The Effect of Sunscreen on Skin Elastase Activity Induced by Ultraviolet-A Irradiation

Effects of collagen hydrolysates on UV-induced photoaging mice: Gly-Pro-Hyp as a potent anti-photoaging peptide

This work aimed to investigate the protective effects of collagen hydrolysates containing different contents of Gly-Pro-Xaa tripeptides on UV-induced photoaging mice and to identify potent anti-photoaging peptides. Results showed that oral ingestion of collagen hydrolysates with a higher content of Gly-Pro-Xaa tripeptides (∼11.4%, HCH) dramatically enhanced the absorption of Pro-Hyp, Hyp-Gly, and Gly-Pro-Hyp into the body, which were 1.77-, 2.18-, and 65.07-fold higher in area under the concentration-time curve (AUC) values than that of collagen hydrolysates with a lower content of Gly-Pro-Xaa tripeptides (∼3.8%, LCH), respectively. Furthermore, the protective effects of HCH on the photo-aged skin of mice were significantly stronger than those of LCH in terms of increases in the contents of hyaluronic acid and collagen, improvement in skin elasticity and epidermal thickness, alleviation in inflammation, and decreases in the contents of matrix metalloproteinase-1 (MMP-1) and MMP-3. More importantly, Gly-Pro-Hyp displayed potent anti-photoaging activities comparable to HCH based on an equivalent amount of Hyp. Network pharmacology analysis for potential mechanisms further indicated that Gly-Pro-Hyp might interact with JUN and FOS and regulate IL-17 and TNF signaling pathways. Collectively, our results suggested that HCH had great potential to be applied in functional foods for skin health and Gly-Pro-Hyp was found to be a potent collagen-derived anti-photoaging peptide, which might contribute to the excellent anti-photoaging effects of HCH.

Oroxylin A ameliorates ultraviolet radiation-induced premature skin aging by regulating oxidative stress via the Sirt1 pathway

Skin is susceptible to premature aging in response to ultraviolet (UV) radiation-induced oxidative stress, which can ultimately result in aberrant aging or age-related disorders. Accordingly, strategies that can be adopted to mitigate oxidative stress may contribute to protecting skin from induced aging-related damage, thereby offering promising approaches for the treatment of skin diseases and disorders. In this regard, oroxylin A (OA), a natural flavonoid isolated from certain plants used in traditional Chinese medicine, is considered to have notable antioxidant, anti-inflammatory, and anti-apoptotic properties, and is often used to treat certain inflammatory diseases. To date, however, there has been comparatively little research on the effects of OA with respect skin aging. In this study, we utilized UV radiation-induced mouse and cellular models of aging to assess the efficacy of OA in protecting against skin aging. Subsequently, to elucidate the potential mechanisms underlying the protective effect of OA on skin aging, we performed molecular docking analysis to investigate the involvement of the anti-aging gene Sirt1, which was further confirmed on the basis of Sirt1 gene silencing. We accordingly demonstrated that by promoting an increase in the expression of Sirt1, OA can contribute to suppressing UV-induced skin photo-aging in cells/mice by reducing oxidative stress. Furthermore, we established that by activating Sirt1, OA can also promote the dissociation of Nrf2 from Keap1 and its subsequent nuclear translocation. Collectively, our findings in this study reveal OA to be an effective natural compound that can be administered to delay the aging of skin triggered by UV, both in vivo and in vitro, by binding to Sirt1 to promote the deacetylation and nuclear translocation of Nrf2, thereby contributing to a reduction in oxidative stress. These findings may this provide a therapeutic target for the prevention of skin aging or aging-induced skin diseases.

Anti-aging formula protects skin from oxidative stress-induced senescence through the inhibition of CXCR2 expression

ETHNOPHARMACOLOGICAL RELEVANCE

The skin is affected by endogenous and exogenous factors, which are the intuitive consequence expression of aging. Aging not only affects the aesthetics of the skin but also causes the decline of skin functions, leading to many skin diseases and even skin cancer. Anti-aging formula (AAF) has various biological effects such as antioxidants, regulation of intestinal flora metabolism, anti-aging, and memory improvement. However, it is not clarified whether it could be anti-aging of the skin and the anti-aging mechanism.

AIM OF THE STUDY

This study aimed to investigate whether AAF could prevent skin from oxidative stress-induced senescence and explore the underlying molecular mechanisms.

MATERIALS AND METHODS

A mouse skin oxidative stress aging model was established based on ultraviolet (UV) irradiation, and parameters such as skin water content, melanogenesis, wrinkle production, pathological changes, and aging marker proteins were measured to elucidate whether AAF has an anti-aging effect on the skin. Subsequently, transcriptome sequencing (RNA-Seq) was used to identify target genes. An in vitro cellular senescence model was established to assess the role of AAF against cellular oxidative stress senescence by detecting senescence-related markers, while the specific mechanism of action of AAF in delaying skin senescence was elucidated by silencing or overexpression of targets.

