Role of Matrix Metalloproteinases in Photoaging and Photocarcinogenesis

The molecular subtypes of autoimmune diseases

Autoimmune diseases (ADs) are characterized by their complexity and a wide range of clinical differences. Despite patients presenting with similar symptoms and disease patterns, their reactions to treatments may vary. The current approach of personalized medicine, which relies on molecular data, is seen as an effective method to address the variability in these diseases. This review examined the pathologic classification of ADs, such as multiple sclerosis and lupus nephritis, over time. Acknowledging the limitations inherent in pathologic classification, the focus shifted to molecular classification to achieve a deeper insight into disease heterogeneity. The study outlined the established methods and findings from the molecular classification of ADs, categorizing systemic lupus erythematosus (SLE) into four subtypes, inflammatory bowel disease (IBD) into two, rheumatoid arthritis (RA) into three, and multiple sclerosis (MS) into a single subtype. It was observed that the high inflammation subtype of IBD, the RA inflammation subtype, and the MS "inflammation & EGF" subtype share similarities. These subtypes all display a consistent pattern of inflammation that is primarily driven by the activation of the JAK-STAT pathway, with the effective drugs being those that target this signaling pathway. Additionally, by identifying markers that are uniquely associated with the various subtypes within the same disease, the study was able to describe the differences between subtypes in detail. The findings are expected to contribute to the development of personalized treatment plans for patients and establish a strong basis for tailored approaches to treating autoimmune diseases.

Unveiling the metabolites underlying the skin anti-ageing properties of Cytinus hypocistis (L.) L. through a biochemometric approach

BACKGROUND

The genus Cytinus, recognised as one of the most enigmatic in the plant kingdom, has garnered attention for its bioactive potential, particularly its skin anti-ageing properties. Despite this recognition, much remains to be accomplished regarding deciphering and isolating its most active compounds.

HYPOTHESIS

This study aimed to identify the compounds responsible for C. hypocistis skin anti-ageing potential.

METHODS

Using multivariate analysis, a biochemometric approach was applied to identify the discriminant metabolites by integrating extracts' chemical profile (Liquid Chromatography-High-Resolution Mass Spectrometry, LCHRMS) and bioactive properties. The identified bioactive metabolite was structurally elucidated by 1D and 2D Nuclear Magnetic Resonance (NMR).

RESULTS

Among the studied bioactivities, the anti-elastase results exhibited a significant variation among the samples from different years. After the biochemometric analysis, the compound 2,3:4,6-bis(hexahydroxydiphenoyl)glucose, with a molecular mass of 784.075 Da, was structurally elucidated as the discriminant feature responsible for the outstanding human neutrophil elastase inhibition. Remarkably, the subfraction containing this compound exhibited a tenfold improvement in neutrophil elastase inhibition efficacy compared to the crude extract; its effectiveness fell within the same range as SPCK, a potent irreversible neutrophil elastase inhibitor. Moreover, this subfraction displayed no cytotoxicity or phototoxicity and excellent efficacy for the tested anti-ageing properties.

CONCLUSIONS

Hydrolysable tannins were confirmed as the metabolites behind C. hypocistis skin anti-ageing properties, effectively mitigating critical molecular mechanisms that influence the phenotypically distinct ageing clinical manifestations. Pedunculagin was particularly effective in inhibiting neutrophil elastase, considered one of the most destructive enzymes in skin ageing.

A study on the anti-senescent effects of flavones derived from Prinsepia utilis Royle seed residue

ETHNOPHARMACOLOGICAL RELEVANCE

Prinsepia utilis Royle, also known as the Anas fruit, is a unique perennial woody oil plant from Yunnan Province, China. In the ancient texts of Dongba sutras and Yunnan Southern Materia Medica, it has been documented that the local Naxi, Tibetan, and Mosuo communities extensively utilize the root and leaf fruits of green thorns for various purposes. These include treating mild-to-moderate specific dermatitis, moisturising the skin, providing protection against UV damage, aiding childbirth in pregnant women, safeguarding stomach health, reducing the risk of arteriosclerosis, and delaying aging.

AIM OF THE STUDY

In this study, leftover residues from oil extraction were efficiently reused, and flavonoids were identified during subsequent extraction and separation processes. The anti-senescent effects of flavonoids in P. utilis Royle have not been systematically studied. Therefore, the objective of this study was to explore the anti-senescent properties of the flavonoids obtained from P. utilis Royle.

METHODS

First, HPLC and other analytical techniques were used to identify the components of the P. utilis Royle flavonoid (PURF). Next, DPPH, hydroxyl radicals, superoxide anion O2-, collagenase, and elastase were initially detected using in vitro biochemical assays. To examine its antioxidant properties, a zebrafish model was used, and to confirm its anti-senescent effects, a d-galactose-induced mouse aging model was employed. The anti-senescent mechanism of PURF was examined using a natural senescence HFF model. Furthermore, the anti-senescent target was confirmed using a 3D full T-Skin™ model.

RESULTS

In vitro biochemical assays demonstrated that flavones exhibited potent antioxidant activity and anti-senescent potential by inhibiting DPPH, hydroxyl radicals, superoxide anion O2-, collagenase, and elastase. It significantly enhanced the antioxidant effect on zebrafish while suppressing ROS and inflammatory injury, up-regulating COL1A1, COL3A1, AMPK, and mTOR gene expression and down-regulating MMP-9, TGF-β, p21, and p16 gene expression suggesting its potential anti-senescent ability. Findings from the D-galactose-induced aging mouse model showed that PURF greatly increased SOD levels, while simultaneously decreasing HYP and MDA levels. In addition, when PURF was given to the HFF cell and 3D full T-Skin™ model, consistent trends were observed in gene and protein expression, with up-regulation of COL1A1, COL3A1, AMPK, and mTOR genes and down-regulation of TGF-β, MMP-1, MMP-9, p21, and p16 genes. Therefore, these preliminary findings indicate that flavones can modulate AMPK/mTOR/TGF-β signalling pathways to exert its influence.

CONCLUSION

The kernel residue of natural P. utilis Royle oil extracted from Yunnan province was previously considered agricultural waste, but we successfully extracted and isolated its flavonoid components. Our preliminary studies demonstrated its potential as an environmentally friendly anti-senescent raw material.

Exosomal lncRNA SNHG12 promotes angiogenesis and breast cancer progression

OBJECTIVE

Breast cancer is one of the most prevalent malignancies in women. Exosomes are important mediators of intercellular communication; however, their regulatory mechanisms in human umbilical vein endothelial cells (HUVECs) angiogenesis in breast cancer remain unknown.

METHODS

We isolated and characterized breast cancer cell-derived exosomes and investigated their functions. Exosomal sequencing and the TCGA database were used to screen long non-coding RNA (lncRNA). In vitro and in vivo experiments were performed to investigate the role of exosomal lncRNA in HUVEC angiogenesis and tumor growth. Molecular methods were used to demonstrate the molecular mechanism of lncRNA.

RESULTS

We demonstrated that breast cancer cell-derived exosomes promoted HUVEC proliferation, tube formation, and migration. Combining exosomal sequencing results with The Cancer Genome Atlas Breast Cancer database, we screened lncRNA small nucleolar RNA host gene 12 (SNHG12), which was highly expressed in breast cancer cells. SNHG12 was also upregulated in HUVECs co-cultured with exosome-overexpressed SNHG12. Moreover, overexpression of SNHG12 in exosomes increased HUVEC proliferation and migration, whereas deletion of SNHG12 in exosomes showed the opposite effects. In vivo experiments showed that SNHG12 knockdown in exosomes inhibited breast cancer tumor growth. Transcriptome sequencing identified MMP10 as the target gene of SNHG12. Functional experiments revealed that MMP10 overexpression promoted HUVEC angiogenesis. Mechanistically, SNHG12 blocked the interaction between PBRM1 and MMP10 by directly binding to PBRM1. Moreover, exosomal SNHG12 promoted HUVEC angiogenesis via PBRM1 and MMP10.

CONCLUSIONS

In summary, our findings confirmed that exosomal SNHG12 promoted HUVEC angiogenesis via the PBRM1-MMP10 axis, leading to enhanced malignancy of breast cancer. Exosomal SNHG12 may be a novel therapeutic target for breast cancer.

Protective effect of mixture of Acanthopanax sessiliflorum and Chaenomeles sinensis against ultraviolet B-induced photodamage in human fibroblast and hairless mouse

Skin photoaging, characterized by collagen degradation and upregulation of matrix metalloproteinases (MMPs), is a major concern caused by UVB irradiation. In this study, we investigated the potential of Acanthopanax sessiliflorum extract (ASE) and Chaenomeles sinensis (CSE) extracts to mitigate the effects of UVB-induced photodamage in human fibroblast and hairless mice. Water extracts of AS (ASE) and CS (CSE) were found to inhibit the expression of MMP-1/-3 in vitro. Furthermore, the extract of mixture of AS and CS (ACE) showed more potent inhibitor effect, as compared to ASE and CSE. In UVB-irradiated hairless mice, oral administration of ACE effectively reduced wrinkle formation, skin roughness, and epidermal thickness while promoting the deposition of collagenous fibers. These results indicate that ACE has the potential to protect against skin photoaging by restoring the impaired skin via downregulation of MMP-1/-3 expression and secretion. Our findings highlight the therapeutic potential of ACE in mitigating skin photoaging.

Supplementary Information

The online version contains supplementary material available at 10.1007/s10068-023-01462-3.

