Inflammation is a major contributor to postmenopausal bone loss. Various long chain polyunsaturated fatty acids (LCPUFAs), particularly those of the n-3 family, are known to have anti-inflammatory activity and may have a role in minimising postmenopausal bone loss. The objectives of this thesis were to determine whether some LCPUFAs have greater bone-protective effects than others; to identify some of the mechanisms of action of LCPUFAs in bone and to explore the possibility that combined treatment with LCPUFAs and phytoestrogens offers greater bone-protective effects than either treatment alone. Using the ovariectomised rat model for postmenopausal bone loss, the relative effectiveness of eicosapentaenoic acid (EPA, 20:5n-3), docosahexaenoic acid (DHA, 22:6n-3) and gamma-linolenic acid (GLA, 18:3n-6) in minimising bone loss post-ovariectomy was investigated. GLA exacerbated bone loss post ovariectomy in rats. In vitro, treatment of MC3T3-E1/4 osteoblast-like cells with GLA resulted in greater membrane-bound RANKL expression suggesting a possible stimulatory effect of GLA on osteoclastogenesis and osteoclast activity. EPA had no effect on overall bone mass in vivo. DHA significantly ameliorated ovariectomy-induced bone loss possibly by increasing plasma IGF-1 concentration, modulating vitamin D metabolism and, as observed in a second study, by increasing the concentration of gamma-carboxylated osteocalcin. In vitro both EPA and DHA reduced the prostaglandin E2 (PGE2)-induced increase in membrane-bound RANKL expression in MC3T3-E1/4 osteoblast-like cells. However as RANKL-independent pathways are believed to be largely responsible for the ovariectomy-induced increase in osteoclastogenesis in vivo, inhibition of RANKL expression may not significantly contribute to the prevention of ovariectomy-induced bone loss. In a second study in ovariectomised rats, combined treatment with DHA and 17β-oestradiol was associated with significantly higher femur bone mineral content than either treatment alone. However, no beneficial effects of combined treatment with DHA and either of the phytoestrogens genistein or daidzein, on bone mass were apparent. In vitro, co-treatment of TNF-α - exposed MC3T3-E1/4 cells with DHA and 17β-oestradiol was associated with a higher cell number compared to either treatment alone indicating a protective effect of combined treatment against the cytotoxic and/or anti-proliferative effects of TNF-α. In contrast, combined treatment of MC3T3-E1/4 cells with DHA and genistein, but not daidzein, was associated with significantly lower cell number than either treatment alone. As genistein, but not daidzein, is a tyrosine kinase inhibitor, this may indicate that DHA requires tyrosine kinase activity for its protective effect on cell number in TNF-α - exposed osteoblasts. Whether DHA itself is bioactive in bone cells or whether lipid mediators formed from DHA are responsible for the observed bone-protective effects is unknown. Using lipid mediator lipidomic analysis, the presence of DHA-derived lipid mediators in bone marrow in quantities known to be physiologically significant in other tissues was confirmed. Further research into the effects of these lipid mediators in bone and confirmation of the mechanisms of action of DHA in bone cells is required. This thesis demonstrates that consumption of DHA provides some protection against ovariectomy-induced bone loss in vivo and mitigates the effects of inflammation on RANKL signalling and osteoblast cell number in vitro. The bone-protective effects of DHA are complemented by co-treatment with 17β-oestradiol but may be inhibited by co-treatment with the phytoestrogens daidzein or genistein.

