Cytotoxicity In Keratinocytes Research Articles

NADES-Based Extracts of Selected Medicinal Herbs as Promising Formulations for Cosmetic Usage

As a functional extraction medium, natural deep eutectic solvents (NADESs) can dissolve various plant metabolites. Those solvents provide untapped potential for creating novel green extracts with distinctive phytochemical signatures and unique biological activities. This is particularly relevant given the rising need for eco-friendly and sustainable skin care products. The main aim of this work was to optimize the most efficient natural deep eutectic solvents (NADESs) for extracting bioactives from 18 medicinal herbs applicable to the cosmetic industry. Selection of the most potent herbs involved assessing their conventional extracts for tyrosinase inhibition, antioxidant activity, and keratinocyte cytotoxicity. Moreover, we analyzed the phenolic profile using ultra-high-pressure liquid chromatography/mass spectrometry (UHPLC/MS) and spectrophotometric assays such as total phenolic (TPC) and flavonoid content (TFC). Using the COSMO-RS method, we modeled the solubility of 12 phenolics in 64 virtual NADESs and selected the 7 most promising ones for further experimental validation. NADESs, including betaine-urea, betaine-proline, and betaine-lysine, were computationally chosen and demonstrated the highest levels of TPC and antioxidative capacity, as confirmed by in vitro assays. The proposed combination of NADES herbal extracts represents a promising natural constituent for the cosmetic industry.

Encapsulation of Lavandula austroapennina N.G. Passal., Tundis & Upson extracts: Focus on leaf and stem enriched liposome for cosmeceutical innovation

In the framework aimed at valorizing Lavandula austroapennina N.G. Passal., Tundis & Upson, an endemic species of the Apennine mountains of southern Italy, through the deep investigation of its organ chemical composition and bioactivity, innovative cosmeceutical applications are of interest. Thus, lipophilic and alcoholic extracts, at dose levels avoiding cytotoxicity in keratinocytes, were encapsulated into liposomes by applying thin-film hydration method. This was aimed to overcome known plant extract issues, such as poor solubility, high instability, and low skin permeation. The lipid-based vesicles were characterized by particle size dimension ≤300 nm, negative charge (-8 to −20 mV) and polydispersity index <0.3. Entrapment efficiency distinguished liposomes encapsulating alcoholic extracts from corolla- and calyx for their highest flavonoids, while those with leaf- and root alcoholic extracts excelled in phenolic acids and their conjugates. Among lipophilic extracts, those from corolla, calyx and stem provided liposomes entrapping the highest lipid content. These data, together with the greater bioactivity of alcoholic leaf, and lipophilic stem extract, allowed us to further investigate these two extracts for their cosmeceutical applicability. Accordingly, extracts-containing liposomes, preliminarily characterized by ATR-FTIR spectroscopy, underwent cytotoxic and healing capability assessment towards HaCaT cells. The extracts-enriched liposomes showed a healing capacity higher than the parental extracts from which they derived. Evaluating the percutaneous absorption by Franz Cells assay, followed by UHPLC-QqTOF-HR-MS-based quali-quantitative analysis, revealed that encapsulation in liposomes improved bioactive delivery through/into a specific skin layer. These results, while suggesting the effectiveness of liposome-based nanoparticles in improving the bioavailability and biological activity of specialized metabolites, reinforce the cosmeceutical use of L. austroapennina extracts.

