Dandelion Extracts Protect Human Skin Fibroblasts from UVB Damage and Cellular Senescence

The phytochemical and pharmacological profile of dandelion

Dandelion (Taraxacum genus), a perennial herb belonging to the Asteraceae family is widely distributed in hillside grasslands, roadsides, fields, and river beaches in middle and low-altitude areas. It has a long history of traditional Chinese medicine usage as a heat-clearing and detoxifying agent, often consumed as tea or vegetable. Multiple pharmacological studies have demonstrated the antiviral, antibacterial, anti-inflammatory, immune-regulating, antioxidant, anti-tumor, and other effects of the Taraxacum genus. Bioactive compounds associated with these effects include triterpenes and their saponins, phenolic acids, sterols and their glycosides, flavonoids, organic acids, volatile oils, and saccharides.

Bio-active metabolites from Chinese Medicinal Herbs for treatment of skin diseases

Skin diseases have become serious issues to human health and affect one-third of the world's population according to the World Health Organisation (WHO). These consist of internal (endogenous) and external (exogenous) factors referring to genetics, hormones, and the body's immune system, as well as environmental situations, UV radiation, or environmental pollution respectively. Generally, Western Medicines (WMs) are usually treated with topical creams or strong medications for skin diseases that help superficially, and often do not treat the root cause. The relief may be instant and strong, sometimes these medicines have adverse reactions that are too strong to be able and sustained over a long period, especially steroid drug type. Chinese Medicinal Herbs (CMHs) are natural resources and relatively mild in the treatment of both manifestation and the root cause of disease. Nowadays, CMHs are attractive to many scientists, especially in studying their formulations for the treatment of skin diseases.

METHODS

The methodology of this review was searched in nine electronic databases including WanFang Data, PubMed, Science Direct, Scopus, Web of Science, Springer Link, SciFinder, and China National Knowledge Infrastructure (CNKI), without regard to language constraints. All eligible studies are analysed and summarised.

RESULTS

Based on the literature findings, some extracts or active metabolites divided from CMHs, including Curcumin, Resveratrol, Liquorice, Dandelions, Cortex Moutan, and Calendula officinalis L., are effective for the treatment and prevention of skin diseases because of a wide range of pharmacological activities, e.g. anti-bacterial, anti-microbial, anti-virus, and anti-inflammation to enhance the body's immune system. It is also responsible for skin whitening to prevent pigmentation and premature ageing through several mechanisms, such as regulation or inhibition of nuclear factor kappa B (IκB/NF-κB) signalling pathways.

CONCLUSION

This is possible to develop CMHs, such as Curcumin, Resveratrol, Liquorice, Dandelions, Cortex Moutan and Calendula officinalis L. The ratio of multiple CMH formulations and safety assessments on human skin diseases required studying to achieve better pharmacological activities. Nano formulations are the future investigation for CMHs to combat skin diseases.

Mechanistic Role of Methanolic Extract of Taraxacum officinale Roots as Cardioprotective Against Ischemia-Reperfusion Injury-Induced Myocardial Infarction in Rats

Taraxacum officinale play an important role in the prophylaxis and treatment of cardiovascular disease (CVD). Taraxacum officinale is proven as promising antioxidant in earlier studies and one of its constituent "cichoric acid" is shown to have vasorelaxant property. Therefore, present study mainly designed to investigate the cardioprotective effects of Taraxacum officinale against ischemia-reperfusion injury (I/R injury)-induced myocardial dysfunction in rats. This study not only explored the overall cardioprotective potential but also tried to explore its molecular mechanism using pharmacological inhibition via L-NAME and glibenclamide. Pretreatment of methanolic extract of Taraxacum officinale significantly attenuated (p < 0.001) increased levels of lactate dehydrogenase (LDH), creatine kinase (CK), infarct size, and thiobarbituric acid reactive substance (TBARS), while it increased the reduced levels of protein content, glutathione (GSH), and catalase (CAT) activity. Results showed that pretreatment with methanolic extract of Taraxacum officinale provides cardioprotection against I/R induced myocardial dysfunction, at least, may be mediated through the endogenous release of nitric oxide.

Monochrome Camera Conversion: Effect on Sensitivity for Multispectral Imaging (Ultraviolet, Visible, and Infrared)

Conversion of standard cameras to enable them to capture images in the ultraviolet (UV) and infrared (IR) spectral regions has applications ranging from purely artistic to science and research. Taking the modification of the camera a step further and removing the color filter array (CFA) results in the formation of a monochrome camera. The spectral sensitivities of a range of cameras with different sensors which were converted to monochrome were measured and compared with standard multispectral camera conversions, with an emphasis on their behavior from the UV through to the IR regions.

