Skin aging and natural photoprotection

Is Cutaneous T-Cell Lymphoma Caused by Ultraviolet Radiation? A Comparison of UV Mutational Signatures in Malignant Melanoma and Mycosis Fungoides

Ultraviolet (UV) radiation is a strong environmental carcinogen responsible for the pathogenesis of most skin cancers, including malignant melanoma (MM) and non-melanoma (keratinocyte) skin cancers. The carcinogenic role of UV was firmly established based on epidemiological evidence and molecular findings of the characteristic mutation signatures which occur during the excision repair of cyclobutane pyrimidine dimers and 6,4-photoproducts. The role of UV in the pathogenesis of mycosis fungoides (MF), the most common type of primary cutaneous T-cell lymphoma, remains controversial. Here, we performed whole-exome sequencing of 61 samples of MF cells microdissected from cutaneous lesions, and compared their mutational signatures to 340 MMs. The vast majority of MM mutations had a typical UV mutational signature (SBS 7, SBS 38, or DSB 1), underscoring the key role of ultraviolet as a mutagen. In contrast, the SBS 7 signature in MF comprised < 5% of all mutations. SBS 7 was higher in the intraepidermal MF cells (when compared to the dermal cells) and in the cells from tumors as compared to that in early-stage plaques. In conclusion, our data do not support the pathogenic role of UV in the pathogenesis of MF and suggest that the UV mutations are the result of the cumulative environmental ultraviolet exposure of cutaneous lesions rather than an early mutagenic event.

Novelty Cosmetic Filters Based on Nanomaterials Composed of Titanium Dioxide Nanoparticles

The following work describes the synthesis of new physical filters based on TiO₂/SiO₂ and TiO₂/Ag nanostructures. Titanium dioxide nanoparticles (TiO₂ NPs) were applied as control material and a popular physical UV filter. The advantage of using materials on the nanometer scale is the elimination of the skin whitening effect that occurs when using photoprotective cosmetics containing titanium dioxide on a macro scale. In addition, the silica coating makes the material less harmful, and the silver coating enriches the material with antibacterial properties. Nanoparticles and nanostructures have been characterized by Energy Dispersive X-Ray Analysis (EDX), the Scanning Electron Microscope (SEM), Transmission Electron Microscopy (TEM), and Fourier-Transform Infrared Spectroscopy (FT-IR) methods. Due to the use of physical filters in anti-radiation protection cosmetics, water-in-oil (W/O) emulsion has been prepared. All cosmetic formulations have been tested for stability. The sun protection research with the Sun Protection Diagnostic SP37 was carried out. These studies made it possible to determine the natural sun protection time and to compare the synthesized materials. Furthermore, one of the most important parameters when describing this type of cosmetic is water resistance, which has also been measured. The results show that the new type of material of TiO₂/Ag used as a new physical filter in emulsion W/O shows the best sun protection compared with other obtained nanomaterials. It is most likely due to the improved optical properties of the combination of noble metals, for example, silver with TiO₂.

Distinctive structure, composition and biomechanics of collagen fibrils in vaginal wall connective tissues associated with pelvic organ prolapse

Collagen is the predominant structural protein within connective tissues. Pelvic organ prolapse (POP) is characterized by weakening of the pelvic floor connective tissues and loss of support for pelvic organs. In this study, we examined the multiscale structure, molecular composition and biomechanics of native collagen fibrils in connective tissues of the posterior vaginal fornix collected from healthy women and POP patients, and established the correlation of these properties with clinical POP quantification (POP-Q) scores. The collagen characteristics, including collagen amount, ratio of Collagen I and Collagen III, collagen fibril d-period, alignment and stiffness, were found to change progressively with the increase of the clinical measurement of Point C, a measure of uterine descent and apical prolapse. The results imply that a severe prolapse is associated with stiffer collagen fibrils, reduced collagen d-period, increased fibril alignment and imbalanced collagen synthesis, degradation and deposition. Additionally, prolapse progression appears to be synchronized with deterioration of the collagen matrix, suggesting that a POP-Q score obtained via a non-invasive clinical test can be potentially used to quantitatively assess collagen abnormality of a patient's local tissue. STATEMENT OF SIGNIFICANCE: Abnormal collagen metabolism and deposition are known to associate with connective tissue disorders, such as pelvic organ prolapse. Quantitative correlation of the biochemical and biophysical characteristics of collagen in a prolapse patient's tissue with the clinical diagnostic measurements is unexplored and unestablished. This study fills the knowledge gap between clinical prolapse quantification and the individual's cellular and molecular disorders leading to connective tissue failure, thus, provides the basis for clinicians to employ personalized treatment that can best manage the patient's condition and to alert pre-symptomatic patients for early management to avoid unwanted surgery.

Biochemical, structural and physical changes in aging human skin, and their relationship

Skin is the largest organ of the human body, having the purpose of regulating temperature, protecting us from microbes or mechanical shocks, and allowing the sensations from touch. It is generally accepted that aging induces profound changes in the skin's biochemical, structural and physical properties, which can lead to impaired biological functions and/or diverse diseases. So far, the effects of aging on these skin properties have been well documented. However, very few studies have focused exclusively on the relationship among these critical properties in the aging process, which is this review's primary focus. Many in vivo, ex vivo, and in vitro techniques have been previously used to characterize these properties of the skin. This review aims to provide a comprehensive overview on the effects of aging on the changes in biochemical, structural, and physical properties, and explore the potential mechanisms of skin with the relation between these properties. First, we review different or contradictory results of aging-related changes in representative parameters of each property, including the interpretations of the findings. Next, we discuss the need for a standardized method to characterize aging-related changes in these properties, to improve the way of defining age-property relationship. Moreover, potential mechanisms based on the previous results are explored by linking the biochemical, structural, and physical properties. Finally, the need to study changes of various functional properties in the separate skin layers is addressed. This review can help understand the underlying mechanism of aging-related alterations, to improve the evaluation of the aging process and guide effective treatment strategies for aging-related diseases.