Deciphering styrene oxide tolerance mechanisms in Gluconobacter oxydans mutant strain

Chemical production wastewater contains large amounts of organic solvents (OSs), which pose a significant threat to the environment. In this study, a 10 g·L-1 styrene oxide tolerant strain with broad-spectrum OSs tolerance was obtained via adaptive laboratory evolution. The mechanisms underlying the high OS tolerance of tolerant strain were investigated by integrating physiological, multi-omics, and genetic engineering analyses. Physiological changes are one of the main factors responsible for the high OS tolerance in mutant strains. Moreover, the P-type ATPase GOX_RS04415 and the LysR family transcriptional regulator GOX_RS04700 were also verified as critical genes for styrene oxide tolerance. The tolerance mechanisms of OSs can be used in biocatalytic chassis cell factories to synthesize compounds and degrade environmental pollutants. This study provides new insights into the mechanisms underlying the toxicological response to OS stress and offers potential targets for enhancing the solvent tolerance of G. oxydans.

INHBA regulates Hippo signaling to confer 5-FU chemoresistance mediated by cellular senescence in colon cancer cells

Colon cancer has become a global public health challenge, and 5-Fluorouracil (5-FU) chemoresistance is a major obstacle in its treatment. Chemoresistance can be mediated by therapy-induced cellular senescence. This study intended to investigate mechanisms of INHBA (inhibin A) in 5-FU resistance mediated by cellular senescence in colon cancer. Bioinformatics analysis of INHBA expression in colon cancer tissues, survival analysis, and correlation analysis of cellular senescence markers were performed. The effects of INHBA on the biological characteristics and 5-FU resistance of colon cancer cells were examined through loss/gain-of-function and molecular assays. Finally, a xenograft mouse model was built to validate the mechanism of INHBA in vivo. INHBA was upregulated in colon cancer and was significantly positively correlated with cellular senescence markers uncoupling protein 2 (UCP-2), matrix metalloproteinase-1 (MMP-1), dense and erect panicle 1 (DEP1), and p21. Cellular senescence in colon cancer mediated 5-FU resistance. Downregulation of INHBA expression enhanced 5-FU sensitivity in colon cancer cells, inhibited cell proliferation, promoted apoptosis, increased the proportion of cells in G0/G1 phase, and it resulted in a lower proportion of senescent cells and lower levels of the cellular senescence markers interleukin 6 (IL-6) and interleukin 8 (IL-8). Analysis of whether to use the pathway inhibitor Verteporfin proved that INHBA facilitated colon cancer cell senescence and enhanced 5-FU chemoresistance via inactivation of Hippo signaling pathway, and consistent results were obtained in vivo. Collectively, INHBA conferred 5-FU chemoresistance mediated by cellular senescence in colon cancer cells through negative regulation of Hippo signaling.

Black soldier fly (Hermetia illucens L.): A potential small mighty giant in the field of cosmeceuticals

Background and Aims

Natural products are widely used in the pharmaceutical and cosmetics industries due to their high-value bioactive compounds, which make for "greener" and more environmentally friendly ingredients. These natural compounds are also considered a safer alternative to antibiotics, which may result in antibiotic resistance as well as unfavorable side effects. The development of cosmeceuticals, which combine the cosmetic and pharmaceutical fields to create skincare products with therapeutic value, has increased the demand for unique natural resources. The objective of this review is to discuss the biological properties of extracts derived from larvae of the black soldier fly (BSF; Hermetia illucens), the appropriate extraction methods, and the potential of this insect as a novel active ingredient in the formulation of new cosmeceutical products. This review also addresses the biological actions of compounds originating from the BSF, and the possible association between the diets of BSF larvae and their subsequent bioactive composition.

Methods

A literature search was conducted using PubMed and Google Scholar to identify and evaluate the various biological properties of the BSF.

Results

One such natural resource that may be useful in the cosmeceutical field is the BSF, a versatile insect with numerous potential applications due to its nutrient content and scavenging behavior. Previous research has also shown that the BSF has several biological properties, including antimicrobial, antioxidant, anti-inflammatory, and wound healing effects.

Conclusion

Given the range of biological activities and metabolites possessed by the BSF, this insect may have the cosmeceutical potential to treat a number of skin pathologies.

Role of umbilical cord mesenchymal stromal cells in skin rejuvenation

Aging is the main cause of many degenerative diseases. The skin is the largest and the most intuitive organ that reflects the aging of the body. Under the interaction of endogenous and exogenous factors, there are cumulative changes in the structure, function, and appearance of the skin, which are characterized by decreased synthesis of collagen and elastin, increased wrinkles, relaxation, pigmentation, and other aging characteristics. skin aging is inevitable, but it can be delayed. The successful isolation of mesenchymal stromal cells (MSC) in 1991 has greatly promoted the progress of cell therapy in human diseases. The International Society for Cellular Therapy (ISCT) points out that the MSC is a kind of pluripotent progenitor cells that have self-renewal ability (limited) in vitro and the potential for mesenchymal cell differentiation. This review mainly introduces the role of perinatal umbilical cord-derived MSC(UC-MSC) in the field of skin rejuvenation. An in-depth and systematic understanding of the mechanism of UC-MSCs against skin aging is of great significance for the early realization of the clinical transformation of UC-MSCs. This paper summarized the characteristics of skin aging and summarized the mechanism of UC-MSCs in skin rejuvenation reported in recent years. In order to provide a reference for further research of UC-MSCs to delay skin aging.

Radiofrequency Treatment Attenuates Age-Related Changes in Dermal-Epidermal Junctions of Animal Skin

The dermal-epidermal junction (DEJ) is essential for maintaining skin structural integrity and regulating cell survival and proliferation. Thus, DEJ rejuvenation is key for skin revitalization, particularly in age-related DEJ deterioration. Radiofrequency (RF) treatment, known for its ability to enhance collagen fiber production through thermal mechanisms and increase heat shock protein (HSP) expression, has emerged as a promising method for skin rejuvenation. Additionally, RF activates Piezo1, an ion channel implicated in macrophage polarization toward an M2 phenotype and enhanced TGF-β production. This study investigated the impact of RF treatment on HSP47 and HSP90 expression, known stimulators of DEJ protein expression. Furthermore, using in vitro and aged animal skin models, we assessed whether RF-induced Piezo1 activation and the subsequent M2 polarization could counter age-related DEJ changes. The RF treatment of H2O2-induced senescent keratinocytes upregulated the expression of HSP47, HSP90, TGF-β, and DEJ proteins, including collagen XVII. Similarly, the RF treatment of senescent macrophages increased Piezo1 and CD206 (M2 marker) expression. Conditioned media from RF-treated senescent macrophages enhanced the expression of TGF-β and DEJ proteins, such as nidogen and collagen IV, in senescent fibroblasts. In aged animal skin, RF treatment increased the expression of HSP47, HSP90, Piezo1, markers associated with M2 polarization, IL-10, and TGF-β. Additionally, RF treatment enhanced DEJ protein expression. Moreover, RF reduced lamina densa replication, disrupted lesions, promoted hemidesmosome formation, and increased epidermal thickness. Overall, RF treatment effectively enhanced DEJ protein expression and mitigated age-related DEJ structural changes by increasing HSP levels and activating Piezo1.

Rosarugosides A and D from Rosa rugosa Flower Buds: Their Potential Anti-Skin-Aging Effects in TNF-α-Induced Human Dermal Fibroblasts

This present study investigated the anti-skin-aging properties of Rosa rugosa. Initially, phenolic compounds were isolated from a hot water extract of Rosa rugosa's flower buds. Through repeated chromatography (column chromatography, MPLC, and prep HPLC), we identified nine phenolic compounds (1-9), including a previously undescribed depside, rosarugoside D (1). The chemical structure of 1 was elucidated via NMR, HR-MS, UV, and hydrolysis. Next, in order to identify bioactive compounds that are effective against TNF-α-induced NHDF cells, we measured intracellular ROS production in samples treated with each of the isolated compounds (1-9). All isolates reduced the level of ROS at a concentration of 10 μM. Particularly, two depsides-rosarugosides A and D (2 and 1)-significantly inhibited ROS expression in TNF-α-induced NHDFs compared to the other phenolic compounds. Subsequently, the production of MMP-1 and procollagen type Ι α1 by these two depsides was examined. Remarkably, rosarugoside A (2) significantly decreased MMP-1 secretion at all concentrations. In contrast, rosarugoside D (1) regulated the expression of procollagen type Ι α1. These findings collectively suggest that Rosa rugosa extracts and their isolated compounds, rosarugosides A (2) and D (1), hold significant potential for protecting against aging and skin damage. Overall, these findings suggest that Rosa rugosa extracts and their isolated compounds, rosarugosides A (2) and D (1), have the potential to prevent and protect against aging and skin damage, although more specific quantitative analysis is needed.

Silymarin inhibits dermal gelatinolytic activity and reduces cutaneous inflammation

Milk thistle (Silybum marianum) is well-known for its antioxidant activity due to the presence of silymarin. Albeit some studies show a potential for skin inflammation, its activity against dermal MMP-9 and MMP-2 remains to be studied. Silymarin isolated from an S. marianum herbal extract was tested for gelatinase inhibition in the presence of isolated MMP-9 and in dermal adenocarcinome HaCaT cells. Silymarin was then further tested in vivo, using a cutaneous inflammation mice model mediated by reactive oxygen species. Silymarin was able to significantly inhibit gelatinolytic activity in vitro without impairing cell growth and viability. Furthermore, inhibition was more pronounced in cells than with the isolated gelatinase, suggesting an additional effect upon metabolic pathways. In vivo, silymarin was able to reduce ear edema up to 74% and attenuated histological lesions. Results highlight silymarin potential for application in skin inflammatory disorders via gelatinase inhibition.