RESULTS

In vivo experiments demonstrated that AAF significantly increased skin water content, reduced skin sensitivity and melanin content, slowed wrinkles, improved UV-induced epidermal thickening, increased collagen fiber content, improved elastic fiber morphology, and reduced the expression of senescence proteins P21 and P16 in skin tissues. The RNA-Seq results identified chemokine receptor 2 (CXCR2) as one of the potential targets for delaying skin senescence. In vitro experiments showed that AAF markedly improved the aging phenotype, and knockdown or overexpression experiments verified the essential role of CXCR2 in the skin senescence process. Mechanistic studies suggested that AAF inhibited the P38/P53 pathway by reducing CXCR2 expression, which improved the aging phenotype, reduced oxidative damage, and ultimately delayed cellular senescence.

CONCLUSION

The results reveal that AAF protects skin from oxidative stress-induced senescence by regulating the expression of critical target CXCR2, reducing P38 protein phosphorylation, and inhibiting P53 pathway activation. These discoveries implicate the potential of AAF in the protection of skin aging disease.

Investigating the efficacy of topical application of Ipomoea carnea herbal cream in preventing skin damage induced by UVB radiation in a rat model

Ultraviolet-B irradiation is a common environmental stressor that has detrimental effects on human skin. Natural sunscreens are well-known for their ability to benefit inflamed sunburn and dry skin. This study examined the effect of formulated Ipomoea carnea herbal cream on UVB-induced skin damage. We screened the bioactive compounds of I. carnea crude extract, showing significant antioxidant activity. Additionally, we evaluated the cytotoxicity, revealing that I. carnea extract has less toxicity to vero cells (IC50 98.45 μg/mL) than to A375 cells (IC50 48.95 μg/mL). Based on this, we formulated the I. carnea herbal cream (FIHC) at 50, 100 and 200 mg concentrations and evaluated its organoleptic characteristics. Then, the rats were exposed to UVB radiation (32,800 J/m2) four times/week (on alternate days) before the cream was applied topically to the dorsal skin surface. Under UVB stress without treatment, rats showed deep dermal damage. In contrast, rats treated with the FIHC exhibited significantly reduced sunburn. Moreover, the histopathological and biochemical assays were confirmed by the topical application of FIHC, which had potentially reduced the skin elasticity and maintained the imbalanced enzyme and non-enzymatic antioxidant activity. Our findings amply demonstrate that the FIHC significantly accelerated the recovery of UVB-induced lesions through antioxidant and down-regulation of skin photodamage.

Solid-in-oil nanodispersion as a novel topical transdermal delivery to enhance stability and skin permeation and retention of hydrophilic drugs l-ascorbic acid

l-ascorbic acid （Vitamin C, VC） is the most abundant antioxidant in human skin. But its poor penetration into the skin and unstability limit the application. The aim of the study was to promote the topical skin permeation and retention of VC, increase the stability as well as effectiveness by a novel solid in oil nanodispersion. In the nanodispersions system, nano-sized particles of hydrophilic molecules are dispersed in an oil vehicle with the assistance of hydrophobic surfactants. The optimized formula composed of O170 and S1570 (12.5:1, w/w) showed high EE% of 98% and good stability. FTIR analysis confirmed that there may be hydrogen bond between VC and surfactants. The results of DSC, and XRD revealed that the drug was successfully encapsulated in the surfactants, which maintained the stability of drug. By analyzing and fitting the release data in vitro, the drug release mechanism of SONDs was predicted as a multi-dynamic model. Skin permeation of VC was improved 3.43-fold for SONDs compared with VC aqueous solution, highlighting that the lipophilicity and nano size of the carrier more easily penetrated into the skin. Finally, the photoaging study revealed that topical application of VC-SONDs provided the highest skin protection compared UV and VC aqueous solution treated group which was evident by the normal thick epidermal morphology, no obvious melanocytes and the densely arranged dermal elastic fibers. These results demonstrated that the solid-in-oil nanodispersions may be a potential transdermal delivery system for hydrophilic bioactive ingredients.

Modified Qing’e Formula protects against UV-induced skin oxidative damage via the activation of Nrf2/ARE defensive pathway

Exposure to ultraviolet (UV) light triggers the rapid generation and accumulation of reactive oxygen species (ROS) in skin cells, which increases oxidative stress damage and leads to photoaging. Nuclear factor E2-related factor 2 (Nrf2) modulates the antioxidant defense of skin cells against environmental factors, especially ultraviolet radiation. Natural products that target Nrf2-regulated antioxidant reactions are promising candidates for anti-photoaging. The aim of this study was to investigate the protective effect of Modified Qing’e Formula (MQEF) on UV-induced skin oxidative damage and its molecular mechanisms. In this study, the photoaging models of human keratinocytes (HaCaT) and ICR mice were established by UV irradiation. In vitro models showed that MQEF displayed potent antioxidant activity, significantly increased cell viability and reduced apoptosis and excess ROS levels. Meanwhile, the knockdown of Nrf2 reversed the antioxidant and anti-apoptotic effects of MQEF. In vivo experiments indicated that MQEF could protect the skin against UV-exposed injury which manifested by water loss, sensitivity, tanning, wrinkling, and breakage of collagen and elastic fibers. The application of MQEF effectively increased the activity of antioxidant enzymes and reduced the content of malondialdehyde (MDA) in mice. In addition, MQEF was able to activate Nrf2 nuclear translocation in mouse skin tissue. In summary, MQEF may attenuate UV-induced photoaging by upregulating Nrf2 expression and enhancing antioxidant damage capacity. MQEF may be a potential candidate to prevent UV-induced photoaging by restoring redox homeostasis.

