Unraveling UVB effects: Catalase activity and molecular alterations in the stratum corneum.

AIM: Ultraviolet B (UVB) radiation can compromise the functionality of the skin barrier through various mechanisms. We hypothesize that UVB induce photochemical alterations in the components of the outermost layer of the skin, known as the stratum corneum (SC), and modulate its antioxidative defense mechanisms. Catalase is a well-known antioxidative enzyme found in the SC where it acts to scavenge reactive oxygen species. However, a detailed characterization of acute UVB exposure on the activity of native catalase in the SC is lacking. Moreover, the effects of UVB irradiation on the molecular dynamics and organization of the SC keratin and lipid components remain unclear. Thus, the aim of this work is to characterize consequences of UVB exposure on the structural and antioxidative properties of catalase, as well as on the molecular and global properties of the SC matrix surrounding the enzyme. EXPERIMENTS: The effect of UVB irradiation on the catalase function is investigated by chronoamperometry with a skin covered oxygen electrode, which probes the activity of native catalase in the SC matrix. Circular dichroism is used to explore changes of the catalase secondary structure, and gel electrophoresis is used to detect fragmentation of the enzyme following the UVB exposure. UVB induced alterations of the SC molecular dynamics and structural features of the SC barrier, as well as its water sorption behavior, are investigated by a complementary set of techniques, including natural abundance 13C polarization transfer solid-state NMR, wide-angle X-ray diffraction, Fourier transform infrared (FTIR) spectroscopy, and dynamic vapor sorption microbalance. FINDINGS: The findings show that UVB exposure impairs the antioxidative function of catalase by deactivating both native catalase in the SC matrix and lyophilized catalase. However, UVB radiation does not alter the secondary structure of the catalase nor induce any observable enzyme fragmentation, which otherwise could explain deactivation of its function. NMR measurements on SC samples show a subtle increase in the molecular mobility of the terminal segments of the SC lipids, accompanied by a decrease in the mobility of lipid chain trans-gauche conformers after high doses of UVB exposure. At the same time, the NMR data suggest increased rigidity of the polypeptide backbone of the keratin filaments, while the molecular mobility of amino acid residues in random coil domains of keratin remain unaffected by UVB irradiation. The FTIR data show a consistent decrease in absorbance associated with lipid bond vibrations, relative to the main protein bands. Collectively, the NMR and FTIR data suggest a small modification in the composition of fluid and solid phases of the SC lipid and protein components after UVB exposure, unrelated to the hydration capacity of the SC tissue. To conclude, UVB deactivation of catalase is anticipated to elevate oxidative stress of the SC, which, when coupled with subtle changes in the molecular characteristics of the SC, may compromise the overall skin health and elevate the likelihood of developing skin disorders.

Role of epigenetics in the regulation of skin aging and geroprotective intervention: A new sight.

Multiple epigenetic factors play a regulatory role in maintaining the homeostasis of cutaneous components and are implicated in the aging process of the skin. They have been associated with the activation of the senescence program, which is the primary contributor to age-related decline in the skin. Senescent species drive a series of interconnected processes that impact the immediate surroundings, leading to structural changes, diminished functionality, and heightened vulnerability to infections. Geroprotective medicines that may restore the epigenetic balance represent valid therapeutic alliances against skin aging. Most of them are well-known Western medications such as metformin, nicotinamide adenine dinucleotide (NAD+), rapamycin, and histone deacetylase inhibitors, while others belong to Traditional Chinese Medicine (TCM) remedies for which the scientific literature provides limited information. With the help of the Geroprotectors.org database and a comprehensive analysis of the referenced literature, we have compiled data on compounds and formulae that have shown potential in preventing skin aging and have been identified as epigenetic modulators.

Platelet rich fibrin and simvastatin-loaded pectin-based 3D printed-electrospun bilayer scaffold for skin tissue regeneration.

