Seabuckthorn pulp extract alleviates UV-B-induced skin photo-damage by significantly reducing oxidative stress-mediated endoplasmic reticulum stress and DNA Damage in human primary skin fibroblasts and Balb/c mice skin.

Skin homeostasis is predominantly compromised by exposure to UV-B irradiation, leading to several physiopathological processes at cellular and tissue levels that deteriorate skin function and integrity. The current study investigated the photo-protective role of seabuckthorn fruit pulp (SBT) extract against UV-B-induced damage in primary human skin fibroblasts (HDFs) and Balb/C mice skin. We subjected HDFs and Balb/C mice to UV-B irradiation and measured multiple cellular damage indicators. We found that UV-B-irradiated HDFs treated with SBT had a considerably greater survival rate than cells exposed to UV-B radiation alone. The UV-B irradiation-induced ROS generation led to the degradation of the extracellular matrix, inflammation, DNA damage, endoplasmic reticulum (ER) stress, and apoptosis. SBT treatment significantly reduced these manifestations. Topical application of SBT alleviated UV-B-induced epidermal thickening, leukocyte infiltration, and degradation of extracellular matrix in Balb/c mice skin. Based on our results, we conclude that SBT has the potential to be developed as a therapeutic/cosmetic remedy for the prevention of skin photo-damage.

Naringenin, a flavanone constituent from Sea buckthorn pulp extract, prevents ultraviolet (UV)-B radiation-induced skin damage via alleviation of impaired mitochondrial dynamics mediated inflammation in human dermal fibroblasts and Balb/c mice models.

Ultraviolet-B (UV-B) irradiation has been reported to cause oxidative stress and inflammation-mediated skin photo-damage. Furthermore, mitochondrial dynamics have been implicated to play a critical role in these processes. For the first time, we describe in this study how UVB-induced aberrant mitochondrial dynamics and inflammation interact in primary human dermal fibroblasts (HDFs). Our findings demonstrated that UV-B irradiation induced -impairment in mitochondrial dynamics by increasing mitochondrial fragmentation in HDFs. Imbalanced mitochondrial dynamics lead to the activation of NFкB and pro-inflammatory cytokines. The current study further aimed to investigate the protective effect of Naringenin (a naturally occurring flavonoid isolated from Sea buckthorn fruit pulp) against UV-B-induced mitochondrial fragmentation and inflammation in HDFs and Balb/c mice. Although Naringenin has been shown to have anti-inflammatory and antioxidant potential, its effects and mechanisms of action on UVB-induced inflammation remained unclear. We observed that Naringenin restored the UV-B-induced imbalance in mitochondrial fission and fusion in HDFs. It also inhibited the phosphorylation of NFкB and reduced the generation of pro-inflammatory cytokines. Naringenin also alleviated UV-B-induced oxidative stress by scavenging the reactive oxygen species and up-regulating the cellular antioxidant enzymes (Catalase and Nrf2). Topical application of Naringenin to the dorsal skin of Balb/c mice exposed to UV-B radiation prevented mitochondrial fragmentation and progression of inflammatory responses. Naringenin treatment prevented neutrophil infiltration and epidermal thickening in mice's skin. These findings provide an understanding for further research into impaired mitochondrial dynamics as a therapeutic target for UV-B-induced inflammation. Our findings imply that Naringenin could be developed as a therapeutic remedy against UVB-induced inflammation.

Light Pollution and Oxidative Stress: Effects on Retina and Human Health.

Visible light refers to the frequencies within the electromagnetic spectrum that humans can see, encompassing radiation with wavelengths falling between 380 nm to 760 nm. The energy of a single photon increases with its frequency. In the retina, photoreceptor cells contain light-sensitive pigments that absorb light and convert it into electrical stimuli through a process known as phototransduction. However, since the absorption spectrum of photoreceptors closely aligns with blue light (ranging from 400 to 500 nm), exposure to high light intensities or continuous illumination can result in oxidative stress within these cells, leading to a loss of their functionality. Apart from photoreceptor cells, the retina also houses photosensitive ganglion cells, known as intrinsically photosensitive retinal ganglion cells (ipRGCs). These cells relay information to the suprachiasmatic nucleus in the brain, playing a crucial role in modulating melatonin secretion, which in turn helps in synchronizing the body's circadian rhythms and responses to seasonal changes. Both, ipRGCs and skin possess a peak sensitivity to blue wavelengths, rendering them particularly susceptible to the effects of excessive blue light exposure. This study delves into the consequences of excessive illumination and/or prolonged exposure to blue light on retinal function and explores its implications for human health.

