Thesis submitted in fulfilment of the requirements for the degree Master of Technology: Consumer Science: Food and Nutrition in the Faculty of Applied Sciences at the Cape Peninsula University of Technology 2014 / The prevalence of nutrition-related chronic diseases of lifestyle (CDL) is escalating in South Africa (SA). Studies suggest that poor nutrition plays a major role in the aetiology of these diseases. Phytochemicals present in plant foods, namely fruit, vegetables, whole grains and tea, may prevent the onset of CDL. Most South African diets appear to be deficient of these plant foods. Achieving enhanced phytochemical intake amongst South Africans may therefore have to be supported in other ways. The objectives of this research were to determine whether consumers in the professional sector in the City of Cape Town would be (i) likely to consume proficient home-cooked category prepared dishes and (ii) purchase and consume commercially manufactured category prepared dishes for enhanced phytochemical intake and, if so, (iii) which dietary source adjustment category/categories and (iv) food vehicle category/categories they would be likely to consume, and (v) who would be likely to consume them. After obtaining ethical approval, a survey was conducted amongst 184 white collar workers (87% response rate) representing the professional sector (professional, technician and associate professional) occupational groups. The respondents were approached for voluntary participation based on their occupation and age, representing adulthood to the elderly life stage as a risk factor for the development of lifestyle diseases. A pilot-tested questionnaire was used to obtain information regarding the respondents awareness of phytochemicals, whether or not they were involved in the preparation of food at home, their degree of ‘likelihood’ to consume proficient home-cooked and commercially manufactured category prepared dishes for enhanced phytochemical intake, their current daily intake of fruit, vegetables, whole grains and tea, and demographic, health and lifestyle information. The frequencies of the respondents’ consumption of phytochemical-rich dietary sources pertaining to the stages of change model were assessed using Pearson’s chi-squared analysis to determine significant associations/differences (p < 0.05) between the data sets. The repeated measure analysis of variance (ANOVA) on Bonferroni correction was used to assess the ‘likeliness’ scale (from ‘extremely unlikely’ as ‘1’ to ‘extremely likely’ as ‘5’) for the household and commercial dietary source adjustment and food vehicle categories. The respondents were mostly female (58.7%), 31 to 44 years of age (67.9%) and of White ethnicity (72.3%). The majority (61.5%) had obtained grade 12 and a diploma (29.4%) or a degree (32.1%). Almost half were married or living together with children (48.9%) and were English (48.9%) or Afrikaans (47.3%) speaking. The majority of respondents were non-smokers (69%), and approximately half (54.4%) consumed alcohol less than three times per week (54.4%). About fifty percent used dietary supplements (50.5%) and exercised (59.2%) regularly. A small percentage of the respondents were obese (7.6%), had diabetes mellitus (4.4%) or cardiovascular disease (CVD) and cancer (2.2% or four respondents each). Cancer was most prevalent (36.4%) within the respondents’ family, followed by diabetes mellitus (29.9%), CVD (26.6%) and obesity (7.6%). The majority (77.7%) were not aware of phytochemicals and about half (55.4%) could not indicate the role these compounds play in the human diet. Half of the respondents consumed the recommended two to four servings of fruit daily, very few (10.9%) consumed the recommended three to five servings of vegetables daily, only about 10% (9.2% or 17 respondents) consumed the recommended three servings of whole grains daily, and about a third (36.4%) consumed two to three cups of tea daily. The respondents who considered phytochemicals to be very necessary to support health were more likely to consume rooibos herbal tea added to category prepared dishes than those who considered phytochemicals to be necessary to support health (p < 0.05) and those who did not know the role phytochemicals played in the diet (p < 0.05). The likelihood to consume category prepared dishes with added vegetables and added fruit respectively was lower (p < 0.05) amongst those respondents who consumed none to one serving of vegetables daily than amongst those who consumed two to four servings of vegetables daily. The respondents who did not consume tea were less likely to consume category prepared dishes with added rooibos herbal tea than those who consumed one cup (p < 0.05) or two to three cups (p < 0.001) daily. Furthermore, the