UVB-induced Photodamage Research Articles

Jujube and green tea extracts protect human fibroblast cells against UVB-mediated photo damage and MMP-2 and MMP-9 production.

Oxidative stress and ultraviolet B (UVB) irradiation are known as principal inducers of DNA damage and modulators of gene expression in aging process and skin photoaging, which are associated with upregulation of matrix metalloproteinases (MMPs). Because of the antioxidant capacity of jujube and green tea, we decided to determine their protective effects of human fibroblast cells against UVB-induced photo-damage and reduction of MMP-2 and MMP-9 expression. We exposed human fibroblast cells to different doses of UVB (0-20 mJ/cm2) with or without different concentrations of jujube and green tea extracts. Cell viability was assessed using MTT assay. Total antioxidant capacity and free radical scavenging activity of cell supernatant were assessed using FRAP and DPPH methods, respectively. The concentrations of MMP-2 and MMP-9 in the samples were determined by ELISA kits. Fibroblast cells viability, 24 hr after UVB irradiation, reduced about 70% compared to the controls. Pre-treatment of the cells with jujube extract (8 mg/ml) increased the cell viability by almost 85% while green tea (0.5 mg/ml) protected the irradiated cells by 71%. Also, MMP-2 and MMP-9 content decreased in a concentration-dependent manner in the cells pre-treated with jujube and green tea extracts. These data suggest that jujube and green tea could be useful to attenuate solar UVB light-induced oxidative stress and skin photoaging and can be suggested as a potential candidate for the development of new anti-UVB medicines and cosmetic products.

Areca nut procyanidins prevent ultraviolet light B-induced photoaging via suppression of cyclooxygenase-2 and matrix metalloproteinases in mouse skin

Chronic exposure to solar ultraviolet (UV) light induces photoaging in human skin. Our previous results have shown that areca nut procyanidins (ANPs) have antioxidant capacity and possess potential anti-inflammatory effects. Here, we aimed to investigate the effect of ANPs on UVB-induced photoaging. In the present study, dorsal skin of CD-1 mice was exposed to UVB at a minimal erythema dose (130 mJ/cm2) throughout a 3-week period. The effects of ANPs and epigallocatechin-3-gallate (EGCG), a polyphenolic constituent of green tea, on UVB-induced photoaging were compared. The results show that oral administration of ANP prevented UVB-induced photoaging, indicated by epidermal thickness and collagen disorientation, and inhibited UVB-induced expression of cyclooxygenase-2 and matrix metalloproteinases (MMPs), such as MMP-2, MMP-9, and TIMP1. The protective potential of ANP on UVB-induced photodamage was comparable to that of EGCG. These data suggest that ANP could be useful as a dietary supplement to attenuate solar UVB-induced premature skin aging.

Protective effect of diphlorethohydroxycarmalol isolated from Ishige okamurae against UVB-induced damage in vitro in human dermal fibroblasts and in vivo in zebrafish

Excessive exposure to ultraviolet (UV) irradiation from the sun is the primary environmental factor that causes aging of the skin. Most skin diseases caused by UV are attributed to UVB (280–320 nm). The purpose of this study is to investigate the protective effect of diphlorethohydroxycarmalol (DPHC), isolated from the marine brown alga, Ishige okamurae, against UVB-induced photodamage using both in vitro and in vivo models. Results indicate that DPHC remarkably inhibited commercial collagenase and elastase activities. It also reduced intracellular levels of ROS, improved cell viability and collagen content in UVB-irradiated human dermal fibroblasts (HDF cells). In addition, DPHC significantly inhibited activities of intracellular collagenase and elastase and reduced the expression of matrix metalloproteinases (MMPs) and pro-inflammatory cytokines. These events occurred through regulation of nuclear factor kappa B (NF-κB), activator protein 1 (AP-1), and mitogen-activated protein kinases (MAPKs) signaling pathways in UVB-irradiated HDF cells. Furthermore, DPHC also protected against in vivo photodamage by decreasing cell death through reducing lipid peroxidation and inflammatory response via decreasing ROS levels in UVB-irradiated zebrafish. In conclusion, DPHC has strong in vitro and in vivo photoprotective effects and has the potential to be used as an ingredient in pharmaceutical and cosmeceutical industries.

