Retinoids: active molecules influencing skin structure formation in cosmetic and dermatological treatments

In Vitro and In Vivo Assessment of an Innovative Peeling System with Azelaic and Tranexamic Acids for Targeted Hyperpigmentation Reduction

INTRODUCTION

Melanin, derived from tyrosine, plays a pivotal role in skin pigmentation through melanogenesis. Disruptions in this process lead to hyperpigmentation, a condition affecting skin tone and quality of life. Current treatments, including chemical peels, have limitations, highlighting the need for novel solutions. Here, we present an innovative peeling system, comprising a masque and moisturizer, formulated with a novel blend of acids, including azelaic acid (AZA) and tranexamic acid (TXA), alongside known brightening and penetration-enhancing agents for a comprehensive solution to target hyperpigmentation.

METHODS

In vitro studies assessed the ability of the novel moisturizer to inhibit ultraviolet-A (UVA)-induced melanin accumulation in human melanocytes. In a single-center, controlled study, we assessed the efficacy of the peeling system in 33 healthy female participants aged 30-55 years with moderate-to-severe hyperpigmentation over a 6-week treatment period. Skin condition was assessed using clinical photography, 3D skin topography, and clinical expert evaluation (CEE) at baseline and 6 weeks post-treatment. Participants completed a self-evaluation questionnaire at 6 weeks post-treatment.

RESULTS

In vitro findings demonstrated a concentration-dependent inhibition of melanin accumulation by the novel moisturizer. In vivo, significant reductions in dark spot number, area, and perimeter were observed at week 6, along with improvements in skin homogeneity, contrast, and brightness. Skin tone and roughness parameters also improved significantly from baseline. These findings were supported by self-evaluation findings and improvements in CEE parameters.

CONCLUSION

These data provide evidence for the efficacy of the innovative peeling system in reducing the appearance of hyperpigmentation over a 6-week treatment regimen in females with healthy skin and moderate-to-severe hyperpigmentation. The inclusion of AZA and TXA within the peeling system, along with active brightening and penetration-enhancing ingredients, may have synergistically facilitated the observed improvements. This multifaceted approach may address hyperpigmentation at the source, contributing to overall improvements in the appearance of the skin.

A Scoping Review on Melasma Treatments and Their Histopathologic Correlates

Melasma is an incredibly common dyschromic disorder, mostly impacting women with skin of color. There are three variants of melasma based on the depth of pathologic involvement: epidermal, mixed, and dermal. While there are many treatments for melasma, there is a paucity of research on melasma treatments and their dermatopathological correlates. A scoping review was conducted of all human trials on melasma with histopathologic analysis, including 37 trials in the final analysis. Most studies were conducted on women with a Fitzpatrick skin type of III or greater. Strong histologic evidence supports the utilization of retinols/retinoids for epidermal melasma and microneedling for dermal melasma. There is a paucity of trials conducted on melasma utilizing histologic correlates, and fewer still that are comprehensive to include analyses on quality of life.

Colloidal-fibrillar composite gels demonstrate structural reinforcement, secondary fibrillar alignment, and improved vascular healing outcomes

Many biological tissues contain colloids within a fibrillar structure. Here, we develop and characterize colloidal-fibrillar scaffolds through examination of the effects of relative colloid and fiber ratios within a fibrin-based model system composed of fibrin-based nanoparticles (FBNs) within a natural fibrin scaffold. At lower concentrations, FBNs primarily integrate into the fibrillar fibrin matrix, strengthening it. At high concentrations, colloid-colloid interactions dominate and FBNs primarily form a highly aligned secondary structure that does not strengthen the fibrillar matrix. At intermediate concentrations, both reinforcement of the fibrin matrix and colloid-colloid interactions are observed. Our characterization of this colloidal-fibrillar system provides insight into new avenues for wound healing biomaterial development. Using structural and mechanical results, we developed a biomimetic surgical sealant. When applied to a vascular healing model, FBN gel resulted in improved vessel healing. This colloidal-fibrillar composite can greatly improve healing outcomes and should be applied to other tissues.

A new ex vivo human skin model for the topographic and biological analysis of cosmetic formulas

OBJECTIVE

Existing methods to evaluate skin care products suffer limitations. This is the case for ex vivo skin explants, a first-choice 3D model. While essential to analyse mid- to long-term biological effects, this classical model hinders assessing microrelief variations. To circumvent these limitations, we developed an ex vivo PERFused EXplant setup (Perfex) that maintains the outer skin surface in the open air, closely mirroring physiological conditions.

METHODS

A custom-designed reservoir enables perfusing the dermal side of explants with buffered, temperature-controlled medium, while the epidermis is subjected to "normal" conditions. Skin tension and characteristics of the stratum corneum, microrelief, histology and immunohistology (collagen types I and III, elastin and fibrillin-1) were analysed and compared to those of explants maintained under conventional conditions or in vivo skin. The effects of skin care formulas intended to induce short- and/or mid- to long-term effects were also assessed.

RESULTS

Skin explants maintained with the Perfex setup exhibit characteristics (firmness, elasticity, hydration and barrier function) closer to those of in vivo skin than with conventional conditions. Moreover, Perfex-maintained explants present no alteration in histology after 7 days and slight variation in the expression of key protein markers. Microrelief characteristics also remain mostly stable over 7 days. Formula applications corroborate that skin tensor-containing products primarily induce short-term changes in the microrelief, while those with biologically active ingredients mainly lead to mid- to long-term effects on the histology and expression of molecular markers. Furthermore, maintaining skin explants with a physiologically relevant skin surface enabled analysing the relationship between microrelief and key markers, showing that fibrillin-1 is the protein most correlated with microrelief characteristics.

CONCLUSIONS

The Perfex setup allows for similar preservation of skin explant histology and key protein expression as the conventional system, yet it maintains a skin surface close to that of in vivo skin. Therefore, it is valuable to analyse both the short- and mid- to long-term impacts of skin care formulas and better comprehend their effects. The Perfex system also offers a new tool for investigating fundamental questions, such as the link that can exist between dermal proteins and skin surface properties.

Usage Frequency and Ecotoxicity of Skin Depigmenting Agents

Background/Objectives: Depigmenting cosmetic products are a fast-growing segment of the health products market, driven by consumer demand to address skin hyperpigmentation. Simultaneously, interest in products with a reduced environmental impact is increasing. However, the potential environmental risks, especially in aquatic ecosystems, of depigmenting products remain unexplored. This study assesses the usage frequency of skin depigmenting agents in cosmetic products and compiles data on the biodegradability and acute aquatic toxicity of the most prevalent compounds. Methods: A market analysis of Portuguese pharmacies and parapharmacies in 2022 identified prevalent depigmenting agents. Scientific evidence on their biodegradability and acute aquatic toxicity was compiled, and when data was unavailable, in silico predictions were conducted. Results: The study identified the ten most-used depigmenting agents in cosmetic products, including hydroxy/keto acids, as well as vitamin C and derivatives, with a usage frequency surpassing 50%. While most were naturally derived and showed low environmental risk, synthetic and highly lipophilic depigmenting agents found in 35 of 70 products (ascorbyl tetraisopalmitate/tetrahexyldecyl ascorbate and resorcinol derivatives) showed a higher potential for environmental hazard. Conclusions: The findings underscore the need for further research on the presence of these cosmetic ingredients in aquatic ecosystems and a reassessment of regulatory frameworks concerning their environmental impact. Mitigation strategies should emphasize biodegradable alternatives, renewable sources, and molecular modifications to reduce toxicity while maintaining depigmenting efficacy and skin safety. This study provides original insights into commonly used depigmenting agents in the health products market and their chemical structures, offering valuable opportunities for innovation in chemical/pharmaceutical industries.

Recommendations to Improve Outcomes in Acne and Acne Sequelae: A Focus on Trifarotene and Other Retinoids

Acne vulgaris affects nearly 50 million people in the USA, ranking as the eighth most prevalent disease globally. This chronic inflammatory skin condition often results in sequelae, including atrophic acne scars, acne-induced macular erythema and acne-induced hyperpigmentation, impacting patients' quality of life. This commentary article reviews the use of topical retinoids, with a particular emphasis on trifarotene cream 0.005%, for managing both acne and acne sequelae. Topical retinoids are considered central to improving treatment outcomes because of their established efficacy, safety and tolerability. Adapalene, tretinoin and tazarotene have demonstrated efficacy in reducing acne and acne sequelae in several studies. Trifarotene has been extensively studied in Phase 3 trials, demonstrating notable success in treating mild-to-moderate acne. Recently, two large-scale, randomized, blinded, Phase 4 clinical trials investigated trifarotene cream 0.005% in patients with atrophic acne scarring and acne-induced hyperpigmentation across all Fitzpatrick phototypes. The START study found that there was a greater reduction in total atrophic acne scar count in the trifarotene group compared with the vehicle group at Week 24 (55.2% vs 29.9%) with statistical significance established as early as Week 2 (P = 0.001). Based on this evidence, we recommend that topical retinoids should be introduced as first-line therapy for the treatment of acne and acne sequelae. Retinoids should be implemented into a treatment routine as early as possible, especially for patients with darker Fitzpatrick phototypes or patients at risk of atrophic acne scarring. Furthermore, retinoids should be incorporated within a comprehensive skincare regimen that includes adequate photoprotection when treating patients with darker Fitzpatrick phototypes. Finally, management of acne and acne sequelae should include maintenance therapy with topical retinoids. This article supports the American Academy of Dermatology's call for acne sequelae treatment guidance and emphasizes the need for continued research to optimize patient care.

