Evaluation of the hydrating benefits of a cationic hyaluronic acid: From biological evaluation to consumer home use trial.

Active ingredients are often assessed based on physiological measurements, but innovative technologies to measure skin sensations can provide a holistic volunteer assessment of the use of an ingredient. In this paper, the hydrating benefits of a cationic hyaluronic acid (HA) were evaluated alongside clinical biometrics and innovative cognitive measurements to determine how biological benefits correlated with volunteers' feelings and perceptions of hydration. The results demonstrated that cationic HA provides hydrating benefits at the clinical level due to its film-forming properties. Through the use of innovative behavioural measurement tools, we were able to show that these outcomes are perceived by naïve consumers in real-life conditions. In addition, the benefits of cationic HA reported by users were in accordance with the mental representation they had related to the use of HA, thus the product achieved complete sensorial embodiment. We can conclude that the combination of clinical evaluations and home use trials consolidates product assessment when seeking to measure consumer satisfaction with proven biological benefits.

Les ingrédients actifs sont souvent évalués sur la base de mesures physiologiques, mais des technologies innovantes de mesure des sensations des consommateurs peuvent fournir une évaluation holistique de l'utilisation d'un ingrédient. Dans cet article, les avantages hydratants d'un acide hyaluronique (AH) cationique ont été évalués parallèlement par des mesures biométriques cliniques et par des mesures cognitives innovantes afin de déterminer la correlation entre l'efficacité biologique et les sensations des volontaires en matière d'hydratation. Les résultats biologiques ont démontré que l'acide hyaluronique cationique offre des avantages hydratants au niveau clinique grâce à ses propriétés filmogènes. Grâce à l'utilisation d'outils de mesure comportementale innovants, nous avons également pu montrer que ces résultats sont perçus par des consommateurs naïfs dans des conditions réelles d'utilisation. De plus, les avantages de l'AH cationique rapportés par les utilisateurs étaient conformes à la représentation mentale qu'ils avaient des propriétés de l'AH, de sorte que l'expérience produit une congruence sensorielle complète. Nous pouvons conclure que la combinaison d'évaluations cliniques et d'essais en conditions réelles d'utilisation consolide l'évaluation des produits lorsque l'on cherche à mesurer la satisfaction des consommateurs.

Reactivating the extracellular matrix synthesis of sulfated glycosaminoglycans and proteoglycans to improve the human skin aspect and its mechanical properties.

BACKGROUND: The aim of this study was to demonstrate that a defined cosmetic composition is able to induce an increase in the production of sulfated glycosaminoglycans (sGAGs) and/or proteoglycans and finally to demonstrate that the composition, through its combined action of enzyme production and synthesis of macromolecules, modulates organization and skin surface aspect with a benefit in antiaging applications. MATERIALS AND METHODS: Gene expression was studied by quantitative reverse transcription polymerase chain reaction using normal human dermal fibroblasts isolated from a 45-year-old donor skin dermis. De novo synthesis of sGAGs and proteoglycans was determined using Blyscan™ assay and/or immunohistochemical techniques. These studies were performed on normal human dermal fibroblasts (41- and 62-year-old donors) and on human skin explants. Dermis organization was studied either ex vivo on skin explants using bi-photon microscopy and transmission electron microscopy or directly in vivo on human volunteers by ultrasound technique. Skin surface modification was investigated in vivo using silicone replicas coupled with macrophotography, and the mechanical properties of the skin were studied using Cutometer. RESULTS: It was first shown that mRNA expression of several genes involved in the synthesis pathway of sGAG was stimulated. An increase in the de novo synthesis of sGAGs was shown at the cellular level despite the age of cells, and this phenomenon was clearly related to the previously observed stimulation of mRNA expression of genes. An increase in the expression of the corresponding core protein of decorin, perlecan, and versican and a stimulation of their respective sGAGs, such as chondroitin sulfate and heparan sulfate, were found on skin explants. The biosynthesis of macromolecules seems to be correlated at the microscopic level to a better organization and quality of the dermis, with collagen fibrils having homogenous diameters. The dermis seems to be compacted as observed on images obtained by two-photon microscopy and ultrasound imaging. At the macroscopic level, this dermis organization shows a smoothed profile similar to a younger skin, with improved mechanical properties such as firmess. CONCLUSION: The obtained results demonstrate that the defined cosmetic composition induces the synthesis of sGAGs and proteoglycans, which contributes to the overall dermal reorganization. This activity in the dermis in turn impacts the surface and mechanical properties of the skin.

Trihydroxybenzoic acid glucoside as a global skin color modulator and photo-protectant.

