Effects Of Photoaging Research Articles

Coffee Extract as an Antioxidant in the Prevention of Photoaging: Literature Review

Photoageing leads to dry skin, wrinkles, darkening of skin pigmentation and a reduction in skin firmness. The effects of photoaging may be overcome by compounds which have antioxidant activity. Coffee is a potential candidate for synthetic chemicals in cosmetic preparations. It contains active compounds, including polyphenols, caffeine, chlorogenic acid, flavonoids, and alkaloids which are effective for use on the skin as antioxidants, anti-aging, sunscreens, moisturizers, anti-cellulite, and brighteners. That makes coffee a potential antioxidant in the treatment of photoageing. The purpose of this literature review is to determine whether coffee extract is an anti-oxidant in the treatment of photoaging. A comprehensive literature search was conducted using several databases, namely Google Scholar, PubMed, Scopus, and Crossref, using the keywords “coffee AND antioxidant AND photoaging.” This literature review concluded that coffee extract could be used as an antioxidant in treating photoaging. Keywords: Coffee, Antioxidant, Photoaging

Flavonoid components and anti-photoaging activity of flower extracts from six Paeonia cultivars

Genus Paeonia is an important ornamental and medicinal crop. The flowers of Paeonia are rich in flavonoids, and flavonoids have excellent antioxidant and anti-inflammatory activities, which have the potential to slow down skin aging. In this study, flavonoids from whole flowers of six popular Paeonia cultivars were extracted using three different solvents. The composition and content of peony flowers flavonoids extracted with three solvents were determined by high performance liquid chromatography quadrupole time-of-flight mass spectrometry / mass spectrometry (HPLC-Q-TOF-MS/MS) and HPLC-diode array detection (DAD). A total of 26 flavonoids were isolated and identified, and 60 % ethanol showed the highest extraction efficiency. Not only flavonoids composition but also the content was significantly different in different peony flowers, among which ‘Hei Tian E’ had the most abundant composition (17 flavonoids) and the highest total content of flavonoids (57.75 mg/g DW by using 60 % ethanol). After that, the anti-skin photoaging effects of the 60 % ethanol extracts of the six Paeonia cultivars flowers were evaluated by UVR-Fulkutis and UVA-Fibroblasts photoaging models. Under exposure to UV radiation, some Paeonia flowers’ extracts can prevent the decrease of skin surface thickness and reduce the loss of Collagen IV and VII. In addition, the production and accumulation of ROS, MMP-1 and MMP-3 in fibroblasts were inhibited, indicating the attenuation of skin photoaging by the extracts. Among the six samples tested, ‘Hei Tian E’ whole flower extract (BH-HT) had the best comprehensive effect. Finally, the correlations between components and anti-photoaging efficacy were analyzed. We speculate that the anti-photoaging effect was significantly related to its richness in quercetin 3-O-di-glucoside, quercetin 3-O-glucoside, isorhamnetin 3-O-galloyl arabinoside, cyanidin 3,5-di-O-glucoside, cyanidin 3-O-glucoside, and peonidin 3-O-glucoside. In general, the results show that Paeonia flowers have potential for development of anti-photoaging herbal essence products.

CO2 ablative fractional laser - mechanism of action and assessment of safety, effectiveness in the treatment and possible side effects based on a review of scientific literature

Introduction: Laser therapy has been used in medicine for many years. One of the most willingly used is the fractional ablative CO2 laser. As a result of its use, the improvement of pigmentation, skin texture and signs of aging are achieved. Laser therapy owes its popularity to its low invasiveness and good, long-lasting effects of the procedure. Despite its important role in aesthetic medicine, we should not forget about its participation in the treatment of scars, often extensive, causing troublesome symptoms to patients, the source of which is not only a defect of a cosmetic nature. Purpose of the work: The purpose of the study is to present mechanism of action, assessment of safety, effectiveness in the treatment and possible side effects based on a review of scientific literature. Material and methods: The work was based on a review of available medical publications on the use of the fractional ablative CO2 laser. The literature in the PubMed and Google Scholar databases was searched based on the following keywords: fractional ablative CO2 laser, mechanism of action, safety of use, side effects. Conclusion: The use of a fractional ablative CO2 laser causes the increased collagen production in the dermis. This effect contributes to the elevation of the quantity and level of collagen arrangement, and also to the reduction of the visibility of the effects of photoaging. As a result, the skin in the treated area becomes thicker, and thus firmer. The pigmentation and texture are also being improved. The procedure is relatively slightly invasive, and the side effects are self-limiting in the most cases.

