Estrogen-deficient skin: The role of topical therapy

Endocrine Controls of Skin Aging

Skin is the largest organ of the human body and undergoes both intrinsic (chronological) and extrinsic aging. While intrinsic skin aging is driven by genetic and epigenetic factors, extrinsic aging is mediated by external threats such as UV irradiation or fine particular matters, the sum of which is referred to as exposome. The clinical manifestations and biochemical changes are different between intrinsic and extrinsic skin aging, albeit overlapping features exist, eg, increased generation of reactive oxygen species, extracellular matrix degradation, telomere shortening, increased lipid peroxidation, or DNA damage. As skin is a prominent target for many hormones, the molecular and biochemical processes underlying intrinsic and extrinsic skin aging are under tight control of classical neuroendocrine axes. However, skin is also an endocrine organ itself, including the hair follicle, a fully functional neuroendocrine "miniorgan." Here we review pivotal hormones controlling human skin aging focusing on IGF-1, a key fibroblast-derived orchestrator of skin aging, of GH, estrogens, retinoids, and melatonin. The emerging roles of additional endocrine players, ie, α-melanocyte-stimulating hormone, a central player of the hypothalamic-pituitary-adrenal axis; members of the hypothalamic-pituitary-thyroid axis; oxytocin, endocannabinoids, and peroxisome proliferator-activated receptor modulators, are also reviewed. Until now, only a limited number of these hormones, mainly topical retinoids and estrogens, have found their way into clinical practice as anti-skin aging compounds. Further research into the biological properties of endocrine players or its derivatives may offer the development of novel senotherapeutics for the treatment and prevention of skin aging.

Bioactives for Estrogen-Deficient Skin: Topical and Oral Supplement Clinical Studies. A Narrative Review

Bioactive compound applications by topical or oral administration have gained increased utilization/awareness in providing health benefits particularly due to changes in hormone levels and aging, especially in women with the decline and loss of estrogens. This narrative review focuses on the bioactive compounds such as the phytoestrogens that have estrogenic properties for improving skin health. Notably, phytoestrogens bind and/or activate estrogen beta receptors, which are abundant in skin layers to improve dermal health. This review presents: (a) skin characteristics with aging in women, (b) changes in hormone levels with aging in women (especially with estrogen deficiency), (c) the characteristics of phytoestrogens and other bioactive compounds, (d) topical and oral clinical studies of bioactive compounds (phytoestrogens) as antiaging treatment(s) for estrogen-deficient skin (during peri- and postmenopause), and (e) the advantages of treating the skin from the outside to inside by traditional topical therapies and treating the skin from the inside to the outside by nutraceutical supplementation, which represents a relatively new innovation of increasing popularity. While this is a growing area of research with promising results, more investigations are needed to understand the mechanism(s) of how combination ingredient formulations work to improve skin health and slow down the advancement of the aging process.

Results of a patient survey exploring skin symptoms in a menopause clinic

BackgroundThe menopause leads to a reduction in circulating estrogen and progesterone levels, which trigger physiological changes in women. This includes cutaneous changes where these hormonal receptors are present and potential deterioration of previously diagnosed dermatoses. We suspect that the prevalence of skin, hair, vulval and oral symptoms experienced during the menopausal time may be underestimated and may not be considered associated with the menopause in presenting patients.MethodsA survey was conducted to investigate the dermatological symptoms experienced by women attending a menopause clinic. The Dermatology Life Quality Index (DLQI) was also recorded for each patient.ResultsA high prevalence of skin, hair, vulval and oral symptoms was reported by participants, and these symptoms appear to have an impact on quality of life.ConclusionThese findings highlight the need for research into the management of these symptoms, including the role of hormone replacement therapy amongst other treatment modalities.

Efficacy and safety of combined topical estradiol with minoxidil vs. topical minoxidil in female pattern hair loss: a trichoscopic randomized controlled trial

BACKGROUND

Female pattern hair loss (FPHL) is common and has a negative impact on quality of life. FPHL is more challenging to treat than male pattern hair loss, with minoxidil being the gold standard treatment. Several studies have used 17α-estradiol solution for treating FPHL with variable results, either alone or combined with minoxidil.

OBJECTIVES

To study the safety and efficacy of topical 17α-ethinylestradiol 0.01% combined with minoxidil 2% in comparison with minoxidil 2% in the treatment of FPHL.

METHODS

Forty-three women with FPHL were recruited to this randomized controlled study and were asked to blindly apply twice daily six puffs of a spray-on solution containing either 17α-ethinylestradiol 0.01% combined with minoxidil 2% (EMX group) or minoxidil 2% alone (MX group). Treatment continued for 6 months. Clinical and trichoscopic assessments were performed at baseline and at the end of the treatment.

RESULTS

At the end of the treatment period, both groups showed signs of improvement. Improvement parameters were better for the EMX group vs. the MX group, but this was not statistically significant. More patients in the EMX group experienced menstrual irregularities. Limitations include the limited number of patients and follow-up period. Also, the effects of estradiol were not studied on a cellular or molecular levels and systemic absorption of both medications was not determined.

CONCLUSIONS

The use of a 0.01% 17α-ethinylestradiol with a 2% minoxidil solution in the treatment of FPHL does not seem to offer a statistically significant advantage compared with minoxidil alone and may carry a higher risk of associated menstrual irregularities.

Phytoestrogens as Natural Anti-Aging Solutions for Enhanced Collagen Synthesis in Skin

BACKGROUND

The dermal extracellular matrix (ECM) is a dynamic scaffold composed mainly of proteins, with collagen as the key structural component providing resilience and support to the skin. Post-menopause, declining estrogen levels lead to a significant reduction in skin health, notably a 30% decrease in collagen types I and III within 5 years.

AIM

To discover natural extracts that stimulate collagen production.

METHODS

We utilized PathwayStudio to analyze protein-protein interactions and identify regulators of essential collagen types. Our study assessed Glycyrrhiza uralensis extract's ability to boost collagen production and enhance dermal density both in vitro and in vivo.

RESULTS

PathwayStudio analysis highlighted phytoestrogens including glycyrrhizin, isoliquiritigenin, liquiritigenin, liquiritin, and glabrol, as potential candidates. Liquorice rhizome (G. uralensis), used in traditional Chinese medicine, is rich in phytoestrogens like liquiritigenin. The G. uralensis extract increased collagen I and III gene expression and pro-collagen I protein levels in human dermal fibroblasts and inhibited UVB and pollution-induced matrix metalloproteinase-1 (MMP1) production. In an in vivo study, a topical formulation containing the extract significantly improved dermal density after 56 days, measured by the DUB SkinScanner.

