Keratinocyte HaCaT Cells Research Articles

Preparation of High-Solid Microfibrillated Cellulose from Gelidium amansii and Characterization of Its Physiochemical and Biological Properties.

Microfibrillated cellulose (MFC) is a valuable material with wide industrial applications, particularly for the food and cosmetics industries, owing to its excellent physiochemical properties. Here, we prepared high-solid microfibrillated cellulose (HMFC) from the centrifugation of Gelidium amansii-derived MFC right after fibrillation. Dispersion properties, morphology, and structural changes were monitored during processing. HMFC has a five-fold higher solid concentration than MFC without significant changes to dispersion properties. SEM images and FTIR spectra of HMFC revealed a stable surface and structure against centrifugal forces. HMFC exhibited 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical scavenging activity, although it could not scavenge 2,2-diphenyl-1-picrylhydrazyl (DPPH). Moreover, HMFC inhibited the generation of LPS-induced excessive nitrite and radial oxygen species in murine macrophage RAW264.7 cells. Additionally, HMFC suppressed LPS-induced Keap-1 expression in the cytosol but did not alter iNOS expression. HMFC also attenuated the UVB-induced phosphorylation of p38, c-Jun N-terminal kinase (JNK) 1/2, and extracellular-signal-regulated kinase (ERK) 1/2, as well as the phosphorylation of c-Jun in the immortalized human skin keratinocyte HaCaT cells. Therefore, the application of centrifugation is suitable for producing high-solid MFC as a candidate material for anti-inflammatory and anti-oxidative marine cosmeceuticals.

Evaluation of Poly-3-Hydroxybutyrate (P3HB) Scaffolds Used for Epidermal Cells Growth as Potential Biomatrix.

Advances in tissue engineering have made possible the construction of organs and tissues with the use of biomaterials and cells. Three important elements are considered: a specific cell culture, an adequate environment, and a scaffold. The present study aimed to develop P3HB scaffolds by 3D printing and evaluate their biocompatibility with HaCaT epidermal cells, as a potential model that allows the formation of functional tissue. By using a method of extraction and purification with ethanol and acetone, a biopolymer having suitable properties for use as a tissue support was obtained. This polymer exhibited a higher molecular weight (1500 kDa) and lower contact angle (less than 90°) compared to the material obtained using the conventional method. The biocompatibility analysis reveals that the scaffold obtained using the ethanol–acetone method and produced by 3D printing without pores was not cytotoxic, did not self-degrade, and allowed high homogenous cell proliferation of HaCaT cells. In summary, it is possible to conclude that the P3HB scaffold obtained by 3D printing and a simplified extraction method is a suitable support for the homogeneous development of HaCaT keratinocyte cell lineage, which would allow the evaluation of this material to be used as a biomatrix for tissue engineering.

Molecular Characterization and Biocompatibility of Exopolysaccharide Produced by Moderately Halophilic Bacterium Virgibacillus dokdonensis from the Saltern of Kumta Coast.

The use of natural polysaccharides as biomaterials is gaining importance in tissue engineering due to their inherent biocompatibility. In this direction, the present study aims to explore the structure and biocompatibility of the EPS produced by Virgibacillus dokdonensis VITP14. This marine bacterium produces 17.3 g/L of EPS at 96 h of fermentation. The EPS was purified using ion exchange and gel permeation chromatographic methods. The porous web-like structure and elemental composition (C, O, Na, Mg, P, S) of the EPS were inferred from SEM and EDX analysis. AFM analysis revealed spike-like lumps with a surface roughness of 84.85 nm. The zeta potential value of −10 mV indicates the anionic nature of the EPS. Initial molecular characterization showed that the EPS is a heteropolysaccharide composed of glucose (25.8%), ribose (18.6%), fructose (31.5%), and xylose (24%), which are the monosaccharide units in the HPLC analysis. The FTIR spectrum indicates the presence of functional groups/bonds typical of EPSs (O-H, C-H, C-O-H, C-O, S=O, and P=O). The polymer has an average molecular weight of 555 kDa. Further, NMR analysis revealed the monomer composition, the existence of two α- and six β-glycosidic linkages, and the branched repeating unit as → 1)[α-D-Xylp-(1 → 2)-α-D-Glcp-(1 → 6)-β-D-Glcp-(1 → 5)]-β-D-Frup-(2 → 2)[β-D-Xylp-(1 → 4)]-β-D-Xylp-(1 → 6)-β-D-Fruf-(2 → 4)-β-D-Ribp-(1 →. The EPS is thermally stable till 251.4 °C. X-ray diffraction analysis confirmed the semicrystalline (54.2%) nature of the EPS. Further, the EPS exhibits significant water solubility (76.5%), water-holding capacity (266.8%), emulsifying index (66.8%), hemocompatibility (erythrocyte protection > 87%), and cytocompatibility (cell viability > 80% on RAW264.7 and keratinocyte HaCaT cells) at higher concentrations and prolongs coagulation time in APTT and PT tests. Our research unveils the significant biocompatibility of VITP14 EPS for synthesizing a variety of biomaterials.

