Articles & Publications

XXVI Congreso Latinoamericano e Ibérico de Químicos Cosméticos, Buenos Aires, 16-18 Abril 2023 G Facchini, GH Silva, BF Carli, GB Bidoia, G Leite, ALTA Pinheiro, AS Pinheiro, S Eberlin Introdução: A radiação infravermelha-A (rIV-A) é confirmada pela literatura como agravante do processo de envelhecimento cutâneo devido à indução de alterações fisiológicas que culminam desde desordens inestéticas até a formação de neoplasias malignas. A identificação de genes alvos dessa radiação na pele tornou-se uma ferramenta importante com o intuito de disponibilizar metodologias precisas para avaliação da eficácia de dermocosméticos na proteção contra os efeitos nocivos da rIV-A. Objetivo: Nesse sentido, o objetivo deste estudo foi investigar a modulação de genes envolvidos com as alterações funcionais promovidas pela rIV-A em explantes de pele humana (fragmentos ex vivo ) submetidos ao contato/uso de uma formulação cosmética. Métodos: Fragmentos de pele obtidos de cirurgia plástica eletiva foram submetidos ao contato/uso de uma formulação cosmética e expostos à rIV-A para posterior uma análise de expressão gênica em larga escala utilizando sistema Real Time qPCR (RT-qPCR) de microfluídica ( Integrated Fluidic Circuits ). Resultados: Inicialmente, a comparação entre a expressão gênica dos fragmentos irradiados e os fragmentos submetidos ao contato/uso de uma formulação cosmética indicou a modulação de 22 genes diferencialmente expressos. Especificamente, observou-se o enriquecimento de vias envolvidas com a síntese e montagem da matriz extracelular (ECM; como COL1A1, COL4A1 e FBN1), controle da resposta inflamatória (como IL-1β e IL-24), fatores de crescimento (como FGF2 e KRT19) e relacionados à função barreira da pele como diferenciação celular e hidratação da pele (KRT10, KRT2 e AQP3). Conclusões: A técnica de expressão gênica em larga escala, utilizando RT-qPCR por microfluídica demonstra ser uma abordagem acessível para triagem de alvos genéticos impactados por contato/uso de formulações cosméticas, sendo possível averiguar respostas relacionadas à síntese e manutenção da ECM, controle de inflamação, função barreira e crescimento e diferenciação celular.

XXVI Congreso Latinoamericano e Ibérico de Químicos Cosméticos, Buenos Aires, 16-18 Abril 2023 G Facchini, GH Silva, BF Carli, GB Bidoia, G Leite, ALTA Pinheiro, AS Pinheiro, S Eberlin Introdução: A radiação infravermelha-A (rIV-A) é confirmada pela literatura como agravante do processo de envelhecimento cutâneo devido à indução de alterações fisiológicas que culminam desde desordens inestéticas até a formação de neoplasias malignas. A identificação de genes alvos dessa radiação na pele tornou-se uma ferramenta importante com o intuito de disponibilizar metodologias precisas para avaliação da eficácia de dermocosméticos na proteção contra os efeitos nocivos da rIV-A. Objetivo: Nesse sentido, o objetivo deste estudo foi investigar a modulação de genes envolvidos com as alterações funcionais promovidas pela rIV-A em explantes de pele humana (fragmentos ex vivo ) submetidos ao contato/uso de uma formulação cosmética. Métodos: Fragmentos de pele obtidos de cirurgia plástica eletiva foram submetidos ao contato/uso de uma formulação cosmética e expostos à rIV-A para posterior uma análise de expressão gênica em larga escala utilizando sistema Real Time qPCR (RT-qPCR) de microfluídica ( Integrated Fluidic Circuits ). Resultados: Inicialmente, a comparação entre a expressão gênica dos fragmentos irradiados e os fragmentos submetidos ao contato/uso de uma formulação cosmética indicou a modulação de 22 genes diferencialmente expressos. Especificamente, observou-se o enriquecimento de vias envolvidas com a síntese e montagem da matriz extracelular (ECM; como COL1A1, COL4A1 e FBN1), controle da resposta inflamatória (como IL-1β e IL-24), fatores de crescimento (como FGF2 e KRT19) e relacionados à função barreira da pele como diferenciação celular e hidratação da pele (KRT10, KRT2 e AQP3). Conclusões: A técnica de expressão gênica em larga escala, utilizando RT-qPCR por microfluídica demonstra ser uma abordagem acessível para triagem de alvos genéticos impactados por contato/uso de formulações cosméticas, sendo possível averiguar respostas relacionadas à síntese e manutenção da ECM, controle de inflamação, função barreira e crescimento e diferenciação celular.

