Spirulina, Palmaria Palmata, Cichorium Intybus, and Medicago Sativa extracts in cosmetic formulations: an integrated approach of in vitro toxicity and in vivo acceptability studies.

Background/Aims: The selection of suitable raw materials in the cosmetic research and development is a key point, not only in order to obtain the expected results but also to avoid undesirable side effects. This study evaluated the in vitro toxicity potential of four different plant extracts and their in vivo acceptability studies. Methods: Spirulina, Palmaria palmata, Cichorium intybus and Medicago sativa extracts were analysed alone or in combination and added in cosmetic formulations. The in vitro toxicity evaluation, Hen's Egg Chorioallantoic Membrane Test (HET-CAM) and 3T3 NRU phototoxicity test were performed to evaluate in vitro potential ocular irritation and photo safety, respectively. Twenty subjects were enrolled in the acceptability studies, who were evaluated for the absence of harmful effects of the formulation by visual assessment and by transepidermal water loss, a biophysical technique, for 30 days. Results: HET-CAM assay showed that the studied extracts added to a gel-cream formulation had no irritant potential. In addition, the combination of Palmaria palmata, alfalfa and chicory extracts did not show phototoxic potential in vitro. Acceptability studies showed that the formulation containing the four extracts combined did not provoke any transepidermal water loss (TEWL) alteration, sensory irritation or erythema in the forearms for the period of analysis. Conclusion: The studied active ingredients, alone or in combination, present no cytotoxicity potential and when added to a gel-cream formulation had no irritant potential in vitro. These results predicting no harmful effects were confirmed in the acceptability tests, which showed no alteration on skin barrier function and no report of irritation perception of sign of erythema, suggesting the potential of these extracts for the development of safe cosmetic products.

Impacts of sun protection and skin care habits in the biophysical and morphological properties of young men skin.

BACKGROUND: Previous studies have demonstrated that UVB radiation may cause changes in the epidermal permeability barrier and in the stratum corneum hydration. It is also well known that sun exposure causes erythema, skin cancer, and other physiologic alterations. Furthermore, because of the cultural barrier, men usually apply less sunscreen. AIMS: The objective of this study was to evaluate the cosmetic use and sun protection habits of young men, correlating their lifestyle with the biophysical and morphological skin characteristics, as well as to study how skin unprotected sun exposure can affect these features even in young people. PATIENTS/METHODS: 60 participants between 18 and 28 years old were divided into two groups: with photoprotection habits (PP habits) and without photoprotection habits (No PP habits). They were questioned about their sunscreen and cosmetic products use. The skin parameters were evaluated using biophysical and skin imaging techniques. RESULTS AND CONCLUSION: 60% of the participants did not apply sunscreen often, and 80% did not consume other skin care products. No PP habits group presented an increase in the transepidermal water loss-TEWL and sebum level, as well as a reduction in the stratum corneum water content and dermis echogenicity. The skin characteristics evaluated in this study were correlated with the sun protection habits and skin care behavior showing that men face some sociocultural barrier to start the use of cosmetic products. Thus, it is important to consider this information for the dermatological clinical and development of cosmetic products for men's skin.

Corrigendum: Use of Advanced Imaging Techniques for the Characterization of Oily Skin.

[This corrects the article DOI: 10.3389/fphys.2019.00254.].

Use of Advanced Imaging Techniques for the Characterization of Oily Skin.

Excessively oily skin leads to clinical signs that cause discomfort to patients, such as excessive shine, enlarged pores, acne, and an imbalance of the hydrolipidic layer. In this context, a constant demand for the research and development of products that prevent these features, has been noted in the field of cosmetics and dermatology. Thus, the objective of this study is to evaluate the cutaneous characteristics of oily skin due an excessive production of sebum through biophysical and skin imaging techniques. 19 participants with different skin types were selected and the following parameters were evaluated: pore count, determination of the number of sebaceous glands and amount of sebum in infundibulum, determination of cutaneous microrelief, count of comedones, evaluation of epidermis thickness, characterization of the cellular, and comedone size and its characteristics. These evaluations were done through biophysical and skin imaging techniques. The obtained results showed that different regions of the face presented different characteristics related to oiliness, quantity, and the appearance of pores and comedones. The malar region had a lower epidermis thickness and a larger number of large pores. Moreover, in this region excessive sebum production, which can be related to pores, not comedones, was noted. The nose region presented higher sebum content in the infundibulum and lower active sebaceous glands, showing a higher activity of sebaceous production in this region. The chin region presented a positive correlation between the sebum content, roughness parameter and the number of pores and comedones. As different skin properties are related and influence the appearance of undesirable clinical signs, we identified the need for a multifactorial approach for the effective treatment of oily skin. The rational development of multifunctional cosmetic products that promote the control of oily skin, that regulate the keratinization process, improve the microrelief and leads to a better epidermis and dermis structure, will not only improve oily skin conditions but will also allow for the reduction or disappearance of clinical signs that result from excessive oiliness, all of which causes concern and results in a relentless search for cosmetic and dermatological products that address the unaesthetic nature of these conditions.