respondents who did not consume tea were also less likely to consume category prepared dishes with added herbs than those who consumed one cup (p < 0.05), two to three cups (p < 0.001) or four to six cups (p < 0.05) daily. The likelihood to consume category prepared dishes with fruit additions was lower amongst those respondents who did not consume tea than amongst those who consumed two to three cups (p < 0.05) or four to six cups (p < 0.05) daily. The respondents were more likely (p < 0.05) to consume herb, vegetable and fruit additions respectively than rooibos herbal tea addition, and more likely to consume vegetable additions than herb (p < 0.05) or fruit (p < 0.001) additions as dietary source adjustment options. Furthermore, vegetable additions to category prepared dishes were more likely to be consumed by the respondents than fruit additions (p < 0.001), and starch-based dishes more likely to be consumed than vegetable-based dishes (p < 0.001) or fruit-based dishes (p < 0.05) for the addition of rooibos herbal tea. The respondents were likely to consume the food vehicle categories egg and chicken for added herbs in comparison to other starch (p < 0.05) and vegetables (p < 0.001) respectively. Chicken was a likely option over pasta for added broccoli (p < 0.05). Crêpe was a likely option over compote for added mixed berries (p < 0.001). Potato was a likely option over vegetables (p < 0.05) as well as other starch over vegetables (p < 0.05) for added herbs. Carrot salad with raisins was a likely option above carrot salad with raisins and parsley (p < 0.05). Poached pear in red grape juice was a likely option over poached pear in rooibos herbal tea (p < 0.001). Tomato (p < 0.001) and broccoli (p < 0.05) were more likely to be consumed than spinach, while spinach (p < 0.05) and roasted butternut (p < 0.05) respectively were likely options over onion as vegetables added to a quiche. Onion was a less likely option over broccoli (p < 0.001), tomato (p < 0.001) and roasted butternut (p < 0.001) as respective vegetables in a soup. Tomato soup was a likely option over tomato soup with rooibos herbal tea (p < 0.001). Roasted butternut soup was a likely option over butternut and orange soup (p < 0.001) and butternut and rosemary soup (p < 0.001). Berries as fruit addition were a likely option over pome fruit as pear (p < 0.05) and citrus fruit (p < 0.001), and furthermore citrus fruit over pome fruit as pear (p < 0.05). Raw apple with its skin on was a more likely option over chicken breast salad with apple pieces (p < 0.001), and chicken breast salad with apple a likely option over chicken and apple casserole (p < 0.001). Parsley was a likely option over basil (p < 0.001), and mixed herbs (p < 0.001) and rosemary (p < 0.001) respectively were likely options over basil as herb addition. Commercially manufactured category prepared dishes likely to be purchased and consumed by the respondents included category prepared dishes with added fibre more than added herbs (p < 0.05), fruit (p < 0.001), vegetables (p < 0.001) or tea (p < 0.001), and added herbs than added vegetables (p < 0.05) or tea (p < 0.05). Pizza/pasta was a likely option over beverages (p < 0.05), grains/bake (p < 0.001) and dairy (p < 0.001) respectively, and baked goods than grains/bake (p < 0.001), dairy (p < 0.001) and beverages (p < 0.05) respectively as food vehicles. A baked dish with added fibre was more likely to be consumed than with added fruit (p < 0.001), tea (p < 0.001) or vegetables (p < 0.001), and added fruit more likely to be consumed than added vegetables (p < 0.05). Pasta incorporating vegetables was a more likely option than pasta incorporating fruit (p < 0.001). Shortbread with added fruit was a likely option over added herbs (p < 0.05), and a muffin with bran (p < 0.001) or blueberries (p < 0.001) a likely option over a muffin with spinach. Fruit juice incorporating rooibos herbal tea (p < 0.001) or herbs (p < 0.001) were likely options over fibre incorporation. The female respondents were more likely to consume category prepared dishes with added fruit than the male respondents (p < 0.05), while the older respondents (55 to 64 years) were more likely to consume category prepared dishes with added herbs than the younger respondents (31 to 44 years) (p < 0.05). The older respondents were also more likely to consume category prepared dishes with fruit additions than the younger respondents aged 31 to 44 (p < 0.05) and 45 to 54 (p < 0.05) respectively. The respondents involved in the preparation of food at home were more likely to consume category prepared dishes with the addition of rooibos herbal tea (p < 0.05), herbs (p < 0.05) and fruit (p < 0.05) respectively than those who were not involved in preparing food at home.

