Biomarkers, oxidative stress and autophagy in skin aging

Food-derived skin-care ingredient as a promising strategy for skin aging: Current knowledge and future perspectives

Skin aging involves complex biochemical reactions and has attracted a growing concern recently. For it, there is a great desire to replace the hazardous and easy-recurring "therapy means" with "daily care" based on some natural and healthy ingredients. According to a novel theory called "homology of cosmetic and food", the safety, efficacy and accessibility of food-derived skin-care ingredients offer an attractive option for combating skin aging, which will be an inevitable trend of dermatology in the future. Ultraviolet (UV) radiation is a major trigger of skin aging. It acts on the skin and generates reactive oxygen species, which causing oxidative stress. More, matrix metalloproteinase and melanin levels are also upregulated by the UV-activated mitogen-activated protein kinase (MAPK) pathway and tyrosinase, respectively, resulting in collagen degradation and melanin deposition in the extracellular matrix. Through the existing studies, the relevant key biomarkers and biochemical pathways can be effectively controlled by skin-care ingredients from animal-derived and plant-derived foods as well as traditional herbs, thus preserving human skin from UV-induced aging in terms of antioxidant, collagen protection and melanin inhibition. To extend their application potential, some carriers represented by nanoliposomes can facilitate the transdermal absorption of food-derived skin-care ingredients by the variation of molecular weight and lipid solubility. The present review will provide an overview of the trigger mechanisms of skin aging, and focus on the molecular biology aspects of food-derived skin-care ingredients in skin matrix and the critical summarize of their research state.

Phytocosmetic potential of Blumea balsamifera oil in mitigating UV-induced photoaging: Evidence from cellular and mouse models

ETHNOPHARMACOLOGICAL RELEVANCE

Blumea balsamifera (L.) DC. (BB), the source of Blumea balsamifera oil (BBO), is an aromatic medicinal plant, renowned for its pharmacological properties and its traditional use in Southeast Asian countries such as China, Thailand, Vietnam, Malaysia, and the Philippines for centuries. Traditionally, BB has been used as a raw herbal medicine for treating various skin conditions like eczema, dermatitis, athlete's foot, and wound healing for skin injuries.

AIM OF THE STUDY

This research aimed to explore the inhibitory effects of BBO on skin aging using two models: in vitro analysis with human dermal fibroblasts (HDF) under UVB-induced stress, and in vivo studies on UVA-induced dorsal skin aging in mice. The study sought to uncover the mechanisms behind BBO's anti-aging effects, specifically, its impact on cellular and tissue responses to UV-induced skin aging.

MATERIALS AND METHODS

We applied doses of 10-20 μL/mL of BBO to HDF cells that had been exposed to UVB radiation to simulate skin aging. We measured cell viability, and levels of reactive oxygen species (ROS), SA-β-gal, pro-inflammatory cytokines, and matrix metalloproteinases (MMPs). In addition, we investigated the involvement of mitogen-activated protein kinases (MAPKs) and nuclear factor kappa B (NF-κB) signaling pathways in mediating the anti-aging effects of BBO. Histopathological and biochemical analyses were conducted in a mouse model to examine the effects of BBO on UV-induced photoaging.

RESULTS

UV exposure accelerated aging, and caused cellular damage and inflammatory responses through ROS-mediated pathways. In HDF cells, BBO treatment countered the UVB-induced senescence, and the recovery of cell viability was correlated to notable reductions in SA-β-gal, ROS, pro-inflammatory cytokines, and MMPs. Mechanistically, the anti-aging effect of BBO was associated with the downregulation of the JNK/NF-κB signaling pathways. In the in vivo mouse model, BBO exhibited protective capabilities against UV-induced photoaging, which were manifested by the enhanced antioxidant enzyme activities and tissue remodeling.

CONCLUSIONS

BBO effectively protects fibroblasts from UV-induced photoaging through the JNK/NF-κB pathway. Recovery from photoaging involves an increase in dermal fibroblasts, alleviation of inflammation, accelerated synthesis of antioxidant enzymes, and slowed degradation of ECM proteins. Overall, BBO enhances the skin's defensive capabilities against oxidative stress, underscoring its potential as a therapeutic agent for oxidative stress-related skin aging.

The molecular mechanisms underlying optical isomer arbutin permeating the skin: The molecular interaction between arbutin and skin components

Arbutin, a typical optical isomer, has garnered widespread acclaim in the whitening cosmetics for its favorable efficacy and safety. However, the molecular mechanisms underlying α-arbutin and β-arbutin permeating across the skin have not elucidated clearly yet. Herein we aimed to unveil how α-arbutin and β-arbutin interacted with keratin or SC lipids, further demonstrating their relationship with their drug permeability. We found that α-arbutin displayed significantly higher drug accumulation into the porcine skin than β-arbutin within 24 h through in vitro permeation test. Moreover, α-arbutin predominantly induced the alternations of secondary structure of amide II during the drug permeation, which was favorable for α-arbutin permeation. On the contrary, β-arbutin exhibited an observable effect on the stretching vibration of SC lipids, possessing a significantly stronger mixing energy, binding energy and compatibility with ceramide (Cer) than that of α-arbutin, which ultimately restricted its permeation. Interestingly, free fatty acids and ceramides of the SC lipids specifically utilized its oxygen atom of carboxyl group to dock the arbutin molecules, enhancing their affinity with β-arbutin, as confirmed by molecular simulation and 13Carbon Nuclear Magnetic Resonance. Nevertheless, a favorable compatibility between α-arbutin and keratin was observed. It was emphasized that the distinct spatial configuration and opposite optical rotation of arbutin was the leading factor impacting the intermolecular force between arbutin and the SC, and resulted in a diverse drug permeation. In cellular and in vivo skin pharmacokinetic studies, α-arbutin also possessed a higher cellular uptake and topical bioavailability than β-arbutin. This study revealed the transdermal permeation mechanisms of optical isomer arbutin at the molecular levels, providing methodological reference for the investigations of permeation behaviors of other isomers with similar spatial configuration.

Wound healing effect of polydeoxyribonucleotide derived from Hibiscus sabdariffa callus via Nrf2 signaling in human keratinocytes

There has been a growing interest in skin recovery in both the medical and cosmetics fields, leading to an increasing number of studies reporting diverse materials being utilized for this purpose. Among them, polydeoxyribonucleotide (PDRN) is known for its efficacy in skin repair processes, while Hibiscus sabdariffa (HS) is recognized for its antioxidant, hypolipidemic, and wound healing properties, including its positive impact on mammalian skin and cells. We hypothesized that these characteristics may have a germane relationship during the healing process. Consequently, we induced calli from HS and then extracted PDRN for use in treating human keratinocytes. PDRN (5 μg/mL) had considerable wound healing effects and wrinkle improvement effects. To confirm its function at the molecular level, we performed real-time polymerase chain reaction, western blotting, and immunocytochemistry. Furthermore, genes related to wound healing (MMP9, Nrf2, KGF, VEGF, SOD2, and AQP3) were significantly upregulated. Additionally, the protein expression of MMP9, AQP3, and CAT, which are closely related to wound healing and antioxidant cascades, was considerably enhanced. Based on cellular morphology and molecular-level evidence, we propose that PDRN from calli of HS can improve wound healing in human keratinocytes. Furthermore, its potential to serve as a novel material in cosmetic products is demonstrated.

Rapamycin Attenuates H2O2-Induced Oxidative Stress-Related Senescence in Human Skin Fibroblasts

BACKGROUND

Oxidative stress plays an important role in the skin aging process. Rapamycin has been shown to have anti-aging effects, but its role in oxidative senescence of skin cells remains unclear. The aim of this study was to explore the effect of rapamycin on oxidative stress-induced skin cell senescence and to illustrate the mechanism.

METHODS

Primary human skin fibroblasts (HSFs) were extracted and a model of H2O2-induced oxidative senescence was constructed, and the effects of rapamycin on their value-added and migratory capacities were detected by CCK-8 and scratch assays. SA-β-gal was utilized to detect senescence, oxidatively closely related factors were also assessed. Gene and protein expressions of senescence, oxidative, and autophagy were detected by western blotting and quantitative-PCR. The data were analyzed by one-way analysis of variance.

RESULTS

Rapamycin (0.1 nmol/L for 48 h) promoted the proliferative and migration of H2O2-treated HSFs (p < 0.05), decreased senescent phenotypes SA-β-gal staining and the expression of P53, and MMP-1 proteins, and increased the expression level of COL1A-1 (p < 0.001). Rapamycin also enhanced the activities of SOD and HO-1, and effectively removed intracellular ROS, MDA levels (p < 0.05), in addition, autophagy-related proteins and genes were significantly elevated after rapamycin pretreatment (p < 0.001). Rapamycin upregulated the autophagy pathway to exert its protective effects.

