Immediate and long-term effects of polysaccharides-based formulations on human skin

A new trend in cosmetic formulations is the use of biotechnological raw materials as the polysaccharides from Klebsiella pneumoniae, which are supposed to enhance cell renewal, improve skin hydration and micro-relief. Botanical extracts of Myrtus communis leaves contain different sugars, which may provide the same benefits. Thus, the objective of this study was to evaluate through objective and subjective analysis the immediate and long-term effects of cosmetic formulations containing polysaccharides biotechnologically-originated and / or the ones contained in Myrtus communis extracts. Three polysaccharide-based and placebo formulations were applied on the forearm skin of 40 volunteers. Skin hydration, transepidermal water loss (TEWL), viscoelasticity and skin micro-relief measurements were made before and 2 hours after a single application and after 15 and 30 day-periods of daily applications. Answers to a questionnaire about perceptions of formulation cosmetic features constituted the subjective analysis. All polysaccharide-based formulations enhanced skin hydration. Formulations with isolated or combined active substances improved skin barrier function as compared to placebo, in the short and long term studies. Formulations containing Myrtus communis extracts had the highest acceptance. Results suggest that daily use of formulations containing these substances is important for protection of the skin barrier function.Uma nova tendência em formulações cosméticas é a utilização de matérias-primas biotecnológicas como os polissacarídeos de Klebsiella pneumoniae, que pode aumentar a renovação celular e melhor a hidratação e micro-relevo da pele. Por outro lado, o extrato vegetal de Myrtus communis contém diferentes polissacarídeos, que também podem proporcionar benefícios à pele. Assim, o objetivo do estudo foi a avaliação dos efeitos imediatos e em longo prazo, de formulações cosméticas contendo polissacarídeos obtidos por processo biotecnológico e/ou de extrato de M. communis por meio de análises objetivas e subjetivas. Três formulações contendo os polissacarídeos e um placebo foram aplicadas na pele dos antebraços de 40 voluntários. As medidas foram realizadas antes e após 2 horas da aplicação das formulações e após 15 e 30 dias de aplicações diárias em termos de hidratação da pele, perda transepidérmica de água (TEWL), viscoelasticidade e micro-relevo da pele. Para a análise subjetiva, os voluntários responderam um questionário a fim de obter-se informações sobre a percepção relativa à qualidade de cosméticos. Todas as formulações provocaram aumento da hidratação cutânea. As formulações que continham os polissacarídeos melhoraram a função barreira da pele, em curto e em longo prazo. A formulação contendo extrato de M. communis apresentou maior aceitação. Os resultados sugerem que o uso diário dos polissacarídeos avaliados é importante na proteção da função barreira da pele

Immediate and long-term effects of polysaccharides-based formulations on human skin

A new trend in cosmetic formulations is the use of biotechnological raw materials as the polysaccharides from Klebsiella pneumoniae, which are supposed to enhance cell renewal, improve skin hydration and micro-relief. Botanical extracts of Myrtus communis leaves contain different sugars, which may provide the same benefits. Thus, the objective of this study was to evaluate through objective and subjective analysis the immediate and long-term effects of cosmetic formulations containing polysaccharides biotechnologically-originated and / or the ones contained in Myrtus communis extracts. Three polysaccharide-based and placebo formulations were applied on the forearm skin of 40 volunteers. Skin hydration, transepidermal water loss (TEWL), viscoelasticity and skin micro-relief measurements were made before and 2 hours after a single application and after 15 and 30 day-periods of daily applications. Answers to a questionnaire about perceptions of formulation cosmetic features constituted the subjective analysis. All polysaccharide-based formulations enhanced skin hydration. Formulations with isolated or combined active substances improved skin barrier function as compared to placebo, in the short and long term studies. Formulations containing Myrtus communis extracts had the highest acceptance. Results suggest that daily use of formulations containing these substances is important for protection of the skin barrier function.Uma nova tendência em formulações cosméticas é a utilização de matérias-primas biotecnológicas como os polissacarídeos de Klebsiella pneumoniae, que pode aumentar a renovação celular e melhor a hidratação e micro-relevo da pele. Por outro lado, o extrato vegetal de Myrtus communis contém diferentes polissacarídeos, que também podem proporcionar benefícios à pele. Assim, o objetivo do estudo foi a avaliação dos efeitos imediatos e em longo prazo, de formulações cosméticas contendo polissacarídeos obtidos por processo biotecnológico e/ou de extrato de M. communis por meio de análises objetivas e subjetivas. Três formulações contendo os polissacarídeos e um placebo foram aplicadas na pele dos antebraços de 40 voluntários. As medidas foram realizadas antes e após 2 horas da aplicação das formulações e após 15 e 30 dias de aplicações diárias em termos de hidratação da pele, perda transepidérmica de água (TEWL), viscoelasticidade e micro-relevo da pele. Para a análise subjetiva, os voluntários responderam um questionário a fim de obter-se informações sobre a percepção relativa à qualidade de cosméticos. Todas as formulações provocaram aumento da hidratação cutânea. As formulações que continham os polissacarídeos melhoraram a função barreira da pele, em curto e em longo prazo. A formulação contendo extrato de M. communis apresentou maior aceitação. Os resultados sugerem que o uso diário dos polissacarídeos avaliados é importante na proteção da função barreira da pele