Fruits and vegetables are known to play an important role in human health due to the range of phytochemicals they contain. Twenty-one peach genotypes and 45 plum genotypes with different flesh and skin color were analyzed for their antioxidant content and antioxidant activity. Anthocyanin content, phenolic content and antioxidant activity were higher in red-flesh than in light-colored flesh peaches. Carotenoid content was higher in yellow-flesh peaches. Among the peaches, the antioxidant activity was well correlated with phenolic content. The anthocyanin content among the plums increased with the red color intensity. Red-flesh plums generally had higher phenolic content than the other plums. Antioxidant activity was higher in red-flesh genotypes; however, it was strongly correlated only with the phenolic content in light-colored flesh plums. Extracts from selected genotypes of peaches and plums and their fractions were evaluated against two breast cancer cell lines (MDA-MB-435 and MCF-7) and one non-cancerous breast line (MCF-10A). The cells were cultured in the presence of peach and plum extracts and their fractions at various concentrations (0-500 µg/ml) and the cell viability and antiproliferation activity was evaluated by MTT assay and Coulter Counter. There was a dose-dependent reduction on cell viability of estrogen-negative MDA-MB-435 breast cancer cells. Only weak activity against MCF-7 was observed at high extract concentrations. There was no activity against MCF-10A after 24 h treatment. Fraction I, which consists of mainly phenolic acids such as chlorogenic acid and a caffeic acid derivative, reduces MDA-MB-435 breast cancer cell viability with the lowest IC50. The second most effective fraction was Fraction II which contained anthocyanins. Fraction III (flavonols) and Fraction IV (polymerized compounds) had no effect on the cell lines. Phenolic acids present in fraction I induced apoptosis in MDA-MB-435 estrogen receptor-negative cell line. Fraction I did not induced apoptosis in MCF-10A, a noncancerous cell line even at higher concentrations than the ones tested in MDA-MB- 435. Apoptosis induced by Fraction I was caspase 3 and PARP independent. After treatment with 50 µg of chlorogenic acid equivalent/ml there was an activation of p- ERK.

Secondary plant metabolites have recently been gaining interest in livestock production systems following the ban of in-feed antibiotics within the European Union. The rise in antimicrobial resistance found in pathogenic and non-pathogenic bacteria has lead to increased interest in the research community regarding the use of phythochemicals as an alternative to antibiotics. The purpose of this research was to evaluate the impact of including phytochemicals in a livestock production system. Specifically, a high tannin-containing forage, sainfoin (Onobrychis viciifolia), was evaluated in vitro for its antimicrobial effect on Escherichia coli. We determined that phytochemicals alone are not as inhibitory as synthetic antibiotics. Thus, the use of combination therapy to deter the development of antimicrobial resistance was evaluated. A myriad of plant compounds were screened for their synergistic interactions with ciprofloxacin. Geraniol, an essential oil, was identified to possess good antimicrobial activity and synergistic interactions with ciprofloxacin. Therefore the effect of long term exposure to both ciprofloxacin and geraniol were examined. Results demonstrated that once an antimicrobial concentration threshold was reached, resistance to ciprofloxacin increased markedly in the presence of both geraniol and ciprofloxacin. Finally, an in vivo trial was conducted in which forty steers were fed sainfoin or alfalfa over a 9-week period to evaluate its ability to reduce E. coli shedding and its impact on gut microbiota in the context of popular theoretical ecology concepts. Results from the in vivo study indicate that sainfoin was able to promote a slight decrease in generic E. coli shedding which could be maintained throughout the trial. Using high-throughput sequencing, the effect of sainfoin on the microbial ecosystem of the ruminant gut was evaluated. Sainfoin induced a significant shift in the microbial community structure of the rumen and to a lesser extent in the hindgut. Using ecology theories, a hypothesis was formulated regarding the mechanisms that mediate the development of tolerance and the fundamental ecological processes controlling microbial population shifts. Understanding how the gut ecosystem functions and predicting its behaviour in the presence of various fluctuating environmental conditions will enable more efficient manipulation of the rumen and promote best management practices in livestock production.