CONCLUSIONS

These findings suggest G. uralensis extract as a promising agent for enhancing collagen production and skin health, particularly in postmenopausal women. Further research is needed to explore its mechanisms and long-term effects.

Ultra-Performance Liquid Chromatography-Quadrupole-Time-of-Flight-Mass Spectrometry-Based Analysis of Facial Physiological Parameters and Lipid Composition of Between Sensitive Skin of Women Aged 36-42 and 43-49 Year

BACKGROUND

UPLC-Q-TOF-MS (Ultra-Performance Liquid Chromatography-Quadrupole Time-of-Flight Mass Spectrometry) is a high-precision, high-density technology for lipid analysis. Sensitive skin is a sub-stable condition, and it has been reported that the population of sensitive skin in China is predominantly female. Meanwhile, women with sensitive skin have different physiological parameters as well as lipid compositions at different ages. The Yellow Emperor's Classic of Internal Medicine states that the number of women's life cycles is seven, that major changes are manifested every 7 years, and that aging begins at age 35. At present, the correlation between facial lipid composition and aging indicators of sensitive skin in women aged 36-42 and 43-49 years has not been reported.

OBJECTIVE

This study reveals the relationship between key lipid composition of the facial skin and the aging of sensitive skin in women aged 36-42 and 43-49 years.

METHODS

We used UPLC-Q-TOF-MS technology to study the changes in lipid composition in the sensitive skin of woman aged 36-42 and 43-49 years, using a multi-probe adapter system with different types of skin-testing probes to test physiological parameters. Three types of multivariate data-questionnaires, physiological indicators, and lipid composition-were used together to assess differences in aging in a population of women with sensitive skin at different ages.

RESULTS

1. In the questionnaire part, the T1 group was more susceptible to sunburn and the T2 group was more susceptible to tanning. 2. In the physiological index part, the aging characteristics of facial skin in the T2 group were obvious, with the b-value, as well as the brown area size, being significantly higher than the T1 group, while the TWEL, sebum, R2 value, ITA value, pore count, and concentration of the red area were significantly lower than the T1 group. 3. In the lipid part, the total facial lipid content was higher in the T2 group, with a significantly higher GP lipid, and the 47 VIP lipids obtained were analyzed by ROC curves, narrowing down to six lipids, PS(2-OMe-21:0/0:0), PS(O-18:0/20:5 (5Z,8Z,11Z,14Z,17Z)), PA(O-16:0/20:5 (5Z,8Z,11Z,14Z,17Z)), PS (P-16:0/12:0, PA (O-16:0/22:2 (13Z,16Z)), and PC (19:3 (10Z,13Z,16Z)/0:0)), and all six lipids were higher in the T2 group. 4. In Spearman correlation analysis, PS(O-18:0/20:5(5Z,8Z,11Z,14Z,17Z)), PS(P-16:0/12:0), PS(2-OMe-21:0/0:0), PA(O-16:0/20:5(5Z,8Z,11Z,14Z,17Z)), and PC(19:3( 10Z,13Z,16Z)/0:0), which are five lipids and skin aging indicators (TWEL, sebum, ITA value, b-value, pore count, concentration of red area, and brown area size) were significantly correlated.

CONCLUSIONS

Through correlation analysis, it was found that changes in the composition of skin surface lipids (SSLs) in both age groups have an important influence on facial physiological indicators (aging manifestations) and played an important role in furthering the understanding of sensitive skin aging. Therefore, these lipid components also provide theoretical support for the development of cosmetic ingredients that slow down the aging of sensitive skin.

Exploring Black Soybean Extract Cream for Inflammatory Dermatitis-Toward Radiation Dermatitis Relief

We aimed to evaluate the effect of black soybean extract cream (BSEC) on 2,4-dinitrochlorobenzene (DNCB)-induced dermatitis in murine models mimicking inflammatory dermatitis observed in humans. In this DNCB-induced model, BALB/c mice were spread with 100 μL of 2% DNCB twice a week for two weeks to induce skin inflammation on the shaved back skin; then, a placebo or BSEC that consisted of the volatile fraction derived from the seeds of Glycine max (L.) Merr. was applied to the DNCB-sensitized mice for 7 days. Gross visual analysis was conducted to assess the impact of BSEC on dermatitis, and an enzyme-linked immunosorbent assay (ELISA) was subsequently performed to detect inflammatory cytokines in the presence or absence of BSEC after DNCB sensitization. Lastly, the possible mechanisms responsible for the effects of BSEC on inflammatory dermatitis were investigated in a human leukemia monocytic cell line, THP-1. Our study showed that BSEC displayed antioxidant and anti-inflammatory effects. BSEC has the ability to diminish dermatitis, and all three experiments demonstrated that BSEC effectively reduced the progression of dermatitis while significantly suppressing inflammatory responses in the preclinical models. Consequently, BSEC exhibited promising phytotherapy for inflammatory dermatitis, potentially attributed to its anti-inflammatory and antioxidant properties.

The impact of irritant challenge on the skin barrier and myeloid-resident immune cells in women who are postmenopausal is modulated by hormone replacement therapy

BACKGROUND

Sex hormone changes during menopausal transition contribute to declining skin health. However, how menopause and its treatment by hormone replacement therapy (HRT) impact the skin barrier and immune system is unclear.

OBJECTIVES

To examine how menopause and HRT affect the skin barrier and immune cell composition in postmenopausal women following irritant challenge.

METHODS

Two cohorts of postmenopausal women were recruited to the study. The first cohort consisted of 10 untreated women [HRT-; mean (SEM) age 56.5 (1.6) years (range 48-63)] and the second was composed of 8 women receiving HRT [HRT+; mean (SEM) age 54.0 (2.1) years (range 48-63)]. Skin irritation was induced by applying topical sodium lauryl sulfate (SLS) 1.25% to occluded buttock skin for 48 h. Clinical assessment was conducted after 24 h, followed by biopsy of both SLS-challenged and unchallenged skin for analysis of skin barrier proteins and immune cell distribution using immunofluorescence.