CONCLUSION

Our findings indicate that rapamycin shields HSFs from H2O2-induced oxidative damage, the mechanism is related to the reduction of intracellular peroxidation and upregulation of autophagy pathway. Therefore, rapamycin has the potential to be useful in the investigation and prevention of signs of aging and oxidative stress.

Tailoring biomaterials for skin anti-aging

Skin aging is the phenomenon of degenerative changes in the structure and function of skin tissues over time and is manifested by a gradual loss of skin elasticity and firmness, an increased number of wrinkles, and hyperpigmentation. Skin anti-aging refers to a reduction in the skin aging phenomenon through medical cosmetic technologies. In recent years, new biomaterials have been continuously developed for improving the appearance of the skin through mechanical tissue filling, regulating collagen synthesis and degradation, inhibiting pigmentation, and repairing the skin barrier. This review summarizes the mechanisms associated with skin aging, describes the biomaterials that are commonly used in medical aesthetics and their possible modes of action, and discusses the application strategies of biomaterials in this area. Moreover, the synergistic effects of such biomaterials and other active ingredients, such as stem cells, exosomes, growth factors, and antioxidants, on tissue regeneration and anti-aging are evaluated. Finally, the possible challenges and development prospects of biomaterials in the field of anti-aging are discussed, and novel ideas for future innovations in this area are summarized.

Functional hyaluronic acid microneedles for skin photoaging based on collagen induction and oxidative stress regulation strategies

Photoaging holds remarkable importance for skin health and senescence. Ultraviolet (UV) irradiation results in the disruption of the extracellular matrix (ECM) microenvironment, the degradation of collagen, and the generation of oxidative stress. Traditional hyaluronic acid (HA) exhibits a diminished capacity to stimulate collagen regeneration, and hampered by its poor permeability as a macromolecule, ultimately resulting in constrained therapeutic outcomes for the treatment of photoaging. In this study, HA/PX was prepared by functional modification of HA with sulfonate-rich or phosphatidylcholine-rich polymers, which could complement the loss of ECM and ameliorate the senescence of human fibroblasts (HDFs) and hairless mouse models subjected to UVB-induced photoaging. The results indicate that HA/PX exhibits superior abilities in delaying cellular aging, promoting collagen regeneration, and resisting reactive oxygen species (ROS) compared to HA. Furthermore, HA/PX shows good biocompatibility both in vivo and in vitro, without causing allergic reactions or other adverse effects. We also demonstrated that the transdermal delivery of HA/PX via microneedle arrays (MNs) can significantly mitigate wrinkles and skin damage in photoaged nude mice, and achieve the treatment of skin photoaging by enhancing epidermal thickness, promoting collagen deposition, and reducing oxidative stress. Therefore, our research offers a novel possibility for future anti-aging therapeutic strategies.

Dual-mode detection for the total antioxidant capability of skincare products based on porous CuS@CdS@Au nanoshells

The antioxidants in skincare products play a crucial role in delaying the aging process of the skin. With the growing variety of cosmetic products, it is essential to develop effective methods for measuring their total antioxidant capability (TAC). This study introduces a novel nanoenyzme, CuS@CdS@Au nanoshells (NSs), characterized by porous morphologies and composite materials, which demonstrate remarkable localized surface plasmon resonance (LSPR) effects, thereby enhancing their photocatalytic and photothermal properties. Under 808 nm laser irradiation, these nano-enzymes exhibited superior catalytic ability for TMB oxidation and temperature increases compared to CuS or CuS @Au NSs. The TMB absorption response and temperature increase showed high sensitivity to antioxidants such as ascorbic acid, glutathione, and ferulic acid, enabling the development of a dual-mode detection strategy for quantifying the TAC in skincare products without the need for complex pretreatments. Furthermore, the temperature response-based detection results proved to be more accurate than those derived from absorption response in recovery experiments. This research not only improves the reliability of antioxidant assessments but also provides a valuable tool for quality control in the skincare industry.

Antioxidant Peptides and Protein Hydrolysates from Tilapia: Cellular and In Vivo Evidences for Human Health Benefits

Antioxidant peptides derived from aquatic organisms have attracted tremendous research interest due to their potential applications in human health. Tilapia is one of the most widely farmed aquaculture species globally. The current understanding of tilapia-derived antioxidant peptides is gradually expanding. This review discusses the current knowledge of peptides and protein hydrolysates derived from tilapia muscle, skin, and scales, whose antioxidant capacity has been validated in various cellular and in vivo models. To date, at least 16 peptides and several hydrolysates have been identified from tilapia that protect human and non-human cell models against oxidative injury. Tilapia hydrolysates and peptide mixtures have also shown protective effects in animal models of oxidative stress-associated diseases and exercise-induced oxidative injury and fatigue. The key mechanisms of tilapia hydrolysates and peptide mixtures involve enhancing antioxidant enzyme activities and suppressing radical production. Notably, such hydrolysates also exerted additional in vivo functions, such as anti-inflammatory, anti-diabetic, wound healing, and antiaging properties. Taken together, tilapia-derived antioxidant peptides and hydrolysates represent a valuable source of functional ingredients for applications in functional food, dietary supplements, and therapeutic applications. Continued research into their health benefits is warranted in the future.

Palladium nanocrystals regulates scleral extracellular matrix remodeling in myopic progression by modulating the hypoxia signaling pathway Nrf-2/Ho-1

Myopia represents a widespread global public health concern influenced by a combination of environmental and genetic factors. The prevailing theory explaining myopia development revolves around scleral extracellular matrix (ECM) remodeling, characterized by diminished Type I collagen (Col-1) synthesis and increased degradation, resulting in scleral thinning and eye axis elongation. Existing studies underscore the pivotal role of scleral hypoxia in myopic scleral remodeling. This study investigates the peroxidase-like activity and catalytic performance of octahedral Palladium (Pd) nanocrystals, recognized as nanozymes with antioxidative properties. We explore their potential in reducing oxidative stress and alleviating hypoxia in human scleral fibroblasts (HSF) and examine the associated molecular mechanisms. Our results demonstrate the significant peroxidase-like activity of Pd nanocrystals. Furthermore, we observe a substantial reduction in oxidative stress in HSF under hypoxia, mitigating cellular damage. These effects are linked to alterations in Nrf-2/Ho-1 expression, a pathway associated with hypoxic stress. Importantly, our findings indicate that Pd nanocrystals contribute to attenuated scleral matrix remodeling in myopic guinea pigs, effectively slowing myopia progression. This supports the hypothesis that Pd nanocrystals regulate myopia development by controlling oxidative stress associated with hypoxia. Based on these results, we propose that Pd nanocrystals represent a novel and potential treatment avenue for myopia through the modulation of scleral matrix remodeling. This study introduces innovative ideas and directions for the treatment and prevention of myopia.

Thiostrepton induces oxidative stress, mitochondrial dysfunction and ferroptosis in HaCaT cells

TST has been mainly studied for its anti-tumor proliferation and antimicrobial effects, but not widely used in dermatological diseases. The mechanism of cellular damage by TST in response to H2O2-mediated oxidative stress was investigated in human skin immortalized keratinocytes (HaCaT) as an in vitro model. The findings reveal that TST treatment leads to increased oxidative stress in the cells by reducing levels of superoxide dismutase (SOD), glutathione (GSH), and catalase (CAT). This effect is further supported by an upsurge in the expression of malondialdehyde (MDA, a pivotal marker of lipid peroxidation). Additionally, dysregulation of FoxM1 at both gene and protein levels corroborates its involvement TST associated effects. Analysis of ferroptosis-related genes confirms dysregulation following TST treatment in HaCaT cells. Furthermore, TST treatment exhibits effects on mitochondrial morphology and function, affirming its induction of apoptosis in the cells through heightened oxidative stress due to mitochondrial damage and dysregulation of mitochondrial membrane potential.

γ-Mangosteen, an autophagy enhancer, prevents skin-aging via activating KEAP1/NRF2 signaling and downregulating MAPKs/AP-1/NF-κB-mediated MMPs

BACKGROUND

Mangosteens, a naturally occurring xanthones, found abundantly in mangosteen fruits. The anti-skin aging potential of γ-mangosteen (GM) remains unexplored; therefore, we investigated the UVB-induced anti-skin aging of GM via activation of autophagy.

HYPOTHESIS

We hypothesized that GM exerts antioxidant and anti-aging capabilities both in vitro and in vivo through activation of autophagy as well as control of KEAP1/NRF2 signaling and MAPKs/AP-1/NF-κB-mediated MMPs pathways.