Perturbed collagen metabolism underlies lymphatic recanalization failure in Gata2 heterozygous deficient mice

Lymphedema has become a global health issue following the growing number of cancer surgeries. Curative or supportive therapeutics have long been awaited for this refractory condition. Transcription factor GATA2 is crucial in lymphatic development and maintenance, as GATA2 haploinsufficient disease often manifests as lymphedema. We recently demonstrated that Gata2 heterozygous deficient mice displayed delayed lymphatic recanalization upon lymph node resection. However, whether GATA2 contributes to lymphatic regeneration by functioning in the damaged lymph vessels' microenvironment remains explored. In this study, our integrated analysis demonstrated that dermal collagen fibers were more densely accumulated in the Gata2 heterozygous deficient mice. The collagen metabolism-related transcriptome was perturbed, and collagen matrix contractile activity was aberrantly increased in Gata2 heterozygous embryonic fibroblasts. Notably, soluble collagen placement ameliorated delayed lymphatic recanalization, presumably by modulating the stiffness of the extracellular matrix around the resection site of Gata2 heterozygous deficient mice. Our results provide valuable insights into mechanisms underlying GATA2-haploinsufficiency-mediated lymphedema and shed light on potential therapeutic avenues for this intractable disease.

The Ocean's Pharmacy: Health Discoveries in Marine Algae

Non-communicable diseases (NCDs) represent a global health challenge, constituting a major cause of mortality and disease burden in the 21st century. Addressing the prevention and management of NCDs is crucial for improving global public health, emphasizing the need for comprehensive strategies, early interventions, and innovative therapeutic approaches to mitigate their far-reaching consequences. Marine organisms, mainly algae, produce diverse marine natural products with significant therapeutic potential. Harnessing the largely untapped potential of algae could revolutionize drug development and contribute to combating NCDs, marking a crucial step toward natural and targeted therapeutic approaches. This review examines bioactive extracts, compounds, and commercial products derived from macro- and microalgae, exploring their protective properties against oxidative stress, inflammation, cardiovascular, gastrointestinal, metabolic diseases, and cancer across in vitro, cell-based, in vivo, and clinical studies. Most research focuses on macroalgae, demonstrating antioxidant, anti-inflammatory, cardioprotective, gut health modulation, metabolic health promotion, and anti-cancer effects. Microalgae products also exhibit anti-inflammatory, cardioprotective, and anti-cancer properties. Although studies mainly investigated extracts and fractions, isolated compounds from algae have also been explored. Notably, polysaccharides, phlorotannins, carotenoids, and terpenes emerge as prominent compounds, collectively representing 42.4% of the investigated compounds.

Comparison of photodamage in non-pigmented and pigmented human skin equivalents exposed to repeated ultraviolet radiation to investigate the role of melanocytes in skin photoprotection

Introduction

Daily solar ultraviolet (UV) radiation has an important impact on skin health. Understanding the initial events of the UV-induced response is critical to prevent deleterious conditions. However, studies in human volunteers have ethical, technical, and economic implications that make skin equivalents a valuable platform to investigate mechanisms related to UV exposure to the skin. In vitro human skin equivalents can recreate the structure and function of in vivo human skin and represent a valuable tool for academic and industrial applications. Previous studies have utilised non-pigmented full-thickness or pigmented epidermal skin equivalents to investigate skin responses to UV exposure. However, these do not recapitulate the dermal-epidermal crosstalk and the melanocyte role in photoprotection that occurs in vivo. In addition, the UV radiation used in these studies is generally not physiologically representative of real-world UV exposure.

Methods

Well-characterised pigmented and non-pigmented skin equivalents that contain human dermal fibroblasts, endogenous secreted extracellular matrix proteins (ECM) and a well-differentiated and stratified epidermis have been developed. These constructs were exposed to UV radiation for ×5 consecutive days with a physiologically relevant UV dose and subsequently analysed using appropriate end-points to ascertain photodamage to the skin.

Results

We have described that repeated irradiation of full-thickness human skin equivalents in a controlled laboratory environment can recreate UV-associated responses in vitro, mirroring those found in photoexposed native human skin: morphological damage, tanning, alterations in epidermal apoptosis, DNA lesions, proliferation, inflammatory response, and ECM-remodelling.

Discussion

We have found a differential response when using the same UV doses in non-pigmented and pigmented full-thickness skin equivalents, emphasising the role of melanocytes in photoprotection.

Enhancement of skin rejuvenation and hair growth through novel near-infrared light emitting diode (nNIR) lighting: in vitro and in vivo study

The study aimed to explore the impact of a novel near-infrared LED (nNIR) with an extended spectrum on skin enhancement and hair growth. Various LED sources, including White and nNIRs, were compared across multiple parameters: cytotoxicity, adenosine triphosphate (ATP) synthesis, reactive oxygen species (ROS) reduction, skin thickness, collagen synthesis, collagenase expression, and hair follicle growth. Experiments were conducted on human skin cells and animal models. Cytotoxicity, ATP synthesis, and ROS reduction were evaluated in human skin cells exposed to nNIRs and Whites. LED irradiation effects were also studied on a UV-induced photoaging mouse model, analyzing skin thickness, collagen synthesis, and collagenase expression. Hair growth promotion was examined as well. Results revealed both White and nNIR were non-cytotoxic to human skin cells. nNIR enhanced ATP and collagen synthesis while reducing ROS levels, outperforming the commonly used 2chip LEDs. In the UV-induced photoaging mouse model, nNIR irradiation led to reduced skin thickness, increased collagen synthesis, and lowered collagenase expression. Additionally, nNIR irradiation stimulated hair growth, augmented skin thickness, and increased hair follicle count. In conclusion, the study highlighted positive effects of White and nNIR irradiation on skin and hair growth. However, nNIR exhibited superior outcomes compared to White. Its advancements in ATP content, collagen synthesis, collagenase inhibition, and hair growth promotion imply increased ATP synthesis activity. These findings underscore nNIR therapy's potential as an innovative and effective approach for enhancing skin and promoting hair growth.

Resveratrol activates autophagy and protects from UVA-induced photoaging in human skin fibroblasts and the skin of male mice by regulating the AMPK pathway

Skin photoaging is mostly caused by ultraviolet A (UVA), although active medications to effectively counteract UVA-induced photoaging have not yet been created. Resveratrol, a naturally occurring polyphenol found in the skin of grapes, has been shown to have various biological functions such as anti-inflammatory and antioxidant characteristics. However, the role of resveratrol in UVA-induced photoaging has not been clarified. We investigated the mechanism of action of resveratrol by UVA irradiation of human skin fibroblasts (HSF) and innovatively modified a mouse model of photoaging. The results demonstrated that resveratrol promoted AMP-activated protein kinase (AMPK) phosphorylation to activate autophagy, reduce reactive oxygen species (ROS) production, inhibit apoptosis, and restore normal cell cycle to alleviate UVA-induced photoaging. In addition, subcutaneous injection of resveratrol not only improved the symptoms of roughness, erythema, and increased wrinkles in the skin of UVA photodamaged mice, but also alleviated epidermal hyperkeratosis and hyperpigmentation, reduced inflammatory responses, and inhibited collagen fiber degradation. In conclusion, our studies proved that resveratrol can treat UVA-induced photoaging and elucidated the possible molecular mechanisms involved, providing a new therapeutic strategy for future anti-aging.

Combined exposure to UV and PM affect skin oxinflammatory responses and it is prevented by antioxidant mix topical application: Evidences from clinical study

BACKGROUND

Exposure to environmental stressors like particulate matter (PM) and ultraviolet radiation (UV) induces cutaneous oxidative stress and inflammation and leads to skin barrier dysfunction and premature aging. Metals like iron or copper are abundant in PM and are known to contribute to reactive oxygen species (ROS) production.

AIMS

Although it has been suggested that topical antioxidant may be able to help in preventing and/or reducing outdoor skin damage, limited clinical evidence under real-life exposure conditions have been reported. The aim of the present study was to evaluate the ability of a topical serum containing 15% ascorbic acid, 0.5% ferulic acid, and 1% tocopherol (CF Mix) to prevent oxinflammatory skin damage and premature aging induced by PM + UV in a human clinical trial.

METHODS

A 4-day single-blinded, clinical study was conducted on the back of 15 females (18-40 years old). During the 4 consecutive days, the back test zones were treated daily with or without the CF Mix, followed by with/without 2 h of PM and 5 min of UV daily exposure.

RESULTS

Application of the CF Mix prevented PM + UV-induced skin barrier perturbation (Involucrin and Loricrin), lipid peroxidation (4HNE), inflammatory markers (COX2, NLRP1, and AhR), and MMP9 activation. In addition, CF Mix was able to prevent Type I Collagen loss.

CONCLUSION

This is the first human study confirming the multipollutants cutaneous damage and suggesting the utility of a daily antioxidant topical application to prevent pollution induced skin damage.

A Novel Trypsin Kunitz-Type Inhibitor from Cajanus cajan Leaves and Its Inhibitory Activity on New Cancer Serine Proteases and Its Effect on Tumor Cell Growth

A novel trypsin inhibitor from Cajanus cajan (TIC) fresh leaves was partially purified by affinity chromatography. SDS-PAGE revealed one band with about 15 kDa with expressive trypsin inhibitor activity by zymography. TIC showed high affinity for trypsin (Ki = 1.617 μM) and was a competitive inhibitor for this serine protease. TIC activity was maintained after 24 h of treatment at 70 °C, after 1 h treatments with different pH values, and β-mercaptoethanol increasing concentrations, and demonstrated expressive structural stability. However, the activity of TIC was affected in the presence of oxidizing agents. In order to study the effect of TIC on secreted serine proteases, as well as on the cell culture growth curve, SK-MEL-28 metastatic human melanoma cell line and CaCo-2 colon adenocarcinoma was grown in supplemented DMEM, and the extracellular fractions were submitted salting out and affinity chromatography to obtain new secreted serine proteases. TIC inhibited almost completely, 96 to 89%, the activity of these serine proteases and reduced the melanoma and colon adenocarcinoma cells growth of 48 and 77% respectively. Besides, it is the first time that a trypsin inhibitor was isolated and characterized from C. cajan leaves and cancer serine proteases were isolated and partial characterized from SK-MEL-28 and CaCo-2 cancer cell lines. Furthermore, TIC shown to be potent inhibitor of tumor protease affecting cell growth, and can be one potential drug candidate to be employed in chemotherapy of melanoma and colon adenocarcinoma.