HHL1 and SOQ1 synergistically regulate nonphotochemical quenching in Arabidopsis.

Nonphotochemical quenching (NPQ) is an important photoprotective mechanism that quickly dissipates excess light energy as heat. NPQ can be induced in a few seconds to several hours; most studies of this process have focused on the rapid induction of NPQ. Recently, a new, slowly induced form of NPQ, called qH, was found during the discovery of the quenching inhibitor suppressor of quenching 1 (SOQ1). However, the specific mechanism of qH remains unclear. Here, we found that hypersensitive to high light 1 (HHL1)-a damage repair factor of photosystem II-interacts with SOQ1. The enhanced NPQ phenotype of the hhl1 mutant is similar to that of the soq1 mutant, which is not related to energy-dependent quenching or other known NPQ components. Furthermore, the hhl1 soq1 double mutant showed higher NPQ than the single mutants, but its pigment content and composition were similar to those of the wildtype. Overexpressing HHL1 decreased NPQ in hhl1 to below wildtype levels, whereas NPQ in hhl1 plants overexpressing SOQ1 was lower than that in hhl1 but higher than that in the wildtype. Moreover, we found that HHL1 promotes the SOQ1-mediated inhibition of plastidial lipoprotein through its von Willebrand factor type A domain. We propose that HHL1 and SOQ1 synergistically regulate NPQ.

Protection of Skin Fibroblasts from Infrared-A-Induced Photo-Damage Using Ginsenoside Rg3(S)-Incorporated Soybean Lecithin Liposomes.

Protection of skin cells from chronic infrared-A (IRA) irradiation is crucial for anti-photoaging of the skin. In this study, we investigated the protective activity of Rg3(S) and Rg3(S)-incorporated anionic soybean lecithin liposomes (Rg3/Lipo) with a size of approximately 150 nm against IRA-induced photodamage in human fibroblasts. The formulated Rg3/Lipo showed increased solubility in aqueous solution up to a concentration of 200 µg/ml, compared to free Rg3(S). In addition, Rg3/Lipo exhibited superior colloidal stability in aqueous solutions and biocompatibility for normal human dermal fibroblasts (NHDFs). After repeated IRA irradiation on NHDFs, elevated levels of cellular and mitochondrial reactive oxygen species (ROS) were greatly reduced by Rg3(S) and Rg3/Lipo. In addition, cells treated with Rg3/Lipo exhibited noticeably reduced apoptotic signals following IRA irradiation compared to untreated cells. Thus, considering aqueous solubility and cellular responses, Rg3/Lipo could serve as a promising infrared protector for healthy aging of skin cells.

High-light inhibition of two submerged macrophytes in a shallow water experiment.

The negative effects, caused by high light, on algae, terrestrial and marine aquatic plants are well documented; those negative effects on freshwater submerged plants are, however, not well known. We determined the negative effects of two common submerged species, Myriophyllum spicatum and Vallisneria natans, on their growth and reproduction in a shallow water experiment along an irradiance gradient. Our results highlighted that the plant mass, relative growth rate and shoot height of V. natans and M. spicatum, and root mass and root length:root mass of M. spicatum and leaf mass and shoot height:shoot mass of V. natans were significantly negatively affected in shallow water with high-light regime (>50 % of full light). While the ramet number of the two species was stimulated by from 20.0 to 36.4 %, and root length, root:shoot, chlorophyll (a:b), chlorophyll (a + b), leaf carbon, nitrogen and phosphorus contents of the two studied macrophytes were not significantly impacted by light. Our results indicated that the high-light inhibition of plant growth was greater on the shoots than on the roots of the plants, although these effects were significantly different between the two studied submerged species and among the measured traits. Accordingly, we should avoid negative effects caused by high light to improve the performance of submerged species when we conduct submerged aquatic vegetation restoration programmes in eutrophic lakes.