A new visible light absorbing organic filter offers superior protection against pigmentation by wavelengths at the UVR-visible boundary region

Skin pigmentation by solar ultraviolet radiation (UVR; ~295-400 nm) is well established. More recently, visible light (VL; 400-740 nm) has been shown to induce rapid pigmentation. Such pigmentation is thought to be caused by oxidative stress, which has associations with skin cancer and photoageing. However, the UVR-VL boundary region has been less well studied. The lower back of healthy Fitzpatrick skin type II-IV individuals was irradiated with increasing doses of narrow-band 385 nm and 405 nm radiation. Pigmentation change was measured immediately, 6 h and 24 h post-irradiation using two reflectance spectroscopy devices and visual grading. Pigmentation was dose-dependently increased in all skin types and time points for both spectra. Two sunscreens, both labelled SPF 15 and UVA protective in the EU and USA (but with different Boots star rating in the UK, 2* vs 5*) were compared. Their formulations were the same apart from the addition of a new organic filter bis-(diethylaminohydroxybenzoyl benzoyl) piperazine (BDBP) that absorbs between 350 and 425 nm. The product that lacked BDBP provided minimal protection against pigmentation, but its addition provided almost complete protection. This demonstrates the needs to improve photoprotection at the UVR-visible border and for sunscreens to act as neutral density filters.

Effect of green tea extract loaded chitosan microparticles on facial skin: A split-face, double-blind, randomized placebo-controlled study

INTRODUCTION

The bioactivities of green tea extract were indicated to promote skin health in vitro. Few clinical studies reported on skin nourishment of topical applying green tea extract due to the limited skin absorption.

METHODS

This current study evaluated the clinical effectiveness and safety of green tea extract encapsulated chitosan microparticles (GTP) in emulsion base on a split-face, double-blind, randomized placebo-controlled study. Twenty-nine female volunteers were recruited into the study. They were randomly assigned to apply GTP and placebo creams on each half face for 8 weeks. The facial skin properties on both sides were monitored and evaluated every 2 weeks.

RESULTS

The results revealed that skin elasticity (R2) of half face treated with GTP cream (0.748 ± 0.05) was superior to another that received placebo cream (0.722 ± 0.05) at 4th week. In addition, melanin index implying skin dullness of the half face that received GTP cream significantly improved within the 6th week after application (placebo =295.60 ± 58.81, GTP =282.70 ± 59.62). Most importantly, the photographs clearly indicated that the decreasing in facial wrinkles of volunteers applied with GTP cream was more than those applying placebo cream. Signs of skin irritation were not evident in both treatment and placebo cream groups.

CONCLUSION

Based on study outcomes, the green tea extract encapsulated chitosan microparticles appear to be the promising active candidate for promoting skin elasticity and improving skin dullness and wrinkles.

Photoprotective Effect of Artemisia sieversiana Ehrhart Essential Oil Against UVB-induced Photoaging in Mice

Photoaging refers to the extrinsic aging resulting from ultraviolet (UV) irradiation, which impacts skin appearance and is accompanied by the risk of skin carcinoma. Developing natural products as photoprotective agents is of great interest in cosmetic industry nowadays. The present study aimed at investigating the possible use of Artemisia sieversiana Ehrhart essential oil (AEO) for the prevention of photoaging induced by UVB. AEO was characterized by chamazulene, which accounted for 38.92% among total 51 identified compounds. In in vitro assays, AEO was found to be a moderate antioxidant and good UVB filter with photostability. A UVB-induced photoaging mice model was established with three AEO formulations (0.1%, 0.5% and 1.5%, w/w) topically applied prior to UVB irradiation. The activities of catalase, particularly superoxide dismutase of skin increased, while malondialdehyde content decreased in AEO groups as compared with model controls. The production of matrix metalloproteinases (MMP-1 and MMP-3) and depletion of hydroxyproline in skin were inhibited by AEO in a dose-dependent manner. Histological evaluation indicated that AEO decreased epidermal thickness, inflammatory cell infiltration, collagen degradation and elastin aberrance. These findings indicated that AEO could be a promising sunscreen agent in protecting the skin against photoaging.

Raman confocal microscopy and biophysics multiparametric characterization of the skin barrier evolution with age

Skin aging is a multifactorial phenomenon that involves alterations at the molecular, cellular and tissue levels. Our aim was to carry out a multiparametric biophysical and Raman characterization of skin barrier between individuals of different age groups (<24 and >70 years old). Our results showed a significant decrease of lipids to proteins ratio overall the thickness of the stratum corneum and higher lateral packing in the outer part of the SC for elderly. This can explain the decrease in trans epidermal water loss measured values rather than only SC thickening. Both age groups showed similar water content at SC surface while elderly presented higher water content in deep SC and viable epidermis. Mechanical measurements showed a decrease in the elasticity and an increase in the fatigability with age and were correlated with partially bound water. Highest correlation and anti-correlation values were observed for the deepest part of the SC and the viable epidermis.

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.

Tissue Mechanics in Haired Murine Skin: Potential Implications for Skin Aging

During aging, the skin undergoes changes in architecture and composition. Skin aging phenotypes occur due to accumulated changes in the genome/epigenome, cytokine/cell adhesion, cell distribution/extracellular matrix (ECM), etc. Here we review data suggesting that tissue mechanics also plays a role in skin aging. While mouse and human skin share some similarities, their skin architectures differ in some respects. However, we use recent research in haired murine skin because of the available experimental data. Skin suffers from changes in both its appendages and inter-appendage regions. The elderly exhibit wrinkles and loose dermis and are more likely to suffer from wounds and superficial abrasions with poor healing. They also have a reduction in the number of skin appendages. While telogen is prolonged in aging murine skin, hair follicle stem cells can be rejuvenated to enter anagen if transplanted to a young skin environment. We highlight recent single-cell analyses performed on epidermis and aging human skin which identified new basal cell subpopulations that shift in response to wounding. This may be due to alterations of basement membrane stiffness which would change tissue mechanics in aging skin, leading to altered homeostatic dynamics. We propose that the extracellular matrix (ECM) may play a key role as a chemo-mechanical integrator of the multi-layered senescence-associated signaling pathways, dictating the tissue mechanical landscape of niche microenvironments in aging phenotypes. We show examples where failed chemo-mechanical signaling leads to deteriorating homeostasis during skin aging and suggest potential therapeutic strategies to guide future research to delay the aging processes.