Secondary plant metabolites have recently been gaining interest in livestock production systems following the ban of in-feed antibiotics within the European Union. The rise in antimicrobial resistance found in pathogenic and non-pathogenic bacteria has lead to increased interest in the research community regarding the use of phythochemicals as an alternative to antibiotics. The purpose of this research was to evaluate the impact of including phytochemicals in a livestock production system. Specifically, a high tannin-containing forage, sainfoin (Onobrychis viciifolia), was evaluated in vitro for its antimicrobial effect on Escherichia coli. We determined that phytochemicals alone are not as inhibitory as synthetic antibiotics. Thus, the use of combination therapy to deter the development of antimicrobial resistance was evaluated. A myriad of plant compounds were screened for their synergistic interactions with ciprofloxacin. Geraniol, an essential oil, was identified to possess good antimicrobial activity and synergistic interactions with ciprofloxacin. Therefore the effect of long term exposure to both ciprofloxacin and geraniol were examined. Results demonstrated that once an antimicrobial concentration threshold was reached, resistance to ciprofloxacin increased markedly in the presence of both geraniol and ciprofloxacin. Finally, an in vivo trial was conducted in which forty steers were fed sainfoin or alfalfa over a 9-week period to evaluate its ability to reduce E. coli shedding and its impact on gut microbiota in the context of popular theoretical ecology concepts. Results from the in vivo study indicate that sainfoin was able to promote a slight decrease in generic E. coli shedding which could be maintained throughout the trial. Using high-throughput sequencing, the effect of sainfoin on the microbial ecosystem of the ruminant gut was evaluated. Sainfoin induced a significant shift in the microbial community structure of the rumen and to a lesser extent in the hindgut. Using ecology theories, a hypothesis was formulated regarding the mechanisms that mediate the development of tolerance and the fundamental ecological processes controlling microbial population shifts. Understanding how the gut ecosystem functions and predicting its behaviour in the presence of various fluctuating environmental conditions will enable more efficient manipulation of the rumen and promote best management practices in livestock production.

Thesis (Ph. D.)--Ohio State University, 2006. / Title from first page of PDF file. Includes bibliographical references (p. 186-198).

Tender coconut water (TCW) is one of most consumed natural energy drinks. Although it is widely available in tropical countries, because of its natural health benefits it is increasingly consumed in other parts of the world. Therefore there has been an increased requirement for packaging and shipping. TCW is highly susceptible to microbial contamination during extraction and packaging, requiring pasteurization. Thermal pasteurization leads to loss of flavor and color of coconut water. The purpose of this study was to test the feasibility of a non-thermal method of pasteurization of TCW using natural antimicrobials like curcumin, eugenol, and d-limonene with curcumin. The non-thermal pasteurization method was developed in two different processes, i.e. a batch and flow-filter process. Batch cold pasteurization process was conducted by suspending liposome encapsulated antimicrobials immobilized on glassbeads in TCW at 4oC by shake flask assay. Maximum Reduction of Listeria monocytogenes and Escherichia coli W1485 in pasteurized TCW were observed to be 5 log CFU per ml of TCW within 7 days of incubation under the presence of nano-liposomes containing 50 mM of curcumin, d- limonene or eugenol. There was no change in color and aroma of TCW after 1 month of storage at 4oC. the flow filter cold pasteurization process was developed using filter medium coated with nano-liposomes encapsulated antimicrobial leading to extended release of the natural antimicrobial curcumin to the coconut water in 4oC. Listeria monocytogenes and E. coli W1485 were used as model organisms to test effectiveness of cold pasteurization. Reduction of L. monocytogenes and E. coli W1485 in pasteurized TCW was observed to be 5.2 and 4.5 log10CFU/ml of TCW respectively within 17.25 min of incubation under the presence of nano-liposomes containing 50 mM of curcumin. There was no change in color and aroma of TCW after 1 week of storage at 4oC.

