Preparation, characterizations and anti-pollutant activity of 7,3',4'-trihydroxyisoflavone nanoparticles in particulate matter-induced HaCaT keratinocytes

Air Pollution and Skin Diseases

Air pollution is a widespread environmental issue, with substantial global implications for human health. Recent epidemiological studies have shown that exposure to air pollution exacerbates various inflammatory skin conditions, including atopic dermatitis, psoriasis, or acne. Furthermore, air pollutants are associated with accelerated skin aging, hair loss, and skin cancer. The aim of this review is to elucidate the current understanding of the impact of air pollution on skin health, emphasizing the underlying mechanisms involved and existing therapeutic and cosmetic interventions available to prevent or mitigate these effects. A pivotal factor in the harmful effects of air pollution is the formation of reactive oxygen species and the resulting oxidative stress. The aryl hydrocarbon receptor signaling pathway also substantially contributes to mediating the effects of air pollutants on various skin conditions. Moreover, air pollutants can disrupt the skin barrier function and trigger inflammation. Consequently, antioxidant and anti-inflammatory therapies, along with treatments designed to restore the skin barrier function, have the potential to mitigate the adverse effects of air pollutants on skin health.

Screening potential anti-osteoarthritis compounds using molecular docking based on MAPK and NFκB pathways and validating their anti-osteoarthritis effect

Osteoarthritis is an extremely common disease. However, it lacks effective nonsurgical treatments. Molecular docking has been widely used in drug discovery. However, no studies focus on screening anti-osteoarthritis compounds using molecular docking. This study aimed to screen potential anti-osteoarthritis compounds using molecular docking and validate their anti-osteoarthritis effect. Molecular dockings between 51 compounds inhibiting the MAPK and NFκB pathways but have not been used to treat osteoarthritis and 5 core human proteins in the MAPK and NFκB pathways were performed. Corilagin, Apigetrin, Protopine, 5-methoxyflavone, and 7,3',4'-trihydroxyisoflavone were selected. The drug-likeness, pharmacokinetics, bioactivity, and toxicity of the selected compounds were analyzed. The cytotoxicity and anti-osteoarthritis effect of the selected compounds were tested on mouse chondrocytes. This study found that molecular docking based on the MAPK and NFκB pathways can be used to screen potential anti-osteoarthritis compounds, providing a perspective on drug discovery through pathway-based screening. ERK2, JNK2, and p38 showed similar binding sites commonly interacting with the compounds. The theoretical drug-likeness, pharmacokinetics, bioactivity, and toxicity were largely consistent with the empirical cytotoxicity and anti-osteoarthritis effect. Additionally, Protopine, 5-methoxyflavone, and 7,3',4'-trihydroxyisoflavone showed strong anti-osteoarthritis potential and can be considered for future studies to test their anti-osteoarthritis effect in animal models, explore molecular mechanisms, and improve their solubility.

Therapeutic Potential of Herbal Medicines in Combating Particulate Matter (PM)-Induced Health Effects: Insights from Recent Studies

Particulate matter (PM), particularly fine (PM2.5) and ultrafine (PM0.1) particles, originates from both natural and anthropogenic sources, such as biomass burning and vehicle emissions. These particles contain harmful compounds that pose significant health risks. Upon inhalation, ingestion, or dermal contact, PM can penetrate biological systems, inducing oxidative stress, inflammation, and DNA damage, which contribute to a range of health complications. This review comprehensively examines the protective potential of natural products against PM-induced health issues across various physiological systems, including the respiratory, cardiovascular, skin, neurological, gastrointestinal, and ocular systems. It provides valuable insights into the health risks associated with PM exposure and highlights the therapeutic promise of herbal medicines by focusing on the natural products that have demonstrated protective properties in both in vitro and in vivo PM2.5-induced models. Numerous herbal medicines and phytochemicals have shown efficacy in mitigating PM-induced cellular damage through their ability to counteract oxidative stress, suppress pro-inflammatory responses, and enhance cellular defense mechanisms. These combined actions collectively protect tissues from PM-related damage and dysfunction. This review establishes a foundation for future research and the development of effective interventions to combat PM-related health issues. However, further studies, including in vivo and clinical trials, are essential to evaluate the safety, optimal dosages, and long-term effectiveness of herbal treatments for patients under chronic PM exposure.