Cytoprotective role of human dental pulp stem cell-conditioned medium in chemotherapy-induced alopecia

BackgroundChemotherapy-induced alopecia (CIA) is a distressing adverse effect of chemotherapy, with an estimated incidence of 65% and limited treatment options. Cyclophosphamide (CYP) is a common alopecia-inducing chemotherapy agent. Human dental pulp stem cells (DPSCs) secrete several paracrine factors that up-regulate hair growth. Conditioned medium (CM) collected from DPSCs (DPSC-CM) promotes hair growth; culturing mesenchymal stem cells under hypoxic conditions can enhance this effect.MethodsThe effect of DPSC-CM cultured under normoxic (N-) and hypoxic (H-) conditions against CYP-mediated cytotoxicity in keratinocytes was examined using cell viability assay, lactate dehydrogenase (LDH) cytotoxicity assay, and apoptosis detection. The damage-response pathway was determined in a well-established CIA mouse model by analyzing macroscopic effects, histology, and apoptosis. Reverse transcription-quantitative PCR and Caspase-3/7 activity assay were used to investigate the impact of DPSC-CM on the molecular damage-response pathways in CYP-treated mice. The effect of post-CIA DPSC-CM application on post-CIA hair regrowth was analyzed by macroscopic effects and microstructure observation of the hair surface. Furthermore, to investigate the safety of DPSC-CM as a viable treatment option, the effect of DPSC-CM on carcinoma cell lines was examined by cell viability assay and a subcutaneous tumor model.ResultsIn the cell viability assay, DPSC-CM was observed to increase the number of keratinocytes over varying CYP concentrations. Furthermore, it reduced the LDH activity level and suppressed apoptosis in CYP-treated keratinocytes. DPSC-CM exhibited the cytoprotective role in vivo via the dystrophic anagen damage-response pathway. While both N-CM and H-CM downregulated the Caspase-3/7 activity level, H-CM downregulated Caspase-3 mRNA expression. The proportion of post-CIA H-CM-treated mice with > 90% normal hair was nearly twice that of vehicle- or N-CM-treated mice between days 50 and 59 post-depilation, suggesting that post-CIA H-CM application may accelerate hair regrowth and improve hair quality. Furthermore, DPSC-CM suppressed proliferation in vitro in certain carcinoma cell lines and did not promote the squamous cell carcinoma (SCC-VII) tumor growth rate in mice.ConclusionsThe potentiality of DPSC-CM and H-CM as a promising cytoprotective agent and hair regrowth stimulant, respectively, for CIA needs in-depth exploration.

Obacunone Photoprotective Effects against Solar-Simulated Radiation-Induced Molecular Modifications in Primary Keratinocytes and Full-Thickness Human Skin.

Solar radiation can cause damage to the skin, leading to various adverse effects such as sunburn, reactive oxygen species production, inflammation, DNA damage, and photoaging. To study the potential of photoprotective agents, full-thickness skin models are increasingly being used as in vitro tools. One promising approach to photoprotection involves targeting the redox-sensitive transcription factor Nrf2, which is responsible for regulating various cellular defense mechanisms, including the antioxidant response, inflammatory signaling, and DNA repair. Obacunone, a natural triterpenoid, has been identified as a potent Nrf2 agonist. The present study aims to evaluate the relevance of full-thickness (FT) skin models in photoprotection studies and to explore the potential photoprotective effects of obacunone on those models and in human keratinocytes. Phenion® full-thickness skin models and keratinocytes were incubated with increasing concentrations of obacunone and irradiated with solar-simulated radiation (SSR). Various photodamage markers were evaluated, including histological integrity, oxidative stress, apoptosis, inflammation, photoaging-related dermal markers, and photocarcinogenesis markers. Increasing doses of SSR were found to modulate various biomarkers related to sun damage in the FT skin models. However, obacunone attenuated cytotoxicity, inflammation, oxidative stress, sunburn reaction, photoaging, and photocarcinogenesis in both keratinocytes and full thickness skin models exposed to SSR. These results suggest that obacunone may have potential as a photoprotective agent for preventing the harmful effects of solar radiation on the skin.

