Daily Ingestion of Aloe Vera Gel Powder Containing Aloe Sterols Prevents Skin Photoaging in OVX Hairless Mice

Estrogen deficiencies associated with menopause accelerate spontaneous skin aging and stimulate the ultraviolet (UV) irradiation‐induced photoaging of skin. However, food compositions with the potential to ameliorate the UV irradiation‐induced acceleration of skin aging with menopause have not yet been investigated in detail. In the present study, we examined the ability of plant sterols derived from Aloe vera gel to prevent the UV irradiation‐induced acceleration of skin aging in ovariectomized mice. Skin transepidermal water loss (TEWL) was significantly higher in the ovariectomy group than in the sham operation group following UVB irradiation, whereas skin elasticity was significantly lower. Ultraviolet B (UVB) irradiation induced greater reductions in skin hyaluronic acid levels and more severe collagen fiber damage in the derims in the ovariectomy group than in the sham group. The intake of AVGP significantly ameliorated this acceleration in skin aging by reducing the expression of matrix metalloproteinases (MMPs) and increasing that of epidermal growth factor (EGF) and hyaluronan synthase (HAS) in the skin. These results indicate that AVGP supplementation prevents skin damage induced by UVB irradiation and ovariectomy in part by inhibiting damage to the extracellular matrix.     

A novel anti‐ageing mechanism for retinol: induction of dermal elastin synthesis and elastin fibre formation

Dermal elastic fibres are extracellular matrix protein complexes produced by fibroblasts and involved in skin elasticity. Elastin fibres decrease with age as a result of reduced synthesis and increased degradation, resulting in skin sagging and reduced skin elasticity. In this study, we show that retinol (ROL), known to enhance dermal collagen production, is also enhancing elastin fibre formation. ROL induced elastin gene expression and elastin fibre formation in cultured human dermal fibroblasts. Topical treatment of cultured human skin explants with a low dose (0.04%) of ROL increased mRNA and protein levels of tropoelastin and of fibrillin‐1, an elastin accessory protein, as documented by QPCR and immunohistochemistry staining. Luna staining confirmed the increased elastin fibre network in the ROL‐treated skin explants, as compared with untreated controls. These data demonstrate that ROL exerts its anti‐ageing benefits not only via enhanced epidermal proliferation and increased collagen production, but also through an increase in elastin production and assembly.     

The effect of pacific cod (Gadus macrocephalus) skin gelatin polypeptides on UV radiation-induced skin photoaging in ICR mice

Gelatin was extracted from Pacific cod (Gadus macrocephalus) skin and hydrolysed sequentially with pepsin and alkaline protease. The hydrolysates were fractionated into two ranges of molecular weight (PEP1: 2000 Da < Mr < 6000 Da; PEP2: Mr < 2000 Da) using ultrafiltration membranes. In this present study, we investigate the protective effects of both polypeptides against ultraviolet radiation-induced skin photoaging by the activity of superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), catalase (CAT) and the contents of glutathione (GSH), malondialdehyde (MDA), hydroxyproline (HYP) in photoaging skin tissue. The arrangement of collagen fibres in skin tissue was examined by Van Gienson stain. UV radiation-induced decrease in the antioxidase activity and depletion of reduced glutathione (20.4%) in the skin of hairless mice in a model group. Compared with the model, both polypeptides can enhance the activities of SOD, GSH-Px, CAT and the contents of GSH and HYP, and reduce the content of MDA, which minimised the skin photo damage. Moreover, the results of histology study confirmed that both polypeptides could protect collagen fibres in skin.     

Preventive effect of fermented Gelidium amansii and Cirsium japonicum extract mixture against UVB-induced skin photoaging in hairless mice

Chronic ultraviolet (UV) light causes skin photoaging, characterized by fine and coarse wrinkle formation and dryness. In this study, the effect of fermented Gelidium amansii and Cirsium japonicum extract mixture (FGCM) with lactic acid bacteria on UVB-induced photoaging was evaluated in human dermal fibroblasts and SKH-1 hairless mice. In vitro, FGCM increased type I procollagen levels and suppressed UVB-induced matrix metalloproteinase-1 (MMP-1) expression more effectively than G. amansii and C. japonicum extract mixture (GCM). In vivo, oral administration of FGCM significantly inhibited UVB-induced the number and total depth of wrinkles in the dorsal skin of mice. FGCM suppressed UVB-induced epidermal thickening, and attenuated UVB-induced MMP-13 expression and MMP-2 and MMP-9 activities in dermal tissue. Furthermore, FGCM increased skin hydration and blocked transepidermal water loss in the dorsal skin of mice compared with the UVB-irradiated group. These data indicate that FGCM exerts potent anti-photoaging activities by improving wrinkle formation and dryness.     

