UV-induced Changes Research Articles

The Effect of Cannabidiol on UV-Induced Changes in Intracellular Signaling of 3D-Cultured Skin Keratinocytes.

Human epidermal keratinocytes are constantly exposed to UV radiation. As a result, there is a significant need for safe and effective compounds to protect skin cells against this environmental damage. This study aimed to analyze the effect of phytocannabinoid-cannabinoid (CBD)-on the proteome of UVA/B irradiated keratinocytes. The keratinocytes were cultured in a three-dimensional (3D) system, designed to mimic epidermal conditions closely. The obtained results indicate that CBD protected against the harmful effects of UVA/B radiation. CBD decreased the expression of proinflammatory proteins, including TNFα/NFκB and IκBKB complex and decreased the expression of proteins involved in de novo protein biosynthesis, which are increased in UVA/B-irradiated cells. Additionally, CBD enhanced the UV-induced expression of 20S proteasome subunits. CBD also protected protein structures from 4-hydroxynonenal (HNE)-binding induced by UV radiation, which primarily affects antioxidant enzymes. CBD-through its antioxidant/anti-inflammatory activity and regulation of protein biosynthesis and degradation-protects skin cells against UVA/B-induced changes. In the future, its long-term use in epidermal cells should be investigated.

Phosphoproteomic Analysis Reveals Rio1-Related Protein Phosphorylation Changes in Response to UV Irradiation in Sulfolobus islandicus REY15A

DNA damage response (DDR) in eukaryotes is largely regulated by protein phosphorylation. In archaea, many proteins are phosphorylated, however, it is unclear how the cells respond to DNA damage through global protein phosphorylation. We previously found that Δrio1, a Rio1 kinase homolog deletion strain of Sulfolobus islandicus REY15A, was sensitive to UV irradiation. In this study, we showed that Δrio1 grew faster than the wild type. Quantitative phosphoproteomic analysis of the wild type and Δrio1, untreated and irradiated with UV irradiation, revealed 562 phosphorylated sites (with a Ser/Thr/Tyr ratio of 65.3%/23.8%/10.9%) of 333 proteins in total. The phosphorylation levels of 35 sites of 30 proteins changed with >1.3-fold in the wild type strain upon UV irradiation. Interestingly, more than half of the UV-induced changes in the wild type did not occur in the Δrio1 strain, which were mainly associated with proteins synthesis and turnover. In addition, a protein kinase and several transcriptional regulators were differentially phosphorylated after UV treatment, and some of the changes were dependent on Rio1. Finally, many proteins involved in various cellular metabolisms exhibited Riol-related and UV-independent phosphorylation changes. Our results suggest that Rio1 is involved in the regulation of protein recycling and signal transduction in response to UV irradiation, and plays regulatory roles in multiple cellular processes in S. islandicus.

Predicting miRNA-lncRNA-mRNA network in ultraviolet A-induced human skin photoaging.

Recent researches had reported that microRNAs (miRNAs) played a role in skin photoaging. Our previous study found that long noncoding RNA (lncRNA) expression was changed in the UVA-irradiated skin fibroblasts, but the regulating network of noncoding RNA in UV-induced skin changes has not been elucidated well. Here, we investigated the interactions of miRNA-lncRNA-mRNAs in skin photoaging mechanisms. Human dermal fibroblasts (HDFs) were irradiated with UVA at 10J/cm2 once a day lasting for 14days. miRNA expression profiles were detected by high-throughput sequencing. miRNAs changed significantly were identified by qRT-PCR. Functional annotation analysis and pathway enrichment were carried out using Gene Ontology and KEGG, and predicted miRNA-lncRNA-mRNA interactions were performed via bioinformatic analysis. 34 differentially expressed miRNAs (>1.5-fold changes, P<.05) after UVA irradiation were identified to interact with distinct lncRNAs. miRNA-lncRNA-mRNA network prediction and regulatory role analysis showed that the gene expression of cellular process, cell part, and binding was mainly coordinated in UVA-irradiated fibroblasts. miRNA-lncRNA-mRNA-signal transduction pathway analysis showed that TNF signaling pathway, thyroid hormone signaling pathway, and lysosome were mainly affected after UVA irradiation. miRNA-lncRNA-mRNA network played a critical part in skin photoaging. Our research provided novel insights into the repeated UVA-induced skin damage in noncoding RNA regulatory field and might help to further understand the delicate interplay of gene regulation at the noncoding RNA level in photoaged skin and UV-induced skin cancers in future researching and provide novel insights into the repeated UVA-damaging pathology and potential targets for preventing human skin photoaging.