Fabrication and characterization of bioprints with Lactobacillus crispatus for vaginal application

Bacterial vaginosis (BV) is characterized by low levels of lactobacilli and overgrowth of potential pathogens in the female genital tract. Current antibiotic treatments often fail to treat BV in a sustained manner, and > 50% of women experience recurrence within 6 months post-treatment. Recently, lactobacilli have shown promise for acting as probiotics by offering health benefits in BV. However, as with other active agents, probiotics often require intensive administration schedules incurring difficult user adherence. Three-dimensional (3D)-bioprinting enables fabrication of well-defined architectures with tunable release of active agents, including live mammalian cells, offering the potential for long-acting probiotic delivery. One promising bioink, gelatin alginate has been previously shown to provide structural stability, host compatibility, viable probiotic incorporation, and cellular nutrient diffusion. This study formulates and characterizes 3D-bioprinted Lactobacillus crispatus-containing gelatin alginate scaffolds for gynecologic applications. Different weight to volume (w/v) ratios of gelatin alginate were bioprinted to determine formulations with highest printing resolution, and different crosslinking reagents were evaluated for effect on scaffold integrity via mass loss and swelling measurements. Post-print viability, sustained-release, and vaginal keratinocyte cytotoxicity assays were conducted. A 10:2 (w/v) gelatin alginate formulation was selected based on line continuity and resolution, while degradation and swelling experiments demonstrated greatest structural stability with dual genipin and calcium crosslinking, showing minimal mass loss and swelling over 28 days. 3D-bioprinted L. crispatus-containing scaffolds demonstrated sustained release and proliferation of live bacteria over 28 days, without impacting viability of vaginal epithelial cells. This study provides in vitro evidence for 3D-bioprinted scaffolds as a novel strategy to sustain probiotic delivery with the ultimate goal of restoring vaginal lactobacilli following microbiological disturbances.

Biogenic silica microparticles as a new and sustainable cosmetic ingredient: Assessment of performance and quality parameters

The demand for sustainable products is increasing worldwide and cosmetic industry is not an exception. Besides exploring nature as source of new ingredients, their production must be sustainable and should use environmentally friendly processes. In this work, biogenic silica microparticles were synthesized from sugarcane ash, and their potential application as cosmetic and skincare ingredient was evaluated. For such application, several properties were validated, including cytotoxicity in skin keratinocytes, potential sensitization effect on skin peptides, stimulation of pro-collagen I alpha 1, wound healing capacity, as well as the ingredient stability along a storage period. Biogenic silica showed to be non-cytotoxic on skin keratinocytes, at concentrations up to 5 wt%, and non-skin sensitizer. A positive effect on the stimulation of pro-collagen I alpha 1 suggests a potential anti-ageing activity, while the migration of fibroblasts to a wounded area suggests a regenerative capacity. Under an accelerated stability study, biogenic silica showed an increase on the loss on drying, but no changes were observed on its functional properties, mainly oil absorption capacity, as well the microbiological quality, which was maintained. Overall, novel biogenic silica microparticles produced from a sustainable source are safe, stable over time and have potential to be used as a cosmetic and skincare ingredient.

Differential Effects of Histidine and Histidinamide versus Cysteine and Cysteinamide on Copper Ion-Induced Oxidative Stress and Cytotoxicity in HaCaT Keratinocytes.

Metal chelators are used for various industrial and medical purposes based on their physicochemical properties and biological activities. In biological systems, copper ions bind to certain enzymes as cofactors to confer catalytic activity or bind to specific proteins for safe storage and transport. However, unbound free copper ions can catalyze the production of reactive oxygen species (ROS), causing oxidative stress and cell death. The present study aims to identify amino acids with copper chelation activities that might mitigate oxidative stress and toxicity in skin cells exposed to copper ions. A total of 20 free amino acids and 20 amidated amino acids were compared for their copper chelation activities in vitro and the cytoprotective effects in cultured HaCaT keratinocytes exposed to CuSO4. Among the free amino acids, cysteine showed the highest copper chelation activity, followed by histidine and glutamic acid. Among the amidated amino acids, cysteinamide showed the highest copper chelation activity, followed by histidinamide and aspartic acid. CuSO4 (0.4-1.0 mM) caused cell death in a concentration-dependent manner. Among the free and amidated amino acids (1.0 mM), only histidine and histidinamide prevented the HaCaT cell death induced by CuSO4 (1.0 mM). Cysteine and cysteinamide had no cytoprotective effects despite their potent copper-chelating activities. EDTA and GHK-Cu, which were used as reference compounds, had no cytoprotective effects either. Histidine and histidinamide suppressed the CuSO4-induced ROS production, glutathione oxidation, lipid peroxidation, and protein carbonylation in HaCaT cells, whereas cysteine and cysteinamide had no such effects. Bovine serum albumin (BSA) showed copper-chelating activity at 0.5-1.0 mM (34-68 mg mL-1). Histidine, histidinamide, and BSA at 0.5-1.0 mM enhanced the viability of cells exposed to CuCl2 or CuSO4 (0.5 mM or 1.0 mM) whereas cysteine and cysteinamide had no such effects. The results of this study suggest that histidine and histidinamide have more advantageous properties than cysteine and cysteinamide in terms of alleviating copper ion-induced toxic effects in the skin.