Anti-photoaging Effect of Micronized Fat in Ultraviolet B-Induced Human Dermal Fibroblasts.

Adipose-derived stromal vascular fraction and mesenchymal stem cells have been proven to reduce the effects of skin photoaging. However, there is no standardized protocol for their preparation. This study aimed to investigate the skin rejuvenation potential of micronized fat, obtained using a novel device attached with a trifoliate blade, in the ultraviolet B-induced human dermal fibroblasts model. Micronized fat was prepared to obtain adipose-derived stromal vascular fraction and the adipose-derived mesenchymal stem cells to stromal vascular fraction ratio was determined by flow cytometry. The ultraviolet B-induced human dermal fibroblasts model was constructed to identify the characteristic of the human dermal fibroblasts using Vamiten and S-100 immunostaining, observe their morphology, and measure the levels of photoaging related factors. After the previous steps were completed, different cell groups were co-cultured with ultraviolet B-induced human dermal fibroblasts and the extent of improvement of photoaging was evaluated. Micronized fat had a higher adipose-derived mesenchymal stem cells to stromal vascular fraction ratio than the control fat preparations. The ultraviolet B-induced human dermal fibroblasts model showed lowered levels of type I collagen and transforming growth factor-βand increased expression of matrix metalloproteinases, which are the characteristics of photoaging in normal human dermal fibroblasts. Compared to different cell groups co-cultured with ultraviolet B-induced human dermal fibroblasts, micronized fat could lower the expression of matrix metalloproteinases and increase the level of type I collagen but lower the level of transforming growth factor-β. Obtaining micronized fat is more effortless and clinically safer. Micronized fat has an anti-photoaging effect by inhibiting the expression of MMPs via MAPK signaling pathway.

Purification and Identification of Peptides from Oyster (Crassostrea hongkongensis) Protein Enzymatic Hydrolysates and Their Anti-Skin Photoaging Effects on UVB-Irradiated HaCaT Cells.

This study aimed to purify and identify antiphotoaging peptides from oyster (Crassostrea hongkongensis) protein enzymatic hydrolysates (OPEH) and to investigate the possible mechanism underlying its antiphotoaging effect. Multiple methods (Ultrafiltration, G25 Chromatography, RP-HPLC, and LC/MS/MS) had been used for this purpose, and eventually, two peptides, including WNLNP and RKNEVLGK, were identified. Particularly, WNLNP exerted remarkable antiphotoaging effect on the UVB-irradiated HaCaT photoaged cell model in a dose-dependent manner. WNLNP exerted its protective effect mainly through inhibiting ROS production, decreasing MMP-1 expression, but increasing extracellular pro-collagen I content. Furthermore, WNLNP downregulated p38, JNK, ERK, and p65 phosphorylation in the MAPK/NF-κB signaling pathway and attenuated bax over-expressions but reversed bcl-2 reduction in UVB- irradiated HaCaT cells. The molecular docking analysis showed that WNLNP forms five and seven hydrogen bonds with NF-κB (p65) and MMP-1, respectively. This study suggested that a pentapeptide WNLNP isolated from OPEH had great potential to prevent and regulate skin photoaging.

Combined effects of photoaging and natural organic matter on the colloidal stability of nanoplastics in aquatic environments

The transport and fate of nanoplastics (NPs) in aquatic environments are closely associated with their colloidal stability, which is affected by aging and natural organic matter (NOM) adsorption. This study systematically investigated the combined effects of photoaging and NOM (e.g. humic acids, HA; and a model protein, bovine serum albumin, BSA) on the aggregation kinetics of NPs (polystyrene, PS) in NaCl and CaCl2 solutions. Our results showed that photoaged NPs adsorbed less HA than pristine NPs due to weaker hydrophobic and π-π interactions. In return, HA showed weaker impacts on NPs’ stability after photoaging. Differently, photoaged NPs absorbed more BSA than pristine NPs due to stronger hydrogen bonding and electrostatic attraction. Thus, the inhibitory effects of BSA on the aggregation kinetics of NPs were enhanced after photoaging. Regarding the effects of NOM on the aging of NPs, our results showed that HA competed with NPs for photons and underwent photo-degradation. Subsequently, the destruction/reconstruction of adsorbed HA increased (in NaCl) or decreased (in CaCl2) the stability of NPs. Notably, light radiation-induced flocculation of BSA molecules, which wrapped and integrated NPs and lead to their destabilization. Overall, this study provided new insights into the aggregation behavior of NPs in aquatic systems, which have significant implications for predicting the transport and fate of NPs in complex real-world environments.

