Dermal penetration of creatine from a face-care formulation containing creatine, guarana and glycerol is linked to effective antiwrinkle and antisagging efficacy in male subjects

Background The dermal extracellular matrix provides stability and structure to the skin. With increasing age, however, its major component collagen is subject to degeneration, resulting in a gradual decline in skin elasticity and progression of wrinkle formation. Previous studies suggest that the reduction in cellular energy contributes to the diminished synthesis of cutaneous collagen during aging. Aims To investigate the potential of topically applied creatine to improve the clinical signs of skin aging by stimulating dermal collagen synthesis in vitro and in vivo. Patients/Methods Penetration experiments were performed with a pig skin ex vivo model. Effects of creatine on dermal collagen gene expression and procollagen synthesis were studied in vitro using cultured fibroblast‐populated collagen gels. In a single‐center, controlled study, 43 male Caucasians applied a face‐care formulation containing creatine, guarana extract, and glycerol to determine its influence on facial topometric features. Results Cultured human dermal fibroblasts supplemented with creatine displayed a stimulation of collagen synthesis relative to untreated control cells both on the gene expression and at the protein level. In skin penetration experiments, topically applied creatine rapidly reached the dermis. In addition, topical in vivo application of a creatine‐containing formulation for 6 weeks significantly reduced the sagging cheek intensity in the jowl area as compared to baseline. This result was confirmed by clinical live scoring, which also demonstrated a significant reduction in crow’s feet wrinkles and wrinkles under the eyes. Conclusions In summary, creatine represents a beneficial active ingredient for topical use in the prevention and treatment of human skin aging.     

A novel treatment option for photoaged skin

Background DNA damage as a result of ultraviolet (UV) exposure plays an important role in the progression of cutaneous aging. Both folic acid and creatine have been linked to the process of DNA protection and repair. Aims This study aims to investigate the effects of a commercially available folic acid– and creatine‐containing formulation to fight the clinical signs of premature skin aging. Patients/methods Both in vitro and in vivo home‐in‐use studies using a folic acid– and creatine‐containing formulation were performed aiming to elucidate the efficacy in terms of improvement of skin regeneration, protection from UV‐induced DNA damage (Comet assay), reduction of wrinkle volume, and skin visco‐elasticity. Furthermore, clinical evaluation and photography were carried out to determine the improvement of clinically graded parameters after treatment. Results Cultured full‐thickness epidermal skin models supplemented with folic acid and creatine after epithelial perturbation showed an accelerated skin regeneration compared to untreated control models. Similarly, application of a folic acid– and creatine‐containing formulation significantly improved epidermal turnover in vivo as evidenced by smaller corneocytes derived from the treated sites relative to the vehicle‐treated sides. In addition, topical in vivo application of this formulation significantly protected from UV‐induced DNA lesions, increased skin firmness, and reduced wrinkle volume compared to untreated control areas. Expert grading confirmed a significant decrease of fine and coarse wrinkles in the periocular region as well as overall wrinkles, tactile roughness, and laxity. Conclusions Taken together, these results show that the combination of folic acid and creatine significantly accelerates epidermal skin regeneration in vitro and in vivo. Together with the finding of improved biomechanical skin properties, we conclude that the described topical formulation provides an effective treatment option for (photo)‐aged skin.     

High-concentration all-trans retinoic acid induces dermal inflammation and reduces the accumulation of type I procollagen in human skin in vivo

Background Because inflammation is a factor promoting ageing, all‐trans retinoic acid (RA)‐induced irritation may have a negative influence on collagen accumulation in human skin despite its stimulation of collagen production. Objectives To determine whether RA‐induced irritation detrimentally affects RA efficacy as represented by new collagen synthesis. Methods Retinoic acid (0·01%, 0·025% or 0·05%) or vehicle was applied to the buttock skin of elderly male volunteers three times a week for 8 weeks under continuous occlusion. Every 2 weeks, biopsy specimens were obtained and immunohistochemical analysis was performed to determine levels of type I procollagen expression and inflammatory cell infiltration. Results Topical RA regardless of concentration increased type I procollagen expression in human skin in vivo after 2 weeks. However, only 0·01% RA continuously increased type I procollagen expression up to 8 weeks. After 4 weeks, significant infiltrations of macrophages and neutrophils were observed in 0·025% and 0·05% RA‐treated skin, and procollagen expression had returned to baseline. Conclusions Excessive RA‐induced inflammation might prevent collagen accumulation in aged skin despite the positive effect of RA on collagen production.     

