Changes in human skin composition due to intrinsic aging: a histologic and morphometric study.

Skin represents the main barrier against the external environment, but also plays a role in human relations, as one of the prime determinants of beauty, resulting in a high consumer demand for skincare-related pharmaceutical products. Given the importance of skin aging in both medical and social spheres, the present research aims to characterize microscopic changes in human skin composition due to intrinsic aging (as opposed to aging influenced by external factors) via histological analysis of a photoprotected body region. Samples from 25 autopsies were taken from the periumbilical area and classified into four age groups: group 1 (0-12 years), group 2 (13-25 years), group 3 (26-54 years), and group 4 (≥ 55 years). Different traditional histological (hematoxylin-eosin, Masson's trichrome, orcein, toluidine, Alcian blue, and Feulgen reaction) and immunohistochemical (CK20, CD1a, Ki67, and CD31) stains were performed. A total of 1879 images photographed with a Leica DM3000 optical microscope were morphometrically analyzed using Image ProPlus 7.0 for further statistical analysis with GraphPad 9.0. Our results showed a reduction in epidermis thickness, interdigitation and mitotic indexes, while melanocyte count was raised. Papillary but not reticular dermis showed increased thickness with aging. Specifically, in the papillary layer mast cells and glycosaminoglycans were expanded, whereas the reticular dermis displayed a diminution in glycosaminoglycans and elastic fibers. Moreover, total cellularity and vascularization of both dermises were diminished with aging. This morphometric analysis of photoprotected areas reveals that intrinsic aging significantly influences human skin composition. This study paves the way for further research into the molecular basis underpinning these alterations, and into potential antiaging strategies.

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-ß-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-ß-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.

Improvement in Facial Wrinkles Using Materials Enhancing PPARGC1B Expression Related to Mitochondrial Function.

Skin aging is an unavoidable natural phenomenon caused by intrinsic and extrinsic factors. In modern society, the pursuit of a wrinkle-free and aesthetically appealing face has gained considerable prominence. Numerous studies have aimed at mitigating the appearance of facial wrinkles. Antiaging research focused on regulating the function of mitochondria, the main reactive oxygen species-generating organelles, has been extensively conducted. In this study, we investigated the correlation between facial wrinkles and the expression of PPARGC1B, considering the association of this gene with mitochondrial function, to identify its potential as a target for exploring antiaging cosmetic materials. We elucidated the role of PPARGC1B in the skin and identified five bioactive materials that modulated its expression. The effectiveness of these materials was verified through in vitro experiments on human dermal fibroblasts. We prepared cosmetic formulations incorporating the five materials and confirmed their ability to enhance dermal collagen in three-dimensional skin models and reduce facial wrinkles under the eyes and nasolabial fold areas in human subjects. The study findings have significant implications for developing novel antiaging cosmetic formulations by reinforcing mitochondrial functions.

Three-Dimensional Bioprinted Skin Microrelief and Its Role in Skin Aging.

Skin aging is a complex physiological process, in which cells and the extracellular matrix (ECM) interreact, which leads to a change in the mechanical properties of skin, which in turn affects the cell secretion and ECM deposition. The natural skin microrelief that exists from birth has rarely been taken into account when evaluating skin aging, apart from the common knowledge that microreliefs might serve as the starting point or initialize micro-wrinkles. In fact, microrelief itself also changes with aging. Does the microrelief have other, better uses? In this paper, owing to the fast-developing 3D printing technology, skin wrinkles with microrelief of different age groups were successfully manufactured using the Digital light processing (DLP) technology. The mechanical properties of skin samples with and without microrelief were tested. It was found that microrelief has a big impact on the elastic modulus of skin samples. In order to explore the role of microrelief in skin aging, the wrinkle formation was numerically analyzed. The microrelief models of different age groups were created using the modified Voronoi algorithm for the first time, which offers fast and flexible mesh formation. We found that skin microrelief plays an important role in regulating the modulus of the epidermis, which is the dominant factor in wrinkle formation. The wrinkle length and depth were also analyzed numerically for the first time, owing to the additional dimension offered by microrelief. The results showed that wrinkles are mainly caused by the modulus change of the epidermis in the aging process, and compared with the dermis, the hypodermis is irrelevant to wrinkling. Hereby, we developed a hypothesis that microrelief makes the skin adaptive to the mechanical property changes from aging by adjusting its shape and size. The native-like skin samples with microrelief might shed a light on the mechanism of wrinkling and also help with understanding the complex physiological processes associated with human skin.