METHODS

The anti-skin aging effects of GM were studied using HDF cells and a mice model. Various assays, such as DPPH, ABTS, CUPRAC, FRAP, and ROS generation, assessed antioxidant activities. Kits measured antioxidant enzymes, SA-β-gal staining, collagen, MDA content, si-RNA experiments, and promoter assays. Western blotting evaluated protein levels of c-Jun, c-Fos, p-IκBα/β, p-NF-κB, MAPK, MMPs, collagenase, elastin, KEAP1, NRF2, HO-1, and autophagy-related proteins.

RESULTS

GM exhibited strong antioxidant, collagenase and elastase enzyme inhibition activity surpassing α- and β-mangosteen. GM competitively inhibited elastase with a Ki value of 29.04 µM. GM orchestrated the KEAP1-NRF2 pathway, enhancing HO-1 expression, and suppressed UVB-induced ROS in HDF cells. NRF2 knockdown compromised GM's antioxidant efficacy, leading to uncontrolled ROS post-UVB. GM bolstered endogenous antioxidants, curbing lipid peroxidation in UVB-exposed HDF cells and BALB/c mice. GM effectively halted UVB-induced cell senescence, and reduced MMP-1/-9, while elevated TIMP-1 levels, augmented COL1A1, ELN, and HAS-2 expression in vitro and in vivo. Additionally, it suppressed UVB-induced MAPKs, AP-1, NF-κB phosphorylation. Pharmacological inhibitors synergistically enhanced GM's anti-skin aging potential. Moreover, GM inhibited UVB-induced mTOR activation, upregulated LC3-II, Atg5, Beclin 1, and reduced p62 in both UVB induced HDF cells and BALB/c mice, while blocking of autophagy successfully halt the GM effects against the UVB-induced increase of cell senescence, degradation of collagen through upregulation of MMP-1, underscoring GM's substantial anti-skin aging impact via autophagy induction in vitro and in vivo.

CONCLUSION

Together, GM has potent antioxidant and anti-skin aging ingredients that can be used to formulate skin care products for both the nutraceutical and cosmeceutical industries.

Role of sRNAs protein molecules in extracellular vesicles derived from Lactobacillus plantarum rejuvenate against ultraviolet B-induced photoaging in human keratinocytes

Ultraviolet B (UVB) radiation accelerates the aging process of skin cells by triggering oxidative stress and inflammatory responses. The aim of this study was to investigate the mechanism of action of sRNAs and protein molecules in the regenerative extracellular vesicles of Lactobacillus plantarum against the UVB-induced photoaging process of human keratinocytes. The extracellular vesicles regenerated by Lactobacillus plantarum were isolated and purified to identify sRNAs and protein components. Human keratinocytes were treated with UVB radiation to simulate the photoaging model. The effects of different concentrations of vesicle extract on cell survival rate, oxidative stress index and inflammatory marker expression were evaluated in control group and treatment group. The results showed that the regenerated extracellular vesicles of L. plantarum significantly improved the survival rate of keratinocytes after UVB radiation, and delayed the aging process of skin cells by reducing oxidative stress and inhibiting inflammatory response.

Emerging production techniques and potential health promoting properties of plant and animal protein-derived bioactive peptides

Bioactive peptides (BPs) are short amino acid sequences that that are known to exhibit physiological characteristics such as antioxidant, antimicrobial, antihypertensive and antidiabetic properties, suggesting that they could be exploited as functional foods in the nutraceutical industry. These BPs can be derived from a variety of food sources, including milk, meat, marine, and plant proteins. In the past decade, various methods including in silico, in vitro, and in vivo techniques have been explored to unravel underlying mechanisms of BPs. To forecast interactions between peptides and their targets, in silico methods such as BIOPEP, molecular docking and Quantitative Structure-Activity Relationship modeling have been employed. Additionally, in vitro research has examined how BPs affect enzyme activities, protein expressions, and cell cultures. In vivo studies on the contrary have appraised the impact of BPs on animal models and human subjects. Hence, in the light of recent literature, this review examines the multifaceted aspects of BPs production from milk, meat, marine, and plant proteins and their potential bioactivities. We envisage that the various concepts discussed will contribute to a better understanding of the food derived BP production, which could pave a way for their potential applications in the nutraceutical industry.

Pilose Antler Protein Relieves UVB-Induced HaCaT Cells and Skin Damage

Extended exposure to UVB (280-315 nm) radiation results in oxidative damage and inflammation of the skin. Previous research has demonstrated that pilose antler extracts have strong anti-inflammatory properties and possess antioxidant effects. This study aimed to elucidate the mechanism of pilose antler protein in repairing photodamage caused by UVB radiation in HaCaT cells and ICR mice. Pilose antler protein (PAP) was found to increase the expression of type I collagen and hyaluronic acid in HaCaT cells under UVB irradiation while also inhibiting reactive oxygen species (ROS) production and oxidative stress in vitro. In vivo, the topical application of pilose antler protein effectively attenuated UVB-induced skin damage in ICR mice by reducing interleukin-1β (IL-β), interleukin-6 (IL-6), and tumor necrosis factor-α (TNF-α) and inhibiting skin inflammation while alleviating UVB-induced oxidative stress. It was shown that pilose antler protein repaired UVB-induced photodamage through the MAPK and TGF-β/Smad pathways.

3D Models Currently Proposed to Investigate Human Skin Aging and Explore Preventive and Reparative Approaches: A Descriptive Review

Skin aging is influenced by intrinsic and extrinsic factors that progressively impair skin functionality over time. Investigating the skin aging process requires thorough research using innovative technologies. This review explores the use of in vitro human 3D culture models, serving as valuable alternatives to animal ones, in skin aging research. The aim is to highlight the benefits and necessity of improving the methodology in analyzing the molecular mechanisms underlying human skin aging. Traditional 2D models, including monolayers of keratinocytes, fibroblasts, or melanocytes, even if providing cost-effective and straightforward methods to study critical processes such as extracellular matrix degradation, pigmentation, and the effects of secretome on skin cells, fail to replicate the complex tissue architecture with its intricated interactions. Advanced 3D models (organoid cultures, "skin-on-chip" technologies, reconstructed human skin, and 3D bioprinting) considerably enhance the physiological relevance, enabling a more accurate representation of skin aging and its peculiar features. By reporting the advantages and limitations of 3D models, this review highlights the importance of using advanced in vitro systems to develop practical anti-aging preventive and reparative approaches and improve human translational research in this field. Further exploration of these technologies will provide new opportunities for previously unexplored knowledge on skin aging.

Investigating the inhibitory effects of carotenoids-fortified Helix aspersa slime on oxidative stress, collagenase and tyrosinase enzyme activities

BACKGROUND

The investigations of snail slime and its possible biological activities have been performed recently.

AIM

This study aimed to evaluate the properties of Helix aspersa snail slime (HAS), and carotenoids-fortified slime (HASC).

METHODS

Snails were fed with carrots for 10 days. Slime was collected and extracted using water. Saponins identification, antioxidant, collagenase, and tyrosinase enzyme inhibition activities, carotenoids, total phenols, and flavonoids content, were determined. UHPLC-MS/MS analysis was performed for phytochemical characterization.

RESULTS

Saponins were detected in the HAS extract only. However, HASC was shown to contain a higher carotenoid content than HAS (29.51 ± 0.4 vs. 18.11 ± 0.2 μg/g). similarly, total phenolic and flavonoid content were higher for the the HASC extract compared to the HAS (182.3 ± 5.2 vs. 150.28 ± 3.3 mg/g equivalent to gallic acid), and (77.62 ± 1.2 vs. 14.19 ± 0.9 mg/g equivalent to quercetin). As expected, the HASC extract exhibited higher antioxidant activity compared to the HAS, using DPPH and the ABTS assays (IC50 = 7.75 ± 0.14 vs. 20.1 ± 0.4 μg/mL), and (IC50 = 7.6 ± 0.26 vs. 19.57 ± 1.4 μg/mL). UHPLC-MS/MS analysis revealed the presence of several phytocomponents of which, hexadecanoic acid and ascorbic acid, were observed in the HASC extract. Furthermore, HASC extract exhibited superior inhibitory activity compared to HAS against collagenase and tyrosinase enzymes (IC50 = 8.4 ± 1.19 vs. 15.3 ± 1.12 μg/mL) and (IC50 = 30.1 ± 0.91 vs. 35 ± 1.3 μg/mL).

CONCLUSION

These findings highlight the potential of HASC as a valuable ingredient in various pharmaceutical applications, due to their content of various phenolic, antioxidants, carotenoids, hexadecanoic, and ascorbic acids. The latter is well known for its great cosmeceutical applications used for slowing the process of skin aging.