Protective effects of galangin against H2O2/UVB-induced dermal fibroblast collagen degradation via hsa-microRNA-4535-mediated TGFβ/Smad signaling

This study aimed to investigate the mechanism underlying the protective effects of galangin against H₂O₂/UVB-induced damage using in vitro and in vivo models of photodamage. Moreover, we identified the involvement of miRNA regulation in this process. The H₂O₂/UVB-treated HS68 human dermal fibroblasts and UVB-induced C57BL/6J nude mice were used as in vitro and in vivo models of photodamage. The results showed that galangin treatment alleviated H₂O₂/UVB-induced reduction in cell viability, TGFβ/Smad signaling impairment, and dermal aging. Based on the results of microRNA array analyses and database searches, hsa-miR-4535 was identified as a potential candidate miRNA that targets Smad4. In vitro, galangin treatment activated Smad2/3/4 complex and inhibited hsa-miR-4535 expression in H2O2/UVB-exposed cells. In vivo, topical application of low (12 mg/kg) and high doses (24 mg/kg) of galangin to the dorsal skin of C57BL/6J nude mice significantly alleviated UVB-induced skin photodamage by promoting TGFβ/Smad collagen synthesis signaling, reducing epidermal hyperplasia, wrinkle formation, and skin senescence, as well as inhibiting hsa-miR-4535 expression. Taken together, our findings indicate a link between hsa-miR-4535 and TGFβ/Smad collagen synthesis signaling and suggest these factors to be involved in the photo-protective mechanism of galangin in dermal fibroblasts against H₂O₂/UVB-induced aging. The evidence indicated that galangin with anti-aging properties can be considered as a supplement in skin care products.

Antioxidant Bioactivity of Extracts from Beach Cast Leaves of Posidonia oceanica (L.) Delile

The marine environment is a generous source of biologically active compounds useful for human health. In 50 years, about 25,000 bioactive marine compounds have been identified, with an increase of 5% per year. Peculiar feature of algae and plants is the production of secondary metabolites, such as polyphenols, synthesized as a form of adaptation to environmental stress. Posidonia oceanica is a Mediterranean endemic and dominant seagrass and represents a biologically, ecologically and geologically important marine ecosystem. Within this study, methanolic and ethanolic extracts were generated from fresh and dried Posidonia oceanica leaves, with the aim to employ and valorize the beach cast leaves. The best yield and antioxidant activity (polyphenols content equal to 19.712 ± 0.496 mg GAE/g and DPPH IC50 of 0.090 µg/µL.) were recorded in 70% ethanol extracts (Gd-E4) obtained from leaves dried for two days at 60 °C and ground four times. HPLC analyses revealed the presence of polyphenols compounds (the most abundant of which was chicoric acid) with antioxidant and beneficial properties. Bioactive properties of the Gd-E4 extracts were evaluated in vitro using fibroblast cells line (HS-68), subjected to UV induced oxidative stress. Pre-treatment of cells with Gd-E4 extracts led to significant protection against oxidative stress and mortality associated with UV exposure, thus highlighting the beneficial properties of antioxidants compounds produced by these marine plants against photo damage, free radicals and associated negative cellular effects. Beach cast leaves selection, processing and extraction procedures, and the in vitro assay results suggested the potentiality of a sustainable approach for the biotechnological exploitation of this resource and could serve a model for other marine resources.

Citrulluside H and citrulluside T from young watermelon fruit attenuate ultraviolet B radiation-induced matrix metalloproteinase expression through the scavenging of generated reactive oxygen species in human dermal fibroblasts

BACKGROUND

Prolonged exposure to UV radiation disrupts the oxidative stress defense systems; in the absence of adequate reactive oxygen species (ROS)-scavenging mechanisms, the ROS produced cause oxidative damage to DNA, proteins, carbohydrates, and lipids. Thus, ROS elimination can protect against photoaging and possibly skin cancer. We recently isolated two novel phenolic glycosides (citrulluside H and citrulluside T) with antioxidative activity from young watermelon (Citrullus lanatus) fruits. In the present study, we evaluated the protective effect of these compounds against UV-B-induced photodamage in normal human dermal fibroblasts (NHDFs).

METHODS

NHDFs were exposed to UV-B irradiation at 25 mJ/cm² . Matrix metalloproteinase (MMP)-1 and MMP-3 mRNA levels were measured by quantitative real-time PCR. MMP protein expression, as well as MAPK and NF-κB signaling, was investigated by Western blot analysis. Activation protein-1 (AP-1) transcriptional activity was determined using a luciferase reporter assay. Intracellular ROS levels were measured using the CellROX™ Deep Red Reagent.

RESULTS

Citrulluside H and citrulluside T significantly downregulated the protein and mRNA expression of MMP-1 and MMP-3, which are associated with the onset of skin wrinkle formation. Importantly, inhibition of UV-B-induced MMP expression in NHDFs by citrulluside H and citrulluside T was primarily due to the attenuation of MAPK/AP-1 and NF-κB signaling via scavenging of the generated ROS.

CONCLUSION

Our findings delineated both citrulluside H and citrulluside T as potential agents for alleviating UV-induced skin photoaging.

