Thesis (MSc. (Chemistry)) -- University of Limpopo, 2016 / In this study, antioxidant activity methodologies were evaluated in terms of analytical performances. The total antioxidant activity from Athrixia phylicoides leaves (Bush tea) determined using 2,2-diphenyl-1-picrylhydrazyl radical scavenging (DPPH•) method, cupric ion reducing power (CUPRAC) method and cyclic voltammetry (CV). Folin-Ciocalteu method was used to quantify total phenolic content (TPC) in Athrixia phylicoides leaves. The influence of chemical and physical parameters on the total phenolic content and antioxidant activity determination were investigated. Results from direct sample and crude sample were compared. Antioxidant activity and phenolic content from Athrixia phylicoides leaves were compared with those from commercialised green tea, black tea and rooibos tea using two chosen antioxidant capacity method with acceptable characteristics. Results from the evaluation of the methods demonstrated excellent recoveries (99 to 103%) consistently, good linearity within the calibration concentration range (R2 = 0.997) and repeatable low coefficient of variation < 5% were indicative of good precision except for CV method. The average total antioxidant activity of various extracts of Athrixia phylicoides leaves ranged from 0.039 to 0.122 mg/mL (EC50), 0.031 to 0.233 mg/mL (EC50) and 339 to 429 mV (anodic potential) for DPPH method, CUPRAC method and CV method, respectively. The total antioxidant activity values for each Athrixia phylicoides samples determined by CUPRAC method were higher than the values produced by DPPH and CV methods. The highest antioxidant activities in the DPPH and CUPRAC methods were found in water extracts (direct sample). However, concentrated samples for DPPH method and CV gave a different trend with the methanol extract (crude sample) displaying the highest antioxidant capacity. Increasing the infusion time only increased total antioxidant activity determined by CUPRAC method, whilst DPPH and CV methods had the highest antioxidant activity in the lowest infusion time (3 min). Even though the results are inconclusive with regard to the effect of solid to solvent ratio effect on the total antioxidant activity, 1:150 ratio and 1:100 ratio extracts for both CUPRAC and DPPH methods and for CV gave the highest antioxidant capacities, respectively. The total antioxidant activities in pure antioxidant standards and in the teas were ranked in the following order by both CUPRAC and DPPH methods: Quercetin > catechin > Trolox and Chinese green tea > Joko black tea > Athrixia phylicoides leaves > Laager rooibos tea, respectively. Comparative study showed the necessity of employing more than one method, as each method for the same sample yielded different results. CUPRAC and DPPH methods displayed higher sensitivity and repeatability as compared to the CV method with poor precision.

Thesis (Ph. D.)--University of Texas at Austin, 2006. / Vita. Includes bibliographical references.

In Canada, colorectal cancer is the second leading cause of death from cancer in men and the third leading cause of death from cancer in women. Several factors contribute to the development of cancer. Genetic predisposition, diet, and lifestyle habits are some of the major factors for colorectal cancer development. In the diet related factors, epidemiological studies suggest that consumption of whole grains rich in dietary fiber are associated with low incidence of human colon cancer. Recent studies have also shown that, in addition to dietary fiber, the type of dietary fiber and other compounds such as phenolic acids present in cereal grain bran may also have a role to play in colon cancer prevention. In a recent study, eleven major phenolic acids which differed in anti-oxidant activity were identified in wheat bran from wheat varieties belonging to six different market classes. The main objective of this study was to develop an in vitro cell culture based assay system to study the effect of phenolic acids on colon cancer development. Another objective was to study the effect of phenolic acids on selected molecular markers associated with cell proliferation, apoptosis and inflammation. Two well established colon carcinoma cell lines HT-29 and HCT 116 were treated with varying concentrations of fourteen phenolic acids to study their effect on cell survival and proliferation. In addition, immunohistochemical assays were performed on treated cells for two cell proliferation markers (Cyclin D1 and Ki67), an apoptosis marker (Bax) and three inflammatory markers (Beta-catenin, COX-2 and iNOS). Treatment of phenolic acids inhibited the growth of both the cell lines, however the effects varied with phenolic acid and cell line used in the assay. As determined by IC50, the growth of HCT 116 cells was inhibited the most by caffeic, ellagic, and gallic acids with IC50 of 0.22 mM, 0.17 mM, and 0.15 mM, respectively. On the other hand, caffeic, chlorogenic, and gallic acids are most effective in preventing the growth of HT-29 cells, with IC50 at 0.06 mM, 0.28 mM, and 0.30 mM, respectively. Immunohistochemical and Western Blotting studies revealed that phenolic acids differentially affected markers for cell proliferation, apoptosis and cell inflammation. In most of the cases, phenolic acid treatments up-regulated the pro-apoptosis marker Bax, while it down-regulated cell proliferation marker Cyclin D1. The results clearly show that a cell culture based assay can be used to study the effect of phenolic acids or other chemical constituents isolated from plants to study their effect on colon cancer cell lines. Statistical analysis revealed that only in very limited cases, results of molecular markers correlated to cell growth and proliferation. Therefore, to draw firm conclusions, more detailed and extensive studied need to be completed using different phenolic acids, the two cell lines and more replications. However, this study has developed the necessary protocols and provided some indicative results such as most of the phenolic acids induced pro-apoptosis pathway in both the colon cancer lines. Future studies with extracted phenolic acids from wheat bran using the cell culture system optimized in this study can be used to define the role of different wheat varieties in colon cancer prevention.

