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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Effect of hydroxytyrosol supplementation on the lipid profile and metabolic disease risk markers in healthy men

Burns, James Dorsey 03 December 2013 (has links)
Hydroxytyrosol (HT) has been found to be a potent antioxidant and hypocholesterolemic agent in various animal models of disease including dyslipidemia, atherosclerosis, and diabetes. Therefore, the purpose of this study was to examine the effects of hydroxytyrosol (HT) supplementation on the lipid profile and metabolic risk markers in recreationally active men. Sixty-one (n = 61) subjects (21.46 ± 0.22 yrs, 179.46 ± 0.79 cm, 78.91 ± 1.19 kg) consumed HT in either a high dose (HI, 150 mg HT; n = 22), a low dose (LO, 50 mg HT; n = 20), or a placebo (PLA; n = 19) every day for 6 weeks. Blood draws were obtained at baseline, 14, 28, and 39 days under fasting conditions. Analyzed were the components of the plasma lipid profile: total cholesterol (TC), high density lipoprotein cholesterol (HDLc), the TC:HDLc fraction, low density lipoprotein cholesterol (LDLc), very low density lipoprotein cholesterol (VLDLc), and triglycerides (Tg); and markers of metabolic risk: uric acid, lipase, hemoglobin (Hb), glycated hemoglobin (HbA1c), and blood glucose (BG). The primary finding was that HT, in either HI or LO dosages did not cause clinically meaningful changes in the blood lipid profile or markers of metabolic risk. Subjects in the HI group experienced a small big significant increase in fasting blood glucose, while those in the PLA group experienced a significant increase in VLDLc concentration. In both cases, however, the mean values remained within their respective healthy reference ranges. Whether these changes would persist beyond the 6-week course of this study is not known. While no improvements were seen in any of our selected measures, these results indicate that HT supplementation, ranging from 50 to 150 mg/day, is safe to consume for durations up to 6 weeks in healthy young men. By maintaining the lipid profile and metabolic risk markers within a healthy range, it is possible that HT may impart a degree of protection against cardiovascular and metabolic disease risk, but such an effect may only be apparent when the plasma lipid and/or metabolic risk profile is abnormal. / text
2

Characterization of changes in lipid profile during development of the moss Physcomitrium patens

Gautam, Deepshila, Kilaru, Aruna 18 March 2021 (has links)
Lipids are the main constituents of the cell membrane and maintain its fluidity. Plants undergo various changes in lipids under environmental stresses and alter the membrane fluidity and permeability. Membrane lipids mostly contain a polar or neutral head group and fatty acid tails that vary in length and degree of unsaturation. The composition of membrane affects its physicochemical properties and ability to tolerate stress. The moss Physcomitrium patens is an early land plant with unique ability to tolerate stressors like cold and dehydration. During its life cycle, for the most part, mosses remain as gametophytes, multiplying asexually. The period from germination of spores into filamentous protonema, which give rise to gametophyte is transient. They enter reproductive sporophytes stage only under cold temperatures. Because of the diverse roles of these developmental stages and the time span they are exposed to the environment, we hypothesized that these stages share distinct lipid content and composition. To this extent, using LC-MS/MS methods we carried out lipidomic analyses of five developmental stages of the moss. We identified and quantified the major and minor lipid classes (types) and their acyl composition of protonema, early, mid and late gametophyte and sporophyte tissues. Galactolipids, which typically occur in the plastid were predominant in green tissues and thus most abundant in the vegetative tissues but not in sporophytes. Throughout the life cycle, among the phospholipids, phosphatidylcholine was the abundant lipid, a feature that is typical of plant membranes. Sporophyte tissues, however, were distinct from gametophyte and protonema and also other vascular plants with high amounts of phosphatidic acid (PA). In plants, PA typically accumulates in response to stress; it is likely that the low temperature cue necessary for sporophyte formation is associated with spike in PA and needs further investigation. In comparing the acyl composition of the various lipid classes, we identified that in addition to 34C and 36C lipids, moss lipids also contain 38C and 40C, which are not represented in vascular plants. We predict that the occurrence of long-chain, highly unsaturated lipids might contribute to the dynamic nature of the membrane and stability under stress. This study serves as a primary resource to further investigate the role of specific lipids and acyl groups in maintaining membrane properties. Overall, it aids to our understanding of the evolution of stress tolerance in early land plants that coped through harsh environmental conditions during their transition from water to land.
3