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

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

Dermal Injection of Recombinant Filaggrin-2 Ameliorates UVB-Induced Epidermal Barrier Dysfunction and Photoaging

The epidermal barrier is vital for protecting the skin from environmental stressors and ultraviolet (UV) radiation. Filaggrin-2 (FLG2), a critical protein in the stratum corneum, plays a significant role in maintaining skin barrier homeostasis. However, the precise role of FLG2 in mitigating the adverse effects of UV-induced barrier disruption and photoaging remains poorly understood. In this study, we revealed that UVB exposure resulted in a decreased expression of FLG2 in HaCaT keratinocytes, which correlated with a compromised barrier function. The administration of recombinant filaggrin-2 (rFLG2) enhanced keratinocyte differentiation, bolstered barrier integrity, and offered protection against apoptosis and oxidative stress induced by UVB irradiation. Furthermore, in a UV-induced photodamage murine model, the dermal injection of rFLG2 facilitated the enhanced restoration of the epidermal barrier, decreased oxidative stress and inflammation, and mitigated the collagen degradation that is typical of photoaging. Collectively, our findings suggested that targeting FLG2 could be a strategic approach to prevent and treat skin barrier dysfunction and combat the aging effects associated with photoaging. rFLG2 emerges as a potentially viable therapy for maintaining skin health and preventing skin aging processes amplified by photodamage.

Elevating Skincare Science: Grape Seed Extract Encapsulation for Dermatological Care

The skin is the largest organ in the human body and serves multiple functions such as barrier protection and thermoregulation. The maintenance of its integrity and healthy structure is of paramount importance. Accordingly, technological advances in cosmetic sciences have been directed towards optimizing these factors. Plant-derived ingredients have been explored for their bioactivity profiles and sustainable sources. Grape by-products contain a group of bioactive molecules that display important biological activities. Nonetheless, many of these molecules (e.g., phenolic compounds) are unstable and susceptible to degradation. So, their encapsulation using nano/microsystems (i.e., microdispersions) has been explored as a promising solution. In this work, two grape seed extracts were obtained, one from a single grape variety (GSE-Ov) and another from a mix of five grape varieties (GSE-Sv). These extracts were analysed for their antioxidant and antimicrobial activities, as well as their chemical composition and molecular structure. The extract that showed the most promising properties was GSE-Ov with a DPPH IC50 of 0.079 mg mL-1. This extract was encapsulated in soy lecithin microdispersions coated with pectin, with an encapsulation efficiency of 88.8%. They showed an in vitro release of polyphenols of 59.4% during 24 h. The particles displayed a zeta potential of -20.3 mV and an average diameter of 13.6 µm. Microdispersions proved to be safe under 5 and 2.5 mg mL-1 in HaCaT and HDF cell models, respectively. Additionally, they demonstrated anti-inflammatory activity against IL-1α when tested at 2 mg mL-1. This work enabled the valorisation of a by-product from the wine industry by using natural extracts in skincare products.

Progranulin: A promising biomarker and therapeutic target for fibrotic diseases

Progranulin (PGRN), a multifunctional growth factor-like protein expressed by a variety of cell types, serves an important function in the physiologic and pathologic processes of fibrotic diseases, including wound healing and the inflammatory response. PGRN was discovered to inhibit pro-inflammation effect by competing with tumor necrosis factor-alpha (TNF-α) binding to TNF receptors. Notably, excessive tissue repair in the development of inflammation causes tissue fibrosis. Previous investigations have indicated the significance of PGRN in regulating inflammatory responses. Recently, multiple studies have shown that PGRN was linked to fibrogenesis, and was considered to monitor the formation of fibrosis in multiple organs, including liver, cardiovascular, lung and skin. This paper is a comprehensive review summarizing our current knowledge of PGRN, from its discovery to the role in fibrosis. This is followed by an in-depth look at the characteristics of PGRN, consisting of its structure, basic function and intracellular signaling. Finally, we will discuss the potential of PGRN in the diagnosis and treatment of fibrosis.

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.

Exploring the interplay between stress mediators and skin microbiota in shaping age-related hallmarks: A review

Psychological stress is a major contributing factor to several health problems (e.g., depression, cardiovascular disease). Around 35 % of the world's population suffers from it, including younger generations. Physiologically, stress manifests through neuroendocrine pathways (Hypothalamic-Pituitary-Adrenal (HPA) axis and Sympathetic-Adrenal-Medullary (SAM) system) which culminate in the production of stress mediators like cortisol, epinephrine and norepinephrine. Stress and its mediators have been associated to body aging, through molecular mechanisms such as telomere attrition, mitochondrial dysfunction, cellular senescence, chronic inflammation, and dysbiosis, among others. Regarding its impact in the skin, stress impacts its structural integrity and physiological function. Despite this review focusing on several hallmarks of aging, emphasis was placed on skin microbiota dysbiosis. In this line, several studies, comprising different age groups, demographic contexts and body sites, have reported skin microbiota alterations associated with aging, and some effects of stress mediators on skin microbiota have also been reviewed in this paper. From a different perspective, since it is not a "traditional" stress mediator, oxytocin, a cortisol antagonist, has been related to glucorticoids inhibition and to display positive effects on cellular aging. This hormone dysregulation has been associated to psychological issues such as depression, whereas its upregulation has been linked to positive social interaction.

Salvianolic acid B protects against UVB-induced skin aging via activation of NRF2

BACKGROUND

Prolonged exposure to sun radiation may result in harmful skin photoaging. Therefore, discovering novel anti-photoaging treatment modalities is critical. An active component isolated from Salvia miltiorrhiza (SM), Salvianolic acid B (Sal-B), is a robust antioxidant and anti-inflammatory agent. This investigation aimed to discover the therapeutic impact and pathways of salvianolic acid B for UVB-induced skin photoaging, an area that remains unexplored.

METHODS

We conducted in vitro experiments on human dermal fibroblasts (HDFs) exposed to UVB radiation, assessing cellular senescence, superoxide dismutase (SOD) activity, cell viability, proliferation, migration, levels of reactive oxygen species (ROS), and mitochondrial health. The potential mechanism of Sal-B was analyzed using RNA sequencing, with further validation through Western blotting, PCR, and nuclear factor erythroid 2-related factor 2 (NRF2) silencing methods. In vivo, a model of skin photoaging induced by UVB in nude mice was employed. The collagen fiber levels were assessed utilizing hematoxylin and eosin (H&E), Masson, and Sirus red staining. Additionally, NRF2 and related gene and protein expression levels were identified utilizing PCR and Western blotting.

RESULTS

Sal-B was found to significantly counteract photoaging in UVB-exposed skin fibroblasts, reducing aging-related decline in fibroblast proliferation and an increase in apoptosis. It was observed that Sal-B aids in protecting mitochondria from excessive ROS production by promoting NRF2 nuclear translocation. NRF2 knockdown experiments established its necessity for Sal-B's anti-photoaging effects. The in vivo studies also verified Sal-B's anti-photoaging efficacy, surpassing that of tretinoin (Retino-A). These outcomes offer novel insights into the contribution of Sal-B in developing clinical treatment modalities for UVB-induced photodamage in skin fibroblasts.

CONCLUSION

In this investigation, we identified the Sal-B protective impact on the senescence of dermal fibroblasts and skin photoaging induced by radiation of UVB. The outcomes suggest Sal-B as a potential modulator of the NRF2 signaling pathway.

Age-related changes in the bacterial composition of healthy female facial skin in Beijing area

OBJECTIVE

Exploring the effects of age on microbial community structure and understanding the effects of chronological ageing as well as sun exposure on microbial community diversity.

METHOD

The microbial characteristics of the facial skin of 98 adult women aged 18-70 years were studied using 16S rRNA gene sequencing, and differences based on age and reported sun exposure were assessed.

RESULTS

The cheek skin's bacterial diversity and richness increased with age. The relative abundance of Cutibacterium decreased with age, while the relative abundance of Corynebacterium, Anaerococcus, Paracoccus, Micrococcus, Kocuria, Kytococcus, and Chryseobacterium increased. In addition, an increase in Micrococcus and a decrease in Cutibacterium were observed in volunteers with more than 2 h of daily sun exposure compared to volunteers with <2 h of daily sun exposure. Under low-sunlight conditions, Cutibacterium was more prevalent in the youth group, and Corynebacterium, Anaerococcus, and Kytococcus were more prevalent in the older group.

CONCLUSION

The diversity and composition of the bacterial community on the cheeks are affected by age and extrinsic factors (sun exposure) may also play a role in this.