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Made available in DSpace on 2014-06-11T19:26:19Z (GMT). No. of bitstreams: 0 Previous issue date: 2012-06-29Bitstream added on 2014-06-13T19:25:33Z : No. of bitstreams: 1 paracatu_lc_me_arafcf.pdf: 657634 bytes, checksum: 11ed69514067f35e0f7dba9e2f7ec13c (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Universidade Estadual Paulista (UNESP) / A ação patogênica do Helicobacter pylori envolve a colonização do trato gastrointestinal e a produção de EROs por neutrófilos atraídos e ativados pelo agente da infecção. A reação mediada pelos PMN é, todavia, ineficaz para eliminar o H. pylori e as EROs contribuem para a lesão tecidual e desenvolvimento de gastrites e úlcera péptica. O ácido cafeico é um dos mais importantes compostos fenólicos, e apresenta diferentes propriedades biológicas, entre elas antioxidante e antimicrobiana. O objetivo deste estudo foi avaliar a atividade antioxidante e anti-H.pylori do ácido cafeico e seus ésteres. Foram avaliados os ésteres: cafelato de metila, cafelato de butila e cafelato de heptila e realizada uma comparação entre as propriedades antioxidantes do ácido cafeico e tais ésteres, por meio de ensaio de quimiluminescência dependente de luminol e lucigenina, ensaio de inibição da produção do ácido hipocloroso e também ensaios morfológicos com e sem a presença de NBT. Os resultados deste estudo mostraram que os ésteres do ácido cafeico apresentaram melhores resultados em comparação com o ácido cafeico para a capacidade antioxidante. O cafelato de heptila apresentou os melhores resultados para a quimiluminescência dependente de luminol e lucigenina induzida por H. pylori e/ou zymozan opsonizado na concentração de 10 µM e 1 µM . O efeito do ácido cafeico e seus ésteres, também foi estudado na inibição da produção de ácido hipocloroso por neutrófilos ativados com PMA. O cafelato de heptila novamente provou ser melhor em capacidade antioxidante, levando a crer que a lipofilicidade deste composto... / The pathogenic action of Helicobacter pylori involves the colonization of the gastrointestinal tract and ROS production by neutrophils attracted and activated by the agent of infection. However, the reaction mediated PMN is ineffective to remove the H. pylori and ROS contribute to tissue damage and development of gastritis and peptic ulcer. Caffeic acid is one of most important phenolic compounds, and has different biological properties including antioxidant and antimicrobial activities. The aim of this study was to evaluate the antioxidant and anti-Helicobacter pylori activity of caffeic acid and esters. Esters evaluated: methyl caffeic acid ester, butyl caffeic acid ester and heptyl caffeic acid ester and a comparison between the antioxidant properties of caffeic acid and these esters through luminol and lucigenin chemiluminescence assay dependent, inhibition of production of hypochlorous acid assay, morphological tests with and without the presence of NBT. The results of this study showed that the esters of caffeic acid had better results in comparison with caffeic acid to their antioxidant capacity. The heptyl caffeic acid ester showed the best results for the luminol and lucigenin dependent chemiluminescence induced by H. pylori and / or opsonized zymozan in the concentrations of 10 µM and 1 µM. The effect of caffeic acid and esters, was also studied in inhibiting of production of hypochlorous acid by neutrophils activated with PMA. The heptyl caffeic acid ester again proved to be better at antioxidant activity, implying that... (Complete abstract click electronic access below)

CHARLES UNIVERSITY PHARMACEUTICAL FACULTY IN HRADEC KRÁLOVÉ DEPARTMENT OF PHARMACEUTICAL BOTANY Title of the Diploma thesis: FENOLIC ACIDS IN PLANTS Candidate: Lucie Klížová Supervisor: PharmDr. Jana Karlíčková, Ph.D. Diploma thesis 2020/2021, pp. 153 Phenolic acids belongs between secondary metabolites, which are part of fruits, vegetables, cereals and other plants of different families. For example, it can be plants of family Lamiaceae, Asteraceae and Ericaceae, which contain significant amounts of these substances. In plants phenolic acids play an important role and they have many human health-promoting effects including