Sodium dl-α-tocopheryl phosphate inhibits ultraviolet-induced production of reactive nitrogen species in human keratinocytes

The phenomenon of aging can broadly be categorized into photoaging caused by exogenous factors and physiological aging that is caused by endogenous factors. Our goal was to develop a non-invasive way to assess changes taking place inside the skin for each type of aging, photoaging and physiological aging, by using near-infrared diffuse reflectance (NIR-DR) spectroscopy. For the photoaging and physiological aging effects, the outer forearm (sun-exposed) and the inner upper arm (sun-protected) skin areas were studied in eighty-six females from twenty-three to sixty-nine years of age. Measurements were made using NIR-DR and subjected to Principal Component Analysis (PCA); the results suggested the possibility of distinguishing and quantifying both types of aging taking place inside the skin by using the 1670–1820 nm and 2000–2230 nm regions of NIR-DR spectra. In photoaging, structural changes in proteins occur which are reflected in the NIR-DR spectra in the form of a peak shift near 2050 nm that is due to a combination of amide A and amide II. On the other hand, physiological aging is associated with a change in collagen quantity as is reflected in the portion of the NIR-DR spectra assigned to protein. Using NIR-DR and PCA, we discovered the possibility of using a non-invasive method for assessing the degree of photoaging and physiological aging as degeneration and degradation.
Key words:  photoaging, physiological aging, non-invasive, NIR-DR, PCA, peak shift, a combination of amide A and amide II, protein, degeneration, degradation.     

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.     

黄酮类物质对皮肤光损伤保护的研究进展

长期过量的紫外线辐射会导致一系列的皮肤疾病,包括光老化、非黑色素瘤以及黑色素瘤皮肤癌。黄酮类化合物如橙皮苷、黄芩苷、矢车菊素-3-O-葡萄糖苷、水飞蓟宾等是广泛存在于植物中的酚类物质,研究表明黄酮类化合物可以有效预防紫外线引起的各种光损伤。本文综述了黄酮类化合物通过抗炎症、氧化应激、DNA损伤以及细胞外基质的异常合成和降解来减轻紫外线引起的光损伤作用,并且讨论了它们的具体保护作用机制,为预防皮肤光损伤和开发新的黄酮类物质的保健和防晒产品提供参考。     

中波紫外线致皮肤光老化机制及茶叶抗光老化作用研究进展

过量的紫外线照射会引起皮肤的光老化,其中以中波紫外线生物学效应最为明显。皮肤的光老化会导致皮肤临床上和组织学上的多种病变,包括胶原蛋白减少、皮肤变硬、皮层变薄、色素沉积等,并会引起日光性皮炎等多种皮肤相关疾病。中波紫外线诱导皮肤光老化的原因很多,其中最重要的原因是丝裂原活化蛋白激酶(mitogen activated protein kinase,MAPK)通路被激活,引起金属基质蛋白酶(matrix metalloproteinase,MMPs)分泌量增加导致细胞间基质被分解。茶叶作为广为人知的保健饮品,其在抗皮肤光老化方面的作用已得到了证实。茶叶水提物可以通过抑制MAPK磷酸化的途径来预防中波紫外线所致的皮肤光老化症状。文中还对该领域现有研究存在的不足进行了分析,旨在为下一步更全面深入的研究提供研究参考。     

鸡卵清白蛋白多肽抗皮肤光老化的功能研究

本文以昆明小鼠和鸡卵清白蛋白多肽为研究对象,研究了鸡卵清白蛋白多肽对紫外线损伤的小鼠光老化皮肤的保护作用。实验动物随机分为正常对照组、模型对照组、Vc阳性对照组、卵清白蛋白多肽低剂量组、卵清白蛋白多肽高剂量组五组。除正常对照组外,运用紫外灯管模拟紫外线长期照射各组小鼠皮肤的无毛部分,建立小鼠皮肤光老化模型。同时,用5％Vc溶液、10％的鸡卵清白蛋白多肽溶液、40％的鸡卵清白蛋白多肽溶液分别外涂于Vc阳性对照组、卵清白蛋白多肽低剂量组、卵清白蛋白多肽高剂量组小鼠背部无毛皮肤,正常对照组和模型对照组涂抹蒸馏水。60天后,观察各组小鼠皮肤的表观特征并测定相关生化指标。结果显示,与模型对照组相比,鸡卵清白蛋白多肽高、低剂量组小鼠皮肤光滑,褶皱较浅,富有弹性,红斑极少,接近正常对照组小鼠皮肤;皮肤重量均显著降低（p〈0．01,p〈0．01）,羟脯氨酸（HPY）含量均显著降低（p〈0．01,p〈0．05）,丙二醛（MDA）含量存在显著差异（p〈0．05,p〈0．05）,超氧化物歧化酶（SOD）活力显著增强（p〈0．05,p〈0．05）。说明鸡卵清白蛋白多肽对小鼠光老化皮肤有明显的保护作用。     