RESULTS

Clinically, there were no significant differences in skin irritant responses between those taking or not taking HRT (including increased skin redness and blood flow). In response to SLS challenge a significant increase in transepidermal water loss (P < 0.05), filaggrin deposition and cytokeratin 10 (K10)+ cell layers (P < 0.01) was observed in individuals receiving HRT compared with the HRT- group. Following SLS challenge in individuals taking HRT, a significant (P < 0.01) reduction in CD207+ cells in the epidermis was observed, accompanied by an increase of CD207+ cells in the dermis, indicative of migrating Langerhans cells (LCs). Significantly fewer migrating LCs were found in those who were not receiving HRT (P < 0.01). Furthermore, the numbers of dermal dendritic cells (DCs), macrophages, and CD11c+CD206- and CD68+CD206- subsets were found to be significantly (P < 0.05) higher in those taking HRT following SLS challenge.

CONCLUSIONS

Individuals receiving HRT displayed enhanced skin barrier response to SLS challenge with thicker filaggrin and increased K10+ epidermal cell layers. Following challenge, HRT users exhibited elevated LC, inflammatory DC and macrophage counts in the dermis. These may render skin both more prone to inflammation and more capable of resolving it, while also promoting skin repair.

Estrogen deficiency in the menopause and the role of hormone therapy: integrating the findings of basic science research with clinical trials

ABSTRACT

Menopause, defined by the cessation of menstrual cycles after 12 months of amenorrhea not due to other causes, is associated with significant hormonal changes, primarily a decrease in estrogen, androgen, and progesterone levels. This review delves into the effects of estrogen deficiency during the perimenopausal transition and postmenopause, integrating the findings of basic science with clinical trials. Here, we first outline the variation in endogenous estrogens before and after menopause, exploring both genomic and nongenomic actions of estrogen and its estrogen receptors throughout the body. Next, we detail the spectrum of menopausal symptoms, from acute vasomotor, urogenital, and psychological issues during perimenopause to chronic reproductive, cardiovascular, neurological, skeletal, dermatologic, immune, and digestive changes postmenopause. Finally, we evaluate the role of hormone therapy in alleviating these symptoms, weighing its benefits against known risks. Publicizing these findings and an accurate representation of the risks and benefits of estrogen replacement to our aging patients is fundamental to improving their care, quality, and even quantity of life.

Elastogenesis in Focus: Navigating Elastic Fibers Synthesis for Advanced Dermal Biomaterial Formulation

Elastin, a fibrous extracellular matrix (ECM) protein, is the main component of elastic fibers that are involved in tissues' elasticity and resilience, enabling them to undergo reversible extensibility and to endure repetitive mechanical stress. After wounding, it is challenging to regenerate elastic fibers and biomaterials developed thus far have struggled to induce its biosynthesis. This review provides a comprehensive summary of elastic fibers synthesis at the cellular level and its implications for biomaterial formulation, with a particular focus on dermal substitutes. The review delves into the intricate process of elastogenesis by cells and investigates potential triggers for elastogenesis encompassing elastin-related compounds, ECM components, and other molecules for their potential role in inducing elastin formation. Understanding of the elastogenic processes is essential for developing biomaterials that trigger not only the synthesis of the elastin protein, but also the formation of a functional and branched elastic fiber network.

Integrating bioinformatics and multiple machine learning to identify mitophagy-related targets for the diagnosis and treatment of diabetic foot ulcers: evidence from transcriptome analysis and drug docking

Background

Diabetic foot ulcers are the most common and serious complication of diabetes mellitus, the high morbidity, mortality, and disability of which greatly diminish the quality of life of patients and impose a heavy socioeconomic burden. Thus, it is urgent to identify potential biomarkers and targeted drugs for diabetic foot ulcers.

Methods

In this study, we downloaded datasets related to diabetic foot ulcers from gene expression omnibus. Dysregulation of mitophagy-related genes was identified by differential analysis and weighted gene co-expression network analysis. Multiple machine algorithms were utilized to identify hub mitophagy-related genes, and a novel artificial neural network model for assisting in the diagnosis of diabetic foot ulcers was constructed based on their transcriptome expression patterns. Finally, potential drugs that can target hub mitophagy-related genes were identified using the Enrichr platform and molecular docking methods.

Results

In this study, we identified 702 differentially expressed genes related to diabetic foot ulcers, and enrichment analysis showed that these genes were associated with mitochondria and energy metabolism. Subsequently, we identified hexokinase-2, small ribosomal subunit protein us3, and l-lactate dehydrogenase A chain as hub mitophagy-related genes of diabetic foot ulcers using multiple machine learning algorithms and validated their diagnostic performance in a validation cohort independent of the present study (The areas under roc curve of hexokinase-2, small ribosomal subunit protein us3, and l-lactate dehydrogenase A chain are 0.671, 0.870, and 0.739, respectively). Next, we constructed a novel artificial neural network model for the molecular diagnosis of diabetic foot ulcers, and the diagnostic performance of the training cohort and validation cohort was good, with areas under roc curve of 0.924 and 0.840, respectively. Finally, we identified retinoic acid and estradiol as promising anti-diabetic foot ulcers by targeting hexokinase-2 (-6.6 and -7.2 kcal/mol), small ribosomal subunit protein us3 (-7.5 and -8.3 kcal/mol), and l-lactate dehydrogenase A chain (-7.6 and -8.5 kcal/mol).

Conclusion

The present study identified hexokinase-2, small ribosomal subunit protein us3 and l-lactate dehydrogenase A chain, and emphasized their critical roles in the diagnosis and treatment of diabetic foot ulcers through multiple dimensions, providing promising diagnostic biomarkers and targeted drugs for diabetic foot ulcers.

Treatment of menopausal skin - A narrative review of existing treatments, controversies, and future perspectives

Menopause is a state of estrogen deficiency that affects numerous estrogen-dependent tissues in the female body. Skin is one of the most affected organs. Many consider menopausal skin changes to be merely an aesthetic problem; however, they can significantly affect women's quality of life. Currently, there are no approved effective treatments to prevent or alleviate skin changes associated with estrogen deficiency. Standard systemic hormone replacement therapy used to treat menopausal symptoms may be effective to some degree for skin treatment. In addition, compounded bioidentical hormone replacement therapy, selective estrogen receptor modulators, and phytoestrogens could also be used for skin treatment, although this is only hypothetical due to lack of data. Many questions therefore remain unanswered. On the other hand, topical, low-dose estrogen that would act only on the skin without systemic effects could be a possible option, as could be skin-only acting topical phytoestrogens. Such topical products without systemic effects could play a role in the treatment of menopausal skin. However, they are not currently approved because there is insufficient data on their safety and efficacy. A healthy lifestyle could have a positive effect on the menopausal skin. In this review, we provide an overview of the characteristics of menopausal skin, an outlook on the future treatment of menopausal skin with estrogens and other approaches, and the associated controversies and speculations. Overall, the importance of menopausal skin changes should not be neglected, and high-quality research is needed to gain new insights into the treatment of menopausal skin.

