High molecular weight hyaluronic acid vectorised with clay provides long-term hydration and reduces skin brightness.

BACKGROUND: Hyaluronic acid (HA) is a widely used active cosmetic ingredient. Its multiple skin care benefits are modulated by its molecular weight. Low molecular weight (LMW) HA can penetrate the skin, but high molecular weight (HMW) HA remains at the surface. Here, we assessed how vectorization of HMW HA with bentonite clay-achieved with an innovative technology-enhances its cosmetic and hydrating properties. MATERIALS AND METHODS: The two HA forms were applied to skin explants; their penetration and smoothing effects were monitored by Raman spectroscopy and scanning electron microscopy. The two forms were biochemically characterised by chromatography, enzyme sensitivity assays, and analysis of Zeta potential. Cosmetics benefits such as, the smoothing effect of vectorised-HA was assessed in ex vivo experiments on skin explants. A placebo-controlled clinical study was finally conducted applying treatments for 28 days to analyse the final benefits in crow's feet area. RESULTS: Raman spectroscopy analysis revealed native HMW HA to accumulate at the surface of skin explants, whereas vectorised HMW HA was detected in deeper skin layers. This innovative vectorisation process changed the zeta potential of vectorised HMW HA, being then more anionic and negative without impacting the biochemical structure of native HA. In terms of cosmetic benefits, following application of vectorised HMW HA ex vivo, the skin's surface was visibly smoother. This smoothing was clinically confirmed, with a significant reduction in fine lines. CONCLUSION: The development of innovative process vectorising HMW HA allowed HMW HA penetration in the skin. This enhanced penetration extends the clinical benefits of this iconic cosmetic ingredient.

A highly soluble form of rutin for instant resolution of mask-wearing related disorders.

BACKGROUND: The COVID-19 pandemic brought about a new normal, necessitating the use of personal protective equipment (PPE) like face shields, surgical masks, gloves, and goggles. However, prolonged mask-wearing introduced skin-related issues due to changes in the skin's microenvironment, including increased humidity and temperature, as well as pressure on the skin. These factors led to skin deformation, vascular issues, edema, and inflammation, resulting in discomfort and cosmetic concerns. Clinical reports quickly highlighted the consequences of long-term mask use, including increased cases of "maskne" (mask-related acne) or mask-wearing related disorders such as rosacea flare-ups, skin-barrier defects, itching, erythema, redness, hyperpigmentation, and lichenification. Some of these issues, like inflammation, oxidative stress, and poor wound healing, could be directly linked to acne-related disorders or skin hypoxia. AIM: To address these problems, researchers turned to rutin, a well-known flavonoid with antioxidant, vasoactive, and anti-inflammatory properties. However, rutin's poor water solubility presented a challenge for cosmetic formulations. To overcome this limitation, a highly water-soluble form of rutin was developed, making it suitable for use at higher concentrations. METHODS: In vitro and ex vivo tests were conducted, as well as an innovative clinical trial including volunteers wearing surgical masks for at least 2 h, to evaluate the biological activity of this soluble rutin on the main skin concerns associated with mask-wearing (inflammation, oxidative stress, skin repair, hyperpigmentation, and skin redness). RESULTS: The in vitro results showed that the active ingredient significantly reduced oxidative stress, improved wound healing, and reduced inflammation. In dark skin explants, the active ingredient significantly reduced melanin content, indicating its lightening activity. This effect was confirmed in the clinical study, where brown spots decreased significantly after 4 days of application. Moreover, measurements on volunteers demonstrated a decrease in skin redness and vascularization after the active ingredient application, indicating inflammation and erythema reduction. Volunteers reported improved skin comfort. CONCLUSION: In summary, the COVID-19 pandemic led to various skin issues associated with mask-wearing. A highly soluble form of rutin was developed, which effectively addressed these concerns by reducing inflammation, oxidative stress, and hyperpigmentation while promoting wound healing. This soluble rutin offers a promising solution for the rapid treatment of maskne-related disorders and other skin problems caused by prolonged mask use.

Skin Cellular Reprogramming as an Innovative Anti-Aging Strategy for Cosmetic Application: A Clinical Study of Sericoside.