Traditional fermented foods with anti-aging effect: A concentric review

Fermentation has been applied since antiquity as a way to preserve foodstuff or as a necessary step in the production of a variety of products. The research was initially focused on accurate description of production procedure and identification of parameters that may affect the composition and dynamics of the developing micro-communities, since the major aim was standardization and commercial exploitation of the products. Soon it was realized that consumption of these products was associated with an array of health benefits, such as anti-hypertensive, anti-inflammatory, anti-diabetic, anti-carcinogenic and anti-allergenic activities. These were credited to the microorganisms present in the fermented products as well as their metabolic activities and the bio-transformations that took place during the fermentation process. Aging has been defined as a gradual decline in the physiological function and concomitantly homeostasis, which is experienced by all living beings over time, leading inevitably to age-associated injuries, diseases, and finally death. Research has focused on effective strategies to delay this process and thus increase both lifespan and well-being. Fermented food products seem to be a promising alternative due to the immunomodulatory effect of microorganisms and elevated amounts of bioactive compounds. Indeed, a series of anti-aging related benefits have been reported, some of which have been attributed to specific compounds such as genistein and daidzein in soybeans, while others are yet to be discovered. The present article aims to collect and critically discuss all available literature regarding the anti-aging properties of fermented food products.

Andrographis Paniculata and Its Bioactive Diterpenoids Protect Dermal Fibroblasts Against Inflammation and Oxidative Stress

Andrographis paniculata (Burm.f.) has long been used in ayurvedic medicine through its anti-inflammatory properties. However, its protective effect of skin aging has not been studied in vitro. This study aimed to investigate the anti-aging effects of methanolic extract (ME), andrographolide (ANDRO), neoandrographolide (NEO), 14-deoxyandrographolide (14DAP) and 14-deoxy-11,12-didehydroandrographolide (14DAP11-12) on human dermal fibroblasts (HDFa) under pro-oxidant or pro-inflammatory condition. The in vitro anti-aging capacity of ME, ANDRO, NEO, 14DAP, and 14DAP11-12 (1, 2.5 and 5 µg/mL) was performed in HDFa. Oxidative stress and inflammation were induced by hydrogen peroxide and lipopolysaccharide/TNF-α, respectively. Reactive oxygen species (ROS) production was measured by the fluorescence of DCF-DA probe and cytokines were quantified by ELISA (IL6 and IL8) or RTqPCR (TNF-α). Procollagen type I production was determined by an ELISA. Our results showed a decrease in ROS production with ME and 14DAP at 5 µg/mL and 1 µg/mL, respectively. Furthermore, IL-6 production and TNF-α expression decreased under ANDRO and ME at 5 µg/mL. Our data indicated that ME and 14DAP protect from oxidative stress. Additionally, ME and ANDRO decreased an inflammation marker, IL-6. This suggests their potential natural treatment against skin damage. Hence, their applications could be of interest in cosmetics for preventing skin ageing.

D-tyrosine adds an anti-melanogenic effect to cosmetic peptides

D-tyrosine is known to negatively regulate melanin synthesis by inhibiting tyrosinase activity. Here, we further reveal that peptides containing terminal D-tyrosine can reduce the melanin contents of human melanocytes. The addition of D-tyrosine to the terminus of the commercial anti-wrinkle peptide, pentapeptide-18 endowed the peptide with the ability to reduce the melanin content and tyrosinase activity in human MNT-1 melanoma cells and primary melanocytes. Consistently, terminal D-tyrosine-containing pentapeptide-18 inhibited the melanogenesis induced by α-MSH treatment or UV irradiation of MNT-1 cells and reduced melanin synthesis in the epidermal basal layer of a 3D human skin model. Furthermore, the addition of D-tyrosine to an anti-aging peptide (GEKG) or an anti-inflammatory peptide (GHK) endowed these short peptides with anti-melanogenic effects without altering their intrinsic effects. Together, these data suggest that the addition of D-tyrosine at the terminus of a short cosmetic peptide adds an anti-melanogenic effect to its intrinsic cosmetic effect. Our work offers a novel means of generating dual-function cosmetic peptides.

The importance of the neuro-immuno-cutaneous system on human skin equivalent design

The skin is a highly complex organ, responsible for sensation, protection against the environment (pollutants, foreign proteins, infection) and thereby linked to the immune and sensory systems in the neuro-immuno-cutaneous (NIC) system. Cutaneous innervation is a key part of the peripheral nervous system; therefore, the skin should be considered a sensory organ and an important part of the central nervous system, an 'active interface' and the first connection of the body to the outside world. Peripheral nerves are a complex class of neurons within these systems, subsets of functions are conducted, including mechanoreception, nociception and thermoception. Epidermal and dermal cells produce signalling factors (such as cytokines or growth factors), neurites influence skin cells (such as via neuropeptides), and peripheral nerves have a role in both early and late stages of the inflammatory response. One way this is achieved, specifically in the cutaneous system, is through neuropeptide release and signalling, especially via substance P (SP), neuropeptide Y (NPY) and nerve growth factor (NGF). Cutaneous, neuronal and immune cells play a central role in many conditions, including psoriasis, atopic dermatitis, vitiligo, UV-induced immunosuppression, herpes and lymphomas. Therefore, it is critical to understand the connections and interplay between the peripheral nervous system and the skin and immune systems, the NIC system. Relevant in vitro tissue models based on human skin equivalents can be used to gain insight and to address impact across research and clinical needs.

Asiatic Acid Glucosamine Salt Alleviates Ultraviolet B-induced Photoaging of Human Dermal Fibroblasts and Nude Mouse Skin

Herbal extracts including asiatic acid (AA) have become popular candidates of anti-photoaging agents due to their anti-inflammatory and antioxidant properties and minimal side effect. Nevertheless, low bioavailability due to poor solubility limits their practical application. In this study, a highly bioavailable form of AA called AAGS (compounded by asiatic acid and glucosamine) was investigated for its anti-photoaging effect using both in vitro and in vivo models along with UVB irradiation. The results showed that AAGS alleviated UVB-induced cell proliferation inhibition by reducing G2 phase arrest and cell apoptosis rate as well as the gene expressions of P53, BAX, CASPASE 3 and CASPASE 9, but enhancing BCL-2 expression. It also reduced the production of reactive oxygen species along with increased gene expression of GPX-1 and downregulated the gene expression of IL-1β, IL-6, IL-8, IL-17 and TNF-α compared to nontreated cells. In vivo results demonstrated the antiphotodamaging effects by restoring skin thickness, collagen content and reducing MMPs expression, which are also supported by reduced MMPs gene expression and enhanced collagen I and TGF-β1 gene expression in vitro. Thus, AAGS may become a potential anti-photoaging agent for topical use due to its capability of self-assembling into a water gel.