Antioxidant cinnamaldehyde attenuates UVB-induced photoaging

BackgroundUltraviolet (UV) irradiation disrupts skin through several deleterious actions, such as induction of reactive oxygen species (ROS), DNA damage, and collagen degradation. Cinnamaldehyde (CIN) is a major constituent of the cinnamon and it possesses potent antioxidative activity; however, it is unclear whether CIN is capable of inhibiting the adverse effects of UVB. ObjectiveTo investigate protective effects of CIN against UVB-induced photodamage. MethodsHaCaT keratinocytes were pretreated with CIN, irradiated with UVB, and assessed for the ROS production by flow cytometry and for the DNA damage by ELISA. As in vivo mouse model, Hos:HR-1 hairless mice were treated with ointments containing DMSO or CIN and irradiated multiple times with UVB. After 10 weeks of irradiation, wrinkle formation, epidermal thickness, infiltrating cell number, malondialdehyde amount, collagen amount, MAP kinase signaling, and related gene expressions (Hmox1, Col1a1, Mmp1a, and Mmp13) were analyzed. ResultsCIN significantly reduced the ROS production and accelerated the repair of DNA damage pyrimidine(6-4)pyrimidone photoproducts in UVB-irradiated human keratinocytes in vitro. In the mouse model, topical application of CIN significantly inhibited wrinkle formation, epidermal hyperplasia, and dermal inflammatory cell infiltration. The antioxidative process was significantly promoted in the CIN-applied site, as evidenced by upregulation of the antioxidative enzyme Hmox1 as well as the reduced accumulation of malondialdehyde. In addition, topical application of CIN normalized the UVB-induced collagen/Col1a1 downregulation and the UVB-induced Mmp13 upregulation, implying the prevention of UVB-induced collagen degradation. ConclusionsCIN and CIN-containing herbal agents may exert potent protective effects against UVB exposure on skin.

Transglutaminase 3 is expressed in basal cell carcinoma of the skin.

Transglutaminase 3 (TG3) belongs to a family of Ca2+-dependent enzymes which catalyse protein crosslinking. TG3 is important for proper development of the skin and hair shaft, and knock-out mice for the Tgm3 gene are sensitive to UVB-induced photodamage due to aberrations in cornified envelope formation. Loss of TG3 is reported in head and neck and oesophageal squamous cell carcinoma, yet, its expression in skin cancer has not been studied. The aim of the present study was to analyse the expression pattern of TG3 in skin cancer. TG3 expression was investigated based on immunohistochemical staining of a tissue micro-array of different types of skin cancer, as well as meta-analysis of public gene array data. Our findings demonstrated that TG3 is normally expressed in spinous/granular layers of the epidermis, but is absent in melanocytes as well as melanoma samples. As expected, its expression was absent in poorly differentiated squamous cell carcinoma of the skin. Surprisingly, we show that samples of basal cell carcinoma demonstrated strong staining for TG3 both in the cytoplasm and nucleus. Furthermore, at the mRNA level, the expression pattern of TGM3 was crucially altered in BCC, but not other types of skin cancer. These findings lead to new questions regarding TG3 involvement in basal cell carcinoma tumourigenesis. Moreover, the expression pattern of TG3 renders it a potential specific marker for basal cell carcinoma diagnosis.

Ethanol extract of Gynura bicolor (GB) protects against UVB-induced photodamage of skin by inhibiting P53-mediated Bcl-2/BAX/Caspase-3 apoptosis pathway.

To investigate the protective effect of ethanol extract of Gynura bicolor (GB) against UVB-induced photodamage of skin and the possible mechanisms. DPPH (1,1-diphenyl-2-pico radical) test was used to detect the antioxidant capacity of ethanol extract of Gynura bicolor (GB). The protective effects of GB against UVB irritation were detected both in Hacat cells and photodamage rat models. UVB irradiation could inhibit viability and induce apoptosis of Hacat cells in a dose-dependent manner. The pretreatment of Hacat cells by GB could obviously reverse the effects in a dose-dependent manner. The mRNA and protein expressions of p53, Bax, caspase-3 were increased, while anti-apoptotic protein Bcl-2 was decreased and this effect could be reversed by GB pretreatment in a dose-dependent manner. In vivo, the application of GB could alleviate the skin damage of SD rats and improve the superficial inflammation of the dermis as well as inhibit the expressions of P53 and Caspase-3 induced by UVB irradiation. Ethanol extract of Gynura bicolor could protect the photodamage of human Hacat keratinocytes and SD rats against UVB irradiation by inhibiting P53-mediated Bcl-2/ BAX/Casaspe-3 apoptosis pathway.