Effect of boron element on photoaging in rats

BACKGROUND

The present study further assessed the effects of oral and topical applications of boron, which is known to have antiinflammatory and wound healing effects, on photoaging.

METHODS

A total of 49 eight-week-old female Wistar albino rats randomly divided into seven groups (control, shaved control, shaved+UVB, topical dermabor 2% (D2), and %5 (D5), systemic sodium perborate tetrahydrate (SPT) 2% (SPT2) and 4% (SPT4). To induce an experimental photoaging, the rats were exposed to UVB at an emission spectrum of 290-320 nm. Biochemical, molecular, skin, histological, and collagen content analyzes were made at the end of the study.

RESULTS

Increased skin inflammatory parameters (COX-2, IL-8, NF-KB, IL-6, and TNF-α) levels in UVB-exposed groups were inhibited in all treatment groups. The tissue level of hydroxyproline and elastase was found to decrease in all UVB-exposed group. The level of hydroxyproline was significantly higher in the D2 and D5 groups than in the SPT2 and SPT4 groups. The level of elastase was significantly lower in the D2 and D5 groups than in the SPT2 and SPT4 groups.

CONCLUSIONS

In future, boron may be developed as a functionally protective treatment against photoaging caused by UVB, and may be included in sun protection systems.

Application and Efficacy of Melatonin Elastic Liposomes in Photoaging Mice

Transdermal drug delivery system is a preferable choice to overcome the low bioavailability of oral medication. Elastic liposomes have shown great effectiveness for percutaneous transport of melatonin (MLT). In this study, the elastic liposomes loaded with MLT were prepared using thin-film dispersion method and optimized through the central composite design (CCD) approach. The physicochemical properties and skin permeation against UV-induced skin photoaging efficacy of the developed MLT-ELs were assessed. The average size of the MLT-ELs was about 49 nm with a spherical shape and high encapsulation efficiency (73.91%) and drug loading (9.92%). The results of FTIR, DSC, and XRD revealed that the chemical structure of MLT was not changed after prepared elastic liposomes, and the drug was successfully encapsulated in the elastic liposome membrane material. In vitro skin permeation evaluation showed that the cumulative penetration of elastic liposomes was 1.5 times higher than that of conventional liposomes, highlighting that the elastic liposomes more easily penetrated into the body. The photoaging experiment results indicated that topical MLT-EL treatment ameliorated the skin elasticity, enhanced the skin hydration level, and preserved the integrity of dermal collagen and elastic fibers. It could be concluded that the elastic liposomes might serve as a promising platform for the transdermal delivery of melatonin.

Anti-Aging Effects of a Serum Based on Coconut Oil Combined with Deer Antler Stem Cell Extract on a Mouse Model of Skin Aging

Anti-aging is one of the top goals in the field of health care and aesthetics. Anti-aging cosmetics derived from nature are oriented to long-term development, bringing safety to users and being environmentally friendly. The aim of this study was to develop an anti-aging cosmetic formulation process based on coconut oil in combination with deer antler stem cell extract. The results show that the presence of deer antler stem cell extract added to the foundation made the serum product highly stable and helped improve skin aging significantly after 2 weeks of use. The skin site where the serum product was applied showed a smooth and elastic skin surface, with very few fine lines and shallow wrinkles. Serum reduced the number of wrinkles (48.09% compared to commercial serum (ME) and 60.31% compared to positive control (PC)), reduced skin recovery time (39.31% compared to ME and 67.1% of PC) after two weeks of use. After 2 weeks of use, collagen density increased 10.18% compared to ME and 63.76% compared to control. Epidermal thickness increased by 106.1% compared to PC and 121.7% compared to ME.