Myofunctional Speech Therapy for Facial Rejuvenation and Orofacial Function Improvement: A Systematic Review.

This review aims to reveal the effectiveness of myofunctional speech therapy on facial rejuvenation and/or improvement of orofacial function. A systematic review of four medical electronic databases (Medline, Google Scholar, SciELO, and LILACS) was conducted between January and March 2023. The research question was defined using the PICO model: Population (P): adult subjects with signs of physiological aging of facial skin. Intervention (I): aesthetic speech therapy (facial exercises and/or myofunctional therapy). Control (C): absence of treatment. Outcome (O): facial rejuvenation. Through the search process, a total of 472 potentially relevant articles were identified. A total of 21 studies were included in the review. Most of the studies required the participants to perform exercises learned during the weekly session on a daily basis. The subjects underwent an integrated treatment with facial exercises and worked on the stomatognathic functions for different durations. Many differences were found in the evaluation tools used to investigate the starting situation and the effects obtained following the treatment. At the diagnostic level, there was no concordance in the choice of the most appropriate scales and assessment tools, but great heterogeneity was observed. Indeed, forty-eight percent of the studies collected objective data through the use of various instruments (oral devices, electromyographs, cutometers, muscle ultrasound scans, and laser scans of the face). The observed improvements included not only a reduction in wrinkles and frown lines but also decreased muscle tension and slackness, enhanced facial symmetry and lip competence, improved skin elasticity, and restored stomatognathic function. These changes led to myofunctional restoration and facial rejuvenation, resulting in increased satisfaction with self-image and proprioception.

Is diet related to skin condition? A Mendelian randomization study.

Observational studies have revealed associations between various dietary factors and skin conditions. However, the causal relationship between diet and skin condition is still unknown. Data on 17 dietary factors were obtained from the UK Biobank. Data on four skin conditions were derived from the UK Biobank and another large-scale GWAS study. Genetic predictions suggested that the intake of oily fish was associated with a lower risk of skin aging (OR: 0.962, P = 0.036) and skin pigmentation (OR: 0.973, P = 0.033); Tea intake was associated with a lower risk of skin pigmentation (OR: 0.972, P = 0.024); Salad/raw vegetables intake was associated with a lower risk of keratinocyte skin cancer (OR: 0.952, P = 0.007). Coffee intake was associated with increased risk of skin aging (OR: 1.040, P = 0.028); Pork intake was associated with increased risk of skin aging (OR: 1.134, P = 0.020); Beef intake was associated with increased risk of cutaneous melanoma (OR: 1.013, P = 0.016); Champagne plus white wine intake was associated with increased risk of cutaneous melanoma (OR: 1.033, P = 0.004); Bread intake was associated with increased risk of keratinocyte skin cancer (OR: 1.026, P = 0.013). Our study results indicate causal relationships between genetically predicted intake of oily fish, tea, salad/raw vegetables, coffee, pork, beef, champagne plus white wine, and bread and skin conditions.

Matrikines in the skin: Origin, effects, and therapeutic potential.