Curcumin protection against ultraviolet-induced photo-damage in Hacat cells by regulating nuclear factor erythroid 2-related factor 2.

Curcumin suppressed ultraviolet (UV) induced skin carcinogenesis and activated the nuclear factor erythroid 2-related factor 2 (Nrf2) pathway. However, whether curcumin protects skin injury caused by UV is still unknown. A vitro model was established and curcumin effects on Hacat cells were detected. Nrf2 was knocked down in Hacat cells to verify the Nrf2 role in the protective effect of curcumin. Results indicated that ultraviolet A (UVA) (or ultraviolet B (UVB)) irradiation would lead to decreased cell proliferation, increased cell apoptosis, decreased catalase, heme oxygenase 1, and superoxide dismutase expression, and increased levels of protein carbonylation and malondialdehyde (p < 0.05). These adverse events could be reversed by adding 5-µM curcumin. Meanwhile, we found that the application of curcumin effectively induced Nrf2 nuclear accumulation in Hacat cells. While in the Nrf2 knockdown cells, the protective effects of curcumin against UVA (or UVB) were attenuated. Conclusively, curcumin protects Hacat cells against UV exposure-induced photo-damage by regulating Nrf2 expression.

Efectos terapéuticos de la crioterapia con nitrógeno líquido en lesiones por fotodaño, en la consulta dermatológica / Therapeutic effects of cryotherapy with liquid nitrogen in lesions by photo damage in dermatologic consultation

RESUMEN La crioterapia es el conjunto de procedimientos que utilizan el frío en la terapéutica médica. Emplea diversos sistemas y tiene como resultado la disminución de la temperatura de la piel; produce una destrucción local de tejido de forma eficaz y controlada. El objetivo de este trabajo fue realizar una actualización para exponer los aspectos esenciales sobre formas de empleos, indicaciones, complicaciones y contraindicaciones. Existen varios métodos de aplicación de la crioterapia, que incluyen las técnicas de congelación de spray o aerosol y con aplicadores, el método criosonda, y el uso de termoacoplador. Está indicada en varias entidades, entre las que se encuentran la queratosis seborreica y actínica, lentigos solares, carcinoma basocelular y espinocelular in situ. Las complicaciones más observadas son vesicoampollas, hiperpigmentación e hipopigmentación, y las contraindicaciones comunes son intolerancia al frío, tumores con bordes no delimitados o con pigmentación muy oscura, en localizaciones cerca de los márgenes de los ojos, párpados, mucosas, alas nasales y el conducto auditivo. El dominio de los métodos de aplicación e indicaciones es indispensable para elegir la conducta adecuada; de esta forma se evitan complicaciones y efectos colaterales (AU).

ABSTRACT Cryotherapy is the whole of procedures that use cold in medical therapy. It uses various systems and results in a decrease in skin temperature, leading to a local destruction of tissue in an effective and controlled way. The objective of this work is to make an update to expose the essential aspects on the ways of use, indications, complications and contraindications. There are several cryotherapy application methods that include spray or spray freezing techniques and applicators, the cryoprobe method, and the thermocoupler use. It is indicated in several entities, and among the most frequent are seborrheic and actinic keratosis, solar lentigo, basal cell and squamous cell carcinomas in situ. The most observed complications are vesical blisters, hyperpigmentation and hypopigmentation, and the most common complications are: cold intolerance, tumors with non-delimited borders or very dark pigmentation, located near the margins of the eyes, on eyelids, mucous membranes, nasal wings, and on the ear canal. The mastery of the signs and application methods are essential to choose the appropriate behavior against the disease: side effects and complications are avoided that way (AU).

Exosomal MiR-769-5p Exacerbates Ultraviolet-Induced Bystander Effect by Targeting TGFBR1.