Designing multifunctional wound dressings is a prerequisite to prevent infection and stimulate healing. In this study, a bilayer scaffold (BS) with a top layer (TL) comprising 3D printed pectin/polyacrylic acid/platelet rich fibrin hydrogel (Pec/PAA/PRF) and a bottom nanofibrous layer (NL) containing Pec/PAA/simvastatin (SIM) was produced. The biodegradable and biocompatible polymers Pec and PAA were cross-linked to form hydrogels via Ca2+ activation through galacturonate linkage and chelation, respectively. PRF as an autologous growth factor (GF) source and SIM together augmented angiogenesis and neovascularization. Because of 3D printing, the BS possessed a uniform distribution of PRF in TL and an average fiber diameter of 96.71 ± 18.14 nm was obtained in NL. The Young's modulus of BS was recorded as 6.02 ± 0.31 MPa and its elongation at break was measured as 30.16 ± 2.70 %. The wound dressing gradually released growth factors over 7 days of investigation. Furthermore, the BS significantly outperformed other groups in increasing cell viability and in vivo wound closure rate (95.80 ± 3.47 % after 14 days). Wounds covered with BS healed faster with more collagen deposition and re-epithelialization. The results demonstrate that the BS can be a potential remedy for skin tissue regeneration.

The Potential of Twendee X® as a Safe Antioxidant Treatment for Systemic Sclerosis.

Systemic sclerosis (SSc) is an autoimmune disease characterized by systemic skin hardening, which combines Raynaud's phenomenon and other vascular disorders, skin and internal organ fibrosis, immune disorders, and a variety of other abnormalities. Symptoms vary widely among individuals, and personalized treatment is sought for each patient. Since there is no fundamental cure for SSc, it is designated as an intractable disease with patients receiving government subsidies for medical expenses in Japan. Oxidative stress (OS) has been reported to play an important role in the cause and symptoms of SSc. HOCl-induced SSc mouse models are known to exhibit skin and visceral fibrosis, vascular damage, and autoimmune-like symptoms observed in human SSc. The antioxidant combination Twendee X® (TwX) is a dietary supplement consisting of vitamins, amino acids, and CoQ10. TwX has been proven to prevent dementia in humans with mild cognitive impairment and significantly improve cognitive impairment in an Alzheimer's disease mouse model by regulating OS through a strong antioxidant capacity that cannot be achieved with a single antioxidant ingredient. We evaluated the effectiveness of TwX on various symptoms of HOCl-induced SSc mice. TwX-treated HOCl-induced SSc mice showed significantly reduced lung and skin fibrosis compared to untreated HOCl-induced SSc mice. TwX also significantly reduced highly oxidized protein products (AOPP) in serum and suppressed Col-1 gene expression and activation of B cells involved in autoimmunity. These findings suggest that TwX has the potential to be a new antioxidant treatment for SSc without side effects.

Chromolaena odorata layered-nitrile rubber polymer transdermal patch enhanced wound healing in vivo.

The objective is to investigate the healing efficacy of a Chromolaena odorata layered-nitrile rubber transdermal patch on excision wound healing in rats. Wounds were induced in Sprague-Dawley rats and were later treated as follows: wound A, the negative control, received no treatment (NC); wound B, the negative control with an empty nitrile rubber patch (NC-ERP); wound C, treated with a C. odorata layered-nitrile rubber patch (CO-NRP); and wound D, the positive control with Solcoseryl gel with a nitrile rubber patch (PC-SG-NRP). After 1, 3, 6, 10, and 14 days, the rats were sacrificed and analyzed for wound contraction, protein content, hexosamine, and uronic acid levels. Macroscopic observation showed enhanced wound healing in wounds treated with CO-NRP with a wound contraction percentage significantly higher (p<0.05) on days 6 and 10 compared to those treated with NC-ERP. Similarly, protein, hexosamine, and uronic acid contents were also significantly higher (p<0.05) in CO-NRP-treated wounds when compared with wounds treated with NC-ERP. Histological findings showed denser collagen deposition and faster granulation tissue formation in wounds treated with CO-NRP. From the results obtained, it is concluded that the C. odorata layered-nitrile rubber transdermal patch was effective in healing skin wounds.

Preparation of Compound Salvia miltiorrhiza-Blumea balsamifera Nanoemulsion Gel and Its Effect on Hypertrophic Scars in the Rabbit Ear Model.