This thesis aims to assess the human health impact of exposure to estrogenic compounds from the diet. A multi-disciplinary approach is taken to address various aspects of this issue. An introduction to xenoestrogens, including international research priorities, wildlife and human health effects, mechanisms of action, structure activity relationships and additivity of estrogenic effects is provided as background information. An assessment of exposure to a range of naturally occurring and synthetic estrogenic compounds found in food is derived in Chapter 2. The assessment combines new and existing data on food concentration, food consumption and serum levels for each xenoestrogen. Exposure is combined with relative estrogenic potency data from published bioassasy data to estimate risk relative to normal circulating levels of estradiol. Assuming additivity of xenoestrogens, for an average New Zealand male and for post-menopausal women, xenoestrogens in the diet contribute an additional 12-90% of estrogenicity above normal circulating levels. For a pre-menopausal female, the contribution from the diet represents in the order of an additional 2%. The level of exposure determined in this thesis would seem to be of pharmacological relevance, especially for men with low levels of estrogen and for post-menopausal women. Bisphenol A (BPA) is an important monomer used in the manufacture of epoxy resins for internal food can linings. A survey of the BPA content of a range of 80 canned foods available to the New Zealand consumer was undertaken and the results used in the exposure and risk assessments. BPA was detected in all foods analysed except soft drinks, at concentrations ranging from <10-29 µg/kg, except for individual samples of tuna, corned beef and coconut cream that were 109, 98 and 191 µg/kg respectively. None, of over 4000 individual exposure scenarios, exceeded the temporary Tolerable Daily Intake (TDI) of 10 µg/kg body weight per day set by the Scientific Committee on Food in 2002. Intestinal microflora influence the bioavailability of the naturally occurring xenoestrogens genistein and daidzein that contribute significantly to total estrogenicity from the diet. The degradation of genistein and daidzein by the faecal microfloral of 5 human subjects was variable and unpredictable between individuals and within an individual. These findings have important implications for the promotion and prescription of soy foods and supplements for disease prevention and health benefits. The "yeast assay" is one of a number of methods available to measure estrogenicity. This assay was established and validated. In utero exposure to estrogenic compounds at critical periods of sexual differentiation and endocrine development may imprint for health effects observed later in life. Placental transfer of estrogenicity, from 17β-estradiol was studied using the human placental perfusion model and the yeast assay. The placenta provides a protective barrier to the transfer of estrogenicity. Experiments with genistein showed that 5-15% placental transfer occurred, suggesting that in utero exposure might be in the order of 10% of maternal exposure. The thesis concludes with consideration of a genomic approach to substantiate, or refute, the mechanistic link between exposure to xenoestrogens and claimed human health effect. Such an approach offers exciting opportunity to clarify the mode of action of the synthetic versus the naturally occurring xenoestrogens, to confirm or dispute additivity of effect that is an important premise of the exposure assessment, to identify key genes involved in the many possible health effects and thence risk to the individual from dietary exposure to xenoestrogens.

A genisteína é uma isoflavona da soja que vem sendo investigada pelo seu potencial antienvelhecimento, baseado nas suas atividades antioxidante, estrogênica e inibidora de proteínas tirosina-quinase. A associação da genisteína com β- ciclodextrina com a formação de um complexo elevou a hidrossolubilidade da isoflavona. A permeabilidade intrínseca da genisteína foi avaliada, bem como sua permeabilidade quando aplicada a partir de gel de hidróxi propilmetilcelulose (HPMC) a 3 %, pelo método de célula de Franz. As associações com β-ciclodextrina, em géis de HPMC 3 %, também foram avaliadas e foi observado um incremento da penetração em favor do complexo produzido em meio aquoso. Devido ao seu alto coeficiente de partição (log P) - 4,36 - a genisteína demonstrou a capacidade de formar reservatórios nas estruturas internas da pele favorecendo sua ação antienvelhecimento na pele. / Genistein is a soy isoflavone that has been investigated for its antiaging potencial, based on antioxidant, estrogenic and proteins tirosin-kinase inhibitor activities. The association of genistein with β-cyclodextrin resulted in a complex formation enhanced the isoflavone hidrosolubity. Genistein instrinsic permeability was evaluated, as well permebility from hydroxypropyl methylcelullose (HPMC) 3 % gel, wtih Franz cell method. The associations with β-cyclodextrin, in HPMC 3 % gels were also evaluated with the observation of na enhancing effect of cyclodextrin in the complex produced in aqueous media. Because its high partition coefficient (log P) - 4,36 - genistein was able to form reservoir in the internal skin layers, favorable to its antiagin action.