Preparation of Multifunctional Seaweed Polysaccharides Derivatives Composite Hydrogel to Protect Ultraviolet B-Induced Photoaging In Vitro and In Vivo

Seaweed polysaccharides can be used for protective skin photoaging which is caused by long-term exposure to ultraviolet B (UVB). In this study, a multifunctional composite hydrogel (FACP5) is prepared using sulfated galactofucan polysaccharides, alginate oligosaccharides as active ingredients, and polyacrylonitrile modified κ-Carrageenan as substrate. The properties of FACP5 show that it has good water retention, spreadability, and adhesion. The antiphotoaging activity is evaluated in vitro and in vivo. In vitro experiments demonstrate that the components of FACP5 exhibit good biocompatibility, antioxidant, and anti-tyrosinase activities, and could reduce the cell death rate induced by UVB. In vivo experiments demonstrate that, compared with the mice skin in model group, the skin water content treated with FACP5 increases by 29.80%; the thicknesses of epidermis and dermis decrease by 53.56% and 43.98%, respectively; the activities of catalase and superoxide dismutase increase by 1.59 and 0.72 times, respectively; the contents of interleukin-6 and tumor necrosis factor-α decrease by 19.21% and 17.85%, respectively; hydroxyproline content increases by 32.42%; the expression level of matrix metalloproteinase-3 downregulates by 42.80%. These results indicate that FACP5 has skin barrier repairing, antioxidant, anti-inflammatory, and inhibiting collagen degradation activies, FACP5 can be used as a skin protection remedy for photoaging.

The effects of advanced glycation end-products on skin and potential anti-glycation strategies

The advanced glycation end-products (AGEs) are produced through non-enzymatic glycation between reducing sugars and free amino groups, such as proteins, lipids or nucleic acids. AGEs can enter the body through daily dietary intake and can also be generated internally via normal metabolism and external stimuli. AGEs bind to cell surface receptors for AGEs, triggering oxidative stress and inflammation responses that lead to skin ageing and various diseases. Evidence shows that AGEs contribute to skin dysfunction and ageing. This review introduces the basic information, the sources, the metabolism and absorption of AGEs. We also summarise the detrimental mechanisms of AGEs to skin ageing and other chronic diseases. For the potential strategies for counteracting AGEs to skin and other organs, we summarised the pathways that could be utilised to resist glycation. Chemical and natural-derived anti-glycation approaches are overviewed. This work offers an understanding of AGEs to skin ageing and other chronic diseases and may provide perspectives for the development of anti-glycation strategies.

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.

Discovery of matrix metalloproteinase inhibitors as anti-skin photoaging agents

Photodamage is the result of prolonged exposure of the skin to sunlight. This exposure causes an overexpression of matrix metalloproteinases (MMPs), leading to the abnormal degradation of collagen in the skin tissue and resulting in skin aging and damage. This review presents a detailed overview of MMPs as a potential target for addressing skin aging. Specifically, we elucidated the precise mechanisms by which MMP inhibitors exert their anti-photoaging effects. Furthermore, we comprehensively analyzed the current research progress on MMP inhibitors that demonstrate significant inhibitory activity against MMPs and anti-skin photoaging effects. The review also provides insights into the structure-activity relationships of these inhibitors. Our objective in conducting this review is to provide valuable practical information to researchers engaged in investigations on anti-skin photoaging.

Anti-oxidative, anti-apoptotic, and anti-inflammatory activities of Connarus semidecandrus Jack ethanol extract in UVB-irradiated human keratinocytes

ETHNOPHARMACOLOGICAL RELEVANCE

Connarus semidecandrus Jack (Family: connaraceae) is a medicinal plant known for its wide distribution throughout Southeast Asia. Renowned for its diverse therapeutic properties, it has been traditionally used for treating fever, skin irritation, and colic.

AIM OF THE STUDY

Numerous individuals suffer from skin issues, including wrinkles, hyperpigmentation, and inflammation, due to environmental factors. Although many drugs are available to treat skin problems, chemical drugs have many shortcomings and side effects. Therefore, natural products are attractive potential medicines for alleviating skin troubles. We recently showed that Connarus semidecandrus Jack ethanol extract (Cs-EE) has anti-alopecia potential. This paper aims to explore the potential skin-protective effects and underlying molecular mechanisms of Connarus semidecandrus Jack in UVB-induced human keratinocytes (HaCaT).

MATERIALS AND METHODS

Before utilization, Cs-EE was dissolved in dimethyl sulfoxide (DMSO) and was preserved at a temperature of -20 °C. The phytochemical constituents of Cs-EE were detected by gas chromatography-mass spectrometry analysis (GC-MS). Sequentially, HaCaT cells were exposed to varying concentrations of Cs-EE prior to ultraviolet B (UVB) irradiation. Evaluations of cellular responses in HaCaT cells, including assessments of cell viability, deoxyribonucleic acid (DNA) damage, and gene and protein expressions, were carried out. To explore the specific signaling pathway involved, we conducted a luciferase assay in addition to validating these pathways using Western blot analysis.

RESULTS

Nitric oxide (NO) and intracellular reactive oxygen species were decreased. Melanin production through the activation of melanocytes by α-melanocyte-stimulating hormone (MSH) was also inhibited by Cs-EE. Furthermore, the mRNA expression levels of key factors such as cyclooxygenase-2 (COX-2), tumor necrosis factor-α (TNF-α), interleukin 6 (IL-6), MMP-1, MMP-3, and MMP-9 exhibited a remarkable decrease. In addition, the phosphorylation of TAK1 within the signaling cascade exhibited a decline, and the activities of the transcription factor AP-1 were decreased according to a luciferase reporter assay.

CONCLUSIONS

Taken together, these findings suggest that the anti-inflammatory, anti-aging, and anti-apoptotic effects of Cs-EE indicate the compound's potential usefulness as a natural component in pharmaceutical and cosmetic products.

Extracellular vesicles derived from mesenchymal stem cells: the wine in Hebe's hands to treat skin aging

Owing to its constant exposure to the external environment and various stimuli, skin ranks among the organs most vulnerable to manifestations of aging. Preventing and delaying skin aging has become one of the prominent research subjects in recent years. Mesenchymal stem cells (MSCs) are multipotent stem cells derived from mesoderm with high self-renewal ability and multilineage differentiation potential. MSC-derived extracellular vesicles (MSC-EVs) are nanoscale biological vesicles that facilitate intercellular communication and regulate biological behavior. Recent studies have shown that MSC-EVs have potential applications in anti-aging therapy due to their anti-inflammatory, anti-oxidative stress, and wound healing promoting abilities. This review presents the latest progress of MSC-EVs in delaying skin aging. It mainly includes the MSC-EVs promoting the proliferation and migration of keratinocytes and fibroblasts, reducing the expression of matrix metalloproteinases, resisting oxidative stress, and regulating inflammation. We then briefly discuss the recently discovered treatment methods of MSC-EVs in the field of skin anti-aging. Moreover, the advantages and limitations of EV-based treatments are also presented.

Relation Between Reactive Oxygen Species Production and Transient Receptor Potential Vanilloid1 Expression in Human Skin During Aging

Skin sensitivity and impaired epidermal barrier function are associated with aging and are at least partly due to increased production of reactive oxygen species (ROS). Transient receptor potential vanilloid1 (TRPV1) is expressed in keratinocytes, fibroblasts, mast cells, and endothelial cells in skin. We investigated in skin biopsies of adult and elderly donors whether TRPV1 expression is involved in the skin aging process. We found that aging skin showed a strongly reduced epidermal thickness, strongly increased oxidative stress, protease expression, and mast cell degranulation and strongly increased TRPV1 expression both in epidermis and dermis. Based on our findings, the aging-related changes observed in the epidermis of the skin level are associated with increased ROS production, and hypothesized alterations in TRPV1 expression are mechanistically linked to this process.

Lipocalin 2 (LCN2) confers acquired resistance to almonertinib in NSCLC through LCN2-MMP-9 signaling pathway

Almonertinib, a third-generation epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor, is highly selective for EGFR-activating mutations as well as the EGFR T790M mutation in patients with advanced non-small cell lung cancer (NSCLC). However, the development of resistance inevitably occurs and poses a major obstacle to the clinical efficacy of almonertinib. Therefore, a clear understanding of the mechanism is of great significance to overcome drug resistance to almonertinib in the future. In this study, NCI-H1975 cell lines resistant to almonertinib (NCI-H1975 AR) were developed by concentration-increasing induction and were employed for clarification of underlying mechanisms of acquired resistance. Through RNA-seq analysis, the HIF-1 and TGF-β signaling pathways were significantly enriched by gene set enrichment analysis. Lipocalin-2 (LCN2), as the core node in these two signaling pathways, were found to be positively correlated to almonertinib-resistance in NSCLC cells. The function of LCN2 in the drug resistance of almonertinib was investigated through knockdown and overexpression assays in vitro and in vivo. Moreover, matrix metalloproteinases-9 (MMP-9) was further identified as a critical downstream effector of LCN2 signaling, which is regulated via the LCN2-MMP-9 axis. Pharmacological inhibition of MMP-9 could overcome resistance to almonertinib, as evidenced in both in vitro and in vivo models. Our findings suggest that LCN2 was a crucial regulator for conferring almonertinib-resistance in NSCLC and demonstrate the potential utility of targeting the LCN2-MMP-9 axis for clinical treatment of almonertinib-resistant lung adenocarcinoma.