Myricetin Nanofibers Enhanced Water Solubility and Skin Penetration for Increasing Antioxidant and Photoprotective Activities.

Excessive exposure to ultraviolet radiation (UV) can induce oxidative stress through the over-production of reactive oxygen species (ROS) on the skin. Myricetin (MYR), a natural flavonoid compound, significantly inhibited UV-induced keratinocyte damage; however, its bioavailability is limited by its poor water solubility and inefficient skin penetration ability, which subsequently influences its biological activity. The purpose of the study was to develop a myricetin nanofibers (MyNF) system of hydroxypropyl-β-cyclodextrin (HPBCD)/polyvinylpyrrolidone K120 (PVP)-loaded with MYR that would enhance the water solubility and skin penetration by changing the physicochemical characteristics of MYR, including reducing the particle size, increasing the specific surface area, and amorphous transformation. The results also revealed that the MyNF can reduce cytotoxicity in HaCaT keratinocytes when compared with MYR; additionally, MyNF had better antioxidant and photoprotective activity than raw MYR for the UVB-induced HaCaT keratinocytes damage model due to the MyNF increased water solubility and permeability. In conclusion, our results demonstrate that MyNF is a safe, photostable, and thermostable topical ingredient of antioxidant nanofibers to enhance the skin penetration of MYR and prevent UVB-induced skin damage.

Screening of Rosemary Essential Oils with Different Phytochemicals for Antioxidant Capacity, Keratinocyte Cytotoxicity, and Anti-Proliferative Activity.

Nowadays, the demand for rosemary essential oils (REOs) in the cosmetic, food, and pharmaceutical industries is increasing, and the abundant germplasm resources of rosemary provide more possibilities for functional applications. The REOs from six cultivars were selected to evaluate and compare their bioactivities. REOs have good cellular antioxidant activity in scavenging reactive oxygen species, and the technology for order preference by similarity to an ideal solution (TOPSIS)-random forest multivariate model indicated that 'Dutch Mill' REO has the best antioxidant activity, which is closely related to its verbenone content. In addition, α-pinene-dominant REOs are more toxic to human keratinocytes, which is closely related to the content of α-pinene, as revealed by multivariate analyses. Moreover, anti-proliferative assays on six cancer cell lines showed that all REOs have a higher anti-proliferative ability against human pancreatic cancer cell line SW1990 and gastric epithelial cell line NCI-N87. Among them, 'Miss Jessopp's Upright' and 'Blue Lagoon' REOs exhibit more prominent anti-proliferative activity. Our study provides a reference value for exploring the application potential of different REOs by evaluating their differences in chemical composition and bioactivity.

Arsenic Compounds Arsenic Trioxide and Tetraarsenic Oxide Attenuate 3-Methylcholanthrene-Induced Cytotoxicity in Human Keratinocytes

Arsenic Compounds Arsenic Trioxide and Tetraarsenic Oxide Attenuate 3-Methylcholanthrene-Induced Cytotoxicity in Human Keratinocytes

Streptolysin S targets the sodium-bicarbonate cotransporter NBCn1 to induce inflammation and cytotoxicity in human keratinocytes during Group A Streptococcal infection.