Cosmeceuticals for antiaging: a systematic review of safety and efficacy

Cosmeceuticals, the bridge between pharmaceuticals and cosmetics, contain biologically active ingredients that may improve the skin's overall appearance. As the market, accessibility, and popularity of cosmeceuticals increase, it is essential to understand the safety and efficacy of such products. This systematic review aims to examine published clinical studies involving the use of cosmeceuticals for antiaging to provide evidence-based recommendations based on available efficacy and safety data. PubMed, Embase, and Cochrane were systematically searched on January 1, 2023 using PRISMA guidelines. Strength of evidence was graded using the Oxford Centre for Evidence-Based Medicine guidelines. Clinical recommendations were made based on the quality of the existing literature. A total of 153 articles regarding the use of cosmeceuticals for treatment of antiaging were identified. After screening of titles, abstracts, and full text, 32 studies involving 1236 patients met inclusion criteria, including 20 randomized controlled trials (RCTs) and 12 non-randomized open-label clinical trials for Vitamin C, Retinol, Bakuchiol, Tetrahydrojasmonic acid, Growth Factors, Methyl Estradiolpropanoate, Timosaponin A-III (TA-III), Protocatechuic acid, Grammatophyllum speciosum, and Jasmine rice panicle extract. Retinol and vitamin C for antiaging received a Grade A for recommendation. Methyl estradiolpropanoate, bakuchiol, tetrahydrojasmonic acid, and growth factors received a recommendation grade of C. The remaining ingredients were assigned an inconclusive grade of recommendation due to lack of evidence. Cosmeceuticals included in the review had favorable safety profiles with few significant adverse events. The review analyzes numerous different ingredients to provide an evidence-based approach to decision-making for consumers and physicians on the use of cosmeceuticals for antiaging. Limitations to our review include a limited number of randomized controlled trials and a need for long-term data on each cosmeceutical's efficacy and safety. Future research is needed to establish the long-term effectiveness and safety of cosmeceuticals.

Improvement of adult female acne with a novel weekly oestradiol-loaded peel-off mask: a split-face placebo-controlled study

BACKGROUND

Adult female acne (AFA) is characterized by a relapsing eruption of acne in women aged ≥ 25 years. It can be slower to respond to traditional adolescent acne treatments. Usually, androgens promote acne by stimulating sebum production, while oestrogens have the -opposite effect by reducing sebum output when present in adequate quantities. Oestradiol is a female sex hormone that has its highest absolute serum levels and highest oestrogenic activity during the reproductive years. Peel-off facial masks have been suggested to intensify the effect of added active ingredients by forming an occlusive film after drying.

OBJECTIVES

To study the safety and efficacy of weekly topical oestradiol 0.05% in the treatment of AFA.

METHODS

Twenty women with AFA were subjected to once-weekly application of an oestradiol 0.05% mask or placebo mask to either side of their face for 8 weeks. An acne lesion count was performed at baseline, at each visit and 8 weeks post-treatment.

RESULTS

At the end of the treatment period, the treated side showed significant improvement in comedones, papules and pustules. Although lesion counts increased 2 months post-treatment, they remained significantly less common on the oestradiol-treated side compared with the side of the face treated with placebo. No side-effects were reported. Limitations included the small number of patients studied and the short follow-up period. The oestradiol effect was not studied at the cellular or molecular levels.

CONCLUSIONS

Topical oestradiol peel-off masks may be a promising convenient, safe and effective treatment for AFA.

Isoflavone-enriched soybean leaves (Glycine max) restore loss of dermal collagen fibers induced by ovariectomy in the Sprague Dawley rats

Phytoestrogens, such as isoflavones, are known for their capacity to simulate various physiological impacts of estrogen in the human body. Our research evaluated the effects of isoflavone-enriched soybean leaves (IESL) on collagen fiber loss prompted by ovariectomy in Sprague Dawley (SD) rats, thereby simulating menopausal changes in women. IESL, bolstered with an increased concentration of isoflavones through a metabolite farming process, contained a significantly higher amount of isoflavones than regular soybean leaves. Our results indicate that the administration of IESL can counteract the decrease in relative optical density and dermal thickness of collagen fibers caused by ovariectomy in SD rats, with more pronounced effects observed at higher isoflavone dosages. These outcomes suggest that soybean leaves rich in isoflavones may hold potential benefits in combating collagen degradation and skin aging symptoms related to menopause. Further research is needed to fully understand the exact molecular pathways at play and the potential clinical relevance of these findings.

Application of a skin and liver Chip2 microphysiological model to investigate the route-dependent toxicokinetics and toxicodynamics of consumer-relevant doses of genistein

The HUMMIC skin-liver Chip2 microphysiological system using EpiDerm™ and HepaRG and stellate liver spheroids was used to evaluate the route-specific metabolism and toxicodynamic effects of genistein. Human-relevant exposure levels were compared: 60 nM representing the plasma concentration expected after topical application of a cosmetic product and 1 μM representing measured plasma concentrations after ingesting soya products. Genistein was applied as single and repeated topical and/or systemic doses. The kinetics of genistein and its metabolites were measured over 5 days. Toxicodynamic effects were measured using transcriptional analyses of skin and liver organoids harvested on Days 2 and 5. Route-specific differences in genistein's bioavailability were observed, with first-pass metabolism (sulfation) occurring in the skin after topical application. Only repeated application of 1 μM, resembling daily oral intake of soya products, induced statistically significant changes in gene expression in liver organoids only. This was concomitant with a much higher systemic concentration of genistein which was not reached in any other dosing scenario. This suggests that single or low doses of genistein are rapidly metabolised which limits its toxicodynamic effects on the liver and skin. Therefore, by facilitating longer and/or repeated applications, the Chip2 can support safety assessments by linking relevant gene modulation with systemically available parent or metabolite(s). The rate of metabolism was in accordance with the short half-life observed in in vivo in humans, thus supporting the relevance of the findings. In conclusion, the skin-liver Chip2 provides route-specific information on metabolic fate and toxicodynamics that may be relevant to safety assessment.

