Ethylated analogue of Zingerone: A new and eco-respectful preservative in cosmetics.

OBJECTIVE: This article describes the eco-design of a new preservative in cosmetics based on bio-inspiration of natural extracts from traditional medicines. In order to reach the multiple specification targets, various structures have been synthesized and evaluated to select the one demonstrating broad antimicrobial spectrum with favorable environmental profile and application potential to a wide variety of formulas. METHODS: In order to evaluate the antimicrobial activity of the synthesized structures, the method of the challenge test consisting in an artificial contamination of the sample with collection microbial strains and evaluation of the number of revivable microorganisms was used to select the most promising candidate. Validation of its antimicrobial potential was later confirmed on Gram positive and Gram negative bacteria, yeast and mold with measurement of its Minimum Inhibitory Concentration (MIC) in comparison with known preservatives. Environmental impact assessment of the selected candidate was achieved with the help of ready biodegradability and aquatic ecotoxicity tests performed according to appropriate Organization tes a strfor Economic Co-operation and Development (OECD) and European Union (EU) guidelinesy. RESULTS: Bio-inspired from turmeric and ginger extracts, an ethylated analog of Zingerone (EZ) with the chemical name 4-(3-ethoxy-4-hydroxyphenyl)butan-2-one demonstrates the strongest activity on Escherichia coli, Enterococcus faecalis, Pseudomonas aeruginosa and Candida albicans. Moreover, EZ shows a solubility in water two times higher than that of Zingerone thus increasing its interest as a potential preservative. Finally, its assessment of ready biodegradability and aquatic ecotoxicity in OECD-EU tests with a favorable environmental profile confirms its unique interest and fully justifies its use in cosmetic formulas as an eco-respectful preservative. CONCLUSION: Bio-inspiration based on technologies without noteworthy side effects but also on eco-design, particularly through the use of measures of potential environmental impact very upstream of a development, are two fundamental elements for the launching of new eco-friendly cosmetic ingredients. This approach has thus validated the strong potential of EZ as a preservative of eco-respectful formulas. The selection of EZ is also a very good example of the achievement of two key objectives targeted by cosmetic companies for the development of a novel active ingredient: environmental performance and technical performance.

OBJECTIF: Cet article décrit l'éco-conception d'un nouveau conservateur en cosmétique à partir de la bio-inspiration d'extraits naturels utilisées dans les médecines traditionnelles. Afin d'atteindre les cibles de spécification multiples, diverses structures ont été synthétisées et évaluées pour choisir celle qui présente un large spectre antimicrobien avec un profil environnemental favourable et un potentiel d'application pour une grande variété de formules. MÉTHODES: Afin d'évaluer l'activité antimicrobienne des structures synthétisées, la méthode du challenge test consistant en une contamination artificielle de l'échantillon par des souches microbiennes de collection suivie de l'évaluation du nombre de microorganismes revivifiables a été utilisée pour sélectionner le candidat le plus prometteur. La validation de son potentiel antimicrobien a par la suite été confirmée sur des bactéries à Gram positif et à Gram négatif, des levures et des moisissures grâce à la mesure de sa Concentration Minimale Inhibitrice (CMI) par rapport aux agents de conservation connus. L'évaluation de l'impact sur l'environnement du candidat sélectionné a été réalisée à l'aide de tests de biodégradabilité facile et d'écotoxicité aquatique réalisés selon les lignes directrices appropriées de l'Organization de Coopération et de Développement Economiques (OCDE). RESULTATS: Bio-inspiré des extraits de curcuma et de gingembre, un analogue éthylé de Zingerone nommé ETHYLZINGERONE (EZ) avec pour nom chimique 4-(3-ethoxy-4-hydroxyphenyl)butan-2-one démontre l'activité la plus forte sur Escherichia coli, Enterococcus faecalis, Pseudomonas aeruginosa et Candida albicans. De plus, EZ montre une solubilité dans l'eau 2 fois supérieure à celle de la Zingerone renforçant ainsi son intérêt en tant que conservateur potentiel. Enfin, son évaluation dans les tests OCDE de la biodégradabilité facile et de l'écotoxicité aquatique avec un profil environnemental favourable confirme son intérêt unique et justifie pleinement son utilization dans les formules cosmétiques comme conservateur respectueux de l'environnement. CONCLUSION: La bio-inspiration basée sur des technologies sans effet secondaire notoire mais aussi l'éco-conception par l'utilization de mesures de l'impact environnemental potentiel très en amont d'un développement sont deux éléments fondamentaux pour la mise sur le marché de nouveaux ingrédients cosmétiques éco-respectueux. Cette approche a ainsi permis de valider le fort potentiel de EZ comme agent de conservation de formules respectueuses de l'environnement. La sélection de EZ est également un très bon exemple de l'atteinte de deux objectifs-clés recherchés par les entreprises cosmétiques pour le développement d'un nouvel actif: la performance environnementale et la performance technique.