The Protective Effects of a Combination of an Arginine Silicate Complex and Magnesium Biotinate Against UV-Induced Skin Damage in Rats

The purpose of this study was to observe the effects of a novel combination of inositol-stabilized arginine silicate complex (ASI) and magnesium biotinate (MgB) on the prevention of skin damage after UVB exposure in rats. Forty-nine Sprague-Dawley rats were randomized into one of the following groups: (1) NC, normal control, (2) SC, shaved control, (3) UVB (exposed to UVB radiation), (4) ASI+MgB-L (Low Dose), (5) ASI+MgB-H (High Dose), (6) ASI+MgB-L+MgB cream, (7) ASI+MgB-H+MgB cream. The results showed that ASI+MgB treatment alleviated the macroscopic and histopathological damages in the skin of rats caused by UVB exposure. Skin elasticity evaluation showed a similar trend. ASI+MgB increased serum Mg, Fe, Zn, Cu, Si, biotin, and arginine concentrations and skin hydroxyproline and biotinidase levels while decreasing skin elastase activity (p < 0.05) and malondialdehyde (MDA) concentration (p < 0.001). Moreover, ASI+MgB treatment increased skin levels of biotin-dependent carboxylases (ACC1, ACC2, PC, PCC, MCC) and decreased mammalian target of rapamycin (mTOR) pathways and matrix metalloproteinase protein levels by the regulation of the activator protein 1 (AP-1), and mitogen activated protein kinases (MAPKs) signaling pathways. In addition, ASI+MgB caused lower levels of inflammatory factors, including TNF-α, NFκB, IL-6, IL-8, and COX-2 in the skin samples (p < 0.05). The levels of Bax and caspase-3 were increased, while anti-apoptotic protein Bcl-2 was decreased by UVB exposure, which was reversed by ASI+MgB treatment. These results show that treatment with ASI and MgB protects against skin damage by improving skin appearance, elasticity, inflammation, apoptosis, and overall health.

Ultraviolet A-induced oxidation in cornea: Characterization of the early oxidation-related events

Exposure to sunlight ultraviolet-A (UVA), the main component of solar UV reaching the eyes, is suspected to play an important part in the onset of ocular pathologies. UVA primary biological deleterious effects arise from the photo-induction of oxidative stress in cells. However, the molecular bases linking UVA-induced oxidation to UVA toxicity in eyes remain poorly understood, especially with regards to the cornea. To shed some light on this issue, we have investigated the susceptibility and response potential of the different corneal cellular layers (epithelium, stroma and endothelium) to UVA-induced oxidation. We have monitored UVA-induced immediate effects on cellular redox balance, on mitochondrial membrane potential, on 8-Hydroxy-2'-deoxyguanosine (8-OHdG) accumulation in cellular DNA and on S-glutathionylated proteins (PSSG) levels along whole rabbit corneas. Higher redox imbalance was observed in the posterior part of the cornea following irradiation. Conversely, UVA-altered mitochondrial membrane potentials were observed only in anterior portions of the cornea. UVA-induced 8-OHdG were found in nuclear DNA of epithelia, while they were found in both nuclear and mitochondrial DNA in stromal and endothelial cells. Finally, significantly higher levels of cytosolic PSSG were measured in epithelia and endothelia immediately after UVA exposure, but not in stromas. Taken together, our findings indicate that while corneal epithelial cells are subjected to important modifications in response to UVA exposure, they efficiently limit the early manifestations of UVA-induced toxicity. On the other hand, the corneal endothelium is more susceptible to UVA-induced oxidation-related toxicity.

Photo-protective activity of pogostone against UV-induced skin premature aging in mice

Pogostone, a chemical constituent of patchouli oil, has been confirmed to possess favorable anti-inflammatory property. In the present study, we investigated the possible anti-photoaging potential of pogostone and the underlying mechanism against UV-induced skin damage in mice. The macroscopic and histopathological lesions were significantly ameliorated by pretreatment of pogostone as compared to the VC group. Furthermore, topical application of pogostone markedly increased the activities of the antioxidant enzymes, including catalase (CAT), superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px), and observably decreased malonaldehyde (MDA) level. Analysis of inflammatory cytokines showed obvious down-regulation of tumor necrosis factor-alpha (TNF-α), interleukin-6 (IL-6), interleukin-1β (IL-1β) and cyclooxygenase-2 (COX-2), prostaglandin E2 (PGE2) in the pogostone groups. In addition, pogostone pretreatment evidently inhibited the abnormal expression of matrix metalloproteinases (MMP-1 and MMP-3). Taken together, pogostone exhibited prominent photo-protective activity mainly by its antioxidative and anti-inflammatory properties, promising it as an effective alternative pharmaceutical therapy for photoaging.

Andrographolide Sodium Bisulfate Prevents UV-Induced Skin Photoaging through Inhibiting Oxidative Stress and Inflammation

Andrographolide sodium bisulfate (ASB), a water-soluble form made from andrographolide through sulfonating reaction, is an antioxidant and anti-inflammatory drug; however, the antiphotoaging effect of ASB has still not been revealed. Oxidative stress and inflammation are known to be responsible for ultraviolet (UV) irradiation induced skin damage and consequently premature aging. In this study, we aimed at examining the effect of ASB on UV-induced skin photoaging of mice by physiological and histological analysis of skin and examination of skin antioxidant enzymes and immunity analyses. Results showed that topical administration of ASB suppressed the UV-induced skin thickness, elasticity, wrinkles, and water content, while ASB, especially at dose of 3.6 mg/mouse, increased the skin collagen content by about 53.17%, decreased the epidermal thickness by about 41.38%, and prevented the UV-induced disruption of collagen fibers and elastic fibers. Furthermore, ASB decreased MDA level by about 40.21% and upregulated the activities of SOD and CAT and downregulated the production of IL-1β, IL-6, IL-10, and TNF-α in UV-irradiated mice. Our study confirmed the protective effect of ASB against UV-induced photoaging and initially indicated that this effect can be attributed to its antioxidant and anti-inflammatory activities in vivo, suggesting that ASB may be a potential antiphotoaging agent.