Instant and Multifunctional Nanofibers Loaded with Proanthocyanidins and Hyaluronic Acid for Skincare Applications

Hyaluronic-acid- and silk-fibroin-based nanofibrous mats loaded with proanthocyanidins and collagen peptides were fabricated as multifunctional facial masks using electrospinning. Their morphology, hygroscopicity and moisture retention, DPPH, ABTS free radical scavenging abilities, and cytocompatibility were investigated. The results showed that the nanofibrous mats were dense and uniform, with an average diameter ranging from 300 to 370 nm. The nanofibrous mats exhibited satisfactory moisture retention, oxidation resistance, biocompatibility, especially excellent DPPH, and ABTS free radical scavenging capacities. DPPH free radical scavenging activity was 90% with 15 mg/L nanofibers, and ABTS free radical scavenging activity was 90% with 0.005 mg/L nanofibers. The nanofibrous mats protected fibroblasts from oxidative stress damage induced by tert-butyl hydroperoxide (t-BHP) and significantly promoted their proliferation. Compared with traditional liquid masks and semi-solid facial masks, the multifunctional nanofibrous mats prepared in this study contained fewer additives, which has significant advantages in terms of safety. The nanofibrous mats were rapidly dissolved within 5 s after being sprayed with water, which facilitated the release and penetration of active ingredients for skincare. Therefore, the multifunctional nanofibrous mats displayed excellent moisture retention, oxidation resistance, and biocompatibility, indicating promising translational potential as facial masks and providing a valuable reference for skincare.

Adverse outcome pathway-based approach to reveal the mechanisms of skin sensitization and long-term aging effects of chlorothalonil

Chlorothalonil (CHT) is a widely used antifungal agent and is reported to be a sensitizer that can cause allergic contact dermatitis (ACD). ACD initiation is associated with various innate immune cell contributions and is usually accompanied by persistent inflammation, which is a potential contributing factor to skin damage. However, detailed information on the mechanisms by which CHT induces skin sensitization and damage is still insufficient. This study focused on investigating the possible sensitization process and mechanism of CHT and the adverse effects of repeated CHT exposure. CHT activates dendritic cells and promotes the proliferation of lymph cells in the skin sensitization phase, causing severe inflammation. Keratinocytes activate the NLRP3 inflammasome pathway to cause inflammation during CHT treatment, and macrophages also secrete inflammatory cytokines. In addition, CHT-induced inflammation triggered skin wrinkles, decreased epidermal thickness and decreased collagen. Cell experiments also showed that repeated exposure to CHT led to cell proliferation inhibition and senescence, and CHT-induced autophagy dysfunction was not only the reason for inflammation but also for senescence. This study defined the possible process through which CHT is involved in the skin sensitization phase and elucidated the mechanism of CHT-induced inflammation in innate immune responses. We also determined that repeated CHT exposure caused persistent inflammation, ultimately leading to skin aging.

Kunzea Ericoides (Kanuka) Leaf Extracts Show Moisturisation, Antioxidant, and UV Protection Effects in HaCaT Cells and Anti-melanogenesis Effects in B16F10 Cells

Kunzea ericoides (kanuka) products are well-known for their potent medicinal values in antioxidant and anti-inflammatory applications. The present study identified various compounds, such as chlorogenic acid, gallic acid, quercetin, and (E)-ferulic acid in the kanuka leaf extract, showing its potential use in maintaining skin health. The influence of kanuka leaf extract upon epidermal cells concerning cytotoxicity and in vitro activities of moisturisation, antioxidation, UV protection, and anti-melanogenesis effects were explored in the study. Kanuka leaf extract demonstrated significant promotion in the proliferation of HaCaT and B16F10 cells. After incubation with kanuka leaf extract, the content of ROS and DPPH in HaCaT was significantly decreased; at the same time, more SOD was produced. Furthermore, hyaluronidase-1 (HYAL-1) and HYAL-4 expressions were inhibited, while the aquaporin 3 (AQP-3) content was significantly increased in HaCaT. Kanuka leaf extract also inhibited the expressions of matrix metalloproteinases-1 (MMP-1) and MMP-14 in UV-induced HaCaT cells. In the B16F10 cell line, melanin and tyrosinase production were decreased under the presence of kanuka leaf extract, and the expressions of microphthalmia-associated transcription factor (MITF), tyrosinase-related protein-1 (TYRP-1), and TYRP-2 were also inhibited. The study validated kanuka leaf extract as an effective natural product against photoaging and melanogenesis.

Antiaging, Brightening, and Antioxidant Efficacy of Fermented Bilberry Extract (Vaccinium myrtillus): A Randomized, Double-Blind, Placebo-Controlled Trial

Strategies for successful aging, including the use of food supplements, are part of the approach to support skin youthfulness. To demonstrate the efficacy of fermented bilberry extract (FBE) against skin aging and uneven complexion, a clinical trial was carried out on 66 subjects with visible "crow's feet" wrinkles, mild-to-moderate skin slackness, and uneven skin tone. The wrinkle depth, skin smoothness (Ra) and roughness (Rz), skin firmness (R0) and elasticity (R2), skin coloration (ITA°), and skin antioxidant capacity were measured before and after 28 (D28), 56 (D56), and 84 (D84) days of product use (either FBE or a placebo). These parameters were also integrated with a clinical evaluation, carried out by a dermatologist, and a self-assessment questionnaire to align the measured efficacy with the visual or perceived efficacy. At D84, the wrinkle depth had decreased by 10.6%, Ra had improved by 7.9%, Rz had decreased by 7.3%, R0 had improved by 13.3%, R2 had improved by 12.4%, and skin antioxidant capacity had increased by 20.8%. ITA° increased by 20.8% and was accompanied by a decrease in the skin's redness component by 16.8% and an increase in the lightness component by 2.2%. The variation of all the above-mentioned parameters was statistically significant between the FBE and PL groups. Our findings demonstrate the efficacy of FBE in improving skin aging and complexion evenness.

The Role of PGC-1α in Aging Skin Barrier Function

Skin provides a physical and immune barrier to protect the body from foreign substances, microbial invasion, and desiccation. Aging reduces the barrier function of skin and its rate of repair. Aged skin exhibits decreased mitochondrial function and prolonged low-level inflammation that can be seen in other organs with aging. Peroxisome proliferator-activated receptor (PPAR)-γ coactivator-1α (PGC-1α), an important transcriptional coactivator, plays a central role in modulating mitochondrial function and antioxidant production. Mitochondrial function and inflammation have been linked to epidermal function, but the mechanisms are unclear. The aim of this review is to discuss the mechanisms by which PGC-1α might exert a positive effect on aged skin barrier function. Initially, we provide an overview of the function of skin under physiological and aging conditions, focusing on the epidermis. We then discuss mitochondrial function, oxidative stress, cellular senescence, and inflamm-aging, the chronic low-level inflammation observed in aging individuals. Finally, we discuss the effects of PGC-1α on mitochondrial function, as well as the regulation and role of PGC-1α in the aging epidermis.

Anti-aging activity of Syn-Ake peptide by in silico approaches and in vitro tests

The increase in the aging population worldwide has led scientists to turn to research to prevent the aging process. In this context, synthetic peptides emerge as candidate molecules for developing new anti-aging products. This study aims to investigate the possible interactions of Syn-Ake, a synthetic peptide, with matrix metalloproteinases (MMPs) and Sirtuin 1 (SIRT1), which are the targets of anti-aging activities with in silico approaches, and to determine the antioxidant activity, and safety profile of the peptide by in vitro methods such as cytotoxicity (MTT) and genotoxicity (Ames) tests. The molecular docking study showed that the docking score energy of MMP receptors was in the order of MMP-13 < MMP-8 < MMP-1. Syn-Ake peptide provided the lowest and the most stable binding to the SIRT1 receptor at -9.32 kcal/mol. Binding interaction and protein-ligand stability of Syn-Ake with MMPs and SIRT1 in a dynamic system were predicted by 50 ns molecular dynamic (MD) simulation studies. The MD results showed that the Syn-Ake peptide remained stable in the active site of MMP-13 and SIRT1 receptors during 50 ns simulations. In addition, the antioxidant activity of Syn-Ake was investigated using diphenyl-2-picril-hydrazine (DPPH) method since it is crucial to remove free radicals that are effective in skin aging. The results revealed the concentration-dependent increased DPPH radical scavenging activity of the peptide. Finally, the safety of the Syn-Ake was investigated, and the safe dose of the peptide was determined. In conclusion, in silico and in vitro analyses show that the Syn-Ake peptide may hold promise in anti-aging formulations with its high efficacy and safety profile.Communicated by Ramaswamy H. Sarma.

Exploring the anti-skin inflammation substances and mechanism of Paeonia lactiflora Pall. Flower via network pharmacology-HPLC integration

BACKGROUND

Paeonia lactiflora Pall. (PL) is widely used in China as a homologous plant of medicine and food. PL flower is rich in bioactive substances with anti-inflammatory effects, while the pathogenesis of skin inflammation is complex and the specific mechanism is not clear, the current treatment of skin inflammation is mainly hormonal drugs, and hormonal drugs have obvious toxic side effects. The research on the treatment of skin inflammation by PL flowers is relatively small, so this study provides a basis for the development and utilisation of PL resources.

OBJECTIVE

Our study was to investigate the interventional effects of PL flower extracts on skin inflammation and thus to understand its functional role in the treatment of skin inflammation and its molecular mechanisms.