Anti-cancer activity and cellular uptake of 7,3',4'- and 7,8,4'-trihydroxyisoflavone in HepG2 cells under hypoxic conditions

Transarterial chemoembolisation (TACE) is used for unresectable hepatocellular carcinoma (HCC) treatment, but TACE-induced hypoxia leads to poor prognosis. The anti-cancer effects of soybean isoflavones daidzein derivatives 7,3',4'-trihydroxyisoflavone (734THIF) and 7,8,4'-trihydroxyisoflavone (784THIF) were evaluated under hypoxic microenvironments. Molecular docking of these isomers with cyclooxygenase-2 (COX-2) and vascular endothelial growth factor receptor 2 (VEGFR2) was assessed. About 40 μM of 734THIF and 784THIF have the best effect on inhibiting the proliferation of HepG2 cells under hypoxic conditions. At a concentration of 40 μM, 784THIF significantly inhibits COX-2 expression in pre-hypoxia conditions compared to 734THIF, with an inhibition rate of 67.73%. Additionally, 40 μM 784THIF downregulates the expression of hypoxic, inflammatory, and metastatic-related proteins, regulates oxidative stress, and inhibits the expression of anti-apoptotic proteins. The uptake by HepG2 confirmed higher 784THIF level and slower degradation characteristics under post- or pre-hypoxic conditions. In conclusion, our results showed that 784THIF had better anti-cancer effects and cellular uptake than 734THIF.

Particulate Matter and Its Molecular Effects on Skin: Implications for Various Skin Diseases

Particulate matter (PM) is a harmful air pollutant composed of chemicals and metals which affects human health by penetrating both the respiratory system and skin, causing oxidative stress and inflammation. This review investigates the association between PM and skin disease, focusing on the underlying molecular mechanisms and specific disease pathways involved. Studies have shown that PM exposure is positively associated with skin diseases such as atopic dermatitis, psoriasis, acne, and skin aging. PM-induced oxidative stress damages lipids, proteins, and DNA, impairing cellular functions and triggering inflammatory responses through pathways like aryl hydrocarbon receptor (AhR), NF-κB, and MAPK. This leads to increased production of inflammatory cytokines and exacerbates skin conditions. PM exposure exacerbates AD by triggering inflammation and barrier disruption. It disrupts keratinocyte differentiation and increases pro-inflammatory cytokines in psoriasis. In acne, it increases sebum production and inflammatory biomarkers. It accelerates skin aging by degrading ECM proteins and increasing MMP-1 and COX2. In conclusion, PM compromises skin health by penetrating skin barriers, inducing oxidative stress and inflammation through mechanisms like ROS generation and activation of key pathways, leading to cellular damage, apoptosis, and autophagy. This highlights the need for protective measures and targeted treatments to mitigate PM-induced skin damage.

Strategic Design of Hemi-Isoindigo Polymer for a Highly Sensitive and Selective All-Printed Flexible Nitrogen Dioxide Chemiresistive Sensor

The study has developed two hemi-isoindigo (HID)-based polymers for printed flexible resistor-type nitrogen oxide (NO2) sensors: poly[2-ethylhexyl 3-((3'",4'-bis(dodecyloxy)-3,4-dimethoxy-[2,2':5',2'"-terthiophen]-5-yl)methylene)-2-oxoindoline-1-carboxylate] (P1) and poly[2-ethylhexyl 2-oxo-3-((3,3'",4,4'-tetrakis(dodecyloxy)-[2,2':5',2'"-terthiophen]-5-yl)methylene)indoline-1-carboxylate] (P2). These polymers feature thermally removable carbamate side chains on the HID units, providing solubility and creating molecular cavities after thermal annealing. These cavities enhance NO2 diffusion, and the liberated unsubstituted amide ─C(═O)NH─ groups readily form robust double hydrogen bonds (DHB), as demonstrated by computer simulations. Furthermore, both polymers possess elevated highest occupied molecular orbital (HOMO) energy levels of -4.74 and -4.77 eV, making them highly susceptible to p-doping by NO2. Gas sensors fabricated from P1 and P2 films, anneal under optimized conditions to partially remove carbamate side chains, exhibit remarkable sensitivities of +1400% ppm-1 and +3844% ppm-1, and low detection limit (LOD) values of 514 ppb and 38.9 ppb toward NO2, respectively. These sensors also demonstrate excellent selectivity for NO2 over other gases.

Natural Compounds in Non-Melanoma Skin Cancer: Prevention and Treatment

The elevated occurrence of non-melanoma skin cancer (NMSC) and the adverse effects associated with available treatments adversely impact the quality of life in multiple dimensions. In connection with this, there is a necessity for alternative approaches characterized by increased tolerance and lower side effects. Natural compounds could be employed due to their safety profile and effectiveness for inflammatory and neoplastic skin diseases. These anti-cancer drugs are often derived from natural sources such as marine, zoonotic, and botanical origins. Natural compounds should exhibit anti-carcinogenic actions through various pathways, influencing apoptosis potentiation, cell proliferation inhibition, and metastasis suppression. This review provides an overview of natural compounds used in cancer chemotherapies, chemoprevention, and promotion of skin regeneration, including polyphenolic compounds, flavonoids, vitamins, alkaloids, terpenoids, isothiocyanates, cannabinoids, carotenoids, and ceramides.