Exosomal microRNAs have been investigated in bystander effect, but it is unclear whether microRNA works in ultraviolet radiation-induced bystander effects (UV-RIBEs) and what the underlying mechanism could be. Exosomes from ultraviolet (UV)-irradiated human skin fibroblasts (HSFs) were isolated and transferred to normal HSFs, followed by the detection of proliferation rate, oxidative damage level, and apoptosis rate. Exosomal miRNAs were evaluated and screened with miRNA sequencing and quantitative reverse transcriptase-polymerase chain reaction method. MiRNA shuttle and bystander photodamage reactions were observed after transfection of miR-769-5p. MiR-769-5p targeting gene transforming growth factor-ß1 (TGFBR1), and TGFBR1 mRNA 3'-untranslated region (UTR) was assessed and identified by Western blotting and dual-luciferase reporter assay. Bystander effects were induced after being treated with isolated exosomes from UV-irradiated HSFs. Exosomal miR-769-5p expression was significantly upregulated. Human skin fibroblasts showed lower proliferation, increasing oxidative damage, and faster occurrence of apoptosis after transfection. Exosome-mediated transfer of miR-769-5p was observed. Upregulation of miR-769-5p induced bystander effects, whereas downregulation of miR-769-5p can suppress UV-RIBEs. In addition, miR-769-5p was found to downregulate TGFBR1 gene expression by directly targeting its 3'-UTR. Our results demonstrate that exosome-mediated miR-769-5p transfer could function as an intercellular messenger and exacerbate UV-RIBEs. MiR-769-5p inhibits the expression of TGFBR1 by targeting TGFBR1 mRNA 3'-UTR.

Lactic Acid Bacteria and Lactic Acid for Skin Health and Melanogenesis Inhibition.

Lactic acid bacteria are beneficial to human health. Lactic acid bacteria have wide applications in food, cosmetic and medicine industries due to being Generally Recognized As Safe (GRAS) and a multitude of therapeutic and functional properties. Previous studies have reported the beneficial effects of lactic acid bacteria, their extracts or ferments on skin health, including improvements in skin conditions and the prevention of skin diseases. Lipoteichoic acid isolated from Lactobacillus plantarum was reported to inhibit melanogenesis in B16F10 melanoma cells. In particular, lipoteichoic acid also exerted anti-photoaging effects on human skin cells by regulating the expression of matrix metalloproteinase- 1. The oral administration of Lactobacillus delbrueckii and other lactic acid bacteria has been reported to inhibit the development of atopic diseases. Additionally, the clinical and histologic evidence indicates that the topical application of lactic acid is effective for depigmentation and improving the surface roughness and mild wrinkling of the skin caused by environmental photo-damage. This review discusses recent findings on the effects of lactic acid bacteria on skin health and their specific applications in skin-whitening cosmetics.

Structure of photo-damaged white and naturally pigmented human hair.

The effect of photo-degradation processes on the morphology and ultrastructure of pigmented and non-pigmented hair was evaluated in this work by small angle X-ray scattering (SAXS) and transmission electron microscopy (TEM). Samples consisted of three types of grey hair (separated out into subsamples of totally white and totally black strands) and one type of dark-brown hair exposed to solar irradiation for 75 h or to a mercury lamp for 600 h. SAXS patterns showed that irradiation mainly damaged the amorphous regions of hair, and in some types of hair, an ordered structure appeared, with spaces of ca. 4.5 nm. This structure occurred independently of the presence of pigments and its scattering intensity increased after irradiation. Layers of lipids present in the cuticle may be responsible for this scattering around 4.5 nm, as indicated by TEM images. TEM also showed morphological changes in the outermost cuticle layers, such as the degradation of endocuticle and the detachment of the cell membrane complex. Therefore, the results presented herewith showed that irradiation caused different damages to the hair amorphous fractions, especially in the cuticle layers, which are the most exposed areas of the hair strands.

Label-free surface-enhanced Raman spectroscopy with artificial neural network technique for recognition photoinduced DNA damage.

