Publications by authors named "Lorena Rigo Gaspar"

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.

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Interest in Antarctic fungi has grown due to their resilience in harsh environments, suggesting the presence of valuable compounds from its organisms, such as those presenting photoprotective potential, since this environment suffers the most dangerous UV exposure in the world. Therefore, this research aimed to assess the photoprotective potential of compounds from sustainable marine sources, specifically seaweed-derived fungi from Antarctic continent. These studies led to discovery of photoprotective and antioxidant properties of metabolites from Arthrinium sp.

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The ocular irritation potential of products that may come into contact with the eyes should be assessed by the combination of different in vitro alternative methods to determine different mechanisms of toxicity previously evaluated by the Draize in vivo assay. Thus, this study proposed to apply two strategies for the prediction of the eye irritation potential of different concentrations of surfactants and silicones, the first one involving evaluation Hen's Egg Test - Chorioallantoic Membrane (HET-CAM), and the other one using Bovine Corneal Opacity and Permeability (BCOP) followed by histopathological. HET-CAM was considered important in assessing the ocular irritation potential and, despite classifying almost all surfactants as "severe irritants", it could discriminate moderate and slight irritant SLES concentrations as well as Cocoamidopropyl Betaine as a severe irritant, when the coagulation score was taken into consideration.

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Objective: To evaluate the safety and the synergistic effects of tea tree, lavender, eucalyptus and tangerine essential oils in combination on the skin using in vitro, ex vivo and clinical studies.

Methods: The phototoxicity was predicted using 3T3 neutral red uptake phototoxicity test (OECD TG 432). Skin penetration was evaluated by confocal Raman microspectroscopy using direct application of essential oils to pig ears.

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Marine-derived fungi proved to be a rich source of biologically active compounds. The genus Penicillium has been extensively studied regarding their secondary metabolites and biological applications. However, the photoprotective effects of these metabolites remain underexplored.

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A challenge for cosmetic and dermatologic products is to develop new high-performance and safer anti-aging products based on new compounds to enhance the stability of retinyl palmitate combined with broad-spectrum UV-filters. Consequently, the aim of this work was to evaluate the effects of three often used avobenzone photostabilizers-ethylhexyl methoxycrylene (EHMCR), tris(tetramethylhydroxypiperidinol) citrate (TTMHP) and tris-biphenyl triazine (TBPT)-on the photostability and phototoxicity of the combination of avobenzone (AVO), octyl methoxycinnamate (OMC) and retinyl palmitate (RP). The photostability studies were performed by the exposure of formulations to UVA radiation.

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Fucoxanthin possesses a well-described antioxidant activity that might be useful for human skin photoprotection. However, there is a lack of scientific information regarding its properties when applied onto human skin. Thus, the objective of the present study was to assess the photoprotective and phototoxicity potential of fucoxanthin based on its ultraviolet (UVB 280-320 nm; UVA 320-400 nm) and visible (VIS 400-700 nm) absorption, photostability, phototoxicity in 3T3 mouse fibroblast culture vs.

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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.

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Visible light can induce the generation of singlet oxygen and can cause oxidative stress, especially in melanocytes due to melanin photosensitization. Currently, there is no organic UV-filter that provide visible light protection. Previous studies showed that some antioxidants, such as apigenin (API), chrysin (CRI) and beta-carotene (BTC) besides neutralizing radical chain reactions can also quench singlet oxygen via physical or chemical quenching and exhibit potential for use in photoprotection.

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Natural products, or secondary metabolites, obtained from fungal species associated with marine algae have been widely used in sunscreens due to their antioxidant activity and protective potential against solar radiation. The endophytic fungus isolated from Bostrychia radicans algae collected in the Rio Escuro mangrove, São Paulo State, Brazil, Annulohypoxylon stygium (Xylariaceae family) was studied to evaluate the photoprotective potential of its metabolites. The Annulohypoxylon genus can produce secondary metabolites with interesting cytotoxic, antibacterial and antioxidant properties and was never isolated before from a marine alga or had its metabolites studied for UV protection.

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Benzophenone-3 (BP-3) is a UV filter with absorption at the UVB and UVA wavelengths which has not been extensively studied in experiments involving its absorbing effects and toxicity. We synthetized four BP-3 derivatives and characterized their photoprotective potential by UV absorption and photodegradation, their phototoxicity potential by 3T3 Neutral Red Uptake (3T3 NRU PT) and their photoreactivity by the reactive oxygen species (ROS) assay. The UV absorption, photodegradation, phototoxicity and photoreactivity of the four BP-3 derivatives (BP-3 carbonate, BP-3 carbazole, BP-3 phenylamine and BP-3 methoxy-phenylamine) were evaluated and compared to those of BP-3.