BACKGROUND: While our body ages, skin cells progressively lose their pluripotency and proliferative capacities, as well as remodeling driver role, among other activities. This loss of capacities leads to visible aging signs such as wrinkles, under-eye bags or even aging spots. We studied if the stimulation of cell pluripotency and proliferation by a natural molecule could be an innovative anti-ageing strategy for skin rejuvenation. METHODS: The activity of sericoside, a compound extracted from the bark of Terminalia sericea roots, was evaluated at a concentration of 0.02% in vitro. This assessment involved transcriptomic analysis on fibroblasts after 24 hours, as well as proliferation tests on aged fibroblasts after 72 hours. A clinical study was then conducted on 40 volunteers between the ages of 35 and 55. For four weeks, volunteers applied a cream twice daily containing either sericoside or blank emulsion (control group). Skin elasticity was measured by cutometry with R2 parameter. Skin texture and roughness was analyzed by an in vivo 3D scanner. RESULTS: Transcriptomic analysis showed that sericoside improved the set of gene expressions involved in cell cycle (+85% MKI67), cell proliferation (+250% IGF1), DNA repair (+56% OGG1), pluripotency transcription factors (+36% NANOG) and stem cells maintenance (+200% SOX2). We substantiated a decrease of proliferation factor with aged cells compared to young cells by 50%, while sericoside increased this proliferation factor by +46%, a similar rate to that of a 22-year-old donor. Clinically, the anti-aging effects of sericoside were evident: the use of sericoside resulted in a 17% increase in skin elasticity and a 10% reduction in skin roughness, underscoring the smoothing effect with sericoside. CONCLUSIONS: The study highlighted an innovative anti-aging strategy that involves re-activating cells' memory to reprogram cell pluripotency by stimulating the natural tools available in our DNA.

Gardenia jasminoides Extract, with a Melatonin-like Activity, Protects against Digital Stress and Reverses Signs of Aging.

Digital stress is a newly identified cosmetic stress that is mainly characterized by blue light exposure. The effects of this stress have become increasingly important with the emergence of personal digital devices, and its deleterious effects on the body are now well-known. Blue light has been observed to cause perturbation of the natural melatonin cycle and skin damage similar to that from UVA exposure, thus leading to premature aging. "A melatonin-like ingredient" was discovered in the extract of Gardenia jasminoides, which acts as a filter against blue light and as a melatonin-like ingredient to prevent and stop premature aging. The extract showed significant protective effects on the mitochondrial network of primary fibroblasts, a significant decrease of -86% in oxidized proteins on skin explants, and preservation of the natural melatonin cycle in the co-cultures of sensory neurons and keratinocytes. Upon analysis using in silico methods, only the crocetin form, released through skin microbiota activation, was found to act as a melatonin-like molecule by interacting with the MT1-receptor, thus confirming its melatonin-like properties. Finally, clinical studies revealed a significant decrease in wrinkle number of -21% in comparison to the placebo. The extract showed strong protection against blue light damage and the prevention of premature aging through its melatonin-like properties.

Targeting SDF-1 as an efficient strategy to resolve skin hyperpigmentation issues with Himanthalia elongata extract.

