Two dietary polyphenols, delphinidin and resveratrol, were selected for this study; delphinidin, an anthocyanin flavonoid, was found to elicit cardioprotective properties from a pilot study and resveratrol, a stilbene flavonoid, one of the most studied of the polyphenols and was chosen as a worthy comparator. <i>In vitro</i> studies using cultured endothelial cells exposed to a variety of reactive oxygen species (ROS) were used to determine if delphinidin and resveratrol could protect these cells from oxidative damage. It was found that physiological concentrations of delphinidin protected these cells from hydroxyl-radical damage. However, resveratrol failed to show any protective effects. Oxidative stress was induced in porcine coronary artery using diethyldithiocarbamate (DETCA), an inhibitor of the superoxide dismutase (SOD). Sensitivity to nitric oxide (NO) was preserved in endothelium-denuded vessels that were pre-treated with delphinidin, but not with resveratrol. However, studies where a balloon catheter was used to induce injury to the endothelium, delphinidin pre-treatment did not preserve sensitivity to NO in these vessels. Taken together, these results suggest that delphinidin, but not resveratrol, has potential to protect the endothelium from oxidative stress by preserving/protecting NO bioavailability and by acting directly as an antioxidant or indirectly upregulating antioxidant systems.

Thesis (MTech (Food Technology))--Cape Peninsula University of Technology, 2016. / The Maillard reaction (MR) involves the condensation reaction between amino acids or proteins with reducing sugars, which occurs commonly in food processing and storage. Maillard reaction products (MRPs) were prepared from glucose-casein model system at pH 8, heated at 60, 75 and 90°C for 6, 12 and 24 h, respectively. Browning intensity (BI) of MRPs, as monitored by absorbance at 420 nm increased with an increase in reaction temperature. The reducing power (RP) of MRPs increased (p < 0.05) as the reaction time increased at 60 and 75°C, while at 90°C an increase in RP was observed from 6 to 12 h and thereafter a slight decrease was observed up to 24 h. The 2,2-Azino-bis-(3-ethylbenzthiazoline-6-sulfonic acid) radical scavenging activity (ABTS-RS) and Peroxyl radical scavenging (PRS) activity of glucose-casein MRPs produced at 90°C decreased as the reaction time increased. In this study, the ferrous chelation activity of MRPs was higher than that of tert-butylhydroquinone (TBHQ) (0.02%) and Trolox (1 mM), respectively. Moreover, the 1, 1-diphenyl-2-picryl-hydrazil radical scavenging (DPPH-RS) of MRPs increased (p < 0.05) as the reaction time increased irrespective of the heating temperature. The primary and secondary lipid oxidation products were measured using the Peroxide value (PV) and Thiobarbituric acid reactive substance (TBARs) assay in sunflower oil-in-water emulsion, respectively. MRPs derived at 90°C for 12 h had the lowest peroxide value, while the TBARs inhibitory by MRPs ranged from 39.05 – 88.66%. Glucose-casein MRPs displayed superior antioxidant activity than TBHQ (0.02%) and Trolox (1 mM), respectively, as measured by the TBARs assay. The differential scanning calorimetry (DSC) and Rancimat techniques set at 110°C were used to evaluate the oxidative stability the lipid-rich media containing MRPs. At the same temperature program, DSC gave significantly lower reduction times than the Rancimat. Furosine (N-ε-Fructosyl-lysine) and Pyrraline (2-amino-6-(2-formyl-5-hydroxymethyl-1-pyrrolyl)-hexanoic acid) were determined using high pressure liquid chromatography to evaluate the extent of the MR. Furosine concentration of glucose-casein MRPs ranged between 0.44 – 1.075 mg.L-1 in MRPs derived at 60°C, while at 75°C an increase as function of time was observed. MRPs derived at 60 and 75°C exhibited a varied concentration of pyrraline as the reaction time increased with higher temperatures resulted in higher concentrations (0.39 mg.L-1). The results of this study clearly indicated that MRPs possess antioxidant activity and can be used as natural antioxidants in the food industry.

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Qi Chang. / "March 2002." / Thesis (Ph.D.)--Chinese University of Hong Kong, 2002. / Includes bibliographical references (p. 173-192). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Mode of access: World Wide Web. / Abstracts in English and Chinese.