Protective Effects of Indole 3-Acetonitrile-4-Methoxy-2-S-β-d-Glucopyranoside From Nasturtium officinale R. Br. Against Ultraviolet B-Induced Photodamage in Normal Human Dermal Fibroblasts

Ultraviolet radiation induces skin photoaging, which is associated with the elevation of matrix metalloproteinase-1 (MMP-1) and the decrease of procollagen. Nasturtium officinale plays a well-known role in the treatment of sulfur-containing compounds and their important role in protecting human health. However, their skin protective activity toward UVB-induced photodamage remains unclear. In the present study, we investigated the protective effect of indole 3-acetonitrile-4-methoxy-2- S-β-d-glucopyranoside (IAMG) from N. officinale on UVB-irradiated normal human dermal fibroblasts (NHDF). Our results show that IAMG enhanced NHDF cell migration. The UVB-induced increases in MMP-1 and decrease in type I procollagen were ameliorated by IAMG treatment. Taken together, our data strongly suggest that IAMG from N. officinale could reduce UVB-induced photodamage.

Antiphotoaging and Antimelanogenesis Properties of Ginsenoside C-Y, a Ginsenoside Rb2 Metabolite from American Ginseng PDD-ginsenoside.

Ginsenosides are compounds responsible for the primary pharmacological effects of American ginseng. Compound-Y (C-Y) is a minor ginsenoside and a metabolite of Panax ginseng. In this study, we investigated the protective effect of ginsenoside UVB-irradiated NHDFs and its potential for use as an antihyperpigmentation agent through ginsenoside C-Y as a functional food and cosmetic ingredient. Ginsenoside C-Y is a natural antioxidant isolated from the American ginseng PDD-ginsenoside. Our data showed that ginsenoside C-Y block UVB-exposed ROS, restrict MMP-1 production and promote procollagen type I synthesis. Interestingly, ginsenoside C-Y suppresses UVB-exposed VEGF, and TNF-α secretion, could be related with NFAT signal path. Ginsenoside C-Y has exhibited photoaging effects by increasing TGF-β1 level, fortifying Nrf2 nuclear translocation and restricting AP-1 and MAPK phosphorylation. Assessment of the melanogenic response indicated that ginsenoside C-Y inhibited melanin secretion and tyrosinase activity and decreased melanin content in Melan-a and zebrafish embryos. These results suggest that ginsenoside C-Y can be used as a potential botanical agent to protect premature skin from UVB-induced photodamage and prevent skin hyperpigmentation.

Photoprotective properties of combined extracts fromDiospyros lotusleaves andCurcuma longarhizomes against chronic UVB‐induced photodamage

The synergistic effects of combined ethanolic extracts of Diospyros lotus leaves (DLE) and Curcuma longa rhizomes (CLE) were investigated for their protective effects on chronic Ultraviolet-B (UVB)-induced skin photodamage in SHK-1 mice. The degree of protection was measured by using biochemical parameters such as malondialdehyde, reduced glutathione, superoxide dismutase, catalase, Akt activation, and nuclear factor (erythroid-derived 2)-like 2 (Nrf2) activities, collagen degradation among others. DLE, CLE, and DLE/CLE demonstrated significant photodamage protection by upregulating endogenous antioxidant in mice skin through the activation of Akt and Nrf2 activities; prevented epidermal hyperplasia; mast cell infiltration into the skin and collagen degradation. The effects of the combined extract were greater than the effects of the single extracts. Also, the synergistic effects of DLE/CLE were comparable to that of standard drug, ascorbic acid. This study suggests the synergistic protective role of DLE/CLE in the treatment UVB-induced photodamage. Practical application The use of synthetic antioxidant products to prevent oxidative-related stress, especially from UV radiations is frequently accompanied with severe side effects. Therefore, the search for natural antioxidants is of utmost importance. Polyphenols are of great interest due to their antioxidant properties and small molecular weight that permits them to penetrate the skin. Diospyros lotus (rich in myricitrin) and Curcuma longa rhizomes (rich in curcumin) are both edible plants. This research investigates the synergetic effects of extracts of both plants against chronic UVB-induced oxidative stress. Data obtained from this study shed light on using plant-based products both alone and in synergy as potential functional foods and nutraceuticals for the prevention of UVB-induced oxidative stress. The results of this research could serve as a base for further research on these extracts as a source of antioxidant and promotes the usage of these plants on a large scale as functional food materials.