Hypertrophic scars (HS) still remain an urgent challenge in the medical community. Traditional Chinese medicine (TCM) has unique advantages in the treatment of HS. However, due to the natural barrier of the skin, it is difficult for the natural active components of TCM to more effectively penetrate the skin and exert therapeutic effects. Therefore, the development of an efficient drug delivery system to facilitate enhanced transdermal absorption of TCM becomes imperative for its clinical application. In this study, we designed a compound Salvia miltiorrhiza-Blumea balsamifera nanoemulsion gel (CSB-NEG) and investigated its therapeutic effects on rabbit HS models. The prescription of CSB-NEG was optimized by single-factor, pseudoternary phase diagram, and central composite design experiments. The results showed that the average particle size and PDI of the optimized CSB-NE were 46.0 ± 0.2 nm and 0.222 ± 0.004, respectively, and the encapsulation efficiency of total phenolic acid was 93.37 ± 2.56%. CSB-NEG demonstrated excellent stability and skin permeation in vitro and displayed a significantly enhanced ability to inhibit scar formation compared to the CSB physical mixture in vivo. After 3 weeks of CSB-NEG treatment, the scar appeared to be flat, pink, and flexible. Furthermore, this treatment also resulted in a decrease in the levels of the collagen I/III ratio and TGF-ß1 and Smad2 proteins while simultaneously promoting the growth and remodeling of microvessels. These findings suggest that CSB-NEG has the potential to effectively address the barrier properties of the skin and provide therapeutic benefits for HS, offering a new perspective for the prevention and treatment of HS.

Anti-psoriasis effect of 18ß-glycyrrhetinic acid by breaking CCL20/CCR6 axis through its vital active group targeting GUSB/ATF2 signaling.

BACKGROUND: Psoriasis is an immune-mediated chronic inflammatory skin disease. Current research suggests that the long-term persistence and recurrence of psoriasis are closely related to the feedback loop formed between keratinocytes and immune cells, especially in Th 17 or DC cells expressing CCR6. CCL20 is the ligand of CCR6. Therefore, drugs that block the expression of CCL20 or CCR6 may have a certain therapeutic effect on psoriasis. Glycyrrhetinic acid (GA) is the main active ingredient of the plant drug licorice and is often used to treat autoimmune diseases, including psoriasis. However, its mechanism of action is still unclear. METHODS: Psoriasis like skin lesion model was established by continuously applying imiquimod on the back skin of normal mice and CCR6-/- mice for 7 days. The therapeutic and preventive effects of glycyrrhetinic acid (GA) on the model were observed and compared. The severity of skin injury is estimated through clinical PASI scores and histopathological examination. qRT-PCR and multiple cytoline assay were explored to detect the expression levels of cytokines in animal dorsal skin lesions and keratinocyte line HaCaT cells, respectively. The dermis and epidermis of the mouse back were separated for the detection of CCL20 expression. Transcription factor assay was applied to screen, and luciferase activity assay to validate transcription factors regulated by GA. Technology of surface plasmon laser resonance with LC-MS (SPR-MS), molecular docking, and enzyme activity assay were used to identified the target proteins for GA. Finally, we synthesized different derivatives of 18beta-GA and compared their effects, as well as glycyrrhetinic acid (GL), on the skin lesion of imiquimod-induced mice to evaluate the active groups of 18beta-GA. RESULTS: 18ß-glycyrrhetinic acid (GA) improved IMQ-induced psoriatic lesions, and could specifically reduce the chemokine CCL20 level of the epidermis in lesion area, especially in therapeutic administration manner. The process was mainly regulated by transcription factor ATF2 in the keratinocytes. In addition, GUSB was identified as the primary target of 18ßGA. Our findings indicated that the subject on molecular target research of glycyrrhizin should be glycyrrhetinic acid (GA) instead of glycyrrhizic acid (GL), because GL showed little activity in vitro or in vivo. Apart from that, α, ß, -unsaturated carbonyl in C11/12 positions was crucial or unchangeable to its activity of 18ßGA, while proper modification of C3 or C30 position of 18ßGA may vastly increase its activity. CONCLUSION: Our research indicates that 18ßGA exerted its anti-psoriasis effect mainly by suppressing ATF2 and downstream molecule CCL20 predominately through α, ß, -unsaturated carbonyl at C11/12 position binding to GUSB in the keratinocytes, and then broke the feedback loop between keratinocytes and CCR6-expressing immune cells. GA has more advantages than GL in the external treatment of psoriasis. A highlight of this study is to investigate the influence of special active groups on the pharmacological action of a natural product, inspired by the molecular docking result.

