Contribution of cosmetic ingredients and skin care textures to emotions.

OBJECTIVE: Emotions play an important role in consumers' perception of a sensory experience. The objective of this work was to investigate the ability of basic skin care formulas (i.e. without interference of odour, colour and packaging) and pillar ingredients (i.e. emollients and rheology modifiers) to elicit emotions. Another objective was to track, as claimed by neurocosmetics, the possible effect of formulas to trigger emotions from their direct biochemical effects on the skin. METHODS: Standard methodologies were mobilized, combining subjective and behavioural parameters (i.e. verbatim, prosody and gesture). Sense and Story methodology based on a collection of metaphoric verbatim was conducted after an induction phase. In addition, an experimental electrophysiological real-time visualization method was tried as a first experience in cosmetics. Finally, the ability of formulations with emotional benefits to modulate the release of neuropeptides by sensory neurons was evaluated on a 3D human model (epidermis co-cultured with sensory neurons). RESULTS: Skin care formulas were shown to play a role in emotional potential and the types of emotion generated, while changing one ingredient mostly acted on the intensity of the emotions. Verbatim provided contrasted answers depending on the protocol, highlighting the interest of non-verbal approaches to detect subtle effects. The in vitro model substantiated physiological effects of skin care formulas with emotional potential on human skin sensory neuron activity. CONCLUSION: Emotions were impacted by the change in ingredients and were better captured through non-verbal methods.

OBJECTIF: Les émotions jouent un rôle important dans la perception qu'ont les consommateurs d'une expérience sensorielle. L'objectif de ce travail était d'étudier la capacité de formules de soins pour la peau de base (c'est­à­dire sans interférence d'odeur, de couleur, d'emballage) et d' ingrédients essentiels (c'est­à­dire les émollients et les modificateurs de rhéologie) à susciter des émotions. Un autre objectif était de suivre, comme le prétendent les neurocosmétiques, l'effet possible des formules à déclencher des émotions à partir de leurs effets biochimiques directs sur la peau. MÉTHODES: Des méthodologies standards ont été mises en œuvre, combinant des paramètres subjectifs et comportementaux (c'est­à­dire verbatim, prosodie et gestuelle). La méthodologie Sense & Story basée sur un ensemble de verbatim métaphoriques a été mise en œuvre après une phase d'induction. En outre, une méthode expérimentale de visualisation électrophysiologique en temps réel a été testée comme première expérience dans le domaine des cosmétiques. Enfin, la capacité des formulations présentant des bénéfices émotionnels à moduler la libération de neuropeptides par les neurones sensoriels a été évaluée sur un modèle humain 3D (épiderme co­cultivé avec des neurones sensoriels). RÉSULTATS: Il a été démontré que les formules de soins pour la peau jouent un rôle dans le potentiel émotionnel et les types d'émotions générées, tandis que le changement d'un ingrédient agit principalement sur l'intensité des émotions. Le verbatim a fourni des réponses contrastées selon le protocole, soulignant l'intérêt des approches non verbales pour détecter les effets subtils. Le modèle in vitro a confirmé les effets physiologiques des formules de soins pour la peau ayant un potentiel émotionnel sur l'activité des neurones sensoriels de la peau humaine. CONCLUSION: Les émotions ont été affectées par le changement d'ingrédients et ont été mieux saisies par des méthodes non verbales.

The World's First Acne Dysbiosis-like Model of Human 3D Ex Vivo Sebaceous Gland Colonized with Cutibacterium acnes and Staphylococcus epidermidis.

Acne-prone skin is associated with dysbiosis involving Cutibacterium acnes (C. acnes) and Staphylococcus epidermidis (S. epidermidis) causing increased seborrhea in sebaceous glands (SG) and inflammation. Human primary sebocytes were cultivated using 1.106 UFC/mL C. acnes Type IA (facial acne, ATCC6919) and/or 1.105 UFC/mL S. epidermidis (unknown origin, ATCC12228) for 48 h in our SEB4GLN-optimized media without antibiotics. Bacteria and sebocytes were enumerated and assessed to determine their viability. Lipid production was imaged and quantified via Nile Red staining. SG with hair follicles were microdissected from healthy skin and cultured using 1.105 UFC/mL C. acnes Type 1A and/or 1.104 UFC/mL S. epidermidis (wild-type facial skin strain) through prior fixation and immunostaining for MC5R, C. acnes and nuclei (DAPI) via Z-stack confocal microscopy bioimaging (Leica SP5X & FIJI software, Version 2.9.0). C. acnes growth was not impacted when co-cultivated with sebocytes (2D) or SG (3D) models. Phylotype IA stimulated sebocyte lipid production, which had no impact on viability. The S. epidermidis reference strain overproliferated, inducing sebocyte mortality. For 3D SG model, culture conditions were optimized using a wild-type facial skin strain at a lower concentration, 1:10 ratio to C. acnes, reduced contact time, sequential inoculation and rinsing step. Bioimaging revealed strong C. acnes labeling in the active areas of the pilosebaceous unit. S. epidermidis formed biofilm, which was distributed across the SG via non-specific fluorescence imaging. We developed an innovative model of a sebaceous gland that mimics acne-prone skin with lipid overproduction and virulent phylotype IA C. acnes inoculation.

Barrier disruption, dehydration and inflammation: Investigation of the vicious circle underlying dry skin.

