UV-induced Skin Photoaging Research Articles

Comprehensive analysis of Hibisci mutabilis Folium extract's mechanisms in alleviating UV-induced skin photoaging through enhanced network pharmacology and experimental validation.

Skin photoaging induced by ultraviolet A (UVA) and ultraviolet B (UVB) radiation manifests as skin roughness, desquamation, pigmentation, and wrinkle formation. Current treatments, such as sunscreen, hormones, and antioxidants, have limitations and side effects. Traditional Chinese Medicine Hibisci Mutabilis Folium (HMF), or Mu-Fu-Rong-Ye in Chinese name, refers to the dried leaves of the plant Hibiscus mutabilis L., which belongs to the Malvaceae family. It has been used traditionally to treat acute mastitis, parotitis, neurodermatitis, burns. The reported activities of HMF include anti-inflammatory and anti-oxidant effects. However, the therapeutic potential of HMF in preventing and treating UV-induced skin photoaging remains unexplored. This study aimed to investigate the protective effects of HMF extract (EHMF) against UV-induced skin photoaging and the underlying mechanisms of action, by using network pharmacology and experimental verification. Network pharmacology was employed to identify the effective chemical components of EHMF. Potential targets were identified via PPI network analysis. Representative compounds were characterized using UPLC-MS/MS. In vitro validation involved assessing HaCaT cell viability, observing live/dead cell staining through fluorescence microscopy, and measuring inflammatory factors using ELISA. For in vivo validation, a UV-induced skin photoaging mice model was treated transdermally with EHMF or Methotrexate daily for 7 days. Dermatitis severity, skin morphology, and collagen fiber pathology were evaluated. Inflammatory cytokine and protein expression in dorsal skin lesions was confirmed using Elisa Kits, Western blot and immunohistochemistry. A total of 22 active ingredients of EHMF were identified. GO enrichment and KEGG pathway analyses revealed a focus on inflammatory signaling pathways. In vitro experiments showed that EHMF significantly reduced UV-induced inflammatory factors in HaCaT cells and improved cell survival rates. In vivo, EHMF alleviated back skin lesions in UV-exposed mice, reducing epidermal and dermal thickening and pathological inflammatory cell infiltration. It also decreased abnormal MMP-9 expression and collagen fiber proliferation, along with levels of inflammatory factors like TNF-α, IL-6, IL-17, and EGFR. Western blot and immunohistochemistry results indicated that the over-activation of the AKT-STAT3 signaling pathway was inhibited. EHMF effectively reduced UV-induced skin damage, inflammation, and wrinkles, providing strong support for its clinical application as a dermatological agent.

Oral Yak Whey Protein Can Alleviate UV-Induced Skin Photoaging and Modulate Gut Microbiota Composition.

Excessive UV exposure can lead to skin roughness, wrinkles, pigmentation, and reduced elasticity, with severe cases potentially causing skin cancer. Nowadays, various anti-photoaging strategies have been developed to maintain skin health. Among them, dietary supplements with anti-photoaging properties are gaining increasing attention. Yak whey protein (YWP) possesses multiple benefits, including anti-inflammatory, antioxidant, and immune-boosting properties, effectively protecting the skin. This study used a mixed UVA and UVB light source to irradiate a nude mouse model, exploring the advantages of YWP in anti-photoaging and regulating gut microbiota. The results indicated that YWP alleviated UV-induced skin damage, wrinkles, dryness, and reduced elasticity by inhibiting oxidative stress, inflammatory factors (IL-1α, IL-6, and TNF-α), and matrix metalloproteinases (MMP-1, MMP-3, and MMP-12), thereby increasing the levels of elastin, type I collagen, and type III collagen in the extracellular matrix (ECM). Additionally, YWP significantly improved the abundance of Firmicutes and Bacteroidota in the gut microbiota of mice, promoting the growth of beneficial bacteria such as Lachnospiraceae_NK4A136_group, Ruminococcus_torques_group, and Clostridia_UCG_014, mitigating the dysbiosis caused by photoaging. These findings underscore the potential of YWP in anti-photoaging and gut microbiota improvement, highlighting it as a promising functional food for enhancing skin and gut health.