BACKGROUND: 3,4,5-Trihydroxybenzoic acid glucoside (THBG), a molecule produced by an original biocatalysis-based technology, was assessed in this study with respect to its skin photoprotective capacity and its skin color control property on Asian-type skin at a clinical level and on skin explant culture models. METHODS: The double-blinded clinical study was done in comparison to a vehicle by the determination of objective color parameters thanks to recognized quantitative and qualitative analysis tools, including Chroma-Meter, VISIA-CR™, and SIAscope™. Determination of L* (brightness), a* and b* (green-red and blue-yellow chromaticity coordinates), individual typology angle, and C* (chroma) and h* (hue angle) parameters using a Chroma-Meter demonstrated that THBG is able to modify skin color while quantification of ultraviolet (UV) spots by VISIA-CR™ confirmed its photoprotective effect. The mechanism of action of THBG molecule was determined using explant skin culture model coupled to histological analysis (epidermis melanin content staining). RESULTS: We have demonstrated that THBG was able to modulate significantly several critical parameters involved in skin color control such as L* (brightness), a* (redness), individual typology angle (pigmentation), and hue angle (yellowness in this study), whereas no modification occurs on b* and C* parameters. We have demonstrated using histological staining that THBG decrease epidermis melanin content under unirradiated and irradiated condition. We also confirmed that THBG molecule is not a sunscreen agent. CONCLUSION: This study demonstrated that THBG controls skin tone via the inhibition of melanin synthesis as well as the modulation of skin brightness, yellowness, and redness.

Combination of new multifunctional molecules for erythematotelangiectatic rosacea disorder.

BACKGROUND: Rosacea, a common chronic skin disorder, is currently managed by patient education, pharmacological drugs, medical devices (laser and light therapies), and use of proper skin cares. Unfortunately, none of these actual treatments used alone or in combination is curative, and so we proposed a dermocosmetic active ingredient to mitigate some aspects of the rosacea and particularly for erythematotelangiectatic rosacea. METHODS: Dermocosmetic active ingredient is composed of three glucosylated derivatives of natural plants hydroxybenzoic acid and hydroxycinnamic acids (rosmarinic acid, gallic acid, and caffeic acid). Anti-inflammatory, anti-angiogenesis, and anti-degranulation studies were done on cellular models (keratinocytes, mast cells, and endothelial cells). Efficiency of the active ingredient in comparison to placebo was assessed clinically on human volunteers having erythematotelangiectatic rosacea. The active and placebo were applied topically twice a day for 28 days. Biometrical analyses were done using a siascope tool. RESULTS: We found that the active ingredient decreases inflammation (inhibition of interleukin-8 and tumor necrosis factor release), decreases degranulation of mast cells (inhibition of histamine release), and controls angiogenesis mechanism (inhibition of the production of vascular endothelial growth factor and neovessel formation) on cellular models. Study on human volunteers confirmed macroscopically the efficiency of this active ingredient, as we observed no neovessel formation and less visible vessels. CONCLUSION: Although rosacea is a skin condition disorder that is difficult to heal, the studies have shown that this active ingredient could be a dermocosmetic support, especially for erythematotelangiectatic rosacea armamentarium. The active ingredient was topically applied on the face for 28 days and improved erythematotelangiectatic rosacea symptoms either by decreasing them (vessels are less visible) or by limiting their development (any neovessels). The active ingredient decreases inflammation (inhibition of interleukin-8 and tumor necrosis factor release), decreases degranulation of mast cells (inhibition of histamine release), and limits the angiogenesis process (inhibition of vascular endothelial growth factor production and neovessel formation).

Time course of the cross-over effect of fatigue on the contralateral muscle after unilateral exercise.

We investigated the cross-over effect of muscle fatigue and its time course on the non-exercising contralateral limb (NEL) after unilateral fatiguing contractions of the ipsilateral exercising limb (EL). For this purpose, 15 males performed two bouts of 100-second maximal isometric knee extensions with the exercising limb, and neuromuscular function of both the EL and NEL was assessed before (PRE), after a first fatiguing exercise (MID) and after a second fatiguing exercise (POST). Maximal voluntary isometric torque production declined in the EL after the first bout of exercise (-9.6%; p<0.001) while in the NEL, the decrease occurred after the second bout of exercise (-10.6%; p<0.001). At MID, torque decline of the EL was strictly associated to an alteration of the mechanical twitch properties evoked by neurostimulation of the femoral nerve (i.e., peak twitch torque, maximal rate of twitch development). According to these markers, we suggest that peripheral fatigue occurred. At POST, after the second bout of exercise, the voluntary activation level of the knee extensor muscles was altered from PRE (-9.1%; p<0.001), indicating an overall central failure in both the EL and NEL. These findings indicate that two bouts of unilateral fatiguing exercise were needed to induce a cross-over effect of muscle fatigue on the non-exercising contralateral limb. Differential adjustments of the motor pathway (peripheral fatigue vs. central fatigue) might contribute to the respective torque decline in the EL and the NEL. Given that our unilateral fatiguing exercise induced immediate maximal torque reduction in the EL and postponed the loss of torque production in the NEL, it is also concluded that the time course of muscle fatigue differed between limbs.