Dendrobium nobile Lindl. Polysaccharides protect fibroblasts against UVA-induced photoaging via JNK/c-Jun/MMPs pathway

Ethnopharmacological relevanceDendrobium nobile Lindl. is an orchid species that is found throughout Asia, including Thailand, Laos, Vietnam, and China. It has been used to treat tumors, hyperglycemia, hyperlipidemia, and neurological disorders caused by aging in recent decades. Aim of the studyTo investigate the antagonistic effect of Dendrobium nobile Lindl. Polysaccharides (DNLP) on UVA-induced photoaging of Human foreskin fibroblasts (HFF-1) and explore its possible anti-aging mechanisms. Materials and methodsAn in vitro photoaging model of dermal fibroblasts was established with multiple UVA irradiations. Fibroblasts were treated with 0.06 mg/ml, 0.18 mg/ml, 0.54 mg/ml of DNLP one day before photodamage induction. The levels of reactive oxygen species (ROS), Malondialdehyde (MDA), cell viability and longevity, Superoxide Dismutase (SOD), Catalase (CAT), and Glutathione peroxidase (GSH-Px) enzymatic activities were determined. We examined how DNLP ameliorates the effects of photoaging, the JNK/c-Fos/c-Jun pathway, senescence-associated β-galactosidase (SA-β-Gal), and MMP expression levels were measured. ResultsUVA irradiation reduced the viability, lifespan, and proliferation of HFF-1 cells, increased ROS and lipid peroxidation and decreased the activities of free radical scavenging enzyme systems SOD, CAT, and GSH-Px. DNLP treatment can reverse UVA damage, reduce SA-β-Gal expression, reduce phosphorylation activation of the JNK/c-Fos/c-Jun pathway and inhibit MMP-1, MMP-2 MMP-3, and MMP-9 protein expression. ConclusionsDNLP can effectively inhibit UVA damage to HFF-1 and prevent cell senescence. Its mechanism of action may increase antioxidant enzyme activity while inhibiting JNK pathway activation and MMPs expression.

The impact of particle size and photoaging on the leaching of phthalates from plastic waste

Plastic wastes are important sources of phthalates (PAEs), which are a class of endocrine disrupting compounds (EDCs). However, there are still knowledge gap about how environmental weathering processes affect the release of PAEs from plastics wastes. In this study, we investigated the effects of particle size and photoaging on the leaching of PAEs from two kinds of commercial polyethylene plastic express packaging bags with different PAEs contents. Reduction of the size of the plastic from 5 cm to <0.5 mm did not significantly change the leaching of PAEs from the express packaging bags. After photoaging, the sum of all detected PAEs (∑PAEs) leaching amounts from two plastic bags were 1.76–2.91 times and 1.24–2.19 times higher than those of the two original materials, respectively. However, due to the degradation effect of ultraviolet (UV) irradiation on PAEs in plastics, the leaching amount of PAEs decreased at the later stage of the photoaging. The effect of photoaging on the surface properties of polyethylene (PE) plastics, especially on the surface functional groups and hydrophilicity, contributed significantly to the leaching of PAEs. The result of this study indicated that the risk of PAEs release from plastic wastes in the environment could be promoted by photoaging processes. Considering the high leaching ratios of PAEs from plastic packaging materials in this study, these plastic bags may increase the environmental burden and risk of PAEs, even though the PAEs levels of them are low.