Estudos recentes têm demonstrado o efeito das isoflavonas da soja, especialmente da genisteína (GEN), administrada topicamente, na prevenção do fotoenvelhecimento e fotocarcinogênesis. Esse efeito tem sido relacionado com a sua atividade inibidora de tirosina quinase e antioxidante. Recentemente, demonstramos um lento perfil de permeação da GEN in vitro (usando células de difusão de Franz) a partir de nanoemulsões através de pele de orelha suína (SILVA et al., Pharmazie, v. 64, p. 32- 35, 2009). Entretanto, estudos relativos à distribuição da GEN através das camadas da pele ainda não foram realizados. Neste contexto, o principal objetivo deste estudo foi avaliar a distribuição da GEN através da pele suína a partir de nanoemulsões, antes e após incorporação em hidrogéis de ácido acrílico, a fim de ajustar a viscosidade das mesmas para aplicação tópica. Nanoemulsões contendo GEN apresentaram valores de potencial  negativos e baixa viscosidade. Os hidrogéis derivados contendo as nanoemulsões de GEN demonstraram um comportamento não-Newtoniano pseudoplástico. Um método isocrático de cromatografia líquida para determinar a GEN nas camadas da pele de orelha suína foi desenvolvido e validado. O método mostrou ser específico, linear, preciso e exato para a determinação da GEN nas camadas da pele de orelha suína (i.e. stratum corneum, epiderme e derme). Nas condições validadas, o perfil de permeação/retenção da GEN foi claramente influenciado pela natureza do núcleo oleoso empregado. Nanoemulsões constituídas de um núcleo oleoso de triglicerídeos de cadeia média apresentaram uma permeação mais lenta e uma maior retenção da GEN na pele quando comparado com nanoemulsões contendo octildodecanol. A incorporação das nanoemulsões de GEN em hidrogéis aumenta a retenção da GEN, especialmente na epiderme. Tal resultado pode estar relacionado com o aumento da hidratação da epiderme como sugerido nas observações histológicas. Em conclusão, o conjunto dos resultados demonstra o efeito das formulações sobre a distribuição da GEN através das camadas da pele de orelha suína. / Recent studies have shown the effect of soy isoflavones, especially genistein (GEN), topically administrated, in preventing skin photoaging and photocarcinogenesis. This effect has been related to tyrosine kinase inhibition and antioxidant activities. Recently, we have demonstrated a slow permeation profile of GEN in vitro (using Franz type diffusion cells) from nanoemulsions through porcine ear skin (SILVA et al., Pharmazie, v. 64, p. 32-35, 2009). However, studies concerning the distribution of GEN in the skin layers have yet to be performed. In this context, the main purpose of this study was to evaluate the GEN distribution through the porcine skin from topical nanoemulsions, before and after their incorporation into acrylic acid-hydrogels, in order to have their viscosity adjusted to topical applications. Nanoemulsions containing GEN exhibit negative -potential and low viscosity. The derived hydrogels containing GEN-loaded nanoemulsions presents non-Newtonian pseudoplastic behavior. An isocratic liquid chromatographic method to determine GEN in porcine ear skin layers was developed and validated. The method proved to be specific, linear, precise and accurate to determine GEN in the porcine skin layers (i.e. stratum corneum, epidermis and dermis). In the validated conditions, the GEN permeation/ retention profile was clearly influenced by the nature of the oil core used. Nanoemulsions composed by a medium chain triglycerides oil core exhibit both a slower permeation and a higher retention profile of GEN as compared to octyldodecanol nanoemulsions. The incorporation of GEN-loaded nanoemulsion into hydrogels improved the GEN retention, especially in the epidermis. Such a result might be related to the increased hydration of epidermis as suggested in histological observations. In conclusion, the overall results show the effect of the formulation on distribution of GEN through the porcine skin layers.