Avaliação da medida do colesterol total na determinação do risco lipídico para doença arterial coronária / Evaluation of total cholesterol measurement in the determination of lipid risk for coronary artery disease

Bertolami, Marcelo Chiara 16 September 1996 (has links)
Foram estudadas, quanto ao perfil lipídico, duas populações, compreendendo indivíduos acima dos 20 anos de idade: -trabalhadores da Termomecânica, indústria metalúrgica de São Bernardo do Campo: 1.616 do sexo masculino e 230 do sexo feminino; -pacientes atendidos no ambulatório do Hospital das Clínicas da Universidade Estadual de Campinas (UNICAMP): 664 do sexo feminino e 317 do sexo masculino. Os objetivos foram: I. Avaliar se a determinação isolada da colesterolemia total, sem considerar a dos triglicérides e a do HDL-colesterol e o cálculo do LDL-colesterol pela fórmula de Friedewald, para rastreamento populacional ou para decisão de tratamento, implica importante porcentagem de aparecimento de casos classificados inadequadamente, considerando o LDL-colesterol como \"padrão ouro\". 2. Analisar se a determinação da trigliceridemia associada à da colesterolemia total, além de mostrar os casos que apresentam hipertrigliceridemia isolada, auxilia a melhor identificação dos casos quanto ao LDL-colesterol. 3. Avaliar, com base na determinação isolada da colesterolemia total, qual a chance de os pacientes, por não lerem seu HDL-colesterol dosado, estar em maior risco lipídico para doença ateroselerótica por apresentar essa fração do colesterol abaixo do desejável. As conclusões foram: I. A dosagem isolada do colesterol total pode levar a chance importante de classificar enganosamente um paciente (em relação ao LDL-colesterol calculado). Para o rastreamento, os falsos negativos variaram de 9 por cento a 24 por cento e os falsos positivos, de 10 por cento a 24 por cento. Para a situação de decisão de tratamento, a variação dos falsos negativos foi de 14 por cento a 25 por cento, enquanto a dos falsos positivos foi de 1 por cento a 9 por cento. 2. A determinação dos triglicérides associada à do colesterol total auxilia a melhor identificação dos casos que apresentam LDL-colesterol elevado, somente quando a colesterolemia se encontra abaixo ue 240 mg/dl. Para níveis de colesterol totai iguais ou acima desse valor, a determinação também dos triglicérides não auxilia a melhor identificação do risco lipídico pelo LDL-colesterol ou a necessidade de tratamento dessa variável do perfil lipídico. A não possibilidade do diagnóstico de hipertrigliceridemia isolada (acima de 200 mg/dl) quando da determinação somente do colesterol total apresentou baixas chances nas populações avaliadas neste estudo, de 0,5 por cento a 3 por cento. 3. A não determinação do HDL-colesterol associa risco de erro pequeno de não identificação de paciente com risco de doença coronária por nível baixo dessa fração do colesterol (abaixo de 35 mg/dl), com colesterol total em níveis desejáveis (abaixo de 200 mg/dl), que variou de 3 por cento a 10 por cento. / Lipid profile of two populations composed of individuais older than 20 years, was studied: - metallurgic employees from São Bernardo do Campo (Termomecânica): 1,616 males and 230 females; - outpatients seen in the Hospital das Clínicas from Campinas State University (UNICAMP): 664 females and 317 males. The objectives were: I. To evaluate if the isolated determination of serum total cholesterol, without triglyceridcs, HDL-cholesterol and calculation of LDL-cholesterol by Friedewald\'s formula, for population screening or treatement decision implicates in high percentage of misclassification, considering LDL-cholesterol as the gold standard. 2. To analyze if triglycerides associated to total cholesterol determination helps in better identification of cases according to LDL-cholesterol, parallel to the definition of the percentage of cases presenting isolated hypertriglyceridemia. 3. To evaluate what is the chance of, according to isolated total choleslerol determination, patients being misclassified due a low HDL-cholesterol. The conclusions were: I. Isolated determination of total cholesterol can induce to an important chance of misclassifying a patient (according to calculated LDL-cholesterol). For screening, false negatives ranged from 9 per cent to 24 per cent and false positives from 10 per cent to 24 per cent. For treatment decision situation, false negatives varied from 14 per cent to 25 per cent, while false positives varied from 1 per cent to 9 per cent. 2. Triglycerides determination associated to total cholesterol helps in better identification of cases presenting elevated LDL-cholesterol, only when the cholesterolemia is below 240 mg/dL. For total cholesterol equal or above this value, triglycerides determination does not improve better identification of lipid risk depending on LDL-cholesterol during screening or treatment imposition. The impossibility of diagnosing isolated hypertriglyeeridemia (above 200 mg/dL) when only total cholesterol determination is done present low chance in both studied populations varying from 0.5 per cent to 3 per cent. 3. In a patient presenting a desirable total cholesterol level (below 200 mg/dL), not dosing HDL-cholesterol associates low risk of misclassification depending on a low level or this lipoprotein fraction (below 35 mg/dL): from 3 per cent to 10 per cent.
4