Natural Arctium lappa fruit extract improves the clinical signs of aging skin

Background Subclinical, chronic tissue inflammation involving the generation of cytokines (e.g., interleukin‐6 and tumor necrosis factor‐alpha) might contribute to the cutaneous aging process. Aims This study aims to screen for an active ingredient with anti‐inflammatory (i.e., reduction of interleukin‐6 and tumor necrosis factor‐alpha) and matrix‐stimulating efficacy which improves the clinical signs of skin aging in vivo. Patients/methods In vitro studies with pure Arctiin were performed investigating the inhibition of cytokine induction and stimulation of collagen neosynthesis. In vivo home‐in‐use studies using an Arctium lappa fruit extract–containing formulation were carried out to determine procollagen and hyaluronan synthesis, hyaluronan synthase‐2 gene expression, and reduction of wrinkle volume after treatment. Results In vitro studies on human dermal fibroblasts and monocyte‐derived dendritic cells supplemented with pure Arctiin showed relative to untreated control cells a stimulation of collagen synthesis and a decrease in interleukin‐6 and tumor necrosis factor‐alpha concentration, respectively. In addition, topical in vivo application of an A. lappa fruit extract–containing formulation for 12 weeks significantly stimulated procollagen synthesis and increased hyaluronan synthase‐2 expression as well as hyaluronan levels compared to vehicle‐treated control areas. Similarly, after a 4‐week treatment with an A. lappa fruit extract–containing formulation, wrinkle volume in the crow's feet area was significantly reduced as compared to treatment with the vehicle. Conclusions Our data show that topical treatment with a natural A. lappa fruit extract significantly improves the metabolism of the dermal extracellular matrix and leads to a visible wrinkle reduction in vivo. In conclusion, A. lappa fruit extract represents a targeted means to regenerate dermal structures and, thus, offers an effective treatment option for mature skin.     

A three‐dimensional skin equivalent reflecting some aspects of in vivo aged skin

Human skin undergoes morphological, biochemical and functional modifications during the ageing process. This study was designed to produce a 3‐dimensional (3D) skin equivalent in vitro reflecting some aspects of in vivo aged skin. Reconstructed skin was generated by co‐culturing skin fibroblasts and keratinocytes on a collagen–glycosaminoglycan–chitosan scaffold, and ageing was induced by the exposition of fibroblasts to Mitomycin‐C (MMC). Recently published data showed that MMC treatment resulted in a drug‐induced accelerated senescence (DIAS) in human dermal fibroblast cultures. Next to established ageing markers, histological changes were analysed in comparison with in vivo aged skin. In aged epidermis, the filaggrin expression is reduced in vivo and in vitro. Furthermore, in dermal tissue, the amount of elastin and collagen is lowered in aged skin in vivo as well as after the treatment of 3D skin equivalents with MMC in vitro. Our results show histological signs and some aspects of ageing in a 3D skin equivalent in vitro, which mimics aged skin in vivo.     

Heat shocks enhance procollagen type I and III expression in fibroblasts in ex vivo human skin

Background: The well‐known characteristics of aging skin are the development of fine lines and wrinkles, but changes in skin tone, skin texture, thickness and moisture content are also aspects of aging. Rejuvenation of the skin aims at reversing the signs of aging and can be established in the epidermis as well as in the dermis. Aged dermis, in fact, has a degenerated collagen matrix. To regenerate this matrix, fibroblasts need to be stimulated into synthesizing new collagen. Aims: In this study, the effects of heat shocks of different temperatures on human dermal fibroblasts in ex vivo skin on the expression of procollagen 1, procollagen 3, heat shock protein (hsp)27, hsp47, and hsp70 are investigated. Materials and methods: The heat shocks were applied on ex vivo skin samples by immersing the samples in heated phosphate‐buffered saline of 45 °C or 60 °C. Metabolic activity was measured and at similar time points propidium–iodide–calceine staining was performed to establish cell viability. Quantitative polymerase chain reaction (qPCR) was performed after the heat shock to determine gene expression levels relative to the reference temperature. Furthermore, PicroSirius Red and hematoxylin stainings were performed to visualize the collagen network and the cells. Results: The skin samples were shown to be viable and metabolically active. Histology indicated that the heat shocks did not influence the structure of the collagen network or cell appearance. qPCR results showed that in contrast to the 45 °C heat shock the 60 °C heat shock resulted in significant upregulations of procollagen type I and III, hsp70 and hsp47. Conclusion: A 60 °C, heat shock stimulates the human dermal fibroblasts in ex vivo skin to upregulate their procollagen type I and type III expression.     