The extracellular matrix (ECM) represents a complex multi-component environment that has a decisive influence on the biomechanical properties of tissues and organs. Depending on the tissue, ECM components are subject to a homeostasis of synthesis and degradation, a subtle interplay that is influenced by external factors and the intrinsic aging process and is often disturbed in pathologies. Upon proteolytic cleavage of ECM proteins, small bioactive peptides termed matrikines can be formed. These bioactive peptides play a crucial role in cell signaling and contribute to the dynamic regulation of both physiological and pathological processes such as tissue remodeling and repair as well as inflammatory responses. In the skin, matrikines exert an influence for instance on cell adhesion, migration, and proliferation as well as vasodilation, angiogenesis and protein expression. Due to their manifold functions, matrikines represent promising leads for developing new therapeutic options for the treatment of skin diseases. This review article gives a comprehensive overview on matrikines in the skin, including their origin in the dermal ECM, their biological effects and therapeutic potential for the treatment of skin pathologies such as melanoma, chronic wounds and inflammatory skin diseases or for their use in anti-aging cosmeceuticals.

The silent UVA.

The effects of UVA on the skin are well documented in the literature. Sunscreens were originally developed to protect against erythema and consequently against UVB. Even today, most sunscreens on the market provide much higher UVB than UVA protection. By looking at the transmission profile of 3 different sunscreens on the market and making a theoretical calculation, we show that users in the past and even today are being exposed to a huge amount of UVA in a silent way. This is what we define as silent UVA. There is a need to develop a new generation of sunscreens with higher UVA protection to reduce Silent UVA exposure.

Poly-l-lactic acid microspheres delay aging of epidermal stem cells in rat skin.

Objective: Injectable skin fillers offer a wider range of options for cutaneous anti-aging and facial rejuvenation. PLLA microspheres are increasingly favored as degradable and long-lasting fillers. The present study focused solely on the effect of PLLA on dermal collagen, without investigating its impact on the epidermis. In this study, we investigated the effects of PLLA microspheres on epidermal stem cells (EpiSCs). Methods: Different concentrations of PLLA microspheres on epidermal stem cells (EpiSCs) in vitro through culture, and identification of primary rat EpiSCs. CCK-8 detection, apoptosis staining, flow cytometry, Transwell assay, wound healing assay, q-PCR analysis, and immunofluorescence staining were used to detect the effects of PLLA on EpiSCs. Furthermore, we observed the effect on the epidermis by injecting PLLA into the dermis of the rat skin in vivo. Results: PLLA microspheres promote cell proliferation and migration while delaying cell senescence and maintaining its stemness. In vitro, Intradermal injection of PLLA microspheres in the rat back skin resulted in delayed aging, as evidenced by histological and immunohistochemical staining of the skin at 2, 4, and 12 weeks of follow-up. Conclusion: This study showed the positive effects of PLLA on rat epidermis and EpiSCs, while providing novel insights into the anti-aging mechanism of PLLA.

Study on the anti-skin aging effect and mechanism of Sijunzi Tang based on network pharmacology and experimental validation.