Bioprospecting for extremophile oleaginous yeasts

Abd Ghaffar, Nur Rinah January 2017 (has links)
Palm Oil is the highest produced edible oil globally, with over 66 million tonnes produced annually. It has been estimated that up to 50% of all products sold in the supermarket contain palm oil in some form. Palm oil has attractive properties such as a high melting point and texture due to a balanced ratio of unsaturated and saturated fatty acids. It contains approximately 40% oleic acid (monounsaturated fatty acid), 10% linoleic acid (polyunsaturated fatty acid), 45% palmitic acid and 5% stearic acid (saturated fatty acid), that results in an edible oil that is suitable for use in a variety of food, detergent and cosmetics products. In addition, palm oil is the least expensive oil produced due to its high productivity and extensive production. Due to the high demand for the product, vast amounts of rainforest have been cleared to make way for more plantations, reducing biodiversity and releasing huge levels of carbon dioxide into the atmosphere. There is a clear need for an alternative lipid that can match palm oils properties but can be produced sustainably. Recent work suggests that some yeasts are capable of producing a similar oil to palm oil and can be grown on waste resources. In this thesis a novel bioprospecting protocol was developed to isolate yeasts that can survive the harsh conditions necessary for industrial biotechnology. In this way a vineyard and the local area was sampled for yeasts which were then cultured under extremes of pH, multiple sugars and inhibitors caused from the breakdown of lignocellulose. The wild yeast were cultured in four stages: minimal medium with Lysine; minimal medium with inhibitors; minimal medium with xylose as sole carbon-source; and lastly minimal medium with only arabinose and cellobiose as carbon-sources. Only strains that survived each stage were taken forward to the next, to isolate species that were truly suited to these conditions. Out of the estimated 1000s of strains screened this resulted in 12 strains of yeast, mostly in the Metschnikowia pulcherrima, group being able to cope with the conditions. The 12 strains were further analyzed by culturing them in an array of 4 different model lignocellulosic feedstocks namely wheat straw, corn Stover, sugarcane bagasse, and palm kernel cake hydrolysates. Other conditions incorporated in these analysis were a range of pH from pH 1.5 to pH 7.0; four levels of a mixture of 5 inhibitors; and two different temperatures. All of the 12 strains showed similar behaviour where inhibitor tolerance was only marked at higher pH, and at low pH the strains could not grow at all. Though all strains were able to grow on the hydrolysate models, even those with little glucose and/or xylose content. The lipid profile of the strains was also assessed and proved to be similar to most terrestrial crops, with suitable lipid profiles for a rapeseed oil, and in some cases palm oil substitute. Lastly, to further evaluate the accurate identification of the strains as there are some ambiguity in the Metschnikowia pulcherrima group, we applied an approach only widely used for Pathogenic Bacteria/Yeast identification, Multilocus Sequence Typing (MLST). Using 25 strains (7 of this collection), 6 type species and some isolates from the original culture collection in Bath. Sequences of 6 genes was analysed using the Bayesian statistical method. The result showed grouping of M. pulcherrima into 3-4 groups 9 different for each gene. M. Corniflorae being the outgroup. In all 3 genes successfully sequenced: M. Fruticola; R6; Mp DAH 3; and ICS48 were consistently shown to be clonal. The work presented here demonstrates a new method for bioprospecting strains capable of isolating strains for industrial biotechnology, and for characterisation of the yeast in the Metschnikowia genus. Some of the yeasts identified were oleaginous, and could potentially be used as a novel source of palm oil substitute.
5

Avaliação da medida do colesterol total na determinação do risco lipídico para doença arterial coronária / Evaluation of total cholesterol measurement in the determination of lipid risk for coronary artery disease