The Relationship between Time, Race, and Estrogen Receptor Alpha in Estradiol-Induced Dermal Fibrosis

In the skin, estradiol (E2) promotes profibrotic and proinflammatory cytokines, contributing to extracellular matrix (ECM) deposition. However, the magnitude of the response differs. Using the human skin organ culture model, we evaluated donor characteristics and correlations that contribute to E2-induced interleukin-6 (IL-6), transforming growth factor beta 1 and 2 (TGFB1 and TGFB2), collagen IA2 (Col IA2), collagen IIIA1 (Col IIIA1), and fibronectin (FN) expressions. In vehicle- and E2-treated dermal skin tissue transcripts, we confirm differences in the magnitude; however, there were positive correlations between profibrotic mediators and ECM components 48 h after E2 treatment. Also, positive correlations exist between baseline and E2-induced TGFB1, IL-6, Col IIIA1, and FN transcripts. Since estrogen receptor alpha (ERA) can propagate E2's signal, we measured and detected differences in its baseline and fold change transcript levels, with a significant decline in baseline levels 48 h after incubation and an increase 48 h after E2 treatment. There was a trend to higher transcript levels in African American donors 24 h earlier. Finally, E2-induced ERA transcript levels negatively correlated with its own baseline levels and positively correlated with FN, TGFB1, and Col IA2 transcript levels. Therefore, our data suggest ERA, E2 exposure time, and race/ethnicity contribute to E2-induced dermal fibrosis.

Targeting estrogen signaling and biosynthesis for aged skin repair

Non-healing skin wounds are disproportionally prevalent in older adults. Current treatments do not account for the particularities of aged skin and result in inadequate outcomes. Overall, healing chronic wounds in the elderly remains a major unmet clinical need. Estrogens play a critical role in reproduction but also have important actions in non-reproductive organs. Estrogen biosynthesis and signaling pathways are locally activated during physiological wound healing, processes that are inhibited in elderly estrogen-deprived skin. Estrogen deprivation has been shown to be a critical mediator of impaired wound healing in both postmenopausal women and aged men, and topical estrogen application reverses age-associated delayed wound healing in both elderly men and women. These data indicate that adequate estrogen biosynthesis and properly regulated estrogen signaling pathways are essential for normal wound healing and can be targeted to optimize tissue repair in the elderly. However, due to fundamental questions regarding how to safely restore estrogen signaling locally in skin wounds, there are currently no therapeutic strategies addressing estrogen deficiency in elderly chronic wounds. This review discusses established and recent literature in this area and proposes the hypothesis that estrogen plays a pleiotropic role in skin aging and that targeting estrogen signaling and biosynthesis could promote skin repair in older adults.

Biotransformed soybean cream as a new nutraceutical for skin care: collagen stimulation in vitro and ex vivo

Treatments that attenuate the effects of hypoestrogenism in menopausal women have been gaining visibility. This study investigated the skin response to a phytoestrogen-enriched cosmetic formulation created by incorporating a biotransformed soybean extract (BE) into a cream-like matrix. Collagen-I expression was analyzed both in vitro (fibroblast cells) and ex vivo (skin explants). The results revealed an increased amount of collagen-I both in fibroblasts and human skin when treated with BE and BE-incorporated cream. Also, this collagen-I overexpression was inhibited by PHTPP, indicating a dependence on estrogen hormone receptor beta (ERβ) signaling. Moreover, BE was not harmful to skin microbiota, showing a promising nutricosmetic potential. Thus, this work presented a fully functional cream-like formulation that was shown to be safe and effectively increase collagen-I levels both in vitro and ex vivo.

Enhancing Skin Anti-Aging through Healthy Lifestyle Factors

Lifestyle health has been recognized as an evidence-based innovation that defines how everyday behaviors and routines influence the avoidance and therapy of illness and provides an important adjunctive component to overall health. Specifically, an approach with small changes over time can have a dramatic impact on the health and well-being of individuals not only, in general, but also can be applied to skin health. However, lifestyle health factors to improve skin well-being have not been discussed extensively and/or well promulgated. The narrative for this overview focuses on providing a summary for topic background information, but more importantly, presents four lifestyle factors that can improve dermal health [i.e., factor 1: nutrition—diet; factor 2: rest (sleep); factor 3: movement/physical exercise, and factor 4: social and community associations]. This was accomplished by identifying preceding journal reports/reviews covering especially the last five years (January 2018 to July 2023; 164 out of 205 references cited or 80%) using scientific search databases. The main conclusions of this overview encourage the concept that lifestyle health factors such as nutrition/diet, rest/sleep, movement/physical exercise, and community/social interactions support enhanced skin health and well-being with aging. Plus, social media interventions that aim to promote dietary, sleep and physical activity changes might be an application to improve skin health in the future.

Efficacy and Safety of the Genistein Nutraceutical Product Containing Vitamin E, Vitamin B3, and Ceramide on Skin Health in Postmenopausal Women: A Randomized, Double-Blind, Placebo-Controlled Clinical Trial

Skin aging is one of the most concerning issues that occur after menopause. The Genistein Nutraceutical (GEN) product, containing genistein, vitamin E, vitamin B3, and ceramide, has been formulated as a topical anti-aging product for improving the health of postmenopausal women's facial skin. This study aimed to investigate the efficacy and safety of the GEN product on postmenopausal women's facial skin. This randomized, double-blind, placebo-controlled trial randomly assigned 50 postmenopausal women to receive either the GEN product (n = 25) or the placebo (PLA) product (n = 25), topically applied twice daily for 6 weeks. The outcome assessments included multiple skin parameters related to skin wrinkling, color, hydration, and facial skin quality at baseline and week 6. The percentage mean changes or absolute mean changes, where appropriate, in skin parameters were compared between the two groups. The mean age of the participants was 55.8 ± 3.4 years. For skin wrinkling and skin color parameters, only skin redness was significantly higher in the GEN group when compared to the PLA group. Following the application of the GEN product, skin hydration increased while fine pores and their area decreased. Subgroup analysis of older women (age ≥ 56 years) with adequate compliance found significant differences between the two groups in the percentage mean changes of most skin wrinkle parameters. The GEN product has benefits for the facial skin of postmenopausal women, particularly those who are older. It can moisturize facial skin, lessen wrinkles, and enhance redness.