Taking advantage of surface-enhanced Raman scattering (SERS) methodology with its unique ability to collect abundant intrinsic fingerprint information and noninvasive data acquisition we set up a SERS-based approach for recognition of physically induced DNA damage with further incorporation of artificial neural network (ANN). As a proof-of-concept application, we used the DNA molecules, where the one oligonucleotide (OND) was grafted to the plasmonic surface while complimentary OND was exposed to UV illumination with various exposure doses and further hybridized with the grafted counterpart. All SERS spectra of entrapped DNA were collected by several operators using the portable spectrometer, without any optimization of measurements procedure (e.g., optimization of acquisition time, laser intensity, finding of optimal place on substrate, manual baseline correction, etc.) which usually takes a significant amount of operator's time. The SERS spectra were employed as input data for ANN training, and the performance of the system was verified by predicting the class labels for SERS validation data, using a spectra dataset, which has not been involved in the training process. During that phase, accuracy higher than 98% was achieved with a level of confidence exceeding 95%. It should be noted that utilization of the proposed functional-SERS/ANN approach allows identifying even the minor DNA damage, almost invisible by control measurements, performed with common analytical procedures. Moreover, we introduce the advanced ANN design, which allows not only classifying the samples but also providing the ANN analysis feedback, which associates the spectral changes and chemical transformations of DNA structure.

Protective Effects of Timosaponin AIII against UVB-Radiation Induced Inflammation and DNA Injury in Human Epidermal Keratinocytes.

UVB radiation changes several photoaging pathway in the body, thereby prompting skin injury. Besides, chronic UVB radiation leads to photoaging, sustained immunosuppression, and photocarcinogenesis. We investigated the protective effect of Timosaponin AIII (TA-III), a naturally occurring steroidal saponin separated from Anemarrhena asphodeloides, against UVB-induced invasive properties of human epidermal keratinocytes (HEKs) and human dermal fibroblasts (HDF). No cytotoxicity was observed up to 50 nM concentration of TA-III. Similarly, TA-III inhibited UVB-induced cyclooxygenase-2 (COX-2), matrix metalloproteinase-9 (MMP-9) transcription level and protein expression in a dose-dependent manner at non-cytotoxic dose. Further, TA-III decreased UVB-induced invasion in primary skin cells. Additionally, TA-III suppressed UVB-stimulates mitogen-activated protein kinase (MAPK) signaling, activator protein-1 (AP-1) and nuclear factor kappa B (NF-κB) activation, thereby preventing the overexpression of tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), and COX-2 in human epidermal keratinocytes cells. Furthermore, TA-III prevented UVB-mediated formation of 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxo-dG) and activation of DNA repair enzymes and, cell cycle arrest genes like as proliferating cell nuclear antigen (PCNA), structural maintenance of chromosomes protein 1 (SMC1). This results support that understanding into the molecular action of TA-III, which can be useful for developing photoprotective agents.

Phototoxicity of 7-oxycoumarins with keratinocytes in culture.

Seventy-one 7-oxycoumarins, 66 synthesized and 5 commercially sourced, were tested for their ability to inhibit growth in murine PAM212 keratinocytes. Forty-nine compounds from the library demonstrated light-induced lethality. None was toxic in the absence of UVA light. Structure-activity correlations indicate that the ability of the compounds to inhibit cell growth was dependent not only on their physiochemical characteristics, but also on their ability to absorb UVA light. Relative lipophilicity was an important factor as was electron density in the pyrone ring. Coumarins with electron withdrawing moieties - cyano and fluoro at C3 - were considerably less active while those with bromines or iodine at that location displayed enhanced activity. Coumarins that were found to inhibit keratinocyte growth were also tested for photo-induced DNA plasmid nicking. A concentration-dependent alteration in migration on neutral gels caused by nicking was observed.

Consumption of ellagic acid and dihydromyricetin synergistically protects against UV-B induced photoaging, possibly by activating both TGF-ß1 and wnt signaling pathways.