Natural therapies such as Aged Garlic Extract (AGE) have displayed cardioprotective properties, with studies indicating that AGE can inhibit platelet aggregation both in vivo and in vitro. The mechanism of inhibition induced by AGE is proposed to be due to AGE exerting effects upon several targets within platelets, including calcium and cyclic adenosine monophosphate (cAMP). The effect of AGE upon the other cyclic nucleotide, cyclic guanosine monophosphate (cGMP) is currently unknown. The aims therefore of this project are to identify the effect of AGE upon platelet cGMP, as well as associated signaling molecules including nitric oxide (NO) and cAMP.It was found that the NO donor 3-morpholinosydnonimine (Sin-1) in high concentrations along with the presence of specific inhibitors inhibited platelet aggregation independently of cGMP. Experimentation using chemical inhibitors also displayed erratic results in the presence of high concentrations of AGE, indicating that AGE was influencing the binding of such inhibitors. The results of in vitro experiments indicated that AGE moderately increases intraplatelet cGMP, whereas intraplatelet cAMP is significantly increased. it is proposed that the main mechanism of inhibition caused by AGE is due to increases in cAMP. As intraplatelet cAMP can also be influenced by intraplatelet cGMP, it is likely that cAMP is increased directly and indirectly by AGE.Evidence provided in the present study supports the proposed theory that the mechanisms of inhibition of platelet aggregation by AGE is multimechanistic. More specifically inhibition of platelet aggregation by AGE is due to AGE increasing intraplatelet cyclic nucleotides, reducing the expression of key receptors such as GPIIb/IIIa and inhibiting agonist induced platelet shape change. As AGE can inhibit platelet aggregation, which is a key risk factor in cardiovascular disease, the consumption of AGE would be beneficial to those who are at risk of cardiovascular episodes.

Submitted by GISLENE PARREIRAS COSTA null (giscosta1@hotmail.com) on 2017-05-02T20:25:27Z No. of bitstreams: 1 DISSERTAÇÃO FINALissima IMPRIMIR 02 maio 2017.pdf: 709377 bytes, checksum: 2269ffdcc1be5a2294b7c367a1c7e2cb (MD5) / Approved for entry into archive by Luiz Galeffi (luizgaleffi@gmail.com) on 2017-05-03T20:14:39Z (GMT) No. of bitstreams: 1 costa_gp_me_assis.pdf: 709377 bytes, checksum: 2269ffdcc1be5a2294b7c367a1c7e2cb (MD5) / Made available in DSpace on 2017-05-03T20:14:39Z (GMT). No. of bitstreams: 1 costa_gp_me_assis.pdf: 709377 bytes, checksum: 2269ffdcc1be5a2294b7c367a1c7e2cb (MD5) Previous issue date: 2017-03-07 / O Cerrado, um dos principais biomas brasileiros, tem sofrido sucessivas agressões a sua biodiversidade, ocasionando o desaparecimento de inúmeras espécies com potencial biotecnológico. Dentre as espécies típicas do Cerrado, Annona crassiflora Mart. (Annonaceae), também conhecida como marolo, possui especial importância, principalmente devido à presença de fitoquímicos com ação antioxidante. O presente trabalho teve como objetivo investigar a ação antioxidante e quantificar a presença de fenóis, flavonoides e taninos nos extratos hidroalcoólicos obtidos a partir das folhas e da polpa de frutos de A. crassiflora. Foi possível verificar que o extrato hidroalcoólico obtido a partir das folhas de A. crassiflora apresentou valores de compostos fenólicos, flavonoides e taninos equivalentes aos respectivos padrões (ácido