No description available.

No description available.

Lingonberries (Vaccinium vitis-idaea) are edible fruit that belong to the Ericaceae plant family. A growing body of evidence suggests that consumption of berries provide considerable health benefits due to their high polyphenols, antioxidants, vitamins and mineral content. Therefore, it is beneficial to evaluate the antioxidant capacity of berries in order to select lines with higher antioxidant capacity. The aim of this study was to determine the antioxidant capacity, total phenolics, total anthocyanins, anti-apoptotic effect and the metabolomic profile of lingonberries from Northern Manitoba (wild) and Newfoundland (greenhouse-grown). A total of 159 lingonberry samples were collected from Northern Manitoba (Lynn Lake and Flin Flon) and Newfoundland. Samples were freeze dried, lyophilized, ground into powder and extracted with solvent methanol. Total anthocyanins were determined by the pH differential method. Total phenolics were evaluated by the Folin-Ciocalteau’s assay, the anti-apoptotic effect was measured fluorescently and the oxygen radical absorbance capacity (ORAC) assay was utilized to evaluate the antioxidant capacity. Our study showed that Northern Manitoba-grown lingonberries contain a higher level of anthocyanins and phenolics compared to Newfoundland greenhouse-grown lingonberries. Results show that Northern Manitoba- grown lingonberries have higher antioxidant capacity compared to ones grown in Newfoundland. Findings from the study suggest that berries grown in green house conditions and extreme climatic conditions have different antioxidant capacity, anti-apoptotic effects, total phenolics and total anthocyanins; that is, more extreme climates may result in berries with higher antioxidant capacity, total phenolics and anthocyanins. / May 2016

The Andean area of South America is the center of origin and diversity of the staple crop potato. Native Andean landraces represent a remarkable gene pool to exploit for the improvement of potato varieties. In the present study, the potential of the native germplasm was evaluated as a source of health-promoting compounds, and more particularly of dietary antioxidants. These phytochemicals receive an increasing interest due to their prospective effects on the prevention of various diseases such as cancers and cardiovascular diseases. In this study, a genetically diverse sample of 74 native potato cultivars (Solanum tuberosum L.) was field grown in 2004 in Huancayo (Peru, 3280 m above sea level). Using screening methods, we found a large variability of total phenolic, total carotenoid, and total vitamin C contents among the potato germplasm. The hydrophilic antioxidant capacity was also measured and was highly correlated with the total phenolics. On the basis of their contrasting contents, 23 potato cultivars were further selected for an in-depth analysis of their carotenoid, polyphenol, and tocopherol profiles. A wide range of antioxidant patterns could also be highlighted as well as cultivars of particular interest from a nutritional point of view. The stability of the ranking of cultivars across environment in terms of phenolic and carotenoid content was subsequently confirmed using 13 contrasted cultivars cultivated in 2005 in another highland environment (Huancani, Peru). This finding supports the fact that the potato genotype is the most determining factor of the observed variability. The effects of a drought stress on the dietary antioxidant contents were then investigated using a selection of five high antioxidant-contrasting cultivars. Drought-induced variations were complex with levels of antioxidants showing increase, decrease or remaining stable, depending on the genotype and the type of antioxidant considered. A gene expression analysis was finally used to gain an insight into the regulation of the production of the polyphenols. We demonstrated that the expression of 8 out of 13 polyphenol-related genes were coordinated and correlated with the polyphenol levels (both constitutive and drought-induced), supporting the fact that the production of polyphenols is, at least in part, controlled at the transcriptional level. Taken together, these results provide useful information concerning the health-promoting potential of the staple crop potato, and particularly of the native germplasm. We demonstrated the high diversity in potato tubers in terms of dietary antioxidants, identified genotypes with nutritionally interesting antioxidant composition, and highlighted their behavior under different environmental and drought stress conditions.

