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.

Physiological benefits associated with facial skincare: Well-being from emotional perception to neuromodulation.

OBJECTIVE: This study aimed to demonstrate the specific nature of well-being induced by a facial skincare by deciphering its physiological and psychological impacts out of a therapeutic context. METHODS: Objective and subjective evaluations were performed on two groups of healthy participants. One group of 32 participants received 1-h facial skincare, while the second group of 31 participants were subjected to a resting condition during the same period. Electroencephalography, electrocardiography, electromyography, and respiratory rate measurements were assessed before and after both experimental conditions. Prosody and semantic analyses were also performed to evaluate the emotional perception in both groups. RESULTS: Physiological relaxation was observed after both experimental sessions; however, the effect was higher after the facial skincare. The cerebral, cardiac, respiratory, and muscular relaxation induced by facial skincare was 42%, 13%, 12%, and 17% higher, respectively, than that induced by the resting condition. In addition, non-verbal and verbal assessments showed that positive emotions were more markedly associated with the perception of facial skincare. CONCLUSION: The comparison between parameters recorded after a rest period allowed us to distinguish the physiological and psychological signature of facial skincare. Moreover, our results suggest an involvement of positive emotions in the physiological relaxation enhancement. All these observations contribute to the very scarce data available on the specific profile of well-being associated with facial skincare.

OBJECTIF: Cette étude visait à démontrer la nature spécifique du bien-être, induit par un soin du visage, en décryptant son impact physiologique et psychologique en dehors d'un contexte thérapeutique. MÉTHODES: Des évaluations objectives et subjectives ont été réalisées sur deux groupes de participants sains. Le premier groupe, de 32 participants, a reçu un soin du visage d'une heure ; tandis que le second groupe, de 31 participants, a été soumis à une session de repos de même durée. Des mesures d'électroencéphalographie, d'électrocardiographie, d'électromyographie, ainsi que de fréquence respiratoire, ont été enregistrées avant et après ces deux conditions expérimentales. Des analyses prosodiques et sémantiques ont également été effectuées, pour évaluer la perception émotionnelle dans chacun des deux groupes. RÉSULTATS: Une relaxation physiologique a été observée après les deux sessions expérimentales ; cependant, celle-ci fût plus importante après le soin du visage. En effet, comparativement à la session de repos, le soin du visage a induit une relaxation cérébrale, mais aussi cardiaque, respiratoire et musculaire, plus élevées de 42%, 13%, 12% et 17%, respectivement. De plus, les évaluations verbales et non verbales ont montré que les émotions positives étaient nettement plus associées à la perception du soin du visage, plutôt qu'à celle du repos. CONCLUSION: Cette étude comparative nous a permis de distinguer la signature physiologique, mais aussi psychologique, du soin du visage. Egalement, nos résultats suggèrent une implication des émotions positives dans l'amélioration de la relaxation physiologique. Ces observations contribuent à enrichir les rares données disponibles sur le profil spécifique du bien-être associé au soin du visage.

Qualitative and Quantitative Study of the Potential of Lipid Nanocapsules of One Hundred Twenty Nanometers for the Topical Administration of Hydrophobic Molecules.

In this study, we evaluated the potential of lipid nanocapsules (LNC) of 120 nm as drug nanocarriers to treat skin diseases. As a model molecule, we encapsulated the fluorescent dye curcumin, which also is an antioxidant. Curcumin-loaded LNC showed interesting antioxidant properties and a low toxicity on human skin cells. The penetration of curcumin in the skin was determined by 2 complementary methods: high performance liquid chromatography was used to measure total curcumin accumulation in the skin, whereas fluorescence confocal spectral imaging of skin sections showed that curcumin preferentially accumulates in the stratum corneum and the viable epidermis. These results confirm that LNC of a size above 100 nm can vectorize hydrophobic compounds to the keratinocytes without transdermal delivery. They also demonstrate the interest of combining 2 analytical methods when studying the skin penetration of nanovectorized molecules.

Effect of cosmetic ingredients as anticellulite agents: synergistic action of actives with in vitro and in vivo efficacy.