Elastin structure and its involvement in skin photoageing

Skin aging is a complex process that may be caused by factors that are intrinsic and extrinsic to the body. Ultraviolet (UV) radiation represents one of the main sources of skin damage over the years and characterizes a process known as photoaging. Among the changes that affect cutaneous tissue with age, the loss of elastic properties caused by changes in elastin production, increased degradation and/or processing produces a substantial impact on tissue esthetics and health. The occurrence of solar elastosis is one of the main markers of cutaneous photoaging and is characterized by disorganized and non‐functional deposition of elastic fibers. The occurrence of UV radiation‐induced alternative splicing of the elastin gene, which leads to inadequate synthesis of the proteins required for the correct assembly of elastic fibers, is a potential explanation for this phenomenon. Innovative studies have been fundamental for the elucidation of rarely explored photoaging mechanisms and have enabled the identification of effective therapeutic alternatives such as cosmetic products. This review addresses cutaneous photoaging and the changes that affect elastin in this process.     

Adaptive antioxidant response and photoaging

As the skin is always in contact with oxygen and is increasingly exposed to environmental and artificial ultraviolet (UV) irradiation the risk of photooxidative damage induced by reactive oxygen species – finally leading to phototoxicity, photoaging and skin cancer – has increased substantially. The term reactive oxygen species (ROS) includes oxygen centered radicals like the superoxide anion radical and the hydroxyl radical, but also non‐radical species such as hydrogen peroxide and singlet oxygen – all being produced in skin upon UV irradiation. In response to the attack of reactive oxygen species the skin has developed a complex antioxidant defense system including enzymatic and non‐enzymatic antioxidants. As a first line of the enzymatic antioxidative defense, superoxide dismutases reduce superoxide anion radicals to hydrogen peroxide which subsequently is detoxified to water by catalase and glutathione peroxidases. We were interested whether the antioxidant enzymes manganese superoxide dismutase (SOD2) and glutathion peroxidase (GPx1) are inducible upon UV irradiation and whether repetitive UV exposure, as practiced for the light‐hardening during phototherapy of photodermatoses, can even enhance the adaptive antioxidant response. To address this question skin fibroblasts and keratinocytes were exposed in vitro to single and repetitive UV low dose irradiation in different time intervals and afterwords challenged by high dose irradiation. The antioxidant response was measured in terms of steady state mRNA levels and activity changes of SOD2 or GPx1 as well as of the viability after challenge with high dose UV‐irradiation. Interstingly, only UVA but not UVB irradiation was able to induce the mRNA steady state levels and the activity of SOD2 in fibroblasts. However, fibroblasts incubated with the supernatants from UVB‐irradiated epidermal cells responded with an increase in SOD2. This increase on mRNA and activity levels was mediated by paracrine acting secreted factors produced by the keratinocytes. If fibroblasts were exposed repetitively to sublethal UVA doses the further up‐regulation of SOD2 correlated with the protection against high UV doses. Importantly, SOD2 basal levels of protein content and activity substantially differed within cultivated cells and skin biopsies from different individuals. These results provide evidence for an adaptive antioxidative UV response of the skin. Interindividual differences might account for differences in the susceptibility to develop photodermatologic disorders related to photosensitivity, photoaging, and skin cancer.     