The Protective Effects of Silkworm (Bombyx mori) Pupae Peptides on UV-Induced Skin Photoaging in Mice.

Silkworm (Bombyx mori) pupae are popular edible insects with high nutritional and therapeutic value. Currently, there is growing interest in the comprehensive application of silkworm pupae. In this study, peptides that exhibited anti-photoaging activity were obtained from silkworm pupae protein, aiming to investigate the protective effects and potential mechanisms of silkworm pupae peptides (SPPs) on skin photoaging. The results showed that SPPs were composed of 900 short peptides and could effectively alleviate skin photoaging progression. They significantly eliminated excessive production of ROS and MDA; meanwhile, they also renovated the antioxidant enzyme activities. The biomarkers related to collagen synthesis and degradation, including hydroxyproline, interstitial collagenase, and gelatinase, demonstrated that SPPs could suppress collagen degradation. Histopathological results showed that SPPs could reduce the inflammatory infiltrate and the thickness of the dermis and epidermis, as well as increase the collagen bundles and muscle fibers. The histopathological and biochemical results confirmed that SPPs could alleviate photoaging by inhibiting abnormal skin changes, reducing oxidative stress, and immune suppression. Overall, these data prove the protective effects of SPPs against the photoaging process, suggesting their potential as an active ingredient in skin photoaging prevention and therapy.

Myconoside and Calceolarioside E Restrain UV-Induced Skin Photoaging by Activating NRF2-Mediated Defense Mechanisms.

Chronic and excessive ultraviolet (UVA/UVB) irradiation exposure is known as a major contributor to premature skin aging, which leads to excessive reactive oxygen species generation, disturbed extracellular matrix homeostasis, DNA damage, and chronic inflammation. Sunscreen products are the major preventive option against UVR-induced photodamage, mostly counteracting the acute skin effects and only mildly counteracting accelerated aging. Therefore, novel anti-photoaging and photopreventive compounds are a subject of increased scientific interest. Our previous investigations revealed that the endemic plant Haberlea rhodopensis Friv. (HRE) activates the antioxidant defense through an NRF2-mediated mechanism in neutrophiles. In the present study, we aimed to investigate the photoprotective potential of HRE and two of its specialized compounds-the phenylethanoid glycosides myconoside (MYC) and calceolarioside E (CAL)-in UVA/UVB-stimulated human keratinocytes in an in vitro model of photoaging. The obtained data demonstrated that the application of HRE, MYC, and CAL significantly reduced intracellular ROS formation in UVR-exposed HaCaT cells. The NRF2/PGC-1α and TGF-1β/Smad/Wnt signaling pathways were pointed out as having a critical role in the observed CAL- and MYC-induced photoprotective effect. Collectively, CAL is worth further evaluation as a potent natural NRF2 activator and a promising photoprotective agent that leads to the prevention of UVA/UVB-induced premature skin aging.

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.

Protective role of melatonin in ultraviolet radiation- induced oxidative stress in human skin photoaging

The ultraviolet radiation of the sun that reaches the earth is made up of ultraviolet A (95%) and ultraviolet B (5%). Exposure to ultraviolet radiation (UVR) is the main factor in photoaging. Chronic exposure to sunlight acts as an environmental stressor, leading to oxidative damage or stress. Oxidative damage stimulates the accumulation of free radicals, such as reactive oxygen species (ROS) or reactive nitrogen species (RNS) that are responsible for premature skin aging. Photoaged skin is characterized externally by irregular pigmentation, wrinkles, and reduced skin elasticity, and internally by the breakdown of dermal collagen and elastin. Free radicals can be scavenged and the skin can be protected from further oxidative damage by antioxidants. Melatonin is a hormone produced mainly by the pineal gland, as well as many other organs, including the skin. One of the functions of melatonin is exerted by the antioxidative melatoninergic system to prevent ultraviolet (UV)-induced skin photoaging. The aim of this review was to study the protective effect of melatonin on skin photoaging resulting from UVR exposure. The references were tracked using various databases, such as Google Scholar and PubMed with regard to publications in English for the last 5 years (2019-2023). Melatonin inhibits UVR-induced aging in multiple ways, such as protecting skin cells, binding free radicals, accelerating the activity of antioxidant enzymes, preventing increased mitochondrial membrane permeability, and assisting electron transport efficiency in the mitochondrial respiratory chain. Exogenous application of melatonin is usually by the oral route, but for localized effects on the skin, topical administration is recommended, with consideration of preparations with a better half-life and bioavailability. Understanding the protective antioxidant function of melatonin in UV-induced skin photoaging helps to optimize its application. The protective properties of melatonin against UVR-oxidative stress-induced photoaging will be further explored in this review.