gálico, quercetina e proantocianidinas, respectivamente). Com base nestes resultados, foi produzido e testado, in vitro, um fitocosmético em forma de gel. Com base nos resultados obtidos foi possível concluir que a formulação de um gel enriquecido com este extrato abre a possibilidade do desenvolvimento de um novo fitocosmético com atividade antienvelhecimento. / The Cerrado, one of the main Brazilian biomes, has undergone successive aggressions against its rich biodiversity, causing the disappearance of numerous species with biotechnological potential. Among the typical species of the Cerrado, Annona crassiflora Mart. (Annonaceae), also known as marolo, has special importance, mainly due to the presence of phytochemicals with antioxidant action. The present work had as objective to investigate the antioxidant action and to quantify the presence of phenols, flavonoids and tannins in the hydroalcoholic extracts obtained from the leaves and fruit pulp of A. crassiflora. It was possible to verify that the hydroalcoholic extract of A. crassiflora leaves contain phenolic compounds that can serve as natural sources of antioxidant agents, especially tannins. Based on these results, we produced and testedppp, in vitro, a phytocosmetic in gel form, obtaining very promising results. In this way, the formulation and evaluation of a gel enriched with this extract opens the possibility of the development of a new phytocosmetics with antiaging activity.

M.Sc. (Chemistry) / The extraction of the atropine and scopolamine alkaloids from both Datura ferox and Datura stramonium was carried out in this study to investigate potential of these plants as a source of these alkaloids. Tropane alkaloids such as atropine occur naturally in many members of several plant families, especially the Solanaceae, Erythroxylaceae, Proteaceae and Convolvulaceae families. Hyoscyamine or its racemic mixture atropine is used as an antidote to organophosphate insecticides, or as a nerve agent to dilate the pupil for retina examinations. Scopolamine or hyoscine is used to treat motion sickness, among other uses. Tropane alkaloids are often difficult to synthesise, and their extraction from commercial sources is therefore of some commercial interest. A systematic study was carried by comparing different extraction methods for the efficiencies of tropane alkaloid (TA) extraction at ambient pressure. The two plants selected are already widely spread as weeds in many regions in South Africa and are therefore well adapted to the local conditions. Among the extraction methods, TA’s were extracted in their acidic form using dilute aqueous acids with 5% sulfuric acid giving the highest yield of both atropine and scopolamine. Alternatively, the TA’s were extracted in their basic form from the plant material using basified organic solvents. The overall yields obtained were not significantly different from those obtained by using dilute aqueous acids, with D. ferox giving approximately 0.24 % and 0.0028 % scopolamine and atropine, respectively. D. stramonium on the other hand gave approximately 0.037 % and 0.002% atropine and scopolamine, respectively. Different plant parts were also tested in order to determine if there was an advantage in extracting the tropane alkaloids at a particular time in the growth, but concluded that the best option was to extract the seeds for various reasons such as the presence of relatively less chlorophyll...

