Photoaging of the skin

Selenium chelating collagen peptides as tyrosinase inhibitor: Structure characterization and inhibitory activity

Organoselenium compounds have garnered significant attention as a pivotal tyrosinase inhibitor. In this study, we explore a novel collagen peptides-selenium chelate (CP-Se) for tyrosinase inhibitory activity. The results show that selenium can be mainly bound to N─H and C ═ O bonds on collagen peptides. The IC50 value of tyrosinase inhibitory activity for the CP-Se is 0.47 mg/mL, which demonstrates a significant reduction compared to collagen peptides. Furthermore, the CP-Se exhibits low cytotoxicity, with a survival rate of 93.04 ± 1.48%. The CP-Se effectively curtails melanin production to 55.89 ± 1.12% and intracellular tyrosinase activity to 65.21 ± 2.39%, showcasing its efficacy in mitigating pigmentation processes. Additionally, the CP-Se is found to bind specifically to tyrosinase at the critical residues (Asn 81, His 244, or Arg 268), which are pivotal in facilitating the inhibition of tyrosinase activity. Conclusively, a novel approach to reducing the biological toxicity associated with selenium has been developed, while simultaneously amplifying the tyrosinase inhibitory activity of collagen peptides. This would provide a robust theoretical underpinning for the advancement of novel tyrosinase inhibitors.

Limosilactobacillus fermentum MG5368 and Lactiplantibacillus plantarum MG989 Regulates Skin Health in UVB-Induced HaCaT Cells and Hairless Mice Model

BACKGROUND

Photoaging, induced by chronic ultraviolet B (UVB) exposure, results in the degradation of extracellular matrix (ECM) components, leading to skin roughness, wrinkle formation, and reduced elasticity. Recent studies have explored probiotics as potential inhibitors of extrinsic aging, primarily through mechanisms that protect the skin barrier and reduce collagen breakdown.

METHODS

This study investigates the anti-photoaging effects of Limosilactobacillus fermentum MG5368 (L. fermentum MG5368) and Lactiplantibacillus plantarum MG989 (L. plantarum MG989) in UVB-exposed keratinocytes and an SKH-1 hairless mice model.

RESULTS

Both strains demonstrated significant efficacy in preserving collagen through the inhibition of activating protein-1 (AP-1) and reducing the expression of matrix metalloproteinase (MMP)-1 and MMP-3. Additionally, both strains restored COL1A1 protein expressions, thereby enhancing collagen synthesis and ECM stability. Enhanced skin elasticity was observed, attributed to restored levels of hyaluronic acid and hyaluronan synthase 2 (HAS2) protein expressions.

CONCLUSIONS

These findings suggest that L. fermentum MG5368 and L. plantarum MG989 may serve as promising probiotic-based agents for anti-photoaging applications.

The Characteristics and Inheriting Pattern of Skin Aging in Chinese Women: An Intergenerational Study of Mothers and Daughters

Introduction

The aging of the skin, which is affected by both external and internal causes, can reflect the external age and the internal health status. While the aging characteristics differ across ethnic groups, the specific changes in skin aging within the Chinese population have been underexplored. Moreover, investigating the similarity of aging skin characteristics between parent-offspring pairs remains uncharted territory. This study aims to fill these gaps by examining the skin aging features of Chinese women and assessing the similarity in aging skin characteristics between mother-daughter pairs.

Methods

A total of 40 mother-daughter pairs were recruited and analyzed. The perceived ages of the participants were evaluated, and their aging skin traits were systematically graded. Statistical methods were employed to discern the trends of the aging skin characteristics. By introducing a novel similarity parameter, we compared whether various skin aging characteristics have similar patterns between mothers and daughters.

Results

Our findings indicate that age 50 represents a pivotal point in skin aging. Beyond this age, the increase in rhytides and laxity scores accelerated noticeably, whereas the escalation in dyschromia scores became less marked. By introducing similar parameters between mother-daughter pairs and the radar map, we discovered that the skin aging characteristics are remarkably consistent between mother-daughter pairs.

Conclusion

Understanding the main aging skin characteristics of different age groups can allow caregivers to devise treatments for preventing skin aging in women of various ages. The mother's skin aging trend is also significant for the daughter's skin aging prevention.

Skin Rejuvenation Efficacy and Safety Evaluation of Kaempferia parviflora Standardized Extract (BG100) in Human 3D Skin Models and Clinical Trial

Polymethoxyflavones from Kaempferia parviflora rhizomes have been shown to effectively combat aging in skin cells and tissues by inhibiting senescence, reducing oxidative stress, and enhancing skin structure and function. This study assessed the anti-aging effects and safety of standardized K. parviflora extract (BG100), enriched with polymethoxyflavones including 5,7-dimethoxyflavone, 5,7,4'-trimethoxyflavone, 3,5,7,3',4'-pentamethoxyflavone, 3,5,7-trimethoxyflavone, and 3,5,7,4'-tetramethoxyflavone. We evaluated BG100's impact on skin rejuvenation and antioxidant properties using photoaged human 3D full-thickness skin models. The potential for skin irritation and sensitization was also assessed through studies on reconstructed human epidermis and clinical trials. Additionally, in vitro genotoxicity testing was performed following OECD guidelines. Results indicate that BG100 promotes collagen and hyaluronic acid production, reduces oxidative stress, and minimizes DNA damage in photoaged full-thickness 3D skin models. Furthermore, it exhibited non-irritating and non-sensitizing properties, as supported by tests on reconstructed human epidermis and clinical settings. BG100 also passed in vitro genotoxicity tests, adhering to OECD guidelines. These results underscore BG100's potential as a highly effective and safe, natural anti-aging agent, suitable for inclusion in cosmeceutical and nutraceutical products aimed at promoting skin rejuvenation.

Liquid collagen from freshwater fish skin ameliorates hydration, roughness and elasticity in photo-aged skin: a randomized, controlled, clinical study

BACKGROUND/OBJECTIVES

Collagen is commonly used in diverse forms as a functional component in skincare products. On the other hand, the effects of collagen on human skin are controversial. Dietary collagen hydrolysates from freshwater Pangasius hypophthalmus fish skin ameliorated photo-aged skin of hairless mice. This study conducted a randomized, double-blind, placebo-controlled clinical trial to determine if liquid fish collagen (Collagen-Tripep20™, Tripep20) as a drink strengthens skin health and quality.

SUBJECTS/METHODS

In this clinical trial, 85 subjects aged 35-60 yrs were diagnosed with photo-aged skin. Eighty-five subjects were randomized to receive either Tripep20 (n = 44) or placebo (n = 41). Seventy-eight subjects fully participating for a 12-week period consumed 1,000 mg of Tripep20 (n = 41) or placebo (n = 37) in a 50-mL bottle as a daily drink. The intend-to-treat and per-protocol populations were 85 and 78, respectively. Skin hydration, wrinkles, and elasticity were assessed at 0 (baseline), 6, and 12 weeks during the study period.

RESULTS

Skin hydration in the Tripep20 group was significantly higher from 6 weeks (P < 0.001) than the baseline. After 12 weeks, the Crow's-feet visual score and skin roughness (Ra, Rq, and Rmax) were significantly improved in the Tripep20 group than in the placebo group (P < 0.05). Consuming liquid collagen Tripep20 greatly enhanced skin elasticity (Gross R2, Net R5, and Biological elasticity R7) in 6 weeks compared to the placebo group. The Tripep20 group showed a significant increase in skin elasticity from the baseline after 6 and 12 weeks (P < 0.001). Neither abnormal symptoms nor adverse events were encountered during the study period in subjects ingesting Tripep20 or placebo. The changes in parameters related to hematology and clinical chemistry were within the normal ranges.