antioxidant, anti-inflammatory, antiviral, antibacterial, antifungal, anticancer activity and other. Plants containing phenolic acids are preferably also used as antidiabetics, expectorants, insecticides, hypolipidemics, cardioprotective and neurological compounds, etc. The content of these compounds in plants may be different according to monitored cultivar, the place of growth, the time of harvest and many other aspects. Presence, identification and subsequent quantification of individual phenolic acids are usually done through the HPLC and MS methods and total content of these compounds is determined through the Folin-Ciocalteu method. The diploma thesis is a literature...

The aim of this research was to investigate the phytochemistry of two species Sanicula europaea and Teucrium davaeanum which are traditionally used in treatment of wounds. Four compounds were isolated from the 80% methanolic extract of S. europaea; bis-(2-ethylhexyl) phthalate (1), palmitic acid (2), rosmarinic acid (3), saniculoside N (4). Compounds 1 and 2 were isolated for the first time from this species. The structure elucidation of the isolated compounds was on the basis of 1D, 2D NMR spectroscopy and mass spectrometry measurements. Two compounds were isolated from the crude glycosides extract of T.davaeanum; 6 is a phenylethanoid glycoside and 8 is an iridoid glycoside, from the data available these may be new compounds for which the names davaeanuside A and davaeanuside B are proposed respectively." The total polyphenol content of S. europaea L, T. davaeanum leaves-flowers and T. davaeanum stem were found to be 5.0, 1.20 and 0.65 mg per 100 mg dried plant material respectively. A study of the antioxidant activity of the 50 % ethanol extracts of S. europaea and T. davaeanum showed that on a mg/mg basis S. europaea and T. davaeanum have approximately 5%, 8 % antioxidant capacity of Trolox respectively. A study of the cytotoxic activity of davaeanuside A (6), iridoid glycoside (7), davaeanuside B (8) and saponin compound (10) isolated from the crude glycosides extract of T. davaeanum revealed that saponin compound (10) inhibited the growth of Hela cells by 50 % at 50 μg/ml, P< 0.001, but the other compounds did not show activities against the tested cell lines at 100 μg/ml. The results of this work provide some basis for the traditional use of these species in the treatment of wounds. / Ministry of high education in Libya

<p>U okviru disertacije ispitana je mogućnost eksploatacije nusproizvoda (nastalih tokom procesa hladnog presovanja ulja) kao izvora prirodnih fenolnih kiselina. Odabir je obuhvatio uzorke uljane tikve, crnog kima, lana i nara. Radi oslobađanja vezanih fenolnih kiselina i u cilju procene njihovog ukupnog sadržaja i distribucije (u čvrstim uzorcima), primenjena je alkalna hidroliza sa dodatkom L-askorbinske kiseline i EDTA. Dobijeni rezultati pokazuju da se sve analizirane pogače mogu se koristiti za dobijanje vrednih fenolnih kiselina, pri čemu raspodela fenolnih kiselina zavisi od vrste uljane pogače. Koncentracija slobodnih fenolnih kiselina se pokazala značajnom za pogaču uljane tikve, estarski vezanih za pogače nara i lana, a nerastvornih-vezanih za pogače crnog kima i nara. Od svih analiziranih uzoraka kora nara je sadržala najvi&scaron;e estarski vezanih fenolnih kiselina zahvaljujući veoma visokom sadržaju galne kiseline. Nakon određivanja fenolnih kiselina u nusproizvodima, analiza glavnih komponenti (PCA) je omogućila razdvajanje biljnih uzoraka u grupe prema poreklu i smanjila broj fenolnih kiselina neophodnih za njihovu karakterizaciju, &scaron;to može imati potencijalnu primenu u skriningu fenolnih kiselina i određivanju kvaliteta/autentičnosti uljarica i njihovih nusproizvoda.