BACKGROUND: During aging, human skin is facing hyperpigmentation disorders: senile lentigo (chronobiologic aging) leads to loss of melanogenesis' control while solar lentigo (UV exposure) promotes an increase of oxidized proteins, melanogenesis, and lipofuscin. AIMS: Stromal-cell-derived-factor-1 (SDF-1) was identified as key regulator of hyperpigmentation and its expression is reduced in senescent fibroblasts, highlighting this protein as new target for skin hyperpigmentation. MATERIALS: We developed two skin explant models mimicking of senile and solar lentigo, based on H2 O2 systemic treatment and UV irradiation, respectively. We evaluated Himanthalia elongata extract (HEX) on these models after 5 days of treatment and analyzed SDF-1 expression and skin pigmentation. For solar lentigo, we also analyzed oxidized proteins and lipofuscin accumulation. Finally, we evaluated HEX in vivo on nearly 100 multi ethnicities' volunteers. RESULTS: SDF-1 expression decreased in senile lentigo model, associated with hyperpigmentation. HEX application restored SDF-1 expression, leading to skin pigmentation decrease. For solar lentigo, we showed an impact of UVs on SDF-1 expression linked to hyperpigmentation, while the application of HEX restored SDF-1 expression and reduced skin pigmentation. On same model, HEX reduced oxidized proteins quantity and lipofuscin which increased after UV exposure. Clinically, HEX reduced dark spot pigmentation on Caucasian volunteers' hands and on Asian and African volunteers' face after 28 days. DISCUSSION: We have developed ex vivo models mimetic of senile and solar lentigo and showed for a very first time that SDF-1 can be also a key regulator for UV-induced hyperpigmentation. CONCLUSION: Our ex vivo and clinical studies highlighted the power of HEX with strong reduction of dark spots regardless of volunteers' ethnicities.

Action of Mangifera indica Leaf Extract on Acne-Prone Skin through Sebum Harmonization and Targeting C. acnes.

(1) Background: Preclinical studies report that the ethanolic fraction from Mangifera indica leaves is a potential anti-acne agent. Nevertheless, the biological activity of Mangifera indica leaves has scarcely been investigated, and additional data are needed, especially in a clinical setting, for establishing the actual effectiveness of Mangifera indica extract as an active component of anti-acne therapy. (2) Methods: The evaluation of the biological activity of Mangifera indica extract was carried out through different experimental phases, which comprised in silico, in vitro, ex vivo and clinical evaluations. (3) Results: In silico and in vitro studies allowed us to identify the phytomarkers carrying the activity of seboregulation and acne management. Results showed that Mangifera indica extract reduced lipid production by 40% in sebocytes, and an improvement of the sebum quality was reported after the treatment in analyses performed on sebaceous glands from skin explants. The evaluation of the sebum quantity and quality using triglyceride/free fatty acid analysis conducted on Caucasian volunteers evidenced a strong improvement and a reduction of porphyrins expression. The C. acnes lipase activity from a severe acne phylotype was evaluated in the presence of Mangifera indica, and a reduction by 29% was reported. In addition, the analysis of the skin microbiota documented that Mangifera indica protected the microbiota equilibrium while the placebo induced dysbiosis. (4) Conclusions: Our results showed that Mangifera indica is microbiota friendly and efficient against lipase activity of C. acnes and supports a role for Mangifera indica in the therapeutic strategy for prevention and treatment of acne.

Bacterial taxa predictive of hyperpigmented skins.

Background and Aims: Dark spots, brown spots, or hyperpigmented spots (HPS) are oval or irregular brown areas of skin. Their emergence is associated with dysregulation of the immune system, and may also be caused by a deficiency in stromal cell-derived factor-1, leading to perturbed melanogenesis and accumulation of melanosomes within neighboring keratinocytes. The skin microbiota (living microorganisms present on the surface of the skin) is known to play essential roles in maintaining skin homeostasis and in regulating the immune system. Here, we investigated whether the microbiota could play a role in the emergence of HPS. Methods: The clinical study involved 38 European women, selected from among 74 volunteers. Participants were divided into two groups depending on the spot areas measured on their faces. The study was designed to avoid conflicting factors: both groups presented similar skin pH, hydration, transepidermal water loss, and sebum levels. The two cohorts were also age-matched, with a mean of 29-years-old for both. Results: Alpha-diversity of the microbiota was similar for the two groups. On skins with more HPS, seven bacterial genera were identified in significantly higher proportions and included opportunistic pathogens and inflammatory bacteria. Six bacterial genera, including bacteria showing antioxidant and anti-UV properties, were identified in significantly higher proportions on less spotted skins. Cross-domain association networks revealed distinct co-occurrences of genera between the two groups, suggesting nonidentical community structures and exchanges, depending on the HPS status. Conclusion: Our results reveal specific microbiota composition and networks on skins based on HPS status. Changes could alter communication with the immune system, leading to the emergence of dark spots. As an essential part of the overall skin ecosystem, and through its interaction with the skin matrix, the skin microbiota and its maintenance could be considered a new target for skincare applications.