CONCLUSION

Oral consumption of liquid collagen Tripep20 was safe and well-tolerated. The results of this study show that freshwater fish-derived liquid collagen Tripep20 can be used as a healthy functional food ingredient to improve skin moisturizing, anti-wrinkling, and elasticity in an aging population.

A decrease of mitochondrial ubiquitin ligase increases the secretion of matrix metalloproteinase-1 by dermal fibroblasts through the induction of ER stress

BACKGROUND

We previously reported that the level of mitochondrial ubiquitin ligase (MITOL) protein in fibroblasts was decreased by UVA and that the knock-down (KD) of MITOL increased the secretion of matrix metalloprotease-1 (MMP-1) by fibroblasts. A recent study reported that MITOL suppresses endoplasmic reticulum (ER) stress by stabilizing the interaction between ER and mitochondria (MT) through the ubiquitination of mitofusin 2. These facts suggest that a decrease of MITOL would increase the secretion of MMP-1 through ER stress, but the detailed mechanism of that process in dermal fibroblasts remains unclear. Thus, this study was conducted to clarify the involvement of ER stress in the oversecretion of MMP-1 induced by the decreased MT quality caused by MITOL-KD.

METHODS

MITOL-KD normal human dermal fibroblast (NHDFs) were prepared by treating them with MITOL-small interfering RNA, after which their MMP-1 protein levels were measured. ER stress in NHDFs was evaluated by measuring the mRNA levels of spliced X-box binding protein 1 (sXBP1) and the protein levels of inositol-requiring enzyme 1α (IRE1α).

RESULTS

MITOL-KD NHDFs enhanced the secretion of MMP-1 via interleukin-6 (IL-6) elicited by the activation of nuclear factor-kappa B (NF-κB). The secretion of MMP-1 could be abrogated by a neutralizing IL-6 antibody and by JSH23, which is an inhibitor of NF-κB activation. Furthermore, MITOL-KD NHDFs as well as UVA-irradiated NHDFs showed increased ER stress levels. In addition, tunicamycin, which is an inducer of ER stress, also increased MMP-1 secretion.

CONCLUSION

These results suggested that the decrease of MITOL caused the oversecretion of MMP-1 via NF-κB-IL-6 signaling through the activation of ER stress in fibroblasts.

Protective effect of Schizonepeta tenuifolia Briq. ethanolic extract against UVB-induced skin aging and photodamage in hairless mice

The purpose of this study was to illuminate the mechanism by which Schizonepeta tenuifolia Briq. (ST) ethanolic extract prevents skin photoaging in HR-1 hairless mice (HR-1). The ST ethanolic extract alleviated wrinkle formation, epidermal skin thickness, and collagen degradation in skin tissues of ultraviolet B (UVB)-irradiated HR-1 mice. Expression of matrix metalloproteinases (a wrinkle-related marker) was reduced, and tissue inhibitor of metalloproteinase 1 expression was upregulated following application of ST ethanolic extract. Furthermore, skin dehydration and levels of hyaluronidase-1 and -2 (enzymes that break hyaluronic acid) were decreased. Moreover, protein expression of hyaluronan synthases (markers of skin hydration) and hyaluronic acid levels increased following ST ethanolic extract treatment in UVB-induced photoaging HR-1 mice. In addition, the phosphorylation of mitogen-activated protein kinases (MAPKs), including p38, extracellular signal-regulated kinase, and Jun N-terminal kinase was suppressed, and expression of nuclear factor-kappa was reduced. Treatment with ST ethanolic extract also reduced advanced glycation end product (AGE) accumulation and expression of the receptor for AGE (RAGE) in skin tissue. These results suggest that ST ethanolic extract moderates skin damage caused by UVB irradiation via regulating the expression of wrinkle- and hydration-related proteins, MAPKs, and RAGE.

Photoprotective Efficacy of the Association of Rosmarinic Acid 0.1% with Ethylhexyl Methoxycinnamate and Avobenzone

Innovative prototype sunscreens with reduced ultraviolet (UV) filters are required to achieve safer, more effective, and more environmentally friendly formulations. Rosmarinic acid (RA) is a phenolic antioxidant and potential candidate for multifunctional sunscreens. We used RA (0.1% w/w) in combination with avobenzone (2.5% and 5.0% w/w), a UVA filter, and ethylhexyl methoxycinnamate (10.0% w/w), a UVB filter, to evaluate in vitro sun protection factor (SPF) and critical wavelength, photostability, and the in vivo SPF. RA, in vitro, improved the SPF of F2 (ethylhexyl methoxycinnamate 10.0% w/w + avobenzone 2.5% w/w + RA 0.1% w/w) and F3 (ethylhexyl methoxycinnamate 10.0% w/w + avobenzone 5.0% w/w + RA 0.1% w/w), which also presented broad-spectrum profiles; however, no expressive effects were observed for the critical wavelength (nm). By the in vivo trial, RA showed an increment in the F3 SPF value and maintained the F2 effectiveness, even when avobenzone was at 2.5%. Nonetheless, no increase in photostability was observed. Our findings suggest that incorporating natural molecules with antioxidant activities into sunscreens could decrease the proportion of conventional UV filters in the final product, with the advantage of providing other functional properties. Further investigation of higher RA concentrations, even from other sources, and other UV filter combinations could reveal important data for the development of multifunctional sunscreens.

Effect of A. polygama APEE (Actinidia polygama ethanol extract) or APWE (Actinidia polygama water extract) on wrinkle formation in UVB-irradiated hairless mice

BACKGROUND

Actinidia polygama (silver vine) is considered a medical plant which has been used in oriental medicine. It has been used for the treatment of pain, gout, rheumatoid arthritis, and inflammation. Few studies reported on the effect of Actinidia polygama (silver vine) on skin photoaging.

OBJECTIVE

To evaluate the anti-photoaging effect of the ethanol and water extracts of A. polygama (APEE and APWE, respectively) in UVB-irradiated hairless mice.

METHODS

SKH-1 hairless mice were exposed to UVB irradiation (30-60 mJ/cm² ), following orally APEE or APWE oral administration for 10 weeks. We examined the effect on winkle improvement by a measuring Fullscope, PRIMOS, Craniometer, and Cutometer. Furthermore, we analyzed histological changes in mouse dorsal skin through hematoxylin and eosin (H&E) and Masson's trichrome (MT) staining. The expression of matrix metalloproteinase (1, 3, and 9) was analyzed by immunoblotting.

RESULTS

Oral administration of APEE or APWE at 100 or 200 mg/kg in UVB-irradiated mice alleviated the symptoms of skin aging, such as wrinkling, epidermal hyperplasia, and water loss. In addition, the APEE or APWE oral administration increased skin elasticity by enhancing the production of type I collagen, elastin, and hyaluronic acid synthase and downregulating matrix metalloproteinase (1, 3, and 9) expression.

CONCLUSION

Based on results for our study, APEE or APWE could protect the UVB-mediated skin wrinkle and is new target for the developing anti-wrinkle cosmetics.