Evaluation of the anti-aging effects of Zinc-α2-glycoprotein peptide in clinical and in vitro study

BACKGROUND

Skin aging, characterized by the deterioration of skin density and elasticity, is a common concern among individuals seeking to maintain a youthful appearance. Zinc-α2-glycoprotein (ZAG) is secreted by various body fluids, and is associated with lipolysis and identified as an atopic dermatitis biomarker. This study evaluated the potential of ZAG peptides, which exert multiple benefits such as anti-aging.

MATERIALS AND METHODS

We conducted a 4-week clinical trial on patients with noticeable periorbital wrinkles (n = 22) using a ZAG peptide-containing product. The effects of the products on skin density, elasticity, and the depth of periorbital wrinkles were evaluated using Cutometer Dual MPA580, Ultrascan, and Antera 3D CS, respectively. The effect of ZAG peptides on UVB-treated keratinocyte cells was evaluated in vitro to understand the mechanisms underlying its effects against impaired skin barrier function, collagen degradation, and senescence. In addition, the effects of ZAG peptides on cell viability and expression of aging and skin barrier-related genes were assessed using cell counting kit assay and quantitative reverse transcription-polymerase chain reaction, respectively.

RESULTS

The patients demonstrated improved skin density, elasticity, and reduced periorbital wrinkles. Further, more than 85% patients scored the product as satisfactory regarding anti-aging effects. Furthermore, ZAG peptides reduced SA-β-gal staining, downregulated the senescence-related genes, and upregulated the skin barrier function-related genes in UVB-irradiated keratinocyte cells.

CONCLUSIONS

Our clinical and in vitro findings showed that ZAG peptides exert anti-aging effects and improve skin barrier functions, suggesting their promising potential as therapeutic agents to combat skin aging and improve skin health.

Oral intake of collagen hydrolysate from mackerel scad (Decapterus macarellus) attenuates skin photoaging by suppressing the UVB-induced expression of MMP-1 and IL-6

OBJECTIVES

Excessive skin exposure to UVB radiation can induce photoaging caused by an imbalance in oxidative stress and inflammatory responses, damaging the skin's structure and surface layer. A previous study revealed that collagen hydrolisate extracted from the skin of mackarel scads (Decapterus macarellus) had antiaging properties that were tested in vitro, which serves as a foundation for a subsequent study of its use in vivo. This study aimed at investigating the repair effect of the mackerel scad's skin collagen hydrolysate (MSS-CH) in photoaging conditions in a mouse model.

METHODS

MSS-CH was given orally in mice model of skin photoaging under chronic exposure to UVB irradiation for 12 weeks. Morphological and histological changes on the skin were evaluated using SEM and HE staining, along with the measurement of the expression of matrix metalloproteinases (MMP-1) and cytokine pro-inflammatory interleukin 6 (IL-6) using ELISA.

RESULTS

MSS-CH inhibits the occurrence of epidermal thickening and damage to the dermal layer of the skin. As a result, it restores the epidermis' barrier function and reduces surface damage caused by photoaging. The skin of the MSS-CH treated group exhibited improved physical appearance with reduced fine lines, wrinkles, and enhanced smoothness. Additionally, administering MSS-CH to the mice groups reduced the expression of MMP-1 and IL-6 in UVB-exposed skin.

CONCLUSIONS

Altogether, this in vivo study demonstrates the photoaging-protective properties of CH-MSS, aligning with previous in vitro data. Thus, MSS-CH emerges as a strong candidate for use as an ingredient in nutraceuticals and biocosmetics.

Ultraviolet Radiation Biological and Medical Implications

Ultraviolet (UV) radiation plays a crucial role in the development of melanoma and non-melanoma skin cancers. The types of UV radiation are differentiated by wavelength: UVA (315 to 400 nm), UVB (280 to 320 nm), and UVC (100 to 280 nm). UV radiation can cause direct DNA damage in the forms of cyclobutane pyrimidine dimers (CPDs) and 6-4 photoproducts (6-4PPs). In addition, UV radiation can also cause DNA damage indirectly through photosensitization reactions caused by reactive oxygen species (ROS), which manifest as 8-hydroxy-2'-deoxyguanine (8-OHdG). Both direct and indirect DNA damage can lead to mutations in genes that promote the development of skin cancers. The development of melanoma is largely influenced by the signaling of the melanocortin one receptor (MC1R), which plays an essential role in the synthesis of melanin in the skin. UV-induced mutations in the BRAF and NRAS genes are also significant risk factors in melanoma development. UV radiation plays a significant role in basal cell carcinoma (BCC) development by causing mutations in the Hedgehog (Hh) pathway, which dysregulates cell proliferation and survival. UV radiation can also induce the development of squamous cell carcinoma via mutations in the TP53 gene and upregulation of MMPs in the stroma layer of the skin.

miR-146a is a critical target associated with multiple biological pathways of skin aging

Introduction: The skin is the largest organ of the human body and fulfills protective, immune, and metabolic functions. Skin function and barrier integrity are actively regulated through circadian rhythm-associated genes and epigenetic mechanisms including DNA methylation/demethylation, histone acetylation/deacetylation, and microRNAs. MicroRNA-146a-5p (miR-146a) has been associated with immune activation and skin inflammation; however, the role of miR-146a in regulating skin aging is an open question. This study investigated the role of miR-146a in fibroblasts obtained from different donors in the context of aging, and a potential association of this miRNA with circadian rhythm. Methods: Normal human dermal fibroblasts (NHDFs) from 19y, 27y, 40y, and 62y old donors were used to analyze for miR-146a expression. Expression of miR-146a was downregulated with the hsa-mirVana miR-146a inhibitor, and upregulated with an extract from Adansonia digitata. Effects on markers of skin aging, including cell proliferation, production of Collagen-1 and inflammatory cytokines were assessed. Results: We show that the expression of miR-146a decreases with age in dermal fibroblasts and inhibition of miR-146a in 19y and 62y old NHDFs induced significant changes in essential clock genes indicating an association with circadian rhythm control. Furthermore, downregulation of miR-146a results in a reduction of cellular proliferation, Collagen-1 production, as well as an increase in DNA damage and pro-inflammatory markers. Activation of miR-146a with the Adansonia digitata extract reduced the deleterious effects seen during miR-146a inhibition and increased miR-146a transport through exosome transfer. Conclusion: miR-146a interacts with multiple biological pathways related to skin aging, including circadian rhythm machinery, cell-to-cell communication, cell damage repair, cell proliferation, and collagen production and represents a promising target to fight skin aging. Adansonia digitata extract can promote miR-146a expression and therefore support skin cells' health.

Magnolin targeting of the JNK/Sp1/MMP15 signaling axis suppresses cervical cancer microenvironment and metastasis via microbiota modulation

Magnolin (MGL), a compound derived from the magnolia plant, has inhibitory effects on tumor cell invasion and growth. His study aims to explore the antitumor effect and underlying molecular mechanism of MGL against human cervical cancer. We found that MGL inhibited the proliferation, migration, and invasiveness of cervical cancer cells in vitro and in vivo. The underlying mechanism was shown to involve MGL-induced inhibition of JNK/Sp1-mediated MMP15 transcription and translation. Overexpression of JNK/Sp1 resulted in significant restoration of MMP15 expression and the migration and invasion capabilities of MGL-treated cervical cancer cells. MGL modulated the cervical cancer microenvironment by inhibiting cell metastasis via targeting IL-10/IL-10 receptor B (IL-10RB) expression, thereby attenuating JNK/Sp1-mediated MMP15 expression. Analysis of the gut microbiota of mice fed MGL revealed a significant augmentation in Lachnospiraceae bacteria, known for their production of sodium butyrate. In vivo experiments also demonstrated synergistic inhibition of cervical cancer cell metastasis by MGL and sodium butyrate co-administration. Our study provides pioneering evidence of a novel mechanism by which MGL inhibits tumor growth and metastasis through the IL-10/IL-10RB targeting of the JNK/Sp1/MMP15 axis in human cervical cancer cells.

Laboratory Assessment of the Effects of AGA@4life Multidisciplinary Intervention on the Inflammatory Profile, MMPs, and TIMPs in a Geriatric Population

In recent years, the world's aging population has increased, contributing to the development of age-related pathologies, which have been aggravated by physical inactivity and excessive fat intake. This study aimed to evaluate the effect of implementing a nutritional program (control group-CG) combined with exercise (intervention group-IG) on the inflammatory profile, MMPs, and TIMPs in a group of 34 elderly participants (IG, n = 18; CG, n = 16). Participants underwent a full multidisciplinary diagnostic evaluation (T0), with the gathering of clinical information and biochemical and hematological determinations being re-evaluated eight weeks later (T1). A diet manual was made, which provided a selection of different types of diets resulting from the nutritional needs of the different users at the center. The aerobic exercise consisted of two sessions per week with a total duration of 1 h. The laboratory evaluation was performed by slot blot. Statistical analysis included a paired sample t-test and Spearman's correlation coefficient. We observed that in the IG, there was a significant increase at T1 of TNF-α (p < 0.05) and MMP-2 (p < 0.05), without changes in IL-6 and MMP-9, showing that the intervention did not cause an exacerbated inflammatory response in exercised elderly people. The intervention program implemented showed potential to contribute to better active aging strategies, taking advantage of the known benefits of exercise without inducing a harmful inflammatory response in elderly participants.