Anti-inflammatory Effects of Myrrh Ethanol Extract on Particulate Matter-induced Skin Injury

Objectives: Myrrh have been used as a traditional remedy to treat infectious and inflammatory diseases. However, it is largely unknown whether myrrh ethanol extract could exhibit the inhibitory activities against particulate matter (PM)-induced skin injury on human keratinocytes, HaCaT cells. Therefore, this study was aimed to investigate the inhibitory activity of myrrh ethanol extract on PM-induced skin injury in HaCaT cells.Methods: To investigate the inhibitory effects of myrrh ethanol extract in HaCaT cells, the skin injury model of HaCaT cells was established under PM treatment. HaCaT keratinocyte cells were pre-treated with myrrh ethanol extract for 1 h, and then stimulated with PM. Then, the cells were harvested to measure the cell viability, reactive oxygen species (ROS), pro-inflammatory cytokines including interleukin (IL) 1-beta, IL-6, and tumor necrosis factor (TNF)-α, hyaluronidase, collagen, MMPs. In addition, we examined the mitogen activated protein kinases (MAPKs) and inhibitory kappa B alpha (Iκ-Bα) as inhibitory mechanisms of myrrh ethanol extract.Results: The treatment of myrrh ethanol extract inhibited the PM-induced cell death and ROS production in HaCaT cells. In addition, myrrh ethanol extract treatment inhibited the PM-induced elevation of IL-1beta, IL-6, and TNF-α. Also, myrrh ethanol extract treatment inhibited the increase of hyaluronidase, MMP and decrease of collagen. Furthermore, myrrh ethanol extract treatment inhibited the activation of MAPKs and the degradation of Iκ-Bα.Conclusions: Our result suggest that treatment of myrrh ethanol extract could inhibit the PM-induced skin injury via deactivation of MAPKs and nuclear factor (NF)-κB in HaCaT cells. This study could suggest that myrrh ethanol extract could be a beneficial agent to prevent skin damage or inflammation.

Photoprotective, Anti-Fungal Activity and Cytotoxicity of Capsanthin from Capsicum Annum Fruits on Mouse Skin Melanoma and AQP-3 Gene Expression in Human Keratinocyte HaCaT Cells