FarmaCosmética 2023, Bogotá, 08-10 March, 2023 - Poster. S Eberlin, G Facchini, GH Silva, VC Albarici, NCBS Ramos, AXP Dini, S Eberlin, ALTA Pinheiro, AS Pinheiro. La producción excesiva de radicales libres (RL) inducida por la radiación ultravioleta (UV) es uno de los principales mecanismos involucrados en el proceso de envejecimiento de la piel y anexos cutáneos. Comprender la relación de equilibrio entre la producción de RL y la neutralización favoreció el desarrollo de marcadores de daño oxidativo utilizando sistemas de prueba químicos o biológicos para evaluar la efectividad de las sustancias antioxidantes. Entre estos modelos se encuentran las mediciones del Factor de estado radical (RSF) y el Factor de protección radical (RP - Protección radical) que caracterizan y cuantifican todas las proteínas radicales presentes en un sistema de prueba. Estos son factores que evalúan el estado redox que es determinante para la aparición de cambios funcionales y estructurales. En este sentido, el objetivo de esta investigación fue evaluar la eficacia preclínica de productos cosméticos en la protección contra el estrés oxidativo inducido por la RUV mediante la medición de RSF y RP en cultivos de piel humana y en mechas de cabello. Para esto, fragmentos de piel humana obtenidos de cirugía plástica se incubaron con un producto cosmético durante 48 horas y se sometieron a RUV para la cuantificación posterior de RSF y RP. Paralelo a esto, mechas de cabello también fueron tratadas con un producto cosmético y expuestas a la RUV para cuantificación de RSF y RP. Nuestros resultados demostraron que los productos cosméticos evaluados promueven la reducción de la síntesis de proteínas radicales en la piel y el cabello, ejerciendo así un efecto protector contra la síntesis excesiva de RLs inducida por la exposición a la RUV. Por lo tanto, podemos inferir que los productos evaluados tienen un beneficio antioxidante, protegiendo la piel y la fibra capilar de los procesos oxidativos que culminan en importantes cambios funcionales y estructurales.

35 Congresso Brasileiro de Cosmetologia, São Paulo, 13-15 Junho 2023-Poster Albarici, V. C.; Ramos, N. C. B. S; Dini, A. X. P.; Ferreira, M. M.; Hercolino, C. V.; Ribeiro, N. A.; Gonçalves, V. P.; Pinheiro, A. S. Introduction: Hair fiber surface condition is one of the attributes that is firstly identified by consumers upon touching hair. The friction reduction is directly linked, microscopically, to the increase in softness on the fibers surface, which includes a decrease of roughness and the closure of cuticular layers. Macroscopically, it is also necessary that a lower degree of aggregation and interaction exist between fibers. Objective: The purpose was to assess the macro and microscopic hair surface characteristics of different ethnical origins utilizing the techniques of microscopy, combability and sound analysis. Materials and Methods: Natural hair tresses of straight, wavy, curly and kinky curvatures were used. The scanning electronic microscopy was realized on 5 fibers of each hair type. An equipment with electronic sensors that traduce fibers roughness on sound intensity was used. Combability measurements were conducted using the universal test equipment, in which the tresses were submitted to a passing through a fixed comb. Results and Discussion: According to the obtained results, the superficial hair fibers roughness showed equal mean values between the hair groups studied, i.e., the hair with different curvatures showed similar damage degree. The combability analyses showed a crescent energy with the increase of hair curvature. These results are corroborated with sound analyses, in which with the increase of hair curvature there is an increase of sound intensity, indicating a higher friction of fibers with the electronic sensors. Conclusions: The microscopic results analyzed showed that the natural hair of different curvatures showed similar roughness results. However, the macroscopic analysis demonstrated that the responses of energy to combing and sound intensity are also associated with the interaction between the fibers and their aggregation, being therefore, factors that impact the friction of the hair. Thus, it can be concluded that the combination of macroscopic and microscopic analysis is fundamental for a robust analysis of the surface conditions of the hair.