Anti-skin Aging Activities of Sideritis scardica and 3 Flavonoids With an Uncommon 8-Hydroxyl Moiety

The skin plays various crucial biological functions and gradually degenerates due to the process of skin aging. Hence, the development of new ingredients for delaying or even reversing skin aging is an essential subject that needs to be addressed. Our screening effort for anti-skin aging ingredients has led to the discovery that Sideritis scardica extract (SSE) possesses collagenase inhibition, advanced glycation end product (AGE) formation inhibition, antioxidative, and antiallergic activities, as well as ultraviolet B (UVB)-induced matrix metalloproteinase-1 (MMP-1) expression inhibition activity. However, the effect of S. scardica, commonly known as a mountain herb, on skin aging is unknown and needs additional study. Further studies on SSE have led to the isolation of 3 flavonoids with an uncommon 8-hydroxyl moiety, isoscutellarein (1), 4′- O-methylhypolaetin (2), and 4′- O-methylisoscutellarein (3). Biological evaluations also revealed that 1-3 possess SSE collagenase inhibition, AGE formation inhibition, antioxidative, and antiallergic activities, while 3 was identified to possess SSE UVB-induced MMP-1 expression inhibition activity. Moreover, the AGE formation inhibition activity and antiallergic activity of 1-3 were speculated to be derived from their antioxidative activity, while direct inhibition of the collagenase enzyme led to their observed collagenase inhibition activity. Regarding the inhibition activity of 1-3 on UVB-induced MMP-1 expression, further studies are necessary to reveal their possible mechanism of action. Collectively, the biological activities of SSE and the isolated flavonoids 1-3 highlight the potential of S. scardica to be further developed as an agent to delay or reverse skin aging.

Anti-Photoaging Effect of Hydrolysates from Pacific Whiting Skin via MAPK/AP-1, NF-κB, TGF-β/Smad, and Nrf-2/HO-1 Signaling Pathway in UVB-Induced Human Dermal Fibroblasts

Chronic exposure to ultraviolet (UV) light promotes the breakdown of collagen in the skin and disrupts the extracellular matrix (ECM) structure, leading to skin wrinkling. Pacific whiting (Merluccius productus) is a fish abundant on the Pacific coast. In the current study, we investigated the anti-wrinkle effect of hydrolysate from Pacific whiting skin gelatin (PWG) in UVB-irradiated human dermal fibroblasts and the molecular mechanisms involved. PWG effectively restored type 1 procollagen synthesis reduced by UVB-irradiation. Also, we found that PWG inhibited collagen degradation by inhibiting MMP1 expression. Furthermore, PWG decreased cytokines TNF-α, IL-6, and IL-1β associated with inflammatory responses and increased antioxidant enzymes, HO-1, SOD, GPx, CAT, and GSH content, a defense system against oxidative stress. In terms of molecular mechanisms, PWG increased collagen synthesis through activating the transforming growth factor β (TGF-β)/Smad pathway and decreased collagen degradation through inhibiting the mitogen-activated protein kinases/activator protein 1 (MAPK/AP-1) pathway. It also suppressed the inflammatory response through suppressing the nuclear factor-κB (NF-κB) pathway and increased antioxidant enzyme activity through activating the nuclear factor erythroid 2/heme oxygenase 1 (Nrf-2/HO-1) pathway. These multi-target mechanisms suggest that PWG may serve as an effective anti-photoaging material.

Facial Skin Revitalization with Cohesive Polydensified Matrix-HA20G: Results from a Randomized Multicenter Clinical Study

Background:

There is a growing interest in the application of hyaluronic acid (HA) derivatives in skin quality improvement. The aim of this study was to confirm safety and effectiveness of cohesive polydensified matrix-hyaluronic acid + glycerol (CPM-HA20G; Belotero Revive) in revitalization of early-onset photodamaged facial skin.

Methods:

A total of 159 subjects with early signs of facial photodamaged skin were randomized in a 2:1 ratio to multiple- or single-dose treatment with CPMHA20G. Effectiveness assessments included biophysical measurements of skin hydration; elasticity, firmness, and roughness; investigator- and subject-assessed Global Aesthetic Improvement Scales; and FACE-Q Skin Changes and Treatment Satisfaction questionnaires.

Results:

In both treatment groups, skin hydration improved from baseline to all follow-up visits in subjects with dry or very dry skin. This improvement was significant at week 16 after initial treatment in the multiple-dose group (P = 0.0013). Investigator- and subject-reported outcomes showed that the majority of subjects across all skin hydration types benefited from treatment, with higher satisfaction rates observed in the multiple-dose group. According to investigator-assessed Global Aesthetic Improvement Scale, 90.7% of subjects at week 12 in the multiple-dose and 74.6% of subjects at week 4 in the single-dose group were rated as at least “improved.” All related treatment-emergent adverse events were transient, expected injection-site reactions of mild to moderate intensity.

Conclusions:

Effectiveness of CPM-HA20G for skin hydration in subjects with dry or very dry skin was demonstrated up to 9 months after last injection. Overall, CPM-HA20G demonstrated effective and safe use in facial skin revitalization among subjects with early-onset photodamaged skin.

Vaccinium myrtillus L. extract associated with octocrylene, bisoctrizole and titanium dioxide: in vitro and in vivo tests to evaluate safety and efficacy

OBJECTIVE

The harmful effects induced by ultraviolet exposition and the significant increment in skin cancer diagnosis confirm the necessity to develop effective and safe sunscreens. Limited efficacy and cutaneous adverse reactions of traditional formulations drove the incorporation of natural extracts into multifunctional sunscreens. Vaccinium myrtillus L. extract (VME), that contains anthocyanins and flavonoids, is a potential candidate for such systems.

METHODS

Considering that, we performed in vitro and in vivo tests to evaluate the sun protection factor (SPF), photostability and safety of sunscreen samples containing VME.

RESULTS

As main results, the SPF was reduced in both in vitro and in vivo evaluation in the presence of VME, nonetheless, the samples were photostable and safe.

CONCLUSION

Further investigation is required to better understand the unexpected effects of VME over photoprotection, decreasing the SPF value. As a conclusion, even with interesting findings, we highlight the importance of case-by-case investigations to develop multifunctional bioactive sunscreens.

A new product of multi-plant extracts improved skin photoaging: An oral intake in vivo study

BACKGROUND

Besides the topical application of cosmetics, nutraceuticals represent a promising strategy for preventing skin photoaging and skin cancers.

METHODS

To determine the effect of a new multi-plant extracts product containing Cucumis melo extract, acerola extract, olive fruit, aloe vera gel, grape seed extract, and lycopene, a randomized, placebo-controlled, double-blind clinical trial and an ultraviolet (UV)-induced murine photoaging model were deployed. 55 healthy subjects aged 45-60 were enrolled and randomized to take the product or placebo orally for 12 weeks. Skin aging and whitening indexes were measured with non-invasive techniques. 90 Balb/c mice aged 7-8 weeks were randomly divided into six groups: normal, UV, UV+vehicle, UV+different doses of the product (0.500 g/kg.BW, 0.250 g/kg.BW, 0.125 g/kg.BW, respectively). Except the normal group, mid-dorsal regions were irradiated with UVA+UVB for 8 weeks. Factors of oxidative stress, tyrosinase, and histological analysis of the mid-dorsal skin were determined.

RESULTS

In the clinical trial, the TEWL, hydration, sebum, elasticity, and the L*, a*, melanin index change from baseline, ITA° were significantly improved in the experiment group. In the animal experiment, compared to the UV+vehicle group, UV+high dose group showed significantly lower malondialdehyde (MDA) and tyrosinase, but higher superoxide dismutase (SOD), total antioxidant capacity (T-AOC), and glutathione peroxidase (GSH-Px). The UV+moderate dose group showed significant improvement of MDA and GSH-Px, and the UV+low dose group only showed improvement of GSH-Px. Histological photoaging manifestations were attenuated in the UV+high and moderate dose groups.

CONCLUSIONS

The multi-plant extracts product improved skin photoaging possibly via antioxidant and anti-tyrosinase ways.