BACKGROUND: The pathophysiology of cellulite involves changes in the subcutaneous adipose layer and the extracellular matrix (ECM) that supports it together with overlying dermal layer. Cellular mechanisms governing cellulite are not fully understood. However, it is accepted that changes include enhanced lipogenesis, decreased lipolysis, and increased lipid storage within the adipocytes as well as changes in the dermal architecture. AIM: In our studies the ability of cosmetic agents Furcellaria lumbricalis, Fucus vesiculosus, retinoid, conjugated linoleic acid (CLA), and a glaucine mixture to stimulate in vitro 1) lipolysis in human adipocytes and 2) production of pro-collagen I by fibroblasts was investigated in vitro. The ability of these ingredients to improve cellulite condition in vivo was also determined. PATIENTS/METHODS: Mature adipocytes and 'aged' fibroblasts were used for in vitro studies. The assessment of cellulite in vivo was performed by dermatological grading and ultrasound measurements. RESULTS: Mature adipocytes treated with combined actives resulted in a significant synergistic increase in free glycerol release. On "aged" fibroblasts, combined treatment of F. vesiculosus and F. lumbricalis stimulated pro-collagen I production. CLA increased pro-collagen I production, but the glaucine mixture had no effect. The clinical study demonstrated a significant improvement in cellulite grading by a dermatologist after 8 and 12 weeks vs. vehicle, and ultrasound imaging showed a significant decrease in fat thickness compared with placebo after 12 weeks. CONCLUSIONS: Our studies revealed a potent cocktail of ingredients that when combined together can act in vitro to markedly improve lipolysis mechanisms and by way of stimulating pro-collagen I can also have an effect on the surrounding extracellular matrix. The in vitro actions of the ingredients were translated in vivo, where a clinical improvement of cellulite condition was observed.

Age-dependent response of energy metabolism of human skin to UVA exposure: an in vivo study by 31P nuclear magnetic resonance spectroscopy.

PURPOSE: The aim of our study was to evaluate the in vivo energy metabolism of human skin as a function of age, in conditions of rest and after a mild stress caused by a suberythemal UVA irradiation. METHODS: The kinetics of UVA-induced modifications in high-energy phosphorylated metabolites of young and old skins were non-invasively monitored over a period of 24 h using 31P nuclear magnetic resonance spectroscopy. In vivo 31P spectra were obtained on the ventral aspect of the wrist, using a NMR Imaging Spectrometer equipped with a double-tuned surface coil. Concentrations of phosphocreatine, inorganic phospate, adenosine tri-phosphate, phosphomono and phosphodiesters were calculated from the spectra and results were expressed as relative concentrations. A total of 20 subjects were enrolled in this study (n = 10 for the age group below 25 years and n = 10 for the age group above 55 years). A second experiment was then performed on 10 old subjects (mean age 60) who were treated on one wrist, twice a day for one month prior to UVA irradiation, with a product that contained active ingredients to restore barrier function and modulate the inflammatory response, the other wrist being an untreated control. RESULTS: Baseline levels of phosphorylated metabolites were similar in young and old skins. A suberythemal dose of UVA (6 J.cm-2) led to a significant decrease in the PCr/Pi ratio (index of energy status) and a significant increase in the PME/PDE ratio (index of cellular turnover rate of lipid-related metabolites) within 1 h. The observed variations were transient and the recovery was complete at T + 24 h post-UVA, although recovery was significantly slower in the older group. The disturbances were significantly reduced after treatment of the older skin with a formula that restored barrier function of the stratum corneum and modulated the inflammatory response. CONCLUSION: (i) baseline levels of energy metabolites in skin do not seem to vary with age; (ii) low dose UVA irradiation induces a rapid response in the energy metabolism of the skin; (iii) the kinetics of the response and recovery after an aggression by UVA suggest that older skin has significantly less energy rebound after a stress situation than younger skin; (iv) the energy reserve in older skin can be protected efficiently against UVA-induced stress by restoring barrier function and modulating the inflammatory response.