Therapeutic application of cannabidiol on UVA and UVB irradiated rat skin. A proteomic study

UV phototherapy used in chronic skin diseases causes redox imbalance and pro-inflammatory reactions, especially in the case of unchanged skin cells. To prevent the harmful effects of UV radiation, cannabidiol (CBD) has been used, which has antioxidant and anti-inflammatory properties. Therefore, the aim of this study was to evaluate the effect of CBD on the metabolism of skin keratinocytes in nude rats exposed to UVA/UVB radiation using a proteomic approach. The results obtained with SDS-PAGE/nanoHPLC/QexactiveOrbiTrap show that exposure of rat’s skin to UVA/UVB radiation, as well as the action of CBD, significantly modified the expression of proteins involved in inflammation, redox balance and apoptosis. UVA/UVB radiation significantly increased the expression and biological effectiveness of the nuclear factor associated with erythroid factor 2 (Nrf2) and cytoprotective proteins being products of its transcriptional activity, including superoxide dismutase (Cu,Zn-SOD) and the inflammatory response (nuclear receptor coactivator-3 and paralemmin-3), while CBD treatment counteracted and partially eliminated these changes. Moreover, cannabidiol reversed changes in the UV-induced apoptotic pathways by modifying anti-apoptotic and pro-apoptotic factors (apoptosis regulator Bcl-2 and transforming growth factor-β). The results show that CBD maintains keratinocyte proteostasis and therefore could be suggested as a protective measure in the prevention of UV-induced metabolic changes in epidermal keratinocytes.

Effect of Sunlight/Ultraviolet Exposure on the Corrosion of Fusion-Bonded Epoxy (FBE) Coated Steel Rebars in Concrete

Currently, highway/railway bridges are designed for the service life of more than 100 y. In such reinforced concrete structures, fusion-bonded epoxy (FBE) coated steel rebars are being used in anticipation of delayed initiation of reinforcement corrosion. However, the FBE steel rebars get exposed to sunlight/ultraviolet rays during prolonged storage and delayed/staged construction. This paper presents microanalytical and electrochemical data (Fourier transform infrared spectroscopy, scanning electron microscopy, energy dispersion x-ray diffraction, and electrochemical impedance spectroscopy) and shows the adverse effects of sunlight/UV exposure on the corrosion resistance of FBE-coated steel reinforcement in concrete construction. Based on tests on steel-mortar specimens, the mechanisms of UV-induced chemical changes, shrinkage, and cracking of FBE coating, and the resulting steel corrosion mechanisms are proposed. Also, the adverse effects of sunlight/UV exposure on chloride threshold and reduction in the service life of FBE-coated steel in cementitious systems are presented. The paper recommends to minimize the exposure of FBE-coated steel rebars to sunlight/UV rays to less than one month.

Syringaresinol Inhibits UVA-Induced MMP-1 Expression by Suppression of MAPK/AP-1 Signaling in HaCaT Keratinocytes and Human Dermal Fibroblasts.