METHODS

The major active substances in PL flower extracts were investigated by the HPLC-DAD method, and the potential targets of action were predicted by network pharmacology, which was combined with in vitro experimental validation to explore the mechanism of PL flower extracts on the regulation of skin inflammation. The HPLC-DAD analysis identified seven major active components in PL flower extracts, and in response to the results, combined with the potential mechanism of network pharmacological prediction with skin inflammation, the PL flower extract is closely related to MAPK and NF-κB signaling pathways. In addition, we also investigated the interventional effects of PL flower extract on skin inflammation by western blot detection of MAPK signaling pathway and NF-κB signaling pathway proteins in cells.

RESULT

Seven active components were identified and quantified from the extract of PL flowers, including Gallic acid, 1,2,3,4,6-O-Pentagalloylglucose, Oxypaeoniflorin, Paeoniflorin, Albiflorin, Benzoyloxypeoniflorin, and Rutin. It was predicted targets for the treatment of skin inflammation, with PPI showing associations with targets such as TNF, MAPK1, and IL-2. KEGG enrichment analysis revealed that the main signaling pathways involved included MAPK and T cell receptor signaling pathways. Cell experiments showed that the peony flower extract could inhibit the release of NO and inflammatory factors, as well as reduce ROS levels and inhibit cell apoptosis. Furthermore, the extract was found to inhibit the activation of the MAPK and NF-κB signaling pathways in cells.

CONCLUSIONS

In this study, we found that PL flower extract can inhibit the production of cell inflammatory substances, suppress the release of inflammatory factors, and deactivate inflammatory signaling pathways, further inhibiting the production of cell inflammation. This indicates that PL flower extract has a therapeutic effect on skin inflammation.

Unveiling the potential of Pseudococcomyxa simplex: a stepwise extraction for cosmetic applications

Microalgae are gaining attention as they are considered green fabrics able to synthesize many bioactive metabolites, with unique biological activities. However, their use at an industrial scale is still a challenge because of the high costs related to upstream and downstream processes. Here, a biorefinery approach was proposed, starting from the biomass of the green microalga Pseudococcomyxa simplex for the extraction of two classes of molecules with a potential use in the cosmetic industry. Carotenoids were extracted first by an ultrasound-assisted extraction, and then, from the residual biomass, lipids were obtained by a conventional extraction. The chemical characterization of the ethanol extract indicated lutein, a biosynthetic derivative of α-carotene, as the most abundant carotenoid. The extract was found to be fully biocompatible on a cell-based model, active as antioxidant and with an in vitro anti-aging property. In particular, the lutein-enriched fraction was able to activate Nrf2 pathway, which plays a key role also in aging process. Finally, lipids were isolated from the residual biomass and the isolated fatty acids fraction was composed by palmitic and stearic acids. These molecules, fully biocompatible, can find application as emulsifiers and softener agents in cosmetic formulations. Thus, an untapped microalgal species can represent a sustainable source for cosmeceutical formulations. KEY POINTS: • Pseudococcomyxa simplex has been explored in a cascade approach. • Lutein is the main extracted carotenoid and has antioxidant and anti-aging activity. • Fatty acids are mainly composed of palmitic and stearic acids.

Prediction, screening and characterization of novel bioactive tetrapeptide matrikines for skin rejuvenation

BACKGROUND

Extracellular matrices play a critical role in tissue structure and function and aberrant remodelling of these matrices is a hallmark of many age-related diseases. In skin, loss of dermal collagens and disorganization of elastic fibre components are key features of photoageing. Although the application of some small matrix-derived peptides to aged skin has been shown to beneficially affect in vitro cell behaviour and, in vivo, molecular architecture and clinical appearance, the discovery of new peptides has lacked a guiding hypothesis.

OBJECTIVES

To identify, using protease cleavage site prediction, novel putative matrikines with beneficial activities for skin composition and structure.

METHODS

Here, we present an in silico (peptide cleavage prediction) to in vitro (proteomic and transcriptomic activity testing in cultured human dermal fibroblasts) to in vivo (short-term patch test and longer-term split-face clinical study) discovery pipeline, which enables the identification and characterization of peptides with differential activities.

RESULTS

Using this pipeline we showed that cultured fibroblasts were responsive to all applied peptides, but their associated bioactivity was sequence-dependent. Based on bioactivity, toxicity and protein source, we further characterized a combination of two novel peptides, GPKG (glycine-proline-lysine-glycine) and LSVD (leucine-serine-valine-aspartate), that acted in vitro to enhance the transcription of matrix -organization and cell proliferation genes and in vivo (in a short-term patch test) to promote processes associated with epithelial and dermal maintenance and remodelling. Prolonged use of a formulation containing these peptides in a split-face clinical study led to significantly improved measures of crow's feet and firmness in a mixed population.

CONCLUSIONS

This approach to peptide discovery and testing can identify new synthetic matrikines, providing insights into biological mechanisms of tissue homeostasis and repair and new pathways to clinical intervention.

Insights into the role of mesenchymal stem cells in cutaneous medical aesthetics: from basics to clinics

With the development of the economy and the increasing prevalence of skin problems, cutaneous medical aesthetics are gaining more and more attention. Skin disorders like poor wound healing, aging, and pigmentation have an impact not only on appearance but also on patients with physical and psychological issues, and even impose a significant financial burden on families and society. However, due to the complexities of its occurrence, present treatment options cannot produce optimal outcomes, indicating a dire need for new and effective treatments. Mesenchymal stem cells (MSCs) and their secretomics treatment is a new regenerative medicine therapy that promotes and regulates endogenous stem cell populations and/or replenishes cell pools to achieve tissue homeostasis and regeneration. It has demonstrated remarkable advantages in several skin-related in vivo and in vitro investigations, aiding in the improvement of skin conditions and the promotion of skin aesthetics. As a result, this review gives a complete description of recent scientific breakthroughs in MSCs for skin aesthetics and the limitations of their clinical applications, aiming to provide new ideas for future research and clinical transformation.

Exogenous Nucleotides Improve the Skin Aging of SAMP8 Mice by Modulating Autophagy through MAPKs and AMPK Pathways

The skin, serving as the body's primary defense against external elements, plays a crucial role in protecting the body from infections and injuries, as well as maintaining overall homeostasis. Skin aging, a common manifestation of the aging process, involves the gradual deterioration of its normal structure and repair mechanisms. Addressing the issue of skin aging is increasingly imperative. Multiple pieces of evidence indicate the potential anti-aging effects of exogenous nucleotides (NTs) through their ability to inhibit oxidative stress and inflammation. This study aims to investigate whether exogenous NTs can slow down skin aging and elucidate the underlying mechanisms. To achieve this objective, senescence-accelerated mouse prone-8 (SAMP8) mice were utilized and randomly allocated into Aging, NTs-low, NTs-middle, and NTs-high groups, while senescence-accelerated mouse resistant 1 (SAMR1) mice were employed as the control group. After 9 months of NT intervention, dorsal skin samples were collected to analyze the pathology and assess the presence and expression of substances related to the aging process. The findings indicated that a high-dose NT treatment led to a significant increase in the thickness of the epithelium and dermal layers, as well as Hyp content (p < 0.05). Additionally, it was observed that low-dose NT intervention resulted in improved aging, as evidenced by a significant decrease in p16 expression (p < 0.05). Importantly, the administration of high doses of NTs could improve, in some ways, mitochondrial function, which is known to reduce oxidative stress and promote ATP and NAD+ production significantly. These observed effects may be linked to NT-induced autophagy, as evidenced by the decreased expression of p62 and increased expression of LC3BI/II in the intervention groups. Furthermore, NTs were found to upregulate pAMPK and PGC-1α expression while inhibiting the phosphorylation of p38MAPK, JNK, and ERK, suggesting that autophagy may be regulated through the AMPK and MAPK pathways. Therefore, the potential induction of autophagy by NTs may offer benefits in addressing skin aging through the activation of the AMPK pathway and the inhibition of the MAPK pathway.

Exploring the Impact of French Raw-Milk Cheeses on Oxidative Process Using Caenorhabditis elegans and Human Leukocyte Models

Fermented foods, including cheeses, have garnered increased interest in recent years for their potential health benefits. This study explores the biological properties of eight French raw-milk cheeses-goat cheese, Saint-Nectaire, Cantal, Bleu d'Auvergne, Roquefort, Comté, Brie de Meaux, and Epoisses-on oxidative processes using both in vivo (Caenorhabditis elegans) and in vitro (human leukocytes) models. A cheese fractionation protocol was adapted to study four fractions for each cheese: a freeze-dried fraction (FDC) corresponding to whole cheese, an apolar (ApE), and two polar extracts (W40 and W70). We showed that all cheese fractions significantly improved Caenorhabditis elegans (C. elegans) survival rates when exposed to oxidative conditions by up to five times compared to the control, regardless of the fractionation protocol and the cheese type. They were also all able to reduce the in vivo accumulation of reactive oxygen species (ROS) by up to 70% under oxidative conditions, thereby safeguarding C. elegans from oxidative damage. These beneficial effects were explained by a reduction in ROS production up to 50% in vitro in human leukocytes and overexpression of antioxidant factor-encoding genes (daf-16, skn-1, ctl-2, and sod-3) in C. elegans.