Challenges of current treatment and exploring the future prospects of nanoformulations for treatment of atopic dermatitis

Atopic dermatitis (AD) is a predominant and deteriorating chronic inflammation of the skin, categorized by a burning sensation and eczematous lesions in diverse portions of the body. The treatment of AD is exclusively focused to limit the itching, reduce inflammation, and repair the breached barrier of the skin. Several therapeutic agents for the treatment and management of AD have been reported and are in use in clinics. However, the topical treatment of AD has been an unswerving challenge for the medical fraternity owing to the impaired skin barrier function in this chronic skin condition. To surmount the problems of conventional drug delivery systems, numerous nanotechnology-based formulations are emerging as alternative new modalities for AD. Latter enhances the bioavailability and delivery to the target disease site, improves drug permeation and therapeutic efficacy with reduced systemic and off-target side effects, and thus improves patient health and promotes compliance. This review aims to describe the various pathophysiological events involved in the occurrence of AD, current challenges in treatment, evidence of molecular markers of AD and its management, combinatorial treatment options, and the intervention of nanotechnology-based formulations for AD therapeutics.

Mechanochemical preparation of red clover extract/β-cyclodextrin dispersion: Enhanced water solubility and activities in alleviating high-fat diet-induced lipid accumulation and gut microbiota dysbiosis in mice

Red clover (RC) extract is rich in isoflavones (formononetin and biochanin A) that have various biological functions. However, its low water solubility limits its bioavailability. In this study, an RC extract/β-cyclodextrin (RC/β-CD) dispersion was prepared by ball milling to enhance its water solubility and biological availability. The water solubility of formononetin and biochanin A was 34.45 and 13.65 μg/mL (increased to 3.11 and 2.14 times higher than that of RC alone), respectively. The alleviating effects of the dispersion on lipid accumulation and gut microbiota were evaluated in mice. The RC/β-CD dispersion showed a better effect on inhibiting lipid accumulation, especially on total triglycerides. The dispersion group had a higher relative abundance of Akkermansia, Muribaculaceae, and Bacteroides than RC alone, along with a higher level of acetic and butyric acid. The study provides a feasible way for improving the bioaccessibility and bioactivity of RC isoflavones in red clover.

Hesperidin Exhibits Protective Effects against PM2.5-Mediated Mitochondrial Damage, Cell Cycle Arrest, and Cellular Senescence in Human HaCaT Keratinocytes

Particulate matter 2.5 (PM_2.5) exposure can trigger adverse health outcomes in the human skin, such as skin aging, wrinkles, pigment spots, and atopic dermatitis. PM_2.5 is associated with mitochondrial damage and the generation of reactive oxygen species (ROS). Hesperidin is a bioflavonoid that exhibits antioxidant and anti-inflammatory properties. This study aimed to determine the mechanism underlying the protective effect of hesperidin on human HaCaT keratinocytes against PM_2.5-induced mitochondrial damage, cell cycle arrest, and cellular senescence. Human HaCaT keratinocytes were pre-treated with hesperidin and then treated with PM_2.5. Hesperidin attenuated PM_2.5-induced mitochondrial and DNA damage, G₀/G₁ cell cycle arrest, and SA-βGal activity, the protein levels of cell cycle regulators, and matrix metalloproteinases (MMPs). Moreover, treatment with a specific c-Jun N-terminal kinase (JNK) inhibitor, SP600125, along with hesperidin markedly restored PM_2.5-induced cell cycle arrest and cellular senescence. In addition, hesperidin significantly reduced the activation of MMPs, including MMP-1, MMP-2, and MMP-9, by inhibiting the activation of activator protein 1. In conclusion, hesperidin ameliorates PM_2.5-induced mitochondrial damage, cell cycle arrest, and cellular senescence in human HaCaT keratinocytes via the ROS/JNK pathway.

Food bioactives lowering risks of chronic diseases induced by fine particulate air pollution: a comprehensive review

Airborne particulate matter (PM) exerts huge negative impacts on human health worldwide, not only targeting the respiratory system but more importantly inducing and aggravating associated chronic diseases like asthma, lung cancer, atherosclerosis, diabetes mellitus and Alzheimer diseases. Food-derived bioactive compounds like vitamins, dietary polyphenols, omega-3 polyunsaturated fatty acids and sulforaphane are feasible alternative therapeutic approaches against PM-mediated potential health damages, drawing great attention in recent years. In this review, the association between PM exposure and risks of developing chronic diseases, and the detailed mechanisms underlying the detrimental effects of PM will be discussed. Subsequently, principal food-derived bioactive compounds, with emphasize on the preventative or protective effects against PM, along with potential mechanisms will be elucidated. This comprehensive review will discuss and present current research findings to reveal the nutritional intervention as a preventative or therapeutic strategy against ambient air pollution, thereby lowering the risk of developing chronic diseases.