Protective Effect of Super-Critical Carbon Dioxide Fluid Extract from Flowers and Buds of Chrysanthemum indicum Linnén Against Ultraviolet-Induced Photo-Aging in Mice

It is known that solar ultraviolet (UV) radiation to human skin causes photo-aging, including increases in skin thickness and wrinkle formation and reduction in skin elasticity. UV radiation induces damage to skin mainly by superfluous reactive oxygen species and chronic low-grade inflammation, which eventually up-regulate the expression of matrix metalloproteinases (MMPs). In this study, the super-critical carbon dioxide extract from flowers and buds of Chrysanthemum indicum Linnén (CISCFE), which has been reported to possess free radical scavenging and anti-inflammatory properties, was investigated for its photo-protective effect by topical application on the skin of mice. Moreover, CISCFE effectively suppressed the UV-induced increase in skin thickness and wrinkle grading in a dose-dependent manner, which was correlated with the inhibition of loss of collagen fiber content and epidermal thickening. Furthermore, we observed that CISCFE could obviously decrease UV-induced skin inflammation by inhibiting the production of inflammatory cytokines (interleukin-1β [IL-1β, IL-6, IL-10, tumor necrosis factor-α), alleviate the abnormal changes of anti-oxidative indicators (superoxide dismutase, catalase, and glutathione peroxidase), and down-regulate the levels of MMP-1 and MMP-3. The results indicated that CISCFE was a novel photo-protective agent from natural resources against UV irradiation.

Skin aging modulates percutaneous drug absorption: the impact of ultraviolet irradiation and ovariectomy

Ultraviolet (UV) exposure and menopause are known as the inducers of damage to the skin structure. The combination of these two factors accelerates the skin aging process. In this study, we aimed to evaluate the influence of UV and ovariectomy (OVX) on the permeation of drugs through the skin. The role of tight junctions (TJs) and adherens junctions (AJs) in the cutaneous absorption of extremely lipophilic permeants and macromolecules was explored. The OVX nude mouse underwent bilateral ovary removal. Both UVA and UVB were employed to irradiate the skin. The physiological and biochemical changes of the skin structure were examined with focus on transepidermal water loss (TEWL), skin color, immunohistochemistry, and mRNA levels of proteins. UVB and OVX increased TEWL, resulting in stratum corneum (SC) integrity disruption and dehydration. A hyperproliferative epidermis was produced by UVB. UVA caused a pale skin color tone due to keratinocyte apoptosis in the epidermis. E-cadherin and β-catenin showed a significant loss by both UVA and UVB. OVX downregulated the expression of filaggrin and involucrin. A further reduction was observed when UV and OVX were combined. The in vitro cutaneous absorption demonstrated that UV increased the skin permeation of tretinoin by about twofold. However, skin accumulation and flux of estradiol were not modified by photoaging. OVX basically revealed a negligible effect on altering the permeation of small permeants. OVX increased tretinoin uptake by the appendages from 1.36 to 3.52 μg/cm(2). A synergistic effect on tretinoin follicular uptake enhancement was observed for combined UV and OVX. However, the intervention of OVX to photoaged skin resulted in less macromolecule (dextran, molecular weight = 4 kDa) accumulation in the skin reservoir because of retarded partitioning into dry skin. The in vivo percutaneous absorption of lipophilic dye examined by confocal microscopy had indicated that the SC was still important to controlling topical delivery, although the role of epidermal junctions could not be simply ignored.

The protective effect of 18β-Glycyrrhetinic acid against UV irradiation induced photoaging in mice

It has been confirmed that repeated exposure of skin to ultraviolet (UV) radiation results in cutaneous oxidative stress and inflammation, which act in concert to cause premature skin aging, well known as photoaging. 18β-Glycyrrhetinic acid (GA), widely used to treat various tissue inflammations, is the main active component of licorice root, and has also been shown to possess favorable anti-oxidative property and modulating immunity function. In the present study, we investigated the potential protective effect of GA on UV-induced skin photoaging in a mouse model. During the experimental period of ten consecutive weeks, the dorsal depilated skin of mice was treated with topical GA for 2 hours prior to UV irradiation. The results showed that GA pretreatment significantly alleviated the macroscopic and histopathological damages in mice skin caused by UV. Meanwhile, the data also indicated that GA markedly up-regulated the activities of the antioxidant enzymes (SOD, GSH-Px), and increased the content of skin collagen, while obviously decreased malonaldehyde level and inhibited high expressions of matrix metalloproteinase-1 (MMP-1) and -3 (MMP-3), as well as down-regulated the expression of inflammatory cytokines such as IL-6, TNF-α and IL-10. Taken together, these findings amply demonstrate that GA observably attenuates UV-induced skin photoaging mainly by virtue of its antioxidative and anti-inflammatory properties, as well as regulating the abnormal expression of MMP-1 and MMP-3.