Cosmetic retinoid use in photoaged skin: A review of the compounds, their use and mechanisms of action

The inevitable attrition of skin due to ultraviolet radiation, termed photoaging, can be partially restored by treatment with retinoid compounds. Photoaged skin in lightly pigmented individuals, clinically presents with the appearance of wrinkles, increased laxity, and hyper- and hypopigmentation. Underlying these visible signs of ageing are histological features such as epidermal thinning, dermal-epidermal junction flattening, solar elastosis and loss of the dermal fibrillin microfibrillar network, fibrillar collagen and glycosaminoglycans. Retinoid compounds are comprised of three main generations with the first generation (all-trans retinoic acid, retinol, retinaldehyde and retinyl esters) primarily used for the clinical and cosmetic treatment of photoaging, with varying degrees of efficacy, tolerance and stability. All-trans retinoic acid is considered the 'gold standard' for skin rejuvenation; however, it is a prescription-only product largely confined to clinical use. Therefore, retinoid derivatives are readily incorporated into cosmeceutical formulations. The literature reported in this review suggests that retinol, retinyl esters and retinaldehyde that are used in many cosmeceutical products, are efficacious, safe and well-tolerated. Once in the skin, retinoids utilize a complex signalling pathway that promotes remodelling of photoaged epidermis and dermis and leads to the improvement of the cutaneous signs of photoaging.

Dually functionalized dendrimer for stimuli-responsive release of active ingredients into the skin

The skin, our largest organ, protects against environmental dangers but is vulnerable to various conditions like infections, eczema, dermatitis, psoriasis, skin cancer, and age-related collagen and elastin degradation. Its outer layer, the water-impermeable epidermis, presents challenges for passive drug delivery to the lower living layers of the skin. An ideal dermal delivery system should penetrate the epidermis and release treatments over time. We report a stimuli-activated nanocarrier that slowly releases active ingredients under skin-specific conditions. Using a fourth-generation polyamidoamine (PAMAM), dendrimer functionalized with poly(2-ethyl-2-oxazoline) and palmitoyl pentapeptide-4, we show a controlled release of biologically active therapeutics into the dermis of the skin for 24 h. Ex vivo studies demonstrate that our nanocarrier system delivers cargo to the dermis and is non-toxic to skin fibroblasts. As a proof of principle, we demonstrate a system that effectively enhances collagen production in human dermal fibroblasts by co-delivering all-trans retinol and palmitoyl pentapeptide-4. Our nanosystem surpasses the effects of individual components. This nanocarrier offers a promising approach for targeted dermal delivery, potentially improving treatment efficacy for various skin conditions while minimizing adverse effects associated with traditional formulations. STATEMENT OF SIGNIFICANCE: In this manuscript we introduce a stimuli-responsive nanocarrier based on a G4-PAMAM dendrimer functionalized with poly(2-ethyl-2-oxazoline) (POZ) and palmitoyl pentapeptide-4, designed to deliver biomolecules specifically to the skin. The nanocarrier enables controlled, stimuli-triggered release under skin-specific conditions (pH 5, 37 °C), enhancing dermal penetration and minimizing release at neutral pH or lower temperatures. This work improves traditional dendrimer systems by reducing toxicity through POZ, ensuring controlled delivery without invasive techniques like iontophoresis, and co-delivering both a small molecule (all-trans-retinol) and a collagen-stimulating peptide for enhanced therapeutic effects. This system addresses major drug delivery challenges, sets a new precedent for safer, multifunctional nanomaterials, and advances dendrimer chemistry, opening new possibilities in targeted therapies, skin treatments, and materials science.

Biological Activities and Phytochemical Screening of Thuja occidentalis Extracts with In Silico Approaches

The evergreen coniferous tree Thuja occidentalis is a member of the Cupressaceae family. This study included biological, cytotoxic, and in silico docking analyses in addition to a phytochemical composition analysis of the plant leaves and stem ethanolic extracts. The extracts' in vitro cytotoxicity efficacy against various cancer cell lines was examined. Additionally, certain phytochemical compounds were identified by gas chromatographic analysis and subsequently assessed in silico against anticancer molecular targets. Also, their antiviral effect was assessed. Good cytotoxic activity was demonstrated by plant extracts against the lung and colorectal cancer cell lines. With half-maximal inhibitory concentration values of 18.45 μg/mL for the leaf extract and 33.61 μg/mL for the stem extract, apoptosis and S-phase arrest was observed in the lung cancer cell line. In addition, the leaf extract demonstrated effective antiviral activity, with suppression rates of 17.7 and 16.2% for the herpes simplex and influenza viruses, respectively. Gas chromatographic analysis revealed the presence of relevant bioactive components such as Podocarp-7-en-3β-ol, 13β-methyl-13-vinyl, Megastigmatrienone, and Cedrol, which were tested in silico against anticancer molecular targets. Our findings suggest that plant ethanolic extracts may have potential therapeutic uses as anticancer drugs against lung cancer in addition to their antiviral properties, which opens up further avenues for more investigation and applications.

Silybum marianum Extract: A Highly Effective Natural Alternative to Retinoids to Prevent Skin Aging Without Side Effects

BACKGROUND

Vitamin A, or retinol, is one of the most effective antiaging molecules, but it presents issues with photo-sensitivity and irritation. Alternatives are emerging, but have so far been less effective.

OBJECTIVE

Here, we present a Silibum marianum extract (SME) as a retinol-like ingredient providing both safety and efficacy. SME was compared to the reference compound, retinol, and to the main alternative, bakuchiol.

METHODS

Skin explants from a 58-year-old donor were treated with pure retinol (0.1%), bakuchiol (0.2%), or SME (0.8%). After 5 days, collagen and hyaluronic acid levels were analyzed. A placebo-controlled study involving 57 volunteers was also conducted, with products applied twice daily for 56 days. Results were measured by AEVA-HE and VISA.

RESULTS

Levels of collagen III were significantly increased by SME, by 23% and 16% compared to bakuchiol and retinol respectively. Compared to bakuchiol, SME treatment increased hyaluronic acid production by 36%. In clinical tests, SME had a significantly stronger anti-wrinkle effect than bakuchiol-reducing the number of wrinkles on the forehead by 21% and their circumference by 17%-producing effects similar to retinol, and better than bakuchiol. In the self-assessment, 43% of volunteers reported discomfort while using retinol compared to 0% for the SME formulation. By enhancing levels of collagen III-the youth collagen-and hyaluronic acid in the skin, SME paves the way for the maturation of collagen I fibrils and skin plumping.

CONCLUSION

With its stronger efficacy compared to bakuchiol and enhanced safety profile compared to retinol, SME may be the next generation of natural alternatives to retinoids.

Effects of Retinol, Natural Pea Peptide and Antioxidant Blend in a Topical Formulation: In Vitro and Clinical Evidence

INTRODUCTION

Retinol has a long history of treating skin conditions, including photoaging. However, skin irritation with repeated use of retinol is well documented. The present study assessed the effectiveness of a novel topical formulation, referred to as retinol topical formulation (RTF), to improve the quality of skin health. The RTF was composed of a low dose retinol, a synthetic retinoid ester, a pea peptide, and an antioxidant blend.

METHODS

In vitro assessment of RTF on human skin co-cultures (human keratinocytes, melanocytes, and dermal fibroblasts) identified gene expression levels and skin biomarkers after 24 h exposure. An 8-week clinical study was conducted to evaluate once-nightly application of the RTF for short-term and long-term benefits in 30 adult subjects between 35 and 70 years of age (21 female, 9 male). Skin evaluations were conducted via bioinstrumentation (for hydration, transepidermal water loss and elasticity) and at 0, 1-, 2-, 4-, and 8-week self-assessment questionnaires and photo-imaging analysis were performed.

RESULTS

RTF treatment of skin in vitro co-cultures upregulated aquaporin-3, PER1, collagen, and elastin, and downregulated expression of MMP1 and the pigmentation genes TYRP1 and MITF. The clinical assessment significantly improved hydration, transepidermal water loss, and elasticity along with incremental but significant increases in nine skin parameters (hydration, clarity, radiance/glow, smoothness, brightness, texture, appearance of pores, dark spots/hyperpigmentation, and skin tone evenness from baseline) with continuous use over 8 weeks compared to baseline values.