Estudos recentes têm demonstrado o efeito das isoflavonas da soja, especialmente da genisteína (GEN), administrada topicamente, na prevenção do fotoenvelhecimento e fotocarcinogênesis. Esse efeito tem sido relacionado com a sua atividade inibidora de tirosina quinase e antioxidante. Recentemente, demonstramos um lento perfil de permeação da GEN in vitro (usando células de difusão de Franz) a partir de nanoemulsões através de pele de orelha suína (SILVA et al., Pharmazie, v. 64, p. 32- 35, 2009). Entretanto, estudos relativos à distribuição da GEN através das camadas da pele ainda não foram realizados. Neste contexto, o principal objetivo deste estudo foi avaliar a distribuição da GEN através da pele suína a partir de nanoemulsões, antes e após incorporação em hidrogéis de ácido acrílico, a fim de ajustar a viscosidade das mesmas para aplicação tópica. Nanoemulsões contendo GEN apresentaram valores de potencial  negativos e baixa viscosidade. Os hidrogéis derivados contendo as nanoemulsões de GEN demonstraram um comportamento não-Newtoniano pseudoplástico. Um método isocrático de cromatografia líquida para determinar a GEN nas camadas da pele de orelha suína foi desenvolvido e validado. O método mostrou ser específico, linear, preciso e exato para a determinação da GEN nas camadas da pele de orelha suína (i.e. stratum corneum, epiderme e derme). Nas condições validadas, o perfil de permeação/retenção da GEN foi claramente influenciado pela natureza do núcleo oleoso empregado. Nanoemulsões constituídas de um núcleo oleoso de triglicerídeos de cadeia média apresentaram uma permeação mais lenta e uma maior retenção da GEN na pele quando comparado com nanoemulsões contendo octildodecanol. A incorporação das nanoemulsões de GEN em hidrogéis aumenta a retenção da GEN, especialmente na epiderme. Tal resultado pode estar relacionado com o aumento da hidratação da epiderme como sugerido nas observações histológicas. Em conclusão, o conjunto dos resultados demonstra o efeito das formulações sobre a distribuição da GEN através das camadas da pele de orelha suína. / Recent studies have shown the effect of soy isoflavones, especially genistein (GEN), topically administrated, in preventing skin photoaging and photocarcinogenesis. This effect has been related to tyrosine kinase inhibition and antioxidant activities. Recently, we have demonstrated a slow permeation profile of GEN in vitro (using Franz type diffusion cells) from nanoemulsions through porcine ear skin (SILVA et al., Pharmazie, v. 64, p. 32-35, 2009). However, studies concerning the distribution of GEN in the skin layers have yet to be performed. In this context, the main purpose of this study was to evaluate the GEN distribution through the porcine skin from topical nanoemulsions, before and after their incorporation into acrylic acid-hydrogels, in order to have their viscosity adjusted to topical applications. Nanoemulsions containing GEN exhibit negative -potential and low viscosity. The derived hydrogels containing GEN-loaded nanoemulsions presents non-Newtonian pseudoplastic behavior. An isocratic liquid chromatographic method to determine GEN in porcine ear skin layers was developed and validated. The method proved to be specific, linear, precise and accurate to determine GEN in the porcine skin layers (i.e. stratum corneum, epidermis and dermis). In the validated conditions, the GEN permeation/ retention profile was clearly influenced by the nature of the oil core used. Nanoemulsions composed by a medium chain triglycerides oil core exhibit both a slower permeation and a higher retention profile of GEN as compared to octyldodecanol nanoemulsions. The incorporation of GEN-loaded nanoemulsion into hydrogels improved the GEN retention, especially in the epidermis. Such a result might be related to the increased hydration of epidermis as suggested in histological observations. In conclusion, the overall results show the effect of the formulation on distribution of GEN through the porcine skin layers.