Ultraviolet (UV) irradiation induces detrimental changes in human skin which result in photoaging. UV-induced intracellular changes cause degradation of extracellular matrix (ECM). UV-stimulated cleavage of collagen in ECM occurs via matrix metalloproteinases (MMPs). (±)-syringaresinol (SYR), a phytochemical which belongs to the lignan group of polyphenols, was investigated for its ability to reverse the UVA-induced changes in human HaCaT keratinocytes and dermal fibroblasts (HDFs) in vitro. Effect of SYR on UVA-induced changes was investigated by production and activation of MMPs and its transcriptional upstream effectors; mitogen-activated protein kinases (MAPKs) and pro-inflammatory mediators. Levels of expression were determined using ELISA, RT-PCR and immunoblotting. UVA irradiation stimulated the production of MMP-1 and inhibited collagen production. SYR treatment suppressed MMP-1 and enhanced collagen production in UVA-irradiated HaCaT keratinocytes and HDFs. SYR repressed the UV-induced phosphorylation of p38, ERK and JNK MAPKs in HaCaT keratinocytes while only suppressing JNK phosphorylation in HDFs. In addition, SYR was able to inhibit UVA-induced production of inflammatory cytokines; TNF-α, COX-2, IL-1β and IL-6. Moreover, SYR suppressed the activator protein-1 (AP-1), a heterodimer of phosphorylated transcription factors c-Jun and c-Fos. SYR-treatment decreased nuclear levels of activated c-Fos and c-Jun as a mechanism to inhibit UVA-induced transcriptional activities leading to MMP-1 production. In conclusion, current results demonstrated that SYR could inhibit UVA-induced upregulation of MMP-1 by suppressing MAPK/AP-1 signaling in HaCaT keratinocytes and HDFs. Therefore, SYR was suggested as a potential compound with antiphotoaging properties against UVA-induced skin aging.

Enhancement of Norway spruce bark side-streams: Modification of bioactive and protective properties of stilbenoid-rich extracts by UVA-irradiation

Bark of Norway spruce (Picea abies [L.] Karst.) trees contains large amounts of polyphenolic stilbene glucosides. Stilbene-rich bark extracts could be utilized as e.g., preservatives due to their antioxidative, antifungal, and antibacterial properties. As stilbenes are photosensitive compounds, ultraviolet (UV) light induces a well-known intramolecular cyclization, leading to the formation of substituted phenanthrenes via a dihydro-phenanthrene intermediate. The possible UV-induced changes in the biological activities of the stilbene extracts remain, however, poorly known. Such information is crucial for practical application development. This study elucidated for the first time, how UVA-treatments of spruce bark extracts affect the chemical composition of the extracts, and further change their antimicrobial and antioxidative activities. Norway spruce inner bark was extracted (‘Extract’) and soluble mono- and disaccharides removed using Amberlite XADHP7 (‘Extract XAD’). These extracts were then treated with UVA-light (‘Extract UV’, ‘Extract XAD UV’), and chemical properties analyzed by GC–MS and HP-SEC. The antimicrobial activities of untreated and modified extracts against Staphylococcus aureus, Candida albicans, and Escherichia coli, were evaluated. Additionally, differences in the antioxidant activity between the untreated and UV-treated bark extracts were measured at a total stilbene concentration of 0.5 mg/mL EtOH, using the FRAP and ORAC methods. Also, antioxidant effects were evaluated in a liposome model to assess the ability of the extract to prevent lipid oxidation. Our novel results show that UVA-induced modification of the stilbene-rich inner bark extracts increased the radical scavenging activity. However, UVA-irradiation decreased the capacity of the extracts to prevent lipid oxidation in the liposome system method. The results also indicate a maintained or slightly increased antimicrobial activity after UVA-modification. This study shows that Norway spruce bark stilbenoids and the compounds formed by UVA-irradiation thereof show biological activity, and thus have commercial potential as e.g., preservatives.