Background: Phytochemicals utilization in the cosmetics are the current trend in the beauty and fashion. Most women prefer the cosmetics derived from natural products over synthetic chemicals, as the natural products are devoid of undesirable side effects. Skin protection has become not only aesthetic, but also linked to health. Therefore, exploring the use of phytochemicals in cosmetic dermatology is essential. Objective: In the current in vitro studies, we investigated the skin-protection properties of capsanthin 50%w/w crystals (CAP-50CR) and capsanthin 1.5% w/w soft extract (CAP-1.5SE) obtained from red bell pepper fruits, out of which one is an industrial by-product on sunburn, melanin inhibition, tyrosinase inhibition, anti-fungal activity and, gene expression of Aquaporin 3 (AQP-3) in the human keratinocyte cell line. Methodology: The two extracts, obtained by solvent extraction, super critical extract purification, saponification, characterized, and examined on their dermatological activities. Results: Capsanthin 50%w/w crystals (CAP-50CR) showed a sun protection factor (SPF) value of 34.44 whereas capsanthin 1.5% w/w soft extract (CAP-1.5SE) showed a value of 20.63. Minimal inhibitory concentration (MIC) of CAP-50CR against Malassezia furfur was 0.625 mg/mL and CAP-1.5SE showed a MIC of 5mg/mL. Both CAP-50CR and CAP-1.5SE showed the same MIC against Candida albicans which is 2.5 mg/mL. In the MTT assay on mouse skin melanoma cells (B16F10), the test substance CAP-50CR showed a CTC50 value of 98.44±2.55 µg/mL whereas the test substance CAP-1.5SE exhibited a CTC50 value greater than 1000 µg/mL. Further, the non-toxic concentrations of the test items were evaluated for forskolin-induced melanin inhibition activity. For CAP-50CR, the non-toxic concentration of 7 and 3 µg/mL showed the melanin inhibition of 48.73±0.75% and 42.29±5.2% and for CAP-1.5SE the melanin inhibition was found to be 55.84%±1.47 and 46.44%±1.05 for the non-toxic concentration of 50 and 25µg/mL. The CAP-50CR extract showed 43.78% and 39.37% tyrosinase inhibition at the tested concentrations of 7 and 3 µg/mL. Similarly, CAP-1.5SE showed the tyrosinase inhibitions as 34.6% and 22.9% for the concentrations of 50 and 25 µg/mL. The test substances CAP-50CR and CAP-1.5SE exhibited a CTC50 value of 76.59±3.25 μg/mL and 664.95±2.88 µg/mL on the HaCaT cells. In the gene expression study, both the test substances showed an increase in the levels of AQP-3 mRNAs at lower and higher concentrations as compared to the control in the semi-quantitative RT-PCR procedure. Conclusion: CAP-50CR and CAP-1.5SE showed skin protection from UV radiation and hyperpigmentation. Also exhibits anti-fungal, skin brightening, anti-wrinkle and moisturizing properties. These results suggests that capsanthin from red bell pepper fruit can be employed as cosmetic active ingredient in skin guard formulations and as a potential therapeutic agent for variety of dermatological disorders. This study breaks new ground by investigating the potential of capsanthin in the management of skin protection for the first time.

The preventive effect of loganin on oxidative stress-induced cellular damage in human keratinocyte HaCaT cells.

Loganin is a type of iridoid glycosides isolated from Corni fructus and is known to have various pharmacological properties, but studies on its antioxidant activity are still lacking. Therefore, in this study, the preventive effect of loganin on oxidative stress-mediated cellular damage in human keratinocyte HaCaT cells was investigated. Our results show that loganin pretreatment in a non-toxic concentration range significantly improved cell survival in hydrogen peroxide (H2O2)-treated HaCaT cells, which was associated with inhibition of cell cycle arrest at the G2/M phase and induction of apoptosis. H2O2-induced DNA damage and reactive oxygen species (ROS) generation were also greatly reduced in the presence of loganin. Moreover, H2O2 treatment enhanced the cytoplasmic release of cytochrome c, upregulation of the Bax/Bcl-2 ratio and degradation of cleavage of poly (ADP-ribose) polymerase, whereas loganin remarkably suppressed these changes. In addition, loganin obviously attenuated H2O2-induced autophagy while inhibiting the increased accumulation of autophagosome proteins, including as microtubule-associated protein 1 light chain 3-II and Beclin-1, and p62, an autophagy substrate protein, in H2O2-treated cells. In conclusion, our current results suggests that loganin could protect HaCaT keratinocytes from H2O2-induced cellular injury by inhibiting mitochondrial dysfunction, autophagy and apoptosis. This finding indicates the applicability of loganin in the prevention and treatment of skin diseases caused by oxidative damage.

Additive Interactions between Betulinic Acid and Two Taxanes in In Vitro Tests against Four Human Malignant Melanoma Cell Lines.

The incidence of melanoma is steadily increasing worldwide. Melanoma is the most lethal skin cancer, and new therapeutic methods are being sought. Our research aimed to investigate the cytotoxic and antiproliferative effects of betulinic acid in vitro, used alone and in combination with taxanes (paclitaxel, docetaxel) in four melanoma cell lines. Isobolographic analysis allowed us to assess the interactions between these compounds. Betulinic acid had no cytotoxic effect on normal human keratinocyte HaCaT cells; the amount of LDH released by them was significantly lower compared to melanoma cell lines. The present study shows that betulinic acid significantly inhibits the growth of melanoma cell lines in vitro. The IC50 values of betulinic acid ranged from 2.21 µM to 15.94 µM against the four melanoma lines. Co-treatment of betulinic acid with paclitaxel or docetaxel generated desirable drug–drug interactions, such as an additive and additive with a tendency to synergy interactions.