Orientador: Patricia da Silva Melo / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Ciências Aplicadas / Made available in DSpace on 2018-08-27T21:30:15Z (GMT). No. of bitstreams: 1 Ferreira_IasminRosanneSilva_M.pdf: 836058 bytes, checksum: 5beb54192fc88a1ebf1ce80d1b2424bd (MD5) Previous issue date: 2014 / Resumo: Compostos encontrados na natureza, mostram uma enorme gama de diversidade em termos de estrutura e atividades farmacológicas. Apesar dos avanços na sintese química, as plantas se mostram cada vez mais eficientes na busca de novos tratamentos contra o câncer. Assim, o objetivo deste estudo foi avaliar seis fitoterápicos pertencentes à classe de lignoides (dimethoxymagnolol, grandisina e iangambina) e riparinas (I, II e III) , com e sem suplementação de glutationa (GSH - 1mM) em três linhagens de células leucêmicas K562, U937 e HL60. A viabilidade celular foi avaliada por ensaio de redução de MTT em células leucemicas tratadas com os fitoquímicos (com ou sem suplementação de GSH). Nas células U937 foram encontrados valores de IC50 de 100 ?M, 30 ?M e 500 ?M em células tratadas com dimethoximagnolol, grandisina e iangambina, respectivamente, e 60, 25 e 15 ?M (riparina I, II e III, respectivamente). Nas células K562, o tratamento com riparinas foi o mais eficaz dos compostos estudados , uma vez que foram determinados valores de IC50 de 125, 27 e 15 ?M ( riparina I, II e III, respectivamente). Diferentes valores foram encontrados em células HL60 tratadas com riparinas (140, 100 e 75 ?M para riparina I, II e III, respectivamente). A suplementação com GSH amenizou apenas os efeitos tóxicos após tratamento das células U937 com riparina II, uma vez que não foram observados resultados diferentes em outras linhagens celulares tratadas com os compostos estudados com a suplementação de GSH. A citotoxicidade desses fitoquímicos também foi avaliada em linhagem de células de fibroblasto de pulmão permanente (V79), que são células de cultura utilizadas para os estudos de citotoxicidade. Todos os fitoquímicos investigados, com exceção da iangambina, foram menos tóxicos para células V79 do que para as células leucêmicas. Estes resultados se mostram positivos, uma vez que a atividade farmacológica foi maior nas células leucêmicas do que nas células V79. Todos os compostos estudados neste trabalho apresentaram efeitos anti-tumorais, no entanto, o mecanismo de ação da riparina II é diferente em células U937 já que a suplementação com GSH foi eficaz contra os efeitos tóxicos. Provavelmente, a riparina II provocou a morte celular por estresse oxidativo / Abstract: Compounds found in nature, show an enormous range of diversity in terms of structure and pharmacologic activities. Plants play a surprisingly important source of new treatments for cancer, despite advances in chemical synthesis. Thus the aim of this study was to evaluate six phytomedicine belonging to the class of lignoid (dimethoxymagnolol, grandisin and yangambin) and riparins (I, II and III) with and without glutathione supplementation (GSH ¿ 1mM) in three leukemic lines, K562, U937 and HL60. The cell viability was evaluated by MTT reduction assay in leukemic cells treated with the phytochemicals (with or without GSH supplementation). In the U937 cell IC50 values found were 100 µM, 30 µM and 500 µM in the cells treated with dimethoximagnolol, grandisin and yangambin, respectively and 60, 25 and 15 µM (riparin I, II and III, respectively). In K562 cells the treatment with riparins were the most effective class of compounds studied since it was determined IC50 values of 125, 27 and 15µM (riparin I, II and III, respectively). Different values were determined in the HL60 cells treated with riparins (140, 100 and 75 ?M for riparin I, II and III, respectively). GSH ameliorated only the toxic effects evaluated in U937 cell treated with riparin II, since it was not observed different results in the others cell lines treated with the studied compounds plus GSH. The cytotoxicity of phytochemicals was also assessed in a permanent lung fibroblast cell line (V79) culture that are cells commonly used for cytotoxicity studies. All the phytochemicals investigated, with the yangambin exception, were less cytotoxic to V79 cells than to leukemic cells. These results indicate a positive pharmacologic application since the leukemic activity was major than to the toxic effects evaluated in the V79 cells. All the compounds investigated in this work has antitumoral effects, however the action mechanism of riparin II is different on U937 cell since GSH supplementation protected the toxic effects. Probably, riparin II triggered cell death by stress oxidative pathway / Mestrado / Metabolismo e Biologia Molecular / Mestra em Ciências da Nutrição e do Esporte e Metabolismo