Comparison of Single and Combined Use of Ergothioneine, Ferulic Acid, and Glutathione as Antioxidants for the Prevention of Ultraviolet B Radiation-Induced Photoaging Damage in Human Skin Fibroblasts

Ultraviolet B (UVB) irradiation can cause human skin damage or skin aging and wrinkle formation through photochemical reactions. Antioxidative substances may ameliorate UV damage. In this study, the anti-photoaging activity of three antioxidants—ergothioneine, ferulic acid, and glutathione—was investigated after UVB irradiation of Hs68 human skin fibroblast cells. The cells treated with these three antioxidants appeared similar to unirradiated control cells. UVB irradiation decreased cell viability by 26% compared to that of unirradiated control cells. However, the addition of either single or combined antioxidants enhanced cell viability after UVB irradiation. These three antioxidants can inhibit the production of reactive oxygen species (ROS) induced by the UVB irradiation of the Hs68 cells. Ergothioneine showed a greater inhibitory effect on matrix metalloproteinase-1 (MMP-1) performance than the other two antioxidants. IL-1 alpha was not detected in the Hs68 cells after exposure to a radiation dose of 150 mJ/cm2. Ergothioneine showed better restoration of type 1 procollagen than either ferulic acid or glutathione. Based on these results, the addition of two antioxidants was expected to restore type Ι procollagen production. In summary, these results demonstrate that the three tested antioxidants protect the skin against UVB-induced damage. The single and combined use of ergothioneine, ferulic acid, and glutathione has the potential for development as anti-photoaging materials in cosmetic applications.

Ursodeoxycholic Acid May Inhibit Environmental Aging-Associated Hyperpigmentation

Extrinsic aging of the skin caused by ultraviolet (UV) light or particulate matter is often manifested by hyperpigmentation due to increased melanogenesis in senescent skin. Ursodeoxycholic acid (UDCA), which has been commonly used as a health remedy for liver diseases, is known to possess antioxidant properties. This study was done to investigate whether UDCA inhibits cellular aging processes in the cells constituting human skin and it reduces melanin synthesis. ROS, intracellular signals, IL-1α, IL-8, TNF-α, cyclooxygenase (COX)-2, type I collagen, and matrix metalloproteinases (MMPs) levels were measured in human dermal fibroblasts treated with or without UDCA after UV exposure. Melanin levels and mechanistic pathways for melanogenesis were investigated. UDCA decreased ROS, senescence-associated secretory phenotype (SASP), and proinflammatory cytokines induced by UV treatment. UDCA reduced melanogenesis in normal human melanocytes cocultured with skin constituent cells. Our results suggest that UDCA could be a comprehensive agent for the treatment of environmental aging-associated hyperpigmentation disorders.

Reversal of heavy metal-induced antibiotic resistance by dandelion root extracts and taraxasterol

Introduction. Metal exposure is an important factor for inducing antibiotic resistance in bacteria. Dandelion extracts have been used for centuries in traditional Chinese and Native American medicine.

Aim. We assessed the effects of dandelion water extracts and taraxasterol on heavy metal-induced antibiotic resistance in Escherichia coli as well as the underlying mechanisms.

Methodology. Dandelion extracts were obtained through 4 h of boiling in distilled water. Bacterial growth was monitored with a spectrophotometer. Biochemical assays were performed to assess the activities and gene transcriptions of β-lactamase and acetyltransferase. Oxidative stress was determined using an oxidation-sensitive probe, H2DCFDA.

Results. The present study demonstrated that higher concentrations of nickel (>5 µg ml−1), cadmium (>0.1 µg ml−1), arsenic (>0.1 µg ml−1) and copper (>5 µg ml−1) significantly inhibited the growth of E. coli . Lower concentrations of nickel (0.5 µg ml−1), cadmium (0.05 µg ml−1) and arsenic (0.05 µg ml−1) had no effect on bacterial growth, but helped the bacteria become resistant to two antibiotics, kanamycin and ampicillin. The addition of dandelion root extracts and taraxasterol significantly reversed the antibiotic resistance induced by these heavy metals. The supplements of antibiotics and cadmium generated synergistic effects on the activities of β-lactamase and acetyltransferase (two antibiotic resistance-related proteins), which were significantly blocked by either dandelion root extract or taraxasterol. In contrast, oxidative stress was not involved in the preventative roles of dandelion root extracts and taraxasterol in heavy metal-induced antibiotic resistance.

Conclusion. This study suggests that heavy metals induce bacterial antibiotic resistance and dandelion root extracts and taraxasterol could be used to help reverse bacterial resistance to antibiotics.

Theophylline exerts complex anti-ageing and anti-cytotoxicity effects in human skin ex vivo

OBJECTIVE

Theophylline is a phosphodiesterase inhibitor that is being used clinically for asthma therapy. In addition, it is recognized as a cosmetic agent with possible anti-ageing and anti-oxidative properties. Nevertheless, how it affects human skin is still poorly examined.