The circular RNA circTXNRD1 promoted ambient particulate matter-induced inflammation in human bronchial epithelial cells by regulating miR-892a/COX-2 axis

Particulate matter (PM)-induced airway inflammation contributes to the development and exacerbation of chronic airway diseases. Circular RNA (circRNA) is a new class of non-coding RNA that participates in gene regulation in various respiratory diseases, but the regulatory role of circRNA in PM-induced airway inflammation has not been fully elucidated. In this study, we performed the human circRNA microarray to reveal differentially expressed circRNAs in PM-induced human bronchial epithelial cells (HBECs). A total of 176 upregulated and 15 downregulated circRNAs were identified. Of these, a new circRNA termed circTXNRD1 was upregulated by PM exposure in a dose- and time-dependent manner. Knockdown of circTXNRD1 significantly attenuated PM-induced expression of proinflammatory cytokine interleukin 6 (IL-6). CircRNA pull-down, dual-luciferase reporter assay and fluorescence in situ hybridization showed that circTXNRD1 acted as an endogenous sponge to decrease miR-892a levels in HBECs. Downregulation of miR-892a could increase cyclooxygenase-2 (COX-2) expression and eventually promote IL-6 secretion in PM-induced HBECs. Taken together, our findings reveal circTXNRD1 as a novel inflammatory mediator in PM-induced inflammation in HBECs via regulating miR-892a/COX-2 axis. These results provide new insight into the biological mechanism underlying PM-induced inflammation in chronic airway diseases.

Role of Phenolic Compounds in Human Disease: Current Knowledge and Future Prospects

Inflammation is a natural protective mechanism that occurs when the body's tissue homeostatic mechanisms are disrupted by biotic, physical, or chemical agents. The immune response generates pro-inflammatory mediators, but excessive output, such as chronic inflammation, contributes to many persistent diseases. Some phenolic compounds work in tandem with nonsteroidal anti-inflammatory drugs (NSAIDs) to inhibit pro-inflammatory mediators' activity or gene expression, including cyclooxygenase (COX). Various phenolic compounds can also act on transcription factors, such as nuclear factor-κB (NF-κB) or nuclear factor-erythroid factor 2-related factor 2 (Nrf-2), to up-or downregulate elements within the antioxidant response pathways. Phenolic compounds can inhibit enzymes associated with the development of human diseases and have been used to treat various common human ailments, including hypertension, metabolic problems, incendiary infections, and neurodegenerative diseases. The inhibition of the angiotensin-converting enzyme (ACE) by phenolic compounds has been used to treat hypertension. The inhibition of carbohydrate hydrolyzing enzyme represents a type 2 diabetes mellitus therapy, and cholinesterase inhibition has been applied to treat Alzheimer's disease (AD). Phenolic compounds have also demonstrated anti-inflammatory properties to treat skin diseases, rheumatoid arthritis, and inflammatory bowel disease. Plant extracts and phenolic compounds exert protective effects against oxidative stress and inflammation caused by airborne particulate matter, in addition to a range of anti-inflammatory, anticancer, anti-aging, antibacterial, and antiviral activities. Dietary polyphenols have been used to prevent and treat allergy-related diseases. The chemical and biological contributions of phenolic compounds to cardiovascular disease have also been described. This review summarizes the recent progress delineating the multifunctional roles of phenolic compounds, including their anti-inflammatory properties and the molecular pathways through which they exert anti-inflammatory effects on metabolic disorders. This study also discusses current issues and potential prospects for the therapeutic application of phenolic compounds to various human diseases.

Pterostilbene Attenuates Particulate Matter-Induced Oxidative Stress, Inflammation and Aging in Keratinocytes

Particulate matter (PM) is the main indicator of air pollutants, and it may increase the level of reactive oxygen species (ROS) in keratinocytes, leading to skin inflammation, aging, and decreased moisturizing ability. Pterostilbene (PTS) is a dimethylated analog of resveratrol that has antioxidant effects. However, the molecular mechanisms of PTS in preventing PM-induced keratinocyte inflammation and aging have not been investigated yet. Therefore, we used PM-induced human keratinocytes to investigate the protective mechanisms of PTS. The results showed that 20 μM PTS had no toxicity to HaCaT keratinocytes and significantly reduced PM-induced intracellular ROS production. In addition, nuclear translocation of the aryl hydrocarbon receptor (AHR) was inhibited by PTS, leading to reduced expression of its downstream CYP1A1. PTS further inhibited PM-induced MAPKs, inflammation (COX-2), and aging (MMP-9) protein cascades, and rescued moisturizing (AQP-3) protein expression. We analyzed the PTS content in cells at different time points and compared the concentration required for PTS to inhibit the target proteins. Finally, we used the skin penetration assay to show that the PTS essence mainly exists in the epidermal layer and did not enter the system circulation. In conclusion, PTS could protect HaCaT keratinocytes from PM-induced damage and has the potential to become a cosmetic ingredient.