Divergent Entry to C-Glycosides from Unprotected Sugars.

An efficient, divergent, and straightforward access to novel C-glycosides has been developed, namely, α-hydroxy carboxamide and carboxylic acid derivatives, via a green and scalable process from unprotected carbohydrates. The method involves condensation of 1,3-dimethylbarbituric acid with unprotected sugars followed by subsequent barbiturate oxidative cleavage in the same pot. Further expanding of the chemistry led to the development of efficient entries to diastereoisomerically pure C-glycosyl-α-hydroxy esters or amides through nucleophilic attack on a readily available and versatile key lactone intermediate.

A jasmonic acid derivative improves skin healing and induces changes in proteoglycan expression and glycosaminoglycan structure.

BACKGROUND: Jasmonates are plant hormones that exhibit anti-cancer and anti-inflammatory properties and have therefore raised interest for human health applications. The molecular basis of these activities remains poorly understood, although increasing evidence suggests that a variety of mechanisms may be involved. Recently, we have reported that a jasmonate derivative (JAD) displayed anti-aging effects on human skin by inducing extracellular matrix (ECM) remodeling. Based on this observation, we have investigated here the effects of JAD on proteoglycans and glycosaminoglycan (GAG) polysaccharides, which are major cell-surface/ECM components and are involved in a multitude of biological processes. In parallel, we have examined the ability of JAD to promote growth factor activities and improve skin wound healing. METHODS: Proteoglycan expression was analyzed on epidermal primary keratinocytes and reconstituted skin epidermis, using electron/immunofluorescence microscopy, western blotting and flow cytometry. GAG composition was determined by disaccharide analysis. Finally, biological activities of JAD were assessed in cellulo, in FGF-7 induced migration/proliferation assays, as well as in vivo, using a suction blister model performed on 24 healthy volunteers. RESULTS: JAD was found to induce expression of major skin proteoglycans and to induce subtle changes in GAG structure. In parallel, we showed that JAD promoted FGF-7 and improved skin healing by accelerating epithelial repair in vivo. CONCLUSION: This study highlights JAD as a promising compound for investigating GAG structure-function relationships and for applications in skin cosmetic /corrective strategies. GENERAL SIGNIFICANCE: We propose here a novel mechanism, by which jasmonate derivatives may elicit biological activities in mammals.

Sweating the small stuff: Glycoproteins in human sweat and their unexplored potential for microbial adhesion.