Factors Influencing Skin Aging and the Important Role of Estrogens and Selective Estrogen Receptor Modulators (SERMs)

The narrative for this overview focuses on updating the factors that influence skin aging and the important role estrogens and selective estrogen receptor modulators (SERMs) play in this process (mainly utilizing journal reports and reviews from the last four years). Estrogens have been known and studied for over a century. For many years, it has been recognized that estrogens are important in the maintenance of human skin. Women seek cosmetic and medical treatments to improve dermal health and physical characteristics to enhance their self-perception and inhibit skin aging, particularly in highly visible body areas. The goal: to retain estrogen’s positive benefits while aging and especially at/after menopause where estrogen-deficient skin contributes to the dramatic decline in skin health. In this overview, both background information and recent novel findings are included that cover aging (general mechanisms), skin aging, and factors that influence skin aging (intrinsic, extrinsic, skin microbiome and gut microbiome.) Plus, estrogen’s general role in maintaining skin health is presented through the classical estrogen receptors alpha (α) and beta (β) and non-classical (or non-genomic) estrogen receptor (G protein-coupled seven transmembrane receptor). More importantly, the various benefits of 17β-estradiol in skin health are examined (ie, skin collagen and elastin profiles that follow 17β-estradiol levels during aging and at/after menopause). Finally, a revision of information for estrogenic skin topical applications involving isoflavonoid compounds that act as SERMs, but are classified as endocrine disruptors, and a topical estrogen analog are explored to update the known and unknown characteristics of these treatments. Further study is warranted to understand the biological and molecular mechanisms by which estrogens support and enhance dermal health and wellbeing.

To clot, or not to clot: The dilemma of hormone treatment options for menopause

Untreated menopause may have serious health implications, but treatments can have dangerous side effects. We evaluate menopausal symptoms as well as available treatments -the routes of administration and their effect on blood coagulation. Menopausal females may experience hot flushes, vulva- and vaginal atrophy and osteoporosis. Many treatments are available to relieve these symptoms such as Conjugated Equine Estrogen and bioidentical hormones. The routes of administration include oral and transdermal. Hormones that are administered orally undergo a hepatic first pass metabolism. The by-products have a lower efficacy and possibly enhanced side effects. Furthermore, hormone treatments influence the coagulation cascade through coagulation factors or their regulators. Increased coagulation poses a risk for venous thromboembolism. Currently a definite conclusion on whether the side effects from hormone treatments exceed the risk of untreated menopause cannot be made. However, a more individualised approach to hormone treatments may be the most feasible solution to this dilemma.

Sex-Biased Control of Inflammation and Metabolism by a Mitochondrial Nod-Like Receptor

Mitochondria regulate steroid hormone synthesis, and in turn sex hormones regulate mitochondrial function for maintaining cellular homeostasis and controlling inflammation. This crosstalk can explain sex differences observed in several pathologies such as in metabolic or inflammatory disorders. Nod-like receptor X1 (NLRX1) is a mitochondria-associated innate receptor that could modulate metabolic functions and attenuates inflammatory responses. Here, we showed that in an infectious model with the human protozoan parasite, Leishmania guyanensis, NLRX1 attenuated inflammation in females but not in male mice. Analysis of infected female and male bone marrow derived macrophages showed both sex- and genotype-specific differences in both inflammatory and metabolic profiles with increased type I interferon production, mitochondrial respiration, and glycolytic rate in Nlrx1-deficient female BMDMs in comparison to wild-type cells, while no differences were observed between males. Transcriptomics of female and male BMDMs revealed an altered steroid hormone signaling in Nlrx1-deficient cells, and a “masculinization” of Nlrx1-deficient female BMDMs. Thus, our findings suggest that NLRX1 prevents uncontrolled inflammation and metabolism in females and therefore may contribute to the sex differences observed in infectious and inflammatory diseases.

Skin, hair and beyond: the impact of menopause

The skin is an endocrine organ and a major target of hormones such as estrogens, androgens and cortisol. Besides vasomotor symptoms (VMS), skin and hair symptoms often receive less attention than other menopausal symptoms despite having a significant negative effect on quality of life. Skin and mucosal menopausal symptoms include dryness and pruritus, thinning and atrophy, wrinkles and sagging, poor wound healing and reduced vascularity, whereas skin premalignant and malignant lesions and skin aging signs are almost exclusively caused by environmental factors, especially solar radiation. Hair menopausal symptoms include reduced hair growth and density on the scalp (diffuse effluvium due to follicular rarefication and/or androgenetic alopecia of female pattern), altered hair quality and structure, and increased unwanted hair growth on facial areas. Hormone replacement therapy (HRT) is not indicated for skin and hair symptoms alone due to the risk-benefit balance, but wider potential benefits of HRT (beyond estrogen's effect on VMS, bone, breast, heart and blood vessels) to include skin, hair and mucosal benefits should be discussed with women so that they will be able to make the best possible informed decisions on how to prevent or manage their menopausal symptoms.

Comparative effects of fractional radiofrequency and microneedling on the genitalia of postmenopausal women: Histological and clinical changes

OBJECTIVES

The authors aimed to evaluate clinical and histological changes induced by Fractional Radiofrequency (FRF) and microneedling in vulvar tissue.

METHODS

Thirty postmenopausal women were randomly divided into G1 (FRF) and G2 (microneedling) groups. Sub-ablative FRF was executed using disposable fractionated electrodes with an intensity of 8 mJ. Microneedling was performed using a derma roller system. The authors evaluated before and after treatment using the Vaginal Laxity Questionnaire (VLQ), EuroQol Five-Dimensional (EQ-5D) questionnaire, and the Blatt and Kupperman Menopausal Index (BKMI). Additionally, the authors performed biopsies of the labia majora for histological analysis pre- and post-treatment. Data were expressed as mean (± standard deviation). A paired t-test was used for intra-group comparison (pre- and post-treatment), with an independent t-test used to compare intergroup data (both pre- and post-treatment).

RESULTS

In the G1 group, the VLQ values showed differences compared to the pre-treatment values with the data obtained 60 days after the beginning of the sessions (p = 0.01). Similarly, the data changes of the G2 group proved to be significant (p = 0.001) across the same time interval. In comparing the groups, VLQ values were not different (p > 0.05). Regarding histological analysis, FRF demonstrated improvement concerning the number of fibroblasts, blood vessels, and fatty degeneration (p < 0.05) compared to the control. Additionally, FRF and microneedling samples showed higher type III collagen and vimentin expression in the immunohistochemical analysis (p < 0.05).