METHODS

Theophylline (10 or 100 µM) was administered to the culture medium of full-thickness human skin ex vivo for 24 or 72 h.

RESULTS

Theophylline stimulated protein expression of the anti-oxidant metallothionein-1 and mRNA levels of collagen I and III. Assessment of fibrillin-1 immunohistology revealed enhanced structural stability of dermal microfibrils. Theophylline also exerted extracellular matrix-protective effects by decreasing MMP-2 and MMP-9 mRNA levels, partially antagonizing the effects of menadione, the potent, toxic ROS donor. In addition, it decreased menadione-stimulated epidermal keratinocytes apoptosis. Interestingly, theophylline also increased the level of intracutaneously produced melatonin, that is the most potent ROS-protective and DNA damage repair neuromediator, and tendentially increased protein expression of MT1, the melatonin receptor. Theophylline also increased the expression of keratin 15, the stem cell marker, in the epidermal basal layer but did not change mitochondrial activity or epidermal pigmentation.

CONCLUSION

This ex vivo pilot study in human skin shows that theophylline possesses several interesting complex skin-protective properties. It encourages further examination of theophylline as a topical candidate for anti-ageing treatment.

Anti-Photoaging Effect of Korean Mint (Agastache rugosa Kuntze) Extract on UVB-Irradiated Human Dermal Fibroblasts

Ultraviolet B (UVB) irradiation-induced photoaging leads to wrinkles, dryness, and skin roughness. UVB irradiation activates the production of reactive oxygen species (ROS) and stimulates the mitogen-activated protein kinase (MAPK)/activator protein-1 (AP-1) signaling pathway, which promotes expression of matrix metalloproteinases (MMPs) and inflammatory cytokines. The current study aimed to assess the anti-photoaging activity of Agastache rugosa extract (ARE) on UVB-treated human dermal fibroblasts. ARE treatment reduced the overproduction of ROS and promoted mRNA expression of anti-oxidant enzymes. ARE treatment significantly inactivated the MAPK/AP-1 signaling pathway, which downregulated the expression of MMPs. Moreover, ARE promoted the production of type-I procollagen and upregulated mRNA expression of collagen genes. Additionally, ARE suppressed the expression of inflammatory cytokines, including interleukin (IL)-1β, IL-6, and IL-8, by preventing expression of nuclear factor-kappa B. Collectively, our findings show that ARE could be a potential candidate for anti-photoaging treatment.

Induction of cystathionine gamma-lyase expression and metallothionein-1 S-sulfhydration alleviate cadmium-induced cell death in myoblast cells

Hydrogen sulfide (H₂S), a multifunctional gasotransmitter, participates in a wide range of cellular signal transduction and pathophysiological processes. Cystathionine gamma-lyase (CSE) acts as a major H₂S-generating enzyme in peripheral organs and tissues. As a cysteine-rich and heavy metal-binding protein, metallothionein-1 (MT-1) is known to protect cells from various environmental stresses. Here we demonstrated that exposure of cadmium (Cd) induced oxidative stress, depleted intracellular thiols, and stimulated apoptotic cell death in mouse myoblast cells. CSE expression and H₂S production were significantly enhanced by Cd treatment. NaHS, a well-known H₂S donor, at physiologically relevant concentration significantly alleviated Cd-induced damage in both myoblasts and mouse skeletal muscles. In contrast, down-regulation of CSE/H₂S system deteriorated Cd-stimulated oxidative stress and cell death. Exposure of the cells to Cd lead to increased expressions of metal regulatory transcription factor 1 and MT-1, while siRNA-mediated MT-1 knockdown alleviated Cd-induced CSE expression and caused more oxidative stress and cell death. In addition, H₂S post-translationally modified MT-1 by S-sulfhydration and stabilized zinc-protein complex. Taken together, these data suggest that CSE/H₂S system would protect myoblasts and skeletal muscles from Cd-induced damage by S-sufhydrating MT-1.

H2S Protects against Cardiac Cell Hypertrophy through Regulation of Selenoproteins

Cardiac hypertrophy is defined as the enlargement of the cardiac myocytes, leading to improper nourishment and oxygen supply due to the increased functional demand. This increased stress on the cardiac system commonly leads to myocardial infarction, contributing to 85% of all cardiac-related deaths. Cystathionine gamma-lyase- (CSE-) derived H₂S is a novel gasotransmitter and plays a critical role in the preservation of cardiac functions. Selenocysteine lyase (SCLY) has been identified to produce H₂Se, the selenium homologue of H₂S. Deficiency of selenium is often found in Keshan disease, a congestive cardiomyopathy. The interaction of H₂S and H₂Se in cardiac cell hypertrophy has not been explored. In this study, cell viability was evaluated with a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Oxidative stress and cell size were observed through immunostaining. The expression of genes was determined by real-time PCR and western blot. Here, we demonstrated that incubation of rat cardiac cells (H9C2) with H₂O₂ lead to increased oxidative stress and cell surface area, which were significantly attenuated by pretreatment of either H₂S or H₂Se. H₂S incubation induced SCLY/H₂Se signaling, which next caused higher expressions and activities of selenoproteins, including glutathione peroxidase and thioredoxin reductase. Furthermore, deficiency of CSE inhibited the expressions of SCLY and selenoprotein P in mouse heart tissues. We also found that both H₂S and H₂Se stimulated Nrf2-targeted downstream genes. These data suggests that H₂S protects against cardiac hypertrophy through enhancement of a group of antioxidant proteins.