Marcelo Chiara Bertolami 16 September 1996 (has links)
Foram estudadas, quanto ao perfil lipídico, duas populações, compreendendo indivíduos acima dos 20 anos de idade: -trabalhadores da Termomecânica, indústria metalúrgica de São Bernardo do Campo: 1.616 do sexo masculino e 230 do sexo feminino; -pacientes atendidos no ambulatório do Hospital das Clínicas da Universidade Estadual de Campinas (UNICAMP): 664 do sexo feminino e 317 do sexo masculino. Os objetivos foram: I. Avaliar se a determinação isolada da colesterolemia total, sem considerar a dos triglicérides e a do HDL-colesterol e o cálculo do LDL-colesterol pela fórmula de Friedewald, para rastreamento populacional ou para decisão de tratamento, implica importante porcentagem de aparecimento de casos classificados inadequadamente, considerando o LDL-colesterol como \"padrão ouro\". 2. Analisar se a determinação da trigliceridemia associada à da colesterolemia total, além de mostrar os casos que apresentam hipertrigliceridemia isolada, auxilia a melhor identificação dos casos quanto ao LDL-colesterol. 3. Avaliar, com base na determinação isolada da colesterolemia total, qual a chance de os pacientes, por não lerem seu HDL-colesterol dosado, estar em maior risco lipídico para doença ateroselerótica por apresentar essa fração do colesterol abaixo do desejável. As conclusões foram: I. A dosagem isolada do colesterol total pode levar a chance importante de classificar enganosamente um paciente (em relação ao LDL-colesterol calculado). Para o rastreamento, os falsos negativos variaram de 9 por cento a 24 por cento e os falsos positivos, de 10 por cento a 24 por cento. Para a situação de decisão de tratamento, a variação dos falsos negativos foi de 14 por cento a 25 por cento, enquanto a dos falsos positivos foi de 1 por cento a 9 por cento. 2. A determinação dos triglicérides associada à do colesterol total auxilia a melhor identificação dos casos que apresentam LDL-colesterol elevado, somente quando a colesterolemia se encontra abaixo ue 240 mg/dl. Para níveis de colesterol totai iguais ou acima desse valor, a determinação também dos triglicérides não auxilia a melhor identificação do risco lipídico pelo LDL-colesterol ou a necessidade de tratamento dessa variável do perfil lipídico. A não possibilidade do diagnóstico de hipertrigliceridemia isolada (acima de 200 mg/dl) quando da determinação somente do colesterol total apresentou baixas chances nas populações avaliadas neste estudo, de 0,5 por cento a 3 por cento. 3. A não determinação do HDL-colesterol associa risco de erro pequeno de não identificação de paciente com risco de doença coronária por nível baixo dessa fração do colesterol (abaixo de 35 mg/dl), com colesterol total em níveis desejáveis (abaixo de 200 mg/dl), que variou de 3 por cento a 10 por cento. / Lipid profile of two populations composed of individuais older than 20 years, was studied: - metallurgic employees from São Bernardo do Campo (Termomecânica): 1,616 males and 230 females; - outpatients seen in the Hospital das Clínicas from Campinas State University (UNICAMP): 664 females and 317 males. The objectives were: I. To evaluate if the isolated determination of serum total cholesterol, without triglyceridcs, HDL-cholesterol and calculation of LDL-cholesterol by Friedewald\'s formula, for population screening or treatement decision implicates in high percentage of misclassification, considering LDL-cholesterol as the gold standard. 2. To analyze if triglycerides associated to total cholesterol determination helps in better identification of cases according to LDL-cholesterol, parallel to the definition of the percentage of cases presenting isolated hypertriglyceridemia. 3. To evaluate what is the chance of, according to isolated total choleslerol determination, patients being misclassified due a low HDL-cholesterol. The conclusions were: I. Isolated determination of total cholesterol can induce to an important chance of misclassifying a patient (according to calculated LDL-cholesterol). For screening, false negatives ranged from 9 per cent to 24 per cent and false positives from 10 per cent to 24 per cent. For treatment decision situation, false negatives varied from 14 per cent to 25 per cent, while false positives varied from 1 per cent to 9 per cent. 2. Triglycerides determination associated to total cholesterol helps in better identification of cases presenting elevated LDL-cholesterol, only when the cholesterolemia is below 240 mg/dL. For total cholesterol equal or above this value, triglycerides determination does not improve better identification of lipid risk depending on LDL-cholesterol during screening or treatment imposition. The impossibility of diagnosing isolated hypertriglyeeridemia (above 200 mg/dL) when only total cholesterol determination is done present low chance in both studied populations varying from 0.5 per cent to 3 per cent. 3. In a patient presenting a desirable total cholesterol level (below 200 mg/dL), not dosing HDL-cholesterol associates low risk of misclassification depending on a low level or this lipoprotein fraction (below 35 mg/dL): from 3 per cent to 10 per cent.
6

The Modulating Effect of Fatty Acids on the Lipid Profile in Colon Epithelial Mucosa In Vivo.