Orientador: Regildo Márcio Gonçalves da Silva / Co-orientador: André Rolim Baby / Banca: Isabel Cristina Cherici Camargo / Banca: Giuseppina Pace Pereira Lima / Resumo: O desenvolvimento de novos fármacos com ação antioxidante tem sido um importante objeto de estudo, uma vez que a terapêutica farmacológica atual para o tratamento de doenças como Alzheimer, Parkinson, esclerose múltipla, doença de Huntington, epilepsia e alguns tipos de neoplasias pode ser realizada devido às propriedades antioxidantes de muitos compostos naturais e/ou sintéticos. Dessa forma, a busca por novos agentes antioxidantes é extremamente necessária e atualmente é objeto de interesse em novas pesquisas pela indústria cosmética, farmacêutica e nutricional. Neste contexto, este trabalho irá permitir o aumento do conhecimento sobre Moringa oleifera por meio da avaliação do potencial antioxidante, fotoprotetor e antiglicação dos extratos desta espécie, além de elucidar relatos etnobotânicos de sua utilização e enriquecer o conhecimento científico desta espécie amplamente empregada como planta medicinal. Além disso, porque são reduzidas as informações científicas sobre as atividades que serão avaliadas neste projeto / Abstract: The development of new drugs with antioxidant action has been an important subject of study, since the current drug therapy for the treatment of diseases such as Alzheimer's, Parkinson's, multiple sclerosis, Huntington's disease, epilepsy and some types of cancer can be performed because the antioxidant properties of many natural and / or synthetic compounds. Thus, the search for new antioxidants is extremely necessary and is currently the subject of interest in new research by the cosmetic, pharmaceutical and nutritional industry. In this context, this work will enable increased knowledge on Moringa oleifera by evaluating the antioxidant potential, sunscreen and anti-glycation of the extracts of this species, besides elucidating ethnobotanical reports of its use and enrich the scientific knowledge of this widely used species with medicinal plant. In addition they are reduced scientific information on the activities to be evaluated in this project / Mestre

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Dengue fever is an arthropod-borne transmit disease, caused by dengue virus.The principal vectors are Aedes aegypti and Aedes albopictus. Induce Dengue fever (DF) and a more severe form of dengue hemorrhagic fever (DHF), dengue shock syndrome (DSS). Dengue virus is the most prevalent arbovirus in tropical and subtropical regions. There is no specific drug and vaccine available for treatment and prevention. Therefore, DF is an important disease among transmit diseases in humans. For the effective control and prevention of DF transmission, rapid quantitative molecular biological methods are very important for the diagnosis of dengue fever. At present, there are many methods to isolate the RNA of Dengue virus; however, the new developed magnetic method has not been used for the Dengue virus isolation yet. At first, we evaluated various methods for Dengue virus isolation. The result indicate that the best method of RNA extraction for dengue virus is the QIAamp&#x00AE; Viral RNA kit manual extraction. There are no apparent differences of the effect for Dengue virus RNA isolation between filting film and magnetic bead method. Furthermore, DHF caused by Dengue virus is a very serious disease and the pathologic mechanism of DHF has not been elucidated completely. Both clinical and experimental trials have confirmed that the liver cell is one of the target infected by Dengue virus. And, the mechanism of Dengue virus-induced liver cell apoptosis remains poorly understood.Furthermore, there are free radical and cytokines production in patient¡As serum in the acute phase of DF. Therefore, the role of antioxidant and p21 in the mechanisms should be elucidcited. Our preliminary data show that p21 mRNA expression increase in HepG2 after Dengue virus infection. NAC, GSH, and DPI all can attenuate Dengue-induced cell apoptosis. Howerer, the relationship between p21 expression and liver cell apoptosis should be further clarified in the near future.

Thesis (Ph. D.)--West Virginia University, 2002. / Title from document title page. Document formatted into pages; contains xv, 145 p. : ill. (some col.). Includes abstract. Includes bibliographical references (p. 122-145).

Thesis (PhD.(Food Science))-University of Pretoria, 2009. / Includes English summary. Includes bibliographical references.

Obesity is considered an underlying risk factor for metabolic disease including cardiovascular disease (CVD) and diabetes. The fractions containing flavonols from apple peel were evaluated for their antioxidant, anti-inflammatory, and hypolipidemic properties using in vitro and in vivo experimental model systems. The fractionated polyphenolics from apple peels showed a strong antioxidant property protecting against heat-induced oxidation of polyunsaturated fatty acids present in fish oil. Apple flavonols (AF), eicosapentaenoic acid (EPA) and the isoquercitrin-EPA ester (QE) significantly reduced serum triacylglycerols and elevated the high density lipoprotein (HDL)-cholesterol compared to the high fat control group. C-reactive protein and interleukin-6 were also reduced compared to the high fat control group and inflammation induced by lipopolysaccharides. Serum adiponectin and interferon-? concentrations were significantly altered by QE treatment. Overall, AF and QE exhibited anti-inflammatory and hypolipidemic effects under in vivo conditions. These beneficial physiological properties and mode of action of AF and QE need to be further investigated.