Antiphotoaging properties of Zingiber montanum essential oil isolated by solvent-free microwave extraction against ultraviolet B-irradiated human dermal fibroblasts

Maintaining youthful skin from photoaging with natural products, including essential oils, is a vital strategy that has piqued the interest of researchers in the pharmaceutical and cosmetic industries. This research aimed to investigate the protective properties of Zingiber montanum (J. Koenig) Link ex A. Dietr. essential oil against ultraviolet B (UVB)-induced skin damage and photoaging in normal human dermal fibroblast (HDFn) cells. The essential oil was extracted from fresh plant rhizomes using solvent-free microwave extraction. Its antiphotoaging properties in HDFn cells were investigated using reactive oxygen species (ROS)-scavenging, wound healing, matrix metalloproteinases (MMP-1, MMP-3, and MMP-9) expression, procollagen synthesis, and elastase and tyrosinase inhibitory assays. The results showed that the test oil exhibited no significant toxicity in HDFn at concentrations up to 10 mg/mL, with cell viability exceeding 90%. Following UVB irradiation at 30 mJ/cm², Z. montanum oil demonstrated time and concentration-dependent ROS radical scavenging capabilities. In a cell migration assay, the essential oil demonstrated wound-healing properties. Z. montanum oil suppressed the expression of MMPs and enhanced the synthesis of type I procollagen at a concentration of 0.1-1 mg/mL. In addition, 0.1-1 mg/mL Z. montanum oil inhibited elastase activity in a concentration-dependent manner but did not affect tyrosinase activity. From these findings, the essential oil of Z. montanum could have potential applications in developing cosmeceutical products to prevent skin photoaging.

Mitochondrial Secrets of Youthfulness

SUMMARY

The genetic basis of youthfulness is poorly understood. The aging of skin depends on both intrinsic factors and extrinsic factors. Intrinsic factors include personal genetics, and extrinsic factors include environmental exposure to solar radiation and pollution. We recently reported the critical role of the mitochondria in skin aging phenotypes: wrinkle formation, hair graying, hair loss, and uneven skin pigmentation. This article focuses on molecular mechanisms, specifically mitochondrial mechanisms underlying skin aging. This contribution describes the development of an mitochondrial DNA depleter-repleter mouse model and its usefulness in developing strategies and identifying potential agents that can either prevent, slow, or mitigate skin aging, lentigines, and hair loss. The ongoing research efforts include the transplantation of young mitochondria to rejuvenate aging skin and hair to provide youthfulness in humans.

Evaluating the Antioxidants, Whitening and Antiaging Properties of Rice Protein Hydrolysates

Plant-derived protein hydrolysates have potential applications in nutrition. Rice protein hydrolysates (RPHs), an excellent source of proteins, have attracted attention for the development of cosmeceuticals. However, few studies have reported the potential application of RPH in analysis, and this study examined their antioxidant activities and the inhibitory activities of skin aging enzymes. The results indicated that the total phenolic and flavonoid concentrations were 2.06 ± 0.13 mg gallic acid equivalent/g RPHs and 25.96 ± 0.52 µg quercetin equivalent/g RPHs, respectively. RPHs demonstrated dose-dependent activity for scavenging free radicals from 1,1-diphenyl-2-picrylhydrazyl [half-maximal inhibitory concentration (IC50) = 42.58 ± 2.1 mg/g RPHs] and 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) (IC50 = 2.11 ± 0.88 mg/g RPHs), dose-dependent reduction capacity (6.95 ± 1.40 mg vitamin C equivalent/g RPHs) and oxygen radical absorbance capacity (473 µmol Trolox equivalent/g RPHs). The concentrations of the RPH solution required to achieve 50% inhibition of hyaluronidase and tyrosinase activities were determined to be 8.91 and 107.6 mg/mL, respectively. This study demonstrated that RPHs have antioxidant, antihyaluronidase, and antityrosinase activities for future cosmetic applications.

Inhibition of Solar UV-Induced Matrix Metalloproteinase (MMP)-1 Expression by Non-Enzymatic Softening Cherry Blossom (Prunus yedoensis) Extract

Cherry blossom (Prunus yedoensis) petals are used as ingredients in many cosmetics. However, despite their use in numerous products, the exact function of cherry blossom petals in cosmetics is unclear. Therefore, we need evidence-based studies to support the labeling claims that are made in cherry blossom products in the cosmetics industry. We investigated the skin anti-aging potential of non-enzymatic softening cherry blossom extract (NES-CBE) in this study. The extract desalinated, to improve its quality such that it can be used as a functional material for the skin. The anti-wrinkle effect of NES-CBE was investigated on human keratinocytes (HaCaT cells) under solar UV (sUV) light exposure. We found that NES-CBE reduced the sUV-induced matrix metalloproteinase (MMP)-1 expression and modulated the transactivation of the activator protein (AP)-1. Furthermore, NES-CBE suppressed the phosphorylation of MEK1/2 and ERK proteins, indicating its regulation of sUV-induced MAPK signaling. Additionally, we observed NES-CBE reduced MMP-1 protein expression in a human skin equivalent model. Taken together, these results suggest that NES-CBE reduces sUV-induced MMP-1 protein expression through reducing AP-1 transactivation via regulation of the MEK1/2-ERK pathway.

Anti-Photoaging and Potential Skin Health Benefits of Seaweeds

The skin health benefits of seaweeds have been known since time immemorial. They are known as potential renewable sources of bioactive metabolites that have unique structural and functional features compared to their terrestrial counterparts. In addition, to the consciousness of green, eco-friendly, and natural skincare and cosmetics products, their extracts and bioactive compounds such as fucoidan, laminarin, carrageenan, fucoxanthin, and mycosporine like amino acids (MAAs) have proven useful in the skincare and cosmetic industries. These bioactive compounds have shown potential anti-photoaging properties. Furthermore, some of these bioactive compounds have been clinically tested and currently available in the market. In this contribution, the recent studies on anti-photoaging properties of extracts and bioactive compounds derived from seaweeds were described and discussed.

4-Hydroxynonenal Contributes to Fibroblast Senescence in Skin Photoaging Evoked by UV-A Radiation

Solar ultraviolet A (UV-A) radiation promotes a huge variety of damages on connective tissues and dermal fibroblasts, including cellular senescence, a major contributor of skin photoaging. The mechanisms of skin photoaging evoked by UV-A partly involve the generation of reactive oxygen species and lipid peroxidation. We previously reported that 4-hydroxynonenal (HNE), a lipid peroxidation-derived aldehyde, forms adducts on elastin in the skins of UV-A irradiated hairless mice, possibly contributing to actinic elastosis. In the present study, we investigated whether and how HNE promotes fibroblast senescence in skin photoaging. Dermal fibroblasts of skins from UV-A-exposed hairless mice exhibited an increased number of γH2AX foci characteristic of cell senescence, together with an accumulation of HNE adducts partly colocalizing with the cytoskeletal protein vimentin. Murine fibroblasts exposed to UV-A radiation (two cycles of 15 J/cm²), or HNE (30 µM, 4 h), exhibited senescence patterns characterized by an increased γH2AX foci expression, an accumulation of acetylated proteins, and a decreased expression of the sirtuin SIRT1. HNE adducts were detected on vimentin in cultured fibroblasts irradiated by UV-A or incubated with HNE. The HNE scavenger carnosine prevented both vimentin modification and fibroblast senescence evoked by HNE in vitro and in the skins of UV-A-exposed mice. Altogether, these data emphasize the role of HNE and lipid peroxidation-derived aldehydes in fibroblast senescence, and confirm the protective effect of carnosine in skin photoaging.