OBJECTIVE: Many endogenous or exogenous factors, isolated or combined, can trigger dry skin disorder, leading to a water/lipids-depleted stratum corneum concomitant with uncomfortable rough and scaly skin surface. In a defensive reaction, the alteration of the skin barrier stimulates the production of cytokines to initiate homeostasis restoration but this can also induce an inflammatory response that further weakens the barrier. The two phenomena intertwining one another lead to the creation of a vicious circle, here called Inflamm'dryness, that maintains dry skin state. It is thus very important to investigate biological mechanisms involved in Inflamm'dryness to better manage dry skin. METHODS: A 3D model mimicking dry skin has been developed. Adjustment of tape stripping level allowed to reproduce skin barrier alterations and resulting inflammation involved in dry skin. The effect of Helichrysum stoechas extract on this downward spiral was then investigated to validate the concept. RESULTS: Tape-stripping permitted to successively remove the cell layers of the stratum corneum: the barrier function was altered and skin was inflamed creating a vicious circle, mimicking very dry skin prone to Inflamm'dryness. Helichrysum stoechas extract was not only able to resolve inflammation but also to reverse concurrently adverse tape-stripping effects and imparted significant structural and functional recovery of the barrier (e.g. on NMF and ceramides levels, TEWL, tissue organization). CONCLUSION: This 3D model reproduces Inflamm'dryness vicious circle present in dry skin and highlights the importance of breaking this process to improve dry skin conditions. Helichrysum stoechas extract is a promising active ingredient for the management of dry skin.

OBJECTIF: De nombreux facteurs endogènes ou exogènes, isoles ou combines, peuvent être à l'origine de sècheresse cutanée, conduisant à une peau en manque d'eau et de lipides : la peau tiraille, présente parfois un l'aspect rugueux (voire la présence de squames) et des sensations d'inconfort. Cette altération de la barrière cutanée induit la production de cytokines permettant la restauration de l'homéostasie de la peau mais induisant également une réponse inflammatoire fragilisant davantage la barrière cutanée. Ces deux phénomènes conduisent à la création d'un cercle vicieux, l'Inflamm'dryness, qui entretient l'état de sécheresse de la peau. Il semble donc important d'étudier les mécanismes biologiques impliqués dans le phénomène d'Inflamm'dryness afin de mieux prendre soin des peaux sèches. MÉTHODES: Un modèle 3D mimant une peau sèche a été développé. Un ajustement du nombre de tape-strippings a été nécessaire afin de reproduire les défauts de barrière ainsi que de l'inflammation caractéristiques des peaux sèches. L'effet d'un extrait d'Helichrysum stoechas sur cette spirale négative a ensuite été étudié pour valider le concept. RÉSULTATS: L'étape de tape-stripping a permis de retirer successivement les couches superficielles du stratum corneum: la fonction barrière est altérée et la peau est enflammée créant un cercle vicieux, mimant une peau très sèche sujette à l'Inflamm'dryness. L'extrait d'Helichrysum stoechas est non seulement capable de résoudre l'inflammation, mais également de restaurer la fonction barrière de la peau (quantités de NMF et de céramides, la perte insensible en eau, organisation des tissus…). CONCLUSION: Ce modèle 3D reproduit le cercle vicieux de l'Inflamm'dryness caractéristique des peaux sèches et met en évidence l'importance de rompre ce processus afin de remédier à la sécheresse cutanée. L'extrait d'Helichrysum stoechas développé est un actif prometteur pour le soin des peaux sèches.

Characterization of the Degradation Profile of Umbelliprenin, a Bioactive Prenylated Coumarin of a Ferulago Species.

Umbelliprenin is a secondary plant metabolite that displays promising chemopreventive, anti-inflammatory, and antigenotoxic properties. It possesses potential for applications to human welfare notably to prevent the emergence of cancer. For this purpose, stability studies are needed to define proper storage conditions and adapted formulations for this drug candidate. The identification of degradative products is a major concern for the preclinical development of umbelliprenin, providing also interesting information related to potential original phytochemicals formed in plants exposed to stressors. The stability profile of umbelliprenin under various stress conditions including exposure to heat, light, oxidation, and hydrolytic medium was assessed via HPLC/UV data. The data support that umbelliprenin undergoes inter- and intramolecular [2+2] cycloaddition under light exposure, leading respectively to a cyclobutane-umbelliprenin dimer and a 16-membered macrocycle. Their structures were characterized via MS and NMR data. It was shown that UV-A filters prevent this process, whereas UV-B filters and antioxidants are not or weakly effective. The study provides useful information for the preclinical development of umbelliprenin as an original chemopreventive agent.

Bioactive formulations with sugar-derived surfactants: a new approach for photoprotection and controlled release of promethazine.

Skin deep: A bioactive formulation for dermal delivery of antihistamines is obtained by using the original properties of catanionic associations towards self-assembly in water. The drug, which participates in its own transport, is preserved from photodegradation when solubilised in the bioactive formulation. The drug release through the skin is also delayed.

Spontaneous formation of vesicles in a catanionic association involving a head and tail functionalized amino-calix[6]arene.

An amino-calix[6]arene was combined with sugar-based surfactants, using an acid-base reaction, to obtain an original catanionic association. Physicochemical studies showed the spontaneous formation of stable vesicles in aqueous solution.