Extract of the mycelium of T. matsutake inhibits elastase activity and TPA-induced MMP-1 expression in human fibroblasts

Skin aging is induced through complex biological processes in human skin caused by proteolysis of collagen and elastin, two structural proteins of the dermal extracellular matrix (ECM). Collagen and elastin degradation can induce the expression of matrix metalloproteinases (MMPs), as well as that of a family of zinc-dependent endopeptidases that play critical roles in skin aging. Moreover, elastase is a metalloproteinase which acts on the degradation of elastin in skin aging, and is also involved in the inhibition or the repair of wrinkle formation. Extract of the mycelium of Tricholoma matsutake (T. matsutake), or pine mushroom, is widely distributed in Asian countries. The extract is from the natural biomaterial of the mushroom which is rich in polysaccharides, including β-glucan. This extract has shown potent bioactive antioxidant, immunomodulatory and antitumoral properties. In the present study, we investigated whether the extract of the mycelium of T. matsutake has effects on elastase activity, as well as on the expression of tissue inhibitor of matrix metalloproteinases-1 (TIMP-1) and MMP-1 under basal conditions. Our results revealed that the extract of the mycelium of T. matsutake significantly decreased elastase activity in a dose-dependent manner and reduced the levels of MMP-1 and MMP-3. On the other hand, the expression of TIMP-1 and tropoelastin was increased in fibroblasts treated with the extract of the mycelium of T. matsutake. However, collagent expression was not affected. In addition, our results demonstrated that the extract of the mycelium of T. matsutake inhibited the 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced MMP-1 expression and suppressed TPA-induced p38 activity. Therefore, the inhibitory effects of the extract of the mycelium of T. matsutake on MMP-1 induction are mediated by the inhibition of p38 in human fibroblasts. Our data suggest that the extract of the mycelium of T. matsutake may prove to be an effective biomaterial for anti-wrinkle treatment, as it can obstruct the degradation of the dermal ECM.

Effects of topical application of patchouli alcohol on the UV-induced skin photoaging in mice

Ultraviolet (UV) irradiation, known to generate reactive oxygen species (ROS) excessively and elicit inflammatory response, is a potent inducer for skin photoaging. Overproduction of ROS in conjunction with the resulting inflammation stimulate the over-expression of matrix metalloproteinases (MMPs), which in turn causes degradation of extracellular matrix, leading finally to coarse wrinkling, dryness, and laxity of the skin. In this study, patchouli alcohol (PA, C15H26O), an active chemical ingredient reputed for free radical scavenging and anti-inflammatory properties, was investigated for its anti-photoaging action using a mouse model whose dorsal skin was depilated. The dorsal skin areas of six-week-old mice were smeared with PA solution or vehicle, followed by UV irradiation for nine consecutive weeks. Protective effects of PA were evaluated macroscopically and histologically, as well as by assaying the antioxidant enzymes (SOD, GSH-Px) activities, the contents of inflammatory factors (IL-10, IL-6, TNF-α), and the levels of MMP-1 and MMP-3. Our findings amply demonstrated that PA significantly accelerated the recovery of the UV-induced skin lesions, evidently through anti-oxidant and anti-inflammatory action, as well as down-regulation of the MMP-1 and MMP-3 expression.

Inhibitory effect of hydroxysafflor yellow a on mouse skin photoaging induced by ultraviolet irradiation

Chronic exposure to ultraviolet (UV) irradiation is believed to be the major cause of skin damage that results in premature aging of the skin, so called photoaging, characterized by increases in skin thickness, formation of wrinkles, and loss of skin elasticity. UV induces damage to skin mainly by oxidative stress and collagen degradation. In this study, we examined the photo-protective effect of hydroxysafflor yellow A (HSYA), a major active chemical component isolated from Carthamus tinctorius L., by topical application on the skin of mice. Exposure of the dorsal depilated skin of mice to UV radiation four times a week for 10 weeks induced epidermal hyperplasia, elastin accumulation, collagen degradation, etc. HSYA at the doses of 50, 100, and 200 μg/mouse was topically applied immediately following each UV exposure. The effects of HSYA were evaluated by a series of tests, including macroscopic and histopathological evaluation of skin, pinch test, and redox homeostasis of skin homogenates. Results showed that the UV-induced skin damage was significantly improved after HSYA treatment, especially at doses of 100 and 200 μg/mouse. This protective effect is possibly related to the anti-oxidative property of HSYA and mediated by promoting endogenous collagen synthesis. This is the first study providing preclinical evidence for the protective effect of HSYA against photoaging.