Phenotype plasticity as enabler of melanoma progression and therapy resistance

Malignant melanoma is notorious for its inter- and intratumour heterogeneity, based on transcriptionally distinct melanoma cell phenotypes. It is thought that these distinct phenotypes are plastic in nature and that their transcriptional reprogramming enables heterogeneous tumours both to undergo different stages of melanoma progression and to adjust to drug exposure during treatment. Recent advances in genomic technologies and the rapidly expanding availability of large gene expression datasets have allowed for a refined definition of the gene signatures that characterize these phenotypes and have revealed that phenotype plasticity plays a major role in the resistance to both targeted therapy and immunotherapy. In this Review we discuss the definition of melanoma phenotypes through particular transcriptional states and reveal the prognostic relevance of the related gene expression signatures. We review how the establishment of phenotypes is controlled and which roles phenotype plasticity plays in melanoma development and therapy. Because phenotype plasticity in melanoma bears a great resemblance to epithelial-mesenchymal transition, the lessons learned from melanoma will also benefit our understanding of other cancer types.

Anti-pollution cosmetic-based one-step formation of w/o/w multiple emulsion containing D-biotin for skin protection: fabrication and in vitro and in vivo evaluation

Continuous contact of air pollutants on human skin has produced early ageing and led to roughness, dryness, poor elasticity, increased wrinkling and irregular pigmentation of the skin. The present study was carried out to fabricate an anti-pollution cosmetic-based w/o/w multiple emulsion containing D-biotin, prepared by a one-step formation as protection for the skin against the effects of air pollutants and further used for in vitro and in vivo evaluation. A similar multiple emulsion without D-biotin was also prepared in the same way. Each of the tested multiple emulsions (CB2 and CF2) was applied to the cheeks of 15 human volunteers for a testing period of 90 days. Both emulsions were assessed for skin melanin, erythema, hydration and elasticity values. The droplet sizes of CB2 and CF2 stored in the dark were 10.92 ± 0.23 and 15.4 ± 0.12 μm, respectively. The size distributions of CB2 and CF2 ranged from 4.55 ± 0.1 to 26.056 ± 0.34 μm and from 1.97.16 ± 1.2 to 45.13 ± 2.17 μm, respectively. The rheological parameters showed non-Newtonian, pseudo-plastic and shear thinning behaviour, while pH remained within an acceptable range. No considerable physical changes were observed. The skin irritation testing indicated that CB2 and CF2 were safe after application and did not cause any skin irritation. The skin melanin, erythema, moisture and elasticity values of both the right and left cheeks of the volunteers were measured at baseline visits: 15, 30, 45, 60, 75 and 90 days of time intervals. While CB2 showed insignificant effects, therefore, it was demonstrated that CF2 decreased skin erythema content and increased skin elasticity and hydration significantly but had an insignificant effect on skin melanin content with respect to time. Good sensory attributes were also achieved. Therefore, CF2 is a promising new approach for protection of the skin from the deleterious effects of air pollutants.

Protective Effects of Kuding Tea (Ilex kudingcha C. J. Tseng) Polyphenols on UVB-Induced Skin Aging in SKH1 Hairless Mice

In this study, the protective effects of Kuding tea polyphenols (KTPs) on ultraviolet B (UVB)-induced skin injury of SKH1 hairless mice were studied. The ion precipitation method was used for extraction of polyphenols from Kuding tea. High-performance liquid chromatography showed that KTPs contains chlorogenic acid, cryptochlorogenic acid, isochlorogenic acid B, isochlorogenic acid A, and isochlorogenic acid C. SKH1 hairless mice were induced skin aging using 2.0 mW/s intensity of 90 mJ/cm² UV light once a day for seven weeks. The 2.5% and 5% KTPs solution was smeared on 2 cm² of back skin of skin aging mice twice a day. Mouse experiments showed that KTP strongly increased the serum levels of total superoxide dismutase (T-SOD) and catalase (CAT) and reduced those of malondialdehyde, interleukin 6 (IL-6), IL-1β, and tumor necrosis factor alpha (TNF-α) in mice with UVB-induced skin damage. KTP also increased the levels of type 1 collagen (Col I), hydroxyproline, and hyaluronic acid and reduced those of Col III and hydrogen peroxide in the damaged skin tissues of mice. Pathological observations of tissues stained with H & E, Masson’s trichrome, Verhoeff, and toluidine blue showed that KTPs could protect skin cells, collagen, and elastin and decrease the number of mast cells, thus inhibiting skin damage. Quantitative PCR and western blot assays showed that KTP upregulated the mRNA and protein expression of tissue inhibitor of metalloproteinase 1 (TIMP-1), TIMP-2, copper/zinc-SOD, manganese-SOD, CAT, and glutathione peroxidase and downregulated the expression of matrix metalloproteinase 2 (MMP-2) and MMP-9. In addition, the same concentration of KTP had stronger protective effects than vitamin C. The results of this study demonstrate that KTPs have good skin protective effects, as they are able to inhibit UVB-induced skin damage.

An Innovative Thread-looping Method for Facial Rejuvenation: Minimal Access Multiple Plane Suspension

Supplemental Digital Content is available in the text.

Background:

Management of facial rejuvenation has evolved over past decades. Facelift with barbed suture is a minimally invasive surgical technique for facial rejuvenation. This study examined the efficacy and associated complications of a new thread-looping procedure called minimal access multiple plane suspension.

Methods:

A total of 103 thread lifts were performed between 2014 and 2017. Patient satisfaction and adverse effects were evaluated.

Results:

In the majority of patients (88/103, 85.4%), the results obtained were considered satisfactory 3 months after the procedure. The incidence of complications was low. Only 5.8% of the patients had slight postoperation asymmetry that was easily corrected. Minor complications experienced by patients included palpable suture knots (12.6%), persistent facial swelling (7.88%), and facial dimpling (2.9%). The causes of procedure-related complications were reviewed and discussed.

Conclusion:

Reinforced by select anchoring points, "minimal access multiple plane suspension" suspends ptotic anatomic tissues, serving as an effective facial rejuvenation procedure with minimal downtime and satisfactory cosmetic results.