FarmaCosmética 2023, Bogotá, 08-10 March, 2023 - Poster. G Facchini, S Eberlin, GH Silva, Nogueira GV, ALTA Pinheiro, AS Pinheiro El estrato córneo (EC) está colonizado por una amplia gama de microorganismos y esta población microbiana se conoce como microbiota o microbioma cutáneo. Esta población específica está formada por bacterias, hongos, levaduras y virus, que habitan simbióticamente la piel y sus anexos. Varios factores pueden desequilibrar la composición de la microbiota de la piel y favorecer desde el inicio de trastornos cutáneos transitorios como la xerosis y la hiperborrea, hasta afecciones crónicas como la dermatitis atópica y seborreica. En este sentido, presentamos en este trabajo una recopilación de herramientas capaces de evaluar la acción de activos y formulaciones cosméticas en la modulación de la microbiota cutánea, ya sea en la piel, el cuero cabelludo o las membranas mucosas, y proporcionar productos con propiedades prebióticas, probióticas o simbióticas. Los protocolos clásicos de cultivo, análisis y caracterización de microorganismos, como el recuento de colonias, la zona de inhibición y la formación de biopelículas, se han utilizado para evaluar apelaciones como desodorante, anticaspa, humectante, seborregulatorio, antiacné, entre otros. Además, las técnicas avanzadas para identificar la microbiota cutánea, como la secuenciación ribosómica 16s o 18s y el análisis de porfirina mediante el sistema fotográfico Visia®, han demostrado ser herramientas valiosas para la evaluación clínica de la acción moduladora de los productos cosméticos en la flora cutánea. Más recientemente, hemos implementado un modelo que mide indirectamente la respuesta biológica de la piel a los subproductos microbianos. Estos modelos están a la vanguardia de la tecnología y son un recurso prometedor para evaluar los efectos de los productos en la armonización de microbiomas, la homeostasis inmune, la bioestimulación de las defensas naturales de la piel y el mantenimiento de las características saludables de la piel.