The anti-wrinkles properties of sodium acetylated hyaluronate.

BACKGROUND: Intrinsic aging promotes wrinkles formation by an imbalance between matrix synthesis/degradation in favor of degradation. This is accelerated by the exposome leading to overproduction of protease and fewer remodeling. OBJECTIVE: Protecting the integrity of extracellular matrix appears as the most efficient anti-aging solution. We developed a grafted HA specifically designed to get anti-aging property due to a specific molecular weight and acetylation degree. METHODS: A transcriptomic analysis was performed on fibroblasts, followed by a measurement of MMP secretion and subsequent effect on collagen degradation. MMP expression in skin explants concerned by chronobiological and extrinsic aging was analyzed by immunostaining. A clinical study was conducted on volunteers presenting wrinkles on face to evaluate flash reduction of wrinkles after 6 h of application by profilometry and anti-aging efficacy after 2 months by VISIA® CR2.3. RESULTS: Transcriptomic analysis evidenced an inhibition of MMP gene expression with acetylated HA, confirmed by an inhibition of MMPs release by fibroblasts, and a protection of type I collagen against degradation. We confirmed the reduction of MMPs in mature skin and in skin explants exposed to UV and urban dust. We demonstrated during clinical studies the flash reduction effect of acetylated HA on crow's feet wrinkles and a filling of nasogenian areas 6 h after application, and a wrinkles number reduction on nasogenian area up to 2 months of application. CONCLUSION: We developed a new grafted HA owing protective properties against ECM degradation induced by chronobiological and extrinsic aging, leading to a significant and efficient anti-wrinkles effect.

Combining Raman imaging and MCR-ALS analysis for monitoring retinol permeation in human skin.

BACKGROUND: Monitoring the transcutaneous permeation of exogenous molecules using conventional techniques generally requires long pre-analytical preparation or labelling of samples. However, Raman spectroscopy is a label-free and non-destructive method which provides spatial distribution of tracked actives in skin. The aim of our study was to prove the interest of Raman imaging coupled with multivariate curve resolution alternating least square (MCR-ALS) analysis in monitoring retinol penetration into frozen and living human skin. MATERIALS AND METHODS: After topical treatment of skin samples by free or encapsulated retinol, thin cross sections were analysed by Raman imaging (up to 100 µm depth). Mann-Whitney test was used to identify retinol spectroscopic markers in skin. MCR-ALS was used to estimate retinol contribution in Raman spectral images. Heat maps were constructed to compare the distribution of free and encapsulated retinol in skin models. RESULTS: We identified the bands at 1158, 1196 and 1591 cm-1 as specific features for monitoring retinol in skin. Moreover, our MCR-ALS results showed an improvement of retinol penetration (up to 30 µm depth) with the encapsulated form as well as storage reservoir formation in stratum corneum, for each skin model. Finally, greater retinol penetration into living skin was observed. CONCLUSION: This study shows a proof of concept for the evaluation of retinol penetration in skin using Raman imaging coupled with MCR-ALS. This concept needs to be validated on more subjects to include inter-individual variability but also other factors affecting skin permeation (age, sex, pH, etc). Our study can be extended to other actives.

Mannose-6-phosphate complex and improvement in biomechanical properties of the skin.

BACKGROUND: The dermis is composed of a tangle of macromolecules that provides the skin its biomechanical properties. During chronological aging, fibroblasts lose their ability to synthesize collagen and an accumulation of matrix metalloproteinases leads to an increase in collagen degradation. As a result, there is a decline in the biomechanical properties of the skin. Skin aging is accelerated by external factors such as UV radiation and pollution, which induce accumulation of oxidants, and so of oxidized proteins in the skin. AIMS: Atomic force microscopy (AFM) has emerged as an alternative method for studying the biomechanical properties of skin cells and tissues. METHODS/RESULTS: Thus, we identified mannose-6-phosphate complex as a new powerful molecule capable of reversing the visible signs of aging by reorganizing the collagen network of the dermis and by improving the skin biomechanical properties. This effect was correlated with clinical studies that showed a marked antiaging effect through a reduction in the number of crow's feet and in the depth and size of neck wrinkles. CONCLUSION: Mannose-6-phosphate complex appeared to be able to protect proteins in the dermis scaffold against oxidation and degradation, allowing an improvement in the skin biomechanical properties.