Acquired disorders with hypopigmentation: A clinical approach to diagnosis and treatment

Acquired hypopigmented skin changes are commonly encountered by dermatologists. Although hypopigmentation is often asymptomatic and benign, occasional serious and disabling conditions present with cutaneous hypopigmentation. A thorough history and physical examination, centered on disease distribution and morphologic findings, can aid in delineating the causes of acquired hypopigmented disorders. The second article in this 2-part continuing medical education series focuses on conditions with a hypopigmented phenotype. Early diagnosis and appropriate management of these disorders can improve a patient's quality of life, halt disease progression, and prevent irreversible disability.

Protection against UVB-Induced Wrinkle Formation in SKH-1 Hairless Mice: Efficacy of Tricin Isolated from Enzyme-Treated Zizania latifolia Extract

Tricin, a flavone found mainly in rice bran and sugarcane, has various beneficial effects. It has proven to be a clinically safe and selective potent inhibitor of different cancer cell lines. In this study, we evaluated the efficacy of enzyme-treated Zizania latifolia (ETZL) and its major active compound tricin on skin photoaging in SKH-1 hairless mice. Tricin (0.3 mg/kg) and ETZL (50, 150, and 300 mg/kg) were orally administrated to mice for 14 weeks; no cytotoxicity was observed during the entire experimental period. After UVB exposure, we observed significant increases in keratinization, coarse wrinkles, loss of moisture, thickened epidermis, and collagen fiber degradation in the dorsal skin. These features of photoaging were significantly suppressed after oral administration of tricin or ETZL. In addition, the protein expression of collagen effectively increased in ETZL (150 and 300 mg/kg)-treated mice, while the increased metalloproteinase (MMP)-1 and MMP-3 expressions were reduced after exposure to tricin or ETZL, although the effects were not dose-dependent. These data indicate that ETZL may be effective for attenuation of UVB-induced skin damage and photoaging in hairless mice, possibly by inhibiting MMPs expression.

Dislocation rate increases with bariatric surgery before total hip arthroplasty

INTRODUCTION

Annually in the USA, 113,000 patients with refractory obesity undergo bariatric surgery (BS), and a subset does so in order to lower body mass index to become a more desirable total hip arthroplasty (THA) candidate. This study aims to evaluate THA risk with and without bariatric surgery.

METHODS

12,160 patients were identified in a claim-based review of the entire Medicare database with ICD-9 codes to identify patients in three groups. Patients who underwent BS prior to THA (Group I: 1,545 experimental group) and two control groups that did not undergo BS but had either a body mass index >40 (Group II: 6,918 bariatric control) or <25 (Group III: 3,697 normal weight control). Preoperative demographics/comorbidities and short-term medical (30 day) and long-term surgical (90-day and 2-year) complications were evaluated.

RESULTS

Group I had female predominance, youngest age, and highest incidence of: deficiency anaemia, cardiovascular disease, liver disease, diabetes, polysubstance abuse, psychiatric disorders and smoking. At 2 years, Group I had approximately twice the dislocation and revision risk compared to both Groups II and III; Groups I and II had over four times the risk of infection and wound complications compared to Group III.

CONCLUSION

In the Medicare population, these patients continue to have complication rates similar to and sometimes greater than obese patients with no prior bariatric surgery. Greater dislocation risk is possibly due to ligamentous laxity related to decreased collagen/elastin and/or component malposition due to intraoperative visualisation challenges.

Towards elucidating the photochemistry of the sunscreen filter ethyl ferulate using time-resolved gas-phase spectroscopy

Ultrafast time-resolved ion yield (TR-IY) and velocity map imaging spectroscopies are employed to reveal the relaxation dynamics after photoexcitation in ethyl 4-hydroxy-3-methoxycinnamate (ethyl ferulate, EF), an active ingredient in commercially available sunscreens. In keeping with a bottom-up strategy, the building blocks of EF, 2-methoxy-4-vinylphenol (MVP) and 4-hydroxy-3-methoxycinnamyl alcohol (coniferyl alcohol, ConA), were also studied to assist in our understanding of the dynamics of EF as we build up in molecular complexity. In contrast to the excited state dynamics of MVP and ConA, which are described by a single time constant (>900 ps), the dynamics of EF are described by three time constants (15 ± 4 ps, 148 ± 47 ps, and >900 ps). A mechanism is proposed involving internal conversion (IC) between the initially excited S₁(1¹ππ*) and S₂(1¹nπ*) states followed by intramolecular vibrational redistribution (IVR) on both states, in competition with intersystem crossing onto neighbouring triplet states (15 ± 4 ps). IVR and IC within the triplet manifold then ensues (148 ± 47 ps) to populate a low-lying triplet state (>900 ps). Importantly, the fluorescence spectrum of EF at the S₁ origin, along with the associated lifetime (6.9 ± 0.1 ns), suggests that population is trapped, during initial IVR, on the S₁(1¹ππ*) state. This serves to demonstrate the complex, competing dynamics in this sunscreen filter molecule.

Long-term administration of pDC stimulative lactic acid bacteria, Lactococcus lactis strain Plasma, prevents immune-senescence and decelerates individual senescence

Aging is accompanied by the decline in immune function, resulting in increasing susceptibility to infectious diseases and tumorigenesis. In our previous reports, we showed that Lactococcus lactis subsp. lactis strain Plasma (LC-Plasma) stimulated plasmacytoid dendritic cells (pDCs), which play an important role in viral infection, and oral administration of LC-Plasma showed prophylactic effects against viral infection both in mice and humans. However, the effects of long-term administration of LC-Plasma are not known. In this study, we investigated the effect of long-term oral administration of LC-Plasma on IFN-α induction activity and individual senescence in the senescence-accelerated mice strains Prone 1 (SAMP1) and Prone 10 (SAMP10). LC-Plasma administration promoted IFN-α induction activity and increased the naïve T cell ratio in SAMP1 mice. In SAMP10 mice, in addition to preventing a decrease in the naïve T cell ratio, aging-associated skin thinning was suppressed histologically and the expression of representative tight junction genes, such as Claudin-1 and Zo-1, was increased. Furthermore, age-related muscle weight loss tended to be suppressed in the LC-Plasma group and expression of the muscle degeneration gene FoxO-1 was significantly suppressed. Related to these phenotypes, the senescence score in the LC-Plasma group was significantly decreased at 47 weeks of age compared with that in the control group. Taken together, long-term oral administration of LC-Plasma could prevent immune-senescence and other senescence phenotypes at the organ level. Therefore, LC-Plasma is suggested to be a useful functional food material for decelerating individual senescence.