Fractions of Hoslundia opposita Vahl and hoslundin induced apoptosis in human cancer cells via mitochondrial-dependent reactive oxygen species (ROS) generation

BackgroundCancer remains one of the leading causalities of several morbidity and mortality with negative impact on global economy due to low workforce and management/treatment cost. A number of conventional therapies have been explored in the management/treatment of cancer including chemotherapeutic intervention, radiotherapy, and surgery. Among these treatment modalities, chemotherapy remains the most popular first line of intervention in management/treatment of cancer, and natural products have been implicated as the main source of antineoplastic agents with phenomenal efficacy. However, current antineoplastic agents suffer from lack of selectivity and specificity necessitating the need for further research in the search for novel anticancer drug molecules. MethodsIn this present study, the anticancer activity of Hoslundia opposita leaves extracts were tested against a number of cell lines including human hepatoma cell line (HepG2), human breast cancer cell lines (MDA-MB-231), intestinal epithelial cell lines (Caco-2), and human keratinocyte HACAT cell lines. A bio-guided fractionation assay and the structural elucidation of the pure isolate (hoslundin) was conducted by 1D and 2D NMR spectroscopy. The cell viability, colony formation, and apoptotic activities were investigated using MTT assay, clonogenic assay, and caspase − 3 and − 7 kits respectively. Flow cytometry was employed in assessing the altered cell cycle expression. The production of the intracellular reactive oxygen species (ROS) levels and the reduction of the mitochondrial membrane potential (MMP) was determined at the cellular level using fluorescent probe dyes dihydro-fluorescin diacetate (DCFH-DA) and tetramethylrhodamin (TMRE), respectively. ResultsThe H. opposita fractions and its pure isolate (hoslundin) demonstrated a potent cytocidal activity against the tumorigenic cells (HepG2, MDA-MB-231, Caco-2) at concentration ranging from 25 to 100 µg/mL. The inhibition of the colony formation was significantly observed in HepG2 cell lines. More so, the cellular viability of the normal cells (HaCaT) was relatively unchanged in the presence of H. opposita fractions and its isolate proving the selectivity of the compounds towards tumourigenic cells. The H. opposita fractions and hoslundin exerted their anticancer activity via cell cycle arrest with the accumulation of the DNA content at the S-phase, activation of apoptosis in the caspase 3,7 activities and depolarized mitochondrial membrane potential mediated by mitochondrial-dependent ROS generation in the treated tumor cells. ConclusionThe anticancer activities of Hoslundia opposita Vahl and hoslundin exhibited significant efficacy against tumor cells and well tolerated in the presence of normal cells making them a potential antineoplastic agent.

Aspirin Protects against UVB-Induced DNA Damage through Activation of AMP Kinase

The anti-inflammatory and chemopreventive activities of aspirin (ASA) may be mediated through its cyclooxygenase inhibitor function. We have previously shown that ASA can protect against UVR-induced skin inflammation and DNA damage; however, the role of inflammation in UV-induced DNA damage and the mechanism underlying ASA protection are poorly characterized. Using immunodeficient NOD scid gamma mice and immunocompetent C57BL/6 mice treated with immune cell‒depleting antibodies, we found that inflammation was not required for UVB-induced 8-oxoguanine and cyclobutane pyrimidine dimers invivo. Unlike ASA, neither its immediate metabolite salicylate nor the cyclooxygenase inhibitor indomethacin reduced UVB-induced 8-oxoguanine or cyclobutane pyrimidine dimers in melanocyte Melan-a or keratinocyte HaCat cells invitro. Moreover, addition of prostaglandin E2 did not reverse the protective effect of ASA on UVB-treated cells. Phosphorylation of the 5' AMP protein kinase, observed in ASA-treated cells, could be blocked by the 5' AMP protein kinase inhibitor compound C. Compound C or 5' AMP protein kinase knockdown partially reduced ASA-mediated protection against UVB-induced DNA damage. Finally, injection of compound C partially reversed the protective effect of ASA on UVB-treated mouse skin invivo. These studies suggest that ASA confers protection against UVB-induced DNA damage through the activation of 5' AMP protein kinase rather than through cyclooxygenase inhibition.