There is increasing evidence that secretory fluids such as tears, saliva and milk play an important role in protecting the human body from infection via a washing mechanism involving glycan-mediated adhesion of potential pathogens to secretory glycoproteins. Interaction of sweat with bacteria is well established as the cause of sweat-associated malodor. However, the role of sweat glycoproteins in microbial attachment has received little, if any, research interest in the past. In this review, we demonstrate how recent published studies involving high-throughput proteomic analysis have inadvertently, and fortuitously, exposed an abundance of glycoproteins in sweat, many of which have also been identified in other secretory fluids. We bring together research demonstrating microbial adhesion to these secretory glycoproteins in tears, saliva and milk and suggest a similar role of the sweat glycoproteins in mediating microbial attachment to sweat and/or skin. The contribution of glycan-mediated microbial adhesion to sweat glycoproteins, and the associated impact on sweat derived malodor and pathogenic skin infections are unchartered new research areas that we are beginning to explore.

The anti-ageing potential of a new jasmonic acid derivative (LR2412): in vitro evaluation using reconstructed epidermis Episkin™.

Jasmonic acid is involved in plant wound repair and tissue regeneration, but no study has been reported in human skin. The effect of a jasmonic acid derivative, tetra-hydro-jasmonic acid (LR2412, 1 and 10 µm) was investigated on an in vitro reconstructed skin model, Episkin™. Using real time RTQPCR studies, results showed an increase in hyaluronan synthase 2 (HAS2) and hyaluronase synthase 3 (HAS3) expression. Furthermore, an increase in hyaluronic acid (HA) deposits in basal and suprabasal layers of the epidermis was observed. The percentage of positive Ki67 keratinocytes in the basal layer as well as the epidermis thickness were seen to increase. Immunohistochemistry studies showed that the synthesis of late differentiation proteins filaggrin and transglutaminase 1 was not modified. The human epidermis is known to thin with age while HA content has been reported to decrease. These results illustrate the potential of LR2412 in counteracting signs of skin ageing.

Interactions and encapsulation of vitamins C, B3, and B6 with dendrimers in water.

Titrations of commercial diaminobutane (DAB) and polyamidoamine (PAMAM) dendrimers by vitamins C (ascorbic acid, AA), B(3) (nicotinic acid), and B(6) (pyridoxine) were monitored by (1)H NMR spectroscopy using the chemical shifts of both dendrimer and vitamin protons and analyzed by comparison with the titration of propylamine. Quaternarizations of the terminal primary amino groups and intradendritic tertiary amino groups, which are nearly quantitative with vitamin C, were characterized by more or less sharp variations (Deltadelta) of the (1)H chemical shift (delta) at the equivalence points. The peripheral primary amino groups of the DAB dendrimers were quaternarized first, but not selectively, whereas a sharp chemical-shift variation was recorded for the inner methylene protons near the tertiary amines, thereby indicating encapsulation, when all the dendritic amines were quaternarized. With DAB-G5-64-NH(2), some excess acid is required to protonate the inner amino groups, presumably because of basicity decrease due to excess charge repulsion. On the other hand, this selectivity was not observed with PAMAM dendrimers. The special case of the titration of the dendrimers by vitamin B(6) indicates only dominant supramolecular hydrogen-bonding interactions and no quaternarization, with core amino groups being privileged, which indicates the strong tendency to encapsulate vitamins. With vitamin B(3), a carboxylic acid, titration of DAB-G3-16-NH(2) shows that only six peripheral amino groups are protonated on average, even with excess vitamin B(3), because protonation is all the more difficult due to increased charge repulsion, as positive charges accumulate around the dendrimer. Inner amino groups interact with this vitamin, however, thus indicating encapsulation presumably with supramolecular hydrogen bonding without much charge transfer.

Synthesis of Pro-Xylane: a new biologically active C-glycoside in aqueous media.

The scope and limitation of Lubineau's reaction were evaluated for the synthesis of C-glycosides (compounds 1-13). Further transformation of side chain carbonyl was also achieved (compounds 16-23). Optimization of these two steps was investigated in xylose case. Some of the compounds were shown to stimulate sulfated glycosaminoglycans (GAGs) synthesis. Compound 20 (called Pro-Xylane) was identified as the best activator of GAGs biosynthesis. Pro-Xylane was developed using environmentally friendly conditions relevant to 'Green-Chemistry' principles and launched on the market in September 2006. This compound is the first example of 'Green' chemical used in cosmetic.