Dietary compound ellagic acid alleviates skin wrinkle and inflammation induced by UV‐B irradiation

Please cite this paper as: Dietary compound ellagic acid alleviates skin wrinkle and inflammation induced by UV‐B irradiation. Experimental Dermatology 2010; 19 : e182–e190. Abstract: Ellagic acid, a polyphenol compound present in berries and pomegranate, has received attention as an agent that may have potential bioactivities preventing chronic diseases. This study examined photoprotective effects of ellagic acid on collagen breakdown and inflammatory responses in UV (ultraviolet)‐B irradiated human skin cells and hairless mice. Ellagic acid attenuated the UV‐B‐induced toxicity of HaCaT keratinocytes and human dermal fibroblasts. Non‐toxic ellagic acid markedly prevented collagen degradation by blocking matrix metalloproteinase production in UV‐B‐exposed fibroblasts. Anti‐wrinkle activity of ellagic acid was further investigated in hairless mice exposed to UV‐B, in which it attenuated UV‐B‐triggered skin wrinkle formation and epidermal thickening. Topical application of 10 μmol/l ellagic acid diminished production of pro‐inflammatory cytokines IL‐1β and IL‐6, and blocked infiltration of inflammatory macrophages in the integuments of SKH‐1 hairless mice exposed to UV‐B for 8 weeks. In addition, this compound mitigated inflammatory intracellular cell adhesion molecule‐1 expression in UV‐B‐irradiated keratinocytes and photoaged mouse epidermis. These results demonstrate that ellagic acid prevented collagen destruction and inflammatory responses caused by UV‐B. Therefore, dietary and pharmacological interventions with berries rich in ellagic acid may be promising treatment strategies interrupting skin wrinkle and inflammation associated with chronic UV exposure leading to photoageing.     

Three clinical studies showing the anti-aging benefits of sodium salicylate in human skin

Background Anti‐aging effects of high concentrations of salicylic acid (SA) peels are commonly known. Like all acids, SA can produce somatosensory and visible irritation to the skin and as such may be unsuitable for subjects with sensitive skin. Aims To provide evidence that sodium salicylate (SS) obtained from neutralization of 1% SA by sodium hydroxide can deliver significant anti‐aging benefits. Methods The effects of SS were examined using three approaches: (1) evaluating its effects on stimulating the synthesis of fibrillin and collagen‐1 in vivo; (2) examining its efficacy by using Fast Optical in vivo Topometry (FOITS) in a double‐blind, placebo‐controlled clinical study; (3) determining its effects on both expert and naïve grader assessement of wrinkles in a double‐blind, placebo‐controlled study. Results In the first study SS produced significant increases of the fibrillin and collagen‐1 anti‐aging biomarkers compared with the untreated skin control. A commercially available retinol cream delivered similar effects to SS. In the second study using FOITS we showed that the SS formulation significantly reduced wrinkle depth (Rz) and skin roughness (Ra) after 4 and 8 weeks of daily application vs. placebo (Rz: ?8.2 ± 1.40% and ?11.4 ± 1.07%; Ra: ?7.8 ± 1.33% and ?11.9 ± 0.61%; P < 0.01). In the third study reductions in wrinkle depth were observed by expert assessment at both 4 and 8 weeks for the SS‐containing formulation compared to its placebo (P < 0.05). Equally, non‐expert graders recorded the SS formulation superior to its placebo. Conclusion Although the mechanism of action is not completely understood, we believe the benefits of SS are derived from its intrinsic stratum corneum exfoliation effects. All three studies demonstrate the significant anti‐aging effects of SS that are especially suitable for subjects with sensitive skin.     