Prevention of UV radiation-induced cutaneous photoaging in mice by topical administration of patchouli oil

ETHNOPHARMACOLOGICAL RELEVANCE

Pogostemon cablin has been widely used in traditional Chinese medicine for the treatment of many diseases, including skin disorders. In the skin beauty and care prescriptions, Pogostemon cablin is one of the top ten frequently used traditional Chinese medicines.

AIM OF THE STUDY

The present study was aimed to investigate the protective effects of the essential oil of Pogostemon cablin (patchouli oil, PO) against UV-induced skin photoaging in mice.

MATERIALS AND METHODS

To ensure the quality of PO, the chemical compositions of PO were identified, and the content of its chemical marker patchouli alcohol was determined, which was around 28.2% (g/g) in PO. During the experiment period, the dorsal depilated skin of mice was treated with PO for two hours prior to UV irradiation. Then the protective effects of PO on UV-induced skin photoaging were determined by macroscopic and histological evaluations, skin elastic test, collagen content determination and biochemical assays of malondiaidehyde (MDA) content, activities of anti-oxidative indicators including superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), and catalase (CAT).

RESULTS

Compared to UV exposure groups, present results showed that topical administration of PO, especially at dose of 6mg/mouse and 9mg/mouse, significantly inhibited the increase in skin wrinkle formation, alleviated the reduction in skin elasticity and increased the collagen content by about 21.9% and 26.3%, respectively. We also found that application of 6-9mg/mouse PO could not only decrease the epidermal thickness by about 32.6%, but also prevent the UV-induced disruption of collagen fibers and elastic fibers. Furthermore, the content of MDA was decreased by almost 26.5% and activities of SOD, GSH-Px and CAT were significantly up-regulated after the treatment of PO.

CONCLUSION

Results of present study revealed that PO was capable of maintaining skin structural integrity caused by UV irradiation and it was useful in preventing photoaging. These protective effects of PO were possibly due to its anti-oxidative property. Therefore, we suggested that PO should be viewed as a potential therapeutic agent for preventing photoaging.

The risk of hydroquinone and sunscreen over-absorption via photodamaged skin is not greater in senescent skin as compared to young skin: nude mouse as an animal model

Intrinsic aging and photoaging modify skin structure and components, which subsequently change percutaneous absorption of topically applied permeants. The purpose of this study was to systematically evaluate drug/sunscreen permeation via young and senescent skin irradiated by ultraviolet (UV) light. Both young and senescent nude mice were subjected to UVA (10 J/cm(2)) and/or UVB radiation (175 mJ/cm(2)). Physiological parameters, immunohistology, and immunoblotting were employed to examine the aged skin. Hydroquinone and sunscreen permeation was determined by in vitro Franz cell. In vivo skin absorption was documented using a hydrophilic dye, rhodamine 123 (log P=-0.4), as a permeant. UVA exposure induced cyclooxygenase (COX)-2 and terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) upregulation. Epidermal tight junction (TJ) were degraded by UVA. UVB increased transepidermal water loss (TEWL) from 13 to 24 g/m(2)/h. Hyperplasia and inflammation, but not loss of TJ, were also observed in UVB-treated skin. UVA+UVB- and UVA-irradiated skin demonstrated similar changes in histology and biomarkers. UVA+UVB or UVA exposure increased hydroquinone flux five-fold. A negligible alteration of hydroquinone permeation was shown with UVB exposure. Hydroquinone exhibited a lower penetration through senescent skin than young skin. Both UVA and UVB produced enhancement of oxybenzone flux and skin uptake. However, the amount of increase was less than that of hydroquinone delivery. Photoaging did not augment skin absorption of sunscreens with higher lipophilicity, including avobenzone and ZnO. Exposure to UVA generally increased follicular entrance of these permeants, which showed two- to three-fold greater follicular uptake compared to the untreated group. Photoaging had less impact on drug/sunscreen absorption with more lipophilic permeants. Percutaneous absorption did not increase in skin subjected to both intrinsic and extrinsic aging.

The objective evaluation of the severity of psoriatic scales with desquamation collecting tapes and image analysis

BACKGROUND

Assessment of psoriatic scales is important to determine the severity of psoriasis. However, there are very limited numbers of objective, quantitative and observer-independent tools for measuring the severity of psoriasis.

OBJECTIVE

To determine whether the bioengineering parameters of the psoriatic scale can be used to assess the severity of psoriasis instead of the psoriatic severity index of scales (PSIs) score.

METHODS

Thirty-four patients with psoriasis were included. A representative lesion from each patient was selected and bioengineering parameters were measured using the Corneofix(®). Simultaneously, the severity of the scales was assessed by the PSIs score using clinical photographs of the lesions. In addition, skin color and elasticity parameters were also measured using the Colorimeter(®), the Mexameter(®) and the Cutometer(®).