Antiphotoaging Effect of 3,5-Dicaffeoyl-epi-quinic Acid against UVA-Induced Skin Damage by Protecting Human Dermal Fibroblasts In Vitro

Cutaneous aging is divided into intrinsic and exogenous aging correspondingly contributing to the complex biological phenomenon in skin. Intrinsic aging is also termed chronological aging, which is the accumulation of inevitable changes over time and is largely genetically determined. Superimposed on this intrinsic process, exogenous aging is associated with environmental exposure, mainly to ultraviolet (UV) radiation and more commonly termed as photoaging. UV-induced skin aging induces increased expression of matrix metalloproteinases (MMPs) which in turn causes the collagen degradation. Therefore, MMP inhibitors of natural origin are regarded as a primary approach to prevent or treat photoaging. This study investigated the effects of 3,5-dicaffeoyl-epi-quinic acid (DEQA) on photoaging and elucidated its molecular mechanisms in UVA-irradiated human dermal fibroblasts (HDFs). The results show that treatment with DEQA decreases MMP-1 production and increases type I collagen production in UVA-damaged HDFs. In addition, treatment of UVA-irradiated HDFs with DEQA downregulates MMP-1, MMP-3 and MMP-9 expression via blocking MAPK-cascade-regulated AP-1 transcriptional activity in UVA-irradiated HDFs. Furthermore, DEQA relieves the UVA-mediated suppression of type I procollagen and collagen expression through stimulating TGF-β/Smad signaling, leading to activation of the Smad 2/3 and Smad 4 nuclear translocation. These results suggest that DEQA could be a potential cosmetic agent for prevention and treatment of skin photoaging.

Microemulsion composed of combination of skin beneficial oils as vehicle: Development of resveratrol-loaded microemulsion based formulations for skin care applications

Microemulsion can be a potential delivery vehicle to deliver skin care actives to deep skin layer for chronic skin care benefits. On top of skin care active, microemulsion vehicle composed of multiple skin beneficial oils can deliver additional skin care efficacies. In this study, microemulsions were developed using combinations of two skin beneficial oils, tea tree oil and medium chain triglyceride instead of single oil. For that, pseudo ternary phase diagrams were constructed on these oil combinations at different ratios of surfactant/co-surfactants. Ratio of oils and surfactant/co-surfactant combinations exhibited significant impact on the microemulsion region. A few compositions were selected from the single phase microemulsion regions of these phase diagrams for the preparation of resveratrol-loaded microemulsion and microemulsion gel formulations. The particle size of the resveratrol-loaded microemulsions were <50 nm. Cryogenic scanning electron microscope image clearly showed nano-droplets dispersed in continuous phase. Both physical and chemical stability of the formulations varied depending on their compositions, such as surfactant/co-surfactant combination and % total oil. The presence of chelating agent and anti-oxidant was also crucial to stabilize the formulations. The selected formulations demonstrated good physicochemical stability at 5 °C, 25 °C, and 40 °C/75 % RH (relative humidity) stability conditions. The results further showed that the % total oil and surfactant phase composition had huge influence on resveratrol release and skin permeation patterns from the microemulsion gels. In vitro skin permeation result indicated that the microemulsion gels can help resveratrol penetration into deep skin layer. Therefore, the developed resveratrol-loaded microemulsion gels can be utilized as skin care product with multiple skin care benefits.

A Randomized Study to Determine the Sun Protection Factor of Natural Pterostilbene from Pterocarpus Marsupium

Ultraviolet (UV) rays and its harmful effects have always been a concern to skin health. Sunscreen and sunblock prevent the harmful effects of UV radiation on the skin. Sun Protection Factor (SPF) is an indication of the sun-protective capacity of an ingredient. There is an ever increasing interest in the cosmetic industry for developing novel functional ingredients from natural sources. The purpose of this study was to determine in-vitro and in vivo SPF of natural 90% pterostilbene extracted from the dried heartwood of Pterocarpus marsupium (Indian Kino). The SPF of purified pterostilbene and a formulation containing 0.4% pterostilbene was determined In Vitro using a UV spectrophotometer. Pterostilbene had an SPF of 21.73 ± 0.06, while the cream formulation had an SPF of 8.84 ± 0.01. The in vivo SPF of the 0.4% pterostilbene cream in humans was found to be 6.2 ± 1.30. Primary skin irritation tests in human subjects showed the formulation was safe and had no irritation potential. Pterostilbene was also found to have significant antioxidant activity as determined by free radical scavenging assays in vitro. These results suggest that natural pterostilbene is an antioxidant and shows SPF value both in-vitro and in the human clinical study and thus could be used as an ingredient in topical sun-protective formulations.

Macroalgae Sargassum cristaefolium Extract Inhibits Proinflammatory Cytokine Expression in BALB/C Mice

Ultraviolet radiation (UVR) which could induce skin damage and skin disease is a growing concern due to the increase in global warming. Brown macroalgae Sargassum cristaefolium has been recognized to exhibit UV protective activities. However, the mechanism of its photoprotective activity remains unclear. The purpose of this study is to investigate the potential mechanism of S. cristaefolium's photoprotective activity against UV radiation. Phytochemical analyses revealed valuable bioactive compounds in SCE, such as fucoxanthin which is widely known as an anti-inflammatory carotenoid. Treatment with SCE before UV-A radiation show reduced levels of wrinkles and desquamation. Interestingly, SCE treatment induces the skin healing process after UV radiation. SCE effectively inhibited proinflammatory TNF-α and IL-6 expression while increasing IL-10 production in the BALB/c mice skin. Current results suggest that SCE potentially protects the skin by attenuation of inflammatory cytokines. In addition, SCE demonstrates promising antibacterial activity (MIC = 1.302 µg/mL) against Staphylococcus aureus. Overall, SCE could be a source of an effective anti-inflammatory agent protecting against UV irradiation-induced skin damages.

Dietary Suberic Acid Protects Against UVB-Induced Skin Photoaging in Hairless Mice

Ultraviolet (UV) radiation is a major cause of skin photoaging, which is mainly characterized by dryness and wrinkle formation. In the current study, we investigated the anti-photoaging effects of dietary suberic acid, a naturally occurring photochemical, using UVB-irradiated hairless mice. Mice were exposed to UVB three times weekly and fed diets containing three different suberic acid concentrations (0.05%, 0.1% and 0.2%) for 10 weeks. It was found that suberic acid inhibited UVB-induced skin dryness, wrinkle formation, and epidermal thickness in hairless mice. In parallel with phenotypic changes, suberic acid attenuated UVB-induced matrix metalloproteinase (MMP) genes (MMP1a, MMP1b, MMP3, and MMP9), while accelerating collagen genes including collagen type I alpha 1 chain (COL1A1), COL1A2, and COL3A1 and hyaluronic acid synthases genes (HAS1, HAS2 and HAS3). We further demonstrated that suberic acid upregulated the molecules involved in the transforming growth factor-β (TGF-β)/SMAD pathway, but downregulated the molecules participating in the mitogen-activated protein kinase (MAPK)/activator protein 1 (AP-1) signaling in UVB-irritated hairless mice. Collectively, we propose that suberic acid may be a promising agent for treating skin photoaging.