Sugar easters and xanthones from the roots of Polygala tenuifolia Willd. and their cytoprotective activity

Six new sugar esters (1–6), named tenuifolisides F-G (1–2) and tenuifolioses W-Z (3–6), together with 16 known compounds (7–22) were isolated from the roots of Polygala tenuifolia. The chemical structures of the new compounds were elucidated by 1D, 2D NMR and HRESIMS techniques together with chemical methods. All the compounds were evaluated for the cytoprotective activity against hydrogen peroxide (H2O2)-induced oxidative stress in human keratinocyte HaCaT cells. Compounds 4, 5, 13, 20 and 22 showed strong cytoprotective effect.

The role of human antigen R (HuR) in modulating proliferation, senescence and radiosensitivity of skin cells.

The skin is the largest outermost organ of the human body. It is vulnerable to various damages, such as ionizing radiation. Exploration of proliferation, senescence and radiosensitivity of skin cells contributes to the development of medical and cosmetic countermeasures against skin aging and toward injury protection. Human antigen R (HuR) is one of the most widely studied RNA-binding proteins and serves an important role in stabilization of mRNA and regulation of the expression of the target genes. To investigate the role of HuR in modulating proliferation, senescence and radiosensitivity of skin cells, the present study performed an in vitro study using lentivirus-mediated overexpression or silencing of HuR in human keratinocyte HaCaT cells and human skin fibroblast WS1 cells. The results indicated that overexpression of HuR promoted proliferation, whereas downregulation of HuR inhibited proliferation of HaCaT and WS1 cells. Overexpression of HuR reduced apoptosis and senescence in skin cells. RNA-Seq of skin cells with HuR overexpression or knockdown identified 77 mRNAs positively or negatively correlated with HuR expression levels. In addition, silencing of HuR induced a significant increase in radiogenic reactive oxygen species after irradiation. Overexpression of HuR increased radiotolerance of HaCaT and WS1 cells. RNA immunoprecipitation coupled with RNA-Seq identified 14 mRNAs interacting with HuR upon radiation exposure. Overall, the findings of the present study illustrated the key role of HuR in modulating proliferation, senescence and radiosensitivity of skin cells providing a new therapeutic strategy for cosmetic treatments and to combat skin injury.

Characterization of Gels and Films Produced from Pinhão Seed Coat Nanocellulose as a Potential Use for Wound Healing Dressings and Screening of Its Compounds towards Antitumour Effects.

The reuse of agro-industrial waste assumes great importance today. Pinhão is the seed of Araucaria angustifolia, which is native to the mountains of southern Brazil, Paraguay, and Argentina. The coat is a by-product of this seed and is rich in phenolic compounds. The present study aimed to use the residue as a precursor material for the production of nanocellulose through the mechanical defibrillation process and perform the characterization of the films and the gel to investigate the effect on the physical and regenerative properties when incorporated with polyvinyl alcohol (PVA). The modulus of elasticity was higher when the MFC of pinhão was added to the PVA. Film and gel had their cytotoxicity tested by MTT assay using 3T3 fibroblast and Schwann cancer cells, and a migration assay was also performed using the scratch test on HaCat keratinocyte cells. For the scratch test, film and gel samples with low concentration presented a complete scratch closure in 72 h. Molecular docking was performed and quercetin had the ideal interaction score values, so it was used with the PACAP protein which presented a slightly moderate interaction with the protein synthesis of Schwann cells, presenting compactness of the compound after 14 ns.

Fenofibrate Attenuates Radiation-Induced Oxidative Damage to the Skin through Fatty Acid Binding Protein 4 (FABP4).