Skin Irritation Testing beyond Tissue Viability: Fucoxanthin Effects on Inflammation, Homeostasis, and Metabolism

UV light catalyzes the ozone formation from air pollutants, like nitrogen oxides. Since ozone reacts with cutaneous sebum lipids to peroxides and, thus, promotes inflammation, tumorigenesis, and aging, even broad-spectrum sunscreens cannot properly protect skin. Meanwhile, xanthophylls, like fucoxanthin, proved their antioxidant and cytoprotective functions, but the safety of their topical application in human cell-based models remains unknown. Aiming for a more detailed insight into the cutaneous fucoxanthin toxicity, we assessed the tissue viability according to OECD test guideline no. 439 as well as changes in inflammation (IL-1α, IL-6, IL-8), homeostasis (EGFR, HSPB1) and metabolism (NAT1). First, we proved the suitability of our 24-well-based reconstructed human skin for irritation testing. Next, we dissolved 0.5% fucoxanthin either in alkyl benzoate or in ethanol and applied both solutions onto the tissue surface. None of the solutions decreased RHS viability below 50%. In contrast, fucoxanthin ameliorated the detrimental effects of ethanol and reduced the gene expression of pro-inflammatory interleukins 6 and 8, while increasing NAT1 gene expression. In conclusion, we developed an organ-on-a-chip compatible RHS, being suitable for skin irritation testing beyond tissue viability assessment. Fucoxanthin proved to be non-irritant in RHS and already showed first skin protective effects following topical application

Benefits of Combinations of Vitamin A, C and E Derivatives in the Stability of Cosmetic Formulations

Chemically stable ester derivatives of vitamins A, C and E have become a focus of interest for their role in the satisfactory results in skin aging treatments. Accordingly, the aim of this study was to evaluate the physical and chemical stability of a cosmetic formulation containing 1% retinyl palmitate, ascorbyl tetraisopalmitate and tocopheryl acetate, alone or in combination. In the studies of physical stability, a Brookfield rheometer was used to determine rheological behavior of formulations containing the vitamins. Chemical stability was determined by HPLC on a Shimadzu system with UV detection. Results showed that formulations had pseudoplastic behavior and that vitamins did not alter their apparent viscosity and thixotropy. In the chemical stability studies, first-order reaction equations were used for determinations of the shelf-life of vitamins derivatives considering a remaining concentration of 85%. Combined vitamins in a single formulation had a slightly lower degradation rate as compared to different preparations containing only one of the vitamins. Considering that many cosmetic formulations contain vitamin combinations it is suggested that the present study may contribute to the development of more stable formulations containing liposoluble vitamins.Fundacao de Amparo a Pesquisa do Estado de Sao Paulo (FAPESP)Research Pro-Rectory-University of Sao Paul

A HPLC method to evaluate the influence of photostabilizers on cosmetic formulations containing UV-filters and vitamins A and E

This paper reports a simple and reliable HPLC method to evaluate the influence of two currently available photostabilizers on cosmetic formulations containing combined UV-filters and vitamins A and E. Vitamins and UV-filters, widely encountered in products of daily use have to be routinely evaluated since photoinstability can lead to reductions in their efficacy and safety. UV-irradiated formulation samples were submitted to a procedure that included a reliable, precise and specific HPLC method employing a C18 column and detection at 325 and 235 nm. Methanol, isopropanol and water were the mobile phases in gradient elution. The method precision was between 0.28 and 5.07. The photostabilizers studied [diethylhexyl 2,6-naphthalate (DEHN) and benzotriazolyl dodecyl p-cresol (BTDC)], influenced the stability of octyl methoxycinnamate (OMC) associated with vitamins A and E. BTDC was considered the best photostabilizer to vitamins and OMC when the UV-filters were combined with both vitamins A and E. (C) 2010 Elsevier B.V. All rights reserved.Fundacao de Amparo a Pesquisa do Estado de Sao Paulo (FAPESP

Estudo da variação do pH da pele humana exposta à formulação cosmética acrescida ou não das vitaminas A, E ou de ceramida, por metodologia não invasiva