Asperyellone prevents HDF cells from UVB irradiation damages: An elaborated study

The current study explores the photo-protective effect of asperyellone (AY) (a fungal secondary metabolite), assessed under in vitro condition using human dermal fibroblast cell line. AY was isolated from Aspergillus sp. during the resting phase and purified. The initial cytocompatibility assessment on concentrations of AY and the duration of exposure of UVB irradiations were studied respectively. N-acetyl-L-cysteine (NAC) was used as positive control. Cells were then pretreated with optimized concentration of AY (2.0 μM) and NAC (1 mM) for 1 hour and then UVB irradiated (30 mJ/cm ² ) for the period of 10 minutes. Results revealed that reactive oxygen species generated upon UVB irradiation found scavenged by the AY pretreatment at a significant level. Furthermore, an appreciable reduction in apoptotic cell count and DNA damages support the scavenging effect of AY. Assessments on the expression of enzymatic and nonenzymatic antioxidants evidently prove the protective role of AY. The reduced expression levels of inflammatory markers (TNF-α and COX-2), collagen degraders (MMP 2 and MMP 9), apoptotic protein expressions (Bax and Bcl-2), and cell-cycle arrest analyses substantiate the photo-protective effect of AY similar to NAC (positive control). Thus, the observations made in the current study indicate the possible role of AY as a photo-protective agent.

[Protective action of fish muscle extracts against cellular senescence induced by oxidative stress]

Muscle extracts of some fish species, i.e. pike (Esox lucius), sterlet (Acipenser ruthenus), pink salmon (Oncorhynchus gorbuscha) and, to a lesser extent, perch (Perca fluviatilis) and Russian sturgeon, (Acipenser gueldenstaedtii) prevent the development of premature senescence of the human embryonic fibroblasts induced by the sublethal concentration of H2O2. Muscle extracts of other fish species tested, i.e. coho salmon (Oncorhynchus kisutch) and zander (Sander lucioperca), have not demonstrated this feature. Cell proliferation increased after the action of the senescence-inhibiting muscle extracts. Possible mechanisms of the action of nature biologically active compounds that interfere with the development of stress-induced cell senescence are discussed.

Dihydrocaffeic Acid Prevents UVB-Induced Oxidative Stress Leading to the Inhibition of Apoptosis and MMP-1 Expression via p38 Signaling Pathway

Chronic UVB exposure promotes oxidative stress, directly causes molecular damage, and induces aging-related signal transduction, leading to skin photoaging. Dihydrocaffeic acid (DHCA) is a phenolic compound with potential antioxidant capacity and is thus a promising compound for the prevention of UVB-induced skin photodamage. The aim of this study was to evaluate the antioxidant and protective effect of DHCA against oxidative stress, apoptosis, and matrix metalloproteinase (MMP) expression via the mitogen-activated protein kinase (MAPK) signaling pathway on L929 fibroblasts irradiated with UVB. DHCA exhibited high antioxidant capacity on 2,2-diphenyl-1-picrylhydrazyl (DPPH^•), 2,2-azinobis-3-ethylbenzothiazoline-6-sulphonic acid (ABTS^•+), and xanthine/luminol/xanthine oxidase (XOD) assays and reduced UVB-induced cell death in the neutral red assay. DHCA also modulated oxidative stress by decreasing intracellular reactive oxygen species (ROS) and extracellular hydrogen peroxide (H₂O₂) production, enhancing catalase (CAT) and superoxide dismutase (SOD) activities and reduced glutathione (GSH) levels. Hence, cellular damage was attenuated by DHCA, including lipid peroxidation, apoptosis/necrosis and its markers (loss of mitochondria membrane potential, DNA condensation, and cleaved caspase 9 expression), and MMP-1 expression. Furthermore, DHCA reduced the phosphorylation of MAPK p38. These findings suggest that DHCA can be used in the development of skin care products to prevent UVB-induced skin damage.