Low molecular polypeptide from oyster hydrolysate recovers photoaging in SKH-1 hairless mice

When the human skin is chronically exposed to external stimuli such as ultraviolet (UV) radiation, the skin tissue suffers damage and the structure of the extracellular matrix (ECM) in the skin is disrupted. This eventually causes symptoms such as wrinkles loss of elasticity, skin sagging, and skin cancer. We previously found that hydrolysate extracted from pacific oyster (Crassostrea gigas) is effective in improving wrinkle formation. In this study, we selected a pentapeptide that was expected to have the most wrinkle reduction effect among the various peptides in oyster hydrolysate through preliminary in vitro screening and examined whether the pentapeptide derived from oyster hydrolysate (OHP) is effective in reducing wrinkles in vivo. We investigated the wrinkle-reducing effect of the OHP through 18-week SKH-1 hairless mice model. Our results showed that the OHP reduces wrinkles lengths, depths, and epidermal thickness which were increased by UVB radiation, and restores the amount of collagen. The OHP recovered the activity of antioxidant enzymes and regulated the expression of proinflammatory cytokines. We also found that OHP increases the expression of type I collagen through stimulating the TGFβ/Smad signaling pathway and inhibits the MMPs expression by regulating the MAPK/AP-1 signaling pathway. This study has shown that the OHP plays crucial roles in collagen production and wrinkle reduction in hairless mice and we proved the possibility of the OHP as a component for inhibiting wrinkle formation which was induced by photoaging.

A bioinspired, photostable UV-filter that protects mammalian cells against UV-induced cellular damage

While commercially available suncare products are effective at absorbing ultraviolet (UV)-light, recent studies indicate systemic toxicities associated with many traditional chemical and physical UV-filters. We demonstrate the application of xanthommatin, a biochrome present in arthropods and cephalopods, as an alternative chemical UV-filter that is cytocompatible while maintaining its photostability and photoprotective properties.

Aging in skin of color

Ethnic skin is quickly emerging as the norm in the United States, and as the population becomes more diverse, there is also a projected rise in the number of aging adults. Given the paucity of data regarding aging in ethnic skin, the authors have consolidated available information for this population. Literature examining structural and functional variation of aging in ethnic skin types was primarily found through PubMed and supplemental textbook chapters. Aging is comprised of two synergistic processes, intrinsic or chronologic aging, and extrinsic aging. Caucasian, African American, East Asian, and Hispanic skin each have distinguishing features of aging, but all populations share dyspigmentation, rhytides, and skin laxity. Increased melanin content predisposes skin of color to a greater degree of hyperpigmentation, but skin thickness may protect against the formation of rhytides. Tailored prevention and treatment are also paramount in attaining favorable outcomes for this growing cohort.

Protective skin aging effects of cherry blossom extract (Prunus Yedoensis) on oxidative stress and apoptosis in UVB-irradiated HaCaT cells

Extracts of the cherry blossom plant have been reported to exert various biological effects on human cells. However, no previous investigations have examined the antioxidant and anti-apoptotic effects of these extracts on ultraviolet B (UVB) radiation-induced skin aging. This study explores the underlying mechanisms of the antioxidant and anti-apoptotic effects of cherry blossom extract (CBE) in human keratinocyte (HaCaT) cells. HaCaT cells were treated with CBE at concentrations of 0.5, 1.0, and 2.0% for 24 h and then irradiated with UVB (40 mJ/cm²). CBE effectively and dose-dependently decreased the levels of reactive oxygen species and malondialdehyde, while increasing the activities of superoxide dismutase and glutathione peroxidase. Pretreatment with 1 and 2% CBE attenuated UVB-induced DNA damage by reducing the formation of cyclobutane pyrimidine dimers and 8-hydroxy-20-deoxyguanosine. Furthermore, CBE also prevented UVB-induced apoptosis and significantly downregulated B cell lymphoma 2 (Bcl-2)-associated X, cytochrome-c, and caspase-3 expression, while upregulating Bcl-2 expression. Taken together, these results indicate that CBE protects HaCaT cells from UVB-induced oxidative stress and apoptosis and suggest that CBE could be a potent antioxidant against skin aging.

Anti-photoaging effects of solvent-partitioned fractions from Portulaca oleracea L. on UVB-stressed human keratinocytes

In this study, the anti-photoaging activity of solvent-fractionated extracts from Portulaca oleracea L. was investigated in ultraviolet B-stressed keratinocytes. The results showed that the treatment of the fractions suppressed the generation of intracellular reactive oxygen species (ROS) and activated mRNA and protein expression levels of superoxide dismutase1 (SOD-1) and heme oxygenase1 (HO-1) enzymes via Nrf-2 pathway. The tested fractions down-regulated the expression of matrix metalloproteinases (MMPs) and up-regulated type Ⅰ procollagen production. Among the tested samples, the 85% aq. MeOH fraction was the most effective in suppressing MMPs and type Ⅰ procollagen degradation. Two homoisoflavonoids, portulacanone A (PA) and portulacanon D (PD), were isolated from the 85% aq. MeOH fraction. PA and PD successfully inhibited the secretionof MMP-1 and increased the production of type Ⅰ procollagen in UVB-stressed keratinocytes. Therefore, solvent-partitioned factions from P. oleracea and its active components, PA and PD, were suggested to have beneficial effects against photoaging. PRACTICAL APPLICATIONS: Portulaca oleracea L. is an edible nutrient-rich herb with high amounts of omega-3 and omega-6 fatty acids, ascorbic acid, and dietary minerals. P. oleracea has also been used as a botanical medicine for its potential health benefits such as antioxidant, antibacterial, and antiinflammatory properties. The current study suggested that the extracts from P. oleracea were able to prevent human keratinocytes from UVB-induced stress and damage. Due to its protective abilities, it can be used as an additive in the cosmeceutical industry to produce novel skin protectants. In addition, due to its intracellular antioxidant and MMP inhibitory effects, it can be a valuable source for nutraceutical development. Further studies that characterize the isolated flavonoids may also yield bioactive molecules to be utilized in cosmeceutical and nutraceutical industries as lead compounds. Nevertheless, P. oleracea can serve as a health beneficial addition to topical applications and dietary supplements against UVB-stimulated oxidative stress in skin cells.

Topical treatment with a cathepsin G inhibitor, β-keto-phosphonic acid, blocks ultraviolet irradiation-induced basement membrane damage in hairless mouse skin

BACKGROUND

Ultraviolet light (UV) exposure contributes various effects to skin including damage of the basement membrane. Cathepsin G (CTSG) belongs to serine protease family, and its upregulation is involved in wrinkle formation by chronic UV irradiation. However, the effect of CTSG on the basement membrane damage in skin remains unclear.

PURPOSE

To investigate the effects of topical treatment with a CTSG inhibitor, β-keto-phosphonic acid (KPA), on basement membrane damage in chronically UV-irradiated hairless mouse skin.

METHODS

The dorsal skin of hairless mice was exposed to UV three times per week for 8 weeks. KPA was applied immediately after each session of UV irradiation. The basement membrane components, CTSG expression, and neutrophil infiltration were analyzed by immunofluorescence staining. The basement membrane structures were visualized by transmission electron microscope. CTSG and MMP-13 protein levels were analyzed by Western blotting. Assessment of wrinkle formation was examined using a skin replica assay.

RESULTS

β-keto-phosphonic acid prevented UV irradiation-induced decrease in type VII collagen, laminin 332, and perlecan at the basement membrane zone and prevented UV-induced breakage of lamina densa and UV-induced shortening of hemidesmosome. KPA prevented UV-induced CTSG and MMP-13 expressions in chronically UV-irradiated hairless mice. Increase in neutrophil infiltration by UV irradiation and UV-induced wrinkle formation was also prevented by KPA.

CONCLUSION

Our present study showed the possible involvement of CTSG in UV-induced basement membrane damage in skin through topical treatment with a CTSG inhibitor, KPA. Thus, inhibition of CTSG may be a useful strategy for the prevention of UV-induced basement membrane damage and photoaging.