Anti-photoaging effects and mechanisms of active ingredients of Chinese medicine: a review

Skin photoaging is exogenous aging caused by long-term ultraviolet radiation, which not only affects skin appearance, but also has a close relationship with the development of skin cancer. Saponins, flavonoids, polyphenols, polysaccharides, and extracts of Chinese medicine have been found to have anti-skin photoaging effects in recent studies. Various mechanisms such as anti-oxidative stress damage, inhibition of matrix metalloproteinase expression, promotion of collagen synthesis, inhibition of inflammatory response, DNA damage repair, enhancement of cell autophagy, and inhibition of melanin synthesis can improve the symptoms of skin photoaging and delay the photoaging process. With the active ingredients of Chinese medicine for anti-skin photoaging as the entry point, the study systematically discussed the research progress of the mechanisms underlying the anti-photoaging effects of active ingredients of Chinese medicine in recent years, in order to provide theoretical reference for the development of new anti-photoaging drugs and methods.

Anti-photoaging effects of flexible nanoliposomes encapsulated Moringa oleifera Lam. isothiocyanate in UVB-induced cell damage in HaCaT cells

Skin photoaging is premature skin aging damage that occurs after repeated exposure to ultraviolet (UV) radiation. Although isothiocyanates extracted from the moringa tree (Moringa oleifera Lam.) (MITC) exhibit excellent effects against skin photoaging, its application is restricted because of its characteristics, such as extremely low water solubility, bioavailability, and easy degradation. Currently, flexible nanoliposomes have gained increasing interest as a biocompatible polymer for applications such as transdermal drug delivery. We prepare amphiphilic hyaluronic acid (HA) conjugated with ceramide (CE) to modify nanoliposomes for MITC (HACE/MITC NPs) delivery. The HACE/MITC nanoparticles (NPs) are prepared and characterized for entrapment efficiency, particle size, polydispersity index, zeta potential, in vitro release, in vivo skin permeation, and in vitro protective effect of photoaging. The zeta potential of MITC NPs and HACE/MITC NPs is −24.46 mV and −24.93 mV, respectively. After modification of HACE, the entrapment efficient of MITC liposome increased from 62.54% to 70.67%, and the particle size decreased from 266.1 nm to 192.8 nm. In vivo skin permeation, permeated drug increased from 49.42 to 71.40%. Moreover, the results showed that the entrapment of MITC in nanoliposomes improves its stability, efficacy, and skin permeation. Further, HACE/MITC NPs are favorable for uptake by HaCaT cells without requiring changes in cell morphology, which significantly improves the activities of antioxidant enzymes, scavenges UVB-induced reactive oxygen species, protects skin from damage, and reduces MMP-1, MMP-3, and MMP-9 expression caused by radiation-induced photoaging. Our results strongly suggest that flexible nanoliposomes successfully improved the cell membrane permeation of MITC, and that anti-photoaging and HACE/MITC NPs can potentially be used as candidates for photoaging therapy.

New insights on metal ions accelerating the aging behavior of polystyrene microplastics: Effects of different excess reactive oxygen species

Microplastics (MPs) will coexist with various pollutants in the environment, but it is not clear whether these pollutants will affect the aging process of MPs. The aging process of polystyrene microplastics (PS-MPs) mediated by Cu2+ and Pb2+ was investigated in this study. The results showed that the aging rate of PS-MPs mediated by Cu2+ and Pb2+ were significantly higher than that of ultrapure water (After 7 days of light irradiation, the CI values of aging PS-MPs mediated by ultrapure water, Cu2+ and Pb2+ increased from 0.030 of original PS-MPs to 0.034, 0.048 and 0.086 respectively). This process may be related to the generation of a large amount of reactive oxygen species, because OH were detected in PS-MPs suspension mediated by Cu2+, which were significantly higher than those in ultrapure water, while 1O2 mediated by Pb2+ were more. However, these photo-aging effects were significantly inhibited by reactive oxygen species (ROS) quencher, which indicated that excessive ROS production was the main reason for metal ions to promote the photo-aging of PS-MPs. In addition, this study reported that excessive ROS will accelerate the formation of carbonyl group on the surface of PS-MPs, and lead to the change of physical and chemical properties of PS-MPs. This study provides new insights for the environmental behavior of MPs under the condition of combined pollution.