Radiation facilities and radioactive materials have been widely used in military, industry, medicine, science and nuclear facilities, which has significantly increased the potential of large-scale, uncontrolled exposure to radiation. The skin is one of the radiosensitive organ systems and radiation-induced skin injury remains a serious concern after ionizing radiation exposure. Our previous report indicates the involvement of the peroxisome proliferator-activated receptor pathway in the response of skin tissues to ionizing radiation. PPARα is a member of the PPAR nuclear hormone receptor superfamily, which can be activated by fibrate ligands. However, the protection of fenofibrate against ionizing radiation in skin keratinocytes and fibroblasts has not been described. The PPARα mRNA levels in irradiated and nonirradiated skin tissues of rats were determined by real-time assay. The expression of PPARα, and FABP4 were evaluated by western blot and IHC assay. The cell proliferation was detected by colony formation. The γH2AX foci and ROS levels in irradiated WS1 cells with FABP4 overexpression than in control cells were performed by Immunofluorescence assay. We found that PPARα expression was lower in the irradiated skin tissues of mouse, rat, monkey, and human patients than in their nonirradiated counterparts. PPARα fenofibrate significantly decreased radiation-induced ROS and apoptosis in a dose-dependent manner in human keratinocyte HaCaT and skin fibroblast WS1 cells. Moreover, fenofibrate significantly decreased radiation-induced ROS and malondialdehyde (MDA) levels in electron beam irradiated skin tissues of rats. Mechanistically, the proximal promoter of fatty acid binding protein 4 (FABP4) harbored three binding sites of PPARα and fenofibrate stimulated the transcription of FABP4 in skin cells. FABP4 overexpression decreased radiation-induced ROS and γH2AX foci. FABP4 inhibitor BMS309403 abrogated the ROS-eliminating activity as well as the lipid-accumulating role of fenofibrate, indicating that FABP4 mediates the radioprotective role of fenofibrate. In addition, FABP4 overexpression significantly decreased radiation-induced oxidative damage in vivo. These results confirm that fenofibrate attenuated radiation-induced oxidative damage to the skin by stimulating FABP4.

잇꽃 에탄올 및 열수 추출물의 항노화 기반 항주름효과 비교

Background: The safflower flower (Carthamus tinctorius) contains many bioactive substances and natural pigments. This study aimed to develop a safe and effective functional cosmetic material by comparing the antioxidant and anti-wrinkle effects of C. tinctorius flower ethanol extract (CTE) and hot water extract (CTW).BRMethods and Results: First, the content of hydroxysafflor yellow A in CTE and CTW was determined. Subsequently, a cell-free system was used to examine the 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity of CTE and CTW. Furthermore, the effects of CTE and CTW on elastase and matrix metalloproteinase-1 (MMP-1) were determined through enzymatic analysis or real-time quantitative reverse transcription polymerase chain reaction (qRT-PCR) in human dermal fibroblast (HDF) cells. The wound closure effect of CTW was also measured using the scratching assay in keratinocyte HaCaT cells. The DPPH scavenging activity of CTE was slightly higher than that of CTW. Regarding wrinkle formation, CTE unexpectedly increased MMP-1 and had no effect on elastase activity except at 1,000 ㎍/㎖ of CTE. In contrast, CTW inhibited both elastase activity and MMP-1 expression. CTW also showed a considerable increase in wound closure rate in the scratching assay.BRConclusions: In conclusion, CTW containing the natural pigment hydroxysafflor yellow A is an effective substance for wrinkle treatment and wound healing for skin aging.

Synthesis, In Vitro, and Computational Studies of PTP1B Phosphatase Inhibitors Based on Oxovanadium(IV) and Dioxovanadium(V) Complexes.

One of the main goals of recent bioinorganic chemistry studies has been to design and synthesize novel substances to treat human diseases. The promising compounds are metal-based and metal ion binding components such as vanadium-based compounds. The potential anticancer action of vanadium-based compounds is one of area of investigation in this field. In this study, we present five oxovanadium(IV) and dioxovanadium(V) complexes as potential PTP1B inhibitors with anticancer activity against the MCF-7 breast cancer cell line, the triple negative MDA-MB-231 breast cancer cell line, and the human keratinocyte HaCaT cell line. We observed that all tested compounds were effective inhibitors of PTP1B, which correlates with anticancer activity. [VO(dipic)(dmbipy)]·2 H2O (Compound 4) and [VOO(dipic)](2-phepyH)·H2O (Compound 5) possessed the greatest inhibitory effect, with IC50 185.4 ± 9.8 and 167.2 ± 8.0 nM, respectively. To obtain a better understanding of the relationship between the structure of the examined compounds and their activity, we performed a computer simulation of their binding inside the active site of PTP1B. We observed a stronger binding of complexes containing dipicolinic acid with PTP1B. Based on our simulations, we suggested that the studied complexes exert their activity by stabilizing the WPD-loop in an open position and limiting access to the P-loop.