CONCLUSIONS

The RTF in vitro analysis showed significant positive changes for several skin biomarkers, and the clinical assessment showed RTF significantly improved the visible signs of dermal aging, without irritation.

Comparing Tretinoin to Other Topical Therapies in the Treatment of Skin Photoaging: A Systematic Review

BACKGROUND

Many morphological and histological changes take place in aging skin. Topical tretinoin is the gold standard anti-aging agent used to reduce signs of aging through stimulation of epidermal growth and differentiation and inhibition of collagenase.

OBJECTIVE

The aim of this systematic review is to summarize studies evaluating the efficacy of tretinoin compared with other topical medications and cosmeceuticals in reducing the appearance of skin aging.

METHODS

A systematic review was conducted following the Preferred Reporting Items for Systematic Review and Meta-analysis (PRISMA) guidelines. The literature search was conducted using the PubMed and Embase databases from conception to December 2023. Studies were included if they compared anti-aging outcomes of topical medications with those of topical tretinoin (also called all-trans retinoic acid and retinoic acid). Studies were excluded if they compared non-topical anti-aging treatments with tretinoin or were conducted on animal models.

RESULTS

The literature search resulted in 25 studies that met all inclusion and exclusion criteria. The most common study comparators to tretinoin included other forms of vitamin A. Outcomes were reported on the basis of visual reduction of aging signs, histological assessment of the epidermis and dermis, and protein expression. Although comparators to tretinoin had variable efficacy (greater in 7 studies, equivalent in 13 studies, and less in 3 studies), most studies found the comparator to be less irritating and better tolerated by patients than tretinoin.

DISCUSSION

Tretinoin is currently the gold standard therapy for the treatment of photoaging, but its poor tolerability often limits its use. Unfortunately, given that most studies comparing topical therapies with tretinoin are of poor quality and/or demonstrate bias, there is a lack of substantial evidence to support an alternative first-line therapy. However, given there are some data to support the efficacy of retinoid precursors, namely retinaldehyde, pro-retinal nanoparticles, and conjugated alpha-hydroxy acid and retinoid (AHA-ret), these agents can be considered a second-line option for anti-aging treatment in patients who cannot tolerate tretinoin.

Exploring the Therapeutical Potential of Asparagopsis armata Biomass: A Novel Approach for Acne Vulgaris Treatment

Acne vulgaris, a high-prevalence skin condition afflicting people, persists as a significant challenge in the absence of effective treatments and emerging antibiotic resistance. To address this pressing concern, exploration of innovative approaches is of the utmost importance. Asparagopsis armata, an invasive red seaweed renowned for its diverse array of bioactive compounds, emerges as a promising candidate. This study seeks to elucidate the potential utility of A. armata biomass in the treatment of acne vulgaris. Crude extracts were obtained through solid-liquid extraction, and fractions were obtained using liquid-liquid extraction. The analyzed bioactivities included antioxidant, antimicrobial, and anti-inflammatory. Also, chemical characterization was performed to identify free fatty acids and compounds through LC-MS and elements. The present findings unveil compelling attributes, including anti-Cutibacterium acnes activity, cytotoxic and non-cytotoxic effects, antioxidant properties, and its ability to reduce nitric oxide production with consequent anti-inflammatory potential. Additionally, chemical characterization provides insights into its mineral elements, free fatty acids, and diverse compounds. The observed antimicrobial efficacy may be linked to halogenated compounds and fatty acids. Cytoprotection appears to be associated with the presence of glycerolipids and glycosylated metabolites. Furthermore, its antioxidant activity, coupled with anti-inflammatory properties, can be attributed to phenolic compounds, such as flavonoids. This study underscores the potential of A. armata as a natural ingredient in skincare formulations, offering an important contribution to the ongoing battle against acne vulgaris.

Green seaweed-derived polysaccharides: Insights into various bioactivities for biomedical applications

This research work explores the physicochemical characteristics and biological functions of polysaccharides extracted from four selected green seaweed species: Ulva lactuca (UL), Halimeda opuntia (HO), Caulerpa racemosa (CR), and Chaetomorpha antennina (CA). The extracts were investigated for cell-based bio-activities (i.e., cytotoxicity, cell proliferation and migration) using three cell lines (HDF, HaCaT, RAW264.7) reflecting cell models involved in wound healing, as well as anticoagulant activity. Ulvans from UL significantly increased HaCaT (at 0.06 μg/μL) and HDF (at 0.5 μg/μL) cell proliferation. In addition, extracts from CA showed the highest cell migration ability using HDF and HaCaT cells. UL (all fractions), HO-2A, CR-1B, CA-1A and CA-2B fractions improved phagocytosis. Furthermore, RAW264.7 cells treated with fraction CA-1A produced significantly more intracellular NO (pro-inflammatory) within 24 h compared to control (LPs). Green seaweed extracts CA-2A and UL-1A resulted in lower expression of the pro-inflammatory cytokine TNF-α in skin cells (HDF, HaCaT). Caulerpa cold-extracted polysaccharides possessed higher anticoagulant properties. The Ulva (1,4-linked α-l-rhamnose, β-d-glucuronic acid, l-iduronic acid) and CA extracts are promising sources of bioactive therapeutic agents. Our data provide useful insights into the possible biomedical benefits of selected polysaccharides mixtures (i.e., ulvan, sulfated or/and pyruvylated β-d-galactans, sulfated xyloarabinogalactan) for food, pharmaceutical, and biotechnological applications.

Alpha-Tocopherol-Infused Flexible Liposomal Nanocomposite Pressure-Sensitive Adhesive: Enhancing Skin Permeation of Retinaldehyde

Retinaldehyde (RAL), or retinal, is a vitamin A derivative that is widely used for several skin conditions. However, it is light sensitive and has low water solubility, limiting its efficiency in transdermal delivery. This study developed a novel delivery system for retinal (RAL) using flexible liposomes (FLPs) infused with α-tocopherol succinate (α-TS) to improve stability, and enhance skin permeability. The RAL-FLPs were embedded in pressure-sensitive adhesive (PSA) hydrogels, creating a delivery platform that supports prolonged skin residence and efficient permeation of RAL. The stability and skin permeation as well as human skin irritation and adhesion capabilities were assessed to determine the formulation's safety and efficacy. Our findings suggested that the addition of α-TS could improve liposomal stability and RAL chemical stability. Moreover, the skin permeation and fluorescence microscopic-based studies suggested that the addition of α-TS could enhance skin permeability of RAL through hair follicles. The RAL-FLP was embedded in PSA hydrogels fabricated from 25% GantrezTM S-97 (GT) and 1% hyaluronic acid (Hya) with aluminum as a crosslinker. The PSA hydrogel exhibited desirable peeling and tacking strengths. The developed hydrogels also demonstrated greater skin deposition of RAL compared with its aqueous formulation. Additionally, the RAL-FLP-embedded PSA hydrogels showed no skin irritation and maintained better adhesion for up to 24 h compared to commercial patches. Hence, the developed hydrogels could serve as a beneficial platform for delivering RAL in treating skin conditions.

Retinoic acid in Parkinson's disease: Molecular insights, therapeutic advances, and future prospects

Parkinson's disease (PD) is a common and progressively worsening neurodegenerative disorder characterized by abnormal protein homeostasis and the degeneration of dopaminergic neurons, particularly in the substantia nigra pars compacta. The prevalence of PD has doubled in the past 25 years, now affecting over 8.5 million individuals worldwide, underscoring the need for effective management strategies. While current pharmacological therapies provide symptom relief, they face challenges in treating advanced PD stages. Recent research highlights the therapeutic benefits of retinoic acid (RA) in PD, demonstrating its potential to mitigate neuroinflammation and oxidative stress, regulate brain aging, promote neuronal plasticity, and influence circadian rhythm gene expression and retinoid X receptor heterodimerization. Additionally, RA helps maintain intestinal homeostasis and modulates the enteric nervous system, presenting significant therapeutic potential for managing PD. This review explores RA as a promising alternative to conventional therapies by summarizing the molecular mechanisms underlying its role in PD pathophysiology and presenting up-to-date insights into both preclinical and clinical studies of RA in PD treatment. It also delves into cutting-edge formulations incorporating RA, highlighting ongoing efforts to refine therapeutic strategies by integrating RA into novel treatments. This comprehensive overview aims to advance progress in the field, contribute to the development of effective, targeted treatments for PD, and enhance patient well-being. Further research is essential to fully explore RA's therapeutic potential and validate its efficacy in PD treatment.

Topical retinoids: Novel derivatives, nano lipid-based carriers, and combinations to improve chemical instability and skin irritation

BACKGROUND

Retinoids, defined as synthetic or natural derivatives of vitamin A, have been extensively studied as anti-aging molecules that are widely applied in cosmetics. However, due to their physicochemical property, retinoids are highly unstable and extremely sensitive to light, oxygen, and temperature. Moreover, topical application of retinoids often leads to cutaneous irritation. These instabilities and irritant properties of retinoids limit their application in cosmetic and pharmaceutical products.