XXII Congresso Brasileiro de Toxicologia, Balneário Camboriú-SC, 25-28 Maio 2022. Camila Martins Kawakami, Gustavo Henrique da Silva, Kézia Moura, Ana Lúcia Tabarini Alves Pinheiro, Adriano da Silva Pinheiro, Samara Eberlin, Lorena Rigo Gaspar, Thais Fuzinaga, Eduardo Vicente, Gustavo Facchini. The recent scenario of COVID-19 has resulted in an increase in hand cleansing products such as soaps, synthetic detergents, antiseptic handwashes, and alcohol-based hand sanitizers. Consequently, an emergence of several skin conditions including irritant contact dermatitis (ICD) and allergic contact dermatitis (ACD) due to excessive personal hygiene measures has been observed. These skin problems may result from a cascade of events involving cell damage, inflammatory responses, cytokine release, and activation of dendritic and T-cells; the latter being a key biological event underlying skin sensitization. Chlorhexidine is an effective antiseptic agent widely used in cosmetics, hospital products, and medicines. Although clinical studies on chlorhexidine are common, the in vitro assessment and the molecular mechanisms involved in irritant and allergic contact dermatitis are rarely reported. This study aimed to evaluate the skin irritation and skin sensitization potential of a commercial formulation containing the antiseptic chlorhexidine (1%) by in vitro methods. The skin irritation potential was evaluated according to OECD TG 439 through the determination of cell viability in ex vivo human skin fragments using the vital dye MTT. Additionally, the inflammatory cytokine IL-1α was quantified. For skin sensitization assessment, the in chemico direct peptide reactive assay (DPRA) was performed following OECD TG 442C, which evaluates the cysteine- or lysine-containing peptide depletion using high-performance liquid chromatography (HPLC). Skin sensitization was also evaluated using the human cell line activation test (h-CLAT, OECD TG 442E), which quantifies changes in cell surface marker expression (CD86 and CD54) on a human monocytic leukemia cell line (THP-1 cells), using flow cytometry. The results of skin irritation (OECD TG 439) demonstrated that the positive control LSS (5%) was considered irritant since it reduced cell viability by more than 50% compared to the non-treated control. On the other hand, the product containing chlorhexidine (1%) was classified as non-irritant, as it presented cell viability of approximately 73.55%. In addition, treatment with the product assessed did not promote a significant increase in the inflammatory cytokine IL-1α release compared to the baseline control. The in chemico DPRA assay demonstrated that, as expected, the positive control dinitrochlorobenzene (DNCB) presented a positive prediction for skin sensitization. The ingredient and the product assessed also presented a positive prediction for skin sensitization (low reactivity) according to OECD TG 442C. Finally, the results from the h-CLAT assay showed that the positive control DNCB presented relative fluorescence intensities (RFI) ≥ 150 for CD86 and ≥ 200 for CD54, which classifies this substance as sensitizing according to OECD TG 442E. Moreover, the product containing chlorhexidine (1%) also presented sensitizing potential since the RFI for CD86 was above the acceptable value for non-sensitizing substances (ongoing experiment). The results showed that the product containing chlorhexidine (1%) did not present potential for skin irritation. In addition, it demonstrated positive prediction for skin sensitization potential in both in chemico DPRA and in vitro h-CLAT assays. Further studies should be conducted with this hand hygiene product category to better understand the molecular mechanisms involved in irritant and allergic contact dermatitis.

32 nd IFSCC Congress (International Federation of Societies of Cosmetic Chemists), London, 19-22 September, 2022. Ana Paula Fonseca, Carine Dal Pizzol, Samara Eberlin, Antonio Carlos Vanzo, Patricia M. B. G. Maia Campos. The application of antioxidants in cosmetic products contributing to collagen preservation and synthesis, acting in melanogenesis, and improving overall skin health and appearance is advancing. Thus, the objective of this study was to evaluate the efficacy and safety of a cosmetic formulation containing a blend of ingredients, such as nano ascorbyl palmitate, nano resveratrol, tocopherol, nano caffeine, carnosine, and niacinamide by ex vivo and clinical evaluations. The in vitro tests were performed through the measurement of mitochondrial reactive oxygen species (mROS) in human fibroblast cell culture after IR-A radiation and after IR-A plus treatment with the investigational product (IP). After the approval of the Ethics Committee, measurements of melanin, type 1 procollagen were performed in ex vivo human tissue from elective plastic surgery after UV radiation and after radiation plus the cosmetic treatment. In addition, filaggrin was also measured in ex vivo human tissue, but this time after skin barrier rupture with SLS 5% and after this rupture plus investigational product treatment. Finally, a clinical study was performed by instrumental measurements to evaluate skin hydration (Corneometer), skin oiliness (Sebumeter), collagen synthesis with diffuse reflection spectroscopy (DRS), and swelling around the eyes using the Vectra XT imaging system. For this, after the approval of the Ethics Committee, 20 healthy females aged 40 to 50 years old, Fitzpatrick phototype II, III, and IV were recruited. In addition, a self-assessment questionnaire was applied to evaluate perceived efficacy by study participants. Safety and tolerance studies were also carried out with the product under use, as well as acne lesions count on the skin by an investigator dermatologist. The in vitro study showed that the product statistically (p<0.001) decreased mROS by -73.13% at 10.01 mg/ml; -64.58% at 3.17 mg/ml and -59.88% at 1 mg/ml. The ex vivo study showed that the product statistically (p<0.001) decreased melanin pigmentation by 81.53% in the irradiated and treated group when compared to the only irradiated group. Furthermore, the product statistically (p<0.001) increased type 1 procollagen by 260.40%, compared to the only irradiated group. Also, a significant (p<0.05) increase in filaggrin production was observed when compared to the SLS ruptured and untreated group. The clinical study results showed a significant (p<0.001) decrease in skin superficial oiliness after 1 and 4 hours of IP application, compared to the control area (non-treated) and a significant (p<0.001) increase in the dielectric constant after 1, 4, 8, 12, and 24 hours of product application compared to the non-treated area, suggesting an increase in the stratum corneum water content. There was no adverse event, physical sign, or reported sign, showing that the studied cosmetic product presents a high tolerance profile on normal skin. The acne lesion count presented a significant decrease in non-inflammatory lesions (p= 0.0135) and a non-significant reduction in inflammatory lesions (p=0.6641). DRS results analysis showed a significant increase (p<0.05) in the values of I340/I295 (collagen/tryptophan) after a 56 and 84-day period of treatment, suggesting an increase in collagen synthesis on facial skin. The Vectra XT imaging analysis showed that the cosmetic product promoted a significant (p<0.05) reduction in the swelling around the eyes in 95% of subjects after 1 hour of application and after 14 and 28 days of daily use in 100% of subjects (p<0.05). Finally, 120 subjects answered the self-assessment questionnaire, and the product was well appreciated by them: 91% reported their skin was softer, 83% noticed an improvement in the skin's overall appearance, and 93% in skin hydration. The proposed cosmetic product was safe and effective in improving skin conditions and appearance by increasing collagen synthesis, resulting in firmer, less rough, softer, and smoother skin. The reduction of melanin and increase in filaggrin suggest a diminishment in blemishes and more hydrated skin, as shown by Corneometer measurements. In addition, the product was effective for application on oily skin since it reduced the superficial sebum amount and can act in controlling skin hydrolipid balance. In the clinical evaluation, study participants also perceived the improvement in skin hydration and smoothness observed in instrumental measurements. Finally, the present study has an important contribution since it showed the benefits of a cosmetic product based on nanoencapsulated antioxidants using different and innovative evaluation methods.