Polyphenolic Platform Ameliorated Sanshool for Skin Photoprotection.

Natural evolution has nurtured a series of active molecules that play vital roles in physiological systems, but their further applications have been severely limited by rapid deactivation, short cycle time, and potential toxicity after isolation. For instance, the instability of structures and properties has greatly descended when sanshool is derived from Zanthoxylum xanthoxylum. Herein, natural polyphenols are employed to boost the key properties of sanshool by fabricating a series of nanoparticles (NPs). The intracellular evaluation and in vivo animal model are conducted to demonstrate the decreased photodamage score and skin-fold thickness of prepared NPs, which can be attributed to the better biocompatibility, improved free radical scavenging, down-regulated apoptosis ratios, and reduced DNA double-strand breaks compared to naked sanshool. This work proposes a novel strategy to boost the key properties of naturally occurring active molecules with the assistance of natural polyphenol-based platforms.

Dendrobium officinale flowers' topical extracts improve skin oxidative stress and aging.

BACKGROUND: Dendrobium officinale flowers (DOF) have the effects of antiaging and nourishing yin, but it lacks pharmacological research on skin aging. OBJECTIVE: Confirming the role of DOF in delaying skin aging based on the "in vitro animal-human" model. METHODS: In this experiment, three kinds of free radical scavenging experiments in vitro, D-galactose-induced aging mouse model, and human antiaging efficacy test were used to test whether DOF can improve skin aging through anti-oxidation. RESULTS: In vitro experiment shows that DOF has certain scavenging effect on 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical, hydroxyl free radical, and superoxide free radical, and its IC50 is 0.2090 µg/mL, 15.020, and 1.217 mg/mL respectively. DOF can enhance the activities of T-AOC, SOD, CAT, and GSH Px in the serum of aging mice, increase the content of GSH, and reduce the content of MDA when administered with DOF of 1.0, 2.0, and 4.0 g/kg for 6 weeks. In addition, it can enhance the activity of SOD in the skin of aging mice, increase the content of Hyp, and decrease the content of MDA, activated Keap1/Nrf2 pathway in the skin of aging mice. Applying DOF with a concentration of 0.2 g/mL on the face for 8 weeks can significantly improve the skin water score and elasticity value, reduce facial wrinkles, pores, acne, and UV spots, and improve the facial brown spots and roughness. CONCLUSION: DOF can significantly improve skin aging caused by oxidative stress, and its mechanism may be related to scavenging free radicals in the body and improving skin quality.

Evidence of the protective effect of anti-pollution products against oxidative stress in skin ex vivo using EPR spectroscopy and autofluorescence measurements.

The concentration of air pollution is gradually increasing every year so that daily skin exposure is unavoidable. Dietary supplements and topical formulations currently represent the protective strategies to guard against the effects of air pollution on the body and the skin. Unfortunately, there are not yet enough methods available to measure the effectiveness of anti-pollution products on skin. Here, we present two ex vivo methods for measuring the protective effect against air pollution of different cream formulations on the skin: Electron paramagnetic resonance (EPR) spectroscopy and autofluorescence excited by 785 nm using a confocal Raman microspectrometer (CRM). Smoke from one cigarette was used as a model pollutant. EPR spectroscopy enables the direct measurement of free radicals in excised porcine skin after smoke exposure. The autofluorescence in the skin was measured ex vivo, which is an indicator of oxidative stress. Two antioxidants and a chelating agent in a base formulation and a commercial product containing an antioxidant mixture were investigated. The ex vivo studies show that the antioxidant epigallocatechin-3-gallate (EGCG) in the base cream formulation provided the best protection against oxidative stress from smoke exposure for both methods.

Oral Administration of Apple Pectin Solution Improves Atopic Dermatitis in a Mouse Model.