Taif Rose Oil Ameliorates UVB-Induced Oxidative Damage and Skin Photoaging in Rats via Modulation of MAPK and MMP Signaling Pathways.

Short-wave UVB (ultraviolet B) causes rapid oxidative damage to the skin. Rose water is obtained mainly from the petals of Rosa damascena Mill. (Rosaceae) and used traditionally to hydrate dry skin and reduce signs of aging. This work aimed at evaluating the possible protective potential of the prepared eco-friendly Taif rose oil nanoemulsion (ROSE-NANO) against UVB-induced photoaging in adult male Wistar rats. Taif rose oil (ROSE) was obtained from R. damascene by classical steam distillation and formulated in emulgel (100 mg/g). In addition, the oil was formulated in ROSE-NANO-loaded emulgel (50 and 100 mg/g) to enhance the effect of ROSE. All prepared formulas were tested topically for their potential protective effect in UV-induced skin photoaging. The obtained results demonstrated that application of ROSE-NANO-loaded emulgel resulted in superior antiaging potency over ROSE emulgel based on histological studies as well as biochemical evaluations via amendment in CAT and SOD activities, decreasing the concentration of the inflammatory markers and preventing collagen fragmentation through reduction of MMP-9 content in fibroblasts. Moreover, a significant decrease in mRNA expression of NF-KB, JNK, ERK1/2, and p38 MAPK genes was observed. In conclusion, the current study provides scientific evidence for the traditional use of rose oil in skin aging. Moreover, the NANO formula showed promising efficacy as a skin photoprotector against UV-induced oxidative damage and skin aging.

Mesenchymal stem cell-derived exosomes and skin photoaging: From basic research to practical application.

Skin photoaging is a condition caused by long-term exposure to ultraviolet irradiation, resulting in a variety of changes in the skin, such as capillary dilation, increased or absent pigmentation, dryness, sagging, and wrinkles. Stem cells possess a remarkable antioxidant capacity and the ability to proliferate, differentiate, and migrate, and their main mode of action is through paracrine secretion, with exosomes being the primary form of secretion. Stem cell-derived exosomes contain a variety of growth factors and cytokines and may have great potential to promote skin repair and delay skin ageing. This review focuses on the mechanisms of UV-induced skin photoaging, the research progress of stem cell exosomes against skin photoaging, emerging application approaches and limitations in the application of exosome therapy. Exosomes derived from various stem cells have the potential to prevent skin photoaging. The combination with novel materials may be a key step for their practical application, which could be an important direction for future basic research and practical applications.

ErZhiFormula prevents UV-induced skin photoaging by Nrf2/HO-1/NQO1 signaling: An in vitro and in vivo studies.