Antioxidative Properties of Plant-Based Protein Isolates: NUTRALYS® Pea Protein

ObjectivesAntioxidants display protective benefits both in food and pharmaceutical products against oxidative deterioration and in the body against pathologies brought by oxidative stress. Proteins can contain peptides sequences with potential antioxidant bioactivities. As plant-based proteins sources are more and more consumed, the screening of their antioxidant properties is of great interest to provide new alternative solutions in place of synthetic antioxidants and to meet enhanced public awareness about health issues. Various in vitro methods are validated for screening and some have been used here to qualify the antioxidative potential of NUTRALYS® pea protein range (Roquette). MethodsTwo grades of pea protein isolates, NUTRALYS® S85F and NUTRALYS® S85 Plus, were screened before or after in vitro gastro-intestinal digestion (IVD) for their antioxidant activity with different methods: 1/reactive oxygen species (ROS) adapted scavenging assays (acellular) (Haliwell et al., 1987; Aruoma et al., 1989) to determine their ability to inhibit the productions of O2.-, H2O2 and HO. radicals; 2/AOP1 (LUCS) technology (Gironde et al., 2020), evaluating on human keratinocytes (HaCat cells) the ROS scavenging potential by the kinetic evolution of a fluorescence emission; 3/Nrf2 technology (Furger, 2021) measuring on HaCat cells the ability to activate the ARE/Nrf2 gene pathway, responsible for natural antioxidant cell defense (cytoprotective effect), by oxyluciferin luminescent detection. ResultsNUTRALYS® S85F and S85 Plus demonstrated significant scavenging activities towards HO. and H2O2 (before and after IVD) and NUTRALYS® S85F towards O2.- (before IVD), with all IC50 far below 5 mg.mL–1 (Dugardin et al., 2020). No significant direct antioxidant effect (LUCS) was observed with NUTRALYS® S85 Plus digests, but significant activation of the ARE/Nrf2 gene pathway (EC50 = 1.39 mg.mL-1 dry matter), indicating a potential induction of cell anticipation towards putative radical aggression, and a long-term effect. ConclusionsNUTRALYS® S85F and NUTRALYS® S85 Plus exhibit intrinsic antioxidative properties, often conserved after IVD, as observed through various methods. Based on these results, NUTRALYS® S85F and NUTRALYS® S85 Plus may therefore provide oxidative stability to food products and health benefits to the consumer. Funding SourcesRoquette.

Modulating effects of oral administration of Lycii Fructus extracts on UVB-induced skin erythema: A Randomized, placebo-controlled study.

Severe UV exposure induces skin inflammation, causing erythema. Lycii Fructus (Lycium barbarum and Lycium chinense) is a potential antioxidant agent with a high content of polyphenols, including rutin and chlorogenic acid. This study examined the effects of Lycii Fructus extract (LFE) on UVB-induced skin erythema in humans. Healthy volunteers were randomly assigned to one of two groups and received UVB irradiation at 1.5 minimal erythemal dose (MED) on day 0 at three designated sites on their backs, and the skin color was measured until day 7. After an 8-week treatment with LFE (900 mg/day) or placebo, UVB irradiation (l.5 MED) was applied again at different sites on day 63. Skin color was continuously measured in each group until day 69. LFE tablet administration for 8 weeks significantly inhibited UVB-induced erythema formation and increased the MED by 13%. Erythema formation peaked on the first day after UVB irradiation, but gradually dissipated over the next several days. LFE tended to accelerate erythema disappearance. To determine the polyphenol responsible for the protection against UVB-induced skin damage, the effects of LFE-derived polyphenols and their metabolites on UVB-induced cytotoxicity were examined in vitro. The major intestinal metabolite of rutin and LFE significantly attenuated phototoxicity and in human keratinocyte HaCaT cells. Quercetin enhanced intracellular glutathione levels in HaCaT cells, even though LFE did not increase it. Together, the results showed that LFE inhibited erythema formation and accelerated erythema dissipation, possibly through its direct antioxidative action.