Topical mometasone furoate and betamethasone-17-valerate decrease collagen synthesis to a similar extent in human skin in vivo

Topical corticosteroids are used extensively to treat inflammatory skin diseases. Long-term use, however, may be associated with adverse effects such as skin atrophy. New steroids have been developed with the objective of increasing efficacy and reducing the incidence of adverse effects. Mometasone furoate (MMF) is one of these new derivatives. The aim of our study was to compare the effects of MMF and betamethasone-17-valerate (BM-17-valerate) on collagen synthesis in human skin in vivo. Fifteen healthy male volunteers applied MMF, BM-17-valerate and vehicle for 1 week to different areas of abdominal skin. Suction blisters were raised on these areas, and a control site, and procollagen propeptide (PICP, PINP, PIIINP) levels in the suction blister fluid were measured by radioimmunoassay. Skin thickness was measured ultrasonically by Dermascan A at the end of the treatment period. The levels of the three propeptides in suction blister fluid were reduced to a similar extent by MMF and BM-17-valerate. The 1-week treatment period had no detectable influence on skin thickness. We conclude that MMF and BM-17-valerate decrease collagen synthesis to the same extent in human skin in vivo.     

Morphological skin ageing criteria by multiphoton laser scanning tomography: non-invasive in vivo scoring of the dermal fibre network

Background: Morphological changes in the dermal collagen and elastin fibre network are characteristic for skin ageing and for pathological skin conditions of the dermis. Objectives: To characterize pathological and physiological conditions by multiphoton laser scanning tomography (MLT) in vivo, it is necessary to investigate and identify morphological alterations related to ageing. Methods: In vivo MLT was used to image two‐photon excited autofluorescence (AF) and second harmonics generation (SHG) in human dermis of 18 volunteers of different ages. Criteria for the evaluation of age‐dependent morphological changes in MLT images were fibre tension and morphology, network pattern, clot formation and image homogeneity. These criteria were weighted and a score was calculated. Results: The resulting MLT‐based Dermis Morphology Score is correlated with age (R² = ?0.90) and with the previously published SHG to AF Ageing Index of Dermis (R² = 0.66). The two groups of young (age 21–38) and old (age 66–84) volunteers showed a significant difference in MLT score values (P < 0.001). Conclusions: We could demonstrate an in vivo relationship between morphological characteristics of human dermis assessed by MLT and age. The present score allows the semi‐quantitative evaluation of specific morphological changes of the dermal fibre network in ageing skin by in vivo AF and SHG imaging. This method will be useful for diagnostics of pathological conditions and their differentiation from ageing effects.     

Bleomycin‐induced fibrosis in MC1 signalling‐deficient C57BL/6J‐Mc1re/e mice further supports a modulating role for melanocortins in collagen synthesis of the skin

The melanocortin‐1 receptor (MC₁) binds α‐melanocyte‐stimulating hormone (α‐MSH) with high affinity and has a physiological role in cutaneous melanin pigmentation. Previously, we reported that human dermal fibroblasts also express functional MC₁. α‐MSH suppressed transforming growth factor‐β₁‐ and bleomycin (BLM)‐induced collagen synthesis in vitro and in vivo. Using MC₁ signalling‐deficient C57BL/6J‐Mc1r^e/e mice, we tested as to whether MC₁ has a regulatory role on dermal collagen synthesis in the BLM model of scleroderma. Notably, mice with a C57BL/6J genetic background were previously shown to be BLM‐non‐susceptible. Interestingly, treatment of C57BL/6J‐Mc1r^e/e but not of C57BL/6J‐wild‐type mice with BLM increased cutaneous collagen type I content at RNA and protein level along with development of skin fibrosis. Cutaneous levels of connective tissue growth factor and monocyte chemotactic protein‐1 were also increased in BLM‐treated C57BL/6J‐Mc1r^e/e mice. Primary dermal fibroblasts from C57BL/6J‐wt mice further expressed MC₁, suggesting that these cells are directly targeted by melanocortins to affect collagen production of the skin. Our findings support the concept that MC₁ has an endogenous regulatory function in collagen synthesis and controls the extent of fibrotic stress responses of the skin.     