Flavonoids in Skin Senescence Prevention and Treatment

Skin aging is associated with the accumulation of senescent cells and is related to many pathological changes, including decreased protection against pathogens, increased susceptibility to irritation, delayed wound healing, and increased cancer susceptibility. Senescent cells secrete a specific set of pro-inflammatory mediators, referred to as a senescence-associated secretory phenotype (SASP), which can cause profound changes in tissue structure and function. Thus, drugs that selectively eliminate senescent cells (senolytics) or neutralize SASP (senostatics) represent an attractive therapeutic strategy for age-associated skin deterioration. There is growing evidence that plant-derived compounds (flavonoids) can slow down or even prevent aging-associated deterioration of skin appearance and function by targeting cellular pathways crucial for regulating cellular senescence and SASP. This review summarizes the senostatic and senolytic potential of flavonoids in the context of preventing skin aging.

Anti-pollution skincare: Research on effective ways to protect skin from particulate matter

While there is increasing interest in anti-pollution care to particulate matter (PM), there has been no research evaluating the efficacy of skin care products in a real-world setting. Our objective was to find effective ways to protect skin from PM. In total, 64 volunteers whose skin was classified as reactive to PM concentration in the previous study were enrolled. Through split-face study, different combinations of skin care products (barrier cream, barrier cream/micellar water, antioxidant, and antioxidant/micellar water) were applied for 4 weeks during the high-PM period. The biophysical properties were measured, and a facial analysis system was used to evaluate skin condition at days 0, 14, and 28. The concentrations of PM and daily events that may affect skin conditions were also recorded. The mean concentration levels of PM₁₀ and PM_2.5 from days 0 to 14 were higher in the barrier cream group than in the antioxidant group. For each group, aside from skin tone in the antioxidant/micellar water group, there were no statistically significant differences in skin measurements before and after the application, which reflects no aggravation in skin condition during high-PM periods. Intergroup analysis showed no differences in skin measurements among the four groups from day 0 to day 14, from day 14 to day 28, and from day 0 to 28. For anti-pollution care, maintaining skin barrier function using barrier cream seems to be sufficient in individuals sensitive to PM.

Antineuroinflammatory Effects of 7,3',4'-Trihydroxyisoflavone in Lipopolysaccharide-Stimulated BV2 Microglial Cells through MAPK and NF-κB Signaling Suppression

Neuroinflammation—a common pathological feature of neurodegenerative disorders such as Alzheimer’s disease—is mediated by microglial activation. Thus, inhibiting microglial activation is vital for treating various neurological disorders. 7,3’,4’-Trihydroxyisoflavone (THIF)—a secondary metabolite of the soybean compound daidzein—possesses antioxidant and anticancer properties. However, the effects of 7,3’,4’-THIF on microglial activation have not been explored. In this study, antineuroinflammatory effects of 7,3’,4’-THIF in lipopolysaccharide (LPS)-stimulated BV2 microglial cells were examined. 7,3’,4’-THIF significantly suppressed the production of the proinflammatory mediators nitric oxide (NO), inducible nitric oxide synthase (iNOS), and cyclooxygenase-2 (COX-2) as well as of the proinflammatory cytokine interleukin-6 (IL-6) in LPS-stimulated BV2 microglial cells. Moreover, 7,3’,4’-THIF markedly inhibited reactive oxygen species (ROS) generation. Western blotting revealed that 7,3’,4’-THIF diminished LPS-induced phosphorylation of extracellular signal-regulated kinase (ERK), c-Jun N-terminal kinase (JNK), glycogen synthase kinase-3β (GSK-3β), and nuclear factor kappa B (NF-κB). Overall, 7,3’,4’-THIF exerts antineuroinflammatory effects against LPS-induced microglial activation by suppressing mitogen-activated protein kinase (MAPK) and NF-κB signaling, ultimately reducing proinflammatory responses. Therefore, these antineuroinflammatory effects of 7,3’,4’-THIF suggest its potential as a therapeutic agent for neurodegenerative disorders.

Application of green tea catechins, polysaccharides, and flavonol prevent fine dust induced bronchial damage by modulating inflammation and airway cilia

Airborne fine dust particles (FDPs) have been identified as major toxins in air pollution that threaten human respiratory health. While searching for an anti-FDP reagent, we found that green tea extract (GTE) and fractions rich in flavonol glycosides (FLGs) and crude tea polysaccharides (CTPs) had protective effects against FDP-stimulated cellular damage in the BEAS-2B airway epithelial cell line. The GTE, FLGs, and CTPs significantly increased viability and lowered oxidative stress levels in FDP-treated cells. Combined treatment with GTE, FLGs, and CTPs also exerted synergistic protective effects on cells and attenuated FDP-induced elevations in inflammatory gene expression. Moreover, the green tea components increased the proportion of ciliated cells and upregulated ciliogenesis in the airway in FDP-stimulated BEAS-2B cells. Our findings provide insights into how natural phytochemicals protect the airway and suggest that green tea could be used to reduce FDP-induced airway damage as an ingredient in pharmaceutical, nutraceutical, and also cosmeceutical products.