AIM

Our study aimed to provide a systematic review to summarize the mechanisms underlying the instability and irritant properties of retinoids, as well as recent developments in addressing these challenges.

METHODS

A comprehensive PubMed search was conducted using the following keywords: retinoids, chemical instability, skin irritation, retinoid derivatives, nano lipid-based carriers, liposomes, penetration-enhancer vesicles, ethosomes, niosomes, nanoemulsions, solid lipid nanoparticles, vitamins, soothing and hydrating agents, antioxidants and metal chelator and retinol combinations. Relevant researches published between 1968 and 2023 and studies related to these reports were reviewed.

RESULTS

The development of new retinoid derivatives, the utilization of new delivery systems like nano lipid-based carriers and the combination with other compounds like vitamins, soothing agents, antioxidants and metal chelator have been explored to improve the stability, bioavailability, and toxicity of the retinoid family.

CONCLUSIONS

Through advancements in formulation techniques, structure modification of retinoid derivatives and development of novel nano lipid-based carriers, the chemical instability and skin irritation of retinoids has been mitigated, ensuring their efficacy and potency over extended periods.

Momordica cochinchinensis extract alleviates oxidative stress and skin damage caused by fine particulate matter

Momordica cochinchinensis (MC), commonly known as gac fruit, is a tropical fruit rich in antioxidants and bioactive compounds. This research aimed to elucidate the effect of MC on apoptosis induced by fine particulate matter with a diameter of less than 10 μm (< PM10) in epidermal keratinocyte HaCaT cells. We found that PM10 significantly diminish the viability of HaCaT cells through cytotoxic mechanisms. However, the treatment with MC at a concentration of 10 μg/mL notably restored the cellular viability decreased by PM10. MC reduced the activation of extracellular signal-regulated kinase (ERK) and p38 mitogen-activated protein kinase (MAPK) by mainly preventing the generation of reactive oxygen species (ROS) in HaCaT cells subjected to PM10. Furthermore, MC exhibited a regulatory effect on the expression of genes associated with apoptosis, including B-Cell Lymphoma 2 (Bcl-2), Bcl-2 associated X protein (Bax), and cleaved caspase-3 by inhibiting the activation of the transcription factor nuclear factor-kappa B (NF-κB). These findings demonstrate that MC aids in neutralizing the apoptotic signaling pathway of free radicals produced by environmental pollutants such as PM10, which have the potential to damage skin cells and accelerate the aging process.

Solid Lipid Nanoparticles Incorporated with Retinol and Pentapeptide-18-Optimization, Characterization, and Cosmetic Application

Solid lipid nanoparticles (SLNs) incorporated with retinol and oligopeptide can have a full spectrum of effects on the skin as a compatible combination of ingredients with broad anti-aging properties. The research's main objective was to ensure the stability of lipid nanocarriers containing retinol and peptide due to the planned use of this dispersion as a cosmetic raw material. To confirm the effectiveness of method optimization (high shear homogenization, HSH) and proper selection of substrates, SLN dispersions were obtained in three combinations: 1-non-incorporated SLNs; 2-SLNs containing only retinol; 3-SLNs containing retinol and pentapeptide-18; these were then stored at different temperatures (4, 25, 45 °C) for 4 weeks. The desired values of the physicochemical parameters of the optimized dispersion of lipid nanoparticles incorporated with retinol and oligopeptide over the required storage period were confirmed: mean particle size (Z-Ave) = 134.7 ± 0.3 nm; polydispersity index (PDI) = 0.269 ± 0.017 [-]; zeta potential (ZP) = 42.7 ± 1.2 mV (after 4 weeks at 25 °C). The results confirmed the proper selection of the SLN production method and the effectiveness of the optimization performed. The possibility of using the obtained raw material as an ingredient in cosmetic products with anti-aging properties was indicated.

The Influence of Retinol Ointment on Rabbit Skin (Oryctolagus cuniculus) Ion Transport-An In Vitro Study

Retinoids are known to improve the condition of the skin. Transepithelial transport of sodium and chloride ions is important for proper skin function. So far, the effect of applying vitamin A preparations to the skin on ion transport has not been evaluated. In the study, electrophysiological parameters, including transepithelial electric potential (PD) and transepithelial resistance (R), of rabbit skin specimens after 24 h exposure to retinol ointment (800 mass units/g) were measured in a modified Ussing chamber. The R of the fragments incubated with retinol was significantly different than that of the control skin samples incubated in iso-osmotic Ringer solution. For the controls, the PD values were negative, whereas the retinol-treated specimens revealed positive PD values. Mechanical-chemical stimulation with the use of inhibitors of the transport of sodium (amiloride) or chloride (bumetanide) ions revealed specific changes in the maximal and minimal PD values measured for the retinol-treated samples. Retinol was shown to slightly modify the transport pathways of sodium and chloride ions. In particular, an intensification of the chloride ion secretion from keratinocytes was observed. The proposed action may contribute to deep hydration and increase skin tightness, limiting the action of other substances on its surface.

A Comprehensive Review of the Strategies to Reduce Retinoid-Induced Skin Irritation in Topical Formulation

Currently, retinoids are known for their abundant benefits to skin health, ranging from reducing signs of aging and decreasing hyperpigmentation to treating acne. However, it cannot be denied that there are various side effects associated with the use of retinoids on the skin, one of which is irritation. Several approaches can be employed to minimize the irritation caused by retinoids. This review article discusses topical retinoid formulation technology strategies to reduce skin irritation effects. The methodology used in this study is a literature review of 21 reference journals. The sources used in compiling this review are from PubMed, Scopus, ScienceDirect, and MEDLINE. The findings obtained indicate that the following methods can be used to lessen retinoid-induced irritation in topical formulations: developing drug delivery systems in the formulation, such as encapsulating retinoids, transforming retinoids into nanoparticles, forming complexes (e.g., with cyclodextrin), and binding retinoids with carriers (e.g., polymers, NLC, SLN), adding ingredients with anti-irritation activity, skin barrier improvement, and increased skin hydration to retinoid formulations (e.g., combinations of glucosamine, trehalose, ectoine, sucralfate, omega-9, and 4-t-butylcyclohexanol, addition of ethanolic bark extract of Alstonia scholaris R. Br).

Multilayered collagen-lipid hybrid nanovesicles for retinol stabilization and efficient skin delivery

Lipid-based nanocarriers have been extensively utilized for the solubilization and cutaneous delivery of water-insoluble active ingredients in skincare formulations. However, their practical application is often limited by structural instability, leading to premature release and degradation of actives. Here we present highly robust multilamellar nanovesicles, prepared by the polyionic self-assembly of unilamellar vesicles with hydrolyzed collagen peptides, to stabilize all-trans-retinol and enhance its cutaneous delivery. Our results reveal that the reinforced multilayer structure substantially enhances dispersion stability under extremely harsh conditions, like freeze-thaw cycles, and stabilizes the encapsulated retinol. Interestingly, these multilamellar vesicles exhibit significantly lower cytotoxicity to human dermal fibroblasts than their unilamellar counterparts, likely due to their smaller particle number per weight, minimizing potential disruptions to cellular membranes. In artificial skin models, retinol-loaded multilamellar vesicles effectively upregulate collagen-related gene expression while suppressing the synthesis of metalloproteinases. These findings suggest that the robust multilamellar vesicles can serve as effective nanocarriers for the efficient delivery and stabilization of bioactive compounds in cutaneous applications.

Retinoic acid breakdown is required for proximodistal positional identity during amphibian limb regeneration

Regenerating limbs retain their proximodistal (PD) positional identity following amputation. This positional identity is genetically encoded by PD patterning genes that instruct blastema cells to regenerate the appropriate PD limb segment. Retinoic acid (RA) is known to specify proximal limb identity, but how RA signaling levels are established in the blastema is unknown. Here, we show that RA breakdown via CYP26B1 is essential for determining RA signaling levels within blastemas. CYP26B1 inhibition molecularly reprograms distal blastemas into a more proximal identity, phenocopying the effects of administering excess RA. We identify Shox as an RA-responsive gene that is differentially expressed between proximally and distally amputated limbs. Ablation of Shox results in shortened limbs with proximal skeletal elements that fail to initiate endochondral ossification. These results suggest that PD positional identity is determined by RA degradation and RA-responsive genes that regulate PD skeletal element formation during limb regeneration.