Abrahams, Celeste H. January 2009 (has links)
<p>Several abnormal conditions, including some cancers, have been associated with changes in the membrane lipid and FA composition. Dietary fat serves as a major source of lipids and FA, particularly the polyunsaturated fatty acids (PUFA), n-6 and n-3. High intakes of n-6 PUFA have been linked to the development of colon cancer in association with low n-3 PUFA intake. Therefore understanding the differences in the lipid and FA profiles between cancer and normal cells in the colon, and the role diet plays in these factors may be invaluable in understanding their role in carcinogenesis. This study compares the lipid profile of azoxymethane (AOM) induced colon polyps to that of the surrounding mucosa tissue in rats fed a diet high in n-6 PUFA. Male Fischer rats were fed the AIN-76A diet containing sunflower oil that has high n-6 PUFA content for a period of nine months. Results indicate that the lipid and FA content of the colon polyps differs significantly from the surrounding mucosa. Colon polyps had an increase in membrane phopholipids phosphatidylcholine (PC) and phosphatidylethanolamine (PE). Changes in membrane fluidity were indicated by the decrease (p&lt / 0.05) in the PC/PE and cholesterol/phospholipids (chol/PL) ratios, and increase (p&lt / 0.05) in the polyunsaturated FA/saturated FA (P/S) ratio. Metabolism of FA was significantly altered in the polyps favouring n-6 FA metabolism and the production of prostaglandin E2. No clear indication of impaired &Delta / 6-desauturase enzyme activity was noticed. Increases in the n-6 PUFA content could be a reflection of the dietary FA intake that increases FA incorporation in the polyps. Changes in the FA parameters of the polyps, particularly an increase in C20:4n-6 and the n6/n3 ratio have been shown to contribute to the rapid growth of cancer tissue. These lipid changes associated with the development of colon polyps could provide unique targets for developing strategies in chemoprevention by dietary manipulation.</p>
7

The Modulating Effect of Fatty Acids on the Lipid Profile in Colon Epithelial Mucosa In Vivo.

Abrahams, Celeste H. January 2009 (has links)
<p>Several abnormal conditions, including some cancers, have been associated with changes in the membrane lipid and FA composition. Dietary fat serves as a major source of lipids and FA, particularly the polyunsaturated fatty acids (PUFA), n-6 and n-3. High intakes of n-6 PUFA have been linked to the development of colon cancer in association with low n-3 PUFA intake. Therefore understanding the differences in the lipid and FA profiles between cancer and normal cells in the colon, and the role diet plays in these factors may be invaluable in understanding their role in carcinogenesis. This study compares the lipid profile of azoxymethane (AOM) induced colon polyps to that of the surrounding mucosa tissue in rats fed a diet high in n-6 PUFA. Male Fischer rats were fed the AIN-76A diet containing sunflower oil that has high n-6 PUFA content for a period of nine months. Results indicate that the lipid and FA content of the colon polyps differs significantly from the surrounding mucosa. Colon polyps had an increase in membrane phopholipids phosphatidylcholine (PC) and phosphatidylethanolamine (PE). Changes in membrane fluidity were indicated by the decrease (p&lt / 0.05) in the PC/PE and cholesterol/phospholipids (chol/PL) ratios, and increase (p&lt / 0.05) in the polyunsaturated FA/saturated FA (P/S) ratio. Metabolism of FA was significantly altered in the polyps favouring n-6 FA metabolism and the production of prostaglandin E2. No clear indication of impaired &Delta / 6-desauturase enzyme activity was noticed. Increases in the n-6 PUFA content could be a reflection of the dietary FA intake that increases FA incorporation in the polyps. Changes in the FA parameters of the polyps, particularly an increase in C20:4n-6 and the n6/n3 ratio have been shown to contribute to the rapid growth of cancer tissue. These lipid changes associated with the development of colon polyps could provide unique targets for developing strategies in chemoprevention by dietary manipulation.</p>
8