The β-Blocker Carvedilol Prevented Ultraviolet-Mediated Damage of Murine Epidermal Cells and 3D Human Reconstructed Skin

The β-blocker carvedilol prevents ultraviolet (UV)-induced skin cancer, but the mechanism is unknown. Since carvedilol possesses antioxidant activity, this study investigated whether carvedilol prevents oxidative photodamage of skin, a precursor event in skin carcinogenesis. The effects of carvedilol, metoprolol (a β-blocker without antioxidant property), and 4-hydroxycarbazole (4-OHC, a carvedilol synthesis intermediate and a free radical scavenger) were compared on UV- or H2O2-induced cell death and reactive oxygen species (ROS) production in murine epidermal JB6 P+ cells. Although carvedilol attenuated cell death, metoprolol and 4-OHC failed to show protective effects. As expected, increased cellular ROS induced by H2O2 or UV was abolished by carvedilol and 4-OHC, but not by metoprolol. Consistently, carvedilol attenuated the formation of UV-induced cyclobutane pyrimidine dimers (CPDs) and release of prostaglandin E2 in JB6 P+ cells. Carvedilol’s activity was further confirmed in full thickness 3D human reconstituted skin, where carvedilol attenuated UV-mediated epidermal thickening, the number of Ki-67 and p53 positive cells as well as CPD formation. Based on pathway-specific Polymerase Chain Reaction (PCR) Array analysis, carvedilol treatment in many cases normalized UV-induced expression changes in DNA repair genes. Thus, carvedilol’s photoprotective activity is not attributed to β-blockade or direct ROS-scavenging capacity, but likely via DNA repair regulation.

A 19 Month Old Male Child with Xeroderma Pigmentosum-A Case Report

Background: Xeroderma Pigmentosum (XP) is a rare autosomal recessive genodermatosis characterized by pigmentary abnormalities, solar skin damage and cutaneous malignancies on sun exposed area of skin and eyes. XP occurs in subjects with molecular defects in the genes involved in nucleotide excision repair (NER) of ultraviolet-induced DNA lesions leading to premature skin and ocular ageing consequent upon cellular apoptosis and other UV-induced degenerative changes. If sufficient DNA damage occurs, there will be cellular transformation and the development of malignancies. Both genetic, as well as environmental factor, play an important role in XP. XP has a >1000-fold increased risk of a cutaneous basal cell or squamous cell carcinoma or malignant melanoma. Case history: In this case report, we mentioned about a 19 month old boy who was diagnosed clinically as a case of Xeroderma Pigmentosum and presented with pigmentary skin changes (generalized hypo and hyper pigmented macule), eye problems, developmental delay, acute respiratory infection and failure to thrive. A multidisciplinary team involving the Pediatrician, Dermatologist and Ophthalmologist evaluated, diagnosed and treated the patient. In this case, XP was diagnosed clinically due to lack of all investigation facilities. This genetic premalignant condition is rarely diagnosed at the district level hospitals in Bangladesh. We report this case to upgrade the knowledge of pediatricians working in the rural areas (primary and secondary level health care facilities) regarding the diagnosis, counseling, treatment modalities and appropriate referral for Xeroderma Pigmentosum. Recommended management should be focused on educating the patient and the parents about effective sun protection and early recognition of cancers. Genetic counseling should be offered for families at risk

UV-induced over time transformation of AgNPs in commercial wound dressings and adverse biological effects on Caenorhabditis elegans

Silver nanoparticles (AgNPs) are frequently used in commercial products; however, the knowledge on their release, environmental modification, and subsequent toxicity is still limited. In this study, we explored the leaking of AgNPs from an enhanced wound dressing under UV radiation as sterilization after use, and the toxic effects were determined using Caenorhabditis elegans (C. elegans). UV radiation was found to cause a series of over time physicochemical changes on the released AgNPs during the exposure: initially the formation of smaller secondary AgNPs (intermediate product), then the merging of Ag particles into structures beyond nanoscale (end product). Tissue-specific distribution and total accumulation of Ag in C. elegans both indicated that full UV treatment enhanced the uptake of AgNPs in the nematodes, which also inclined to release more Ag+. However, the end-product of UV treatment alleviated the neural and reproductive toxicity in C. elegans compared to unexposed particles, while the intermediate product induced more apoptosis in the gonad of the worms. Our data elucidated that UV-induced complex physicochemical changes on the released AgNPs were a crucial factor influencing its toxicity, and suggestions were given accordingly in order to reduce possible environmental threats from used wound dressings. The investigation on nano‑silver wound dressings revealed that special attentions were needed for key environmental factors in both risk assessment and overall regulation of engineered nanomaterial enhanced products.