A Glimpse into Uveitis in the Aging Eye: Pathophysiology, Clinical Presentation and Treatment Considerations

Uveitis describes a group of inflammatory conditions of the eye that have various underlying causes and clinical presentations. Susceptibilities to uveitis in the elderly may be attributed to age-related risk factors such as immunosenescence, increased immunological inflammatory mediators, and autoimmunity. Overall, anterior uveitis is more common than posterior and panuveitis in the general population and also in the elderly. Some causes of uveitis in the elderly are herpes simplex virus, ocular ischemic syndrome, sarcoidosis, and central nervous system lymphoma, and these will be discussed in detail herein. Eye care professionals need to consider the wide differential for uveitis, obtain the appropriate history, conduct a detailed clinical examination, and tailor management to the clinical presentation and underlying cause of disease. The challenges of polypharmacy and nonadherence in the elderly impact patient outcomes and must be taken into consideration when considering treatment.

Long-term administration of pDC-Stimulative Lactococcus lactis strain decelerates senescence and prolongs the lifespan of mice

The decline in immune function caused by aging increases the risk of infectious diseases, tumorigeneses and chronic inflammation, resulting in accelerating senescence. We previously reported a lactic acid bacteria, Lactococcus lactis strain Plasma (synonym of Lactococcus lactis subsp. lactis JCM 5805, Lc-Plasma), that stimulates plasmacytoid dendritic cells (pDCs), which play a crucial role in phylaxis from viral infection. In this study, we investigated the anti-aging effects of long-term oral administration of Lc-Plasma in a senescence-accelerated mouse strain, SAMP6. Mice given Lc-Plasma showed a significant improvement in survival rate at 82 weeks and a decreased senescence score as compared with control mice throughout this study. Anatomic analysis at 82 weeks revealed that the frequency of altered hepatocellular foci was significantly lower, and the incidence of other pathological findings in the liver and lungs tended to be lower in Lc-Plasma mice than in control mice. Transcription level of the IL-1β gene in lungs also tended to be lower in Lc-Plasma mice. Furthermore, the thinning of skin and age-related decrease in muscle mass were also significantly suppressed in the Lc-Plasma group as compared with the control group. Consistent with these phenotypic features, pDCs activity was significantly higher in Lc-Plasma mice than in control mice. In conclusion, long-term administration of Lc-Plasma can decelerate senescence and prolong lifespan via maintenance of the immune system due to activation of pDCs.

Anti-aging Properties of Conditioned Media of Epidermal Progenitor Cells Derived from Mesenchymal Stem Cells

INTRODUCTION

Reduced number and activities of epidermal stem cells are related to the features of photoaged skin. It was reported that conditioned media from various stem cell cultures are capable of improving the signs of cutaneous aging. This work was performed to establish epidermal progenitor cells derived from mesenchymal stem cells, and to evaluate the anti-aging efficacy of its conditioned media.

METHODS

Epidermal progenitor cell culture was established by differentiation from mesenchymal stem cells, and its conditioned medium (EPC-CM) was prepared. Normal human dermal fibroblasts were exposed to hydrogen peroxide and the protective effects of EPC-CM were investigated, monitoring intracellular reactive oxygen species (ROS), cellular defense enzymes, collagen biosynthesis, and mitogen-associated protein kinase (MAPK) signaling. Anti-aging efficacy of cosmetic essence (5% EPC-CM) was evaluated by a clinical test with 25 Korean women aged between 29 and 69.

RESULTS

Hydrogen peroxide hindered proliferation of fibroblasts and increased the levels of intracellular ROS. Pretreatment of EPC-CM protected fibroblasts from oxidative stress as shown by accelerated proliferation and reduced ROS generation. EPC-CM effectively prevented hydrogen peroxide-induced alterations of the activities, as well as mRNA and protein levels, of antioxidative enzymes, such as superoxide dismutase, catalase, and glutathione peroxidase. Reduced type I collagen biosynthesis and stimulated phosphorylation of MAPK signaling proteins, induced by oxidative damage, were also prevented by EPC-CM. In clinical study, wrinkle, depression, and skin texture were improved by the topical application of a formulation containing 5% EPC-CM within 4 weeks.

CONCLUSION

Epidermal progenitor cell culture was established, and its conditioned medium was developed for anti-aging therapy. EPC-CM improved signs of skin aging in clinical study, possibly via activation of cellular the defense system, as supported by in vitro results.

Protective effects of fermented honeybush (Cyclopia intermedia) extract (HU-018) against skin aging: a randomized, double-blinded, placebo-controlled study

BACKGROUND

Oxidative stress and photodamage resulting from ultraviolet radiation exposure play key roles in skin aging. Fermented Cyclopia intermedia, which is used to brew honeybush tea, exerts antioxidant and anti-wrinkle effects by inhibiting reactive oxygen species production and downregulating matrix metalloproteinase activity.

OBJECTIVES

This randomized, double-blinded, placebo-controlled study aimed to evaluate the efficacy and safety of fermented honeybush (Cyclopia intermedia) extract (HU-018) for skin rejuvenation.

METHODS

120 Korean subjects with crow's feet wrinkles were randomized to receive either low-dose extract (400 mg/day), high-dose extract (800 mg/day), or placebo (negative control, only dextran) for 12 weeks. Wrinkles were evaluated using JANUS^® and PRIMO pico^®. Skin elasticity, hydration and transepidermal water loss were measured.

RESULTS

Global skin wrinkle grade was significantly improved in both low-dose and high-dose groups compared to placebo group, as well as for skin hydration and elasticity. Both the low- and high-dose groups showed significantly decreased TEWL compared to the placebo group. There were no adverse effects during the entire study period.

CONCLUSION

Our data indicate that HU-018 is effective for improving skin wrinkles, elasticity, and hydration. Therefore, daily supplementation with fermented honeybush could be helpful for protecting against skin aging.