Overall renewal of skin lipids with Vetiver extract for a complete anti-ageing strategy.

OBJECTIVE: Skin lipids are essential in every compartment of the skin where they play a key role in various biological functions. Interestingly, their role is central in the maintenance of hydration which is related to skin barrier function and in the skin structure through adipose tissue. It is well described today that skin lipids are affected by ageing giving skin sagging, wrinkles and dryness. Thereby, developing cosmetic actives able to reactivate skin lipids would be an efficient ant-ageing strategy. Due to the strong commitment of our scientists to innovate responsibly and create value, they designed a high value active ingredient named here as Vetiver extract, using a ground-breaking upcycling approach. We evidenced that this unique extract was able to reactivate globally the skin lipids production, bringing skin hydration and plumping effect for mature skin. METHOD: In order to demonstrate the global renewal of lipids, we evaluated the lipids synthesis on cutaneous cells that produce lipids such as keratinocytes, sebocytes and adipocytes then on Reconstructed Human Epidermis and skin explants. We evaluated the expression of proteins involved in ceramides transport and barrier cornification. We then evaluated hydration and sebaceous parameters on a panel of mature volunteers. RESULTS: We firstly demonstrated that Vetiver extract induced sebum production from human sebocytes cells lines but also improved its quality as observed by the production of specific antimicrobial lipids. Secondly, we demonstrated that Vetiver extract was able to restore skin barrier with the increase of skin lipids neosynthesis on Reconstructed Human Epidermis and skin explants. We also evidenced that Vetiver extract stimulated the lipids transport and epidermal cornification. Finally, Vetiver extract showed a significant effect on adipogenesis and maturation of adipocytes at in vitro and ex vivo models. We confirmed all these activities by showing that Vetiver extract improved sebum production and brought hydration through an increase of lipids content and their conformation. Vetiver extract induced an improvement of skin fatigue and a plumping effect by acting deeply on adipose tissue. CONCLUSION: In conclusion, we developed an active ingredient able to bring anti-ageing effect for mature skin by a global increase of skin lipids.

OBJECTIF: Les lipides de la peau sont essentiels dans chaque compartiment de la peau où ils jouent un rôle clé dans diverses fonctions biologiques. Il est intéressant de noter que leur rôle est central dans le maintien de l'hydratation, liée à la fonction de barrière cutanée, mais aussi dans la structure même de la peau, par le biais du tissu adipeux. Il est bien décrit aujourd'hui que les lipides de la peau sont affectés par le vieillissement, ce qui entraîne un relâchement de la peau, des rides et une sécheresse. Ainsi, le développement d'actifs cosmétiques capables de réactiver les lipides de la peau serait une stratégie efficace de lutte contre le vieillissement. En raison de l'engagement fort de nos scientifiques à innover de manière responsable et à créer de la valeur, ils ont conçus un ingrédient actif à forte valeur ajoutée, appelé ici extrait de Vétiver, en utilisant une approche révolutionnaire de « up-cycling ¼. Nous avons démontré que cet extrait unique était capable de réactiver globalement la production de lipides de la peau, apportant une hydratation de la peau et un effet repulpant pour les peaux matures. MÉTHODES: Afin de démontrer le renouvellement global des lipides, nous avons évalué la synthèse des lipides sur les cellules cutanées qui produisent des lipides tels que les kératinocytes, les sébocytes et les adipocytes, puis sur un modèle d'Epiderme Humain Reconstruit et les explants de peau. Nous avons évalué l'expression des protéines impliquées dans le transport des céramides et la kératinisation de la barrière cutanée. Nous avons ensuite évalué l'hydratation et les paramètres sébacés sur un panel de volontaires matures. RÉSULTATS: Nous avons tout d'abord démontré que l'extrait de Vétiver induit la production de sébum à partir de lignées cellulaires de sébocytes humains mais améliore également sa qualité comme l'indique la production de lipides antimicrobiens spécifiques. Ensuite, nous avons démontré que l'extrait de Vétiver était capable de restaurer la barrière cutanée grâce à l'augmentation de la néosynthèse lipidique sur un modèle d'Epiderme Humain Reconstruit et sur des explants de peau. Nous avons également démontré que l'extrait de Vétiver stimulait le transport des lipides et la kératinisation de l'épiderme. Enfin, l'extrait de Vétiver a montré un effet significatif sur l'adipogenèse et la maturation des adipocytes dans des modèles in vitro et ex vivo. Nous avons confirmé à l'échelle clinique toutes ces activités en montrant que l'extrait de Vétiver améliorait la production de sébum et apportait une hydratation grâce à une augmentation de la teneur en lipides ainsi qu'une modification de leur conformation. L'extrait de Vétiver a induit une amélioration de la fatigue cutanée et un effet repulpant en agissant en profondeur sur le tissu adipeux. CONCLUSION: En conclusion, nous avons développé un ingrédient actif capable d'apporter un effet anti-âge aux peaux matures par une augmentation globale des lipides de la peau.

