Estudi de la superfície d'absorció a l'intestí prim de pollastre al llarg del desenvolupament

Tesi de Llicenciatura per a la obtenció del Grau de Farmàcia. Facultat de Farmàcia. Universitat de Barcelona. Director: Ruth Ferrer i Roig. 1994

Alternative Methods to Animal Testing for the Safety Evaluation of Cosmetic Ingredients: An Overview

The safety of cosmetics sold in Europe is based on the safety evaluation of each individual ingredient conducted by those responsible for putting the product on the market. However, those substances for which some concern exists with respect to human health (e.g., colorants, preservatives, UV-filters, nanomaterials) are evaluated at the European Commission level by a scientific committee, currently called the Scientific Committee on Consumer Safety (SCCS). According to the Cosmetics Regulation (European Commission, 2009), it is prohibited in the European Union (EU) to market cosmetic products and ingredients that have been tested on animals. However, the results of studies performed before the ban continue to be accepted. In the current study, we evaluated the use of in vitro methods in the dossiers submitted to the SCCS in the period between 2013 and 2016 based on the published reports issued by the scientific committee, which provides a scientific opinion on these dossiers. The results of this evaluation were compared with those of an evaluation conducted four years previously. We found that, despite a slight increase in the number of studies performed in vitro, the majority of studies submitted to the SCCS is still done principally in vivo and correspond to studies performed before the ban

Antitumor activities of metal oxide nanoparticles

Nanoparticles have received much attention recently due to their use in cancer therapy. Studies have shown that different metal oxide nanoparticles induce cytotoxicity in cancer cells, but not in normal cells. In some cases, such anticancer activity has been demonstrated to hold for the nanoparticle alone or in combination with different therapies, such as photocatalytic therapy or some anticancer drugs. Zinc oxide nanoparticles have been shown to have this activity alone or when loaded with an anticancer drug, such as doxorubicin. Other nanoparticles that show cytotoxic effects on cancer cells include cobalt oxide, iron oxide and copper oxide. The antitumor mechanism could work through the generation of reactive oxygen species or apoptosis and necrosis, among other possibilities. Here, we review the most significant antitumor results obtained with different metal oxide nanoparticles

Nanocarriers for Delivery of Antioxidants on the Skin

Skin is protected from the harmful effects of free radicals by the presence of an endogenous antioxidant system. However, when exposed to ultraviolet (UV) radiation, there is an imbalance between pro-oxidants and antioxidants, leading to oxidative stress and photoaging of the skin. It has been described that free radicals and other reactive species can cause severe damage to cells and cell components of the skin, which results in skin aging and cancer. To prevent these actions on skin, the use of topical antioxidant supplementation is a strategy used in the cosmetics industry and these antioxidants act on quenching free radicals. There are many studies that demonstrated the antioxidant activity of many phytochemicals or bioactive compounds by free radical scavenging. However, many bioactive substances are unstable when exposed to light or lose activity during storage. The potential sensitivity of these substances to light exposure is of importance in cosmetic formulations applied to skin because photo-degradation might occur, reducing their activity. One strategy to reduce this effect on the skin is the preparation of different types of nanomaterials that allow the encapsulation of the antioxidant substances. Another problem related to some antioxidants is their inefficient percutaneous penetration, which limits the amount of the active ingredient able to reach the site of action in viable epidermis and dermis. In this sense, the encapsulation in polymeric nanoparticles could enhance the permeation of these substances. Nanocarriers offers several advantages over conventional passive delivery, such as increased surface area, higher solubility, improved stability, controlled release, reduced skin irritancy, and protection from degradation. The different nanocarrier systems used in cosmetics include nanolipid delivery systems such as solid lipid nanoparticles (SLN) and nanostructured lipid carriers (NLC), nanoemulsions (NEs), nanoparticles (NP) suspension, and polymer NPs, among others. In this review, we present the different types of nanomaterials use