Blue Light Induces Down-Regulation of Aquaporin 1, 3, and 9 in Human Keratinocytes

The development in digital screen technology has exponentially increased in the last decades, and many of today's electronic devices use light-emitting diode (LED) technology producing very strong blue light (BL) waves. Long-term exposure at LED-BL seems to have an implication in the dehydration of the epidermis, in the alterations of shape and number of the keratinocytes, and in the aging of the skin. Aquaporins (AQPs) are water membrane channels that permeate both water and glycerol and play an important role in the hydration of epidermis, as well as in proliferation and differentiation of keratinocytes. Thus, we have hypothesized that AQPs could be involved in the aging of the skin exposed to LED-BL. Therefore, we have examined the expression of AQPs in human keratinocytes exposed to LED-BL at dose of 45 J/cm², used as an in vitro model to produce the general features of photo aging of the skin. The aim was to verify if LED-BL induces changes of the basal levels of AQPs. The keratinocytes exposure to LED-BL produced an increase of reactive oxygen species (ROS), an activation of 8-hydroxy-2'-deoxyguanosine (8-OHdG), an alteration of proliferating cell nuclear antigen (PCNA), and a down-regulation of AQP1, 3 and 9. These findings are preliminary evidences that may be used as starting points for further investigations about the mechanistic involvement of AQP1, 3, and 9 in LED-BL-induced skin aging.

Protective Effects of Euphrasia officinalis Extract against Ultraviolet B-Induced Photoaging in Normal Human Dermal Fibroblasts

Ultraviolet (UV) radiation induces skin photoaging, which is associated with the elevation of matrix metalloproteinases (MMPs) and the impairment of collagen. The Euphrasia species play a well-known role in the treatment of certain eye disorders through their anti-oxidative and anti-inflammatory activities. However, their protective activity toward UVB-induced damage remains unclear. In the present study, we investigated the protective effect of Euphrasia officinalis (95% ethanol extract) on UVB-irradiated photoaging in normal human dermal fibroblasts (NHDFs). Our results show that Euphrasia officinalis extract exhibited obvious reactive oxygen species (ROS) and 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical scavenging activity, enhanced NHDF cell migration, and reduced UVB-induced apoptosis. The UVB-induced increases in MMP-1 and MMP-3 and decrease in type I procollagen were ameliorated by Euphrasia officinalis treatment, which worked by suppressing the mitogen-activated protein kinase (MAPK) and nuclear transcription factor activator protein 1 (AP-1) signaling pathways. Taken together, our data strongly suggest that Euphrasia officinalis ethanol extract could reduce UVB-induced photoaging by alleviating oxidative stress, proinflammatory activity, and cell apoptosis.

3-O-Glyceryl-2-O-hexyl Ascorbate Suppresses Melanogenesis through Activation of the Autophagy System

The formation of skin pigmentation requires multiple steps, namely the activation of melanocytes, the synthesis of melanin, the transport of melanosomes to the tips of melanocyte dendrites and the transfer of melanosomes from melanocytes to surrounding keratinocytes. Recently, we reported that melanosomes accumulate in melanocytes when melanosome transport is disrupted and that they are then degraded by the autophagy system. In this study, we examined whether 3-O-glyceryl-2-O-hexyl ascorbate (VC-HG) suppresses melanogenesis through the activation of autophagy since VC-HG interferes with melanosome transport through the down-regulated expression of MyosinVa and Kinesin. The results demonstrate that VC-HG-treated B16 cells show an activation of autophagy through an increased expression level of Microtubule-associated protein 1 light chain 3 (LC3)-II and a decreased expression level of p62. Furthermore, the decrease of melanin content elicited by VC-HG was partially abolished by hydroxychloroquine or pepstatin A which are inhibitors of autophagy. Taken together, we conclude that VC-HG suppresses melanogenesis by activating the autophagy system.

Oral Intake of Low-Molecular-Weight Collagen Peptide Improves Hydration, Elasticity, and Wrinkling in Human Skin: A Randomized, Double-Blind, Placebo-Controlled Study

Collagen-peptide supplementation could be an effective remedy to improve hydration, elasticity, and wrinkling in human skin. The aim of this study was to conduct a double-blind, randomized, placebo-controlled trial to clinically evaluate the effect on human skin hydration, wrinkling, and elasticity of Low-molecular-weight Collagen peptide (LMWCP) with a tripetide (Gly-X-Y) content >15% including 3% Gly-Pro-Hyp. Individuals (n = 64) were randomly assigned to receive either placebo or 1000 mg of LMWCP once daily for 12 weeks. Parameters of skin hydration, wrinkling, and elasticity were assessed at baseline and after 6 weeks and 12 weeks. Compared with the placebo group, skin-hydration values were significantly higher in the LMWCP group after 6 weeks and 12 weeks. After 12 weeks in the LMWCP group, visual assessment score and three parameters of skin wrinkling were significantly improved compared with the placebo group. In case of skin elasticity, one parameter out of three was significantly improved in the LMWCP group from the baseline after 12 weeks, while, compared with the placebo group, two parameters out of three in the LMWCP group were higher with significance after 12 weeks. In terms of the safety of LMWCP, none of the subjects presented adverse symptoms related to the test material during the study period. These results suggest that LMWCP can be used as a health functional food ingredient to improve human skin hydration, elasticity, and wrinkling.

An Insight into Ginsenoside Metabolite Compound K as a Potential Tool for Skin Disorder

Ginsenosides are the major bioactive natural compounds derived from Panax ginseng. Several studies report the pharmaceutical benefits of several ginsenosides, including antidementia, antitumor, and anti-inflammatory activity. Biotransformations by gut microbiome contribute to the biological function of these ginsenosides. After ingestion ginsenosides are hydrolyzed to Rg2, Rg3, compound K, and others by human gut flora. Compound K is considered the representative active metabolite after oral administration of ginseng or ginsenosides. Various studies report the diverse biological functions of compound K, such as antitumor, antidiabetic, antiallergic, and anti-inflammatory activity. Recent clinical trial and in vitro studies demonstrate the antiaging activities of ginsenosides in human skin. Ginsenosides have been considered as an important natural dermatological agent. In this review, we will cover the modern tools and techniques to understand biotransformation and delivery of compound K. Also the biological function of compound K on skin disorder and its potential dermatological application will be discussed.

Establishment of Photoaging In Vitro by Repetitive UVA Irradiation: Induction of Characteristic Markers of Senescence and its Prevention by PAPLAL with Potent Catalase Activity

To understand a role of UVA radiation in photoaging of the skin, we established a model of photoaging cells using cultured human dermal fibroblasts. Repeated low-dose UVA radiation for 10 consecutive days induced senescence in fibroblasts, characterized with (1) increased level of senescence-associated β-galactosidase, (2) flattened large cell shape, (3) accumulation of reactive oxygen species, (4) yellowish coloration and (5) expression of p16. These were also observed in chronologically aged fibroblasts (doubling times >20), whereas none of these were detected in young cells (doubling times <10). Collectively, we propose that fibroblasts exposed to repetitive UVA radiation may be a good model of aged cells to study the mechanism of aging and photoaging and further to search for novel agents preventing cellular senescence. In addition, H₂ O₂ was produced in the culture medium by a single low dose of UVA irradiation. Further, PAPLAL, a nanoparticle of platinum and palladium having potent catalase-like activity, significantly delayed the onset of H₂ O₂ -induced cell senescence. The present study strongly indicates that repetitive short-term UVA irradiation induces aging of cells possibly via H₂ O₂ and may be suppressed by potent anti-H₂ O₂ agents.