Group A Streptococcus (GAS, Streptococcus pyogenes) is a Gram-positive human pathogen that employs several secreted and surface-bound virulence factors to manipulate its environment, allowing it to cause a variety of disease outcomes. One such virulence factor is Streptolysin S (SLS), a ribosomally-produced peptide toxin that undergoes extensive post-translational modifications. The activity of SLS has been studied for over 100 years owing to its rapid and potent ability to lyse red blood cells, and the toxin has been shown to play a major role in GAS virulence in vivo. We have previously demonstrated that SLS induces hemolysis by targeting the chloride-bicarbonate exchanger Band 3 in erythrocytes, indicating that SLS is capable of targeting host proteins to promote cell lysis. However, the possibility that SLS has additional protein targets in other cell types, such as keratinocytes, has not been explored. Here, we use bioinformatics analysis and chemical inhibition studies to demonstrate that SLS targets the electroneutral sodium-bicarbonate cotransporter NBCn1 in keratinocytes during GAS infection. SLS induces NF-κB activation and host cytotoxicity in human keratinocytes, and these processes can be mitigated by treating keratinocytes with the sodium-bicarbonate cotransport inhibitor S0859. Furthermore, treating keratinocytes with SLS disrupts the ability of host cells to regulate their intracellular pH, and this can be monitored in real time using the pH-sensitive dye pHrodo Red AM in live imaging studies. These results demonstrate that SLS is a multifunctional bacterial toxin that GAS uses in numerous context-dependent ways to promote host cell cytotoxicity and increase disease severity. Studies to elucidate additional host targets of SLS have the potential to impact the development of therapeutics for severe GAS infections.

Mechanisms of Cd-Induced Cytotoxicity in Normal Human Skin Keratinocytes: Implication for Human Health.

Cadmium (Cd) is one of the toxic heavy metals found widely in the environment. Skin is an important target organ of Cd exposure. However, the adverse effects of Cd on human skin are still not well known. In this study, normal human skin keratinocytes (HaCaT cells) were studied for changes in cell viability, morphology, DNA damage, cycle, apoptosis, and the expression of endoplasmic reticulum (ER) stress-related genes (XBP-1, BiP, ATF-4, and CHOP) after exposure to Cd for 24 h. We found that Cd decreased cell viability in a concentration-dependent manner, with a median lethal concentration (LC50) of 11 µM. DNA damage induction was evidenced by upregulation of the level of γ-H2AX. Furthermore, Cd induced G0/G1 phase cell cycle arrest and apoptosis in a dose-dependent manner and upregulated the mRNA levels of ER stress biomarker genes (XBP-1, BiP, ATF4, and CHOP). Taken together, our results showed that Cd induced cytotoxicity and DNA damage in HaCaT cells, eventually resulting in cell cycle arrest in the G0/G1 phase and apoptosis. In addition, ER stress may be involved in Cd-induced HaCaT apoptosis. Our data imply the importance of reducing Cd pollution in the environment to reduce its adverse impacts on human skin.

Co-exposure of monocrotophos and ethanol synergistically induced cytotoxicity in keratinocytes and alveolar epithelium cells

Co-exposure of monocrotophos and ethanol synergistically induced cytotoxicity in keratinocytes and alveolar epithelium cells