Helianthus annuus L. flower prevents UVB-induced photodamage in human dermal fibroblasts by regulating the MAPK/AP-1, NFAT, and Nrf2 signaling pathways.

Excessive ultraviolet radiation usually causes skin photoaging, inflammation, and even photocarcinogenesis. UV radiation-generated reactive oxygen species (ROS) are a major contributing factor to photodamage. The flowers of Helianthus annuus L. have been reported to possess strong anti-inflammatory and antioxidant activity. However, there are few reports on the use of H. annuus L. to relieve UVB-induced photoaging. In this study, we evaluated the protective effect of a 50% ethanol extract of H. annuus L. flower (HAF) against UVB-induced photodamage using normal human dermal fibroblasts. The secretion of ROS, interleukin-6 (IL-6), vascular endothelial growth factor (VEGF), matrix metalloproteinases (MMPs), procollagen type I, and transforming growth factor-β1 (TGF-β1) was measured with kits. The messenger RNA levels of COX-2, iNOS, and TGF-α were measured by RT-PCR. The AP-1, MAPK, NFAT, and Nrf2 pathways were investigated by Western blot analysis. HAF extract significantly blocked UVB-induced ROS and MMP (MMP-1 and MMP-3) production and procollagen type I reduction. Further study demonstrated that the photoaging inhibitory actions were related to promotion of Nrf2 nuclear translocation, upregulation of TGF-β1 level, and downregulation of AP-1 and MAPK phosphorylation. Importantly, HAF effectively inhibited UVB-induced VEGF and inflammatory cytokines such as IL-6, COX-2, iNOS, and TNF-α secretion, which might be involved in the regulation of the NFAT signaling pathway. Our results indicate that HAF is a useful botanical source protecting against UVB-mediated skin photodamage.

Graphene Oxide-Mediated Protection from Photodamage.

This Letter presents the unique properties of graphene oxide (GO) as a multitask material protecting from UVB-induced photodamage. Three mechanisms of GO action on fibroblast in vitro cultures are verified here: physical - a barrier blocking UV radiation; chemical - antioxidative activity; and biological - activation of cellular antioxidative defense. The changes in GO physicochemical properties appearing due to UVB exposure underpin the observed UV protection phenomena. The results reveal the simultaneous occurrence of two opposed processes, i.e., under small doses of UVB, the tested material undergoes oxidation and sp2 network rebuilding. In the vicinity of the GO surface, the locally triggered high temperature is responsible for a reduction process, while strong oxidative agents such as OH radicals cause parallel GO oxidation. This phenomenon is enabled thanks to the exceptional properties of carbonaceous materials. As a consequence, GO turns out to be a multitask UV protector increasing fibroblast survival.

Caffeic acid prevents UVB radiation induced photocarcinogenesis through regulation of PTEN signaling in human dermal fibroblasts and mouse skin

Previously, we proved that caffeic acid (CA), a major dietary phenolic acid, prevents skin carcinogenesis by modulating inflammatory signaling in mouse skin. However, the actual mechanisms of CA against UVB (280–320 nm) induced photocarcinogenesis remains unclear. The present results confirms that CA significantly inhibits single UVB-induced CPDs formation, oxidative DNA damage, ROS generation and frequency of apoptotic cell death in human dermal fibroblasts (HDFa). Furthermore, CA prevents UVB-induced expression of PI3K and AKT kinases through activation of PTEN which subsequently promotes XPC dependant NER proteins such as XPC, XPE, TFIIH (p44) and ERCC1 in HDFa cells and mouse skin tissue. Further, CA directly activates PTEN through hydrogen bond and hydrophobic interactions. Taken together, these findings suggest that CA prevents UVB-induced photodamage through the activation of PTEN expression in human dermal fibroblasts and mouse skin.