Dosage ranging effect and safety evaluation of conjugated linoleic acid (CLA) in a hamster model

Liu, Xiaoran 09 September 2010 (has links)
The objectives of this study was to examine the efficacy and safety of graded doses of c9, t11, t10, c12 CLA isomers on body composition, energy expenditure, lipid profile and hepatic biomarkers in hamsters. Male Golden Syrian hamsters (n=105) were randomized to seven treatments (control; 1, 2, 3% of c9, t11; 1, 2, 3% of t10, c12) for 28 days. Compared with control, 1% and 3% t10, c12 had lowered food intake with all three doses of t10, c12 lowering (p<0.0001) body fat mass (g). Groups fed with 1, 2, 3% t10, c12 and 3% c9, t11 treatments showed higher lean mass compared to control and other treatment groups. However, neither body weights, nor serum HDL or triglyceride levels differed across treatment groups. The 3% t10, c12 groups exhibited higher (p<0.0001) cholesterol and LDL-C levels compared to control or other treatment groups. The 2% and 3% t10, c12 groups also presented elevated ALT level (p<0.05). The present data suggest that 3% t10, c12 possess potential adverse effects on liver and posing unfavorable change in lipid profile.
9

Dosage ranging effect and safety evaluation of conjugated linoleic acid (CLA) in a hamster model

Liu, Xiaoran 09 September 2010 (has links)
The objectives of this study was to examine the efficacy and safety of graded doses of c9, t11, t10, c12 CLA isomers on body composition, energy expenditure, lipid profile and hepatic biomarkers in hamsters. Male Golden Syrian hamsters (n=105) were randomized to seven treatments (control; 1, 2, 3% of c9, t11; 1, 2, 3% of t10, c12) for 28 days. Compared with control, 1% and 3% t10, c12 had lowered food intake with all three doses of t10, c12 lowering (p<0.0001) body fat mass (g). Groups fed with 1, 2, 3% t10, c12 and 3% c9, t11 treatments showed higher lean mass compared to control and other treatment groups. However, neither body weights, nor serum HDL or triglyceride levels differed across treatment groups. The 3% t10, c12 groups exhibited higher (p<0.0001) cholesterol and LDL-C levels compared to control or other treatment groups. The 2% and 3% t10, c12 groups also presented elevated ALT level (p<0.05). The present data suggest that 3% t10, c12 possess potential adverse effects on liver and posing unfavorable change in lipid profile.
10

The modulating effect of fatty acids on the lipid profile in colon epithelial mucosa in Vivo

Abrahams, Celeste H. January 2009 (has links)
Magister Scientiae - MSc / Several abnormal conditions, including some cancers, have been associated with changes in the membrane lipid and FA composition. Dietary fat serves as a major source of lipids and FA, particularly the polyunsaturated fatty acids (PUFA), n-6 and n-3. High intakes of n-6 PUFA have been linked to the development of colon cancer in association with low n-3 PUFA intake. Therefore understanding the differences in the lipid and FA profiles between cancer and normal cells in the colon, and the role diet plays in these factors may be invaluable in understanding their role in carcinogenesis. This study compares the lipid profile of azoxymethane (AOM) induced colon polyps to that of the surrounding mucosa tissue in rats fed a diet high in n-6 PUFA. Male Fischer rats were fed the AIN-76A diet containing sunflower oil that has high n-6 PUFA content for a period of nine months. Results indicate that the lipid and FA content of the colon polyps differs significantly from the surrounding mucosa. Colon polyps had an increase in membrane phopholipids phosphatidylcholine (PC) and phosphatidylethanolamine (PE). Changes in membrane fluidity were indicated by the decrease (0.05) in the PC/PE and cholesterol/phospholipids (chol/PL) ratios, and increase (0.05) in the polyunsaturated FA/saturated FA (P/S) ratio. Metabolism of FA was significantly altered in the polyps favouring n-6 FA metabolism and the production of prostaglandin E2. No clear indication of impaired & Delta;6-desauturase enzyme activity was noticed. Increases in the n-6 PUFA content could be a reflection of the dietary FA intake that increases FA incorporation in the polyps. Changes in the FA parameters of the polyps, particularly an increase in C20:4n-6 and the n6/n3 ratio have been shown to contribute to the rapid growth of cancer tissue. These lipid changes associated with the development of colon polyps could provide unique targets for developing strategies in chemoprevention by dietary manipulation. / South Africa

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