Melanogenesis and hypopigmentation: the case of vitiligo

Melanocytes are highly specialized dendritic cells that synthesize and store melanin in subcellular organelles called melanosomes, before transfer to keratinocytes. Melanin is a complex pigment that provides colour and photoprotection to the skin, hair and eyes. The process of synthesis of melanin is called melanogenesis and is regulated by various mechanisms and factors such as genetic, environmental and endocrine factors. The knowledge of the pigmentation process is important to understand hypopigmentation disorders such as vitiligo and also to design adequate treatments. In the present work, we review the signalling pathways involved in vitiligo. Finally, current therapies and treatments including topical, oral and phototherapies are discussed and described, emphasizing future therapies based on different pigmentation mechanisms

Establishment of an In Vitro Photoallergy Test Using NCTC2544 Cells and IL-18 Production

Differentiation between photoallergenic and phototoxic reactions induced by low molecular weight compounds represents a current problem. The use of eratinocytes as a potential tool for the detection of photoallergens as opposed to photoirritants is considered an interesting strategy for developing in vitro methods. We have previously demonstrated the possibility to use the human keratinocyte cell line NCTC2455 and the production of interleukin-18 (IL-18) to screen low molecular weight sensitizers. The purpose of this work was to explore the possibility to use the NCTC2544 assay to identify photoallergens and discriminate from phototoxic chemicals. First, we identified suitable condition of UV-irradiation (3.5 J/cm2) by investigating the effect of UVAirradiation on intracellular IL-18 on untreated or chloropromazine (a representative phototoxic compound)- treated NCTC2544 cells. Then, the effect of UVA-irradiation over NCTC2544 cells treated with increasing concentrations of 15 compounds including photoallergens (benzophenone, 4-ter-butyl-4-methoxydibenzoylmethane, 2-ethylexyl-p-methoxycinnamate, ketoprofen, 6-methylcumarin); photoirritant and photoallergen (4-aminobenzoic acid, chlorpromazine, promethazine); photoirritants (acridine, ibuprofen, 8-methoxypsoralen, retinoic acid); and negative compounds (lactic acid, SDS and p-phenilendiamine) was investigated. Twenty-four hours after exposure, cytotoxicity was evaluated by the MTT assay or LDH leakage, while ELISA was used to measure the production of IL-18. At the maximal concentration assayed with non-cytotoxic effects (CV80 under irradiated condition), all tested photoallergens induced a significant and a dose-dependent increase of intracellular IL-18 following UVA irratiation, whereas photoirritants failed. We suggest that this system may be useful for the in vitro evaluation of the photoallergic potential of chemicals

Innovative Strategies for Photoallergy Assessment: Breaking Free from Animal Models in Cosmetic Ingredient Development

Photoallergy, a unique form of skin sensitization induced by specific compounds underultraviolet irradiation, has traditionally been investigated using animals. However, the prohibition ofanimal testing for the assessment of cosmetic ingredients in Europe and other countries underscoresthe necessity for in vitro or in silico alternative methods. Currently, there are no validated methods forassessing photoallergy or photosensitization, presenting a significant challenge in the development ofnew cosmetic ingredients. This review examines the landscape of alternative methods for detectingphotosensitization, emphasizing recent publications, and considering the underlying principles ofthe different proposed assays.</p

Melanogenesis and Melasma Treatment

Melanocytes are highly specialised dendritic cells that transfer melanin to keratinocytes in subcellular lysosome-like organelles called melanosomes, where melanin is synthesised and stored. Melanin is a complex pigment that provides colour and photoprotection to the skin, hair, and eyes of mammals. The regulation of melanogenesis includes various mechanisms and factors including genetic, environmental, and endocrine factors. Knowledge of the pigmentation process is important not only to understand hyperpigmentation but also to design treatments and therapies to treat them. Whitening cosmetics with anti-melanogenesis activity are very popular. In the present manuscript, we review the mechanisms and the signalling pathways involved in skin pigmentation and we specifically focus on the alteration of melanogenesis that leads to melasma and results in hyperpigmentation. Finally, current therapies and treatments including topical, oral, and phototherapies are discussed and described, with a special emphasis on the cosmetics' action

Actividades de aprendizaje y evaluación a través del Campus Virtual. Experiencia en Fisiología y Fisiopatología I del Grado de Farmacia