RiboScreenTM Technology Delivers a Ribosomal Target and a Small-Molecule Ligand for Ribosome Editing to Boost the Production Levels of Tropoelastin, the Monomeric Unit of Elastin

Elastin, a key structural protein essential for the elasticity of the skin and elastogenic tissues, degrades with age. Replenishing elastin holds promise for anti-aging cosmetics and the supplementation of elastic activities of the cardiovascular system. We employed RiboScreenTM, a technology for identifying molecules that enhance the production of specific proteins, to target the production of tropoelastin. We make use of RiboScreenTM in two crucial steps: first, to pinpoint a target ribosomal protein (TRP), which acts as a switch to increase the production of the protein of interest (POI), and second, to identify small molecules that activate this ribosomal protein switch. Using RiboScreenTM, we identified ribosomal protein L40, henceforth eL40, as a TRP switch to boost tropoelastin production. Drug discovery identified a small-molecule hit that binds to eL40. In-cell treatment demonstrated activity of the eL40 ligand and delivered increased tropoelastin production levels in a dose-dependent manner. Thus, we demonstrate that RiboScreenTM can successfully identify a small-molecule hit capable of selectively enhancing tropoelastin production. This compound has the potential to be developed for topical or systemic applications to promote skin rejuvenation and to supplement elastic functionality within the cardiovascular system.

Functional foods lipids: unraveling their role in the immune response in obesity

Functional lipids are lipids that are found in food matrices and play an important role in influencing human health as their role goes beyond energy storage and structural components. Ongoing research into functional lipids has highlighted their potential to modulate immune responses and other mechanisms associated with obesity, along with its comorbidities. These lipids represent a new field that may offer new therapeutic and preventive strategies for these diseases by understanding their contribution to health. In this review, we discussed in-depth the potential food sources of functional lipids and their reported potential benefit of the major lipid classification: based on their composition such as simple, compound, and derived lipids, and based on their function such as storage and structural, by investigating the intricate mechanisms through which these lipids interact in the human body. We summarize the key insights into the bioaccessibility and bioavailability of the most studied functional lipids. Furthermore, we review the main immunomodulatory mechanisms reported in the literature in the past years. Finally, we discuss the perspectives and challenges faced in the food industry related to functional lipids.

Combined multilevel anti-aging strategies and practical applications of dermocosmetics in aesthetic procedures

Management of the signs of facial aging and other cosmetic skin problems have greatly evolved in the past years. People are also seeking to improve their well-being and global skin appearance, and when they consider using cosmetic procedures, they expect natural and long-lasting aesthetic results. Combined dermocosmetic approaches that address the signs of facial aging at all levels are increasingly being used by dermatologists to meet patient expectations while ensuring their safety. Minimally invasive and reversible procedures that can be performed in only one session are popular approaches for skin restructuring and volumizing as they are flexible, rapid and less burdensome for patients. These interventions can achieve even better outcomes when they are combined with cosmeceuticals as pre- or post-procedural adjuvants to prepare the skin, accelerate recovery and sustain results. The use of topical dermocosmetics is also recommended as part of the daily skin care routine to improve skin quality and help maintain skin barrier function. This review thus outlines the most commonly used combined multilevel anti-aging strategies, which start by addressing the deepest skin layers and then the more superficial signs of skin aging. Examples of multi-active cosmeceuticals and skin delivery enhancing systems are also presented, together with examples of the use of dermocosmetics as supportive care for aesthetic procedures, to provide insights into current applications of dermocosmetic products.

Photoaging and cosmeceutical solutions in sun-overexposed countries: The experience of Australia and Brazil

Skin aging is the result of physiological changes determined by genetically driven processes and intrinsic factors, and exacerbated by a combination of multiple environmental factors, the main one being sun exposure. The effects of photoaging are particularly apparent on the face, where the appearance of aging signs can have a significant impact on the emotions conveyed and well-being. Photoprotection and facial skin care for managing photoaging signs are thus of particular importance for both physical and mental health. Countries, like Australia and Brazil, where the level of sun exposure is high and the populations have predominantly outdoor lifestyles, are particularly aware of the harms of photoaging and have implemented several measures to help reduce the risk of skin cancer in their populations. However, sun-seeking behaviours are difficult to change, and it takes time before interventions provide perceptible results. Australia still has some of the highest skin cancer incidence and mortality rates in the world. Solutions that target individuals can also be used for minimizing the clinical signs of facial aging and for improving skin quality, with the ultimate aim being not only to improve the appearance of the skin but also to mitigate the occurrence of pre-malignant and malignant lesions. This review summarizes the features of facial skin photoaging in photo-exposed populations, based on evidence gained from studies of Australian individuals, and discusses the various available solutions for skin photoaging, in particular those that are most popular in Brazil, which is a country with many years of experience in managing photoaged skin.

Spectral and mass characterization of kinetic conversion from retinoids to retinoic acid in an in vitro 3-D human skin equivalent model

To investigate the effect of retinoids, such as retinol (ROL), retinal (RAL), and retinyl palmitate (RP), on epidermal integrity, skin deposition, and bioconversion to retinoic acid (RA). 3-D human skin equivalent model (EpiDermFT™) was used. Epidermal cellular integrity measured by TEER values was significantly higher for a topical treatment of ROL and RAL than RP (p < 0.05). The skin deposition (μM) of ROL and RAL was approximately 269.54 ± 73.94 and 211.35 ± 20.96, respectively, greater than that of RP (63.70 ± 37.97) over 2 h incubation. Spectral changes were revealed that the CO maximum absorbance occurred between 1600∼1800 cm-1 and was greater from ROL than that from RAL and RP, indicating conjugation of R-OH to R-CHO or R-COOH could strongly occur after ROL treatment. Subsequently, a metabolite from the bioconversion of ROL and RAL was identified as RA, which has a product ion of m/z 283.06, by using liquid a chromatography-mass spectrometry (LC-MS) - total ion chromatogram (TIC). The amount of bioconversion from ROL and RAL to RA in artificial skin was 0.68 ± 0.13 and 0.70 ± 0.10 μM at 2 h and 0.60 ± 0.04 and 0.57 ± 0.06 μM at 24 h, respectively. RA was not detected in the skin and the receiver compartment after RP treatment. ROL could be a useful dermatological ingredient to maintain epidermal integrity more effectively, more stably deposit on the skin, and more steadily metabolize to RA than other retinoids such as RAL and RP.

The quantum mechanics of skincare: A context for the biochemistry curriculum

Designing a relevant and engaging curriculum for biochemistry undergraduates can be challenging for topics which are at the periphery of the subject. We have used the framework of context-based learning as a means of assessing understanding of quantum theory in a group of students in their junior year. Our context, the role of retinol in skincare, provides a basis for the simple application of quantum mechanical principles to a biological context in an adaptation of the polyene in a box concept. As part of the learner journey, they gain experience of practical computational chemistry, which provided an in silico alternative to traditional laboratory work during the SARS-CoV-19 pandemic. Student feedback was overwhelmingly positive, and this approach is now firmly embedded in the undergraduate curriculum.

Top weapons in skin aging and actives to target the consequences of skin cell senescence

Skin aging has long been considered a purely cosmetic problem. However, as life expectancy increases, skin aging is taking on a functional dimension that goes beyond cosmetics and appearance. Preventive or therapeutic strategies are needed to target cellular senescence, a key process underlying the alterations in skin function and appearance that occur with aging, as well as to address the age-related skin changes associated with 'dermatoporosis' and chronic skin insufficiency/fragility syndrome. Thus, given the need for effective anti-aging products that improve both the appearance and function of the skin, it is essential to distinguish active ingredients that have been proven to be effective, among the large number of available over-the-counter cosmeceuticals. This brief review focuses on a core group of topical actives, describing their clinical effects on senescence and aging, and their molecular mechanisms of action. These actives include hyaluronic acid, which has hydrating and viscoelastic properties and has been shown to reduce skin atrophy; retinaldehyde, which activates retinoid receptors and increases cutaneous elasticity; vitamins C and E, which provide stable oxidative protection; and niacinamide, which reduces inflammation and mitigates the effects of senescence.

Cyclodextrins and Amino Acids Enhance Solubility and Tolerability of Retinoic Acid/Tretinoin: Molecular Docking, Physicochemical, Cytotoxicity, Scratch Assay, and Topical Gel Formulations Investigation

With increasing longevity globally, the search for effective and patient-friendly anti-aging solutions has been growing. Retinoic acid (Ret) is an FDA-approved anti-aging and anti-wrinkling formula, however, its poor solubility and poor tolerability hamper its use in cosmetically accepted formulations. In this study, cyclodextrins and arginine were investigated for improving the solubility and tolerability of retinoic acid through the formation of inclusion complexes and salt formation, respectively. Two different methods were employed: physical mixing and kneading. The prepared dispersions were investigated for molecular docking (MD), solubility, thermal and spectral analyses, cytotoxicity, and scratch assays. The optimized disperse systems were formulated in a gel formulation and characterized for rheological, in vitro release, and kinetics. The MD, DSC, and FTIR results indicated that both β- and hydroxy propyl (HP) β-cyclodextrins could host RA in their cavities and form inclusion complexes. Ret can form a salt with the basic amino acid arginine. Solubility studies of RA significantly (p < 0.01) enhanced by 14- to 81-fold increases with the investigated cyclodextrins and arginine. The cell viability recorded for Ret:HP β-CD K and Ret:arginine K was significantly increased compared to that for Ret alone. The IC50% recorded for azelaic acid (mild to non-irritant control), Ret, Ret:HP β-CD K, and Ret:arginine K were 1000, 485, 1100, and 895 µg/mL, respectively. The two carriers (HP β-CD and the amino acid arginine) were able to significantly (p < 0.05) reduce the irritation potential of Ret. Furthermore, comparable gap closure rates were recorded for Ret alone, Ret:HP β-CD K, and Ret:arginine K, indicating that inclusion complexation and ion pair formation reduced the irritation potentials without undermining the efficacy.