Ergothioneine Protects Against UV-Induced Oxidative Stress Through the PI3K/AKT/Nrf2 Signaling Pathway

Background

Ergothioneine (EGT) is an antioxidant, which could be detected in human tissues, and human skin cells could utilize EGT and play an anti-oxidative role in keratinocytes. And in this study we are going to elucidate whether EGT could protect the skin from photoaging by Ultraviolet (UV) exposure in mice and its molecule pathway.

Methods

Histological analysis was performed for evaluating the skin structure change. Malondialdehyde (MDA) and superoxide dismutase (SOD) levels were measured with biological assay for evaluating oxidative and antioxidative ability of skin exposed to UV light. And the level of marker molecules in mouse skin were detected by hydroxyproline (Hyp) assay, immunohistochemical analysis, Western blot, and quantitative real-time PCR (qRT-PCR). The markers of skin aging and cell death were tested by cell culture and treatment, Western blot and qRT-PCR.

Results

EGT decreased the levels of inflammatory factors induced by UV exposure in mouse skin. MDA and SOD activity detection showed that EGT decreased MDA levels, increased SOD activity, and upregulated PI3K/Akt/Nrf2 signals in mouse skin exposed to UV, which further activated Nrf2 in the nucleus and enhanced the expression of Nrf2 target genes. In the cell model, we revealed that EGT could inhibit the increase in senescence-associated β-galactosidase-positive cells and p16 and γ-H2A.X positive cells induced by etoposide and activate PI3K/Akt/Nrf2 signaling. Moreover, a PI3K inhibitor blocked EGT protection against etoposide-induced cell death.

Conclusion

The study showed EGT may play an important protective role against cell damage or death through the PI3K/Akt/Nrf2 signaling pathway in skin.

Aging of Superficial Musculoaponeurotic System of the Face-Novel Biomarkers and Micro-CT Relevance of Facial Anti-Gravity Support

The soft superficial tissues of the face are against gravity through an intricate network of ligaments and ligamentous attachments. The aim of this investigation is to delineate the relationship between the muscular, fibrous, and vascular components of the superficial musculoaponeurotic system of the face (SMAS) at the level of its periosteal fixation areas from advanced radiological and novel biomarkers' perspectives. These areas represent key points underlying skin aging and the longevity of restorative surgery results. Methods: This study was carried out on 37 surgical specimens, excised from patients admitted for surgery. On the excised specimens, we used special immunohistochemical techniques, such as markers for collagen type III, angiogenesis, vascular endothelium (I-CAM2) and muscle fibers (MYH2). We performed a micro-CT evaluation of these 37 specimens. Results: The results of this study showed different radiologic and IHC characteristics of the means of periosteal fixation of the SMAS. Evidence of morphohistological and radiological peculiarities of the retaining ligaments highlights new data for future functional studies of these structures. Our research must be continued with larger groups of subjects and through detailed methodological studies of vascular microperfusion and could represent an important new step in biotissue engineering and the customization of surgical techniques involving the sub-SMAS layers.

Specific Knockdown of the NDUFS4 Gene Reveals Important Roles of Ferroptosis in UVB-induced Photoaging

Ultraviolet (UV) irradiation significantly contributes to photoaging. Ferroptosis, an iron-dependent cell death mode recently identified, plays a key role in UVB-induced skin photoaging. This study examines the functions and regulatory mechanisms of ferroptosis in this regard. Characterized by increased intracellular iron and reactive oxygen species (ROS), ferroptosis is associated with mitochondrial function and structure. Through RNA sequencing, we identified NADH: ubiquinone oxidoreductase subunit S4 (NDUFS4), a gene implicated in UVB-mediated photoaging, and explored its role in ferroptosis by NDUFS4 knockdown. In vitro, inhibiting NDUFS4 reduced ferroptosis, decreased ROS and matrix metallopeptidase 1 levels, and increased collagen type I alpha 1 chain, glutathione peroxidase 4 (GPX4), ferritin heavy chain 1, and solute carrier family 7 member 11 levels, suggesting a reinforced ferroptosis protective mechanism. Additionally, NDUFS4 regulates ferroptosis via the mitogen-activated protein kinase (MAPK) pathway, with its knockdown reducing p38 and ERK phosphorylation and elevating GPX4 levels, enhancing ferroptosis resistance. Animal experiments supported these findings, demonstrating that Ferrostatin-1, a ferroptosis inhibitor, significantly mitigated UVB-induced skin photoaging and related protein expression. This study uncovers NDUFS4's novel role in regulating ferroptosis and provides new insights into ferroptosis-mediated UVB-induced skin photoaging.

Oral Administration of Deer Bone Collagen Peptide Can Enhance the Skin Hydration Ability and Antioxidant Ability of Aging Mice Induced by D-Gal, and Regulate the Synthesis and Degradation of Collagen

Skin problems caused by aging have attracted much attention, and marine collagen peptides have been proved to improve these problems, while mammalian collagen peptides are rarely reported. In this study, fermented deer bone collagen peptide (FCP) and non-fermented deer bone collagen peptide (NCP) were extracted from fermented and non-fermented deer bone, respectively, and their peptide sequences and differential proteins were analyzed using LC-MS/MS technology. After they were applied to aging mice induced with D-gal, the skin hydration ability, antioxidant ability, collagen synthesis, and degradation ability of the mice were studied. The results show that FCP and NCP are mainly peptides that constitute type Ⅰ collagen, and their peptide segments are different. In vivo experiments show that FCP and NCP can improve the richness of collagen fibers in the skin of aging mice; improve the hydration ability of skin; promote the activity of antioxidant-related enzymes; and also show that through the TGF-β and MAPK pathways, the synthesis and degradation of collagen in skin are regulated. These results show that deer bone collagen peptide can improve skin problems caused by aging, promote skin hydration and antioxidant capacity of aging mice, and regulate collagen synthesis and degradation through the MAPK pathway.

Immunoglobulin Superfamily Containing Leucine-Rich Repeat (ISLR) Serves as a Redox Sensor That Modulates Antioxidant Capacity by Suppressing Pyruvate Kinase Isozyme M2 Activity

Cells defend against oxidative stress by enhancing antioxidant capacity, including stress-activated metabolic alterations, but the underlying intracellular signaling mechanisms remain unclear. This paper reports that immunoglobulin superfamily containing leucine-rich repeat (ISLR) functions as a redox sensor that responds to reactive oxygen species (ROS) stimulation and modulates the antioxidant capacity by suppressing pyruvate kinase isozyme M2 (PKM2) activity. Following oxidative stress, ISLR perceives ROS stimulation through its cysteine residue 19, and rapidly degrades in the autophagy-lysosome pathway. The downregulated ISLR enhances the antioxidant capacity by promoting the tetramerization of PKM2, and then enhancing the pyruvate kinase activity, PKM2-mediated glycolysis is crucial to the ISLR-mediated antioxidant capacity. In addition, our results demonstrated that, in triple-negative breast cancer, cisplatin treatment reduced the level of ISLR, and PKM2 inhibition sensitizes tumors to cisplatin by enhancing ROS production; and argued that PKM2 inhibition can synergize with cisplatin to limit tumor growth. Our results demonstrate a molecular mechanism by which cells respond to oxidative stress and modulate the redox balance.

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.

Effects of castration and eucalyptus oil supplementation on growth performance, nutrient digestibility, and blood-immunity indicators of male Holstein calves

The purpose of this study was to investigate the effects of early castration and eucalyptus oil (EUC) supplementation on dry matter intake (DMI), growth performance, and immune response of Holstein calves. Fifty-six male Holstein calves 52 d old and with an initial body weight (BW) of 63.5 ± 5.27 kg were used. The animals were blocked by BW and randomly assigned into 1 of the 4 treatment groups in a randomized complete block design with a 2 (no castration vs. castration) × 2 (without vs. with EUC) factorial arrangement of treatments. The treatments were (1) uncastrated calves fed without EUC, (2) uncastrated calves fed 0.5 g/d EUC (EUC group), (3) castrated calves (steers) fed without EUC (castrated group), and (4) steers fed with 0.5 g/d EUC (castrated + EUC). The experiment was 8 wk long, including pre- and postweaning (weaned at 72 d). The EUC × castrated interactions were not significant for DMI, growth performance, nutrient digestibility, and immune response. Castration did not affect the DMI, final BW, average daily gain (ADG), or feed efficiency, except that the ADG was greater for bull calves than for steers at postweaning. Supplementation with EUC increased DMI pre- and postweaning and increased the ADG of weaned calves. Digestibility in the total digestive tract was not affected by castration (except for organic matter digestibility), whereas adding EUC improved the digestibility of dry matter, acid detergent fiber, and crude protein. Blood concentration of IL-6 at d 94 was decreased by feeding EUC. These results indicate that the EUC could be fed to either intact or castrated dairy calves to promote growth and health postweaning; castration before weaning may reduce ADG and cause inflammatory stress without affecting feed intake or feed efficiency.