Impact of airborne particulate matter on skin: a systematic review from epidemiology to in vitro studies

BACKGROUND

Air pollution is killing close to 5 million people a year, and harming billions more. Air pollution levels remain extremely high in many parts of the world, and air pollution-associated premature deaths have been reported for urbanized areas, particularly linked to the presence of airborne nano-sized and ultrafine particles.

MAIN TEXT

To date, most of the research studies did focus on the adverse effects of air pollution on the human cardiovascular and respiratory systems. Although the skin is in direct contact with air pollutants, their damaging effects on the skin are still under investigation. Epidemiological data suggested a correlation between exposure to air pollutants and aggravation of symptoms of chronic immunological skin diseases. In this study, a systematic literature review was conducted to understand the current knowledge on the effects of airborne particulate matter on human skin. It aims at providing a deeper understanding of the interactions between air pollutants and skin to further assess their potential risks for human health.

CONCLUSION

Particulate matter was shown to induce a skin barrier dysfunction and provoke the formation of reactive oxygen species through direct and indirect mechanisms, leading to oxidative stress and induced activation of the inflammatory cascade in human skin. Moreover, a positive correlation was reported between extrinsic aging and atopic eczema relative risk with increasing particulate matter exposure.

Oxidative contribution of air pollution to extrinsic skin ageing

•Epidemiological evidence links exposure to poor air quality to lentigines and wrinkles. •Experimental studies provide mechanistic explanations involving oxidative stress. •Polluted air may hasten skin ageing through indirect systemic effects via the lung and/or direct effects on cutaneous tissue. •Prevention measures would need to combine strategies that target both ‘routes’. •Air pollution is one of several environmental stressors that combined, may have additive/synergistic effects on the skin.

Glycofullerenes Inhibit Particulate Matter Induced Inflammation and Loss of Barrier Proteins in HaCaT Human Keratinocytes

Exposure to particulate matter (PM) has been linked to pulmonary and cardiovascular dysfunctions, as well as skin diseases, etc. PM impairs the skin barrier functions and is also involved in the initiation or exacerbation of skin inflammation, which is linked to the activation of reactive oxygen species (ROS) pathways. Fullerene is a single C₆₀ molecule which has been reported to act as a good radical scavenger. However, its poor water solubility limits its biological applications. The glyco-modification of fullerenes increases their water solubility and anti-bacterial and anti-virus functions. However, it is still unclear whether it affects their anti-inflammatory function against PM-induced skin diseases. Hence, glycofullerenes were synthesized to investigate their effects on PM-exposed HaCaT human keratinocytes. Our results showed that glycofullerenes could reduce the rate of PM-induced apoptosis and ROS production, as well as decrease the expression of downstream mitogen-activated protein kinase and Akt pathways. Moreover, PM-induced increases in inflammatory-related signals, such as cyclooxygenase-2, heme oxygenase-1, and prostaglandin E2, were also suppressed by glycofullerenes. Notably, our results suggested that PM-induced impairment of skin barrier proteins, such as filaggrin, involucrin, repetin, and loricrin, could be reduced by pre-treatment with glycofullerenes. The results of this study indicate that glycofullerenes could be potential candidates for treatments against PM-induced skin diseases and that they exert their protective effects via ROS scavenging, anti-inflammation, and maintenance of the expression of barrier proteins.

Effects of Microwave-Assisted Opuntia Humifusa Extract in Inhibiting the Impacts of Particulate Matter on Human Keratinocyte Skin Cell

Particulate matter (PM) is one of the most important factors causing serious skin diseases, due to its generation of reactive oxygen species (ROS) over the course of long-term exposure. As a source of natural antioxidants, Opuntia humifusa (O. humifusa) is a potential candidate for the design of advanced formulations to prevent PM’s harmful effects. Unfortunately, its high viscosity does not allow it to be utilized in these formulations. In this present study, a new approach to the extract of O. humifusa using high-power microwave treatment, namely microwave-assisted O. humifusa extract (MA-OHE), was investigated. The results indicated that MA-OHE not only is a reasonable viscosity extract, but also enhances O. humifusa’s antioxidant properties. Additionally, this study also found that MA-OHE exhibited outstanding antioxidant and anti-inflammatory activities in eliminating PM’s effects, due to suppression of AhR degradation, ROS production, and COX-2 and MMP-9 expression in HaCaT keratinocytes. It is believed that MA-OHE is a potential cosmeceutical ingredient that could be utilized to prevent PM-induced skin oxidative stress and inflammation.