Ellagic acid (EGA) and dihydromyricetin (DHM) are both found in fruits and vegetables are used for anti-aging treatment for the skin. The anti-photoaging efficacy of EGA and DHM was investigated in UV-B irradiated skin in vivo and the involvement of transforming growth factor (TGF)-ß1 and wnt signaling pathways were examined in vitro. HaCaT cells were treated with either 50µM EGA, 50µM DHM or 25µM EGA+25µM DHM before 100mJ/cm2 UV-B exposure, and then oxidative stress and inflammation was measured. The involvement of TGF-ß1 and wnt signaling was measured using their inhibitors, respectively, in HaCaT cells. Mice were fed a high fat diet with either 0.7% cellulose, 0.7% EGA, 0.7% DHM or 0.35% EGA+0.35% DHM for 3weeks and the dorsal skin of the mice had UV-B irradiation. 3% cellulose, 3% EGA, 3% DHM or 1.5% EGA+1.5% DHM in 1,3-buthylene glycol was applied onto the dorsal skin at 30min before 1 MED UV-B exposure. In 100mJ/cm2 UVB irradiation, EGA and DHM mainly decreased oxidative stress and inflammation, respectively in HaCaT cells. Their activities were blocked by the TGF-ß1 inhibitor, indicating their actions were mediated by TGF-ß1 signaling (TGF-ß1➔pSmad3➔Smad7). DHM enhanced wnt signaling by increasing ß-catenin and decreasing Dickkopf-related protein-1. In mice, 1 MED UV-B exposure induced sunburn, redness, and blistering. EGA, DHM and especially EGA+DHM lessened their severity. UV-B increased epidermal thickness and damaged epidermal nucleus and cell structures. DHM and especially EGA+DHM prevented damage to the nucleus and cell structures. Expressions of circulating and dorsal skin IL-1ß and TNF-α mRNA were lower in descending order of: control, EGA, DHM, EGA+DHM and normal-control. In conclusion, the consumption of EGA+DHM had a synergistically protective action against UV-B damage in the skin tissues of mice and HaCaT cells, and it may be associated with activating of both TGF-ß1 and wnt signaling.

Clinical evaluation of the efficacy and safety of combined bipolar radiofrequency and optical energies vs. optical energy alone for the treatment of aging hands.

Different treatment modalities are used for the treatment and esthetic improvement of aging hands. This study evaluated the efficacy and safety of a novel technology, which combines bipolar radio frequency (RF) and optical energies for the cosmetic treatment of aging hands. The objective of the study was to assess the efficacy, safety, tolerability, and patient satisfaction of combined bipolar radiofrequency and optical energies vs. optical energy alone for the treatment of aging hands. Thirteen female patients with solar lentigines on the back of the hands were enrolled. Participants received three treatments: combined RF and intense pulsed light (IPL) on one hand and IPL treatment alone on the other. Standardized clinical photographs were taken, and patient and investigator improvement assessment (Global Esthetic Improvement (GAI) scale), patient satisfaction, and tolerability were evaluated. At the 1 and 3 months follow-up, skin laxity and pigmentation, investigator and patient improvement assessments, and satisfaction were significantly better in the hand treated with combined bipolar RF and IPL. This study demonstrates the safety and efficacy of combining RF and optical energies for the esthetic improvement of aging hands. Combined RF and IPL treatment was more efficient than IPL alone in improving skin pigmentation, skin laxity, and texture.

Repression effect of metformin on photo-damage of human skin fibroblasts induced by UVA / 基础医学与临床

Objective To determine the inhibitory effect and mechanism of metformin ( MF) on photo-damage of human skin fibroblasts ( HSF) induced by UVA .Methods Human skin fibroblasts were randomly divided into con-trol group, UVA group and UVA+MF group.The proliferation of HSF was detected by CCK-8 assay kit.SA-β-gal staining was performed to evaluate the senescence state .The level of ROS was examined by fluorescence probe DCF-DA staining using flow cytometry .Real-time PCR was used to determine mRNA expression of senescence -asso-ciated signals of MMP 1 and MMP3.The protein expression of MMP 1, MMP3, SOD1 and SOD2 were measured by Western blot .R esults To the proliferation of HSF , 0.01 mmol/L Metformin had no significant effect , but 0.1 and 1 mmol/L Metformin depressed significantly ( P<0.05 ) .Compared with the Control group , it showed that UVA irradiation increased the positive rate of SA-β-gal staining ( P<0.01 ) , the level of ROS ( P<0.05 ) , mRNA and protein expression of MMP1 and MMP3 significantly(P<0.01);Also decreased the expression of SOD1 and SOD2 ( P<0.01) .Compared with the UVA group , it showed that metformin decreased the positive rate of SA-β-gal staining (P<0.05), the level of ROS(P<0.05), mRNA and protein expression of MMP1 and MMP3 significantly(P<0.05);Also increased the expression of SOD 1 ( P<0.01 ) and SOD2.Conclusions Metfomin can inhibit photo-damage of human skin fibroblasts induced by UVA via decreasing ROS and metal matrix protease generation , also the improvement of cellular antioxidant capacity .