Well-aging: A new strategy for skin homeostasis under multi-stressed conditions.

BACKGROUND: Several studies evidenced significant increase of cortisol is the consequence of UV or emotional stress and leads to various deleterious effects in the skin. AIM: The well-aging, a new concept of lifestyle, procures an alternative to the anti-aging strategy. We demonstrated that Tephrosia purpurea extract is able to stimulate well-being hormones while reducing cortisol release. Furthermore, we hypothesized that the extract could positively influence the global skin homeostasis. METHOD: We evaluated the impact of the extract on cortisol, ß-endorphin, and dopamine, released by normal human epidermal keratinocytes (NHEKs). A gene expression study was realized on NHEKs and NHDFs. The protein over-expression of HMOX1 and NQO1 was evidenced at cellular and tissue level. Finally, we conducted a clinical study on 21 women living in a polluted environment in order to observe the impact of the active on global skin improvement. RESULTS: The extract is able to reduce significantly the cortisol release while inducing the production of ß-endorphin and dopamine. The gene expression study revealed that Tephrosia purpurea extract up-regulated the genes involved in antioxidant response and skin renewal. Moreover, the induction of HMOX and NQO1 expression was confirmed on NHDFs, NHEKs and in RHE. We clinically demonstrated that the extract improved significantly the skin by reducing dark circles, represented by an improvement of L*, a*, and ITA parameters. CONCLUSION: Tephrosia purpurea extract has beneficial effects on skin homeostasis through control of the well-being state and antioxidant defenses leading to an improvement of dark circles, a clinical features particularly impacted by emotional and environmental stress.

From stem cells protection to skin microbiota balance: Orobanche rapum extract, a new natural strategy.

BACKGROUND: Healthy skin is a delicate balance between skin renewal and microbiota homeostasis, and its imbalance promotes premature aging and dermatological disorders. Skin stem cells are key actors in this process but their sensitivity to aging and external stressors such as UV reduces the skin renewal power. The skin microbiota has been recently described as active in the healthy skin, and its imbalance could trigger some disorders. AIMS: We hypothesized that reactivation of stem cells and maintenance of microbiota could be a disruptive strategy for younger and healthier skin. We thus developed a new plant extract that restores the entire skin renewal process by sequential activation from stem cells stimulation to microbiota protection. METHODS: We studied stem cells comportment in the presence of Orobanche rapum extract by survivin immunocytochemistry and caspases 3 and 9 dosages. We also analyzed epidermal differentiation markers by immunohistochemistry and lipids organization by GC/MS At the clinical level, we investigated the impact of O. rapum extract on microbiota and on skin aspect. RESULTS: We demonstrated an active protection of skin stem cells through the maintenance of their clone-forming capacity and resistance to UV through the overexpression of survivin coupled to caspases inhibition. Furthermore, we showed the restoration of epidermal differentiation markers and ceramide biosynthesis favorable to orthorhombic organization. Clinical studies, including microbiota analysis, showed an active skin surface renewal coupled with microbiota protection. CONCLUSION: We evidenced that our active ingredient is able to stimulate skin rejuvenation while protecting the cutaneous microbiota, creating healthier skin and thereby beauty.

