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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Desenvolvimento e avaliação de nanoemulsões à base de óleo de babaçu (Orbignya oleifera) e extratos vegetais (Areca catechu, Glycyrrhiza glabra e Portulaca oleracea) para uso pós-sol / Development and evaluation of nanoemulsions containing babassu oil (Orbignya oleifera) and vegetable extracts (Areca catechu, Glycyrrhiza glabra e Portulaca oleracea) for after sun use

Gumiero, Viviane Cristina 29 November 2011 (has links)
A nanotecnologia é aplicada em praticamente todos os setores da ciência, incluindo a área cosmética. Nanoemulsões apresentam-se mais estáveis do que macroemulsões, possuem boa espalhabilidade e facilitam a penetração de ativos na pele. O óleo de babaçu (Orbignya oleifera) é utilizado no tratamento de várias afecções da pele, devido às propriedades anti-inflamatória, cicatrizante e antiséptica. O extrato de sementes de Areca catechu inibe a produção de elastase e colagenase, enzimas responsáveis pela flacidez e perda de elasticidade da pele no envelhecimento. Além disso, possui ação antioxidante, anti-hialuronidase, estimulante da proliferação de fibroblastos e inibidor da melanogênese. Outro extrato muito utilizado em cosméticos é o de raízes de Glycyrrhiza glabra que possui atividade antioxidante, anti-inflamatória, adstringente, bactericida e inibidor da tirosinase. Já o extrato de portulaca (Portulaca oleracea), possui propriedades anti-alérgica, anti-inflamatória, anti-irritante e cicatrizante. Nesta pesquisa, desenvolveu-se nanoemulsões contendo óleo de babaçu adicionadas ou não de extratos vegetais e avaliou-se a estabilidade físico-química e propriedades biológicas das mesmas, como potencial antioxidante, anti-irritante, anti-inflamatório, influência na hidratação, valor de pH e oleosidade cutânea. A ordem de adição dos componentes, temperatura, velocidade e tempo de agitação foram críticos na obtenção das nanoemulsões. No estudo de estabilidade acelerada, a 45°C, observou-se alteração significativa dos valores de diâmetro dos glóbulos, pH e condutividade elétrica no final de 120 dias, além da ocorrência simultânea dos processos de Ostwald ripening e coalescência nas duas nanoemulsões. Os extratos de areca, alcaçuz e a formulação aditivada apresentaram atividade antioxidante pelos métodos DPPH e xantina oxidase. Nos testes in vitro de irritação, as formulações foram classificadas como ligeiramente irritantes e não-irritantes pelos métodos HET-CAM e RBC, respectivamente. Por meio dos testes in vivo, observou-se que ambas as formulações apresentaram atividade anti-inflamatória, hidratante, aumento da oleosidade e nenhuma alteração no valor de pH cutâneo. Os resultados obtidos sugerem a segurança e eficácia do uso destas nanoemulsões após exposição solar. / Nanotechnology is applied in all science fields, including the cosmetic. Nanoemulsions are more stable than macroemulsions, have good spreadability and facilitate the active skin penetration. Babassu oil (Orbignya oleifera) is used to treat various skin disorders due to anti-inflammatory, healing and antiseptic properties. Areca catechu seed extract inhibits the collagenase and elastase production, enzymes responsible for sagging and loss of skin elasticity in aging. It also has antioxidant, anti-hyaluronidase, and melanogenesis inhibitor properties. Another extract often used in cosmetics is the Glycyrrhiza glabra roots extract. It has antioxidant, anti-inflammatory, adstringent, antibacterial and tyrosinase inhibitor activities. Yet the portulaca (Portulaca oleracea) extract is anti-allergic, anti-inflammatory, anti-irritant and healing. In this research, babassu nanoemulsions with or without extracts were developed and evaluated for physicochemical stability and biological properties as antioxidant, anti-irritant, anti-inflammatory, hydration, pH value and oily skin. The components addition order, temperature, stirring and time speed were critical in obtaining the nanoemulsions. In accelerated stability tests at 45°C, there was significant change in the droplets size, pH and electrical conductivity values at the end of 120 days. In addition, the Ostwald ripening and coalescence processes occurred simultaneous in nanoemulsions. The areca, licorice and the formulation containing this extracts showed antioxidant activity by DPPH and xanthine oxidase methods. In vitro tests of irritation, the formulations were classified as slightly irritating and non-irritating by HET-CAM and RBC methods, respectively. Both nanoemulsions showed anti-inflammatory, moisturizing characteristic, increased oiliness and none changing in the pH skin value. The results obtained suggest the safety and efficacy of these nanoemulsions after sun exposure.
2