CONCLUSIONS

The therapies were found to be effective in treating the flaccidity of the female external genitalia. Additionally, histological changes were observed after interventions suggesting collagen remodeling.

Improvement of Biophysical Skin Parameters of Topically Applied Fermented Soybean Extract-Loaded Niosomes with No Systemic Toxicity in Ovariectomized Rats

Despite the known beneficial impacts of estrogen used as hormone replacement therapy to ameliorate signs of skin aging in postmenopausal women, its compliance rates are low. A significant amount of estrogen may be absorbed into the blood circulation and can lead to systemic actions. Soy isoflavone exhibits biological activities similar to synthetic estrogen because it is a heterocyclic phenolic compound. The disadvantage of most topical ingredients based on isoflavone is that they contain biologically inactive glycoside forms, which must be converted to a readily absorbed aglycone for the topical application. The purposes of this study were to develop niosomes-loaded Aspergillus oryzae-fermented soybean extract (FSE) to enhance skin absorption with proven systemic side effect compared to estrogen application. Skin hydration and viscoelasticity of 75 days post-ovariectomized (OVX) Wistar rats following 84-day topical treatment with various tested gel formulations containing fermented soybean extract (FSE) were evaluated. The tested formulations were gel + FSE nanoniosomes, gel + FSE microniosomes, gel + FSE (200 µg FSE/9 cm²/rat), gel + blank nanoniosomes (a negative control), and gel + 17β-estradiol (E2) nanoniosomes (a positive control, 20 µg E2/9 cm²/rat). Changes in vaginal cornifications and weights of uteri, livers, and kidneys in the OVX rats and signs of primary skin irritation in the rabbits were evaluated for their toxicities. Results showed that FSE-loaded nanoniosomes improved the skin hydration and viscoelasticity better than gel + FSE microniosomes and gel + FSE, respectively, but lower than those of gel + E2 nanoniosomes (p < 0.05). Unlike all gel + E2 nanoniosomes, the FSE formulations showed no changes in vaginal cells and weights of uteri, livers, and kidneys and no signs of skin irritation. In conclusion, The FSE niosome-based gels should be promising candidates for delivering phytoestrogens against signs of skin aging with no systemic toxicities.

Cyclic Adenosine Monophosphate Eliminates Sex Differences in Estradiol-Induced Elastin Production from Engineered Dermal Substitutes

Lack of adult cells' ability to produce sufficient amounts of elastin and assemble functional elastic fibers is an issue for creating skin substitutes that closely match native skin properties. The effects of female sex hormones, primarily estrogen, have been studied due to the known effects on elastin post-menopause, thus have primarily included older mostly female populations. In this study, we examined the effects of female sex hormones on the synthesis of elastin by female and male human dermal fibroblasts in engineered dermal substitutes. Differences between the sexes were observed with 17β-estradiol treatment alone stimulating elastin synthesis in female substitutes but not male. TGF-β levels were significantly higher in male dermal substitutes than female dermal substitutes and the levels did not change with 17β-estradiol treatment. The male dermal substitutes had a 1.5-fold increase in cAMP concentration in the presence of 17β-estradiol compared to no hormone controls, while cAMP concentrations remained constant in the female substitutes. When cAMP was added in addition to 17β-estradiol and progesterone in the culture medium, the sex differences were eliminated, and elastin synthesis was upregulated by 2-fold in both male and female dermal substitutes. These conditions alone did not result in functionally significant amounts of elastin or complete elastic fibers. The findings presented provide insights into differences between male and female cells in response to female sex steroid hormones and the involvement of the cAMP pathway in elastin synthesis. Further explorations into the signaling pathways may identify better targets to promote elastic fiber synthesis in skin substitutes.

A role for estrogen in skin ageing and dermal biomechanics

The skin is the body's primary defence against the external environment, preventing infection and desiccation. Therefore, alterations to skin homeostasis, for example with skin ageing, increase susceptibility to skin disease and injury. Skin biological ageing is uniquely influenced by a combination of intrinsic and extrinsic (primarily photoageing) factors, with differential effects on skin structure and function. Interestingly, skin architecture rapidly changes following the menopause, as a direct result of reduced circulating 17β-estradiol. The traditional clinical benefit of estrogens are supported by recent experimental data, where 17β-estradiol supplementation prevents age-related decline in the skin's structural and mechanical properties. However, the off-target effects of 17β-estradiol continue to challenge therapeutic application. Here we discuss how ageing alters the physiological and structural properties of the dermal extracellular matrix, and explore how estrogen receptor-targeted therapies may restore the mechanical defects associated with skin ageing.

Hormone treatment and UVB exposure influences on female mice regarding skin physiological parameters, biochemical parameters and organ histology

Females require at a certain period of life the administration or supplementation of specific hormones (estrogen, progesterone), for various needs, such as: prevention of unwanted pregnancies, decreased menstrual bleeding, dysmenorrhea and pelvic pain in endometriosis, alleviation of symptoms associated with menopause, regulation of certain skin processes related to acne or aging and others. Also, hormones could act as oncogenes being known eloquent examples of estrogens labeled both as promoters of cell specific alteration or as mutagenic agents. The use of hormones and exposure to solar radiation is expected to cause a number of adverse changes to the body, especially due to their association with malignant processes. The current study was purported as a basis for understanding certain processes that occur with the administration of hormones and exposure to ultraviolet B (UVB) radiation. The animal model was made on healthy adult female BALB/c mice, which were separated into groups and treated with Ethinylestradiol (EES), Levonorgestrel (LNG) and their combination in the presence of UVB radiation. Changes in skin physiological parameters were analyzed by non-invasive methods, biochemical parameters related to changes in blood circulating system were evaluated by standard methods and histopathological analysis was conducted to point out the changes at the level of the internal body. Measurement of skin parameters such as erythema, melanin, skin hydration, has highlighted some changes in hormone-treated and exposed to UVB radiation groups which were significant only in the case of erythema. Biochemical parameters showed variations in terms of liver enzymes in groups treated with active substances. Histologically, aspects of internal organs revealed significant changes in the group treated with EES and LNG and exposed to UVB radiation.