Cosmeceutical effect of ethyl acetate fraction of Kombucha tea by intradermal administration in the skin of aged mice

BACKGROUND/PURPOSE

Natural ingredients have been always an interesting approach to prolong youthful appearance of skin. One of the natural compounds is Kombucha tea (KT), which has been mainly used as an energy drink in Asian countries for a long time. Previous reports indicated that it has pharmaceutical and favorable wound repairing effects. The beneficial properties of KT are thought to be mainly due to the presence of fermentation products such as flavonoids and other polyphenols with inhibition of hydrolytic and oxidative enzymes and anti-inflammatory effects. These properties prompted us to study the anti-aging potential of KT and investigate its effective fraction in aged mice, METHODS: Kombucha tea was fractionated into chloroform, butanol, and ethyl acetate, and flavonoid content was determined. Young and old mice were used as control. KT ethyl acetate fraction (KEAf), which had the highest flavonoid content, was intradermally administered to old mice.

RESULTS

Administration of KEAf significantly increased the collagen content, NAD⁺ /NADH level, and concomitantly improved skin connective tissue abnormalities in the aged skin. No sensitivity or irritation was observed.

CONCLUSION

This finding suggested that KEAf can be a suitable candidate as a cosmetic product to improve aging-related skin abnormalities and regeneration of aged skin.

Blistering diseases in the mature patient

Autoimmune blistering diseases (AIBD) are a group of chronic diseases affecting the skin and mucous membranes, with different presentation, clinical course, histologic and immunopathologic findings, and different therapeutic approach. Blisters develop as a result of autoantibodies directed against distinct adhesion structures within desmosomes or within the basement membrane zone. The most common AIBD that develops in the elderly is bullous pemphigoid (previously also named "pemphigoid senilis"), but mature patients can also present with other AIBD as mucous membrane pemphigoid, epidermolysis bullosa acquisita, paraneoplastic pemphigus, pemphigus vulgaris, pemphigus foliaceus, linear IgA dermatosis, and dermatitis herpetiformis. There are no differences in treatment approach to mature patients with AIBD, but due to more common comorbidities, systemic therapy should be given with more caution and control, and due to distorted skin integrity in the aged skin, the safety concerns are increased with the long-term use of any topical medication.

Histological study on the effect of nicotine on adult male guinea pig thin skin

Tobacco smoking has been identified as an important factor in premature skin aging to detect the histological changes occurred in adult male guinea pig thin skin under the influence of low and high doses of nicotine; which constitutes approximately 0.6%–3.0% of the dry weight of tobacco. Fifteen adult male pigmented guinea pigs were equally divided into three groups: group I, control; group IIA, low dose nicotine treated; 3 mg/kg subcutaneously for 4 weeks; and group IIB, high dose nicotine treated; 6 mg/kg subcutaneously for 4 weeks. Specimens from the back thin skin were processed for light and electron microscopy. Nicotine administration revealed flattened dermo-epidermal junction and reduced rete ridges formation. Collagen bundles were disorganized with increased spaces between them. A reduction in the amount of elastic fibers in the dermis were also observed compared to group I. Ultrastructurally, keratinocytes had hyperchromatic nuclei, intracytoplasmic vacuoles, disruption of desmosomal junctions, irregular tonofilaments distribution, and increased inter-cellular spaces. These changes were more pronounced with high dose nicotine administration. The epidermal thickness was reduced in low dose nicotine administration. But, high dose nicotine administration revealed increased epidermal thickness compared to the control group. Nicotine induced structural changes of adult male guinea pig thin skin. These changes were more pronounced with high dose nicotine administration.

Photobiomodulation therapy action in wound repair skin induced in aged rats old: time course of biomarkers inflammatory and repair

Previous studies have discussed an inverse correlation between age and wound healing, because it relates to the association of aging with a gradual decrease in healing capacity. Treatment with photobiomodulation therapy (PBMT) improves wound healing by inducing increases in mitotic activity, numbers of fibroblasts, collagen synthesis, and neovascularization. Therefore, this study aimed to evaluate the effects of PBMT in cutaneous wound healing in aged rats. A punch biopsy of 8 mm in diameter was performed to produce a skin wound. The study included 45 male rats, of which 15 were young (30 days) and 30 were elderly (500 days). The 45 animals were distributed into 3 experimental groups, which were subjected to skin wounds and 1 aged group received PBMT, with a 30-mW laser beam (power density of 1.07 W/cm²), beam area of 0.028 cm², and λ660 nm produced through active phosphide Gallium-Aluminum-Indio (InGaAIP). The PBMT application took the form of a single-point transcutaneous method, with a total energy of 2 joules per wound site, energy density of 72 J/cm², and time of 1 min and 7 s. Analysis was performed to verify the effect of PBMT on the quantity of collagen I and III, metalloproteinase 3 and 9 (MMP-3 and MMP-9), tissue inhibitor of metalloproteinase-2 (TIMP-2) and of vascular endothelial growth factor (VEGF) at the wound site by immunohistochemistry, cytokine-induced neutrophil chemoattractant (CINC)-1, by enzyme-linked immunosorbent assay (ELISA) and interleukin (IL)-6 real-time polymerase chain reaction (RT-PCR). That we conclude LLLT is effective in the modulation of inflammatory mediators IL-6, CINC-1, VEGF, MMP-3, MMP-9 and TIMP-2 as well as increased collagen production in aged animals during different phases of the tissue regeneration process. However, the effects of PBMT obtained in the aged animals (aged LLLT group) suggest that new dosimetries should be tested to achieve better results.

An overview about oxidation in clinical practice of skin aging

Free radicals are unstable chemical species, highly reactive, being formed by cellular entities of different tissues. Increased production of these species without proper effective action of endogenous and exogenous antioxidant systems, generates a condition of oxidative stress, potentially provider of skin disorders that extend from functional impairments (skin cancer, dermatitis, chronic and acute inflammatory processes) even aesthetic character, with the destruction of structural proteins and cellular changes with the appearance of stains, marks and lines of expressions and other signs inherent to the intrinsic and extrinsic skin aging process. The antioxidants are chemical substances commonly used in clinical practice for topical application and may contribute in the fight against the radical species responsible for many skin damage. This paper summarized the main evidence of the benefits brought by the topical application of antioxidants in the skin, considering the amplitude of the indicative performance of antioxidant activity by in vitro and ex-vivo tests as well as in vivo tests. It is recognized that a breadth of product performance tests should be explored to truly identify the effectiveness of antioxidant products for an anti-aging effect.