Effect of UV/ozone treatment on the wettability and adhesion of polymeric systems

ABSTRACT The impact of UV/ozone treatment on the wettability and adhesion of ethylene propylene diene methylene (EPDM) rubber, polyvinyl chloride (PVC), and acrylonitrile butadiene styrene (ABS) was investigated using contact angle measurements, OWRK surface free energy model, standardized adhesion tests, and spectroscopic and microscopic observations. It is found that UV/ozone treatment enhances the wettability of the examined polymers. Also, it considerably improved the adhesion strength of PVC and ABS samples, and shifted their failure modes from adhesive to cohesive. FTIR-ATR characterization showed insignificant changes in the chemical structures of the studied materials. However, SEM observation showed newly-created wrinkles and micro-holes on treated PVC surfaces, and micropores on ABS surfaces. These UV-induced morphological changes on PVC and ABS surfaces increased the surface area which can promote the mechanical interlocking with the adhesive. This explains the improvement of their adhesion strength. Implications of the current study for the processing of strongly bonded polymeric joints are discussed.

Synergistic Cytoprotective Effects of Rutin and Ascorbic Acid on the Proteomic Profile of 3D-Cultured Keratinocytes Exposed to UVA or UVB Radiation.

The combination of ascorbic acid and rutin, often used in oral preparations, due to antioxidant and anti-inflammatory properties, can be used to protect skin cells against the effects of UV radiation from sunlight. Therefore, the aim of this study was to investigate the synergistic effect of rutin and ascorbic acid on the proteomic profile of UVA and UVB irradiated keratinocytes cultured in a three-dimensional (3D) system. Results showed that the combination of rutin and ascorbic acid protects skin cells against UV-induced changes. In particular, alterations were observed in the expression of proteins involved in the antioxidant response, DNA repairing, inflammation, apoptosis, and protein biosynthesis. The combination of rutin and ascorbic acid also showed a stronger cytoprotective effect than when using either compound alone. Significant differences were visible between rutin and ascorbic acid single treatments in the case of protein carboxymethylation/carboxyethylation. Ascorbic acid prevented UV or rutin-induced protein modifications. Therefore, the synergistic effect of rutin and ascorbic acid creates a potentially effective protective system against skin damages caused by UVA and UVB radiation.

The Differences in the Proteome Profile of Cannabidiol-Treated Skin Fibroblasts following UVA or UVB Irradiation in 2D and 3D Cell Cultures.

Cannabidiol (CBD), as the only phytocannabinoid that has no psychoactive effect, has both antioxidant and anti-inflammatory effects, and thus might be suggested as a cytoprotective compound against UV-induced metabolic changes in skin cells. Therefore, the aim of this study was to investigate the level of protective CBD activity by evaluating the proteomic profile of 2D and 3D cultured skin fibroblasts models following exposure to UVA and UVB radiation. The CBD cytoprotective effect against UV-induced damage in 2D and 3D cultured fibroblasts were different. The main alterations focus on the range of cell reaction and involved different proteins associated with various molecular functions. In the 2D cultured cells, following UV radiation, the major changes were associated with proteins involved in antioxidant response and inflammation, while, in the 3D cultured fibroblasts, CBD action against UV induced changes were mainly associated with the activation of signalling pathways. Therefore, the knowledge of the CBD action in a multilayer skin cells model allowed for the prediction of changes in cell-cell interactions and skin cell metabolism. Knowledge about the lower protective effect of CBD in 3D cultured fibroblasts should be taken into account during the design of UV light protection.