A genisteína é uma isoflavona da soja que vem sendo investigada pelo seu potencial antienvelhecimento, baseado nas suas atividades antioxidante, estrogênica e inibidora de proteínas tirosina-quinase. A associação da genisteína com β- ciclodextrina com a formação de um complexo elevou a hidrossolubilidade da isoflavona. A permeabilidade intrínseca da genisteína foi avaliada, bem como sua permeabilidade quando aplicada a partir de gel de hidróxi propilmetilcelulose (HPMC) a 3 %, pelo método de célula de Franz. As associações com β-ciclodextrina, em géis de HPMC 3 %, também foram avaliadas e foi observado um incremento da penetração em favor do complexo produzido em meio aquoso. Devido ao seu alto coeficiente de partição (log P) - 4,36 - a genisteína demonstrou a capacidade de formar reservatórios nas estruturas internas da pele favorecendo sua ação antienvelhecimento na pele. / Genistein is a soy isoflavone that has been investigated for its antiaging potencial, based on antioxidant, estrogenic and proteins tirosin-kinase inhibitor activities. The association of genistein with β-cyclodextrin resulted in a complex formation enhanced the isoflavone hidrosolubity. Genistein instrinsic permeability was evaluated, as well permebility from hydroxypropyl methylcelullose (HPMC) 3 % gel, wtih Franz cell method. The associations with β-cyclodextrin, in HPMC 3 % gels were also evaluated with the observation of na enhancing effect of cyclodextrin in the complex produced in aqueous media. Because its high partition coefficient (log P) - 4,36 - genistein was able to form reservoir in the internal skin layers, favorable to its antiagin action.

A genisteína é uma isoflavona da soja que vem sendo investigada pelo seu potencial antienvelhecimento, baseado nas suas atividades antioxidante, estrogênica e inibidora de proteínas tirosina-quinase. A associação da genisteína com β- ciclodextrina com a formação de um complexo elevou a hidrossolubilidade da isoflavona. A permeabilidade intrínseca da genisteína foi avaliada, bem como sua permeabilidade quando aplicada a partir de gel de hidróxi propilmetilcelulose (HPMC) a 3 %, pelo método de célula de Franz. As associações com β-ciclodextrina, em géis de HPMC 3 %, também foram avaliadas e foi observado um incremento da penetração em favor do complexo produzido em meio aquoso. Devido ao seu alto coeficiente de partição (log P) - 4,36 - a genisteína demonstrou a capacidade de formar reservatórios nas estruturas internas da pele favorecendo sua ação antienvelhecimento na pele. / Genistein is a soy isoflavone that has been investigated for its antiaging potencial, based on antioxidant, estrogenic and proteins tirosin-kinase inhibitor activities. The association of genistein with β-cyclodextrin resulted in a complex formation enhanced the isoflavone hidrosolubity. Genistein instrinsic permeability was evaluated, as well permebility from hydroxypropyl methylcelullose (HPMC) 3 % gel, wtih Franz cell method. The associations with β-cyclodextrin, in HPMC 3 % gels were also evaluated with the observation of na enhancing effect of cyclodextrin in the complex produced in aqueous media. Because its high partition coefficient (log P) - 4,36 - genistein was able to form reservoir in the internal skin layers, favorable to its antiagin action.