Prostaglandin E2 inhibits collagen synthesis in dermal fibroblasts and prevents hypertrophic scar formation in vivo

Hypertrophic scarring is a common dermal fibroproliferative disorder characterized by excessive collagen deposition. Prostaglandin E₂ (PGE₂), an important inflammatory product synthesized via the arachidonic acid cascade, has been shown to act as a fibroblast modulator and to possess antifibroblastic activity. However, the mechanism underlying the antifibrotic effect of PGE₂ remains unclear. In this study, we explored the effects of PGE₂ on TGF‐β1‐treated dermal fibroblasts in terms of collagen production and to determine the regulatory pathways involved, as well as understand the antiscarring function of PGE₂ in vivo. We found that PGE₂ inhibited TGF‐β1‐induced collagen synthesis by regulating the balance of matrix metalloproteinases (MMPs) and tissue inhibitor of metalloproteinase (TIMP). It did so by upregulating cAMP through the E prostanoid (EP)2 receptor. We determined that inhibition of the TGF‐β1/Smad pathway by PGE₂ is associated with its ability to inhibit collagen synthesis. An in vivo study further confirmed that PGE₂ inhibits hypertrophic scar formation by decreasing collagen production. Our results demonstrate that the novel anti‐scarring function of PGE₂ is achieved by balancing MMPs/TIMP expression and decreasing collagen production.     

Dermal delivery by niosomes of black tea extract as a sunscreen agent

Objectives  The primary objective of this study was to investigate the feasibility of using niosomes as a delivery vehicle for the dermal administration in vitro of black tea extract (BTE) as a sunscreen. Methods  Multi‐lamellar niosomes were obtained by means of a previously reported method of lipid hydration films. In vitro penetration experiments through nude mouse skin were carried out to evaluate the potential of niosomes as a dermal formulation. The nude mouse skin membrane allowed the effects of penetration with a niosome formulation to be evaluated. Penetration rates of caffeine‐ and gallic acid‐loaded niosomes in a steady state were higher than dispersion in aqueous solutions. Results  For skin permeation, higher transdermal absorption rates were seen with solutions of caffeine and gallic acid. Conclusions  In the near future, BTE as a sunscreen agent will be dermally delivered by niosomes.     

Effect of cosmetic ingredients as anticellulite agents: synergistic action of actives with in vitro and in vivo efficacy

Background The pathophysiology of cellulite involves changes in the subcutaneous adipose layer and the extracellular matrix (ECM) that supports it together with overlying dermal layer. Cellular mechanisms governing cellulite are not fully understood. However, it is accepted that changes include enhanced lipogenesis, decreased lipolysis, and increased lipid storage within the adipocytes as well as changes in the dermal architecture. Aim In our studies the ability of cosmetic agents Furcellaria lumbricalis, Fucus vesiculosus, retinoid, conjugated linoleic acid (CLA), and a glaucine mixture to stimulate in vitro1) lipolysis in human adipocytes and 2) production of pro‐collagen I by fibroblasts was investigated in vitro. The ability of these ingredients to improve cellulite condition in vivo was also determined. Patients/Methods Mature adipocytes and 'aged' fibroblasts were used for in vitro studies. The assessment of cellulite in vivo was performed by dermatological grading and ultrasound measurements. Results Mature adipocytes treated with combined actives resulted in a significant synergistic increase in free glycerol release. On “aged” fibroblasts, combined treatment of F. vesiculosus and F. lumbricalis stimulated pro‐collagen I production. CLA increased pro‐collagen I production, but the glaucine mixture had no effect. The clinical study demonstrated a significant improvement in cellulite grading by a dermatologist after 8 and 12 weeks vs. vehicle, and ultrasound imaging showed a significant decrease in fat thickness compared with placebo after 12 weeks. Conclusions Our studies revealed a potent cocktail of ingredients that when combined together can act in vitro to markedly improve lipolysis mechanisms and by way of stimulating pro‐collagen I can also have an effect on the surrounding extracellular matrix. The in vitro actions of the ingredients were translated in vivo, where a clinical improvement of cellulite condition was observed.     

Retinoids suppress cysteine-rich protein 61 (CCN1), a negative regulator of collagen homeostasis, in skin equivalent cultures and aged human skin in vivo