ETHNOPHARMACOLOGICAL RELEVANCE: Si Jun Zi Tang (SJZT) is a famous traditional Chinese medicine formula composing of 4 herbal medicines (Ginseng Radix et Rhizoma, Atractylodis macrocephalae Rhizoma, Poria, and Glycyrrhizae Radix et Rhizoma) with tonifying spleen and anti-aging effects. It is also known that SJZT can be used to tone, nourish the skin and accelerate wound healing. However, due to the complexity of the formulation, the anti-aging especially anti-skin aging mechanisms as well as the key components of SJZT have not been fully investigated. Therefore, further in vitro and in vivo experimental studies are particularly needed to investigate the anti-skin ageing efficacy of SJZT. AIM OF THE STUDY: The purpose of this article was to explore the therapeutic effect and possible pharmacological mechanism of SJZT in the treatment of skin aging by topical application using network pharmacology and to validate the findings using in vitro and in vivo tests. MATERIALS AND METHODS: Network pharmacology method was applied to predict the underlying biological function and mechanism involved in the anti-skin aging effect of SJZT. Molecular docking was used to preliminarily predict the active components of SJZT-Skin Aging. UPLC QTOF MS/MS was carried out to analyze the chemical compounds. Finally, to confirm the anti-skin aging effort of SJZT, a mouse skin-aging model and UVB-induced EpiSCs (epidermal stem cells) senescence model were established. RESULTS: PPI network analysis and KEGG studies indicated that TP53, CDKN2A, TNF, IL6, and IL1B might be parts of the core targets associated with EpiSCs senescence. Furthermore, molecular docking suggested the top active components, glycyrrhizin, ginsenoside Rg5, ginsenoside Rh2, liquiritin, polyporenic acid C and atractylenolide II showed strong affinity to the key proteins involved in cellular senescence signaling. UPLC QTOF MS/MS analysis of SJZT confirmed the presence of these key components. In-vivo experiments revealed that SJZT could improve UVB-induced skin thickening, increase the number of collagen fibers, strengthen the structure of elastin fibers, and decrease the expression of MDA, as well as increase the expression of CAT and T-SOD in the skin tissue of mouse. And, in-vitro experiments indicated that SJZT could reduce ROS generation and oxidative stress, increase mitochondrial membrane potential, and upregulate the expression of stem cell markers. Moreover, SJZT could suppress the expression of p53, p-p53 and p21, downregulated p38 phosphorylation. Furthermore, the anti-cellular senescence effect of SJZT on EpiSCs disappeared after treatment with the p38 inhibitor adesmapimod. Taken all together, the regulation of senescence signaling in EpiSCs is an important mechanism of SJZT in combating skin aging. CONCLUSION: The research results indicate that SJZT has anti-skin aging effects on UVB-induced skin-aging model, possibly by mediating p38/p53 signaling pathway. These findings strongly demonstrate the great potential of SJZT as an active composite for anti-skin aging and cosmeceutical applications.

Liquid collagen from freshwater fish skin ameliorates hydration, roughness and elasticity in photo-aged skin: a randomized, controlled, clinical study.

BACKGROUND/OBJECTIVES: Collagen is commonly used in diverse forms as a functional component in skincare products. On the other hand, the effects of collagen on human skin are controversial. Dietary collagen hydrolysates from freshwater Pangasius hypophthalmus fish skin ameliorated photo-aged skin of hairless mice. This study conducted a randomized, double-blind, placebo-controlled clinical trial to determine if liquid fish collagen (Collagen-Tripep20™, Tripep20) as a drink strengthens skin health and quality. SUBJECTS/METHODS: In this clinical trial, 85 subjects aged 35-60 yrs were diagnosed with photo-aged skin. Eighty-five subjects were randomized to receive either Tripep20 (n = 44) or placebo (n = 41). Seventy-eight subjects fully participating for a 12-week period consumed 1,000 mg of Tripep20 (n = 41) or placebo (n = 37) in a 50-mL bottle as a daily drink. The intend-to-treat and per-protocol populations were 85 and 78, respectively. Skin hydration, wrinkles, and elasticity were assessed at 0 (baseline), 6, and 12 weeks during the study period. RESULTS: Skin hydration in the Tripep20 group was significantly higher from 6 weeks (P < 0.001) than the baseline. After 12 weeks, the Crow's-feet visual score and skin roughness (Ra, Rq, and Rmax) were significantly improved in the Tripep20 group than in the placebo group (P < 0.05). Consuming liquid collagen Tripep20 greatly enhanced skin elasticity (Gross R2, Net R5, and Biological elasticity R7) in 6 weeks compared to the placebo group. The Tripep20 group showed a significant increase in skin elasticity from the baseline after 6 and 12 weeks (P < 0.001). Neither abnormal symptoms nor adverse events were encountered during the study period in subjects ingesting Tripep20 or placebo. The changes in parameters related to hematology and clinical chemistry were within the normal ranges. CONCLUSION: Oral consumption of liquid collagen Tripep20 was safe and well-tolerated. The results of this study show that freshwater fish-derived liquid collagen Tripep20 can be used as a healthy functional food ingredient to improve skin moisturizing, anti-wrinkling, and elasticity in an aging population.

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 ß-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.

Photothermal Biostimulation of Platelet-Rich Plasma Improves Hand Rejuvenation Clinical Outcome: A Pilot Study.