Protective effect of exogenous biliverdin against ultraviolet B-induced photodamage in HaCaT cells

Objective To evaluate the protective effect of exogenous biliverdin on ultraviolet B (UVB) -radiated HaCaT cells, and to explore its mechanism. Methods Cultured HaCaT cells were divided into 5 groups: control group receiving no treatment, UVB group irradiated with 30 mJ/cm2 UVB, 3 biliverdin+ UVB groups treated with 100 nmol/L, 1 μmol/L and 10 μmol/L biliverdin respectively for 1 hour followed by 30 mJ/cm2 UVB radiation. After 24-hour treatment, changes in the morphology of HaCaT cells were observed, and cell counting kit 8 (CCK8) assay was performed to determine cell survival rates in the above groups. Western blot analysis was conducted to measure the protein expression of antioxidant signaling molecule NF-E2-related factor-2 (Nrf-2) and the photodamage signaling molecules matrix metalloproteinase-1 (MMP-1) and MMP-3. Results CCK8 assay showed that the survival rate of HaCaT cells was significantly lower in the UVB group than in the control group (P < 0.05) , but significantly higher in the 100-nmol/L, 1-μmol/L and 10-μmol/L biliverdin+ UVB groups than in the UVB group (all P < 0.05) . Western blot analysis showed that the protein expression of MMP-1 and MMP-3 was significantly higher in the UVB group (1.150 ± 0.187, 0.979 ± 0.054 respectively) than in the control group (0.116 ± 0.018, 0.636 ± 0.035 respectively; both P < 0.01) , but was significantly lower in the 100-nmol/L, 1-μmol/L and 10-μmol/L biliverdin + UVB groups (MMP-1: 0.825 ± 0.139, 0.313 ± 0.047 and 0.286 ±0.036 respectively; MMP-3: 0.888 ± 0.017, 0.672 ± 0.042 and 0.569 ± 0.037 respectively) than in the UVB group (all P < 0.05) . Moreover, the protein expression of Nrf-2 was significantly lower in the UVB group (0.906 ± 0.034) than in the control group (1.242 ± 0.141, P < 0.05) , but significantly higher in the 100-nmol/L, 1-μmol/L and 10-μmol/L biliverdin+ UVB groups (1.556 ± 0.112, 1.897 ± 0.234 and 2.035 ± 0.274) than in the UVB group (all P < 0.01) . Conclusion Exogenous biliverdin protects against UVB-induced photodamage in HaCaT cells, which may be associated with Nrf-2 antioxidant signaling pathway. Key words: Keratinocytes; Ultraviolet rays; Biliverdin; Matrix metalloproteinase 1; Matrix metallo-proteinase 3; NF-E2-related factor 2; HaCaT cells

RETRACTED ARTICLE: Therapeutic effect of molecular hydrogen in corneal UVB-induced oxidative stress and corneal photodamage

The aim of this study is to examine whether molecular hydrogen (H2) is able to reduce oxidative stress after corneal damage induced by UVB irradiation. We previously found that UVB irradiation of the cornea caused the imbalance between the antioxidant and prooxidant enzymes in the corneal epithelium, followed by the imbalance between metalloproteinases and their physiological inhibitors (imbalances in favour of prooxidants and metalloproteinases) contributing to oxidative stress and development of the intracorneal inflammation. Here we investigate the effect of H2 dissolved in PBS in the concentration 0.5 ppm wt/vol, applied on rabbit corneas during UVB irradiation and healing (UVB doses 1.01 J/cm2 once daily for four days). Some irradiated corneas remained untreated or buffer treated. In these corneas the oxidative stress appeared, followed by the excessive inflammation. Malondiladehyde and peroxynitrite expressions were present. The corneas healed with scar formation and neovascularization. In contrast, in H2 treated irradiated corneas oxidative stress was suppressed and malondiladehyde and peroxynitrite expressions were absent. The corneas healed with the restoration of transparency. The study provides the first evidence of the role of H2 in prevention of oxidative and nitrosative stress in UVB irradiated corneas, which may represent a novel prophylactic approach to corneal photodamage.

Enhancement of Protective Effects of Radix Scutellariae on UVB-induced Photo Damage in Human HaCaT Keratinocytes.

Radix Scutellariae (RS) has long been used in the treatment of inflammatory and allergic diseases. Its main flavonoids, baicalin (BG) and wogonoside (WG), can be hydrolyzed into their corresponding aglycones, baicalein (B) and wogonin (W). In this study, we developed a safe and effective method of transforming these glycosides using Peclyve PR. The transformation rate of BG and WG reached 98.5 and 98.1%, respectively, with 10% enzyme at 40°C for 60h. Furthermore, we compared the anti-photoaging activity of RS before and after enzyme treatment, as well as their respective main components, in UVB-irradiated HaCaT cells. Results found that enzyme-treated RS (ERS) appeared to be much better at preventing UVB-induced photoaging than RS. ERS significantly inhibited the upregulation of matrix metalloproteinase-1 and IL-6 caused by UVB radiation by inactivating the MAPK/AP-1 and NF-κB/IκB-α signaling pathways. ERS treatment also recovered UVB-induced reduction of procollagen type I by activating the TGF-β/Smad pathway. In addition, ERS exhibited an excellent antioxidant activity, which could increase the expression of cytoprotective antioxidants such as HO-1 and NQ-O1, by facilitating Nrf2 nuclear transfer. These findings demonstrated that the photoprotective effects of RS were significantly improved by enzyme-modified biotransformation.