Alterations in connective tissue collagen are prominent features of both chronologically aged and photoaged (ageing because of sun exposure) human skin. These age-related abnormalities are mediated in part by cysteine-rich protein 61 (CCN1). CCN1 is elevated in the dermis of both chronologically aged and photoaged human skin in vivo and promotes aberrant collagen homeostasis by down-regulating type I collagen, the major structural protein in skin, and promoting collagen degradation. Vitamin A and its metabolites have been shown to improve chronologically aged and photoaged skin by promoting deposition of new collagen and preventing its degradation. Here, we investigated regulation of CCN1 expression by retinoids in skin equivalent cultures and chronologically aged and photoaged human skin in vivo. In skin equivalent cultures, all-trans retinoic acid (RA), the major bioactive form of vitamin A in skin, significantly increased type I procollagen and reduced collagenase (matrix metalloproteinases-1, MMP-1). Addition of recombinant human CCN1 to skin equivalent cultures significantly reduced type I procollagen and increased MMP-1. Importantly, RA significantly reduced CCN1 expression in skin equivalent cultures. Topical treatment with retinol (vitamin A, 0.4%) for 7days significantly reduced CCN1 mRNA and protein expression in both chronologically aged (80+years) and photoaged human skin in vivo, compared to vehicle-treated skin. These data indicate that the mechanism by which retinoids improve aged skin, through increased collagen production, involves down-regulation of CCN1.     

Fermentable metabolite of <Emphasis Type="Italic">Zymomonas mobilis</Emphasis> controls collagen reduction in photoaging skin by improving TGF-β/Smad signaling suppression

Solar ultraviolet (UV) irradiation causes damages on human skin and premature skin aging (photoaging). UV-induced reduction of type I collagen in dermis is widely considered primarily induction of wrinkled appearance of photoaging skin. Type I procollagen synthesis is reduced under UV irradiation by blocking transforming growth factor-β (TGF-β)/Smad signaling; more specifically, it is down-regulation of TGF-β type II receptor (TβRII). Therefore, preventing UV-induced loss of TβRII results decreased type I collagen reduction in photoaging skin. Zymomonas mobilis is an alcohol fermentable, gram-negative facultative anaerobic bacterium whose effect on skin tissue is scarcely studied. We investigated the protective effects of fermentable metabolite of Z. mobilis (FM of Z. mobilis) against reduction of type I procollagen synthesis of UV-induced down-regulation of TβRII in human dermal fibroblasts FM of Z. mobilis was obtained from lyophilization of bacterium culture supernatant. The levels of TβRII and type I procollagen mRNA in human dermal fibroblasts were measured by quantitative real-time RT-PCR, and TβRII protein levels were assayed by western blotting. TβRII, type I procollagen, and type I collagen proteins in human dermal fibroblasts or hairless mouse skin were detected by immunostaining. FM of Z. mobilis inhibited down regulation of TβRII mRNA, and protein levels in UVB irradiated human dermal fibroblasts consequently recover reduced type I procollagen synthesis. These results indicate UVB irradiation inhibits type I procollagen synthesis by suppression of TGF-β/Smad signaling pathway, and FM of Z. mobilis has inhibitory effect on UVB-induced reduction of type I procollagen synthesis. While short period UVB irradiation decreased both TβRII and type I procollagen protein levels in hairless mouse skin, topical application of FM of Z. mobilis prevented this decrease. Wrinkle formation in hairless mouse skin surface was accelerated by continuous 5 month UVB irradiation along with a reduction of type I collagen in the dermis, but this change was prevented by topical application of FM of Z. mobilis. From this experimental data, it is suggested that FM of Z. mobilis is effective for suppression of wrinkle formation in photoaging skin by inhibition of type I procollagen synthesis reduction.     

Improvement of the dermal epidermal junction in human reconstructed skin by a new c-xylopyranoside derivative

Skin aging entails drastic changes in the extracellular dermal matrix (ECM) and dermal-epidermal junction (DEJ). These biological alterations are reflected in the clinical signs of aged skin. A new C-xylopyranoside derivative, C-beta-D-xylopyranoside-2-hydroxy-propane (C-Xyloside) has been shown to induce neo-synthesis of matrix proteins such as glycosaminoglycans and heparan sulfate proteoglycans. The aim of this study was to assess the effects of C-Xyloside on markers of the dermal epidermal junction. Basement membrane components, collagen IV, collagen VII and laminin 5 as well as sub-epidermal dermal markers, pro-collagen I and fibrillin 1 were analysed using immunohistochemistry in a reconstructed skin model, including a dermal equivalent populated with living fibroblasts. Levels of mRNA of collagen VII alpha1 and collagen IV alpha1 were evaluated in dermal fibroblasts using RT-PCR. The results showed that C-Xyloside significantly induced a higher deposition of basement membrane and DEJ proteins in the reconstructed skin model and increased collagen VII gene expression. These findings indicate that, in addition to stimulating glycosaminoglycan and heparan sulfate proteoglycan expression, C-Xyloside improves the morphogenesis of the whole DEJ, and strongly suggests beneficial effects in aged skin from restoring DEJ integrity.     