Antiaging effects of a skin care formulation containing nanoencapsulated antioxidants: A clinical, in vitro, and ex vivo study

BACKGROUND

The development of effective cosmetic products for the reduction of the signs of skin aging is a complex process which requires an optimized combination of ingredients and specialized systems to deliver the actives to the skin layers.

AIM

To evaluate the tolerance and antiaging clinical efficacy of a cosmetic formulation containing a blend of nanoencapsulated antioxidants: ascorbyl palmitate, resveratrol, tocopherol, caffeine, carnosine, and niacinamide.

METHODS

Clinical efficacy was determined by subjective and instrumental analyses of collagen synthesis by fluorescence spectroscopy, by three-dimensional imaging analysis of suborbital edema, and by analysis of skin hydration and sebum content by biophysical techniques-Corneometer® and Sebumeter®.

RESULTS

The studied formulation was safe and effective for the improvement of skin appearance by increasing collagen synthesis and skin moisturizing and by reducing facial blemishes, swelling, and oiliness. A preclinical exploratory approach using an experimental model of human cell and skin cultures agreed with the observed antiaging effects, identifying mechanisms related to the containment of oxidative stress, reduction of melanin production, increased synthesis of type I procollagen, and regulation of the epidermal cohesion protein filaggrin.

CONCLUSIONS

The skin benefits obtained resulted from the combination of the ingredients in the formulation and the nanoencapsulation-based delivery system, which favors the solubility, safety, efficacy, and bioavailability of the preparation to the skin.

Exploring the Safety and Efficacy of Organic Light-Emitting Diode in Skin Rejuvenation and Wound Healing

PURPOSE

Photobiomodulation (PBM), encompassing low-energy laser treatment and light-emitting diode (LED) phototherapy, has demonstrated positive impacts on skin rejuvenation and wound healing. Organic light-emitting diodes (OLEDs) present a promising advancement as wearable light sources for PBM. However, the biological and biochemical substantiation of their skin rejuvenation and wound healing effects remains limited. This study aimed to ascertain the safety and efficacy of OLEDs as a next-generation PBM modality through comprehensive in vitro and in vivo investigations.

MATERIALS AND METHODS

Cell viability assays and human ex vivo skin analyses were performed after exposure to OLED and LED irradiation to examine their safety. Subsequent evaluations examined expression levels and wound healing effects in human dermal fibroblasts (HDFs) using quantitative reverse transcription-polymerase chain reaction, enzyme-linked immunosorbent assay, and wound healing assays post-irradiation. Additionally, an in vivo study was conducted using a ultra violet (UV)-irradiated animal skin model to explore the impact of OLED exposure on dermal collagen density and wrinkles, employing skin replica and tissue staining techniques.

RESULTS

OLED irradiation had no significant morphological effects on human skin tissue, but caused a considerably higher expression of collagen than the control and LED-treated groups. Moreover, OLED irradiation reduced the expression levels of matrix metalloproteinases (MMPs) more effectively than did LED on HDFs. OLED irradiation group in HDFs had significantly higher expression levels of growth factors compared to the control group, but similar to those in the LED irradiation group. In addition, OLED irradiation on photo-aged animal skin model resulted in increased collagen fiber density in the dermis while reducing ultra violet radiation-mediated skin wrinkles and roughness, as shown in the skin replica.

CONCLUSION

This study established comparable effectiveness between OLED and LED irradiation in upregulating collagen and growth factor expression levels while downregulating MMP levels in vitro. In the UV-irradiated animal skin model, OLED exposure post UV radiation correlated with reduced skin wrinkles and augmented dermal collagen density. Accelerated wound recovery and demonstrated safety further underscore OLEDs' potential as a future PBM modality alongside LEDs, offering promise in the realms of skin rejuvenation and wound healing.

Doxercalciferol alleviates UVB-induced HaCaT cell senescence and skin photoaging

Prolonged or excessive ultraviolet (UV) exposure can lead to premature skin aging. Doxercalciferol (Dox), an analog of vitamin D2, is chiefly used to treat endocrine diseases, cardiovascular diseases, kidney diseases, etc. To date, research on Dox in alleviating photoaging and UV-induced inflammation is scarce. In this research, we evaluated the function of Dox in ultraviolet radiation B (UVB)-induced photoaging and explored the potential mechanism in human keratinocytes (Hacat) and BALB/c mice. First, we established a stable UVB-induced photoaging cell model. Then, we found that the senescence β-galactosidase (SA-β-Gal) positive rate, senescence-related protein (p16), aging-related genes (p21 and p53), senescence-associated secretory phenotype (SASP), inflammatory driving factors (IL-1β and IL-6) and matrix metalloproteinases (MMPs) (MMP1 and MMP9) were upregulated in HaCaT cells after UVB irradiation. At the same time, the effect of UVB on the back skin of BALB/c mice showed a consistent trend. Dox effectively alleviated the aforementioned changes caused by UVB radiation. Mechanistically, we found that UVB activated mitogen-activated protein kinase (MAPK) and nuclear factor kappa B (NF-κB) signaling pathways, and Dox inhibited UVB-activated NF-κB and MAPK. Furthermore, Dox inhibited UVB-induced skin photoaging and damage in mice. In summary, Dox has been improved to inhibit photoaging, which may help to develop therapies to delay skin photoaging.

Hesperetin activates CISD2 to attenuate senescence in human keratinocytes from an older person and rejuvenates naturally aged skin in mice

BACKGROUND

CDGSH iron-sulfur domain-containing protein 2 (CISD2), a pro-longevity gene, mediates healthspan in mammals. CISD2 is down-regulated during aging. Furthermore, a persistently high level of CISD2 promotes longevity and ameliorates an age-related skin phenotype in transgenic mice. Here we translate the genetic evidence into a pharmaceutical application using a potent CISD2 activator, hesperetin, which enhances CISD2 expression in HEK001 human keratinocytes from an older person. We also treated naturally aged mice in order to study the activator's anti-aging efficacy.

METHODS

We studied the biological effects of hesperetin on aging skin using, firstly, a cell-based platform, namely a HEK001 human keratinocyte cell line established from an older person. Secondly, we used a mouse model, namely old mice at 21-month old. In the latter case, we investigate the anti-aging efficacy of hesperetin on ultraviolet B (UVB)-induced photoaging and naturally aged skin. Furthermore, to identify the underlying mechanisms and potential biological pathways involved in this process we carried out transcriptomic analysis. Finally, CISD2 knockdown HEK001 keratinocytes and Cisd2 knockout mice were used to study the Cisd2-dependent effects of hesperetin on skin aging.

RESULTS

Four findings are pinpointed. Firstly, in human skin, CISD2 is mainly expressed in proliferating keratinocytes from the epidermal basal layer and, furthermore, CISD2 is down-regulated in the sun-exposed epidermis. Secondly, in HEK001 human keratinocytes from an older person, hesperetin enhances mitochondrial function and protects against reactive oxygen species-induced oxidative stress via increased CISD2 expression; this enhancement is CISD2-dependent. Additionally, hesperetin alleviates UVB-induced damage and suppresses matrix metalloproteinase-1 expression, the latter being a major indicator of UVB-induced damage in keratinocytes. Thirdly, transcriptomic analysis revealed that hesperetin modulates a panel of differentially expressed genes that are associated with mitochondrial function, redox homeostasis, keratinocyte function, and inflammation in order to attenuate senescence. Intriguingly, hesperetin activates two known longevity-associated regulators, namely FOXO3a and FOXM1, in order to suppress the senescence-associated secretory phenotype. Finally, in mouse skin, hesperetin enhances CISD2 expression to ameliorate UVB-induced photoaging and this occurs via a mechanism involving CISD2. Most strikingly, late-life treatment with hesperetin started at 21-month old and lasting for 5 months, is able to retard skin aging and rejuvenate naturally aged skin in mice.

CONCLUSIONS

Our results reveal that a pharmacological elevation of CISD2 expression at a late-life stage using hesperetin treatment is a feasible approach to effectively mitigating both intrinsic and extrinsic skin aging and that hesperetin could act as a functional food or as a skincare product for fighting skin aging.

A Panel of Potential Serum Markers Related to Angiogenesis, Antioxidant Defense and Hypoxia for Differentiating Cutaneous Squamous Cell Carcinomas from Actinic Keratoses

Cutaneous squamous cell carcinoma (cSCC) arising from the malignant proliferation of epidermal keratinocytes is the second most common skin cancer. Actinic keratosis (AK), which is considered cSCC in situ, may progress into invasive tumors. Currently, there are no serum markers that can differentiate cSCC from AK. The aim of our study was to assess angiogenesis and oxidative stress in patients with cSCC and patients with AK and find reliable serum markers useful in the diagnosis of cSCC. We have determined the serum levels of a group of proangiogenic factors (MMP-2, MMP-9, VEGF, FGF2), the total antioxidative status/capacity (TAS/TAC), ImAnOx, a marker of oxidative stress, and HIF-1 alpha, an indicator of hypoxia. We have identified higher serum levels of MMP-2. MMP-9, VEGF, FGF2 and HIF-1 alpha and lower levels of ImAnOx in cSCC patients compared to AK patients and controls. There were no statistically significant differences between AK patients and controls. We have found positive correlations between proangiogenic markers and HIF-1 alpha and negative correlations between proangiogenic markers and ImAnOx. Our results suggest that MMP-2, MMP-9, VEGF, FGF2, ImAnOx and HIF-1 may be promising markers for differentiating AK from cSCC, and there is a link between angiogenesis, oxidative stress and hypoxia.