Pterostilbene protects against UVB-induced photo-damage through a phosphatidylinositol-3-kinase-dependent Nrf2/ARE pathway in human keratinocytes

ABSTRACTObjective: Ultraviolet B (UVB) irradiation is the initial etiological factor for various skin disorders, including erythema, sunburn, photoaging, and photocarcinogenesis. Pterostilbene (Pter) displayed remarkable antioxidant, anti-inflammatory, and anticarcinogenic activities. This study aimed to investigate the effective mechanism of Pter against UVB-induced photodamage in immortalized human keratinocytes.Methods: Human keratinocytes were pretreated with Pter (5 and 10 μM) for 24 h prior to UVB irradiation (300 mJ/cm2). Harvested cells were analyzed by MTT, DCFH-DA, comet, western blotting, luciferase promoter, small interference RNA transfection, and quantitative real-time polymerase chain reaction assay.Results: Pter significantly attenuated UVB-induced cell death and reactive oxygen species (ROS) generation, and effectively increased nuclear translocation of NF-E2-related factor-2 (Nrf2), expression of Nrf2-dependent antioxidant enzymes, and DNA repair activity. Moreover, the protective effects of Pter were abolished by small interference RNA-mediated Nrf2 silencing. Furthermore, Pter was also found to induce the phosphorylation of Nrf2 and the known phosphatidylinositol-3-kinase (PI3K) phosphorylated kinase, Akt. The specific inhibitor of PI3K, LY294002, successfully abrogated Pter-induced Nrf2 phosphorylation, activation of Nrf2-antioxidant response element pathway, ROS scavenging ability, and DNA repair activity.Conclusion: The present study indicated that Pter effectively protected against UVB-induced photodamage by increasing endogenous defense mechanisms, scavenging UVB-induced ROS, and aiding in damaged DNA repair through a PI3K-dependent activation of Nrf2/ARE pathway.

Lycium barbarum polysaccharide protects human keratinocytes against UVB-induced photo-damage

Ultraviolet B (UVB) irradiation plays a key role in skin damage, which induces oxidative and inflammatory damages, thereby causing photoaging or photocarcinogenesis. Lycium barbarum polysaccharide (LBP), the most biologically active fraction of wolfberry, possesses significant antioxidative and anti-inflammatory effects on multiple tissues. In the present study, the photoprotective effects and potential underlying molecular mechanisms of LBP against UVB-induced photo-damage were investigated in immortalized human keratinocytes (HaCaT cells). The data indicated that pretreatment with LBP significantly attenuated UVB-induced decrease in cell viability, increase in ROS production and DNA damage. LBP also significantly suppressed UVB-induced p38 MAPK activation, and subsequently reversed caspase-3 activation and MMP-9 expression. Notably, LBP was found to induce Nrf2 nuclear translocation and increase the expression of Nrf2-dependent ARE target genes. Furthermore, the protective effects of LBP were abolished by siRNA-mediated Nrf2 silencing. These results showed that the antioxidant LBP could partially protect against UVB irradiation-induced photo-damage through activation of Nrf2/ARE pathway, thereby scavenging ROS and reducing DNA damage, and subsequently suppressing UVB-induced p38 MAP pathway. Thus, LBP can be potentially used for skincare against oxidative damage from environmental insults.

Proteomic Analysis and Functional Studies of Baicalin on Proteins Associated with Skin Cancer.