Stackable Medical-Grade Skincare for the Cosmetic Medicine Patient: A Long-Term Pilot Assessment

Background

Multiple intrinsic and extrinsic factors influence aging and lead to visible changes in the skin, including dryness, fine lines and wrinkles, loss of elasticity, surface roughness, uneven pigmentation, and loss of luminosity. Although it is well established that a single combination of topicals can address multiple signs of skin aging, it is common for patients' at-home skin treatment routines to include multiple different topicals with different active ingredients. The layering of active ingredients can cause skin irritation, and lead to noncompliance with a consistent routine. Further, multiple active ingredients may exacerbate irritation from in-office aesthetic treatments.

Objectives

To assess the long-term efficacy, safety, tolerability, and patient adherence to a Stackable Treatment topical routine consisting of 4 complementary topical formulations.

Methods

This study examined a daily topical routine (Stackable Treatment routine) consisting of 4 topical formulas with different active ingredients, and evaluated the routine's safety, tolerability, and efficacy in a composite of in-office treatment patients who applied the routine for a minimum of 1 year.

Results

Of the 14 patients, 0 experienced adverse reactions. Improvements to multiple skin parameters were observed, including improvements to skin hydration, surface texture, pigmentation, vasculature, and the appearance of scars. The majority of patients continue to use the Stackable Treatment routine after the study's conclusion.

Conclusions

The combination of low incidence of irritation, high patient satisfaction, and overall efficacy of the routine indicates the Stackable Treatment routine may be well suited as a foundational skin care regimen that can complement in-office aesthetic treatments.

Level of Evidence 4

Melasma: A Step-by-Step Approach Towards a Multimodal Combination Therapy

Melasma is a common challenge in the field of pigmentary skin disorders, exerting a significant emotional and psychosocial burden on patients. The persistent and recurring nature of melasma complicates its management in routine clinical practice. This comprehensive review outlines a stepwise, practical approach encompassing diagnostic, preventive and therapeutic strategies for the management of melasma. A thorough exploration of aggravating and exacerbating factors, including sun exposure, hormonal imbalances, photosensitizing medication and cosmetics, is essential for a holistic assessment of the disease. With an emphasis on consistent and effective photoprotection, initial topical treatment modalities target the melanin production and/or the transfer of melanosomes to keratinocytes. Topical tyrosine inhibitors emerge as the first choice for reducing and preventing hyperpigmentation, with compounds such as thiamidol or tranexamic acid (TXA) being preferred for their safety profile over hydroquinone (HQ), kojic acid and arbutin. Combination with chemical peels can further enhance the therapeutic efficacy, even in cases with resistant melasma. In more severe cases, laser- and light-based interventions may be considered, but with the caveat of the likelihood of recurrence within 3-6 months. Assisted TXA delivery, via either fractional non-ablative laser or microneedling techniques, can further improve clinical outcomes. In conclusion, an optimal melasma management strategy is a multimodal approach, which includes effective photoprotection and a mix of different topical treatments targeting melanin synthesis, the anti-inflammatory environment, senescence and vascularity. Complementary procedures, such as chemical peels, and laser, light-based or microneedling procedures, with or without TXA, can further expedite melanin clearance in more severely affected instances. Individual discussions with patients regarding treatment expectations, recurrence likelihood and potential side effects are paramount to a comprehensive and successful therapeutic journey.

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.

Exploring Acne Treatments: From Pathophysiological Mechanisms to Emerging Therapies

Acne vulgaris is a common dermatological condition that can present across different ages but predominantly affects adolescents and young adults. Characterized by various lesion types, the pathogenesis of acne is complex, involving genetic, hormonal, microbial, and inflammatory factors. This review comprehensively addresses current and emerging acne management strategies, emphasizing both topical and systemic treatments, procedural therapies, and dietary modifications. Key topical agents include retinoids, benzoyl peroxide, antibiotics, and other specialized compounds. Systemic options like antibiotics, hormonal therapies, and retinoids offer significant therapeutic benefits, particularly for moderate to severe cases. Procedural treatments such as laser devices, photodynamic therapy, chemical peels, and intralesional injections present viable alternatives for reducing acne symptoms and scarring. Emerging therapies focus on novel biologics, bacteriophages, probiotics, and peptides, providing promising future options. This review underscores the importance of personalized approaches to treatment due to the multifaceted nature of acne, highlighting the potential of innovative therapies for improving patient outcomes.

Integrative bioinformatics and experimental validation of hub genetic markers in acne vulgaris: Toward personalized diagnostic and therapeutic strategies

BACKGROUND

Acne vulgaris is a widespread chronic inflammatory dermatological condition. The precise molecular and genetic mechanisms of its pathogenesis remain incompletely understood. This research synthesizes existing databases, targeting a comprehensive exploration of core genetic markers.

METHODS

Gene expression datasets (GSE6475, GSE108110, and GSE53795) were retrieved from the GEO. Differentially expressed genes (DEGs) were identified using the limma package. Enrichment analyses were conducted using GSVA for pathway assessment and clusterProfiler for GO and KEGG analyses. PPI networks and immune cell infiltration were analyzed using the STRING database and ssGSEA, respectively. We investigated the correlation between hub gene biomarkers and immune cell infiltration using Spearman's rank analysis. ROC curve analysis validated the hub genes' diagnostic accuracy. miRNet, TarBase v8.0, and ChEA3 identified miRNA/transcription factor-gene interactions, while DrugBank delineated drug-gene interactions. Experiments utilized HaCaT cells stimulated with Propionibacterium acnes, treated with retinoic acid and methotrexate, and evaluated using RT-qPCR, ELISA, western blot, lentiviral transduction, CCK-8, wound-healing, and transwell assays.

RESULTS

There were 104 genes with consistent differences across the three datasets of paired acne and normal skin. Functional analyses emphasized the significant enrichment of these DEGs in immune-related pathways. PPI network analysis pinpointed hub genes PTPRC, CXCL8, ITGB2, and MMP9 as central players in acne pathogenesis. Elevated levels of specific immune cell infiltration in acne lesions corroborated the inflammatory nature of the disease. ROC curve analysis identified the acne diagnostic potential of four hub genes. Key miRNAs, particularly hsa-mir-124-3p, and central transcription factors like TFEC were noted as significant regulators. In vitro validation using HaCaT cells confirmed the upregulation of hub genes following Propionibacterium acnes exposure, while CXCL8 knockdown reduced pro-inflammatory cytokines, cell proliferation, and migration. DrugBank insights led to the exploration of retinoic acid and methotrexate, both of which mitigated gene expression upsurge and inflammatory mediator secretion.

CONCLUSION

This comprehensive study elucidated pivotal genes associated with acne pathogenesis, notably PTPRC, CXCL8, ITGB2, and MMP9. The findings underscore potential biomarkers, therapeutic targets, and the therapeutic potential of agents like retinoic acid and methotrexate. The congruence between bioinformatics and experimental validations suggests promising avenues for personalized acne treatments.

Unveiling the Nuances of Adult Female Acne: A Comprehensive Exploration of Epidemiology, Treatment Modalities, Dermocosmetics, and the Menopausal Influence

Previously considered a skin disease exclusively affecting adolescents, characterized by inflammatory and non-inflammatory skin lesions, acne vulgaris is now increasingly observed in adult life, including post-menopause. Today, adult female acne (AFA) is a common chronic inflammatory disease of the pilosebaceous unit, with polymorphic lesions presenting as open or closed comedones, papules, pustules, and even nodules or cysts, often with the presence of sequelae. AFA may persist from adolescence or manifest de novo in adulthood. Its etiology is multifactorial, involving genetic, hormonal, dietary, and environmental factors, yet still incompletely understood. Increased sebum production, keratinocyte hyper-proliferation, inflammation, and reduced diversity of Cutibacterium acnes strains are the underlying disease mechanisms. During menopausal transition, a relative increase in androgen levels occurs, just as estrogens begin to decline, which can manifest itself as acne. Whereas most AFA exhibit few acne lesions with normo-androgenic serum levels, baseline investigations including androgen testing panel enable associated comorbidities to be eliminated, such as polycystic ovarian syndrome, congenital adrenal hyperplasia, or tumors. Another interesting feature is AFA's impact on quality of life, which is greater than in adolescents, being similar to other chronic diseases like asthma. The therapeutic approach to AFA depends on its severity and associated features. This review investigates the intricate facets of AFA, with a specific focus on incidence rates, treatment modalities, and the curious impact of menopause. Utilizing insights from contemporary literature and scientific discussions, this article seeks to advance our understanding of AFA, offering new perspectives to shape clinical practices and improve patient outcomes.