Made available in DSpace on 2014-07-29T15:12:42Z (GMT). No. of bitstreams: 1 Dissertacao Liliane Radoll Ribeiro.pdf: 85648 bytes, checksum: 100baebe5e75ae9143311e745c1f60d3 (MD5) Previous issue date: 2008-04-28 / Genistein is the most abundant isoflavone, displaying the largest number of biological activities. Most studies on genistein have been based on its antioxidant, estrogenic, tyrosine kinase and carcinogenesis inhibitor activities. Genistein is practically insoluble in water and oil in the active form of aglicone, which presents a technical difficulty. To circumvent this problem, the encapsulation of genistein in phosphatidylcholine liposomes seems an efficient alternative for the improvement of solubility. In this work, genistein was encapsulated in phosphatidylcholine liposomes and the drugphospholipid interactions were characterized. It was demonstrated that the interaction of genistein with this lipid membrane model lead to an increased membrane rigidity caused by a tighter packing of the phospholipid bilayer. Encapsulation efficiency for genistein in liposomes reached 99%, with a maximum loading efficiency at the molar ratio of 1:3 (genistein:phosphatidylcholine), resulting in an increase of 1000 times in the water solubility of genistein. Genistein was able to protect membrane phospholipids against CuSO4 induced peroxidation. The liposomal preparation remained stable for at least 40 days, showing its potential as a nanostructured delivery system for this isoflavone for therapeutic and cosmetic applications. / A genisteína é a isoflavona mais abundante e que exibe o maior número de atividades biológicas. A maioria dos estudos sobre a genisteína tem sido realizada com base nas suas atividades antioxidante, estrogênica, inibidora da tirosina quinase e inibidora da carcinogênese. No entanto, a genisteína possui uma dificuldade tecnológica: é pouco solúvel em água e óleo, quando na forma ativa de aglicona. Para contornar esse problema, a encapsulação da genisteína em lipossomas de fosfatidilcolina parece uma alternativa eficaz para a melhora da solubilidade. No presente trabalho, a genisteína foi encapsulada em lipossomas de fosfatidilcolina e as interações entre este fármaco e o fosfolipídeo foram caracterizadas. Foi possível demonstrar que as interações fármaco-lipídeo neste modelo aumentam a rigidez da membrana lipídica devido ao maior empacotamento dos fosfolipídeos na bicamada. A eficiência de encapsulação da genisteína em lipossomas foi elevada, chegando ao índice 99 %, com encapsulação máxima na razão molar de 1:3 (genisteína:fosfolipídeo), o que promove o aumento da solubilidade da genisteína na solução aquosa em cerca de 1000 vezes. Foi demonstrado o efeito protetor antioxidante da genisteína sobre os fosfolipídeos de membrana. A preparação lipossomal permaneceu estável por pelo menos 40 dias, evidenciando seu potencial como sistema carreador para esta isoflavona em aplicações terapêuticas e cosméticas.

According to the American Cancer Society, breast cancer is the most commonly diagnosed cancer and is the second leading cause of cancer death in American women. Breast cancer screenings and improvement in treatments have resulted in the rising number of survivors in the recent decade. This urged the need for post-diagnosis lifestyle changes to improve breast cancer patients' quality of life. Many studies found soy food, the primary dietary source of phytoestrogens, has a protective effect against breast cancer recurrence and mortality. Dietary phytoestrogens can be classified into two groups: isoflavones and lignans. Daidzein and genistein were identified as the most common isoflavones. Due to their structural similarities to 17- beta estradiol, isoflavones exert agonistic and antagonistic effects. However, limited studies have evaluated the effect of phytoestrogen on health-related quality of life (HRQOL) among cancer survivors. This thesis examined the association between genistein levels and HRQOL and whether these associations are altered by menopausal status using data collected by a research team in South Korea. Women aged 21 to 81 years old, diagnosed with stage I – III primary breast cancer, and received breast cancer surgery at least six months prior were enrolled from five hospitals. Plasma genistein level was measured by orbitrap liquid chromatography-mass spectrometry at the University of Hawaii Cancer Center, Honolulu, Hawaii, U.S.A. HRQOL was self-reported using a validated Korean version of the SF-36 questionnaire. SF-36 has eight domain scores. The scores are summarized into physical (PCS) and mental (MCS) component summary scores, with a higher score indicating better HRQOL. The association between plasma genistein and HRQOL was assessed using a multiple linear regression model adjusting for potential confounders. Stratified analysis was conducted to examine whether menopause status modified this association. 407 women (mean age: 52.1 ± 8.3) with all available data were included in the analysis. The mean blood genistein concentration was 144.7 nM (range: 1.1- 2073.0 nM), and the PCS and MCS scores were 49.5 ± 7.1 and 49.2 ± 9.8, respectively. Analysis for the entire sample showed no significant associations between genistein level and HRQOL score across all domains. Further subgroup analysis by menopausal status revealed that only pre- menopausal women in the highest tertile level of genistein had a higher social function domain score (48.9 vs. 47.2) than those in the lowest tertile with a borderline statistical significance (p = 0.083). These findings suggest beneficial effects of genistein may depend on women's menopausal status, but further investigation is necessary.

No description available.