GABA and GABA-Alanine from the Red Microalgae Rhodosorus marinus Exhibit a Significant Neuro-Soothing Activity through Inhibition of Neuro-Inflammation Mediators and Positive Regulation of TRPV1-Related Skin Sensitization.

The aim of the present study was to investigate the neuro-soothing activity of a water-soluble hydrolysate obtained from the red microalgae Rhodosorus marinus Geitler (Stylonemataceae). Transcriptomic analysis performed on ≈100 genes related to skin biological functions firstly revealed that the crude Rhodosorus marinus extract was able to significantly negatively modulate specific genes involved in pro-inflammation (interleukin 1α encoding gene, IL1A) and pain detection related to tissue inflammation (nerve growth factor NGF and its receptor NGFR). An in vitro model of normal human keratinocytes was then used to evaluate the ability of the Rhodosorus marinus extract to control the release of neuro-inflammation mediators under phorbol myristate acetate (PMA)-induced inflammatory conditions. The extract incorporated at 1% and 3% significantly inhibited the release of IL-1α and NGF secretion. These results were confirmed in a co-culture system of reconstructed human epithelium and normal human epidermal keratinocytes on which a cream formulated with the Rhodosorus marinus extract at 1% and 3% was topically applied after systemic induction of neuro-inflammation. Finally, an in vitro model of normal human astrocytes was developed for the evaluation of transient receptor potential vanilloid 1 (TRPV1) receptor modulation, mimicking pain sensing related to neuro-inflammation as observed in sensitive skins. Treatment with the Rhodosorus marinus extract at 1% and 3% significantly decreased PMA-mediated TRPV1 over-expression. In parallel with these biological experiments, the crude Rhodosorus marinus extract was fractionated by centrifugal partition chromatography (CPC) and chemically profiled by a recently developed 13C NMR-based dereplication method. The CPC-generated fractions as well as pure metabolites were tested again in vitro in an attempt to identify the biologically active constituents involved in the neuro-soothing activity of the Rhodosorus marinus extract. Two active molecules, namely, γ-aminobutyric acid (GABA) and its structural derivative GABA-alanine, demonstrated a strong capacity to positively regulate skin sensitization mechanisms related to the TRPV1 receptors under PMA-induced inflammatory conditions, therefore providing interesting perspectives for the treatment of sensitive skins, atopia, dermatitis, or psoriasis.

Zebiriosides A-L, oleanane saponins from the roots of Dendrobangia boliviana.

Twelve oleanane saponins, zebiriosides A-L, were isolated from the roots of Dendrobangia boliviana Rusby, together with two known saponins, talunùmoside I and 3-O-ß-d-glucuronopyranosyl serjanic acid. These saponins are glycosides of serjanic or phytolaccinic acid. Their structures were established on two basis: first, their spectral data, mainly HR-TOFESIMS, 1D-NMR ((1)H, (13)C, DEPT) and 2D-NMR ((1)H(1)H COSY, TOCSY, HSQC, HMBC, and ROESY), and second by comparison with literature data. These compounds were evaluated for their cytotoxic, antileishmanial and hemolytic activities. No antileishmanial or hemolytic activities were revealed, however zebirioside C and zebirioside I showed cytotoxicity against fibroblasts with IC50 of 6.4 and 5.6 µM, respectively.

The Elastin Receptor Complex: A Unique Matricellular Receptor with High Anti-tumoral Potential.