RESULTS

Statistical differences in the scale parameters were observed between the PSIs 2 and 3 scores. Among the scale parameters, the percent area and area in μm(2) were negatively correlated with the PSIs score. In addition, the Colorimeter(®) a, b parameters and the Cutometer(®) R9 parameters were significantly correlated with the PSIs score.

CONCLUSIONS

The results of this study showed that the severity of psoriatic scales could be measured objectively using the Corneofix(®).

[Molecular basis of photoaging]

As a result of the increase in life expectancy, the study of the organic process of aging has been stimulated. Skin ageing, which reflects the signs of time, is a time-dependent process of progressive deterioration that can be intensified by sun exposure, which is known as photoaging. The damage of radiation on various cell structures and on the skin results in molecular and morphological changes to these components. Many research studies are performed to try to minimize the effects of photoaging; however, the main strategy to manage it is still prevention, which will only be achieved once we learn about the mechanisms involved in the process.

LED photoprevention: reduced MED response following multiple LED exposures

BACKGROUND AND OBJECTIVES

As photoprotection with traditional sunscreen presents some limitations, the use of non-traditional treatments to increase skin resistance to ultraviolet (UV) induced damage would prove particularly appealing. The purpose of this pilot study was to test the potential of non-thermal pulsed light-emitting diode (LED) treatments (660 nm) prior to UV exposure in the induction of a state of cellular resistance against UV-induced erythema.

STUDY DESIGN/MATERIALS AND METHODS

Thirteen healthy subjects and two patients with polymorphous light eruption (PLE) were exposed to 5, 6, or 10 LED treatments (660 nm) on an EXPERIMENTAL anterior thigh region. Individual baseline minimal erythema doses (MED) were then determined. UV radiation was thereafter performed on the LED EXPERIMENTAL and CONTROL anterior thigh areas. Finally, 24 hours post-UV irradiation, LED pre-treated MED responses were compared to the non-treated sites.

RESULTS

Reduction of erythema was considered significant when erythema was reduced by >50% on the LED-treated side as opposed to CONTROL side. A significant LED treatment reduction in UV-B induced erythema reaction was observed in at least one occasion in 85% of subjects, including patients suffering from PLE. Moreover, there was evidence of a dose-related pattern in results. Finally, a sun protection factor SPF-15-like effect and a reduction in post-inflammatory hyperpigmentation were observed on the LED pre-treated side.

CONCLUSIONS

Results suggest that LED based therapy prior to UV exposure provided significant protection against UV-B induced erythema. The induction of cellular resistance to UV insults may possibly be explained by the induction of a state a natural resistance to the skin via specific cell signaling pathways and without the drawbacks and limitations of traditional sunscreens. These results represent an encouraging step towards expanding the potential applications of LED therapy and could be useful in the treatment of patients with anomalous reactions to sunlight.

The characteristics of aromatase deficient hairless mice indicate important roles of extragonadal estrogen in the skin

The roles of extragonadal estrogen in the skin are poorly understood, due to the lack of proper animal models. We examined the skin phenotypes of aromatase-knockout hairless (ArKO) mice and wild-type hairless (WT) mice, both of which were obtained through crossbreeding of Ar+/- mice and hairless mice. Differences in the skins of ArKO and WT mice were compared with those of ovariectomized (OVX) and control (Sham) mice. A difference was observed in the skin tone of ArKO mice, which is pale white and differs from the pinkish tone of all other mice. However, both ArKO and OVX mice similarly exhibited deteriorations of skin properties as compared to their respective controls. Furthermore, all the deteriorations were similarly amplified by chronic UVB irradiation in both ArKO and OVX mice as compared to their respective controls. The unique skin phenotype of ArKO mice was observed in sunburn reactions. Specifically, skins of ArKO mice showed no reaction after an acute UVB irradiation at dose intensities caused sunburn in others. However, follow-up observation found delayed reactions associated with brownish skin color and swelling only in ArKO mice, thereby suggesting that the role of extragonadal estrogen may be connected with the protective reactions of skin.

New strategies of photoprotection

Adequate photoprotection is essential to control UV-related disorders, including sunburn, photoaging and photocarcinogenisis. Sun avoidance, protection of skin with clothing, and sunscreens are presently the best way of photoprotection, assuming that they are used properly. However, new strategies, which are based on or make use of the endogenous protective response to UV light, may further improve currently used photoprotective means. The addition of repair enzymes and/or antioxidants has a positive effect on skin's recovery from UV-induced DNA-damage. Several botanical agents, mainly vitamins and polyphenols, have shown to influence signal transduction pathways leading to photoprotective effects. Also stimulation of endogenous UV-response pathways via irradiation with a low UV dose or via simulation of UV-induced DNA-damage results in photoprotective effects. Future research in this field and combination of different photoprotective strategies will hopefully lead to improved photoprotection.