Surgical and Cosmetic Dermatology 2022, 14e20220118. ISSN-e 1984-8773. DOI: 10.5935/scd1984-8773.2022140118. Brayan Styven Merchan Rojas, Jose Luis De-la-hoz, Gustavo Facchini, Gustavo Henrique da Silva, Ana Lucia Tabarini Alves Pinheiro, Samara Eberlin. Plant extracts and actives derived from plants were developed to improve and enhance the skin healing process, including Triticum aestivum L. (Triticum vulgare). To evaluate the effect of whole grain extract (EGTA-PR) and aqueous extract (EATA-FI) of Triticum aestivum L., on ex vivo skin healing, skin fragments obtained from elective plastic surgery were subjected to tissue damage and treated with extracts for eight days for histological evaluation of re-epithelialization and immunofluorescence for epidermal growth factor (EGF). EGTA-PR and EATA-FI accelerated the re-epithelialization process in human skin culture submitted to tissue injury. Additionally, we observed increased EGF protein labeling after treatment with EGTA-PR. EGTA-PR showed a better performance in re-epithelialization when compared to EATA-FI, as it presented a higher protein labeling for EGF in human skin culture. Likewise, the histological results showed that the dermal redensification obtained with EGTA-PR was visually superior to that observed with EATA-FI. The results obtained are promising and corroborate the several biological actions already reported in the literature for Triticum aestivum L. extract in tissue healing stages.

Arte y Ciencia Cosmética 2021, 33(80): 30-45 ISSN 0122-8072. Samara Eberlin, Gustavo Facchini, Gustavo Henrique da Silva, Ana Lúcia Tabarini Alves Pinheiro, Samir Eberlin, Adriano da Silva Pinheiro. El desarrollo de métodos alternativos para las pruebas de seguridad y eficacia que eviten el uso de animales es una tendencia mundial, que se basa en la mejora de los modelos y herramientas actuales para que reproduzcan mejor la biología humana. La piel humana proveniente de cirugías plásticas electivas es un modelo experimental prometedor para probar los efectos de los productos de uso tópico. Como se mantiene la estructura de la piel nativa, incluida la población celular (queratinocitos, melanocitos, células de Langerhans y fibroblastos) y la matriz dérmica (que contiene colágeno, elastina, glicosaminoglicanos, etc.), es la que más se acerca a los efectos de las sustancias en la piel humana in vivo. En esta revisión, presentamos una colección de resultados que nuestro grupo ha generado a lo largo de los últimos años, implicando el uso de explantes de piel y cuero cabelludo humanos, demostrando la viabilidad de este modelo. El desarrollo de un sistema de prueba con explantes de piel ex vivo, de tamaño y grosor estándar, y cultivados en la interfaz aire-líquido, puede proporcionar una herramienta importante para comprender los mecanismos implicados en varios trastornos cutáneos.