Elastin, one of the longest-lived proteins, confers elasticity to tissues with high mechanical constraints. During aging or pathophysiological conditions such as cancer progression, this insoluble polymer of tropoelastin undergoes an important degradation leading to the release of bioactive elastin-derived peptides (EDPs), named elastokines. EDP exhibit several biological functions able to drive tumor development by regulating cell proliferation, invasion, survival, angiogenesis, and matrix metalloproteinase expression in various tumor and stromal cells. Although, several receptors have been suggested to bind elastokines (αvß3 and αvß5 integrins, galectin-3), their main receptor remains the elastin receptor complex (ERC). This heterotrimer comprises a peripheral subunit, named elastin binding protein (EBP), associated to the protective protein/cathepsin A (PPCA). The latter is bound to a membrane-associated protein called Neuraminidase-1 (Neu-1). The pro-tumoral effects of elastokines have been linked to their binding onto EBP. Additionally, Neu-1 sialidase activity is essential for their signal transduction. Consistently, EDP-EBP interaction and Neu-1 activity emerge as original anti-tumoral targets. Interestingly, besides its direct involvement in cancer progression, the ERC also regulates diabetes outcome and thrombosis, an important risk factor for cancer development and a vascular process highly increased in patients suffering from cancer. In this review, we will describe ERC and elastokines involvement in cancer development suggesting that this unique receptor would be a promising therapeutic target. We will also discuss the pharmacological concepts aiming at blocking its pro-tumoral activities. Finally, its emerging role in cancer-associated complications and pathologies such as diabetes and thrombotic events will be also considered.

A second-generation ferrocene-iminosugar hybrid with improved fucosidase binding properties.

The synthesis and the biological evaluation of a new ferrocenyl-iminosugar conjugate designed for fucosidase inhibitory and anticancer activity is described. The compound showed strong affinity for fucosidase from bovine kidney (Ki=23 nM) and from Bacteroides thetaiotaomicron (Ki=150 nM), displaying a 10-fold tighter binding affinity for these enzymes than the previous analogs. The interaction pattern that improves binding has been evaluated through structural analysis of the inhibitor-enzyme complex. The ferrocenyl-iminosugar exhibits significant anticancer activity on MDA-MB-231 and SK-MEL28 cell lines at 100 µM.

Uncoupling of Elastin Complex Receptor during In Vitro Aging Is Related to Modifications in Its Intrinsic Sialidase Activity and the Subsequent Lactosylceramide Production.

Degradation of elastin leads to the production of elastin-derived peptides (EDP), which exhibit several biological effects, such as cell proliferation or protease secretion. Binding of EDP on the elastin receptor complex (ERC) triggers lactosylceramide (LacCer) production and ERK1/2 activation following ERC Neu-1 subunit activation. The ability for ERC to transduce signals is lost during aging, but the mechanism involved is still unknown. In this study, we characterized an in vitro model of aging by subculturing human dermal fibroblasts. This model was used to understand the loss of EDP biological activities during aging. Our results show that ERC uncoupling does not rely on Neu-1 or PPCA mRNA or protein level changes. Furthermore, we observe that the membrane targeting of these subunits is not affected with aging. However, we evidence that Neu-1 activity and LacCer production are altered. Basal Neu-1 catalytic activity is strongly increased in aged cells. Consequently, EDP fail to promote Neu-1 catalytic activity and LacCer production in these cells. In conclusion, we propose, for the first time, an explanation for ERC uncoupling based on the age-related alterations of Neu-1 activity and LacCer production that may explain the loss of EDP-mediated effects occurring during aging.

Interaction between the elastin peptide VGVAPG and human elastin binding protein.

The elastin binding protein (EBP), a spliced variant of lysosomal ß-galactosidase, is the primary receptor of elastin peptides that have been linked to emphysema, aneurysm and cancer progression. The sequences recognized by EBP share the XGXXPG consensus pattern found in numerous matrix proteins, notably in elastin where the VGVAPG motif is repeated. To delineate the elastin binding site of human EBP, we built a homology model of this protein and docked VGVAPG on its surface. Analysis of this model suggested that Gln-97 and Asp-98 were required for interaction with VGVAPG because they contribute to the definition of a pocket thought to represent the elastin binding site of EBP. Additionally, we proposed that Leu-103, Arg-107, and Glu-137 were essential residues because they could interact with VGVAPG itself. Site-directed mutagenesis experiments at these key positions validated our model. This work therefore provides the first structural data concerning the interaction of the VGVAPG with its cognate receptor. The present structural data should now allow the development of EBP-specific antagonists.