ErZhiFormula (EZF) is a classical traditional Chinese medicinal formulation. It can be used to treat liver and kidney yin deficiency, dizziness, lumbar debility, insomnia, nocturnal emission, lower extremity weakness, and other aging-related diseases. However, the protective effect of EZF in skin photoaging and its potential mechanism has not been clarified. This study aims to explore the role of EZF in the skin photoaging mechanism induced by UV radiation. Ultra Performance Liquid Chromatography (UPLC) was used to identify the fingerprint of EZF. The mice were irradiated with UVA and UVB to establish the photoaging model in vivo. Human immortalized keratinocytes (HaCaT) were irradiated with UVB to establish the photoaging model in vitro. The activity of cells was detected by CCK-8 and LDH kits, the level of reactive oxygen species was detected by DCF fluorescent probe, and the apoptosis was detected by PE annexin V and 7-Amino-Actinomycin (7-AAD) staining. Comet assay was used to detect cell DNA damage. The antioxidant enzyme levels in cell and mouse serum were detected by antioxidant kit, and Western blot was used to detect protein expression. We found that EZF contain many active ingredients, including salidroside, specnuezhenide, isoquercitrin, etc. EZF can improve the photoaging of HaCaT cells and mouse skin caused by UV radiation. The results of animal experiments are consistent with those of cell experiments. Combined with Western blot analysis, we found that EZF finally played an anti-skin photoaging role by regulating the Nrf2/HO-1/NQO1 pathway. EZF can protect skin from UV-induced photoaging by regulating the Nrf2/HO-1/NQO1 signal pathway. EZF may become a traditional Chinese medicine with the potential to prevent skin photoaging.

Interaction of TAGLN and USP1 promotes ZEB1 ubiquitination degradation in UV-induced skin photoaging

BackgroundUltraviolet A (UVA) irradiation can lead to skin damage and premature skin aging known as photoaging. This work found that UVA irradiation caused an imbalance between dermal matrix synthesis and degradation through the aberrant upregulation of transgelin (TAGLN) and studied the underlying molecular mechanism.ResultsCo-immunoprecipitation and proximal ligation assay results showed that TAGLN can interact with USP1. USP1 can be retained in the cytoplasm by TAGLN in UVA-induced cells, which inhibits the interaction between USP1/zinc finger E-box binding homeobox 1 (ZEB1), promote the ubiquitination degradation of ZEB1, and lead to photoaging. TAGLN knockdown can release USP1 retention and help human skin fibroblasts (HSFs) resist UVA-induced damage. The interactive interface inhibitors of TAGLN/USP1 were screened via virtual docking to search for small molecules that inhibit photoaging. Zerumbone (Zer), a natural product isolated from Zingiber zerumbet (L.) Smith, was screened out. Zer can competitively bind TAGLN to reduce the retention of USP1 in the cytoplasm and the degradation of ZEB1 ubiquitination in UV-induced HSFs. The poor solubility and permeability of Zer can be improved by preparing it as a nanoemulsion, which can effectively prevent skin photoaging caused by UVA in wild-type (WT) mice. Zer cannot effectively resist the photoaging caused by UVA in Tagln−/− mice because of target loss.ConclusionsThe present results showed that the interaction of TAGLN and USP1 can promote ZEB1 ubiquitination degradation in UV-induced skin photoaging, and Zer can be used as an interactive interface inhibitor of TAGLN/USP1 to prevent photoaging.

Lactic acid bacteria and their lysate ameliorate skin inflammation in a UVB irradiation-induced skin photoaging mouse model

Skin photoaging is premature skin aging caused by over exposure to ultraviolet (UV) radiation. Photoaged skin is characterized by epidermal thickening, dryness, deep wrinkles, loss of elasticity, delayed wound healing and susceptibility to cancer and closely related to skin inflammation. Meanwhile, it had been reported that lactic acid bacteria (LAB) lysate has lots of beneficial components such as fatty acid, vitamin B, and amino acids, and LAB has the anti-inflammatory effects and the potentials as therapeutics for many chronic inflammatory diseases. Because skin photoaging is recovered by reducing inflammation, co-treatment of LAB and their lysate may alleviate the skin conditions caused by UV-induced skin photoaging via the anti-inflammatory effects. Therefore, the aim of this study is to find out whether co-treatment of LAB and their lysate has beneficial effects on skin conditions and ameliorates skin photoaging. LAB and their lysate were treated in vitro and in vivo. LAB lysate decreased the expression levels of pro-inflammatory cytokines including TNF-α and other inflammation-related biomarkers such as cyclooxygenase 2 (COX-2) and toll-like receptor 4 (TLR4) significantly in HaCaT, the human keratinocyte cell line. LAB and their lysate was evaluated in UVB-induced skin photoaged HR-1 mice model, and it decreased the pro-inflammatory cytokines including TNF-α in serum. LAB and their lysate also decreased pro-inflammatory cytokines in skin, colon, and spleen. Moreover, LAB and their lysate changed the composition of fecal microbiome and short chain fatty acids in mice. In conclusion, the topical treatment of lactic acid bacteria and their lysate may have a potential to ameliorate skin photoaging by reducing inflammation. This work was supported by Korea Testing Laboratory This is the full abstract presented at the American Physiology Summit 2023 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Potential Extracts of Melastomataceae Species from Mount Merapi National Park as Sunprotection Material with Antioxidation and Antiglycation Activities