</p> / <p>Within the thesis, the possibility of by-products (formed during the process of cold oil pressing) exploitation as a source of natural phenolic acids was examined. Selection of the samples included pumpkin, black cumin, flax and pomegranate. For the purpose of bonded phenolic acids release and for the total phenolic acids content and distribution (in the solid samples) assessment, the alkaline hydrolysis with the addition of L-ascorbic acid and EDTA was employed. The results show that all analyzed cakes can be used to obtain valuable phenolic acids, while the distribution of phenolic acids depends on the type of oil cakes. The concentration of free phenolic acids proved to be significant for a pumpkin oil cake, ester for pomegranate and flax oil cakes, and insoluble-bound for black cumin and pomegranate oil cakes. Of all analyzed samples, pomegranate hull contains the highest content of ester-linked phenolic acids, due to a very high content of gallic acid. After phenolic acids determination in the by-products, principal components analysis (PCA) allowed the separation of plant samples in groups according to origin and reduced the number of phenolic acids necessary for their characterization, which may have potential application in the screening of phenolic acids and determining the quality/authenticity oilseeds and their by-products.</p>

Os antioxidantes de origem natural têm importância na área de alimentos, pois podem representar uma alternativa de substituição aos antioxidantes sintéticos. Os compostos fenólicos, presentes nos vegetais, desempenham importância na inibição da oxidação, A romã (Punica granatum, L.) é rica em compostos fenólicos como as antocianinas, flavonóides e ácidos fenólicos. Avaliou-se a atividade antioxidante da polpa e semente de romãs plantadas no Brasil (Pernambuco), e foi feita a obtenção dos extratos e frações de ácidos fenólicos da fruta, que foram submetidos aos testes de co-oxidação de substratos &#946;- caroteno e ácido linoléico, em meio emulsionado, e ao método Rancimat, em meio lipídico. Também foi avaliado o comportamento cinético da atividade antioxidante para os extratos e frações de ácidos fenólicos. Verificou-se que os extratos aquosos da polpa e semente apresentaram significativa inibição da oxidação a concentrações baixas, em ambos os testes utilizados, fato atribuído à grande quantidade de compostos fenólicos presentes nestes extratos, em relação aos demais. A avaliação cinética dos extratos aquosos demonstrou que estes também foram mais eficientes ao longo do processo oxidativo, apresentando-se mais estáveis do que o antioxidante sintético BHT. As frações de ácidos fenólicos esterificados a compostos solúveis da polpa foi a fração que apresentou maior inibição da oxidação, e também maior quantidade de compostos fenólicos, apresentando uma atividade cinética bastante eficiente. Entretanto, as frações de ácidos fenólicos livres da polpa e semente apresentaram porcentagens de inibição da oxidação bastante altas a uma concentração menor. A semente da romã apresenta em sua composição de ácidos graxos o ácido graxo punícico. Este ácido é um isômero conjugado do ácido linolênico, e que constitui 58% da composição total de ácidos graxos da semente da fruta, sendo seu principal ácido graxo. / The antioxidants of natural origin have an important role on food science, because they may substitute the synthetic antioxidants. The phenolic compounds of vegetables play an important role as oxidation inhibitors. The pomegranate (Punica granatum, L.) is rich in phenolic compounds as anthocianins, flavonoids and phenolic acids. The antioxidant activity of extracts and acid phenolic fractions obtained from the pulp and seeds of brazilian pomegranate (from Pernambuco) was evaluated, by the co-oxidation of &#946;-carotene and linoleic acid assay and the Rancimat method. The kinetic behavior of the antioxidant activity of the extracts and acid phenolic fractions by the co-oxidation of &#946-carotene and linoleic acid test was evaluated, too. It was noted that the aquous extracts from the pulp and seeds have significant antioxidant activity at slow concentration. It was possible by the high content of phenolic compounds present on those extracts. The kinetic behavior showed that the aquous extracts was the most efficient along the oxidative process, showing larger stability than the antioxidant BHT. The pulp\'s of bound acid phenolic fraction by soluble compounds was the most efficient among the acid phenolic fractions, and it has major amount of phenolic compounds. The pomegranate seed has the punicic acid on its fatty acid composition. The punicic acid is a I conjugated inolenic acid isomer.The punicic acid is present at 58% from the total fatty acids from the fruit, being its principal fatty acid.