The development of atopic dermatitis (AD) involves multiple factors. Three such factors are particularly important in AD onset: immune abnormalities, skin barrier dysfunction, and itching. Many studies report that an imbalance between helper T (Th)1 and Th2 cells causes AD. Apple pectin, a prebiotic, has preventative effects in other allergic diseases (e.g., bronchial asthma and AD), but its potential benefits in AD are unclear. In this study, we investigated the effect of oral apple pectin administration on skin inflammation in an AD mouse model and examined changes in T cells involved in AD. To induce AD, a picryl chloride solution was applied to the shaved back skin of male NC/Nga mice. AD mice then received an oral apple pectin solution (0.4% or 4%) for 35 d. Compared with untreated AD mice, mice in both apple pectin-treated groups showed improvement in AD-induced inflammation and skin symptoms. Histological evaluation showed that apple pectin treatment attenuated epidermal thickening and decreased the number of mast cells and CD4+ cells in AD-induced mice. Apple pectin treatment also reduced serum IgE concentration, as well as expression of the inflammation indicator cyclooxygenase-2 and the Th2-related factors thymic stromal lymphopoietin, interleukin-4, and GATA3. Additionally, increased mRNA expression of the genes that encode interferon-γ and T-bet, which are Th1-related factors, and forkhead box protein P3, were observed in the apple pectin-treated groups. Our findings suggest that apple pectin treatment ameliorates AD by increasing regulatory T cells and improving the Th1/Th2 balance in the skin of AD model mice.

Lipidomics-based analysis of lipid differences between dry skin of women aged 22-28 years and 29-35 years.

BACKGROUND: The skin condition of women is different at different ages, and skin surface lipids are also different. According to the "7-7 theory" of the Huangdi Neijing, the physiological condition of women changes significantly every 7 years, and women aged 22-28 are in the "4-7" stage as mentioned in the "7-7 theory" of the Huangdi Neijing. Women's skin is in different states at different ages and produces different lipids. OBJECTIVES: To explore the key lipids that contribute to skin differences between women aged 22-28 and 29-35 years, and to explore the relationship with physiological parameters and daily routine. METHODS: Differential lipids were detected and screened between 22-28 year old (group D1) and 29-35 year old (group D2) dry-skinned women using UPLC-Q-TOF-MS and correlated between the two groups with questionnaires and physiological parameters based on basic information, lifestyle habits, work situation, and emotional stress. RESULTS: The results showed that all of the eight major classes of lipids had the highest expression in the D2 group, with the largest differences in glycerophospholipids, glycerol esters, and fatty acids. The BMI value of D2 group was higher than that of D1 group, the skin elasticity index (R2) and brightness index (L, a, ITA values) were lower than that of D1 group, and Cer (d18:0/16:0) was positively correlated with the R2, L, a, and ITA, and LMSP01080056 (N,N-dimethyl-Safingol) was positively correlated with the b-value, the LMSPGP03020013, LMSPGP03020014, LMSP03020024 were significantly negatively correlated with R2. CONCLUSIONS: Cer(d18:0/16:0) is a neurosphingol that inhibits elastase expression. N,N-dimethyl-Safingol readily undergoes oxidation to form yellow-brown solids. The macromolecular structure and excessive carbonyl structure of [LMGP0302] are susceptible to cross-linking and carbonyl stress reactions, which accelerate skin aging and reduce skin elasticity, and thus, they may be key lipids contributing to skin differences between the two age groups.

An upcycled fraction of Melaleuca alternifolia essential oil regenerates the skin through the skin melatonin pathway and improves sleep quality.