Systematic Literature Review: Efektivitas Ekstrak Kopi sebagai Antioksidan dalam Mengatasi Photoaging

Aging of the skin due to exposure of UV rays is referred as photoaging. Photoaging causes dry skin, wrinkles, darker skin pigmentation, and reduced skin firmness. The effect of photoaging can be treated by compounds that have antioxidant activity. Coffee contains polyphenols (caffeic acid and chlorogenic acid) which can inhibit the formation of ROS free radicals. This makes coffee an antioxidant potential in photoaging treatment. This study aims to determine the effectiveness of coffee extract as an antioxidant in photoaging treatment. The method used in this study is Systematic Literature Review. A comprehensive literature search was conducted using the Harzing's Publish or Perish application on several databases, such as Google Scholar, PubMed, Scopus, and Crossref using the keywords "coffee AND antioxidant AND ultraviolet AND photoaging". The article selection flow used the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) protocol. The total search results were 1202 articles, and there were 6 research articles that matched the inclusion and exclusion criteria that had been set. The results of this study concluded that coffee extract can be used as an antioxidant in photoaging treatment. The effectiveness of coffee extract as an antioxidant in photoaging treatment was demonstrated by reducing the expression of MMPs, increasing the expression of type 1 procollage, reducing the area of wrinkles, and reducing TEWL. Coffee leaf extract decreased the expression of MMPs (MMP-1 ¯ 50%, MMP-3 ¯ 10% to 60%, MMP-9 ¯ 30% to 50%) and increased type 1 procollagen 60%. Coffee bean extract decreased the expression of MMPs (MMP-1 ¯ 5% to 60%, MMP-2 ¯ 20% to 60%, MMP-3 ¯ 30%, MMP-9 ¯ 20% to 70%, MMP-13 ¯ 30% to 45%), increased type 1 procollagen 10% to 60%, reduced wrinkle area 20% to 88%, and decreased TEWL 10% to 20%.

The dark side of daylight: photoaging and the tumor microenvironment in melanoma progression.

Continued thinning of the atmospheric ozone, which protects the earth from damaging ultraviolet radiation (UVR), will result in elevated levels of UVR reaching the earth's surface, leading to a drastic increase in the incidence of skin cancer. In addition to promoting carcinogenesis in skin cells, UVR is a potent extrinsic driver of age-related changes in the skin known as "photoaging." We are in the preliminary stages of understanding of the role of intrinsic aging in melanoma, and the tumor-permissive effects of photoaging on the skin microenvironment remain largely unexplored. In this Review, we provide an overview of the impact of UVR on the skin microenvironment, addressing changes that converge or diverge with those observed in intrinsic aging. Intrinsic and extrinsic aging promote phenotypic changes to skin cell populations that alter fundamental processes such as melanogenesis, extracellular matrix deposition, inflammation, and immune response. Given the relevance of these processes in cancer, we discuss how photoaging might render the skin microenvironment permissive to melanoma progression.

Effect of Aging Conditions and Rubber Waste Content on the Mechanical Properties and Structure of Montmorillonite/Acrylonitrile Butadiene Rubber Nanocomposites

The research described in the present work investigated the effect of thermal and photoaging and rubber waste content on the properties of acrylonitrile–butadiene rubber modified with montmorillonite (MMT). The MMT was mixed with plasticizer before the compounding in two roll mills. The modulus at 300% strain of samples without scrap maximally increased by 50% and 30% after thermal and photoaging, respectively, most probably due to an increase in the crosslink density. The maximum increases of the modulus, measured at 300% strain, of the unaged and aged rubber nanocomposite were exhibited by samples which each contained 10 wt.% of rubber waste. The MMT nanoparticles, well dispersed in the matrix, combined with good interfacial interaction between the different components, led to relative retention of the thermal and photo-oxidation aging coefficients and the large shape retention coefficient of the tested samples. Fourier transform infrared spectra showed that the crosslinking of the rubber nanocomposites containing waste occurred through the nitrile groups and C = C double bonds under the influence of aging. Scanning electron microscopy micrographs indicated that the MMT nanoparticles were uniformly embedded and well dispersed in the matrix. The rough and homogeneous fracture surfaces of the nanocomposite samples were not affected by incorporated waste. As a result of UV irradiation and thermal heating, aggregates were less visible and the fracture surfaces more homogeneous and compact.

Release of Zinc and Polycyclic Aromatic Hydrocarbons From Tire Crumb Rubber and Toxicity of Leachate to Daphnia magna: Effects of Tire Source and Photoaging.