鳕鱼皮胶原蛋白肽果汁饮料抗紫外线照射引起的皮肤光老化

为研究鳕鱼皮胶原蛋白肽果汁饮料(CJD)对紫外线诱导的皮肤光老化的调节作用,将ICR雄性小鼠随机分为正常组(NC)、模型组(MC)、CJD低剂量组(CJD-L)、中剂量组(CJD-M)和高剂量组(CJD-H),通过观察各组小鼠造模部位皮肤的表观特征、结合HE染色,皮肤中羟脯氨酸和水分的含量来评价CJD对小鼠皮肤光老化的防护作用;通过测定小鼠皮肤组织和血清中的总超氧化物歧化酶(T-SOD)、过氧化氢酶(CAT)和谷胱甘肽过氧化物酶(GSH-Px)的活力,丙二醛(MDA)的含量,来探究CJD对皮肤光老化的作用途径。结果显示,与MC组相比,CJD中剂量和高剂量组可以显著抑制光老化小鼠皮肤中水分的流失(p<0.05)及胶原含量的降低(p<0.01),显著提高小鼠皮肤组织和血清中T-SOD、GSH-Px、CAT的活力(p<0.05),显著降低MDA的含量(p<0.05)。研究表明,胶原蛋白肽饮料对紫外线引起的皮肤光老化有保护作用,能够有效预防和延缓光老化。     

Oat-based complex stimulates skin barrier protein synthesis and reduces skin ageing

Citation: IFSCC Magazine , 11 (2008) (3) 225–229
The dermis is considered a highly dynamic structure that determines the biomechanical properties of the skin. It is composed of two dermal compartments separated by a vascular plexus: the papillary dermis and the reticular dermis. In the last few years, several studies have demonstrated the role of the dermal epidermal junction in the cutaneous ageing process. Recently, teams specialized in the study of the dermal matrix have focused their studies on the superior dermis in close contact with the dermal epidermal junction: the papillary dermis. They defined the role of matrix proteins in this area. Collagens XII and XVI, non-fibrillar collagens specific to the papillary dermis, are responsible for skin deformability and extensibility. Oxytalan fibres are related to elastic properties of the skin. Ubiquitous collagens such as collagens I and VI are associated with the cohesion and the resistance of the dermis. As the papillary dermis is the primary site of intrinsic dermal ageing, we studied expression of these molecules in our own in vitro model of intrinsic ageing of the papillary dermis. The results of this innovative approach confirmed that their expression was reduced. Nevertheless, active molecules may exist in nature that are capable of restoring a normal expression profile of these markers for a cosmetic anti-ageing application.
Keywords:  Anti-ageing, papillary dermis, collagens XVI and XII, oxytalan fibres     

Morphological investigation of chemical peel on photodamaged facial skin

Chemical peeling involves the topical application of a wounding agent with the goal of effecting an organized regeneration of the skin. The histological and ultrastructural features of actinic- and age-related damage include structural abnormalities that disrupt normal epidermal and dermal architecture. In the present study, five patients with actinically damaged skin underwent an enhanced medium depth peel using 70% glycolic acid and 35% trichloroacetic acid. Biopsy specimens were taken before the peel, and 3 months after the peel for histological and electron microscopic examination. Clinical resolution of actinic damage corresponded with restoration of epidermal polarity. Characteristic histological and ultrastructural features of the skin after peeling include markedly decreased epidermal intracytoplasmic vacuoles, decreased elastic fibres, increased activated fibroblasts and organized parallel arrays of collagen fibrils. We conclude that electron microscopic studies after a medium depth peel of photodamaged skin reveal more profound changes than those seen histologically.     

4 种食源性肽改善SD大鼠光老化皮肤弹性及机理的比较分析

为评价4 种食源性肽口服后对SD大鼠光老化皮肤弹性的改善效果并探讨其力学机制,将健康成年雌性SD 大鼠随机分为空白对照组、紫外线（ultraviolet,UV）辐照模型组、4 种活性肽摄取组,空白组不施行UV辐照,模 型组及肽组均行UVA＋UVB联合辐照,4 种活性肽分别配制成0.3、0.9、1.5 g/L的含肽水溶液口服,脱毛后连续UV 辐照18 周至光老化模型建立,测定皮肤弹性后将动物处死,取其背部皮肤制备匀浆,生化法测定羟脯氨酸和透明 质酸含量,酶联免疫吸附法检测Ⅰ型胶原蛋白（collagen I,Col I）、III型胶原蛋白（Col III）含量及基质金属蛋白 酶-1（matrix metalloproteinase-1,MMP-1）活力,另取部分皮肤组织进行石蜡包埋、切片后进行苏木精-伊红染色 观察。结果表明,与空白组相比,模型组大鼠皮肤弹性,Col I、羟脯氨酸、透明质酸含量显著降低（P＜0.05）, 而Col III含量及MMP-1活力显著升高（P＜0.05）,组织化学显示皮肤表皮增生,真皮层胶原纤维排列紊乱、且断 裂呈片段化聚集扭曲,基底膜溶解呈扁平化。与模型组相比,4 种活性肽口服后均能改善皮肤弹性,且样品2效果 最显著,其皮肤组织中Col I、羟脯氨酸、透明质酸含量显著升高（P＜0.05）,而Col III含量及MMP-1活力显著降 低（P＜0.05）。组织化学显示样品2摄食组大鼠表皮增生明显改善,真皮层增厚、胶原纤维增加,排列趋向均匀化 致密分布,不同程度上恢复到空白组波浪状规律排列,提示样品2提高光老化SD大鼠皮肤弹性的机理在于促进了胞 外基质（extracellular matrix,ECM）的生物合成,抑制了ECM降解酶MMP-1活力,修复了受损皮肤的力学结构。     