Ethanol extracts from the leaves of Clidemia hirta (L.) D. Don., and Melastoma affine D. Don., growing in Mount Merapi National Park, Indonesia, had high  antioxidant activity similar to ascorbic acid. Natural substances with high  antioxidant activity potentially inhibit UV-induced skin photoaging. This study  aimed to investigate the sun protection factor (SPF) and antiglycation activity of  C. hirta and M. affine ethanol extracts to identify and obtain candidate  hotoprotective ingredients for sunscreen products. Proximate analysis of extract  simplicial was performed for standardization, and their secondary  metabolites quantified to understand their bioactivities. Flavonoids, alkaloids,  and saponins were quantified using the aluminum chloride, bromocresol green,  and vanillin-sulfuric acid methods, respectively. Phenolic compounds  and tannins were quantified using the Folin-Ciocalteu method. The C. hirta  extract showed a higher SPF value in UV spectrophotometry, and antiglycation  activity through bovine serum albumin-glucose (BSAglucose) method, than the  M. affine extract. An antioxidant assay using the 2,2-diphenyl-1- picrylhydrazyl  (DPPH) radical scavenging method confirmed that the C. hirta and M. affine extracts were more potent and had slightly lower antioxidant activity,  respectively, than ascorbic acid. The high bioactivity of C. hirta extract was likely  due to phenolic compounds, flavonoids, and tannins, because these metabolites  were more abundant in C. hirta extract than in M. affine extract.  These results indicated that the ethanol extract of C. hirta leaves has the  potential to be developed as an ingredient of sunscreen products for skin  photoprotection.&nbsp

The combined effect of commercial tilapia collagen peptides and antioxidants against UV-induced skin photoaging in mice.

Chronic over-exposure to UV radiation leads to the damage of skin tissue. The aim of this study was to investigate the effects of collagen peptide (CP) and antioxidant (astaxanthin, vitamin C (Vc), and vitamin E (Ve)) combinations on skin photoaging. Forty male UV-induced BALB/c mice were randomized and fed saline or CP and antioxidants for 7 weeks using gavage feeding. The results showed that oral administration of CP, CP combined with Vc and Ve (VCE) or Haematococcus pluvialis extract (HPE) significantly (P < 0.05) reduced a* of mouse skin and increased the content of Hyp and type I collagen to varying degrees, thereby improving skin integrity. Furthermore, the combination of CP, HPE, and VCE showed increased upregulation of antioxidant enzyme expression, reduced serum ROS, and decreased inhibition of metalloproteinase expression compared to the other treatment groups. Thus, this combination showed better effects in inhibiting collagen degradation and maintaining the redox balance. The Nrf2/ARE and TGF-β/Smad transcription systems are likely involved in these effects. Therefore, the results suggest that a diet containing CP, astaxanthin, and vitamins might be recommended to improve skin health and appearance.

Explore the multitarget mechanism of tetrahydrocurcumin preventing on UV-induced photoaging mouse skin

UV induced photoaging is the main external factor of skin aging. In this study, we tested the protective effects of tetrahydrocurcumin on UV-induced skin photoaging of KM mice and researched the multi-target mechanism through RNA sequencing technology. Mouse experiments show that tetrahydrocurcumin strongly changed in skin appearance, epidermal thickness, and wrinkle-related parameters in UV-irradiated mice. RNA-seq result show that we found 29 differentially expressed mRNA transcripts in UV mice relative to Ctrl rats (18 up-regulated and 11 down-regulated) and 7 significantly dysregulated mRNAs were obtained in the THC group compared to the UV group (1 up-regulated and 6 down-regulated), respectively. Spink7, Edn3, Stab2 may be the key target genes of tetrahydrocurcumin in preventing aging. Bioinformatics analysis shows that the response to muscle contraction and melanin biosynthetic GO term and Inflammation related pathway such as PPAR, MAPK would involve in effects of tetrahydrocurcumin. The results of this study indicated that tetrahydrocurcumin can improve the appearance through anti-inflammatory, improving extracellular matrix and inhibiting melanin production. It could be suggested as a protective measure in the prevention of UV-induced photoaging.