Desenvolvimento e avaliação de nanoemulsões à base de óleo de babaçu (Orbignya oleifera) e extratos vegetais (Areca catechu, Glycyrrhiza glabra e Portulaca oleracea) para uso pós-sol / Development and evaluation of nanoemulsions containing babassu oil (Orbignya oleifera) and vegetable extracts (Areca catechu, Glycyrrhiza glabra e Portulaca oleracea) for after sun use

Viviane Cristina Gumiero 29 November 2011 (has links)
A nanotecnologia é aplicada em praticamente todos os setores da ciência, incluindo a área cosmética. Nanoemulsões apresentam-se mais estáveis do que macroemulsões, possuem boa espalhabilidade e facilitam a penetração de ativos na pele. O óleo de babaçu (Orbignya oleifera) é utilizado no tratamento de várias afecções da pele, devido às propriedades anti-inflamatória, cicatrizante e antiséptica. O extrato de sementes de Areca catechu inibe a produção de elastase e colagenase, enzimas responsáveis pela flacidez e perda de elasticidade da pele no envelhecimento. Além disso, possui ação antioxidante, anti-hialuronidase, estimulante da proliferação de fibroblastos e inibidor da melanogênese. Outro extrato muito utilizado em cosméticos é o de raízes de Glycyrrhiza glabra que possui atividade antioxidante, anti-inflamatória, adstringente, bactericida e inibidor da tirosinase. Já o extrato de portulaca (Portulaca oleracea), possui propriedades anti-alérgica, anti-inflamatória, anti-irritante e cicatrizante. Nesta pesquisa, desenvolveu-se nanoemulsões contendo óleo de babaçu adicionadas ou não de extratos vegetais e avaliou-se a estabilidade físico-química e propriedades biológicas das mesmas, como potencial antioxidante, anti-irritante, anti-inflamatório, influência na hidratação, valor de pH e oleosidade cutânea. A ordem de adição dos componentes, temperatura, velocidade e tempo de agitação foram críticos na obtenção das nanoemulsões. No estudo de estabilidade acelerada, a 45°C, observou-se alteração significativa dos valores de diâmetro dos glóbulos, pH e condutividade elétrica no final de 120 dias, além da ocorrência simultânea dos processos de Ostwald ripening e coalescência nas duas nanoemulsões. Os extratos de areca, alcaçuz e a formulação aditivada apresentaram atividade antioxidante pelos métodos DPPH e xantina oxidase. Nos testes in vitro de irritação, as formulações foram classificadas como ligeiramente irritantes e não-irritantes pelos métodos HET-CAM e RBC, respectivamente. Por meio dos testes in vivo, observou-se que ambas as formulações apresentaram atividade anti-inflamatória, hidratante, aumento da oleosidade e nenhuma alteração no valor de pH cutâneo. Os resultados obtidos sugerem a segurança e eficácia do uso destas nanoemulsões após exposição solar. / Nanotechnology is applied in all science fields, including the cosmetic. Nanoemulsions are more stable than macroemulsions, have good spreadability and facilitate the active skin penetration. Babassu oil (Orbignya oleifera) is used to treat various skin disorders due to anti-inflammatory, healing and antiseptic properties. Areca catechu seed extract inhibits the collagenase and elastase production, enzymes responsible for sagging and loss of skin elasticity in aging. It also has antioxidant, anti-hyaluronidase, and melanogenesis inhibitor properties. Another extract often used in cosmetics is the Glycyrrhiza glabra roots extract. It has antioxidant, anti-inflammatory, adstringent, antibacterial and tyrosinase inhibitor activities. Yet the portulaca (Portulaca oleracea) extract is anti-allergic, anti-inflammatory, anti-irritant and healing. In this research, babassu nanoemulsions with or without extracts were developed and evaluated for physicochemical stability and biological properties as antioxidant, anti-irritant, anti-inflammatory, hydration, pH value and oily skin. The components addition order, temperature, stirring and time speed were critical in obtaining the nanoemulsions. In accelerated stability tests at 45°C, there was significant change in the droplets size, pH and electrical conductivity values at the end of 120 days. In addition, the Ostwald ripening and coalescence processes occurred simultaneous in nanoemulsions. The areca, licorice and the formulation containing this extracts showed antioxidant activity by DPPH and xanthine oxidase methods. In vitro tests of irritation, the formulations were classified as slightly irritating and non-irritating by HET-CAM and RBC methods, respectively. Both nanoemulsions showed anti-inflammatory, moisturizing characteristic, increased oiliness and none changing in the pH skin value. The results obtained suggest the safety and efficacy of these nanoemulsions after sun exposure.
3