Tire crumb rubber (TCR) has been widely used in artificial turf fields, however, the potential environmental risk of TCR and the effect of sunlight exposure are scarcely studied. Here, we evaluated leachability of Zn and polycyclic aromatic hydrocarbons (PAHs) in four types of TCRs and acute toxicity of leachates to Daphnia magna. The results showed that all types of TCRs tested released Zn (0.20-1.3μg/g) and PAHs (9.4-17μg/g) but only two were lethal to D. magna (mortality 73%). Notably, ultraviolet (UV) irradiation induced TCR to generate acidic leachate (pH ~ 4.8), which contained 24- and 1.2-fold higher concentrations of Zn and PAHs and therefore was more toxic to D. magna than that in the absence of UV treatment. These findings demonstrate source-dependent toxicity of TCR and highlight the need to consider the effect of photoaging when evaluating the environmental risks of TCR.

Changes in Skin Elasticity and Firmness Caused by Cosmetic Formulas Elaborated with Essential Oils of Aristeguietia glutinosa (matico) and Ocotea quixos (ishpingo). A Statistical Analysis

External factors such as prolonged exposure to solar radiation and environmental pollution accelerate the aging process of the skin, and this process is a challenge for pharmacological science. To counteract the effects of skin photoaging, the cosmetic industry has introduced natural topical products that have proved to be effective in reducing signs of age. In this sense, a statistical analysis was conducted on the changes in the properties of firmness and elasticity of the skin caused by cosmetic formulas (lotion and cream) elaborated with essential oils of Aristeguietia glutinosa (matico) and Ocotea quixos (ishpingo) in which the concentration of the oils in two cosmetic products (lotion and cream) varied to be tested in vivo, through the measurement of elasticity and firmness in three times T1 (0 day), T2 (28 days) and T3 (56 days), and in two age groups according to the Glogau scale (30 to 40 and 41 to 50 years). The results showed positive changes in the values of elasticity and firmness of the skin in the presentation of the lotion whose concentration was 20% Aristeguietia glutinosa (matico) and 80% Ocotea quixos (ishpingo), with a minimum application time of 28 days.

The Anti-photoaging Effects of Pre- and Post-treatment of Platelet-rich Plasma on UVB-damaged HaCaT Keratinocytes.

To investigate the anti-photoaging effects of pre- and post-treatment of PRP on UVB-damaged HaCaT cells. HaCaT cells were irradiated with 80mJ/cm2 UVB, before or after PRP treatment (1000×107 /L), and following measurements were taken: survival rate of UVB-irradiated HaCaT cells, malondialdehyde (MDA) content and activities of glutathione peroxidase (GSH-Px), superoxide dismutase (SOD) and catalase (CAT). Western blot was used to determine the effect of different PRP intervention on the expression of PI3K, AKT, ERK, MMP-1, MMP-9, TIMP-1 and γ-H2AX in the UVB-irradiated HaCaT cells. pre- and post-PRP treatment reduced MDA content and increased the activities of GSH-Px, SOD and CAT in photoaged HaCaT cells. These changes resulted in reduced cytotoxic effects. Besides, different PRP intervention promoted cell proliferation via PI3K/AKT pathway. Furthermore, PRP application suppressed the expression of γ-H2AX. Also, PRP intervention alleviated photoaging effects by upregulating the expression level of tissue inhibitor of metalloproteinases-1 (TIMP-1) while downregulating matrix metalloproteinase (MMP) expression level in photoaged HaCaT cells. pre- and post-PRP treatment play anti-photoaging role through strengthening cellular oxidative defense capacity, mitigating MMP expression, alleviating DNA damages and promoting proliferation of UVB-irradiated HaCaT cells.

Protocatechuic Aldehyde Attenuates UVA-Induced Photoaging in Human Dermal Fibroblast Cells by Suppressing MAPKs/AP-1 and NF-κB Signaling Pathways.