FUNDAMENTOS: Os cosméticos hidratantes melhoram a pele, aproximando-a de suas condições ideais, pois aumentam a quantidade de água no estrato córneo. As vitaminas A e E, bem como as ceramidas, são substâncias ativas que vêm sendo muito empregadas em hidratantes, os quais constituem uma das mais importantes classes de produtos cosméticos e de higiene corporal. OBJETIVO: - O objetivo deste trabalho foi avaliar o efeito no pH cutâneo da pele humana de uma emulsão O/A (constituída de base auto-emulsionante não iônica) acrescida, ou não, de vitamina A palmitato ou vitamina E acetato ou ceramida III, por metodologia não invasiva MÉTODOS:O estudo foi realizado em 40 mulheres com idade entre 30 e 45 anos, empregando-se o equipamento Skin Phmeter PH 900 PC. As medidas foram efetuadas no antebraço das voluntárias nos tempos de sete e 30 dias após auto-aplicação diária (duas vezes ao dia), dos produtos envolvidos no estudo RESULTADOS E CONCLUSÃO: A presença das vitaminas A ou E, ou da ceramida não alterou de maneira significativa o pH da pele, o que mostra que as formulações estudadas são adequadas para o uso cosmético

Evaluation of the photoprotective and antioxidant potential of an avobenzone derivative

Solar radiation can cause damage to the skin, and the use of sunscreens is one of the main protective measures. However, photounstable ultraviolet (UV) filters can generate photoproducts and reactive oxygen species (ROS). Adding antioxidants, such as resveratrol, to enhance the action of UV filters in sunscreens is an interesting strategy for reducing the damage caused by UV radiation exposure. However, new compounds must have their stability, safety and efficacy guaranteed. Avobenzone, a commonly used UV filter, stands out as a promising candidate for structural modification to enhance its stability. Its molecular hybridization with other UV filters and antioxidants can lead to safer and more effective compounds. In this study, the photoprotective and antioxidant potential of a derivative of avobenzone, hybridized with resveratrol’s molecule, was evaluated using in vitro models of cells in monolayer and reconstructed human skin (RHS). Phototoxic potential was assessed using fibroblasts, while the antioxidant activity was measured using the DCFH2-DA probe in HaCaT keratinocytes and in-house RHS. The derivative exhibited UV absorption and demonstrated photostability. It did not exhibit any phototoxic nor photoreactivity potential. Additionally, it was able to photo stabilize a combination of photounstable UV filters, avobenzone and octyl methoxycinnamate, and to reduce their phototoxic potential. In terms of antioxidant activity, the derivative successfully protected against UVA-induced ROS production in the HaCaT keratinocytes model, showing statistical equivalence to the antioxidant control, quercetin (10 μg/mL). Furthermore, experiments conducted in the RHS model demonstrated a significant reduction of 30.7% in ROS generation compared to the irradiated control. This study demonstrated that structural modifications of avobenzone can lead to the development of a broad spectrum (absorbing UVB and UVA II radiation, as well as a portion of the UVA I radiation), non-phototoxic, non-photoreactive and photostable derivative for sunscreen and anti-aging formulations. This derivative enhances protection against oxidative stress induced by UV radiation and improves the effectiveness of sun protection. In addition to the monolayer model, the use of a standardized in-house RHS model was highly relevant for evaluating the effects of UV radiation and skin aging. This model closely mimics human physiological conditions and enables the testing of new compounds and the investigation of protective mechanisms against skin damage

Influence of the Photostabilizer in the Photoprotective Effects of a Formulation Containing UV-Filters and Vitamin A

Vitamin A palmitate has been used in cosmetics; however, studies report that this substance shows photoreactivity that can lead to loss of safety and efficacy. On the other hand, photostabilizers have been used to increase sunscreen photostability and consequently their safety and effectiveness. Thus, this study aimed to evaluate the influence of photostabilizers on the photoprotective effects of a cosmetic formulation containing UV-filters and vitamin A palmitate. The formulation containing UV-filters was supplemented with vitamin A palmitate and the photostabilizers diethylhexyl 2,6-naphthalate (DEHN), bumetrizole and benzotriazolyl dodecyl p-cresol (BTDC). Hairless mice were treated daily by topical applications and irradiated (UVA/B). Erythema index, transepidermal water loss, histological/histometric analysis and number of sunburn cells (SBC) were evaluated. The results showed that all formulations protected from UV-induced enhancement of erythema and SBC but there was no difference among them. The formulation with no stabilizers reduced viable epidermis thickness due to atrophy induced by UV radiation. Thus, it can be concluded that the presence of photostabilizers influenced the effects of formulations containing UV-filters and vitamin A palmitate, which could be seen by histological and histometric analysis. Furthermore, the formulations containing the stabilizers DEHN and BTDC showed better protective effects on hairless mice skin.Fundacao de Amparo a Pesquisa do Estado de Sao Paulo (FAPESP)University of Sao Paulo (USP