LncRNA RP6-65G23.1 accelerates proliferation and inhibits apoptosis via p-ERK1/2/p-AKT signaling pathway on keratinocytes

Long non-coding RNAs (LncRNAs) play essential roles in the development of various diseases including hepatic carcinoma, melanoma, and psoriasis. Meanwhile, lncRNA-RP6-65G23.1 was upregulated in psoriasis. However, it is still unclear whether lncRNA-RP6-65G23.1 expression is upregulated and contributes to keratinocytes proliferation and apoptosis, and which mechanisms are responsible for these processes. The aims of this study are to address these issues. RP6-65G23.1 was significantly upregulated in M5-stimulated keratinocytes and stimulated the proliferation and inhibited the apoptosis of HaCaT cells. Knockdown of RP6-65G23.1 resulted in defects of growth and increased rates of apoptosis in HaCaT cells, while overexpression of RP6-65G23.1 manifested the opposite effects. Consistently, the expression of antiapoptotic proteins Bcl-xl and Bcl2 were decreased in RP6-65G23.1-knockdown cells but elevated in RP6-65G23.1 overexpression cells. In addition, RP6-65G23.1 depletion blunted the activity of extracellular regulated kinase 1/2 (ERK1/2) and AKT signaling pathways and induced G₁ /S-growth arrest. By contrast, overexpression of RP6-65G23.1 activates the ERK1/2 and AKT signaling pathways and inhibits the expression of p21 and p27 in an AKT-dependent manner leading to promote the G1/S progression. Our results suggested that lncRNA-RP6-65G23.1 would contribute to the pathogenesis of psoriasis by regulating the proliferation and apoptosis of keratinocytes via the p-ERK1/2 and p-AKT pathways.

Nanotechnology meets atopic dermatitis: Current solutions, challenges and future prospects. Insights and implications from a systematic review of the literature

Atopic dermatitis is a chronic, relapsing, non-contiguous, exudative eczema/dermatitis, which represents a complex, multi-factorial disorder, due to an impairment of the stratum corneum barrier. Currently available drugs have a low skin bioavailability and may give rise to severe adverse events. Nanotechnologies, including nano-particles, liposomes, nano-gels, nano-mixtures, nano-emulsions and other nano-carriers, offer unprecedented solutions to these issues, enabling: i) the management of different clinical forms of atopic dermatitis, especially the recalcitrant ones, i) a better bio-availability and trans-dermal drug targeted delivery at the inflammation site, ii) dose control, iii) significant improvements both in clinical symptoms and immune responses, iv) with less adverse events being reported and a better safety profile. However, some nano-sized structures could amplify and even worsen symptoms in particularly susceptible individuals. Furthermore, most studies included in the present systematic review have been conducted in-vitro or in-vivo, with few randomized controlled clinical trials (RCTs). Future investigations should adopt this design in order to enable scholars achieving robust findings and evidence. Therefore, given the above-mentioned shortcomings, further research in the field is urgently warranted.

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Atopic dermatitis is a chronic, relapsing eczema/dermatitis, due to an impairment of the stratum corneum barrier.

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Currently available drugs have a low skin bioavailability and may give rise to severe adverse events.

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Nanotechnologies offer unprecedented solutions, enabling the management of different clinical forms of atopic dermatitis.

Can Plant Phenolic Compounds Protect the Skin from Airborne Particulate Matter?

The skin is directly exposed to the polluted atmospheric environment, and skin diseases, such as atopic dermatitis and acne vulgaris, can be induced or exacerbated by airborne particulate matter (PM). PM can also promote premature skin aging with its accompanying functional and morphological changes. PM-induced skin diseases and premature skin aging are largely mediated by reactive oxygen species (ROS), and the harmful effects of PM may be ameliorated by safe and effective natural antioxidants. Experimental studies have shown that the extracts and phenolic compounds derived from many plants, such as cocoa, green tea, grape, pomegranate, and some marine algae, have antioxidant and anti-inflammatory effects on PM-exposed cells. The phenolic compounds can decrease the levels of ROS in cells and/or enhance cellular antioxidant capacity and, thereby, can attenuate PM-induced oxidative damage to nucleic acids, proteins, and lipids. They also lower the levels of cytokines, chemokines, cell adhesion molecules, prostaglandins, and matrix metalloproteinases implicated in cellular inflammatory responses to PM. Although there is still much research to be done, current studies in this field suggest that plant-derived phenolic compounds may have a protective effect on skin exposed to high levels of air pollution.

Water-Soluble Fullerenol C60(OH)36 toward Effective Anti-Air Pollution Induced by Urban Particulate Matter in HaCaT Cell

Particulate matter (PM), a widespread air pollutant, consists of a complex mixture of solid and liquid particles suspended in air. Many diseases have been linked to PM exposure, which induces an imbalance in reactive oxygen species (ROS) generated in cells, and might result in skin diseases (such as aging and atopic dermatitis). New techniques involving nanomedicine and nano-delivery systems are being rapidly developed in the medicinal field. Fullerene, a kind of nanomaterial, acts as a super radical scavenger. Lower water solubility levels limit the bio-applications of fullerene. Hence, to improve the water solubility of fullerene, while retaining its radical scavenger functions, a fullerene derivative, fullerenol C₆₀(OH)₃₆, was synthesized, to examine its biofunctions in PM-exposed human keratinocyte (HaCaT) cells. The PM-induced increase in ROS levels and expression of phosphorylated mitogen-activated protein kinase and Akt could be inhibited via fullerenol pre-treatment. Furthermore, the expression of inflammation-related proteins, cyclooxygenase-2, heme oxygenase-1, and prostaglandin E2 was also suppressed. Fullerenol could preserve the impaired state of skin barrier proteins (filaggrin, involucrin, repetin, and loricrin), which was attributable to PM exposure. These results suggest that fullerenol could act against PM-induced cytotoxicity via ROS scavenging and anti-inflammatory mechanisms, and the maintenance of expression of barrier proteins, and is a potential candidate compound for the treatment of skin diseases.