Objective: This study aimed to evaluate physical skin changes and patients' subjective perception of treatment with photothermal bioactivated platelet-rich plasma (MCT Plasma) for hand rejuvenation. Background: Age-related changes in the dorsum of the hand include volume loss, dyschromia, and soft-tissue atrophy, which result in wrinkles and prominent deep structures. Methods: We conducted a prospective, single-center, randomized pilot study on 10 healthy female volunteers from 30 to 65 years with hand aging signs. Patients received two sessions of MCT Plasma on the treated hand and two sessions of standard platelet-rich plasma (PRP) on the control hand. Results were assessed through high-frequency ultrasonography, photographs, a patient satisfaction survey, patient perception of skin aspect, and patient perception of amelioration survey. Results: Ten women with a mean age of 57.5 years (standard deviation 10.5, range 31 - 67) were included, and seven (70%) completed the study. The treated hands' skin subepidermal low-echogenic band (SLEB) decreased from 20% to 60%, and 57.1% (n = 4) had better results than control. Twenty percent of patients were very satisfied with the results, 40% were satisfied, 40% were neutral, and none were unsatisfied or very unsatisfied. Patients perceived the skin of the treated hand (MCT Plasma) as "much better" (20%), "better" (60%), and "no changes" (20%) compared with the skin of the control hand (standard PRP). No treatment-related adverse events were reported during the study. Conclusions: Hands treated with MCT Plasma tended to have better outcomes in reducing SLEB compared with those treated with standard PRP. Patients were satisfied and the treatment was safe with no technical complications. However, further randomized controlled trials with larger sample sizes are mandatory to validate the extent of improvement provided by this device based on photothermal biomodulation.

The efficacy of hyaluronic acid fragments with amino acid in combating facial skin aging: an ultrasound and histological study.

BACKGROUND: Various techniques have been employed in aesthetic medicine to combat skin aging, in particular that of the facial region. Hyaluronic acid is utilized to enhance moisture levels and extracellular matrix molecules. This study aims to histologically assess the effects of low molecular weight hyaluronic acid fragments combined with amino acids (HAAM) on facial skin rejuvenation through intradermal microinjections. METHODS: A total of twenty women, with an average age of 45 and ranging from 35 to 64 years old, participated in the study, including 8 in menopause and 12 in the childbearing age group. Mesotherapy was used to administer HAAM to the patients. Prior to and three months after the treatment, each patient underwent small circular punch biopsies. Ultrasound examinations were conducted using B-mode, capturing 2D images in longitudinal or transverse orientations with frequencies ranging from 5 to 13 Mega-hertz (MY LAB X8, ESAOTE, Genova, Italy). A total of 60 ultrasound examinations were taken, with 30 collected before treatment and 30 after treatment. RESULTS: The histological analysis demonstrates an increase in fibroblast activity resulting in the production of Type III reticular collagen, as well as an increased number of blood vessels and epidermal thickness. However, the analysis of ultrasound data before and after treatment showed no statistical difference in skin thickness in malar area, chin and mandibular angle. CONCLUSIONS: Histological assessments indicate that subcutaneous infiltration of HAAM has a substantial impact on the dermis of facial skin.

Adipose-Derived Mesenchymal Stem Cells and Their Derived Epidermal Progenitor Cells Conditioned Media Ameliorate Skin Aging in Rats.