Postharvest UV-A and UV-B treatments may cause a transient decrease in grape berry skin flavonol-glycoside contents and total antioxidant capacities

Controlled postharvest abiotic stresses have already been shown to affect the secondary metabolism of fresh produce. We applied broad band ultraviolet (either 312 nm centred UV-B or 355 nm centred UV-A) radiation on harvested berry clusters of the red table grape Emperor, and measured berry skin antioxidant capacities and phenolic profiles 2, 24 and 48 h after these treatments. There was no significant change in the amount of caftaric acid, the dominant phenolic acid component featuring higher UV-B than UV-A absorbing capacity. On the other hand, but both types of UV treatment decreased the amounts of the two major quercetin-glycosides 2 h after irradiation. This effect was temporal, and concentration recovered during berry storage at 20 °C under low intensity light. Berry skin UV-A and UV-B absorbing capacities showed the same, transitional decrease regardless of the wavelength of the irradiation. In the whole data set, antioxidant capacities and quercetin-glycoside content data showed strong and positive correlations. Berry skin peroxidase activity, as visualized with diaminobenzidine-staining showed a transitional increase after 2 h in response to both UV treatments. These data suggest that the observed UV-induced postharvest changes in phenolic metabolites are related to the oxidation of flavonols as peroxidase substrates rather than to direct UV photo-effects.

The glutamate biosynthetic pathway in brain: a novel mechanism of moderate UV-induced neurobehavioral changes.

The glutamate biosynthetic pathway in brain: a novel mechanism of moderate UV-induced neurobehavioral changes.

UV-induced refractive index changes due to silver molecular clusters in photo-thermo-refractive glass

It is shown experimentally that in photo-thermo-refractive glasses the transformation of charged silver subnanosized molecular clusters to neutral state by UV irradiation results in the increase of glass refractive index. Quantum chemistry calculations suggest that such refractive index change is mainly dominated by silver neutral cluster polarizability. In addition to discussion of proposed mechanism, the examples of possible applications are also presented.

Identification of master regulator genes of UV response and their implications for skin carcinogenesis.

Solar UV radiation is a major environmental risk factor for skin cancer. Despite decades of robust and meritorious investigation, our understanding of the mechanisms underlying UV-induced skin carcinogenesis remain incomplete. We previously performed comprehensive transcriptomic profiling in human keratinocytes following exposure to different UV radiation conditions to generate UV-specific gene expression signatures. In this study, we utilized Virtual Inference of Protein Activity by Enriched Regulon (VIPER), a robust systems biology tool, on UV-specific skin cell gene signatures to identify master regulators (MRs) of UV-induced transcriptomic changes. We identified multiple prominent candidate UV MRs, including forkhead box M1 (FOXM1), thyroid hormone receptor interactor 13 and DNA isomerase II alpha, which play important roles in cell cycle regulation and genome stability. MR protein activity was either activated or suppressed by UV in normal keratinocytes. Intriguingly, many of the UV-suppressed MRs were activated in human skin squamous cell carcinomas (SCCs), highlighting their importance in skin cancer development. We further demonstrated that selective inhibition of FOXM1, whose activity was elevated in SCC cells, was detrimental to SCC cell survival. Taken together, our study uncovered novel UV MRs that can be explored as new therapeutic targets for future skin cancer treatment.

Isosbestic Points Do Not Always Work as the Measure to Determine the Oneness of a Reaction as Exemplified by the Photoisomerization of Azobenzene Tethered to Polymer Chains

Even though two isosbestic points are generated in UV-induced changes in UV-vis absorption spectra of films of a polymethacrylate with azobenzene side chains, the corresponding fourth-order derivative spectra disclose the presence of H-aggregate so that the dual process comprised of UV-induced disaggregation and E/Z photoisomerization of non-aggregated species are involved.

The Effect of Sea Buckthorn (Hippophae rhamnoides L.) Seed Oil on UV-Induced Changes in Lipid Metabolism of Human Skin Cells.