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The aim of the present study was to investigate the photochemical behavior of DHHB and its photostabilizing effect on avobenzone (AVO) in different sunscreen formulations. The formulations were subjected to photostability studies by HPLC and spectrophotometry. In vitro phototoxicity was assessed using 3T3 fibroblast cultures.

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Currently most of sunscreens provide effective protection in the full UV range but lack VIS protection. The addition of effective antioxidants to sunscreens might afford suitable UV-VIS protection. Apigenin (API), chrysin (CRI) and beta-carotene (BTC) have shown potential for UV-VIS protection.

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Efficient UV-absorbing molecules are designed to protect against UV-light exposure. However, the development of photostable sunscreens is important to preserve the photoprotective efficacy and to prevent the formation of reactive oxygen species (ROS) and photodegradation products, which can promote phototoxic or photoallergic contact dermatitis. The aim of this study was to evaluate the effects of mangiferin and naringenin on the photostability and phototoxicity of sunscreens containing avobenzone.

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Trans-resveratrol (RES) is used in cosmetic formulations and beta-carotene (BTC) is a classical sunscreen antioxidant, but their photostability in sunscreens, a property directly correlated to performance and safety has not been addressed in the literature. This paper reports the assessment of RES and/or BTC influence on the photostability of five UV-filters (octyl methoxycinnamate - OMC, avobenzone -AVO, octocrylene - OCT, bemotrizinole - BMZ, octyltriazone - OTZ) in three different combinations after UVA exposure followed by the identification of degradation products and the assessment of photoreactivity. The evaluation of sunscreen photostability was performed by HPLC and spectrophotometric analysis, and degradation products were identified by GC-MS analysis.

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Retinoids and hydroxy acids have been widely used due to their effects in the regulation of growth and in the differentiation of epithelial cells. However, besides their similar indication, they have different mechanisms of action and thus they may have different effects on the skin; in addition, since the topical formulation efficiency depends on vehicle characteristics, the ingredients of the formulation could alter their effects. Thus the objective of this study was to compare the effects of retinoic acid (RA) and glycolic acid (GA) treatment on the hairless mouse epidermis thickness and horny layer renewal when added in gel, gel cream, or cream formulations.

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This study aimed to assess the phototoxic potential of combined UV-filters and retinyl palmitate (RP) in the presence or not of bemotrizinol (BMTZ), employing photostability and in vitro and in vivo phototoxicity assays. The formulations tested contained octocrylene (OCT), octyl methoxycinnamate (OMC), benzophenone-3 (BZP-3) and RP (photostable) or octocrylene (OCT), octyl methoxycinnamate (OMC), avobenzone (AVO) and RP (less photostable). Both formulations were supplemented with bemotrizinol.

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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.

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The present study aimed to evaluate the photoprotective effects of cosmetic formulations containing a dispersion of liposome with magnesium ascorbyl phosphate (MAP), alpha-lipoic acid (ALA) and kinetin, as well as their effects on the hydration and viscoelastic skin properties. The photoprotection was determined in vitro (antioxidant activity) and in vivo on UV-irradiated hairless mouse skin. The hydration effects were performed with the application of the formulations under study on the forearm of human volunteers and skin conditions were analyzed before and after a single application and daily applications during 4 weeks in terms of transepidermal water loss (TEWL), skin moisture and viscoelastic properties.

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The beneficial photoprotective effects of topical formulations containing combined extracts of Ginkgo biloba (GB) and green tea (GT) have not been investigated. The present study aims to assess the photoprotective effects of topical formulations containing GB and GT combined or not by applications on the dorsal skin of hairless mice prior to UVA/B irradiation. After 20 h, skin barrier damage (TEWL), erythema, histological alterations and sunburn cell formation were evaluated.

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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.

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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.

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Background/purpose: The polysaccharide-rich composition of Aloe vera extracts (Aloe barbadensis Miller), often used in cosmetic formulations, may impart moisturizing properties to the product. The aim of this study was to evaluate the effect of cosmetic formulations containing different concentrations of freeze-dried Aloe vera extract on skin hydration, after a single and a 1- and 2-week period of application, by using skin bioengineering techniques.

Methods: Stable formulations containing 5% (w/w) of a trilaureth-4 phosphate-based blend were supplemented with 0.

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Moisturizers containing vitamins A and E as well as ceramides are believed to improve the skin condition by increasing the water content of the stratum corneum. The aim of this research was to evaluate, through the capacitance method (a non-invasive method), the moisturizing effect of an O/W emulsion (non-ionic self-emulsifying base) containing vitamin A palmitate, vitamin E acetate, and ceramide III on human skin. The studies were carried out on a group of 40 healthy Caucasian female test subjects between 30 and 45 years of age, using the Corneometer CM 825 PC.

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