Reversal of Sp1 transactivation and TGFβ1/SMAD1 signaling by H2S prevent nickel-induced fibroblast activation

Nickel as a heavy metal is known to bring threat to human health, and nickel exposure is associated with changes in fibroblast activation which may contribute to its fibrotic properties. H₂S has recently emerged as an important gasotransmitter involved in numerous cellular signal transduction and pathophysiological responses. Interaction of nickel and H₂S on fibroblast cell activation has not been studied so far. Here, we showed that a lower dose of nickel (200 μM) induced the activation of human fibroblast cells, as evidenced by increased cell growth, migration and higher expressions of α-smooth muscle actin (αSMA) and fibronectin, while high dose of nickel (1 mM) inhibited cell viability. Nickel reduced intracellular thiol contents and stimulated oxidative stress. Nickel also repressed the mRNA and protein expression of cystathionine gamma-lyase (CSE, a H₂S-generating gene) and blocked the endogenous production of H₂S. Exogenously applied NaHS (a H₂S donor) had no effect on nickel-induced cell viability but significantly attenuated nickel-stimulated cell migration and the expression of αSMA and fibronectin. In contrast, CSE deficiency worsened nickel-induced αSMA expression. Moreover, H₂S incubation reversed nickel-stimulated TGFβ1/SMAD1 signal and blocked TGFβ1-initiated expressions of αSMA and fibronectin. Nickel inhibited the interaction of Sp1 with CSE promoter but strengthened the binding of Sp1 with TGFβ1 promoter, which was reversed by exogenously applied NaHS. These data reveal that H₂S protects from nickel-stimulated fibroblast activation and CSE/H₂S system can be a potential target for the treatment of tissue fibrosis induced by nickel.

Fluorofenidone inhibits UV-A induced senescence in human dermal fibroblasts via the mammalian target of rapamycin-dependent SIRT1 pathway

The aim of this study was to investigate the protective effect of fluorofenidone (5‐methyl‐1‐[3‐fluorophenyl]‐2‐[1H]‐pyridone, AKF‐PD) on ultraviolet (UV)‐A‐induced senescence in human dermal fibroblasts (HDF) and examine the mechanisms involved. HDF were treated with AKF‐PD. Senescence‐associated (SA)‐β‐galactosidase level, cell viability and expression of p16 were evaluated. In addition, UV‐A‐irradiated HDF were treated with AKF‐PD, rapamycin and MHY1485; SA‐β‐galactosidase staining, 3‐(4 5‐dimethylthiazol‐2‐yl)‐2 5‐diphenyltetrazolium bromide assay and western blot for SIRT1 were performed; and phosphorylated mammalian target of rapamycin (p‐mTOR) expression and reactive oxygen species (ROS) levels were measured. Intracellular ROS was detected by the 2′,7′‐dichlorofluroescein diacetate probe. Our results showed that AKF‐PD substantially attenuated the changes of p16 expression, SA‐β‐galactosidase staining and cellular proliferation induced by UV‐A irradiation in HDF. AKF‐PD rescued the increased mTOR phosphorylation and reduced SIRT1 expression induced by UV‐A irradiation in HDF. AKF‐PD and rapamycin together had a synergistic effect on p‐mTOR reduction and SIRT1 increase. mTOR activator MHY1485 partly blocked the above effects. Moreover, intracellular ROS level induced by UV‐A irradiation could partly decrease by AKF‐PD, and MHY1485 could reduce this effect. Our results indicated that AKF‐PD could alleviate HDF senescence induced by UV‐A‐irradiation by inhibiting the p‐mTOR and increasing SIRT1. Moreover, AKF‐PD may be a potential treatment material for skin.

Galangin suppresses H2 O2 -induced aging in human dermal fibroblasts

Human skin aging is a progressive process that includes intrinsic aging and extrinsic photodamage, both of which can cause an accumulation of reactive oxygen species (ROS), resulting in dermal fibrosis dysfunction and wrinkle formation. Galangin is a flavonoid that exhibits anti-inflammatory and antioxidative potential. Previous studies have reported that galangin has antioxidative activity against ROS-mediated stress. The aim of the present study is to determine the antiaging effects of galangin on dermal fibroblasts exposed to H₂ O₂ . In this study, we established a hydrogen peroxide-induced inflammation and aging model using human HS68 dermal fibroblasts. Stimulation of fibroblasts with H₂ O₂ is associated with skin aging and increased expression of inflammation-related proteins, along with downregulation of collagen I/III formation and expression of antioxidative proteins. Galangin effectively reduced NF-κB activation, the expression of inflammation-related proteins and cell aging. Galangin also reversed H₂ O₂ -activated cell senescence in HS68 cells. Our results reveal that galangin protects human dermal fibroblasts by inhibiting NF-κB activation, decreases the expression of inflammatory factors and upregulates IGF1R/Akt-related proteins, indicating that galangin may be a potential candidate for developing natural antiaging products that protect skin from damage caused by ROS.