Journal of Dermatology and Dermatitis 6(2), 2021 DOI: 10.31579/2578-8949/078 Samara Eberlin, Liliana Torloni, Angélica Richart Csipak, Gustavo Facchini, Gustavo H. Silva, Camila Martins Kawakami, Ana L. T. A. Pinheiro, Vivienne Carduz Castilho. People suffering from an ordinary acute cold use so many handkerchiefs that the wiping actions alone increase the abrasive damage of the nasolabial zone, finally leading to a disturbed barrier function and inflammation. It seems that the quality of the material used for nose cleansing could play an important role, and that innovative handkerchiefs could fulfill a preventive role in minimizing the damaging effects on the skin barrier function of the nasolabial zone during these conditions. The objective of this work was to evaluate the effects of a wet handkerchief (SKNW) on the skin barrier balance by measuring filaggrin and histamine using an experimental model of ex vivo native human skin and the interference of this handkerchief in the skin microbiota through in vitro screening. SKNW showed an increase in the production of filaggrin and a reduction in histamine synthesis in human explants subjected to barrier disruption with 5% Sodium Lauryl Sulfate. Additionally, SKNW showed mild to moderate antiseptic action on the evaluated microorganisms. This study demonstrated that SKNW could be considered a feasible option for consecutive wiping of the nasolabial zone, avoiding transient mechanical dermatitis, considering its skin barrier protective, non-irritating, and antiseptic actions.

Eberlin S, Facchini G, Pinheiro ALTA, Buzalaf MAR, Leite AL, Eberlin S, Pinheiro AS. Cosmetics & Toiletries (Brasil), Vol. 33(6), nov-dez 2021, 14-17. O envelhecimento capilar é um processo multifatorial influenciado principalmente por fatores ambientais. Neste estudo, investigamos os efeitos nocivos da radiação UV no couro cabeludo humano, por meio da análise proteômica, com o propósito de eleger estratégias farmacológicas para a manutenção da saúde dos folículos e das fibras capilares. Hair damage is a multifactorial process influenced mainly by environmental factors. In this study, we investigated the harmful effects of UV radiation on the human scalp through proteomic analysis, with the purpose of choosing pharmacological strategies.

Alternatives to Laboratory Animals 2021. DOI: 10.1177/02611929211038652. Eberlin S, Facchini G, Henrique G, Eberlin Samir, Bragatto A, Tabarini A, Pinheiro A. Native human skin has been reported in the literature as being an important experimental model for studying skin biology. Studies performed by our group have shown that ex vivo skin, from elective plastic surgery, maintains the biological characteristics of native skin under specific culture conditions. As such, it might be a feasible model for the safety and efficacy testing of topical substances. While Brazil is at the forefront of global regulation implementation, Brazilian researchers are not always able to transfer certain widely used protocols to their laboratories, particularly protocols that involve the use of reconstructed tissues with limited viability, such as those for skin corrosion (OECD TG 431) and irritation testing (OECD TG 439). In this study, we investigated the applicability of the ex vivo skin model to the evaluation of irritation and corrosion potential of a number of proficiency substances described in TG 431 and TG 439. The skin fragments were standardised in size and diameter, and placed into cell culture inserts. The experimental protocol was conducted according to TG 431 and TG 439. The results obtained show that ex vivo skin could represent a promising tool for the evaluation of irritation and corrosion potential of substances (subject to inclusion and exclusion criteria), as recommended by OECD guidelines. While this is a proof-of-concept study, the use of ex vivo skin should be considered for such testing. Link to article: https://journals.sagepub.com/doi/pdf/10.1177/02611929211038652