Cosmetic efficacy claims in vitro using a three-dimensional human skin model

A tissue engineered human skin equivalent is successfully used for the testing of raw materials and cosmetic formulations. This reconstructed skin is supported by a collagen-glycosaminoglycan-chitosan biopolymer in which human keratinocytes and dermal fibroblasts were co-cultured to form a tissue that closely reproduces the in vivo architecture of normal human skin and takes into account the complex interactions between epidermis and dermis. On the other hand, dermal and epidermal responses can be assessed separately in the dermal or skin equivalent. The three-dimensional model has important advantages compared to monolayer cell cultures and epidermis models in efficacy testing: (i) the possibility of long-term cultivation with repeated application of cream formulations containing bioactives and (ii) the similarity to human skin concerning the interaction between dermis and epidermis. These similarities include the expression of keratinocyte differentiation markers such as cytokeratin 10, filaggrin and transglutaminase, as well as proteins of the basal lamina (laminin, collagen type IV) and extracellular matrix proteins such as elastin. The efficacy of selected bioactives was determined using different endpoints, for example, stimulation of collagen synthesis in the dermal and skin equivalents was shown in comparison to vitamin C as a positive control. On skin equivalents using immunofluorescence techniques we also demonstrated stimulation of the differentiation marker filaggrin, which is important for skin moisturization. The results could be used for claim substantiation, e.g. for the treatment of dry and aged skin.     

Modelling and simulation of 3D orthogonal fabrics for composite applications

The present paper focuses on geometric and micromechanical modelling of 3D orthogonal fabrics for composite applications and employs meso-finite element (FE) modelling for it. FE modelling of textile composites is a powerful tool for the homogenisation of mechanical properties, study of stress–strain fields inside the unit cell, determination of damage initiation conditions and sites and simulation of damage development and associated deterioration of the homogenised mechanical properties of the composite. Meso-FE can be considered as a part of the micro-meso–macro-multi-level modelling process, with micromodels (fibres in the matrix) providing material properties for homogenised impregnated yarns and fibrous plies, and macromodel (structural analysis) using results of meso-homogenisation.     

Skin benefits of a myconoside-rich extract from resurrection plant Haberlea rhodopensis

Resurrection plant Haberlea rhodopensis develops molecules to survive drought stress. These molecules allow the plant to resurge from a desiccation state. We have extracted a specific fraction from the plant (Haberlea extract) and found it rich, among other molecules, of a caffeoyl phenylethanoid glycoside called myconoside, a molecule extremely abundant in the plant with a potential role in survival. Peroxide‐stressed normal human dermal fibroblasts treated with the Haberlea extract, showed increased collagen VI (+822%), collagen XVI (+928%) and elastin (+144%) mRNA synthesis, measured by RT‐qPCR. This effect was superior to those obtained with benchmarks retinoic acid and retinol. When used at 3% in human skin biopsies, Haberlea extract protected against UV‐induced dermis oxidation by 100% (P < 0.01), as evidenced by immunohistochemistry. Finally, when tested in human volunteers (n = 20) at 3% in a cream against a placebo, Haberlea extract increased skin elasticity (3× placebo, P < 0.0002) and skin radiance (4× placebo, P < 0.05) after only 15 days of treatment, with the effect sustained after 30 and 60 days of treatment. We demonstrated that by using Haberlea extract (particularly rich in glycoside myconoside), it is possible to strongly stimulate antioxidant skin defences and extracellular matrix protein synthesis. This effect, in turn, will further stimulate skin elasticity and skin radiance significantly in human volunteers. The extract can be suggested for anti‐ageing treatments, intended for claims such as protection from oxidation, increased skin elasticity and enhanced skin radiance.