Os radicais livres são formados constantemente em nosso organismo, e em quantidades controladas desempenham alguns papéis fisiológicos. Entretanto, sua presença em quantidades acima daquelas aceitáveis passa a ser um fator de risco para funcionamento adequado do organismo. Muitas doenças crônicas degenerativas têm sua origem no desequilíbrio do estado redox. Apesar de possuir um sistema de proteção antioxidante endógeno, o organismo pode ser beneficiado pela presença de compostos antioxidantes exógenos, como os compostos fenólicos encontrados em alguns alimentos. A romã (Punica granatum, L) é uma fruta que apresenta elevados conteúdos destes compostos. Foram obtidos os extratos e as frações de ácidos fenólicos da polpa e das sementes da fruta, e avaliou-se a capacidade antioxidante através de três métodos in vitro: o de co-oxidação de substratos (&#946;- caroteno e ácido linoléico), o do radical DPPH&#8226; e o ORAC. Em todos os testes foram obtidos resultados que indicaram uma elevada atividade antioxidante, principalmente para a fração de ácidos fenólicos livres (AFL) da polpa. Frente a estes dados, a fração foi submetida a um ensaio de transporte celular, o qual foi possível verificar que os diferentes ácidos fenólicos ali encontrados foram capazes de atravessar a membrana celular. A fração AFL da polpa propiciou uma redução na produção de espécies reativas intracelulares e efeitos sobre a proliferação e a viabilidade em células das linhagens Caco-2, HeLa e MDCK. Por fim, o ensaio in vivo avaliou, sob condições fisiológicas normais, o efeito do extrato aquoso e da fração AFL sobre a oxidação lipídica e na atividade do sistema enzimático de defesa antioxidante. O tecido cerebral apresentou uma redução significativa nos níveis de lipoperoxidação. A atividade das enzimas superóxido dismutase, catalase e glutationa peroxidase apresentou resultados bastante díspares e sugerem que as respostas não seguem um padrão único e podem variar de acordo com o órgão analisado, respondendo com o aumento ou a diminuição da atividade enzimática de acordo com suas funções fisiológicas. / Free radicals are continuosly formed in our organism, and under suitable amounts they play physiological roles. However, when there´s a higher presence in their levels than the acceptable ones, they turn into a risk factor to the adequate work of the organism. Most of the degenerative illness are originated from the redox state desequilibrium. Although the organism has an endogenous antioxidant defence system, it may be beneficiated by the presence of antioxidant compounds of exogenous origen, as the phenolic compounds that are found in some kinds of food. The pomegranate (Punica grantum, L.) is a high phenolic compound fruit. The extracts and phenolic fractions both from the pulp and seeds of the fruit were obtained and their antioxidant activity was obtained using three in vitro methods: the co-oxidation of substrates (&#946;-carotene and linoleic acid), the DPPH&#8226; radical and the ORAC. For all of them the results have showed a great antioxidant activity, higher than those of the free phenolics acids´fraction (FPA) of the pulp. Face to these data, the fraction was taken to a cellular transport assay, which was possible to verify that the different phenolic acids present at FPA were able to cross the cellular membrane. The FPA pulp´s fraction provocated a down in production of the the intracelular reactive species and had effects into the cellular proliferation and viability of the Caco-2, HeLa and MDCK cells. Finally, the in vivo tryout was made using rats submitted to normal physiologic conditions and the effects of the aquous extract and FPA fraction over the lipidic oxidation and the activity of the enzymatic system of antioxidant defence were avaliated. The brain tissue showed a significant reduction about the lipoperoxidation levels. The results about the activity of the enzymes superoxide dismutase, catalase and glutathione peroxidase were so different between themselves, which suggests that the enzymes don´t follow an only standard of response, and the reply can vary in accordance with the analyzed organ. The increase or the reduction of the enzymatic activity can occur by the physiologic conditions that the organ is able to do.