Mining for hemicellulases in the fungus-growing termite Pseudacanthotermes militaris using functional metagenomics.

BACKGROUND: The metagenomic analysis of gut microbiomes has emerged as a powerful strategy for the identification of biomass-degrading enzymes, which will be no doubt useful for the development of advanced biorefining processes. In the present study, we have performed a functional metagenomic analysis on comb and gut microbiomes associated with the fungus-growing termite, Pseudacanthotermes militaris. RESULTS: Using whole termite abdomens and fungal-comb material respectively, two fosmid-based metagenomic libraries were created and screened for the presence of xylan-degrading enzymes. This revealed 101 positive clones, corresponding to an extremely high global hit rate of 0.49%. Many clones displayed either ß-d-xylosidase (EC 3.2.1.37) or α-l-arabinofuranosidase (EC 3.2.1.55) activity, while others displayed the ability to degrade AZCL-xylan or AZCL-ß-(1,3)-ß-(1,4)-glucan. Using secondary screening it was possible to pinpoint clones of interest that were used to prepare fosmid DNA. Sequencing of fosmid DNA generated 1.46 Mbp of sequence data, and bioinformatics analysis revealed 63 sequences encoding putative carbohydrate-active enzymes, with many of these forming parts of sequence clusters, probably having carbohydrate degradation and metabolic functions. Taxonomic assignment of the different sequences revealed that Firmicutes and Bacteroidetes were predominant phyla in the gut sample, while microbial diversity in the comb sample resembled that of typical soil samples. Cloning and expression in E. coli of six enzyme candidates identified in the libraries provided access to individual enzyme activities, which all proved to be coherent with the primary and secondary functional screens. CONCLUSIONS: This study shows that the gut microbiome of P. militaris possesses the potential to degrade biomass components, such as arabinoxylans and arabinans. Moreover, the data presented suggests that prokaryotic microorganisms present in the comb could also play a part in the degradation of biomass within the termite mound, although further investigation will be needed to clarify the complex synergies that might exist between the different microbiomes that constitute the termitosphere of fungus-growing termites. This study exemplifies the power of functional metagenomics for the discovery of biomass-active enzymes and has provided a collection of potentially interesting biocatalysts for further study.

Identification of NF-κB modulation capabilities within human intestinal commensal bacteria.

The intestinal microbiota plays an important role in modulation of mucosal immune responses. To seek interactions between intestinal epithelial cells (IEC) and commensal bacteria, we screened 49 commensal strains for their capacity to modulate NF-κB. We used HT-29/kb-seap-25 and Caco-2/kb-seap-7 intestinal epithelial cells and monocyte-like THP-1 blue reporter cells to measure effects of commensal bacteria on cellular expression of a reporter system for NF-κB. Bacteria conditioned media (CM) were tested alone or together with an activator of NF-κB to explore its inhibitory potentials. CM from 8 or 10 different commensal species activated NF-κB expression on HT-29 and Caco-2 cells, respectively. On THP-1, CM from all but 5 commensal strains stimulated NF-κB. Upon challenge with TNF-α or IL-1ß, some CM prevented induced NF-κB activation, whereas others enhanced it. Interestingly, the enhancing effect of some CM was correlated with the presence of butyrate and propionate. Characterization of the effects of the identified bacteria and their implications in human health awaits further investigations.

[Study on turnaround time of biological analysis in urgent need in hospital laboratories]. / Étude sur les délais de rendu de résultats d'examens biologiques demandés en urgence dans les laboratoires hospitaliers.

We have assessed turnaround time (TAT) for urgent laboratory analysis. Twelve hospital laboratories participated to this study. All laboratories have organized a classification of a management system of urgent analyses. The TAT reporting were relatively homogeneous for 12 laboratories. We have defined TAT as time of specimen receipt in the laboratory to time of results reporting. This TAT divides into 4 groups: close to 50 minutes for analyses as TP, D-dimeres, CRP (C Protein Reactive), HCG, troponin, alcoholhemia, K, lipase; 35 minutes for the cytology of cerebrospinal fluid; 25 minutes for complete blood cell count and 15 minutes for blood gases. All laboratories have accepted to TAT as a quality indicator. Quality indicator data should be collected in time to identify and correct problems to implemente effective interventions and to standardize processes among clinical laboratories.

Functional metagenomics: a high throughput screening method to decipher microbiota-driven NF-κB modulation in the human gut.