Synthesis of AC1903 analogs as potent transient receptor potential canonical channel 4/5 inhibitors and biological evaluation

Transient receptor potential canonical (TRPC) channels are a class of non-selective cation channels expressed in a variety of tissues and organ systems where they functionally regulate physiological and pathological processes. TRPC5 has been shown to be a promising target for focal segmental glomerulosclerosis treatment. In this study, we report the synthesis and biological evaluation of a novel series of benzimidazole-based TRPC5 inhibitors. One compound, 8b, is 100-fold more potent than the parent compound, AC1903, in the suppression of TRPC5 channel activity. Interestingly, both AC1903 and 8b also suppressed TRPC4 channel activity with similar potency. Compound 8b also significantly blunts protamine sulfate-induced reorganization of podocyte cytoskeleton, interleukin (IL)-17-induced cell proliferation, and the expression of proinflammatory mediators in human keratinocyte HaCaT cells.

Prophylactic Effect of Nitric Oxide Donors on Rat Models of EGFR Inhibitor‒Induced Cutaneous Toxicities

EGF receptor (EGFR) inhibitors have been established as first-line standard-of-care therapies for nonsmall cell lung cancer but are frequently accompanied by adverse dermatological effects, in particular, acneiform rash. There is no effective clinical intervention, partially because of its poorly understood etiology. In this study, we show that inhibition of EGFR initiated keratinocyte HaCaT cell cycle arrest and apoptosis, which fueled a robust secondary inflammatory response. Rats gavaged with EGFR inhibitor showed a phenotype similar to that of clinical patients, which was in line with the interrupted functions observed in HaCaT keratinocytes. We found that a nitric oxide donor, nitroglycerin, was a feasible treatment alternative for EGFR inhibitor‒induced rash. Restoration of epidermal extracellular signal‒regulated kinase and a reduction in signal transducer and activator of transcription 3 signaling through nitroglycerin treatment rescued the cellular functions that had been damaged invitro and further ameliorated the rash in rat models. In addition, the efficacy of nitroglycerin was superior to that of existing clinical interventions. These data highlighted the importance of epidermal EGFR signaling and led to the identification of a small-molecule nitric oxide donor as a mediator that can maintain EGFR pathway functions during anti-EGFR therapies, providing a therapeutic anchor point for adverse EGFRI-induced skin effects.

Non-covalent small molecule partnership for redox-active films: Beyond polydopamine technology

HypothesisThe possibility to use hexamethylenediamine (HMDA) to impart film forming ability to natural polymers including eumelanins and plant polyphenols endowed with biological activity and functional properties has been recently explored with the aim to broaden the potential of polydopamine (PDA)-based films overcoming their inherent limitations. 5,6-dihydroxyindole-2-carboxylic acid, its methyl ester (MeDHICA) and eumelanins thereof were shown to exhibit potent reducing activity. ExperimentsMeDHICA and HMDA were reacted in aqueous buffer, pH 9.0 in the presence of different substrates to assess the film forming ability. The effect of different reaction parameters (pH, diamine chain length) on film formation was investigated. Voltammetric and AFM /SEM methods were applied for analysis of the film redox activity and morphology. HPLC, MALDI-MS and 1HNMR were used for chemical characterization. The film reducing activity was evaluated in comparison with PDA by chemical assays and using UV stressed human immortalized keratinocytes (HaCat) cells model. FindingsRegular and homogeneous yellowish films were obtained with moderately hydrophobic properties. Film deposition was optimal at pH 9, and specifically induced by HMDA. The film consisted of HMDA and monomeric MeDHICA accompanied by dimers/small oligomers, but no detectable MeDHICA/HMDA covalent conjugation products. Spontaneous assembly of self-organized networks held together mainly by electrostatic interactions of MeDHICA in the anion form and HMDA as the dication is proposed as film deposition mechanism. The film displayed potent reducing properties and exerted significant protective effects from oxidative stress on HaCaT.