Ultraviolet radiation (UV) is a major causative factor of DNA damage, inflammatory responses, reactive oxygen species (ROS) generation and a turnover of various cutaneous lesions resulting in skin photoaging. The purpose of this study is to investigate the protective effect of protocatechuic aldehyde (PA), which is a nature-derived compound, against UVA-induced photoaging by using human dermal fibroblast (HDF) cells. In this study, our results indicated that PA significantly reduced the levels of intracellular ROS, nitric oxide (NO), and prostaglandins-E2 (PGE2) in UVA-irradiated HDF cells. It also inhibited the levels of cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS) expression. Besides, PA significantly suppressed the expression of matrix metalloproteinases-1 (MMP-1) and pro-inflammatory cytokines and promoted collagen synthesis in the UVA-irradiated HDF cells. These events occurred through the regulation of activator protein 1 (AP-1), nuclear factor-κB (NF-κB), and p38 signaling pathways in UVA-irradiated HDF cells. Our findings suggest that PA enhances the protective effect of UVA-irradiated photoaging, which is associated with ROS scavenging, anti-wrinkle, and anti-inflammatory activities. Therefore, PA can be a potential candidate for the provision of a protective effect against UVA-stimulated photoaging in the pharmaceutical and cosmeceutical industries.

The influence of retinol concentration in liquid crystal formula on epidermal growth factor, interleukin-6 and transglutaminase-1 mRNA expression in the epidermis.

Topical retinol application effectively reduces the effects of photoaging and improves skin condition, e.g. influences the process of keratinization of the epidermis, which improves stratum corneum structure and reduces transepidermal water loss. However, cosmetics use lower concentrations of retinol, which has been associated with emerging hypersensitivity reactions as well as redness and irritation of the skin. The question arises whether the vehicle used in the cosmetic may be important in stimulating the inflammatory reaction in the skin and if the concentration of retinol used could significantly affects the growth of epidermal cells. The aim of this study was to evaluate the effects of different concentrations of liquid crystal retinol (0.15%, 0.3% and 0.5%) on the clinical and histological characteristics of a reconstructed epidermis skin model. It also compares the effectiveness of 0.3% retinol formula in liquid crystal to that in lipid. The study used reconstructed human epidermis tissue containing normal human keratinocytes. Four original formulas containing retinol were tested: 0.15%, 0.3% and 0.5% with a liquid crystal base, and 0.3% with a lipid base. Interleukin 6 (IL-6), transglutaminase-1 (TGM1), and epidermal growth factor (EGF) mRNA expression was measured expression of the skin-equivalent tissue for 10 days of exposure. Histopathological analysis and mRNA quantification were performed. Gene expression was analyzed by total mRNA extraction. All liquid crystal formulas induced higher EGF mRNA expression than lipid base formula. IL-6 expression did not differ significantly from the DPBS reference values. Interestingly, TGM1 expression was found to increase together with increasing retinol concentration (0.15%, 0.3%, 0.5%). Histological examination revealed changes in epidermal structure, mainly hyperkeratinization of the stratum corneum. Our results support the hypothesis liquid crystal formula might be regarded as more beneficial since it inducess less pro-inflammatory action manifested by lowered expression IL-6. In addition, EGF expression was found to correlate significantly with the retinol concentration of the liquid crystal formula: 0.5% > 0.3% > 0.15% (P < 0.05). Lower concentrations may increase TGM1 expression, thus enhancing the formation of a protective layer of cornified envelope.

Understanding the role of p38 and JNK mediated MAPK pathway in response to UV-A induced photoaging in Caenorhabditis elegans

Premature aging of the skin, principally induced by the UV radiations is called as photoaging, characterized by an increase in the level of ROS and the damage of the collagen layer leading to the damage of the cells. Mitogen activated Protein kinase (MAPK) pathway is known to mediate photoaging by controlling the level of ROS and initiating detoxification. Caenorhabditis elegans, a known model to analyze photoaging was used to understand the role of MAPK pathway (p38 and JNK) during UV-A mediated photoaging. Gene specific mutants of p38 MAPK pathway showed reduced survival when exposed to UV-A suggesting that UV-A mediated photoaging was dependent on this pathway. Also, the role of SKN-1 in eliciting response against UV-A was analyzed with the help of GFP tagged strains and qPCR analysis. Further, UV-A did not have any impact on the lifespan of JNK pathway mutants suggesting the importance of the pathway in eliciting a response against UV-A exposure, which was further validated by Western blot analysis. Overall, this study suggests that MAPK pathway could play an important part in initiating and eliciting a response by the host against UV-A exposure, by which it could be used as a marker to analyze the effects of photoaging.