Impact of progesterone on skin and hair in menopause - a comprehensive review

In clinical practice, micronized progesterone (MP) is frequently recommended to treat signs and symptoms of skin and hair aging in menopausal women. The aim of this comprehensive review was to evaluate whether topically or systemically applied MP may effectively prevent or slow down signs of skin and hair aging. Three out of six identified studies reported an impact of MP on skin aging markers in menopausal women. Of these, two studies reported a benefit: one for topically applied MP, another for systemically applied combined menopausal hormone therapy (MHT) comprising MP as progestogen for endometrial protection. Tolerability and safety of MP were good. However, there was no study investigating the impact of MP on menopausal scalp hair. In conclusion, delay of skin aging comprises lifestyle adjustment, antioxidants, and several esthetic procedures. In menopausal women, MHT displays beneficial effects on skin aging. There is poor quality but promising scientific evidence for MP displaying anti-aging skin effects in menopausal women. However, good quality studies are needed.

Effects of soy isoflavones extract on the lipid profile and uterus in ovariectomized rats

AIM

Although soy isoflavones (ISO) have been shown to relief postmenopausal symptoms, it remains inconclusive whether ISO can improve lipid-profile without uterotrophic effects under estrogen-deficiency. Thus, we investigated the effects of ISO on lipid-profile and uterus of ovariectomized (Ovx) rats.

MATERIALS AND METHODS

Twenty-five adult rats were Ovx or Sham-operated (Sham) and assigned into five groups: Sham and Ovx groups, administered with vehicle solutions; Ovx-E, treated with 10 µg/kg of 17β-Estradiol; Ovx-ISO, treated with 200 mg/kg of ISO; Ovx-E + ISO, treated with estradiol + ISO combined. After fifty days of treatments, rats were euthanized and uterine horns were processed for histomorphometry or to collagen fibers and glycosaminoglycans evaluations. Blood samples were collected to evaluate levels of triglycerides, total cholesterol (TC) and its fractions (HDL/VLDL). Data were subjected to statistical analysis (p < .05).

RESULTS

Uterus weight was lower in Ovx group than the Sham and Ovx-E groups, whereas it was similar between Ovx and Ovx-ISO groups. Histomorphometry showed atrophic uterus in Ovx and Ovx-ISO groups, whereas uterotrophic effects were noticed in Ovx-E and Ovx-E + ISO groups. Collagen fibers-birefringence was higher in Sham, Ovx, and Ovx-ISO groups than in Ovx-E and Ovx-E + ISO groups. Sulfated glycosaminoglycans content was similar among Sham, Ovx, and Ovx-ISO groups, while it was higher in estrogen-treated groups; total glycosaminoglycans content was similar among groups. TC and HDL was higher in Ovx-ISO group, whereas VLDL and triglycerides levels was higher in Ovx-E + ISO group and similar among other groups.

CONCLUSION

Soy isoflavones at 200 mg/kg have slight beneficial effects on lipid-profile without uterotrophic effects in Ovx rats.

Menopause and the Skin: Old Favorites and New Innovations in Cosmeceuticals for Estrogen-Deficient Skin

Estrogen is a pivotal signaling molecule; its production is regulated by the expression of the aromatase (CYP19A1) gene from ovarian and peripheral tissue sites, and it is transmitted via estrogen receptors to influence many important biological functions. However, the narrative for this overview focuses on the decline of 17β-estradiol levels from ovarian sites after menopause. This estrogen-deficient condition is associated with a dramatic reduction in skin health and wellness by negatively impacting dermal cellular and homeostatic mechanisms, as well as other important biological functions. The changes include loss of collagen, elastin, fibroblast function, vascularity, and increased matrix metalloproteinase(s) enzymatic activities, resulting in cellular and extracellular degradation that leads to dryness, wrinkles, atrophy, impaired wound healing/barrier function, decreased antioxidant capacity [i.e., defense against reactive oxygen species (ROS) and oxidative stress], decreased attractiveness and psychological health, and increased perception of aging. While topical estrogen may reverse these changes, the effects of today's low-dose systemic hormone treatments are not well established, raising the need for more concentrated local administration of hormones or newer cosmeceutical agents such as selective estrogen receptor modulators (SERMs), including phytoestrogens that have become major active ingredients for skin care products, especially when addressing estrogen-deficient skin. Two example compounds are presented, an analog of resveratrol (i.e., 4'-acetoxy resveratrol) and the isoflavonoid equol, both of which are involved in a variety of biochemical/molecular actions and mechanisms, as demonstrated via in vitro and clinical studies that enhance human dermal health, especially in estrogen-deficient skin.

Sexual dimorphism in atrophic effects of topical glucocorticoids is driven by differential regulation of atrophogene REDD1 in male and female skin

Topical glucocorticoids, well-known anti-inflammatory drugs, induce multiple adverse effects, including skin atrophy. The sex-specific effects of systemic glucocorticoids are known, but sexual dimorphism of therapeutic and side effects of topical steroids has not been studied. We report here that female and male mice were equally sensitive to the anti-inflammatory effect of glucocorticoid fluocinolone acetonide (FA) in ear edema test. At the same time, females were more sensitive to FA-induced skin atrophy. We recently reported that REDD1 (regulated in development and DNA damage 1) plays central role in steroid atrophy. We found that REDD1 was more efficiently activated by FA in females, and that REDD1 knockout significantly protected female but not male mice from skin atrophy. Studies using human keratinocytes revealed that both estradiol and FA induced REDD1 mRNA/protein expression, and cooperated when they were combined at low doses. Chromatin immunoprecipitation analysis confirmed that REDD1 is an estrogen receptor (ER) target gene with multiple estrogen response elements in its promoter. Moreover, experiments with GR and ER inhibitors suggested that REDD1 induction by these hormones was interdependent on functional activity of both receptors. Overall, our results are important for the development of safer GR-targeted therapies suited for female and male dermatological patients.

The role of bioidentical hormone replacement therapy in anti-aging medicine: a review of the literature

The changes in skin and overall appearance that occur with increasing age can be partly attributed to declining hormone levels. While hormonal deficiencies are most commonly associated with postmenopausal females, males are also subject to age-related testosterone decline and may benefit from replacement of deficient hormones. However, great disparities exist between the recommendations of scientific societies and actual use of hormone supplements in aging patients. The purpose of this literature review is to discuss the role of hormones in the aging process of the skin, explain the safety profile of hormone replacement therapy, specifically discussing the superiority of bioidentical hormones, and highlight the benefits of hormone replacement in anti-aging of the skin. In summary, this literature review suggests that hormone replacement with bioidentical hormones is a safe and effective way to prevent skin aging.