Inositol Derivatives and Phenolic Compounds from the Roots of Taraxacum coreanum

In this study, the characterization of chemical constituents and biological activity of the roots of Taraxacum coreanum (Asteraceae) was attempted. Phytochemical investigation of the roots of T. coreanum led to the isolation of two new inositol derivatives, taraxinositols A (1) and B (2), and a new phenolic compound, taraxinol (16), together with twenty known compounds including four inositol derivatives, neo-inositol-1,4-bis (4-hydroxybenzeneacetate) (3), chiro-inositol-1,5-bis(4- hydroxybenzeneacetate) (4), chiro-inositol-2,3-bis (4-hydroxybenzeneacetate) (5) and chiro-inositol- 1,2,3-tris (4-hydroxybenzeneacetate) (6), nine phenolic compounds: p-hydroxybenzaldehyde (7), vanillin (8), syringaldehyde (9), vanillic acid (10), 4-methoxyphenylacetic acid (11), 4-hydroxy- phenylacetic acid methyl ester (12), optivanin (13), isoferulic acid (14) and dihydroconiferyl alcohol (15), four coumarins: nodakenetin (17), decursinol (18), prangol (19) and isobyakangelicin (20), and three lignans: syringaresinol-4′-O-β-d-glucoside (21), syringaresinol (22), and pinoresinol (23). The structures of isolated compounds were determined on the basis of spectroscopic analysis. Among the isolated compounds, vanillic acid, isoferulic acid and syringaresinol showed radical scavenging activity with IC₅₀ values ranging from 30.4 to 75.2 μM.

Lycium barbarum Polysaccharides Protect Rat Corneal Epithelial Cells against Ultraviolet B-Induced Apoptosis by Attenuating the Mitochondrial Pathway and Inhibiting JNK Phosphorylation

Lycium barbarum polysaccharides (LBPs) have been shown to play a key role in protecting the eyes by reducing the apoptosis induced by certain types of damage. However, it is not known whether LBPs can protect damaged corneal cells from apoptosis. Moreover, no reports have focused on the role of LBPs in guarding against ultraviolet B- (UVB-) induced apoptosis. The present study aimed to investigate the protective effect and underlying mechanism of LBPs against UVB-induced apoptosis in rat corneal epithelial (RCE) cells. The results showed that LBPs significantly prevented the loss of cell viability and inhibited cell apoptosis induced by UVB in RCE cells. LBPs also inhibited UVB-induced loss of mitochondrial membrane potential, downregulation of Bcl-2, and upregulation of Bax and caspase-3. Finally, LBPs attenuated the phosphorylation of c-Jun NH₂-terminal kinase (JNK) triggered by UVB. In summary, LBPs protect RCE cells against UVB-induced damage and apoptosis, and the underlying mechanism involves the attenuation of the mitochondrial apoptosis pathway and the inhibition of JNK phosphorylation.

Apigenin prevents ultraviolet-B radiation induced cyclobutane pyrimidine dimers formation in human dermal fibroblasts

Exposure to solar ultraviolet-B (UVB) radiation leads to the formation of cyclobutane pyrimidine dimers (CPDs). We investigated the protective effect of apigenin against UVB-induced CPDs formation in human dermal fibroblasts cells (HDFa). For this purpose, HDFa cells were treated with apigenin (15μM) prior to UVB irradiation (20mJ/cm²); DNA damage and subsequent molecular end points were observed. Exposure to UVB radiation increased significant CPDs formation in HDFa cells and the frequencies of CPDs were reduced by treatment with apigenin (15μM). UVB-induced CPDs downregulates the expression of nucleotide excision repair (NER) genes such as xeroderma pigmentosum complementation group C, B, G and F (XPC, XPB, XPG and XPF), transcription factor II human (TFIIH) and excision repair cross-complementation group 1 (ERCC1) in HDFa cells. Conversely, apigenin treatment restored UVB-induced loss of NER proteins in HDFa cells, which indicates its preventive effect against CPDs formation. Besides, single low dose UVB-exposure induced nuclear fragmentation, apoptotic frequency and apoptotic proteins expression (Bax and Caspase-3) have been prevented by the apigenin pretreatment. Furthermore, apigenin exhibits strong UV absorbance property and showed 10.08 SPF value. Thus, apigenin can protect skin cells against UVB-induced CPDs formation probably through its sunscreen effect. Hence, apigenin can be considered as an effective protective agent against UV induced skin damages.

Impact on Autophagy and Ultraviolet B Induced Responses of Treatment with the MTOR Inhibitors Rapamycin, Everolimus, Torin 1, and pp242 in Human Keratinocytes

The mechanistic target of Rapamycin (MTOR) protein is a crucial signaling regulator in mammalian cells that is extensively involved in cellular biology. The function of MTOR signaling in keratinocytes remains unclear. In this study, we detected the MTOR signaling and autophagy response in the human keratinocyte cell line HaCaT and human epidermal keratinocytes treated with MTOR inhibitors. Moreover, we detected the impact of MTOR inhibitors on keratinocytes exposed to the common carcinogenic stressors ultraviolet B (UVB) and UVA radiation. As a result, keratinocytes were sensitive to the MTOR inhibitors Rapamycin, everolimus, Torin 1, and pp242, but the regulation of MTOR downstream signaling was distinct. Next, autophagy induction only was observed in HaCaT cells treated with Rapamycin. Furthermore, we found that MTOR signaling was insensitive to UVB but sensitive to UVA radiation. UVB treatment also had no impact on the inhibition of MTOR signaling by MTOR inhibitors. Finally, MTOR inhibition by Rapamycin, everolimus, or pp242 did not affect the series of biological events in keratinocytes exposed to UVB, including the downregulation of BiP and PERK, activation of Histone H2A and JNK, and cleavage of caspase-3 and PARP. Our study demonstrated that MTOR inhibition in keratinocytes cannot always induce autophagy, and the MTOR pathway does not play a central role in the UVB triggered cellular response.