Corylin from Psoralea fructus (Psoralea corylifolia L.) protects against UV-induced skin aging by activating Nrf2 defense mechanisms.

Oxidative stress damage can lead to premature skin aging or age-related skin disorders. Therefore, strategies to improve oxidative stress-induced aging are needed to protect the skin and to treat skin diseases. This study aimed to determine whether the flavonoid corylin derived from Psoralea corylifolia can prevent UV-induced skin aging and if so, to explore the potential molecular mechanisms. We found that corylin potently blocked UV-induced skin photoaging in mice by reducing oxidative stress and increasing the nuclear expression of nuclear factor-erythroid factor 2-related factor 2 Nrf2. We also found that corylin stimulated Nrf2 translocation into the nucleus and increased the delivery of its target antioxidant genes together with Kelch-like ECH-associated protein 1 (Keap1) to dissociate Nrf2. These findings indicate that corylin could prevent skin aging by inhibiting oxidative stress via Keap1-Nrf2 in mouse cells. Thus, Nrf2 activation might be a therapeutic target for preventing skin aging or skin diseases caused by aging. Our findings also provided evidence that warrants the further investigation of plant ingredients to facilitate the discovery of novel therapies targeting skin aging.

Coriander (Coriandrum sativum L.) essential oil and oil-loaded nano-formulations as an anti-aging potentiality via TGF\u03b2/SMAD pathway

Aging has become a concern for many people, especially women. Given that high-quality anti-aging products are of high cost; it has imperative to search for other economical sources. Essential oils are frequently used in cosmetics products due to a wide range of biological activities as well as their pleasant odor. The current study aimed to investigate the biochemical effect of the cosmetic potential of selected Apiaceous essential oils, traditionally used for skincare, by evaluating their anti-wrinkle activity. It is worth noting that, coriander essential oil showed the highest collagenase, elastase, tyrosinase, and hyaluronidase inhibitory activities compared to other Apiaceous oils (fennel, anise, and cumin). GC–MS proved that coriander essential oil showed a very high level of oxygenated monoterpenes, with linalool (81.29%) as the most abundant constituent. Intriguingly, coriander oil cream and Coriander Essential Oil-loaded Lipid Nanoparticles (CEOLNs) formulations attenuated in vivo UV-induced skin photoaging that was manifested by significantly decreased MDA, COX-2, PGE-2, MMP-1, JNK, and AP-1 levels. Moreover, these pharmaceutical dosage forms significantly increased skin collagen content compared to UV-injured group. Also, coriander essential oil significantly increased TGFβ, TGFβII, and SMAD3 protein expression levels compared to UV-injured group. In conclusion, the pharmaceutical dosage forms of coriander oil possess anti-wrinkle activities that could have an auspicious role in amending extrinsic aging.

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.

Attenuation of UV-induced skin photoaging in rats by walnut protein hydrolysates is linked to the modulation of MAPK/AP-1 and TGF-β/Smad signaling pathways