BACKGROUND/AIM: The human intestinal microbiota plays an important role in modulation of mucosal immune responses. To study interactions between intestinal epithelial cells (IECs) and commensal bacteria, a functional metagenomic approach was developed. One interest of metagenomics is to provide access to genomes of uncultured microbes. We aimed at identifying bacterial genes involved in regulation of NF-κB signaling in IECs. A high throughput cell-based screening assay allowing rapid detection of NF-κB modulation in IECs was established using the reporter-gene strategy to screen metagenomic libraries issued from the human intestinal microbiota. METHODS: A plasmid containing the secreted alkaline phosphatase (SEAP) gene under the control of NF-κB binding elements was stably transfected in HT-29 cells. The reporter clone HT-29/kb-seap-25 was selected and characterized. Then, a first screening of a metagenomic library from Crohn's disease patients was performed to identify NF-κB modulating clones. Furthermore, genes potentially involved in the effect of one stimulatory metagenomic clone were determined by sequence analysis associated to mutagenesis by transposition. RESULTS: The two proinflammatory cytokines, TNF-α and IL-1ß, were able to activate the reporter system, translating the activation of the NF-κB signaling pathway and NF-κB inhibitors, BAY 11-7082, caffeic acid phenethyl ester and MG132 were efficient. A screening of 2640 metagenomic clones led to the identification of 171 modulating clones. Among them, one stimulatory metagenomic clone, 52B7, was further characterized. Sequence analysis revealed that its metagenomic DNA insert might belong to a new Bacteroides strain and we identified 2 loci encoding an ABC transport system and a putative lipoprotein potentially involved in 52B7 effect on NF-κB. CONCLUSIONS: We have established a robust high throughput screening assay for metagenomic libraries derived from the human intestinal microbiota to study bacteria-driven NF-κB regulation. This opens a strategic path toward the identification of bacterial strains and molecular patterns presenting a potential therapeutic interest.

A quick in vitro pathway from prokaryotic genomic libraries to enzyme discovery.

Screening of prokaryotic genomes in order to identify enzymes with a desired catalytic activity can be performed in vivo in bacterial cells. We propose a strategy of in vitro expression screening of large prokaryotic genomic libraries based on Escherichia coli cell-free transcription-translation systems. Because cell-based expression may be limited by poor yield or protein misfolding, cell-free expression systems may be advantageous in permitting a more comprehensive screen under conditions optimized for the desired enzyme activity. However, monocistronic messages with an improved leader initiation context are typically used for protein production in vitro. Here, we describe successful use of a Pseudoalteromonas genomic DNA library for in vitro expression of DNA fragments carrying multiple open reading frames (ORFs) in the context of their authentic translation initiation sites and regulatory regions. We show that ORFs located far from the 5' and 3' ends of polycistronic transcripts can be expressed at a sufficient level in an in vitro transcription-translation system in order to allow functional screening. We demonstrate the overall cell-free functional screen strategy with the successful selection of an esterase from Pseudoalteromonas.

Drugs from hidden bugs: their discovery via untapped resources.

The drug discovery process is a starving machine requiring constant feeding with new chemical compounds. Synthetic or natural scaffolds: what are the best sources? While synthetic molecules are rapidly generated by combinatorial chemistry, they show lower chemical diversity than their natural counterparts. A significant fraction of known natural products is issued from microbial secondary metabolism; however, more than 95% of bacterial organisms remain unexploited as a source of active chemical compounds due to their cultivation difficulties. Recent technological advances in metagenomics have provided reliable access to chemicals of these hidden bugs, thus opening up new opportunities for feeding the machine.

Overexpression of the nucleolar protein nucleophosmin/B23 in collagen lattice-cultured fibroblasts: potential role in the control of protein synthesis.

Fibroblasts cultivated in tridimensional collagen lattices exhibit a downregulation of protein synthesis, related to decreased ribosomal RNA (rRNA) content and half life, when compared to monolayer cultivated cells. The involvement in this process of nucleophosmin/B23, a nucleolar phosphoprotein with ribonuclease properties, was checked. We compared production of nucleophosmin/B23 in monolayer and collagen lattice cultured fibroblasts. A significant increase of nucleophosmin/B23 mRNA levels was noticed in lattice-cultured fibroblasts vs monolayers (+154%, p < 0.05). A concomitant enhancement of nucleolar nucleophosmin/B23 content was found (+112%, p < 0.001). Simultaneously, ribonuclease activity contained in nucleolar extracts from collagen lattice-cultured fibroblasts was significantly increased (+54%, p < 0.01). These data demonstrate that extracellular collagen matrix induces the overexpression of nucleophosmin/B23, and suggest that the regulation of protein syntheses in collagen lattice cultures may be explained, at least partly, by an increased degradation of neosynthesized rRNAs dependent on nucleophosmin.