Alpinetin promotes hair regeneration via activating hair follicle stem cells

BackgroundAlopecia affects millions of individuals globally, with hair loss becoming more common among young people. Various traditional Chinese medicines (TCM) have been used clinically for treating alopecia, however, the effective compounds and underlying mechanism are less known. We sought to investigate the effect of Alpinetin (AP), a compound extracted from Fabaceae and Zingiberaceae herbs, in hair regeneration.MethodsAnimal model for hair regeneration was mimicked by depilation in C57BL/6J mice. The mice were then topically treated with 3 mg/ml AP, minoxidil as positive control (PC), or solvent ethanol as vehicle control (VC) on the dorsal skin. Skin color changes which reflected the hair growth stages were monitored and pictured, along with H&E staining and hair shaft length measurement. RNA-seq analysis combined with immunofluorescence staining and qPCR analysis were used for mechanism study. Meanwhile, Gli1CreERT2; R26RtdTomato and Lgr5EGFP−CreERT2; R26RtdTomato transgenic mice were used to monitor the activation and proliferation of Gli1+ and Lgr5+ HFSCs after treatment. Furthermore, the toxicity of AP was tested in keratinocytes and fibroblasts from both human and mouse skin to assess the safety.ResultsWhen compared to minoxidil-treated and vehicle-treated control mice, topical application of AP promoted anagen initiation and delayed catagen entry, resulting in a longer anagen phase and hair shaft length. Mechanistically, RNA-seq analysis combined with immunofluorescence staining of Lef1 suggested that Lgr5+ HFSCs in lower bulge were activated by AP via Wnt signaling. Other HFSCs, including K15+, Lef1+, and Gli1+ cells, were also promoted into proliferating upon AP treatment. In addition, AP inhibited cleaved caspase 3-dependent apoptosis at the late anagen stage to postpone regression of hair follicles. More importantly, AP showed no cytotoxicity in keratinocytes and fibroblasts from both human and mouse skin.ConclusionThis study clarified the effect of AP in promoting hair regeneration by activating HFSCs via Wnt signaling. Our findings may contribute to the development of a new generation of pilatory that is more efficient and less cytotoxic for treating alopecia.

A New Design for Magnetic Poly(vinyl pivalate) for Biomedical Applications: Synthesis, Characterization, and Evaluation of Cytotoxicity in Fibroblasts, Keratinocytes, and Human Melanoma Cells

Polymers containing magnetic properties play an important role in biomedical therapies, such as embolotherapy or hyperthermia, for their differentiated properties. In this work, magnetite (Fe3O4) nanoparticles were synthesized by the coprecipitation method and dispersed into a thermoplastic matrix of poly(vinyl pivalate) through an emulsion polymerization process. The main goal was the individual encapsulation of magnetite nanoparticles to improve the magnetic response of the magneto-polymeric materials using polymerizable carboxylic acids as coating agents, minimizing the leaching of nanoparticles throughout the nanocomposite formation. For this purpose, synthesized magnetite had its surface modified by acrylic acid or methacrylic acid to improve its individual encapsulation during the polymerization step, thus generating a series of magnetic nanocomposite materials containing different amounts of magnetite intended for biomedical applications. X-ray diffractometry and TEM measurements provided a mean size of approximately 8 nm for the pure magnetite nanoparticles and a spherical morphology. Acid-functionalized Fe3O4 had a size of approximately 6 nm, while the nanocomposites showed a size of approximately 7 nm. Magnetization measurement provided a saturation magnetization value of approximately 75 emu/g and confirmed superparamagnetic behavior at room temperature. DSC analysis showed a glass transition temperature of 65 °C for poly(vinyl pivalate)-based nanocomposites. The tests realized with homopolymer and magnetic composites against different cell lineages (i.e., fibroblasts, keratinocytes, and human melanoma) to evaluate the levels of cytotoxicity showed good results in the different exposure times and concentrations used, since the obtained results showed cell viability greater than 70% compared to the control group, suggesting that the synthesized materials are very promising for medical applications.