Abstract Recent decades have experienced a sharp increase in the incidence and prevalence of diabetes mellitus. One antidiabetic therapeutic approach is to reduce gastrointestinal glucose production and absorption through the inhibition of carbohydrate-digesting enzymes such as α- amylase and α-glucosidase and α-amylase. The aim of the current study was to screen six medicinal plant species, with alleged antidiabetic properties for α-glucosidase inhibitory activities. Powdered plant materials were extracted with acetone, and tested for ability to inhibit baker's yeast α-glucosidase and α-amylase activities. The largest mass (440 mg from 10 g) of the extract was obtained from Cassia abbreviata, while both Senna italica and Mormordica balsamina yielded the lowest mass of the extracts. Extracts of stem bark of C. abbreviata inhibited baker's yeast α-glucosidase activity with an IC50 of 0.6 mg/ml. This plant species had activity at low concentrations, with 1.0 mg/ml and above resulting in inhibition of over 70%. The other five plant extracts investigated had IC50 values of between 1.8 and 3.0 mg/ml. Senna italica only managed to inhibit the activity of enzyme-glucosidase at high concentrations with an IC50 value of 1.8 mg/ml, while Tinospora fragosa extracts resulted in about 55% inhibition of the activity of the enzyme at a concentration of 3.5 mg/ml, with an estimated IC50 value of 2.8 mg/ml. The bark extract of C. abbreviata was the most active inhibitor of the enzyme, based on the IC50 values (0.6 mg/ml). The bark extract of C. abbreviata contains non-competitive inhibitor(s) of α-glucosidase, reducing Vmax value of this enzyme from 5 mM·s–1 to 1.67 mM·s–1, while Km remained unchanged at 1.43 mMfor para-nitrophenyl glucopyranoside. Antioxidant activity of the extracts was also investigated. The C. abbreviata extract was more active as an antioxidant than the positive control, trolox. The extracts did not inhibit alphaamylase activity more than about 20% at the highest concentration tested.

Abstract Lippia javanica and Lippia scaberrima are used as herbal remedies and are commercially traded as health teas in southern Africa under the brands “Mosukujane” and “Musukudu”, respectively. This study evaluates the relationship between the presence of phenolic compounds and the antioxidant activities of infusions prepared from four Lippia species (L. javanica, L. scaberrima, L. rehmannii and L. wilmsii) indigenous to South Africa. The antioxidant activities of the infusions, determined by the 2,2-diphenylpycrylhydrazyl (DPPH) method, were also compared to those of popular black, green and herbal tea brands. Of the four indigenous species, infusions of L. javanica and L. wilmsii exhibited the highest antioxidant activities (EC50: 358 and 525 μg/ml, respectively) and contained the most phenolic compounds (14.8 and 14.5 mg/ml of dry weight gallic acid equivalent, respectively). Antibacterial activities of methanolic extracts of the four Lippia species were determined against four human pathogens (Staphylococcus aureus, Enterococcus faecalis, Escherichia coli and Pseudomonas aeruginosa). The extract of L. javanica was the most active against all the pathogens tested. Those Lippia species (L. javanica and L. wilmsii) previously reported to produce higher levels of the pharmacologically active phenylethanoid glycosides verbascoside and isoverbascoside, portrayed stronger antioxidant and antibacterial activities. This study gives credence to the use of infusions of these Lippia species for their general health benefits.

Understanding the binding specificity of transcription factors is an important step towards accurate computational prediction of regulatory sequences governing gene expression. Higher-throughput binding site characterization methods have long been available in the laboratory for the study of protein-DNA interactions in solution or upon a surface. In this thesis a new method is introduced for characterization of inducible regulatory sequences in living cells based on construction and analysis of promoter-reporter gene plasmids. Spiked oligonucleotides are used to generate libraries of regulatory sequences with subtle variations from a known regulatory element. Screening of the library in cell culture for the capacity of the mutated sequences to mediate expression provides a diverse collection of responsive and non-responsive sequences to aid in understanding the sequence requirement for an inducible transcription factor binding site. We apply the methodology to the study of antioxidant responsive elements, the target sites of the Nfe212 transcription factor. These target sequences commonly found in the promoters of detoxification genes modulate gene expression in response to a diverse array of chemicals. The variants serve as a primary screen for future targeted mutational analysis to further characterize context-specific sequence requirement in the ARE and/or interdependence between positions. Moreover, a transcription factor binding profile can be generated from functional ARE variants in the library screen. Such an ARE profile performs as well as standard profiles based on bona fide ARE sequences drawn from the scientific literature.