3-O-Glyceryl-2-O-hexyl ascorbate suppresses melanogenesis by interfering with intracellular melanosome transport and suppressing tyrosinase protein synthesis

BACKGROUND

Ascorbic acid (AsA) has multifunctional benefits on skin beauty, such as the reduction in oxidative stress and the induction of collagen production. Among them, the prevention and improvement of skin pigmentation by AsA is a most important benefit for people. However, it is well known that AsA not only is quite unstable in formulations but it also has a low capability of skin penetration due to its hydrophilic property. In addition, existing water-soluble AsA derivatives that were developed to improve its stability also have low skin penetration.

AIM

To investigate the potential of a newly synthesized amphiphilic derivative of AsA, 3-O-Glyceryl-2-O-hexyl ascorbate (VC-HG), which has an added glyceryl group and a hexyl group, on skin beauty focusing on its skin lightening/whitening effects.

METHODS

DNA microarray analysis and real-time PCR were used to clarify the effects of VC-HG on melanogenesis using B16 mouse melanoma cells. The effects of VC-HG on melanin synthesis, tyrosinase protein levels, and the inhibition of tyrosinase activity were evaluated.

RESULTS

DNA microarray analysis revealed that treatment with VC-HG downregulated the expression of genes encoding tyrosinase and MyosinVa. Further, real-time PCR analysis showed the downregulation of tyrosinase, MyosinVa, Rab27a, and Kinesin mRNAs following VC-HG treatment. In addition, VC-HG caused decreases in tyrosinase protein levels and melanin synthesis.

CONCLUSION

We conclude that VC-HG has an impact on skin lightening/whitening by inhibiting tyrosinase protein synthesis and interfering with intracellular melanosome transport.

Disinfection and healing effects of 222-nm UVC light on methicillin-resistant Staphylococcus aureus infection in mouse wounds

UVC radiation is known to be highly germicidal. However, exposure to 254-nm-UVC light causes DNA lesions such as cyclobutane pyrimidine dimers (CPD) in human cells, and can induce skin cancer after long-term repeated exposures. It has been reported that short wavelength UVC is absorbed by proteins in the membrane and cytosol, and fails to reach the nucleus of human cells. Hence, irradiation with 222-nm UVC might be an optimum combination of effective disinfection and biological safety to human cells. In this study, the biological effectiveness of 222-nm UVC was investigated using a mouse model of a skin wound infected with methicillin-resistant Staphylococcus aureus (MRSA). Irradiation with 222-nm UVC significantly reduced bacterial numbers on the skin surface compared with non-irradiated skin. Bacterial counts in wounds evaluated on days 3, 5, 8 and 12 after irradiation demonstrated that the bactericidal effect of 222-nm UVC was equal to or more effective than 254-nm UVC. Histological analysis revealed that migration of keratinocytes which is essential for the wound healing process was impaired in wounds irradiated with 254-nm UVC, but was unaffected in 222-nm UVC irradiated wounds. No CPD-expressing cells were detected in either epidermis or dermis of wounds irradiated with 222-nm UVC, whereas CPD-expressing cells were found in both epidermis and dermis irradiation with 254-nm UVC. These results suggest that 222-nm UVC light may be a safe and effective way to reduce the rate of surgical site and other wound infections.

Mycosporine-Like Amino Acids: Potential Health and Beauty Ingredients

Human skin is constantly exposed to damaging ultraviolet radiation (UVR), which induces a number of acute and chronic disorders. To reduce the risk of UV-induced skin injury, people apply an additional external protection in the form of cosmetic products containing sunscreens. Nowadays, because of the use of some chemical filters raises a lot of controversies, research focuses on exploring novel, fully safe and highly efficient natural UV-absorbing compounds that could be used as active ingredients in sun care products. A promising alternative is the application of multifunctional mycosporine-like amino acids (MAAs), which can effectively compete with commercially available filters. Here, we outline a complete characterization of these compounds and discuss their enormous biotechnological potential with special emphasis on their use as sunscreens, activators of cells proliferation, anti-cancer agents, anti-photoaging molecules, stimulators of skin renewal, and functional ingredients of UV-protective biomaterials.

Association of Diet With Skin Histological Features in UV-B-Exposed Mice

Importance

Long-term exposure to solar radiation produces deleterious photoaging of the skin. It is not known if diet can influence skin photoaging.

Objectives

To study the influence of a calorie-restricted diet and an obesity diet in mice exposed to long-term UV-B irradiation to assess if there is an association between diet and histopathological response to UV-B irradiation.

Design, Setting, and Participants

In this animal model study in an academic setting, the dorsal skin of SKH1 hairless mice receiving normal, calorie-restricted, and obesity diets was exposed to UV-B irradiation 3 times a week for 10 weeks and were compared with corresponding controls. The mice were placed in the following groups, with 8 animals in each group: (1) intact control (C) with regular diet and no UV-B exposure, (2) intact control with UV-B exposure (CR), (3) calorie-restricted diet (CrC), (4) calorie-restricted diet with UV-B exposure (CrR), (5) obesity diet (OC), and (6) obesity diet with UV-B exposure (OR). The experiment was conducted during October through December 2013. Tissue processing and histological analysis were completed in 2016.

Main Outcomes and Measures

Histomorphometric analysis was performed on paraffin-embedded skin sections stained by histological and immunohistochemical methods for estimation of epidermal thickness, epidermal proliferating cell nuclear antigen index, collagen I, elastic fibers, fibroblasts, mast cells, dermal cellularity, and adipose layer ratio. Changes in wrinkles were noted.

Results

Hairless female mice (age range, 6-8 weeks) were obtained. With a normal diet, changes from UV-B irradiation occurred in epidermal thickness, epidermal proliferating cell nuclear antigen index, collagen I, elastic fibers, fibroblasts, and mast cells, which were modestly influenced by an obesity diet. Calorie restriction influenced the skin in nonirradiated control animals, with higher values for most variables. After UV-B exposure in animals with calorie restriction, epidermal thickness was increased, but other variables were unaffected. Animals receiving the calorie-restricted diet lost weight when exposed to long-term UV-B irradiation. Wrinkles were reduced in the calorie-restricted control group and in UV-B-exposed animals who received the obesity diet.

Conclusions and Relevance

Dietary alterations seem to modify histopathological responses to UV-B exposure in the skin of hairless mice.

Level of Evidence

NA.

Protective effects of astaxanthin on skin deterioration

Astaxanthin is a carotenoid with potent antioxidant and anti-inflammatory activity. To evaluate the anti-inflammatory effect of astaxanthin on skin deterioration, we confirmed its role in epidermal-dermal interactions in vitro. Astaxanthin treatment suppressed ultraviolet B (UVB)-induced inflammatory cytokine secretion in keratinocytes, and matrix metalloproteinase-1 secretion by fibroblasts cultured in UVB-irradiated keratinocyte medium. To verify these findings, we conducted a 16-week clinical study with 65 healthy female participants. Participants were orally administered either a 6 mg or 12 mg dose of astaxanthin or a placebo. Wrinkle parameters and skin moisture content significantly worsened in the placebo group after 16 weeks. However, significant changes did not occur in the astaxanthin groups. Interleukin-1α levels in the stratum corneum significantly increased in the placebo and low-dose groups but not in the high-dose group between weeks 0 and 16. This study was performed in Japan from August to December, when changing environmental factors, such as UV and dryness, exacerbate skin deterioration. In conclusion, our study suggests that long-term prophylactic astaxanthin supplementation may inhibit age-related skin deterioration and maintain skin conditions associated with environmentally induced damage via its anti-inflammatory effect. (UMIN Clinical Trials Registry ID: UMIN000018550)