[spa] Nuestro objetivo consiste en fomentar, entre alumnos internos del Departamento de Fisiología, el autoaprendizaje, el trabajo autónomo y en equipo, espíritu crítico y habilidad para buscar y analizar información. A la vez se pretende iniciar a estos alumnos en los sistemas de transferencia de resultados de la investigación básica a la investigación aplicada. Para ello a los alumnos se les proporciona materiales que contienen información sobre las materias objeto de aprendizaje y enlaces a diferentes sitios webs de interés relacionados con el tema. En ellos se promueve la exposición de trabajos y la participación en jornadas especializadas. El uso de estos materiales bajo supervisión del profesorado, ha permitido la mejora del conocimiento en Fisiología y la creación de equipos especializados en diferentes aspectos de la Fisiología. Además, la transferencia de información entre alumnos, ha propiciado que puedan adquirir una visión clara y amplia sobre qué es un trabajo de investigación básica o un trabajo de investigación aplicada, así como la importancia del trabajo en equipo, lo que ha posibilitado que pudieran diseñar pequeños experimentos y estudiar su aplicabilidad. Al final del periodo de formación, los alumnos demostraron haber adquirido las competencias genéricas CG1, CG3, CG5, CG6, CG11, CG13 y CG15 incluidas en la ficha Verifica para el Grado en Farmacia, así como las competencias específicas para el módulo 5 (Medicina y Farmacología) CEM5.8, CEM5.9 y CEM5.11, concluyendo así que la aplicación de métodos de enseñanza basados en el autoaprendizaje (bajo supervisión de equipos docentes) constituye una excelente herramienta para la promoción de la adquisición de competencias generales y específicas en el Grado en Farmacia.[eng]Our goal is to motivate students of physiology in the area of independent study, working alone and in groups, enabling them to develop a critical spirit and skills, and to be capable of seeking and analyzing information. At the same time, we seek to introduce these students to the systems of transferring results from basic to applied research. For this purpose, the students were provided with materials containing information on subjects appropriate for independent study, and links to various websites of interest related to the subject. The teaching staff promoted the presentation of students’ projects, and encouraged them to participate in specialized workshops. The use of these materials, under the teachers’ supervision, has led to the students acquiring greater knowledge of physiology, and to the creation of teams specialized in diverse aspects of the subject. Moreover, the transfer of information among students has made it possible for them to acquire a keen, broad-ranging view of what is involved in a basic or applied research project, and to understand the importance of working as part of a team. Thus, the students designed small-scale experiments and studied their applicability. By the end of this training period, the students showed they had acquired the generic skills 1, 3, 5, 6, 11, 13 and 15 required to be awarded a Degree in Pharmacy, as well as the specific skills necessary for Module 5 (Medicine and Pharmacology), numbers 5.8, 5.9 and 5.11. Accordingly, it can be concluded that the application of teaching methods based on independent study (under the supervision of teaching staff) constitutes an excellent tool for promoting students’ acquisition of general and specific skills as part of their studies for the Pharmacy Degree

Evaluation of Anti-Tyrosinase and Antioxidant Properties of Four Fern Species for Potential Cosmetic Applications

Ferns are poorly explored species from a pharmaceutical perspective compared to other terrestrial plants. In this work, the antioxidant and tyrosinase inhibitory activities of hydrophilic and lipophilic extracts, together with total polyphenol content, were evaluated in order to explore the potential cosmetic applications of four Spanish ferns collected in the Prades Mountains (Polypodium vulgare L., Asplenium adiantum-nigrum L., Asplenium trichomanes L., and Ceterach officinarum Willd). The antioxidant activity was evaluated using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical, oxygen radical absorbance capacity (ORAC) and xanthine/xanthine oxidase (X/XO) assays. The potential to avoid skin hyperpigmentation was tested by inhibiting the tyrosinase enzyme, as this causes melanin synthesis in the epidermis. All ferns were confirmed as antioxidant and anti-tyrosinase agents, but interestingly hydrophilic extracts (obtained with methanol) were more potent and effective compared to lipophilic extracts (obtained with hexane). Polypodium vulgare, Asplenium adiantum-nigrum, and Ceterach officinarum methanolic extracts performed the best as antioxidants. Polypodium vulgare methanolic extract also showed the highest activity as a tyrosinas