Ethosomes for Curcumin and Piperine Cutaneous Delivery to Prevent Environmental-Stressor-Induced Skin Damage

Diesel particulate matter is one of the most dangerous environmental stressors affecting human health. Many plant-derived compounds with antioxidant and anti-inflammatory properties have been proposed to protect the skin from pollution damage. Curcumin (CUR) has a plethora of pharmacological activities, including anticancer, antimicrobial, anti-inflammatory and antioxidant. However, it has low bioavailability due to its difficult absorption and rapid metabolism and elimination. CUR encapsulation in nanotechnological systems and its combination with biopotentiators such as piperine (PIP) can improve its pharmacokinetics, stability and activity. In this study, ethosomes (ETs) were investigated for CUR and PIP delivery to protect the skin from damage induced by diesel particulate matter. ETs were produced by different strategies and characterized for their size distribution by photon correlation spectroscopy, for their morphology by transmission electron microscopy, and for their drug encapsulation efficiency by high-performance liquid chromatography. Franz cells enabled us to evaluate in vitro the drug diffusion from ETs. The results highlighted that ETs can promote the skin permeation of curcumin. The studies carried out on their antioxidant activity demonstrated an increase in the antioxidant power of CUR using a combination of CUR and PIP separately loaded in ETs, suggesting their possible application for the prevention of skin damage due to exogenous stressors. Ex vivo studies on human skin explants have shown the suitability of drug-loaded ETs to prevent the structural damage to the skin induced by diesel engine exhaust exposure.

Enzymatically modified isoquercitrin and its protective effects against photoaging: In-vitro and clinical studies

This research examines the anti-aging potential of the flavonoid derivative of isoquercitrin known as enzymatically modified isoquercitrin (EMIQ). Initial HPLC analyses showed that EMIQ used in the study contained 1-12 glucosides and 10.7% pentahydroxyflavonoids, promising potent antioxidant properties. In subsequent in-vitro studies with UVA-exposed human dermal fibroblasts (HDFa), EMIQ demonstrated protective properties by reducing collagen damage. It modulated both the TGFβ/Smad pathway and the MMP1 pathway, contributing to collagen preservation. This protective effect was further confirmed using the T-Skin™ model, a reconstructed full-thickness human skin model, which illustrated that EMIQ could defend the physiological structures of both the epidermis and dermis against UV radiation. A 28-day clinical trial with 30 volunteers aged 31-55 years highlighted EMIQ's effectiveness. Participants using EMIQ-containing Essence displayed reduced facial trans-epidermal water loss and skin roughness, alongside improved skin elasticity. This study emphasizes EMIQ's potential as an anti-photoaging ingredient in cosmetics, warranting further research. The findings pave the way for developing innovative skincare products addressing photoaging effects.

Rapamycin protects mouse skin from ultraviolet B-induced photodamage by modulating Hspb2-mediated autophagy and apoptosis

BACKGROUND

Continuous exposure to UVB is the main extrinsic cause of skin photodamage, which is associated with oxidative stress, DNA damage, apoptosis and degradation of collagen. Rapamycin, a mechanistic target inhibitor of rapamycin complex 1 (mTORC1), has been shown to play a crucial role anti-tumor and aging retardation, but its mechanism of action in UVB-induced photodamage still remains unknown. In this study, we investigated the role of rapamycin and Hspb2 (also known as Hsp27) in UVB-induced photodamage in mice.

METHODS AND RESULTS

We constructed skin acute photodamage models on the ears of WT and Hspb2 KO mice, respectively, and administered rapamycin treatment. Histological results showed that knockout of the hspb2 exacerbated the skin damage, as evidenced by thickening of the epidermis, breakage and disruption of collagen fibers and reduction in their number, which is reversed by rapamycin treatment. In addition, hspb2 knockout promoted UVB-induced apoptosis and reduced autophagy levels, with a significant increase in p53 levels and Bax/Bcl-2 ratio, a reduction in LC3II/I ratio and an increase in p62 levels in the KO mice compared to those in WT mice after the same dose of UVB irradiation. Rapamycin was also found to inhibit collagen degradation induced by hspb2 knockdown through activation of the TGF-β/Smad signaling pathway.

CONCLUSIONS

Rapamycin can alleviate skin photodamage from Hspb2 knockout to some extent. It may be a potential therapeutic drug for skin photodamage. In this study, we investigated the role of rapamycin and Hspb2 in UVB-induced photodamage in mice. Histological results showed that knockout of the hspb2 exacerbated the skin damage, as evidenced by thickening of the epidermis, breakage and disruption of collagen fibers and reduction in their number, which is reversed by rapamycin treatment. In addition, hspb2 knockout promoted UVB-induced apoptosis and reduced autophagy levels. Rapamycin was also found to inhibit collagen degradation induced by hspb2 knockdown through activation of the TGF-β/Smad signaling pathway. We conclude that rapamycin and Hspb2 exert a synergistic protective effect in skin photodamage.

Q-switched 1064 nm Nd: YAG laser restores skin photoageing by activating autophagy by TGFβ1 and ITGB1

Excessive ultraviolet B ray (UVB) exposure to sunlight results in skin photoageing. Our previous research showed that a Q-switched 1064 nm Nd: YAG laser can alleviate skin barrier damage through miR-24-3p. However, the role of autophagy in the laser treatment of skin photoageing is still unclear. This study aims to investigate whether autophagy is involved in the mechanism of Q-switched 1064 nm Nd: YAG in the treatment of skin ageing. In vitro, primary human dermal fibroblast (HDF) cells were irradiated with different doses of UVB to establish a cell model of skin photoageing. In vivo, SKH-1 hairless mice were irradiated with UVB to establish a skin photoageing mouse model and irradiated with laser. The oxidative stress and autophagy levels were detected by western blot, immunofluorescence and flow cytometer. String was used to predict the interaction protein of TGF-β1, and CO-IP and GST-pull down were used to detect the binding relationship between TGFβ1 and ITGB1. In vitro, UVB irradiation reduced HDF cell viability, arrested cell cycle, induced cell senescence and oxidative stress compared with the control group. Laser treatment reversed cell viability, senescence and oxidative stress induced by UVB irradiation and activated autophagy. Autophagy agonists or inhibitors can enhance or attenuate the changes induced by laser treatment, respectively. In vivo, UVB irradiation caused hyperkeratosis, dermis destruction, collagen fibres reduction, increased cellular senescence and activation of oxidative stress in hairless mice. Laser treatment thinned the stratum corneum of skin tissue, increased collagen synthesis and autophagy in the dermis, and decreased the level of oxidative stress. Autophagy agonist rapamycin and autophagy inhibitor 3-methyladenine (3-MA) can enhance or attenuate the effects of laser treatment on the skin, respectively. Also, we identified a direct interaction between TGFB1 and ITGB1 and participated in laser irradiation-activated autophagy, thereby inhibiting UVB-mediated oxidative stress further reducing skin ageing. Q-switched 1064 nm Nd: YAG laser treatment inhibited UVB-induced oxidative stress and restored skin photoageing by activating autophagy, and TGFβ1 and ITGB1 directly incorporated and participated in this process.

Potential antiaging activity of secretome gel of human Wharton's jelly mesenchymal stem cells (hWJ-MSCs) in UV-induced mice models

Objectives

Skin aging is a degenerative process that can be induced by UV irradiation. UV radiation can produce reactive oxidate stress which causes premature aging. This study aims to examine the antiaging potential of secretome gel (SC) from human Wharton Jelly Mesenchymal Stem Cells (hWJ-MSCs) in a UVB-induced mice model.

Materials and Methods

The secretome was obtained from hWJ-MSCs and made in gel form. Male mice were radiated by UVB for 15 min twice daily for 14 days. The gel was topically applied to the mice's dorsal skin. Two treatments of secretome gel: secretome 1 is applied once and secretome 2 is applied twice daily after UVB radiation. TGF-β1, IL-10, and IL-18 gene expression was determined using RT-PCR. Hematoxylin Eosin staining was used to observe the inflammation and collagen density of skin tissue. An immunohistochemistry assay was used to analyze the protein expression of P53, COL4A1, MMP-2, and MMP-13. The data were statistically analyzed using the ANOVA test followed by the Tukey post hoc test (P<0.05).

Results

UVB induction caused loss of collagen, increasing inflammation and high expression of aging mediators. SC increased the gene expression of TGF-β1 and IL-10 and decreased IL-18 gene expression. Histopathological tests showed that SG increased collagen density, lowered inflammation, and repaired cell damage in skin tissue. Immunohistochemistry test showed that SC decreased MMP-2, MMP-13, and P53 expression, in contrast, increased COL4A1.

Conclusion

The secretome gel of hWJ-MSCs showed antiaging activities with potential for preventing and curing skin aging.

MMP1, MMP9, MMP11 and MMP13 in melanoma and its metastasis - key points in understanding the mechanisms and celerity of tumor dissemination

BACKGROUND

Matrix metalloproteinase (MMP)1, MMP9, MMP11, and MMP13 are overexpressed in malignant melanoma (MM), being associated with tumor invasive phase, metastases, and more aggressive neoplastic phenotypes.

AIM

The main objective of the current study was to correlate the expression of the MMPs with the evolution of MM toward distant metastasis.

PATIENTS, MATERIALS AND METHODS

We designed a retrospective cohort study, including 13 patients with metastatic MM. Data concerning age, sex, localization of the primary lesion and metastasis, and histological and immunohistochemical features (intensity of expression and percent of positive cells for MMPs) were statistically processed.

RESULTS

The time between the diagnosis of primitive melanoma and the diagnosis of metastasis ranged between 0 and 73 months, with a mean value of 18.3 months. The metastases rich in MMP1- and MMP9-positive cells occurred earlier than the metastases with low levels of positive cells. The mean period until metastasis was shorter for the MMP1-expressing tumors than the ones without MMP1 expression. MMP13 expression in the tumor and its metastasis was significantly linked with the time until the metastasis occurrence.