Improvement of the dermal epidermal junction in human reconstructed skin by a new c-xylopyranoside derivative.

Skin aging entails drastic changes in the extracellular dermal matrix (ECM) and dermal-epidermal junction (DEJ). These biological alterations are reflected in the clinical signs of aged skin. A new C-xylopyranoside derivative, C-beta-D-xylopyranoside-2-hydroxy-propane (C-Xyloside) has been shown to induce neo-synthesis of matrix proteins such as glycosaminoglycans and heparan sulfate proteoglycans. The aim of this study was to assess the effects of C-Xyloside on markers of the dermal epidermal junction. Basement membrane components, collagen IV, collagen VII and laminin 5 as well as sub-epidermal dermal markers, pro-collagen I and fibrillin 1 were analysed using immunohistochemistry in a reconstructed skin model, including a dermal equivalent populated with living fibroblasts. Levels of mRNA of collagen VII alpha1 and collagen IV alpha1 were evaluated in dermal fibroblasts using RT-PCR. The results showed that C-Xyloside significantly induced a higher deposition of basement membrane and DEJ proteins in the reconstructed skin model and increased collagen VII gene expression. These findings indicate that, in addition to stimulating glycosaminoglycan and heparan sulfate proteoglycan expression, C-Xyloside improves the morphogenesis of the whole DEJ, and strongly suggests beneficial effects in aged skin from restoring DEJ integrity.

Expression of NAD+ dependent 15-hydroxyprostaglandin dehydrogenase and protection of prostaglandins in human hair follicle.

NAD(+) dependent 15-hydroxyprostaglandin dehydrogenate (15-PGDH) catalyses oxidation of 15(S)-hydroxyl group of prostaglandins and as a result inactivates their physiological potential. Positive effects of prostaglandins or prostaglandin analogues were reported on terminal hair, vellus hair or eyelash growth and a complex prostaglandin network was recently described in human hair follicle. In the present study, we showed that 15-PGDH was expressed in human hair follicle mainly in melanocytes and keratinocytes, which brought us to consider this enzyme as a possible target to sustain local prostaglandin production. Using a recombinant enzymatic strategy, specific 15-PGDH inhibitors were screened. We identified a thiazolidine dione derivative exhibiting efficacy on follicular outer root sheath keratinocytes, since it concomitantly decreased the production of deactivated 13,14 dihydro 15-ketoprostaglandin F(2alpha) and sustained prostaglandin F(2alpha)in vitro production. In the context of recent interest in prostaglandins and prostaglandin analogues as hair regrowth agents, we postulated that the use of selected 15-PGDH inhibitors could reinforce or prolong the effect of these physiological mediators on hair and skin.

A new C-xylopyranoside derivative induces skin expression of glycosaminoglycans and heparan sulphate proteoglycans.

Severe structural changes, including deterioration of the mechanical properties of the dermis, occur during skin aging. It is well known that the degradation of the extracellular matrix contributes to the physical changes in aged skin. Whereas many studies have been devoted to age-related alterations of collagen fibrils, far less attention has been paid to another major family of extracellular matrix components, the glycosaminoglycans (GAGs) and proteoglycans (PGs). Heparan sulphate-proteoglycans, (HS-PGs), a subclass of the PG family that decreases during aging, regulate proliferation and proteolysis as well as matrix adhesion and assembly, and thus, may have important functions in skin. These PGs may represent important targets for dermo-cosmetology in fighting skin aging. The purpose of this study was to demonstrate the potential of a new C-xylopyranoside derivative (C-beta-D-xylopyranoside-2-hydroxy-propane simplified as C-Xyloside) to improve HS-PGs expression in human skin. In an organotypical model of corticosteroid atrophic human skin, characterized by a decrease of PGs expression, treatment with C-Xyloside improved expression of HS-PGs.