Lipids and proteins of skin cells are the most exposed to harmful ultraviolet (UV) radiation contained in sunlight. There is a growing need for natural compounds that will protect these sensitive molecules from damage, without harmful side effects. The aim of this study was to investigate the effect of sea buckthorn seed oil on the redox balance and lipid metabolism in UV irradiated cells formed different skin layers to examine whether it had a protective effect. Human keratinocytes and fibroblasts were subjected to UVA (ultraviolet type A; 30 J/cm2 and 20 J/cm2) or UVB (ultraviolet type B; 60 mJ/cm2 and 200 mJ/cm2, respectively) radiation and treated with sea buckthorn seed oil (500 ng/mL), and the redox activity was estimated by reactive oxygen species (ROS) generation and enzymatic/non-enzymatic antioxidants activity/level (using electron spin resonance (ESR), high-performance liquid chromatography (HPLC), and spectrophotometry). Lipid metabolism was measured by the level of fatty acids, lipid peroxidation products, endocannabinoids and phospholipase A2 activity (GC/MS (gas chromatography/mass spectrometry), LC/MS (liquid chromatography/mass spectrometry), and spectrophotometry). Also, transcription factor Nrf2 (nuclear erythroid 2-related factor) and its activators/inhibitors, peroxisome proliferator-activated receptors (PPAR) and cannabinoid receptor levels were measured (Western blot). Sea buckthorn oil partially prevents UV-induced ROS generation and enhances the level of non-enzymatic antioxidants such as glutathione (GSH), thioredoxin (Trx) and vitamins E and A. Moreover, it stimulates the activity of Nrf2 leading to enhanced antioxidant enzyme activity. As a result, decreases in lipid peroxidation products (4-hydroxynonenal, 8-isoprostaglandin) and increases in the endocannabinoid receptor levels were observed. Moreover, sea buckthorn oil treatment enhanced the level of phospholipid and free fatty acids, while simultaneously decreasing the cannabinoid receptor expression in UV irradiated keratinocytes and fibroblasts. The main differences in sea buckthorn oil on various skin cell types was observed in the case of PPARs—in keratinocytes following UV radiation PPAR expression was decreased by sea buckthorn oil treatment, while in fibroblasts the reverse effect was observed, indicating an anti-inflammatory effect. With these results, sea buckthorn seed oil exhibited prevention of UV-induced disturbances in redox balance as well as lipid metabolism in skin fibroblasts and keratinocytes, which indicates it is a promising natural compound in skin photo-protection.

The Protective Role of Astaxanthin for UV-Induced Skin Deterioration in Healthy People-A Randomized, Double-Blind, Placebo-Controlled Trial.

Skin is a major safeguard tissue in humans. Because biological barrier function is deteriorated by several kinds of stresses including exposure to ultra-violet (UV) rays, the protection and treatment of skin conditions by dietary supplements are important. We therefore evaluated the effects of dietary supplementation with an algal food-derived antioxidant, astaxanthin, on UV-induced skin deterioration. Twenty-three healthy Japanese participants were recruited to a 10-week double-blind placebo-controlled study. They were assigned to the astaxanthin group supplemented with a capsule containing 4 mg of astaxanthin or the placebo group. To assess the protective role of astaxanthin for UV-induced skin deterioration, we determined the minimal erythema dose (MED) and analyzed UV-induced changes of moisture and transepidermal water loss (TEWL) at baseline and after 9 weeks of supplementation. Subjective skin conditions were assessed by the visual analog scale. The astaxanthin group showed increased MED compared with placebo. In addition, the astaxanthin group had a reduced loss of skin moisture in the irradiated area compared with placebo. Subjective skin conditions for “improvement of rough skin” and “texture” in non-irradiated areas were significantly improved by astaxanthin. Astaxanthin seems protective against UV-induced skin deterioration and helps maintain healthy skin in healthy people.