No description available.

Understanding the binding specificity of transcription factors is an important step towards accurate computational prediction of regulatory sequences governing gene expression. Higher-throughput binding site characterization methods have long been available in the laboratory for the study of protein-DNA interactions in solution or upon a surface. In this thesis a new method is introduced for characterization of inducible regulatory sequences in living cells based on construction and analysis of promoter-reporter gene plasmids. Spiked oligonucleotides are used to generate libraries of regulatory sequences with subtle variations from a known regulatory element. Screening of the library in cell culture for the capacity of the mutated sequences to mediate expression provides a diverse collection of responsive and non-responsive sequences to aid in understanding the sequence requirement for an inducible transcription factor binding site. We apply the methodology to the study of antioxidant responsive elements, the target sites of the Nfe212 transcription factor. These target sequences commonly found in the promoters of detoxification genes modulate gene expression in response to a diverse array of chemicals. The variants serve as a primary screen for future targeted mutational analysis to further characterize context-specific sequence requirement in the ARE and/or interdependence between positions. Moreover, a transcription factor binding profile can be generated from functional ARE variants in the library screen. Such an ARE profile performs as well as standard profiles based on bona fide ARE sequences drawn from the scientific literature.

Resumo: O licopeno é um carotenóide com poderosa ação antioxidante, encontrado em maior quantidade no tomate, utilizado no combate a inúmeras doenças como vários tipos de câncer, dentre eles o de próstata, e doenças cardiovasculares. Sua ação tópica é pouco explorada e, por isso, a proposta de ser utilizado no combate à aceleração do envelhecimento cutâneo, incorporado em uma emulsão. Um estudo preliminar foi realizado para a escolha do tipo de tomate que apresenta maior concentração de licopeno e/ou maior atividade antioxidante. O método de quantificação do fitoquímico foi validado e, em função dos testes de avaliação antioxidante in vitro, o tomate do tipo salada foi o escolhido para o desenvolvimento do fitocosmético. Além disso, o extrato foi submetido à avaliação da citotoxicidade in vitro que constatou a não ocorrência de toxicidade em fibroblastos e macrófagos. Assim, o cosmético foi desenvolvido contendo fase oleosa constituída de derivados de karité e submetido a testes para avaliar sua estabilidade, identificar as características da emulsão, avaliar seu comportamento reológico e sua atividade cosmética pelos testes de permeação cutânea e verificando a eficácia quanto à ação antioxidante do licopeno incorporado na emulsão. Foi possível observar que o fitocosmético é estável, de acordo com as condições experimentais realizadas neste estudo, permite a retenção do licopeno na epiderme e na derme e apresenta atividade antioxidante, sendo promissor para o combate à aceleração do envelhecimento cutâneo. / Abstract: Lycopene, a carotenoid with high antioxidant activity, is found in greater quantities in tomatoes used to combat many diseases such as various types of cancers, including of the prostate, and cardiovascular diseases. Its topical action is not explored and therefore the proposal to be used to combat aging, incorporated into an emulsion. A preliminary study was conducted to evaluate which tomato had higher concentration of lycopene and/or higher antioxidant activity. The method of quantification of the phytochemical was validated and the lycopene extract was evaluated by testing in vitro antioxidant activity. Tomato salad was chosen for the development of the phytocosmetic. Furthermore, this extract was subjected to the evaluation of cytotoxicity in vitro activity and it was found that the non-occurrence of toxicity in fibroblasts and macrophages. Thus was developed a product containing oily phase consists only derived about shea which was submitted to tests to assess its stability, to identify the characteristics of the emulsion, to evaluate the rheological behavior and cosmetic activity carried out tests such as skin permeation and checking the effectiveness in the antioxidant action of lycopene incorporated into emulsion. Through the results it was possible to observe that the phytocosmetic is stable, allows the retention of lycopene in the epidermis and dermis, shows antioxidant activity and it's promising to combat the acceleration of skin aging / Orientador: Vera Lucia Borges Isaac / Coorientador: Hérida Regina Nunes Salgado / Banca: Marcos Antônio Correa / Banca: Pedro Alves da Rocha Filho / Mestre