Yellowing and bleaching of grey hair caused by photo and thermal degradation.

Yellowing is an undesirable phenomenon that is common in people with white and grey hair. Because white hair has no melanin, the pigment responsible for hair colour, the effects of photodegradation are more visible in this type of hair. The origin of yellowing and its relation to photodegradation processes are not properly established, and many questions remain open in this field. In this work, the photodegradation of grey hair was investigated as a function of the wavelength of incident radiation, and its ultrastructure was determined, always comparing the results obtained for the white and black fibres present in grey hair with the results of white wool. The results presented herein indicate that the photobehaviour of grey hair irradiated with a mercury lamp or with solar radiation is dependent on the wavelength range of the incident radiation and on the initial shade of yellow in the sample. Two types of grey hair were used: (1) blended grey hair (more yellow) and (2) grey hair from a single-donor (less yellow). After exposure to a full-spectrum mercury lamp for 200 h, the blended white hair turned less yellow (the yellow-blue difference, Db(*) becomes negative, Db(*)=-6), whereas the white hair from the single-donor turned slightly yellower (Db(*)=2). In contrast, VIS+IR irradiation resulted in bleaching in both types of hair, whereas a thermal treatment (at 81 °C) caused yellowing of both types of hair, resulting in a Db(*)=3 for blended white hair and Db(*)=9 for single-donor hair. The identity of the yellow chromophores was investigated by UV-Vis spectroscopy. The results obtained with this technique were contradictory, however, and it was not possible to obtain a simple correlation between the sample shade of yellow and the absorption spectra. In addition, the results are discussed in terms of the morphology differences between the pigmented and non-pigmented parts of grey hair, the yellowing and bleaching effects of grey hair, and the occurrence of dark-follow reactions.

Protective effects of aucubin on keratinocyte damaged by Ultraviolet B / 中国药学杂志

OBJECTIVE: To investigate the protection of aucubin on keratinocyte damaged by Ultraviolet B and explore its possible mechanism. METHODS: The photo damage model of keratinocyte was established by irradiating of UVB (64 mJ · cm-1). The different concentration aucubin were used for damaged cell. The cell viability was detected by MTT, the SOD activity, GSH-Px activity, CAT activity, MDA content were assayed by kit respectively. The mRNA levels of P38, TNF-α and IL-6 were determined by RT-PCR. The secretion levels of TNF-α and IL-6 of cultured keratinocyte were detected by ELISA. RESULTS: After the UVB irradiation, the cell viability, the activities of SOD, GSH-Px and CAT were decreased, the content of MDA, TNF-α and IL-6, the mRNA levels of P38, TNF-α and IL-6 were increased (P < 0.01). The above changes were inhibited by 1 × 10-1 and 1 × 10-1 mol · L-1 aucubin (P < 0.05 or P < 0.01). CONCLUSION: The aucubin could inhibit the injury by UVB for keratinocyte. And its possible mechanism may have relationship with the inhibition of oxidative damage, regulatory P38 signal pathway, adjusting the expression of TNF-α and IL-6.

Hydrogen-rich saline protects against ultraviolet B radiation injury in rats.

Exposure of skin to solar ultraviolet (UV) radiation induces photo-damage. Ultraviolet B (UVB) is the major component of UV radiation which induces the production of reactive oxygen species (ROS) and plays an important role in photo-damage. Hydrogen gas reduces ROS and alleviates inflammation. In this study, we sought to demonstrate that hydrogen-rich saline has the effect on skin injuries caused by UVB radiation. UVB radiation was irradiated on female C57BL/6 rats to induce skin injury. Hydrogen-rich saline and nitrogen-rich saline were administered to rats by intraperitoneal injection. Skin damage was detected by microscope after injury. UVB radiation had a significant affection in tumor necrosis factor alpha, interleukin (IL)-1ß and IL-6 levels, tissue superoxide dismutase, malondialdehyde and nitric oxide activity. Hydrogen-rich saline had a protective effect by altering the levels of these markers and relieved morphological skin injury. Hydrogen-rich saline protected against UVB radiation injury, possibly by reducing inflammation and oxidative stress.