CONCLUSIONS

This study emphasizes the roles of MMP1, MMP9, and MMP13 in the process of metastasis in melanoma and the opportunity to use them as therapeutic targets and surveillance molecules.

Sesamin attenuates UVA-induced keratinocyte injury via inhibiting ASK-1-JNK/p38 MAPK pathways

BACKGROUND

Ultraviolet (UV) exposure-stimulated reactive oxygen species (ROS) formation in keratinocytes is a crucial factor in skin aging. Phytochemicals have become widely popular for protecting the skin from UV-induced cell injury. Sesamin (SSM) has been shown to play a role in extensive pharmacological activity and exhibit photoprotective effects.

AIM

To assess the protective effect of SSM on UVA-irradiated keratinocytes and determine its potential antiphotoaging effect.

METHODS

HaCaT keratinocytes pretreated with SSM were exposed to UVA radiation at 8 J/cm2 for 10 min. Cell viability and oxidative stress indicators were evaluated using a cell counting kit-8 and lactate dehydrogenase (LDH), malondialdehyde (MDA), glutathione (GSH), and superoxide dismutase (SOD) assay kits. Apoptosis and intracellular ROS levels were analyzed using annexin V-fluorescein isothiocyanate/propyridine iodide and dichlorodihydrofluorescein diacetate staining, respectively. Protein levels of matrix metalloprotein-1 (MMP-1), MMP-9, Bax/Bcl-2, and mitogen-activated protein kinase (MAPK) pathway proteins, phospho-apoptosis signal-regulating kinase-1 (p-ASK-1)/ASK-1, phospho-c-Jun N-terminal protein kinase (p-JNK)/JNK, and p-p38/p38 were determined using western blotting.

RESULTS

Sesamin showed no cytotoxicity until 160 μmol/L on human keratinocytes. Sesamin pretreatment (20 and 40 μM) reversed the suppressed cell viability, increased LDH release and MDA content, decreased cellular antioxidants GSH and SOD, and elevated intracellular ROS levels, which were induced by UVA irradiation. Additionally, SSM inhibited the expression of Bax, MMP-1, and MMP-9 and stimulated Bcl-2 expression. In terms of the regulatory mechanisms, we demonstrated that SSM inhibits the phosphorylation of ASK-1, JNK, and p38.

CONCLUSION

The results suggest that SSM attenuates UVA-induced keratinocyte injury by inhibiting the ASK-1-JNK/p38 MAPK pathways.

Modeling of solar UV-induced photodamage on the hair follicles in human skin organoids

Solar ultraviolet (sUV) exposure is known to cause skin damage. However, the pathological mechanisms of sUV on hair follicles have not been extensively explored. Here, we established a model of sUV-exposed skin and its appendages using human induced pluripotent stem cell-derived skin organoids with planar morphology containing hair follicles. Our model closely recapitulated several symptoms of photodamage, including skin barrier disruption, extracellular matrix degradation, and inflammatory response. Specifically, sUV induced structural damage and catagenic transition in hair follicles. As a potential therapeutic agent for hair follicles, we applied exosomes isolated from human umbilical cord blood-derived mesenchymal stem cells to sUV-exposed organoids. As a result, exosomes effectively alleviated inflammatory responses by inhibiting NF-κB activation, thereby suppressing structural damage and promoting hair follicle regeneration. Ultimately, our model provided a valuable platform to mimic skin diseases, particularly those involving hair follicles, and to evaluate the efficacy and underlying mechanisms of potential therapeutics.

Fermented black ginseng extract prevents UVB-induced inflammation by regulating the nc886-PKR pathway in human keratinocytes

BACKGROUND

Continuous exposure of the skin to ultraviolet B (UVB) rays can cause inflammation and photodamage. In previous studies, we observed that the upregulation of nc886, a noncoding RNA (ncRNA), can alleviate UVB-induced inflammation through suppression of the protein kinase RNA (PKR) pathway. We aim to investigate the effect of fermented black ginseng extract (FBGE), which has been shown to increase the expression of nc886, on UVB-induced inflammation in keratinocytes.

METHODS

To confirm the cytotoxicity of FBGE, MTT assay was performed, and no significant cytotoxicity was found on human keratinocytes. The efficacies of FBGE were assessed through qPCR, Western blotting, and ELISA analysis which confirmed regulation of UVB-induced inflammation.

RESULTS

The analysis results showed that FBGE inhibited the decrease in nc886 expression and the increase in the methylated nc886 caused by UVB. It also prevented the UVB-induced increase of metalloproteinase-9 (MMP-9), metalloproteinase-1 (MMP-1), cyclooxygenase-2 (COX-2), prostaglandin E2 (PGE2), interleukin-8 (IL-8) and tumor necrosis factor-α (TNF-α). Additionally, FBGE suppressed the PKR-MAPK pathways activated by UVB.

CONCLUSION

These results implicate that FBGE can alleviate UVB-induced inflammation through regulation of the nc886-PKR pathway.

The Effects of Helichrysum italicum Extract on the Extracellular Matrix of the Skin

OBJECTIVE

An in-vitro study was performed to investigate the molecular basis of the wound healing and skin protective features of Helichrysum italicum (HI), a medicinal plant from the Mediterranean basin.

MATERIALS AND METHODS

A dermal fibroblast cell line culture was treated with HI hydro-alcoholic extract to detect the gene expression levels of three selected primers: FGF-2, HAS-2 and MMP-9. Cell proliferation assay was performed using a XTT reagent. RNA isolations were carried out from both the extract treated study cell group and the control cell group using a TRI reagent. GAPDH was used as the reference gene. Gene expressions were determined by real time RT-qPCR. The results were represented as 'Target/GAPDH Fold Change'. Statistical evaluation was performed by Student's t test.

RESULTS

HI extract caused statistically significant upregulation of FGF-2 (P=0.0473) and HAS-2 (P=0.0335) gene expressions compared to the untreated control cells. The treatment ended with 1.74 and 3.10 fold changes for FGF-2 and HAS-2, respectively.

CONCLUSION

In general, it may be considered that HI has certain anabolic effects on the extracellular matrix of the skin because of the significant increases it causes in FGF-2 and HAS-2. Therefore, it may have a promising future in anti-aging studies and cosmetic dermatology. The results obtained in this study may also partially explain the molecular basis of the health benefits of HI on skin, including improvement in wound healing, and protection against the detrimental effects of ultraviolet exposure.

A mechanism of melanogenesis mediated by E-cadherin downregulation and its involvement in solar lentigines

OBJECTIVE

Intensive studies have revealed that pleiotropic melanocytic factors are associated with age-spot formation. Dysfunctional keratinocyte differentiation is thought to be an upstream cause of age-spot formation. Although it has been shown that keratinocyte differentiation is mediated by the cell-cell contact factor E-cadherin, its involvement in age-spot formation remains unknown. Thus, to determine the origin of age-spots and an integrated solution for the same, we focused on E-cadherin expression in the present study.

METHODS

First, we assessed the solar lentigines in cutaneous and cultured cells by means of immunofluorescence staining. Following that, keratinocytes treated with siRNAs against E-cadherin were co-cultured with melanocytes, and the secreted factors were identified by means of proteomic analysis of the culture supernatants. We also performed quantitative PCR to assess melanogenesis activity and screen ingredients. For behavioural analysis of melanocytes, we performed time-lapse imaging using confocal laser scanning microscopy.

RESULTS

E-cadherin expression was downregulated in the epidermis of the solar lentigines, suggesting its involvement in age-spot formation. E-cadherin knocked down keratinocytes not only promoted the secretion of melanocytic/inflammatory factors but also increased melanogenesis by upregulating the expression of melanogenesis factors. Furthermore, live-imaging showed that the downregulation of E-cadherin inhibited melanocyte dynamics and accelerated melanin uptake. Finally, we identified Rosa multiflora fruit extract as a solution that can upregulate E-cadherin expression in keratinocytes.

CONCLUSION

Our findings showed that E-cadherin downregulation triggers various downstream melanocytic processes, such as the secretion of melanocytic factors and melanogenesis. Additionally, we showed that the Rosa multiflora fruit extract upregulated E-cadherin expression in keratinocytes.

Synergistic Effect of Madecassoside and Rosmarinic Acid Against Ultraviolet B-Induced Photoaging in Human Skin Fibroblasts

Madecassoside (MD) and rosmarinic acid (RA) are well-known compounds with wound healing and antiaging effects. We demonstrated the synergistic protective activity of the MD-RA combination in Hs68 cells against ultraviolet B (UVB)-induced photoaging. The cell viabilities of MD, RA, and MD-RA combinations at various ratios (9:1, 8:2, 7:3, 6:4, 5:5, 4:6, 3:7, 2:8, and 1:9, v/v) were measured to compare their protective effects against UVB radiation. The synergistic interaction between MD and RA was confirmed using a combination index. The strongest effect of the MD-RA combination was observed at a ratio of 3:7. The combination of MD-RA 3:7 exerted a synergistic effect against UVB-induced changes in cell viability, as well as superoxide dismutase activity, reactive oxygen species, glutathione, catalase activity, and malondialdehyde levels. Moreover, the inhibitory effect of the MD-RA combination (3:7) on matrix metalloproteinases and total collagen production was higher than that of MD or RA alone. These results demonstrated that the MD-RA combination (3:7) generated a strong synergistic effect against UVB-induced photoaging in Hs68 cells. Overall, our results provide scientific evidence to support the development of a new combination therapy for skin protection against UVB-induced photoaging through the synergistic interaction between MD and RA. These natural compounds are promising options for antiaging and skin protection in the cosmetic and pharmaceutical industries.