In summary, although THC was relatively less cytotoxic as compared to CBD to both LP and DP cells, it exhibited a similar capacity as CBD to stimulate melanin synthesis and export in LP cells which was accompanied by a significant oxidative stress. DP cells were relatively resistant to the effects of both THC and CBD which might implicate the protective effects conferred by melanin in dark-skinned individuals.

The Inhibitory Effect of Curcumin Derivative J147 on Melanogenesis and Melanosome Transport by Facilitating ERK-Mediated MITF Degradation

The therapeutic use of curcumin and chemically modified curcumin (CMC) for suppressing melanogenesis and tyrosinase activity have been recognized. J147 is a modified version of curcumin with superior bioavailability and stability. However, there is no report about the effects of J147 on pigmentation in vitro and in vivo. In our studies, we investigated the hypopigmentary effects of J147 treatment on melanocytes and explored the underlying mechanism. The present studies suggested that J147 suppressed both basal and α-MSH-induced melanogenesis, as well as decreased melanocyte dendricity extension and melanosome transport. J147 played these roles mainly by activating the extracellular signal-regulated protein kinase (ERK) pathway. Once activated, it resulted in MITF degradation and further down-regulated the expression of tyrosinase, TRP-1, TRP-2, Myosin Va, Rab27a and Cdc42, ultimately inhibited melanin synthesis and melanosome transport. Furthermore, the hypopigmentary effects of J147 were demonstrated in vivo in a zebrafish model and UVB-induced hyperpigmentation model in brown guinea pigs. Our findings also suggested that J147 exhibited no cytotoxicity in vitro and in vivo. Taken together, these data confirmed that J147 may prove quite useful as a safer natural skin-whitening agent.

Zebrafish as a new model for rhododendrol-induced leukoderma

Idiopathic leukoderma is a skin disorder characterized by patchy loss of skin pigmentation due to melanocyte dysfunction or deficiency. Rhododendrol (RD) was approved as a cosmetic ingredient in Japan in 2008. However, it was shown to induce leukoderma in approximately 20,000 customers. The prediction of cytotoxicity, especially to melanocytes in vivo, is required to avoid such adverse effects. Since the use of higher vertebrates is prohibited for medicinal and toxicological assays, we used zebrafish, whose melanocytes were regulated by mechanisms similar to mammals. Zebrafish larvae were treated with RD in breeding water for 3 days, which caused body lightening accompanied by a decrease in the number of melanophores. Interestingly, black particles were found at the bottom of culture dishes, suggesting that the melanophores peeled off from the body. In addition, RT-PCR analysis suggested that the mRNA levels of melanophore-specific genes were significantly low. An increase in the production of reactive oxygen species was found in larvae treated with RD. The treatments of the fish with other phenol compounds, which have been reported to cause leukoderma, also induced depigmentation and melanophore loss. These results suggest that zebrafish larvae could be used for the evaluation of leukoderma caused by chemicals, including RD.

Ibuprofen Increases the Hepatotoxicity of Ethanol through Potentiating Oxidative Stress

Over 30 million prescriptions of NSAIDs (non-steroidal anti-inflammatory drugs) are issued every year. Considering that these drugs are available without a prescription as over the counter (OTC) drugs, their use will be astronomical. With the increasing use of NSAIDs, their adverse effects are drawing attention. Especially, stomach bleeding, kidney toxicity, liver toxicity, and neurological toxicity are reported as common. Ibuprofen, one of the extensively used NSAIDs along with aspirin, can also induce liver toxicity, but few studies are addressing this point. Here we examined the liver toxicity of ibuprofen and investigated whether co-exposure to ethanol can manifest synergistic effects. We employed 2D and 3D cultured human hepatoma cells, HepG2 to examine the synergistic hepatotoxicity of ibuprofen and alcohol concerning cell viability, morphology, and histology of 3D spheroids. As a result, ibuprofen and alcohol provoked synergistic hepatotoxicity against hepatocytes, and their toxicity increased prominently in 3D culture upon extended exposure. Oxidative stress appeared to be the mechanisms underlying the synergistic toxicity of ibuprofen and alcohol as evidenced by increased production of ROS and expression of the endogenous antioxidant system. Collectively, this study has demonstrated that ibuprofen and EtOH can induce synergistic hepatotoxicity, providing a line of evidence for caution against the use of ibuprofen in combination with alcohol.

