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.

Synthesis of nano-hematite for possible use in sunscreens.

Hematite nanoparticles were synthesized for ultraviolet filtration application by the precipitation method followed by calcination at different temperatures. A range of crystallite sizes between 37 and 85 nm (as determined by the Scherrer formula) was obtained, according to the temperature used for the calcination. An increase in the absorbance with increasing crystallite size was observed over the whole ultraviolet B and A range. The experimental band gap was 2.94 eV for the sample calcined at 500 degrees C and 3.08 eV for the sample calcined at 300 degrees C. The in vitro sun protection factor and protection factor-ultraviolet A of a water-in-oil emulsion made with the sample calcined at 500 degrees C as active ingredient were 9.21 and 8.81, respectively, which is higher than the protection factor-ultraviolet A values obtained for titanium dioxide and zinc oxide at the same mass concentration. The emulsion was found to be photostable.

Quercetin and rutin as potential sunscreen agents: determination of efficacy by an in vitro method.

Given that flavonoids are known for their ultraviolet (UV)B photoprotective properties in plants that contain them, we chose to study quercetin (1) and rutin (2) as agents that could potentially be used in sunscreen products. These two substances proved to behave in similar ways. When incorporated in oil-in-water emulsions, at a concentration of 10% (w/w), 1 and 2 give sun protection factor (SPF) values similar to that of homosalate, a standard substance. These two flavonoids also provided a non-negligible level of photoprotection in the UVA range. When used in association with titanium dioxide, the SPF obtained was around 30.

Foundations and self-tanning products: Do they provide any protection from the sun?

As soon as the weather turns sunny, everyone wants a tan. People with skin phototypes III and IV, called melanocompetent, have no problem meeting this fashion requirement. But things are quite different for people with phototypes I and II and so these individuals look for alternative solutions. In essence, light skin burns easily when exposed to the sun. Therefore, light-skinned people are offered a cosmetic solution through self-tanning products or foundations. It seemed interesting to us to evaluate the sun protection power of this type of product. To do this, we used an in vitro method to determine the typical indicators related to sunscreen products, such as sun protection factor (SPF), ultraviolet (UV)-A protection factor (PF-UVA), UV-B/UV-A ratio as well as the critical wavelength because these artificial tanning products could be considered sunscreen products by users. It is important to know whether a self-tanning product and/or a foundation provide sun protection and whether they meet the standards set for other sunscreen products. Protection which is imbalanced for either UV-B or UV-A radiation is potentially harmful for users believing themselves adequately protected. To do this, we assembled the requisite conditions for forming melanoidins in the cosmetic itself. We tested seven amino acids found in the corneal cells of the epidermis. Regardless of the amino acid used, the corresponding SPF was essentially zero (approximately SPF 2). Foundations, on the other hand, proved to be much more interesting because they possess a non-negligible SPF as well as good photostability making these products safe in terms of their mode of application (applied once daily).

Flavonoids and polyphenols, molecular families with sunscreen potential: determining effectiveness with an in vitro method.

The numerous uses and properties of flavonoids are well known, in particular their antioxidant, cancer-control and antiinflammatory effects. These properties can be used to enrich the field of topically-applied sun protection. The aim of the study was to determine the effectiveness of various flavonoids and polyphenols. We have used an in vitro method based on the transmittance measurement after spreading an oil in water emulsion containing either flavonoids or polyphenols on polymethylmetacrylate plates. Chlorogenic acid and apigenin were the best UV-filter and UVA-filter, respectively. The flavonoids and polyphenols studied are good candidates for us e in photoprotective products.

Interest of ferulic acid ethyl ester in photoprotective creams: measure of efficacy by in vitro method.

Topical sunscreens have been used for many years on exposed areas to protect the skin from the damaging effects of ultraviolets. If the sunscreens were essential, it is suggested that they have adverse effects. We chose to study ferulic acid ethyl ester (FAEE) as agent which could potentially be used in sunscreen products. FAEE was incorporated at various concentrations into O/W emulsions. Total of 30 mg of product exactly weighed were spread on poly(methylmethacrylate) plates over the whole surface (25 cm(2)). So, sun protection factor (SPF) and PF-UVA of the creams were measured in vitro. Transmission measurements between 290 and 400 nm were carried out using a spectrophotometer equipped with an integrating sphere. Incorporated in O/W creams, at a concentration of 10%, FAEE give a SPF similar to that of benzymidazilate, a filter permitted in EU.