BACKGROUND: Sleep is one of the most important factors affecting overall health. During the night, the skin repairs damage caused by daily stresses. Melatonin plays a key role in this process. Toxins are removed, and cellular repair and growth hormone production are increased. Inter alia, this also decreases signs of intrinsic aging. AIMS: The current study was intended to demonstrate the impact of a unique fraction of Melaleuca alternifolia (FMA) essential oil, on sleep and skin quality. METHODS: The effect of FMA was investigated in vitro on skin cells, evaluating its antioxidant and anti-inflammatory properties, and in an ex-vivo study on human skin biopsies treated with FMA following stress induction. In addition, two clinical studies were performed on volunteers with life-style-related sleep complaints. In one study, sleep was measured using a noncontact monitoring device (SleepScore Labs, Max). A second study was conducted to assess skin anti-aging effects. RESULTS: In vitro application of FMA reduced IL-8 and reactive oxygen species (ROS) generation in skin cells. This was confirmed ex vivo through a decrease in inflammatory markers and an increase in antioxidant enzymes after stress induction. Interestingly, FMA also upregulated melatonin-associated genes. Real-world sleep tracking revealed that FMA significantly improved sleep quality, relative to unscented control. In vivo applications also showed a reduction in signs of aging. CONCLUSION: These results provide initial data to suggest that this unique FMA delivers skin anti-aging benefits via a two-pronged mode of action, improving sleep quality, and reducing skin inflammatory and oxidative stress.

A new lymphedema treatment using pyro-drive jet injection.

Lymphedema, resulting from impaired lymphatic drainage, causes inflammation, fibrosis and tissue damage leading to symptoms such as limb swelling and restricted mobility. Despite various treatments under exploration, no standard effective therapy exists. Here a novel technique using the pyro-drive jet injection (PJI) was used to create artificial clefts between collagen fibers, which facilitated the removal of excess interstitial fluid. The PJI was used to deliver a mixture of lactated Ringer's solution and air into the tail of animals with secondary skin edema. Edema levels were assessed using micro-CT scanning. Histopathological changes and neovascularization were evaluated on the injury-induced regenerative tissue. Regarding tissue remodeling, we focused on connective tissue growth factor (CTGF) and vascular endothelial growth factor (VEGF)-C. PJI markedly diminished soft tissue volume in the experimental lymphedema animals compared to the non-injected counterparts. The PJI groups exhibited a significantly reduced proportion of inflammatory granulation tissue and an enhanced density of lymphatic vessels and α-smooth muscle actin (αSMA)-positive small vessels in the fibrous granulation tissue compared to the controls. In addition, PJI curtailed the prevalence of CTGF- and VEGF-C-positive cells in regenerative tissue. In a lymphedema animal model, PJI notably ameliorated interstitial edema, promoted lymphatic vessel growth, and bolstered αSMA-positive capillaries in fibrous granulation tissue. PJI's minimal tissue impact post-lymph node dissection indicates significant potential as an early, standard preventative measure. Easily applied in general clinics without requiring specialized training, it offers a cost-effective and highly versatile solution to the management of lymphedema.

Evodiae Fructus extract suppresses inflammatory response in HaCaT cells and improves house dust mite-induced atopic dermatitis in NC/Nga mice.

This study was conducted to assess the effect of Evodiae Fructus 70% ethanol extract (EFE) on the pathology of atopic dermatitis using in vitro and in vivo models. The major compounds in EFE were identified by ultra-performance liquid chromatography with tandem mass spectrometry as rutaecarpine, evodiamine, evodol, dehydroevodiamine, limonin, synephrine, evocarpine, dihydroevocarpine, and hydroxyevodiamine. EFE significantly decreased chemokine levels in tumor necrosis factor-α/interferon-γ-stimulated HaCaT cells. In house dust mite-treated NC/Nga mice, topical application of EFE significantly decreased the dermatitis score, epidermal hyperplasia and thickening, mast cell infiltration, and plasma levels of histamine and corticosterone. Thymic stromal lymphopoietin, CD4+ T cells, interleukin-4, and intercellular adhesion molecule-1 expression in the lesioned skin was reduced in the treated mice. The mechanism of EFE was elucidated using transcriptome analysis, followed by experimental validation using Western blotting in HaCaT cells. EFE down-regulated the activation of Janus kinase (JAK)-signal transducers and activators of transcription (STAT) and mitogen-activated protein kinases (MAPK) signaling pathways in HaCaT cells. EFE improves atopic dermatitis-like symptoms by suppressing inflammatory mediators, cytokines, and chemokines by regulating the JAK-STAT and MAPK signaling pathways, suggesting its use as a potential agent for the treatment of atopic dermatitis.