Discrimination of hand-foot skin reaction caused by tyrosine kinase inhibitors based on direct keratinocyte toxicity and vascular endothelial growth factor receptor-2 inhibition

Tyrosine kinase inhibitors (TKIs) are molecular-targeted anticancer drugs. Their benefits are limited by dermal toxicities, including hand-foot skin reaction (HFSR), which is commonly found in skin areas subjected to friction. The present study aimed to explain the incidence of HFSR in patients treated with TKIs by focusing on keratinocyte toxicity and inhibition of vascular endothelial growth factor receptor (VEGFR), which plays an essential role in angiogenesis. Mice with gene knockout for the immunosuppressive cytokine interleukin-10 exhibited HFSR-like phenotypes, such as cytotoxicity in keratinocytes and increased number and size of blood vessels after repeated doses of regorafenib, sorafenib, and pazopanib, all of which cause high incidence of HFSR, in combination with tape-stripping mimicking skin damage at the friction site. Comprehensive examination of the direct cytotoxic effects of 21 TKIs on primary cultured human keratinocytes revealed that 18 of them reduced the cell viability dose-dependently. Importantly, the ratio of the trough concentration in patients (Ctrough) to the LC50 values of cell viability reduction was higher than unity for four HFSR-inducing TKIs, suggesting that these TKIs cause keratinocyte toxicity at clinically relevant concentrations. In addition, eight HFSR-inducing TKIs caused inhibition of VEGFR-2 kinase activity, which was validated by their ratios of Ctrough to the obtained IC50,VEGFR-2 of more than unity. All 12 TKIs with no reported incidence of HFSR exhibited less than unity values for both Ctrough/LC50,keratinocytes and Ctrough/IC50,VEGFR-2. These results suggested that a combination of keratinocyte toxicity and VEGFR-2 inhibition may explain the incidence of HFSR upon TKI usage in humans.

Surface-Modified Multifunctional Thymol-Loaded Biodegradable Nanoparticles for Topical Acne Treatment.

The present work is focused on the development of novel surface-functionalized poly(lactic-co-glycolic acid) nanoparticles loaded with thymol (TH-NPs) for topical administration enhancing thymol anti-inflammatory, antioxidant and wound healing activities against acne. TH-NPs were prepared by solvent evaporation method using different surface functionalization strategies and obtaining suitable physicochemical parameters and a good short-term stability at 4 °C. Moreover, TH-NPs skin penetration and antioxidant activity were assessed in ex vivo pig skin models. Skin penetration of TH-NPs followed the follicular route, independently of the surface charge and they were able to enhance antioxidant capacity. Furthermore, antimicrobial activity against Cutibacterium acnes was evaluated in vitro by the suspension test showing improved antibacterial performance. Using human keratinocyte cells (HaCat), cytotoxicity, cellular uptake, antioxidant, anti-inflammatory and wound healing activities were studied. TH-NPs were non-toxic and efficiently internalized inside the cells. In addition, TH-NPs displayed significant anti-inflammatory, antioxidant and wound healing activities, which were highly influenced by TH-NPs surface modifications. Moreover, a synergic activity between TH-NPs and their surface functionalization was demonstrated. To conclude, surface-modified TH-NPs had proven to be suitable to be used as anti-inflammatory, antioxidant and wound healing agents, constituting a promising therapy for treating acne infection and associated inflammation.

Generation of Stilbene Glycoside with Promising Cell Rejuvenation Activity through Biotransformation by the Entomopathogenic Fungus Beauveria bassiana.

A stilbene glycoside (resvebassianol A) (1) with a unique sugar unit, 4-O-methyl-D-glucopyranose, was identified through biotransformation of resveratrol (RSV) by the entomopathogenic fungus Beauveria bassiana to obtain a superior RSV metabolite with enhanced safety. Its structure, including its absolute configurations, was determined using spectroscopic data, HRESIMS, and chemical reactions. Microarray analysis showed that the expression levels of filaggrin, HAS2-AS1, and CERS3 were higher, while those of IL23A, IL1A, and CXCL8 were lower in the resvebassianol A-treated group than in the RSV-treated group, as confirmed by qRT-PCR. Compound 1 exhibited the same regenerative and anti-inflammatory effects as RSV with no cytotoxicity in skin keratinocytes and TNF-α/IFN-γ-stimulated HIEC-6 cells, suggesting that compound 1 is a safe and stable methylglycosylated RSV. Our findings suggest that our biotransformation method can be an efficient biosynthetic platform for producing a broad range of natural glycosides with enhanced safety.