An investigation of compounds isolated from Glycyrrhiza Glabra (Liquorice root)

Raubenheimer, Carike 10 1900 (has links)
Introduction: Dark spots appearing on the skin caused by hyperpigmentation results from the action of tyrosinase, an enzyme whose activity leads to the production of the skin pigment melanin. Extracts of the plant Glycyrrhiza glabra, also known as liquorice, are commonly used to treat a range of conditions including skin hyperpigmentation. This study aimed at isolating and identifying compounds in extracts from South African liquorice root and assaying these compounds as to their antioxidant activity, their ability to inhibit the tyrosinase enzyme and their level of cytotoxicity. Methods: The ability of plant extracts to scavenge free radicals was tested using the 2,2-diphenyl-1-picrylhydrazyl (DPPH), [2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonicacid)] (ABTS) and the ferric ion reducing power (FRAP) tests. The polyphenolic content of extract fractions was determined and extract compounds were identified using UHPLC-QToF-20 MS. In vitro anti-tyrosinase activity was also investigated as well as cytotoxicity in HepG2 liver and SK-MEL-1 melanoma cells using the MTT cell viability assay. Results: Of the four fractions prepared from the 70% methanolic extract of liquorice root, fraction 3 (F3) showed increased polyphenolic content and antioxidant properties with IC50 of 56.1 ± 6.32, 39.14 ± 1.1 and 66.34 ± 1.4 μg/ml against DPPH, ABTS and FRAP, respectively. The anti-tyrosinase activity of this fraction showed an IC50 of 358.54 μg/ml compared to Kojic acid (0.75 mM) used as the control. In addition, this fraction showed reduced liver toxicity as a higher percentage cell viability was noted in the HepG2 cells compared to the SK-MEL-1 skin melanoma cells. However, both cell types showed higher percentage viability compared to acetaminophen that was used as cytotoxic control. The LC-MS analysis revealed the presence of a wide variety of compounds including 4-azido-3-benzyl-coumarin, ferulic acid, glycyrrhizin, quercitrin, cirsilineol, gentioflavine and 4'',6,7-trihydroxyisoflavone. The literature indicates the use of these compounds regarding antioxidant and anti-tyrosinase activity. Significantly, cularidine was identified in this study, a compound not previously reported in studies involving liquorice root. Conclusion: The results from this study concur with previous reports as to the anti-tyrosinase and antioxidant activities associated with liquorice roots, activities perhaps due to the relatively high polyphenolic content in extracts from South African liquorice root. / Life and Consumer Sciences / M. Sc. (Life Sciences)

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