[Application of Hydrogenated Soya Lecithin in Solid Dispersion and Oily Gel, and the Study of Skin-Applied Formulations].

I have been studying the improvement of drug solubility using solid dispersion and skin-applied formulations. When preparing solid dispersions using phosphatidylcoline (PC) as a carrier, drug with hydrogen-donating groups interacts with PC to produce amorphous solid dispersions with high drug content; this overcomes improves drug absorption. The drug was solubilized and supersaturated in the oil-based gel formed with hyadrogenated lecithin; this facilitates drug permeation through the skin. The promoting effect differs with the nature of the oil used because of the skin penetration of the oil itself and the accompanying increase in drug solubility and diffusion coefficient in the skin. At actual application volumes of 10 µL/cm2 or less, the skin penetration of poorly-absorbable drugs depends on the molecular weight and surface tension of the oil. The penetration of the oil vehicle into the upper stratum corneum influences the reach of the drug into the stratum corneum; a high drug concentration near the 7th layer of the stratum corneum promotes migration through the skin by increasing the linear concentration gradient in deeper layers. In addition, we performed a risk assessment, in collaboration with toxicologists, for dermal safety that included the toxicity potential of substances and the parts related to skin transfer.

Photoprotective effects of Lithospermum erythrorhizon and Pueraria lobata extracts on UVB-induced photoaging: A study on skin barrier protection.

AIM: Lithospermum erythrorhizon and Pueraria lobata exhibit promising potential as cosmetic additives for mitigating skin barrier impairment induced by photoaging. Despite their potential, the precise mechanisms underlying their protective and ameliorative effects remain elusive. This study sought to assess the reparative properties of Lithospermum erythrorhizon and Pueraria lobata extracts (LP) on UVB-irradiated human skin keratinocytes (HaCaT cells) and explore the therapeutic potential of LP as a skin barrier protection agent. MATERIALS AND METHODS: Antioxidant activities were gauged through 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), and reactive oxygen species (ROS) assays. The expression levels of skin barrier-related markers, encompassing metalloproteinases (MMPs) and hyaluronidase (HYAL) were scrutinized using enzyme-linked immunosorbent assay (ELISA), reverse transcriptase (RT)-PCR, and Western blotting, with a particular focus on the involvement of the transforming growth factor (TGF)-ß/Smad and nuclear factor-κB (NF-κB) signaling pathways. RESULTS: The study revealed that LP effectively scavenges free radicals, diminishes ROS production in a dose-dependent manner, and significantly attenuates UVB-induced expression of MMP-1 and MMP-3 through modulation of the hyaluronan synthase (HAS)2/HYAL1 signaling axis in UVB-irradiated HaCaT cells. Additionally, LP demonstrated enhanced TGF-ß signaling activation, fostering procollagen type I synthesis, and concurrently exhibited mitogen-activated protein kinases (MAPK)/NF-κB signaling inactivation, thereby mitigating pro-inflammatory cytokine release and alleviating UVB-induced cellular damage. CONCLUSION: In conclusion, the observed protective effects of LP on skin cellular constituents highlight its substantial biological potential for shielding against UVB-induced skin photoaging, positioning it as a promising candidate for both pharmaceutical and cosmetic applications.

Local Multiple-site Injections of a Plasmid Encoding Human MnSOD Mitigate Radiation-induced Skin Injury by Inhibiting Ferroptosis.