Comparative whole genome analysis of face-derived Streptococcus infantis CX-4 unravels the functions related to skin barrier

BACKGROUND

The skin microbiome is essential in guarding against harmful pathogens and responding to environmental changes by generating substances useful in the cosmetic and pharmaceutical industries. Among these microorganisms, Streptococcus is a bacterial species identified in various isolation sources. In 2021, a strain of Streptococcus infantis, CX-4, was identified from facial skin and found to be linked to skin structure and elasticity. As the skin-derived strain differs from other S. infantis strains, which are usually of oral origin, it emphasizes the significance of bacterial variation by the environment.

OBJECTIVE

This study aims to explore the unique characteristics of the CX-4 compared to seven oral-derived Streptococcus strains based on the Whole-Genome Sequencing data, focusing on its potential role in skin health and its possible application in cosmetic strategies.

METHODS

The genome of the CX-4 strain was constructed using PacBio Sequencing, with the assembly performed using the SMRT protocol. Comparative whole-genome analysis was then performed with seven closely related strains, utilizing web-based tools like PATRIC, OrthoVenn3, and EggNOG-mapper, for various analyses, including protein association analysis using STRING.

RESULTS

Our analysis unveiled a substantial number of Clusters of Orthologous Groups in diverse functional categories in CX-4, among which sphingosine kinase (SphK) emerged as a unique product, exclusively present in the CX-4 strain. SphK is a critical enzyme in the sphingolipid metabolic pathway, generating sphingosine-1-phosphate. The study also brought potential associations with isoprene formation and retinoic acid synthesis, the latter being a metabolite of vitamin A, renowned for its crucial function in promoting skin cell growth, differentiation, and maintaining of skin barrier integrity. These findings collectively suggest the potential of the CX-4 strain in enhancing of skin barrier functionality.

CONCLUSION

Our research underscores the potential of the skin-derived S. infantis CX-4 strain by revealing unique bacterial compounds and their potential roles on human skin.

Nanocosmeceuticals: Trends and Recent Advancements in Self Care

The term cosmetics refers to any substances or products intended for external application on the skin with the aim of protection and better appearance of the skin surface. The skin delivery system promotes the controlled and targeted delivery of active ingredients. The development of this system has been driven by challenges encountered with conventional cosmeceuticals, including low skin retention of active components, limited percutaneous penetration, poor water dispersion of insoluble active ingredients, and instability of effective components. The aim is to create cosmeceuticals that can effectively overcome these issues. This review focuses on various nanocarriers used in cosmeceuticals currently and their applications in skin care, hair care, oral care, and more. The importance of nanotechnology in the sphere of research and development is growing. It provides solutions to various problems faced by conventional technologies, methods, and product formulations thus taking hold of the cosmetic industry as well. Nowadays, consumers are investing in cosmetics only for better appearance thus problems like wrinkles, ageing, hair loss, and dandruff requires to be answered proficiently. Nanocarriers not only enhance the efficacy of cosmeceutical products, providing better and longer-lasting effects, but they also contribute to the improved aesthetic appearance of the products. This dual benefit not only enhances the final quality and efficacy of the product but also increases consumer satisfaction. Additionally, nanocarriers offer protection against UV rays, further adding to the overall benefits of the cosmeceutical product. Figure 1 represents various advantages of nanocarriers used in cosmeceuticals. Nanotechnology is also gaining importance due to their high penetration of actives in the deeper layers of skin. It can be said that nanotechnology is taking over all the drawbacks of the traditional products. Thus, nanocarriers discussed in this review are used in nanotechnology to deliver the active ingredient of the cosmeceutical product to the desired site.

Kick-Starting Wound Healing: A Review of Pro-Healing Drugs

Cutaneous wound healing consists of four stages: hemostasis, inflammation, proliferation/repair, and remodeling. While healthy wounds normally heal in four to six weeks, a variety of underlying medical conditions can impair the progression through the stages of wound healing, resulting in the development of chronic, non-healing wounds. Great progress has been made in developing wound dressings and improving surgical techniques, yet challenges remain in finding effective therapeutics that directly promote healing. This review examines the current understanding of the pro-healing effects of targeted pharmaceuticals, re-purposed drugs, natural products, and cell-based therapies on the various cell types present in normal and chronic wounds. Overall, despite several promising studies, there remains only one therapeutic approved by the United States Food and Drug Administration (FDA), Becaplermin, shown to significantly improve wound closure in the clinic. This highlights the need for new approaches aimed at understanding and targeting the underlying mechanisms impeding wound closure and moving the field from the management of chronic wounds towards resolving wounds.

Rationalizing a prospective coupling effect of cannabinoids with the current pharmacotherapy for melanoma treatment

Melanoma is one of the leading fatal forms of cancer, yet from a treatment perspective, we have minimal control over its reoccurrence and resistance to current pharmacotherapies. The endocannabinoid system (ECS) has recently been accepted as a multifaceted homeostatic regulator, influencing various physiological processes across different biological compartments, including the skin. This review presents an overview of the pathophysiology of melanoma, current pharmacotherapy used for treatment, and the challenges associated with the different pharmacological approaches. Furthermore, it highlights the utility of cannabinoids as an additive remedy for melanoma by restoring the balance between downregulated immunomodulatory pathways and elevated inflammatory cytokines during chronic skin conditions as one of the suggested critical approaches in treating this immunogenic tumor. This article is categorized under: Cancer > Molecular and Cellular Physiology.

Exploring the potential of the nano-based sunscreens and antioxidants for preventing and treating skin photoaging

Excessive exposure to sunlight, especially UV irradiation, causes skin photodamage. Sunscreens, such as TiO2 and ZnO, can potentially prevent UV via scattering, reflection, and absorption. Topical antioxidants are another means of skin photoprotection. Developing nanoparticles for sunscreens and antioxidants is recommended for photoaging prevention and treatment as it can improve uncomfortable skin appearance, stability, penetration, and safety. This study reviewed the effects of nano-sized sunscreens and antioxidants on skin photoprevention by examining published studies and articles from PubMed, Scopus, and Google Scholar, which explore the topics of skin photoaging, skin senescence, UV radiation, keratinocyte, dermal fibroblast, sunscreen, antioxidant, and nanoparticle. The researchers of this study also summarized the nano-based UV filters and therapeutics for mitigating skin photoaging. The skin photodamage mechanisms are presented, followed by the introduction of current skin photoaging treatment. The different nanoparticle types used for topical delivery were also explored in this study. This is followed by the mechanisms of how nanoparticles improve the UV filters and antioxidant performance. Lastly, recent investigations were reviewed on nanoparticulate sunscreens and antioxidants in skin photoaging management. Sunscreens and antioxidants for topical application have different concepts. Topical antioxidants are ideal for permeating into the skin to exhibit free radical scavenging activity, while UV filters are prescribed to remain on the skin surface without absorption to exert the UV-blocking effect without causing toxicity. The nanoparticle design strategy for meeting the different needs of sunscreens and antioxidants is also explored in this study. Although the benefits of using nanoparticles for alleviating photodamage are well-established, more animal-based and clinical studies are necessary.

In vitro and in vivo efficacy of a cosmetic product formulated with new lipid particles for the treatment of aged skin

BACKGROUND

The cumulative oxidative damage causes an acceleration in the skin aging.

OBJECTIVES

To evaluate the ability of a new patented matrix of lipid particles (SIREN CAPSULE TECHNOLOGY™) to have superior anti-aging properties due to its high sensitivity to reactive oxygen species (ROS), testing its efficacy versus free or encapsulated vitamins.

METHODS

An in vitro study was conducted to evaluate the protective effects of lipid particles using menadione as an enhancer of oxidative stress. Subsequently, in vivo studies evaluated skin hydration, skin barrier function, and smoothness and wrinkle depth. For this purpose, gels containing free or encapsulated vitamins were used as controls.

RESULTS

In vitro, the SIREN CAPSULE TECHNOLOGY™ gel shows inhibitory activity against ROS production through menadione induction. In fact, at both tested concentrations, ROS production is lower than in the control samples (placebo, free vitamins, encapsulated vitamins). In vivo, the net effect of SIREN CAPSULE TECHNOLOGY™ gel versus the others permitted to conclude that lipid particles exert a higher skin moisturizing effect (20.17%) and a stronger effect in reducing transepidermal water loss (-16.29%) after 4 weeks of treatment. As for surface analysis, a gel based on SIREN CAPSULE TECHNOLOGY™ improves the skin texture in a similar way than gel containing encapsulated vitamins (Ra and Rz variations in 4 weeks).