Wound Healing Activity of Extracts and Formulations of Aloe vera, Henna, Adiantum capillus-veneris, and Myrrh on Mouse Dermal Fibroblast Cells

Background:

Among the most important factors in wound healing pathways are transforming growth factor beta1 and vascular endothelial growth factor. Fibroblasts are the main cell in all phases wound closure. In this study, the extracts of plant materials such as Adiantum capillus-veneris, Commiphora molmol, Aloe vera, and henna and one mixture of them were used to treatment of normal mouse skin fibroblasts.

Methods:

Cytotoxic effects of each extract and their mixture were assessed on mouse skin fibroblasts cells using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. We performed migration assays to assess migration properties of mouse skin fibroblasts cells in response to the extracts. Changes in the gene expression of the Tgfβ1 and Vegf-A genes were monitored by real-time polymerase chain reaction.

Results:

A. capillus-veneris, C. molmol and henna extract improved the expression of Tgfβ1 gene. All used extracts upregulated the expression of Vegf-A gene and promoted the migration of mouse fibroblast cells in vitro.

Conclusions:

The present study demonstrated that the mentioned herbal extracts might be effective in wound healing, through the improvement in the migration of fibroblast cells and regulating the gene expression of Tgfβ1 and Vegf-A genes in fibroblast cells treated with extracts.

Pretreatment of Ferulic Acid Protects Human Dermal Fibroblasts against Ultraviolet A Irradiation

Background

Approximately 90%~99% of ultraviolet A (UVA) ray reaches the Earth's surface. The deeply penetrating UVA rays induce the formation of reactive oxygen species (ROS), which results in oxidative stress such as photoproducts, senescence, and cell death. Thus, UVA is considered a primary factor that promotes skin aging.

Objective

Researchers investigated whether pretreatment with ferulic acid protects human dermal fibroblasts (HDFs) against UVA-induced cell damages.

Methods

HDF proliferation was analyzed using the water-soluble tetrazolium salt assay. Cell cycle distribution and intracellular ROS levels were assessed by flow cytometric analysis. Senescence was evaluated using a senescence-associated β-galactosidase assay, while Gadd45α promoter activity was analyzed through a luciferase assay. The expression levels of superoxide dismutase 1 (SOD1), catalase (CAT), xeroderma pigmentosum complementation group A and C, matrix metalloproteinase 1 and 3, as well as p21 and p16 were measured using quantitative real-time polymerase chain reaction.

Results

Inhibition of proliferation and cell cycle arrest were detected in cells that were irradiated with UVA only. Pretreatment with ferulic acid significantly increased the proliferation and cell cycle progression in HDFs. Moreover, ferulic acid pretreatment produced antioxidant effects such as reduced DCF intensity, and affected SOD1 and CAT mRNA expression. These effects were also demonstrated in the analysis of cell senescence, promoter activity, expression of senescent markers, and DNA repair.

Conclusion

These results demonstrate that ferulic acid exerts protective effects on UVA-induced cell damages via anti-oxidant and stress-inducible cellular mechanisms in HDFs.

Herbal extracts, lichens and biomolecules as natural photo-protection alternatives to synthetic UV filters. A systematic review

Besides the unquestionable positive effects of solar exposure for human health, UV rays have been widely investigated for toxicology aspects related to excessive UVB and UVA doses, which involve sunburns, skin aging, DNA skin damage and tumorigenesis. At present, synthetic and mineral sunscreens are used to protect against these damages but several natural molecules can provide UV protection, including also synergic effect or enhanced photo stability. Although a large number of herbal extracts and plant origin molecules can deserve potential applications, most of the study reported utilizes different method and different strategies of investigation, making thus difficult to understand the real versus claimed potential. This is possibly one of the reasons why, beside the large body of literature there are no officially approved natural commercial sun-filter but a consistent number of commercially available solar products (sunscreen) on the market that contain herbal derivatives. In this review we have evaluated the papers appeared in the last 15years and we have critically collected the most significant data. Several databases, namely Scifinder, Pubmed, Google Scholar, ISI-Web of Science and Scopus, were used as literature sources; excluding patents and symposium or congress papers. Only articles in the English language have been selected. New formulation, new skin delivery systems, skin penetration enhancers and boosters are most likely the next frontier of investigation in order to better understand the role of whole herbal extracts in exerting their photo protective activity.