Abundant evidence supports the key role of ultraviolet radiation (UVR) in skin cancer development. The human skin, especially the epidermal layer, is the main defense against UV radiation. Baicalin is a major bioactive component of Scutellaria baicalensis Georgi, a plant which has been found to exhibit antitumor activity. The anticarcinogenic mechanism of baicalin is not completely understood. We have reported that baicalin inhibited UVB-induced photo-damage and apoptosis in HaCaT cells (human skin keratinocytes). The aim of the present study is to investigate the cellular gene targets responsible for baicalin's antitumor activity by performing two-dimensional electrophoresis liquid chromatography-mass spectrometry/mass spectrometry (2-DE LC-MS/MS) with HaCaT cells following UVB and baicalin exposure. Two-DE for protein separation was performed, followed by matrix-assisted laser desorption/ionization mass spectrometry and database searches. Nucleophosmin (NPM)-specific siRNA was designed and synthesized, and the small interfering RNA was transfected into skin squamous cancer A431 cells to knockdown the NPM expression. Proliferation and cell cycle status were assessed by CCK8 and flow cytometric analyses, respectively. We have identified 38 protein spots that are differentially expressed in HaCaT cells exposed to baicalin and/or UVB irradiation These proteins are involved in detoxification, proliferation, metabolism, cytoskeleton and motility. In particular, we found several proteins that have been linked to tumor progression and resistance, such as NPM.Baicalin treatment reduced the cellular proliferation rate and induced arrest during the S-phase of the cell cycle in A431 cells. NPM1 silencing significantly enhanced the effect of baicalin. Our data indicated that baicalin results in the significant inhibition of tumor growth in the A431 cell line, which may be associated with the regulation of the NPM gene expression.

Role of p53 in silibinin-mediated inhibition of ultraviolet B radiation-induced DNA damage, inflammation and skin carcinogenesis.

Non-melanoma skin cancers (NMSC) are a growing problem given that solar ultraviolet B (UVB) radiation exposure is increasing most likely due to depletion of the atmospheric ozone layer and lack of adequate sun protection. Better preventive methods are urgently required to reduce UV-caused photodamage and NMSC incidence. Earlier, we have reported that silibinin treatment activates p53 and reduces photodamage and NMSC, both in vitro and in vivo; but whether silibinin exerts its protective effects primarily through p53 remains unknown. To address this question, we generated p53 heterozygous (p53+/-) and p53 knockout (p53-/-) mice on SKH-1 hairless mouse background, and assessed silibinin efficacy in both short- and long-term UVB exposure experiments. In the chronic UVB-exposed skin tumorigenesis study, compared to p53+/+ mice, p53+/- mice developed skin tumors earlier and had higher tumor number, multiplicity and volume. Silibinin topical treatment significantly reduced the tumor number, multiplicity and volume in p53+/+ mice but silibinin' protective efficacy was significantly compromised in p53+/- mice. Additionally, silibinin treatment failed to inhibit precursor skin cancer lesions in p53-/- mice but improved the survival of the mice. In short-term studies, silibinin application accelerated the removal of UVB-induced DNA damage in p53+/+ mice while its efficacy was partially compromised in p53-/- mice. Interestingly, silibinin treatment also inhibited the UVB-induced inflammatory markers in skin tissue. These results further confirmed that absence of the p53 allele predisposes mice to photodamage and photocarcinogenesis, and established that silibinin mediates its protection against UVB-induced photodamage, inflammation and photocarcinogenesis partly through p53 activation.

Potential for tyndalized Lactobacillus acidophilus as an effective component in moisturizing skin and anti-wrinkle products.

It is widely accepted that ultraviolet (UV) irradiation induces skin damage. In the present study, a UVB-induced hairless mouse model of skin photoaging was developed to determine whether tyndalized Lactobacillus acidophilus was able to significantly enhance the repair of photodamaged skin. To evaluate the effects of tyndalized L. acidophilus on UVB-induced skin-wrinkle formation in vivo, HR-1 hairless male mice were exposed to UVB radiation and orally administered tyndalized L. acidophilus. Compared with the control group, the UVB irradiation mice displayed a significant increase in transepidermal water loss and a reduction in skin hydration. In mice with UVB-induced photodamage, the effacement of the fine wrinkles by tyndalized L. acidophilus was correlated with dermal collagen synthesis, accompanied by histological changes. Furthermore, western blotting was performed to investigate the protein expression levels of matrix metalloproteinases (MMPs) and mitogen-activated protein kinase. Notably, orally administered tyndalized L. acidophilus reduced the expression levels of MMP-1 and MMP-9. Based upon the aforementioned results, it was determined that tyndalized L. acidophilus effectively inhibited the wrinkle formation induced by UVB irradiation, and that this may be attributed to the downregulation of MMPs. Therefore, tyndalized L. acidophilus may be considered a potential agent for preventing skin photoaging and wrinkle formation.