BACKGROUND: Skin alterations are among the most prominent signs of aging, and they arise from both intrinsic and extrinsic factors that interact and mutually influence one another. The use of D-galactose as an aging model in animals has been widely employed in anti-aging research. Adipose tissue-derived mesenchymal stem cells (Ad-MSCs) are particularly promising for skin anti-aging therapy due to their capacity for effective re-epithelization and secretion of various growth factors essential for skin regeneration. Accordingly, we aimed to examine the potential utility of Ad-MSCs as a therapy for skin anti-aging. METHODS: In this study, we isolated and characterized adipose-derived mesenchymal stem cells (Ad-MSCs) from the epididymal fat of male Sprague Dawley rats. We assessed the in vitro differentiation of Ad-MSCs into epidermal progenitor cells (EPCs) using ascorbic acid and hydrocoritsone. Additionally, we induced skin aging in female Sprague Dawley rats via daily intradermal injection of D-galactose over a period of 8 weeks. Then we evaluated the therapeutic potential of intradermal transplantation of Ad-MSCs and conditioned media (CM) derived from differentiated EPCs in the D-galactose-induced aging rats. Morphological assessments, antioxidant assays, and histopathological examinations were performed to investigate the effects of the treatments. RESULTS: Our findings revealed the significant capability of Ad-MSCs to differentiate into EPCs. Notably, compared to the group that received CM treatment, the Ad-MSCs-treated group exhibited a marked improvement in morphological appearance, antioxidant levels and histological features. CONCLUSIONS: These results underscore the effectiveness of Ad-MSCs in restoring skin aging as a potential therapy for skin 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.

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-ß-gal staining, collagen, MDA content, si-RNA experiments, and promoter assays. Western blotting evaluated protein levels of c-Jun, c-Fos, p-IκBα/ß, 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 ß-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.

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.

Oral Administration of Nacre Extract from Pearl Oyster Shells Has Anti-Aging Effects on Skin and Muscle, and Extends the Lifespan in SAMP8 Mice.

Pearl oysters have been extensively utilized in pearl production; however, most pearl oyster shells are discarded as industrial waste. In a previous study, we demonstrated that the intraperitoneal administration of pearl oyster shell-derived nacre extract (NE) prevented d-galactose-induced brain and skin aging. In this study, we examined the anti-aging effects of orally administered NE in senescence-accelerated mice (SAMP8). Feeding SAMP8 mice NE prevented the development of aging-related characteristics, such as coarse and dull hair, which are commonly observed in aged mice. Additionally, the NE mitigated muscle aging in SAMP8 mice, such as a decline in grip strength. Histological analysis of skeletal muscle revealed that the NE suppressed the expression of aging markers, cyclin-dependent kinase inhibitor 2A (p16) and cyclin-dependent kinase inhibitor 1 (p21), and increased the expression of sirtuin1 and peroxisome proliferator-activated receptor gamma coactivator 1 (PGC1)- α, which are involved in muscle synthesis. These findings suggest that the oral administration of NE suppresses skeletal muscle aging. Moreover, NE administration suppressed skin aging, including a decline in water content. Interestingly, oral administration of NE significantly extended the lifespan of SAMP8 mice, suggesting that its effectiveness as an anti-aging agent of various tissues including skeletal muscle, skin, and adipose tissue.

Evaluating the Impact of Oleocanthal and Oleacein on Skin Aging: Results of a Randomized Clinical Study.

The prevalence of skin aging and the request for effective treatments have driven dermatological research towards natural solutions. This study investigates the anti-aging efficacy of two bioactive natural polyphenols, Oleocanthal and Oleacein, in a skincare formulation. A single-blind, randomized clinical trial involved 70 participants, using a comprehensive exclusion criterion to ensure participant safety and study integrity. Participants applied the Oleocanthal and Oleacein 1% serum formulation twice daily for 30 days. The efficacy was objectively assessed using the VISIA® Skin Analysis System at baseline, after 15 days, and after 30 days. Results indicated significant wrinkle reduction in most groups. For women aged 45-79 years, the mean change was -33.91% (95% CI: -46.75% to -21.07%). For men aged 20-44 years, it was -51.93% (95% CI: -76.54% to -27.33%), and for men aged 45-79 years, it was -46.56% (95% CI: -58.32% to -34.81%). For women aged 20-44 years, the change was -25.68% (95% CI: -63.91% to 12.54%), not statistically significant. These findings highlight the potential of EVOO-derived polyphenols in anti-aging skincare, particularly for older adults. This research paves the way for further exploration into natural compounds in dermatology, particularly for aging skin management.