Morphogenesis of chimeric hair follicles in engineered skin substitutes with human keratinocytes and murine dermal papilla cells

Engineered skin substitutes (ESS) have been used successfully to treat life‐threatening burns, but lack cutaneous appendages. To address this deficiency, dermal constructs were prepared using collagen‐glycosaminoglycan scaffolds populated with murine dermal papilla cells expressing green fluorescent protein (mDPC‐GFP), human dermal papilla cells (hDPC) and/or human fibroblasts (hF). Subsequently, human epidermal keratinocytes (hK) or hK genetically modified to overexpress stabilized β‐catenin (hK') were used to prepare ESS epithelium. After 10 days incubation at air–liquid interface, ESS were grafted to athymic mice and were evaluated for 6 weeks. Neofollicles were observed in ESS containing mDPC‐GFP, but not hDPC or hF, independent of whether or not the hK were genetically modified. Based on detection of GFP fluorescence, mDPC were localized to the dermal papillae of the well‐defined follicular structures of grafted ESS. In addition, statistically significant increases in LEF1, WNT10A and WNT10B were found in ESS with neofollicles. These results demonstrate a model for generation of chimeric hair in ESS.     

Molecular interactions of plant oil components with stratum corneum lipids correlate with clinical measures of skin barrier function

Plant‐derived oils consisting of triglycerides and small amounts of free fatty acids (FFAs) are commonly used in skincare regimens. FFAs are known to disrupt skin barrier function. The objective of this study was to mechanistically study the effects of FFAs, triglycerides and their mixtures on skin barrier function. The effects of oleic acid (OA), glyceryl trioleate (GT) and OA/GT mixtures on skin barrier were assessed in vivo through measurement of transepidermal water loss (TEWL) and fluorescein dye penetration before and after a single application. OA's effects on stratum corneum (SC) lipid order in vivo were measured with infrared spectroscopy through application of perdeuterated OA (OA‐d₃₄). Studies of the interaction of OA and GT with skin lipids included imaging the distribution of OA‐d₃₄ and GT ex vivo with IR microspectroscopy and thermodynamic analysis of mixtures in aqueous monolayers. The oil mixtures increased both TEWL and fluorescein penetration 24 h after a single application in an OA dose‐dependent manner, with the highest increase from treatment with pure OA. OA‐d₃₄ penetrated into skin and disordered SC lipids. Furthermore, the ex vivo IR imaging studies showed that OA‐d₃₄ permeated to the dermal/epidermal junction while GT remained in the SC. The monolayer experiments showed preferential interspecies interactions between OA and SC lipids, while the mixing between GT and SC lipids was not thermodynamically preferred. The FFA component of plant oils may disrupt skin barrier function. The affinity between plant oil components and SC lipids likely determines the extent of their penetration and clinically measurable effects on skin barrier functions.     

The effect of Zanthoxylum bungeanum maxim extract on crow's feet: A double‐blind,split‐face trial

As one of the most obvious signs of aging, wrinkles have long been the concern of many people and continue to be a major topic in dermal‐cosmetic industry. Accordingly, there is a need to develop products with good efficacy and safety profile. The Zanthoxylum bungeanum maxim (ZBM) extract is a natural food which may possess the property of a toxin‐like botulinum. To evaluate the efficacy and safety of a formulation that contains 2% ZBM pericarp extract in the treatment of wrinkles. Twenty females aged 35–60 years old were enrolled in this randomized, vehicle‐controlled, double‐blind, and split‐face trial. The trial lasted for 30 days, when participants randomly used formulations containing 2% ZBM extract on one side of the temporal canthus and vehicle formulation on the other side. Skin roughness, skin hydration, and skin elasticity were evaluated by Primospico, Corneometer® CM825, and Cutometer® MPA580, respectively. The formulation containing 2% ZBM extract has a significant short‐term anti‐crow's feet effect compared with vehicle. No adverse effect was shown during the study. Topical application of 2% ZBM extract is tolerable and can be used as an effective cosmetic agent for short‐term wrinkle treatment.