There is growing evidence that prevention of skin photoaging by oral administration of food-derived proteins hydrolysates is intricately linked to its alleviation against oxidative stress through modulation of the signaling pathway. Previously, walnut protein hydrolysates (WPHs) were prepared by enzymatic hydrolysis by our group and exhibited excellent anti-photoaging effect through regulation of extracellular matrix metabolism and the NF-κB signaling pathway. However, its response to oxidative stress and cascade mechanism remain unknown. In the present study, Sprague-Dawley rats were exposed periodically to UV irradiation and orally administered with WPHs to further examine the effects of WPHs on the redox state, MAPK/AP-1 and TGF-β/Smad signaling pathways, type I procollagen synthesis, and histopathological impairments in photoaging skin. Intervention with WPHs for 18 weeks significantly alleviated the photoaging morphology, enhanced the antioxidant components, and downregulated the phosphorylation levels of extracellular signal-regulated kinase (ERK) and C-Jun N-terminal kinase (JNK and p38 proteins) in photoaging tissues, while significant alterations on the gene expression levels of ERK, JNK and p38 were not observed. Meanwhile, WPHs significantly activated the TGF-β/Smad signaling pathway and type I procollagen production. Furthermore, histopathological analysis illustrated that WPHs predominately attenuated epidermal hyperplasia, reduced inflammatory filtration, and promoted the deposition of collagen fibers in photoaging skin. Altogether, the underlying mechanism of WPHs attenuating skin photoaging might lie in the synergistic modulation by increasing the antioxidant capacity, modulating the MAPK/AP-1/MMP-1 and TGF-β/Smad signaling pathways, stimulating the synthesis of type I procollagen, and restoring the impaired architecture structure. Our findings suggest that WPHs are promising agents for preventing skin photoaging.

Cathelicidin-NV from Nanorana ventripunctata effectively protects HaCaT cells, ameliorating ultraviolet B-induced skin photoaging

Cathelicidins are diverse effector molecules in the vertebrate immune system and are related to immune regulation, inflammatory response, wound healing, and blood vessel formation. However, little is known about their free radical scavenging ability, especially in vivo. In this study, a cathelicidin molecule (cathelicidin-NV, ARGKKECKDDRCRLLMKRGSFSYV) previously identified from the spot-bellied plateau frog (Nanorana ventripunctata) (Anura, Dicroglossidae, Dicroglossinae) by us was shown to alleviate ultraviolet B (UVB)-induced skin photoaging in mice. Cathelicidin-NV effectively suppressed cytotoxicity, DNA fragmentation, apoptosis and reduced the protein expression levels of JNK, c-Jun, and MMP-1, which are involved in the regulation of collagen degradation in HaCaT cells induced by UVB irradiation. Furthermore, cathelicidin-NV also scavenged UVB-induced intracellular reactive oxygen species (ROS). Taken together, cathelicidin-NV directly scavenged excessive intracellular ROS to protect HaCaT cells, and subsequently alleviated UVB-induced skin photoaging. This study extends reports on the antioxidant function of the cathelicidin family. In addition, the properties of cathelicidin-NV make it an excellent candidate for the prevention and treatment of UV-induced skin photoaging.

Protective effects of fucoidan purified from Undaria pinnatifida against UV-irradiated skin photoaging.

BackgroundExposure to ultraviolet (UV) radiation (UVB and UVA) is the most well-known extrinsic factor that induces skin aging. Fucoidan has been shown to possess antiphotoaging effects against UV irradiation and can be used as an ingredient in the pharmaceutical industry. The present study evaluated the photoprotective effect of fucoidan purified from Undaria pinnatifida (UPF) on UV-induced skin photoaging and explored its potential molecular mechanism.MethodsTo evaluate the effect of UPF on UV-induced skin aging, HaCaT cells and HFF-1 cells were pretreated with or without UPF and then exposed to UVB and UVA radiation, respectively, and the levels of cellular senescence, reactive oxygen species (ROS) production and mitochondrial dysfunction were evaluated. The mitochondrial ROS (mROS) was stained through MitoSOX, and the confocal microscope was used to capture the images. For further exploration of AMPK/SIRT-1/PGC-1α signaling, western blot was employed.ResultsThe results demonstrated that pretreatment of HaCaT and HFF-1 cells with UPF ameliorated cellular senescence, ROS and mROS overproduction, and mitochondrial dysfunction caused by UV exposure. This research also revealed that UPF could activate the AMPK/SIRT-1/PGC-1α signaling pathway to promote mitochondrial biogenesis.ConclusionsUPF can ameliorate UV-induced skin photoaging through inhibition of ROS production via the alleviation of mitochondrial dysfunction by regulating the SIRT-1/PGC-1α signaling pathway.