Skin irritation and inhalation toxicity of biocides evaluated with reconstructed human epidermis and airway models

Biocides are widely used in household products. Humans are exposed to biocides through dermal, inhalational, and oral routes. However, information on the dermal and inhalational toxicity of biocides is limited. We evaluated the effects of biocides on the skin and airways using the reconstructed human epidermis model KeraSkin™ and the airway model SoluAirway™. We determined the irritancy of 11 commonly used biocides (1,2-benzisothiazol-3(2H)-one [BIT], 2-phenoxyethanol [PE], zinc pyrithione, 2-bromo-2-nitropropane-1,3-diol, 3-iodoprop-2-ynyl N-butylcarbamate [IPBC], 2-octyl-1,2-thiazol-3-one, 2,2-dibromo-2-cyanoacetamide, 4-chloro-3-methylphenol [CC], 2-phenylphenol, deltamethrin, and 4,5-dichloro-2-octyl-1,2-thiazol-3-one) in the KeraSkin™ and SoluAirway™ by viability and histological examinations. BIT and CC were found to cause skin irritation at the approved concentrations or at the concentration close to approved limit while the others were non-irritants within the approved concentration. These results were confirmed via histology, wherein skin irritants induced erosion, vacuolation, and necrosis of the tissue. In the SoluAirway™, most of the biocides decreased cell viability even within the approved limits, except for PE, IPBC, and deltamethrin, suggesting that the airway may be more vulnerable to biocides than the skin. Taken together, our result indicates that some biocides can induce toxicity in skin and airway. Further studies on the dermal and inhalational toxicity of biocides are warranted.

Antaroide, a Novel Natural Nine-Membered Macrolide, Inhibits Melanin Biosynthesis in B16F10 Murine Melanoma Cells

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). The chemical structure was established through the interpretation of MS, UV, and NMR spectroscopic data. Antaroide is a nine-membered macrolide with lactone and lactam moieties. To investigate its applicability in skin whitening cosmetics, its anti-melanogenic activity in B16F10 murine melanoma cells was examined. As a result, antaroide displayed strong inhibitory activities against melanin synthesis and also attenuated the dendrite formation induced by the α-melanocyte stimulating hormone (α-MSH). Antaroide suppressed the mRNA expression of the melanogenic enzymes such as tyrosinase, TRP-1 and TRP-2. This suggests that it may serve as a transcriptional regulator of melanogenesis. Collectively, the discovery of this novel natural nine-membered macrolide and its anti-melanogenic activity could give new insights for the development of skin whitening agents.

Acremonidin E produced by Penicillium sp. SNF123, a fungal endophyte of Panax ginseng, has antimelanogenic activities

Background

Ginseng extracts and ginseng-fermented products are widely used as functional cosmetic ingredients for their whitening and antiwrinkle effects. Recently, increasing attention has been given to bioactive metabolites isolated from endophytic fungi. However, little is known about the bioactive metabolites of the fungi associated with Panax ginseng Meyer.

Methods

An endophytic fungus, Penicillium sp. SNF123 was isolated from the root of P. ginseng, from which acremonidin E was purified. Acremonidin E was tested on melanin synthesis in the murine melanoma cell line B16F10, in the human melanoma cell line MNT-1, and in a pigmented 3D-human skin model, Melanoderm.

Results

Acremonidin E reduced melanogenesis in α-melanocyte-stimulating hormone (α-MSH)-stimulated B16F10 cells with minimal cytotoxicity. qRT–PCR analysis demonstrated that acremonidin E downregulated melanogenic genes, including tyrosinase and tyrosinase-related protein 1 (TRP-1), while their enzymatic activities were unaffected. The antimelanogenic effects of acremonidin E were further confirmed in MNT-1 and a pigmented 3D human epidermal skin model, Melanoderm. Immunohistological examination of the Melanoderm further confirmed the regression of both melanin synthesis and melanocyte activation in the treated tissue.

Conclusion

This study demonstrates that acremonidin E, a bioactive metabolite derived from a fungal endophyte of P. ginseng, can inhibit melanin synthesis by downregulating tyrosinase, illuminating the potential utility of microorganisms associated with P. ginseng for cosmetic ingredients.