Improvement of Skin Penetration, Antipollutant Activity and Skin Hydration of 7,3',4'-Trihydroxyisoflavone Cyclodextrin Inclusion Complex

As is known, many antioxidants from plant extracts have been used as additives in skincare products to prevent skin damage following overexposure to environmental pollutants. 7,3′,4′-trihydroxyisoflavone (734THIF), an isoflavone compound, possesses various biological activities, including antioxidant, antityrosinase, photodamage protection, and anticancer effects. Unfortunately, 734THIF has poor water solubility, which limits its skin penetration and absorption, and subsequently influences its biological activity. The aim of the present study was to investigate the mechanisms for the improvement in water solubility and skin penetration of 2-hydroxypropyl-β-cyclodextrin (HPBCD) inclusion complex with 734THIF (5-7HP). We also determined its photostability, antipollutant activity in HaCaT keratinocytes, and moisturizing effect in human subjects. Our results showed that 734THIF was embedded into the lipophilic inner cavity of HPBCD and its water solubility and skin penetration were thereby improved through amorphous transformation, surface area enhancement, and hydrogen bonding formation between 734THIF and HPBCD. In addition, 5-7HP inhibited PM-induced ROS generation and then downregulated ROS-mediated COX-2 and MMP9 production and AQP-3 consumption by inhibiting the phosphorylation of MAPKs. Consequently, we suggest that 5-7HP is a safe and photostable topical ingredient to enhance the skin penetration of 734THIF and skin hydration, and therefore 5-7HP may be used as an antipollutant additive in skin care products.

Diphlorethohydroxycarmalol Attenuates Fine Particulate Matter-Induced Subcellular Skin Dysfunction

The skin, the largest organ in humans, is exposed to major sources of outdoor air pollution, such as fine particulate matter with a diameter ≤ 2.5 µm (PM_2.5). Diphlorethohydroxycarmalol (DPHC), a marine-based compound, possesses multiple activities including antioxidant effect. In the present study, we evaluated the protective effect of DPHC on PM_2.5-induced skin cell damage and elucidated the underlying mechanisms in vitro and in vivo. The results showed that DPHC blocked PM_2.5-induced reactive oxygen species generation in human keratinocytes. In addition, DPHC protected cells against PM_2.5-induced DNA damage, endoplasmic reticulum stress, and autophagy. HR-1 hairless mice exposed to PM_2.5 showed lipid peroxidation, protein carbonylation, and increased epidermal height, which were inhibited by DPHC. Moreover, PM_2.5 induced apoptosis and mitogen-activated protein kinase (MAPK) protein expression; however, these changes were attenuated by DPHC. MAPK inhibitors were used to elucidate the molecular mechanisms underlying these actions, and the results demonstrated that MAPK signaling pathway may play a key role in PM_2.5-induced skin damage.

Discovery of 3-Amino-2-Hydroxypropoxyisoflavone Derivatives as Potential Anti-HCV Agents

Synthesis and anti-hepatitis C virus (anti-HCV) effects of certain 3-amino-2-hydroxy-propoxy isoflavone derivatives, 6a–i, were described. The known 3-(3,4-dimethoxyphenyl)-7-(oxiran-2-ylmethoxy)-4H-chromen-4-one (5) was reacted with substituted amines to give the desired isoflavone derivatives, 6a–i. Among them, 7-{3-[(3,4-dimethoxy-phenethyl)amino]-2-hydroxypropoxy}-3-(3,4-dimethoxyphenyl)-4H-chromen-4-one (6b) was the most active, exhibiting approximately 2-fold higher anti-HCV effects than standard antiviral drug ribavirin (EC₅₀ of 6.53 vs. 13.16 μM). In addition, compound 6b was less cytotoxic than ribavirin. The selectivity index (SI) of 6b is approximately 2.6-fold higher than ribavirin. The compounds 6e, 6h, and 6i were also found to possess higher anti-HCV effects than ribavirin. Compound 6b was found to inhibit the HCV RNA expression in Ava5 cells in a dose-dependent manner; furthermore, we found that the antiviral mechanism of compounds 6b, 6e, 6h, and 6i gave rise to induction of HO-1 expression. With the HO-1 promoter-based analysis, we found compounds 6b, 6e, 6h, and 6i induced HO-1 expression through increasing Nrf-2 binding activity. Taken together, compound 6b may serve as a potential lead compound for developing novel anti-HCV agents.