Honokiol attenuates oxidative stress-induced cytotoxicity in human keratinocytes via activating AMPK signaling

Objective: To investigate the effect of honokiol on oxidative damage in HaCaT human keratinocytes. Methods: HaCaT cells were exposed to hydrogen peroxide (H2O2), following pretreatment with various concentrations of honokiol. The alleviating effects of honokiol on HaCaT cell viability and cell death, reactive oxygen species (ROS) production, DNA damage, mitochondrial dynamics, and inhibition of adenosine triphoaphate production against H2O2 were investigated. Western blotting analysis was used to analyze the expression levels of specific proteins. Results: Honokiol suppressed H2O2-induced cytotoxicity and DNA damage by blocking abnormal ROS accumulation. Honokiol also prevented apoptosis by inhibiting loss of mitochondrial membrane potential and release of cytochrome c from the mitochondria into the cytosol, decreasing the Bax/Bcl-2 ratio, and reducing the activity of caspase-3 in H2O2-stimulated HaCaT cells. In addition, honokiol attenuated H2O2-induced reduction of adenosine triphosphate content, and activation of AMP-activated protein kinase (AMPK) was markedly promoted by honokiol in H2O2-stimulated cells. Importantly, the anti-apoptosis and anti-proliferative activity of honokiol against H2O2 was further enhanced by adding an activator of AMPK, indicating that honokiol activated AMPK in HaCaT keratinocytes to protect against oxidative damage. Conclusions: The present results indicate that honokiol may be useful as a potential therapeutic agent against various oxidative stress-related skin diseases.

Effect of hot or warm property on skin toxicity of essential oil as penetration enhancer and its mechanism

To compare the effect of hot or warm property of Chinese medicine(CM) on the skin toxicity of essential oils(EOs) as penetration enhancer in vitro and in vivo, and explore the mechanism. EOs were extracted from WIM of Bichengqie(Litseae Fructus), Dingxiang(Flos Syzygii Aromatici), Huajiao(Pericarpium Zanthoxyli Bungeani), and Xiaohuixiang(Fructus Foeniculi) with warm property, and Ganjiang(Rhizoma Zingiberis), Gaoliangjiang(Rhizoma Alpiniae Officinari), Hujiao(Fructus Piperis), and Wuzhuyu(Fructus Evodiae Rutaecarpae) with hot property, respectively. Then the in vitro toxicity was evaluated by human keratinocyte cytotoxicity. In vivo skin irritation potency was also evaluated through pathological observation after topical administration. The components, especially those located in stratum corneum, were analyzed by GC-MS. The main components, namely monoterpenes and sesquiterpenes, of EOs extracted from CM with hot property,were detected for the interaction with keratino-lipid ceramide 3 by molecular simulation technology; and the interaction energy value was calculated based on the optimal conformation. It was found that the skin cell toxicity of EOs from CM with hot property was significantly higher than that of EOs from CM with warm property. However, there was no significant difference between them by in vivo skin irritation evaluation. Whether from CM with hot property or warm property, EOs showed a significant reduced toxicity compared with azone. Sesquiterpenes(33.56%±19.38%) were found to be one of the main components in EOs from CM with hot property, while almost no sesquiterpenes was found in EOs from CM with warm property. After topical administration of EOs from CM with hot property, sesquiterpenes were demonstrated to be prone to locate in stratum corneum. The results of molecular simulation also revealed that the interaction between sesquiterpenes and ceramide 3 was significantly stronger than that of monoterpenes(P&lt;0.01). In conclusion, the location of sesquiterpenes in stratum corneum resulted in the significant difference between in vitro skin cell toxicity and in vivo skin irritation potency. The EOs from CM with hot property shall be taken into account for further development of potent penetration enhancer.