Downregulated SPESP1-driven fibroblast senescence decreases wound healing in aged mice

BACKGROUND

Human dermal fibroblasts (HDFs) are essential in the processes of skin ageing and wound healing. However, the underlying mechanism of HDFs in skin healing of the elderly has not been well defined. This study aims to elucidate the mechanisms of HDFs senescence and how senescent HDFs affect wound healing in aged skin.

METHODS

The expression and function of sperm equatorial segment protein 1 (SPESP1) in skin ageing were evaluated via in vivo and in vitro experiments. To delve into the potential molecular mechanisms by which SPESP1 influences skin ageing, a combination of techniques was employed, including proteomics, RNA sequencing, immunoprecipitation, chromatin immunoprecipitation and liquid chromatography-mass spectrometry analyses. Clearance of senescent cells by dasatinib plus quercetin (D+Q) was investigated to explore the role of SPESP1-induced senescent HDFs in wound healing.

RESULTS

Here, we define the critical role of SPESP1 in ameliorating HDFs senescence and retarding the skin ageing process. Mechanistic studies demonstrate that SPESP1 directly binds to methyl-binding protein, leading to Decorin demethylation and subsequently upregulation of its expression. Moreover, SPESP1 knockdown delays wound healing in young mice and SPESP1 overexpression induces wound healing in old mice. Notably, pharmacogenetic clearance of senescent cells by D+Q improved wound healing in SPESP1 knockdown skin.

CONCLUSIONS

Taken together, these findings reveal the critical role of SPESP1 in skin ageing and wound healing, expecting to facilitate the development of anti-ageing strategies and improve wound healing in the elderly.

Comparison of five retinoids for anti-photoaging therapy: Evaluation of anti-inflammatory and anti-oxidative activities in vitro and therapeutic efficacy in vivo

Over the past decades, increasing evidences have demonstrated that five retinoids, including retinol (ROL), retinol acetate (RAc), retinol propionate (RP), retinol palmitate (RPalm), and hydroxypinacolone retinoate (HPR), can be potential therapeutic agents for skin photoaging. However, therapeutic efficacies and biosafety have never been compared to these compounds. This study aimed to determine the optimal retinoid type(s) for anti-photoaging therapy both in vitro and in vivo. Our data demonstrated that four retinoids (RPalm, RP, HPR and ROL) but not RAc were effective for anti-photoaging treatment at 5 μg/mL in vitro, with action mechanisms associated with antioxidative, anti-inflammatory and anti-skin ECM degradation activities. Notably, both RPalm and RP appeared superior to HPR and ROL for those activities. Importantly, both RPalm and RP were shown to be optimal for anti-photoaging therapy when topically applied at 5 mg/kg in a UVB-induced mice model of photoaging, which is consistent with their high anti-photoaging activities in vitro. Additionally, topical application of these five retinoids showed satisfactory biosafety without causing significant apoptosis in animal organs, although RP application led to a slight decline in animal body weights. Collectively, these data have laid a good foundation for the next development of the clinical application of these retinoids for skin healthcare.

Water-soluble intracellular extract of Desmodesmus sp. YT enhanced the antioxidant capacity of human skin fibroblast to protect the skin from UV damage

BACKGROUND

The oxidative stress induced by ultraviolet (UV) radiation is a pivotal factor in skin aging and can even contribute to the development of skin cancer.

AIM

This study explored the antioxidant effect and mechanism of water-soluble intracellular extract (WIE) of Desmodesmus sp.YT (YT), aiming to develop a natural antioxidant suitable for incorporation into cosmetics.

METHODS

The study evaluated the scavenging capacity of YT-WIE against free radicals and assessed its impact on human skin fibroblasts (HSF) cell viability and UV resistance using Cell Counting Kit-8 (CCK-8). Transcriptome sequencing was employed to elucidate the mechanism of action, while RT-qPCR and western blot were used to validate the expression of key genes.

RESULTS

YT-WIE displayed robust antioxidant activity, demonstrating potent scavenging abilities against 2,2-diphenyl-1-picrylhydrazyl (DPPH; IC50 = 0.55 mg mL-1), 2,2'-Azino-bis (3 ethylbenzothiazoline-6-sulfonic acid; ABTS; IC50 = 3.11 mg mL-1), Hydroxyl (·OH; IC50 = 2.21 mg mL-1), and Superoxide anion (O2 •-; IC50 = 0.98 mg mL-1). Furthermore, compared to the control group, the YT-WIE group exhibited an 89.30% enhancement in HSF viability and a 44.63% increase in survival rate post-UV irradiation. Significant upregulation of antioxidant genes (GCLC, GCLM, TXNRD1, HMOX1, NQO1) was observed with YT-WIE treatment at 400 μg mL-1, with fold increases ranging from 1.13 to 5.85 times.

CONCLUSION

YT-WIE demonstrated considerable potential as an antioxidant, shielding human cells from undue oxidative stress triggered by external stimuli such as UV radiation. This suggests its promising application in cosmetics antioxidants.

Isolation, purification, and biological activities of polysaccharides from Amorpha fruticosa flowers

The extraction, isolation, structural characterisation and biological activities of polysaccharides from Amorpha fruticosa flowers were investigated. First, the crude polysaccharide AFP was extracted, and two major purified polysaccharide fractions AFP-2 and AFP-3 were isolated. The molecular weight and monosaccharide compositions of AFP-2 and AFP-3 were determined. Then the antioxidant activities of AFP, AFP-2 and AFP-3 were assessed by DPPH radical, β-Carotene bleaching and hydroxyl radical assays. All three tested polysaccharides showed good antioxidant activity while AFP was the strongest one. The study also showed that AFP, AFP-2 and AFP-3 have good tyrosinase inhibition, moisture absorption and retention activities. The results will provide a helpful reference for the application of polysaccharide from Amorpha fruticosa flowers as a natural cosmetic ingredient.

Ferulic acid in synergy with retinol alleviates oxidative injury of HaCaT cells during UVB-induced photoaging

Application of retinol (Vitamin A, VA) in skincare is limited for instability, poor water solubility, and skin intolerance that combats skin aging. We employed computer-aided virtual screening and cell experiments with transcriptomics, thereby unveiling the comprehensive gene expression and regulation pathway of photoaging HaCaT cell treated with ferulic acid (FA) in synergizing with VA. Through network pharmacology analysis, the combined use of VA and FA exhibited highly correlated cross-targets with skin aging acting on EGFR, PTPN1, ESR2, GSK3B, BACE1, PYGL, PTGS2 and APP. The indicators of oxidative stress, such as SOD, GSH, MDA, CAT and ROS in HaCaT cells after co-administration, were significantly improved from those in photoaging group (p<0.0001). 155 differential expressed genes (DEGs) were specific between groups, while reducing the expression of PTGS2 was identified as an important regulatory factor in photoaging HaCaT cells by VA and FA. Those DEGs of co-administration group focused on oxidative-reduction enzyme activity, skin growth, keratinization, and steroid biosynthesis. Apparently, the co-administration of VA and FA effectively mitigated the process of UVB-induced photoaging by reducing oxidative stress injury, inflammation responses, and regulating cell growth. This synergistic approach significantly slowed down the photoaging progression and improved the applied performance of VA in HaCaT cells.

BPA induces hepatotoxicity in zebrafish through oxidative stress and apoptosis pathways

BPA is so ubiquitous that 27 million tons of BPA-containing plastic, including mineral water bottles and baby bottles, is produced worldwide each year. The potential toxicity of BPA to humans and aquatic organisms has been the subject of intense research. In this study, a zebrafish model system was used to assess BPA-mediated hepatotoxicity. Zebrafish larvae at 72-144 hpf were exposed to BPA at different concentrations (0,1, 3 and 5mg/L). For example, BPA-treated zebrafish larvae showed increased mortality, delayed uptake of nutrients in yolk sac, shortened body length, smaller liver area, abnormal expression of genes related to liver development, and pathological changes in the liver tissue. Mechanistically, BPA exposure induced excessive oxidative stress in the liver of zebrafish and increased the level of hepatocyte apoptosis in zebrafish larvae, and the antioxidant astaxanthin could rescue the BPA-mediated liver toxicity.