Journal of Cosmetic Dermatology 2021. DOI: 10.1111/jocd.14202. Ayres EL, Silva JS, Eberlin S, Facchini G, Vasconcellos C, Costa A. French maritime pine bark (Pinus pinaster) extract (PBE), the registered trade name of which is Pycnogenol®, has been studied for its depigmenting action due to its antioxidant, anti-inflammatory, and anti-melanogenic activity. However, the mechanisms through which PBE are still not fully clear. Objective: Evaluate the impact of PBE on four in-vitro parameters closely associated with cutaneous pigmentation, including melanin synthesis, tyrosinase activity, endothelin-1 (ED1) and production of peroxisome proliferator-activated receptor ?, ?, and ? (PPAR ?, ?, and ?), by studying the modulation of action of ultraviolet radiation A (UVA)/ultraviolet radiation B (UVB), infrared-A (IR-A), visible light (VL), and association of UVA/UVB, IR-A, and VL (ASS). Methods: Human melanocytes were incubated in a dry extract solution of PBE, exposed to UVA/UVB, IR-A, VL, and ASS for subsequent quantification of melanin, ED1, and PPAR ?, ?, and ?. The effects of PBE on inhibition of tyrosinase activity were also performed by monophenolase activity assay. Results: UVA/UVB, IR-A, VL, and ASS radiation caused significant increases in the synthesis of melanin, ED1, and PPAR ?, ?, and ? when compared to baseline control. However, PBE significantly reduced the production of melanin, ED1, and PPAR ?, ?, and ?, as well as reducing about 66.5% of the tyrosinase activity. Conclusions: PBE reduces in vitro melanin production by downregulating tyrosinase and reducing pigmentation-related mediators, such as ED1 and PPAR ?, ?, and ?, therefore contributing to the inhibition of pathways associated with skin hyperpigmentation.

Journal of the American Academy of Dermatology, 83(6) Supplement 1, AB161, 2020. DOI: http://dx.doi.org/10.1016/j.jaad.2020.06.734 Samara Eberlin, Gustavo Facchini, Michelle Sabrina da Silva, Gustavo Henrique da Silva, Ana Lúcia Tabarini Alves Pinheiro, Adilson Costa. Atopic dermatitis (AD) is a chronically relapsing inflammatory disease associated with genetic predisposition and environmental factors. Altered immune response and skin barrier dysfunction are mainly responsible for the onset of skin lesions characterized by severe itching. Affected patients are highly sensitized to house dust mites, such as Dermatophagoides farinae (DF), which is considered a common environmental allergen causing AD. Among the abnormalities in the epidermal barrier, changes in the lipid profile of the stratum corneum are highlighted, with the most notable feature being the decrease in ceramide levels. In addition, there is a reduction in the levels of envelope proteins filaggrin, involucrin, and loricrin. An ex vivo AD model was developed using skin fragments obtained from elective plastic surgery and subjected to epidermal barrier disruption with 4% sodium lauryl sulfate. Additionally, the skin was exposed to DF extract for two consecutive days. Skin fragments were collected, fixed, and cryopreserved for immunofluorescence evaluation of filaggrin, involucrin, loricrin, and sphingomyelin synthase. Our results revealed that the human experimental AD model was able to satisfactorily mimic skin characteristics of AD by significantly reducing the filaggrin, involucrin, and loricrin labeling when compared to the control group. Labeling for sphingomyelin synthase - which is directly related to ceramide synthesis - also dropped considerably. Fragments of ex vivo human skin constitute the experimental model that most closely approximates real conditions for evaluating the efficacy and safety of topically applied products. These findings strongly suggest that this model can be useful not only for elucidating AD pathogenesis but also for evaluating novel therapeutic agents.

Samara Eberlin, Farmacéutica, Magíster en Fisiopatología Médica y Doctorado en Farmacología, Facultad de Ciencias Médicas - UNICAMP Link para el artículo