BACKGROUND: Most patients who undergo radiotherapy develop radiation skin injury, for which effective treatment is urgently needed. MnSOD defends against reactive oxygen species (ROS) damage and may be valuable for treating radiation-induced injury. Here, we (i) investigated the therapeutic and preventive effects of local multiple-site injections of a plasmid, encoding human MnSOD, on radiation-induced skin injury in rats and (ii) explored the mechanism underlying the protective effects of pMnSOD. METHODS: The recombinant plasmid (pMnSOD) was constructed with human cytomegalovirus (CMV) promoter and pUC-ori. The protective effects of pMnSOD against 20-Gy X-ray irradiation were evaluated in human keratinocytes (HaCaT cells) by determining cell viability, ROS levels, and ferroptosisrelated gene expression. In therapeutic treatment, rats received local multiple-site injections of pMnSOD on days 12, 19, and 21 after 40-Gy γ-ray irradiation. In preventive treatment, rats received pMnSOD injections on day -3 pre-irradiation and on day 4 post-irradiation. The skin injuries were evaluated based on the injury score and pathological examination, and ferroptosis-related gene expression was determined. RESULTS: In irradiated HaCaT cells, pMnSOD transfection resulted in an increased SOD2 expression, reduced intracellular ROS levels, and increased cell viability. Moreover, GPX4 and SLC7A11 expression was significantly upregulated, and erastin-induced ferroptosis was inhibited in HaCaT cells. In the therapeutic and prevention treatment experiments, pMnSOD administration produced local SOD protein expression and evidently promoted the healing of radiation-induced skin injury. In the therapeutic treatment experiments, the injury score in the high-dose pMnSOD group was significantly lower than in the PBS group on day 33 post-irradiation (1.50 vs. 2.80, P < 0.05). In the prevention treatment experiments, the skin injury scores were much lower in the pMnSOD administration groups than in the PBS group from day 21 to day 34. GPX4, SLC7A11, and Bcl-2 were upregulated in irradiated skin tissues after pMnSOD treatment, while ACSL4 was downregulated. CONCLUSION: The present study provides evidence that the protective effects of MnSOD in irradiated HaCaT cells may be related to the inhibition of ferroptosis. The multi-site injections of pMnSOD had clear therapeutic and preventive effects on radiation-induced skin injury in rats. pMnSOD may have therapeutic value for the treatment of radiation-induced skin injury.

Rheological Properties and Composition Affecting the Skin Permeation of a Model of a Hydrophilic Drug in Lecithin Reverse Wormlike Micelles.

We investigated the effect of the rheological properties and composition of lecithin reverse wormlike micelles (LRWs) on the skin permeation of a model of a hydrophilic drug to determine whether LRWs support uniform hydrophilic drug/oil-based formulations and good drug penetrate into skin. Here, we prepared LRWs with D (-)-ribose (RI) or glycerol (GL) as polar compounds, liquid paraffin (LP) or isopropyl myristate (IPM) as oils, and 6-carboxyfluorescein (CF) as a model for a hydrophilic drug, and evaluated the rheological properties and skin penetration characteristics of the preparations. The LRWs showed moderate viscosity at 25 °C, a typical storage temperature, but decreasing viscosity at 32 °C, the surface temperature of human skin, suggesting that the LRWs would penetrate the microstructure of skin (e.g., wrinkles and hair follicles). The highest skin permeability of CF was observed when IPM was used as the oil, suggesting that both the stratum corneum and hair follicle routes are involved in drug permeation. The penetration of CF into hair follicles is influenced not only by the rheology of the formulation but also by the interaction between IPM and sebum in the hair follicles.

Effect of Receptor Solution in Studies of In Vitro Permeation Test (IVPT).

In Vitro Permeation Test (IVPT) is commonly used to evaluate skin penetration of chemicals and performance of dermatological products. For a permeant with low aqueous solubility, an additive that is expected not to alter the skin barrier can be used in the receptor solution to improve permeant solubility. The objective of this study was to (a) evaluate the effects of these additives in IVPT receptor solution on skin permeability of model permeants and skin electrical resistance and (b) determine the solubility of the permeants in these receptor solutions. Bovine serum albumin (BSA), 2-hydroxypropyl-beta-cyclodextrin (HPCD), ethanol, nonionic surfactant Brij-98, and propylene glycol were the additives, and phosphate buffered saline (PBS) was the control. Steady-state skin permeability coefficients and resistances were determined. The receptor solutions examined in this study did not cause a significant increase in skin permeability or decrease in resistance (less than 40 % changes) except 25 % ethanol. The receptor solution containing 25 % ethanol induced an approximately twofold average increase in skin permeability and reduced skin electrical resistance by approximately threefold. The receptor solution of 2.5 % HPCD provided the highest levels of solubility for the model lipophilic permeants, while 0.2 % Brij-98 and 5 % ethanol showed the lowest solubility enhancement from those in PBS.