CONCLUSIONS

SIREN CAPSULE TECHNOLOGY™ represents an advance and a successful strategy to develop cosmetic products for the treatment of skin conditions associated with an accumulation of ROS. SIREN CAPSULE TECHNOLOGY™ represents a result-oriented breakthrough in the effective delivery of active ingredients to the skin.

Targeting breast cancer stem cells through retinoids: A new hope for treatment

Breast cancer is a complex and diverse disease accounting for nearly 30% of all cancers diagnosed in females. But unfortunately, patients develop resistance to the existing chemotherapeutic regimen, resulting in approximately 90% treatment failure. With over half a million deaths annually, it is imperative to explore new therapeutic approaches to combat the disease. Within a breast tumor, a small sub-population of heterogeneous cells, with a unique ability of self-renew and differentiation and responsible for tumor formation, initiation, and recurrence are referred to as breast cancer stem cells (BCSCs). These BCSCs have been identified as one of the main contributors to chemoresistance in breast cancer, making them an attractive target for developing novel therapeutic strategies. These cells exhibit surface biomarkers such as CD44+, CD24-/LOW, ALDH, CD133, and CD49f phenotypes. Higher expression of CD44+ and ALDH activity has been associated with the formation of tumors in various cancers. Moreover, the abnormal regulation of signaling pathways, including Hedgehog, Notch, β-catenin, JAK/STAT, and P13K/AKT/mTOR, leads to the formation of cancer stem cells, resulting in the development of tumors. The growing drug resistance in BC is a significant challenge, highlighting the need for new therapeutic strategies to combat this dreadful disease. Retinoids, a large group of synthetic derivatives of vitamin A, have been studied as chemopreventive agents in clinical trials and have been shown to regulate various crucial biological functions including vision, development, inflammation, and metabolism. On a cellular level, the retinoid activity has been well characterized and translated and is known to induce differentiation and apoptosis, which play important roles in the outcome of the transformation of tissues into malignant. Retinoids have been investigated extensively for their use in the treatment and prevention of cancer due to their high receptor-binding affinity to directly modulate gene expression programs. Therefore, in this study, we aim to summarize the current understanding of BCSCs, their biomarkers, and the associated signaling pathways. Retinoids, such as Adapalene, a third-generation retinoid, have shown promising anti-cancer potential and may serve as therapeutic agents to target BCSCs.

Beyond the Bottle: Exploring Health-Promoting Compounds in Wine and Wine-Related Products-Extraction, Detection, Quantification, Aroma Properties, and Terroir Effects

Health-promoting compounds in wine and wine-related products are important due to their potential benefits to human health. Through an extensive literature review, this study explores the presence of these compounds in wine and wine-related products, examining their relationship with terroir and their impact on the aromatic and flavor properties that are perceived orally: sunlight exposure, rainfall patterns, and soil composition impact grapevines' synthesis and accumulation of health-promoting compounds. Enzymes, pH, and the oral microbiome are crucial in sensory evaluation and perception of health promotion. Moreover, their analysis of health-promoting compounds in wine and wine-related products relies on considerations such as the specific target compound, selectivity, sensitivity, and the complexity of the matrix.

Porokeratoses-A Comprehensive Review on the Genetics and Metabolomics, Imaging Methods and Management of Common Clinical Variants

Porokeratosis is a heterogeneous group of keratinising disorders characterised by the presence of particular microscopic structural changes, namely the presence of the cornoid lamella. This structure develops as a consequence of a defective isoprenoid pathway, critical for cholesterol synthesis. Commonly recognised variants include disseminated superficial actinic porokeratosis, disseminated superficial porokeratosis, porokeratosis of Mibelli, palmoplantar porokeratosis (including porokeratosis palmaris et plantaris disseminata and punctate porokeratosis), linear porokeratosis, verrucous porokeratosis (also known as genitogluteal porokeratosis), follicular porokeratosis and porokeratoma. Apart from the clinical presentation and epidemiology of each variant listed, this review aims at providing up-to-date information on the precise genetic background, introduces imaging methods facilitating the diagnosis (conventional and ultraviolet-induced fluorescence dermatoscopy, reflectance confocal microscopy and pathology), discusses their oncogenic potential and reviews the literature data on the efficacy of the treatment used, including the drugs directly targeting the isoprenoid-mevalonate pathway.

Successful treatment of rare adverse event after radiofrequency microneedle on Fitzpatrick skin type IV : a case report

Radiofrequency microneedle (RFM) is relatively safe to use for all skin types but there is still possibility of adverse events. Tram-track scarring or uniform papular eruptions is a rarely reported adverse event, but it is challenging to manage. We report a case of successful treatment of tram track scarring post RFM using a combination of light emitting diodes 640 nm and a salicylic acid peel and home treatment with a combination of azelaic acid and retinoic acid. There is still no standard therapy to treat this case. The results of clinical observations showed the lesions completely recovered in 6 months.

Human Skin Aging and the Anti-Aging Properties of Retinol

The skin is the most-extensive and -abundant tissue in the human body. Like many organs, as we age, human skin experiences gradual atrophy in both the epidermis and dermis. This can be primarily attributed to the diminishing population of epidermal stem cells and the reduction in collagen, which is the primary structural protein in the human body. The alterations occurring in the epidermis and dermis due to the aging process result in disruptions to the structure and functionality of the skin. This creates a microenvironment conducive to age-related skin conditions such as a compromised skin barrier, slowed wound healing, and the onset of skin cancer. This review emphasizes the recent molecular discoveries related to skin aging and evaluates preventive approaches, such as the use of topical retinoids. Topical retinoids have demonstrated promise in enhancing skin texture, diminishing fine lines, and augmenting the thickness of both the epidermal and dermal layers.

Skin ageing and topical rejuvenation strategies

Skin ageing is a complex process involving the additive effects of skin's interaction with its external environment, predominantly chronic sun exposure, upon a background of time-dependent intrinsic ageing. Skin health and beauty is considered one of the principal factors perceived to represent overall 'health and wellbeing'; thus, the demand for skin rejuvenation strategies has rapidly increased, with a worldwide annual expenditure expected to grow from $US24.6 billion to around $US44.5 billion by 2030 (https://www.databridgemarketresearch.com/reports/global-facial-rejuvenation-market). Skin rejuvenation can be achieved in several ways, ranging from laser and device-based treatments to chemical peels and injectables; however, topical skin care regimes are a mainstay treatment for ageing skin and all patients seeking skin rejuvenation can benefit from this relatively low-risk intervention. While the most efficacious topical rejuvenation treatment is application of tretinoin (all-trans retinoic acid) - a prescription-only medicine considered to be the clinical 'gold standard' - a hybrid category of 'cosmeceutical' products at the midpoint of the spectrum of cosmetics and pharmaceutical has emerged. This article reviews the clinical manifestations of skin ageing and the available topical treatments for skin rejuvenation, including retinoids, peptides and antioxidants.

Antioxidant Skincare Treatment for Hyperpigmented and Photodamaged Skin: Multi-Center, Open-Label, Cross-Seasonal Case Study

Objective

The objective of this study is three-fold. Firstly, to evaluate an enhanced vitamin C serum (eVCS) and its' combination with a retinol-bakuchiol serum (RBS) on pigmentation in vitro. Secondly, to evaluate the effect of the eVCS on skin function ex vivo. Lastly, to evaluate eVCS and RSB in the treatment of facial hyperpigmentation and overall photodamage across a range of opposing environments.

Methods

MelanoDerm™ tissues were topically treated with the eVCS, and a eVCS and RSB blend for 14 days, and then a melanin assay was performed. Surgical waste facial skin explants were incubated with the eVCS or control for five days and then fixed and stained for skin physiology and structure. A 12-week, IRB approved, study on female subjects (n=29, aged 35 to 65) with moderate global facial hyperpigmentation and overall photodamage was completed. Clinical assessment, tolerability measurements, and subject-assessments were performed baseline at Weeks 6, 8, and 12. Investigator Global Aesthetic Improvement Score was completed at Week 12.

Results

The eVCS-treated facial skin explants achieved a significant 145 percent collagen increase compared to control. The eVCS-RSB combination proved synergistic in reducing melanin compared to the eVCS alone. The eVCS-RSB combination demonstrated significant clinical improvement at all timepoints and was well tolerated. Subject responses were favorable and GAIS score of 3.0 was achieved at Week 12, indicating an improvement.

Limitations

Limitations include lack of placebo or vehicle control.

Conclusion

The product pairing, eVCS and RSB, offers patients an efficacious and well-tolerated treatment to target pigmentation and photodamage.

Clinical Trial

This study, Pro00050557, was approved by Advarra IRB (Columbia, Maryland) and submitted to ClinicalTrials.gov #: NCT05423873.