Molecular mechanisms of green tea polyphenols with protective effects against skin photoaging

Whereas green tea has historically been consumed in high quantities in Northeast Asia, its popularity is also increasing in many Western countries. Green tea is an abundant source of plant polyphenols exhibiting numerous effects that are potentially beneficial for human health. Accumulating evidence suggests that green tea polyphenols confer protective effects on the skin against ultraviolet (UV) irradiation-induced acceleration of skin aging, involving antimelanogenic, antiwrinkle, antioxidant, and anti-inflammatory effects as well as prevention of immunosuppression. Melanin pigmentation in the skin is a major defense mechanism against UV irradiation, but pigmentation abnormalities such as melasma, freckles, senile lentigines, and other forms of melanin hyperpigmentation can also cause serious health and aesthetic issues. Furthermore, UV irradiation initiates the degradation of fibrillar collagen and elastic fibers, promoting the process of skin aging through deep wrinkle formation and loss of tissue elasticity. UV irradiation-induced formation of free radicals also contributes to accelerated photoaging. Additionally, immunosuppression caused by UV irradiation plays an important role in photoaging and skin carcinogenesis. In this review, we summarize the current literature regarding the antimelanogenic, antiwrinkle, antioxidant, and immunosuppression preventive mechanisms of green tea polyphenols that have been demonstrated to protect against UV irradiation-stimulated skin photoaging, and gauge the quality of evidence supporting the need for clinical studies using green tea polyphenols as anti-photoaging agents in novel cosmeceuticals.

Histological investigation of common insensate flaps obtained from the hand and forearm regions for use in fingertip reconstruction

OBJECTIVE

Many skin flaps have been described for fingertip reconstruction; however, they have not been compared histologically. The aim of this study is to compare the histological features of common insensate flaps that are used for fingertip reconstruction.

METHOD

Skin from fingertips and common flap donor sites on the hand and forearm of cadavers were harvested. This study investigated four histological characteristics, namely thickness of the epidermis and dermis; the ratio of collagen to elastic fibres (C/E ratio) in subdermal tissues, and distribution densities of Merkel cells and Meissner's corpuscles. It then compared the values obtained to determine which flap donor site best matched the fingertip.

RESULTS

Epidermal thickness of the reverse digital artery island flap, thenar flap, and hypothenar flap was similar to that of fingertip tissue; dermal thickness of the hypothenar flap was similar to that of fingertip tissue. The C/E ratio of the reverse digital artery island flap was similar to that of fingertip tissue. Merkel cells were abundant in the reverse digital artery island flap, but Meissner's corpuscles were few in each of the flaps compared with fingertip tissue.

CONCLUSION

The flap donor site with histological properties most similar to fingertip tissue was the palmar lateral aspect at the finger base, representative of the reverse digital artery island flap with respect to epidermal thickness, C/E ratio, and presence of Merkel cells. The thenar and hypothenar flaps also showed similar properties.

Examining the Relationships Between Bone Tissue Composition, Compositional Heterogeneity, and Fragility Fracture: A Matched Case-Controlled FTIRI Study

Fourier transform infrared imaging (FTIRI) provides information on spatial distribution of the chemical composition of thin tissue specimens at ∼7 µm spatial resolution. This study of 120 age- and bone mineral density (BMD)-matched patients was designed to investigate the association of FTIRI variables, measured in iliac crest biopsies, with fragility fractures at any site. An earlier study of 54 women found hip BMD to be a significant explanatory variable of fracture risk for cortical bone but not for cancellous bone. In the current study, where age and BMD were controlled through matching, no such association was observed, validating the pairing scheme. Our first study of unmatched iliac crest biopsies found increases in collagen maturity (cancellous and cortical bone) and mineral crystal size (cortical bone only) to be a significant explanatory variable of fracture when combined with other covariates. The ratio for collagen maturity has been correlated to the amount of enzymatic collagen cross-links. To assess the impact of other FTIRI variables (acid phosphate substitution, carbonate-to-phosphate ratio, and the pixel distribution [heterogeneity] of all relevant FTIRI variables), we examined biopsies from a matched case-controlled study, in which 60 women with fractures were each paired with an age- and BMD-matched female control. With the matched data set of 120 women, conditional logistic regression analyses revealed that significant explanatory variables of fracture were decreased carbonate-to-phosphate ratio in both cancellous (odds ratio [OR] = 0.580, 95% confidence interval [CI] 0.37-0.909, p = 0.0176) and cortical bone (OR = 0.519, 95% CI 0.325-0.829, p = 0.0061), and increased heterogeneity (broadened pixel distribution) of collagen maturity for cancellous bone (OR = 1.549, 95% CI 1.002-2.396, p = 0.0491). The observation that collagen maturity was no longer linked to fracture in age- and BMD-matched samples suggests that age-dependent variation in collagen maturity may be a more important contributory factor to fragility fractures than previously thought. © 2015 American Society for Bone and Mineral Research.

An Experimental Model Design for Photoaging

Autologous adipose-derived stem cells have shown great promise in applications that treat photodamaged skin. Adipose-derived stem cells also have an antiwrinkle effect; consequently, they have become a topic of primary interest. Nude mice have been used extensively in studies of adipose-derived stem cells, human dermal fibroblasts, and other filler injections. However, a nude mouse model of photoaging has not yet been developed. Thus, we attempted to develop a nude mouse model of photoaging in this study.

MATERIALS AND METHODS

Fourteen, 5-week-old female BALB/c nude mice were irradiated with ultraviolet-B rays, 6 times a week for 6 weeks. The minimum erythema dose was established before the mice underwent ultraviolet irradiation to minimize the inflammation of the irradiated skin and to determine the initial irradiation dosage. The mean sizes of the wrinkled areas of skin and the mean depths of the wrinkles were compared between the study groups using replica analysis. Skin biopsies were performed on the 6th and 10th weeks of the study.

RESULTS

The mean sizes of the wrinkled areas of skin and the mean depths of the wrinkles increased significantly in the ultraviolet-B-irradiated nude mice compared with the nonirradiated mice, and the thicknesses of the epidermis and dermis of the skin from the upper and lower back were significantly greater after ultraviolet-B irradiation up to the 6th week of treatment (P < 0.05). Furthermore, the ultraviolet-B-irradiated group demonstrated reduced collagen fiber levels.

CONCLUSIONS

We have successfully developed a nude mouse model for research into photoaging, and these results indicate that the nude mouse is a suitable model for investigating the development of photoaging.