Structured phospholipids with conjugated linolenic acid were produced for potential applications in nutraceuticals and functional foods. Structured phospholipids were synthesized with conjugated linolenic acid (CLnA) from natural sources by catalytic enzymatic reaction. Pomegranate seed oil, as a natural source of CLnA, and an isomerized-concentrated mixture (ICM) of CLnA from flaxseed oil were used for the enzymatic reaction with phosphotidylcholine (PC) using Liposyme TL IM for fatty acid modification at 57 °C for 96 h. The enzymatic process was an effective way to produce structured phospholipids with CLnA. The maximum incorporation of CLnA from pomegranate seed oil and ICM from flaxseed oil into PC was 11.3% and 4.9% after 72 h, respectively. Structured lysophospholipids were also obtained as a result of the enzymatic reaction. The maximum incorporation of CLnA from pomegranate oil and ICM from flaxseed oil into lysophospholipids was 17.2% and 13.5% after 72h, respectively. Physical properties such as dropping point and viscosity at 40 and 50 °C of the structured phospholipids produced were measured when they were added to a chocolate mixture (unsweetened chocolate 94.6%, coconut oil 5% and 0.4 % phospholipids). Two controls were used for comparison: the chocolate mixture without phospholipids and the chocolate mixture with Lipoid S100 (phosphatidylcholine 94%). Structured phospholipids with CLnA showed lower dropping point and viscosities than the controls. Oil-in-water emulsions were prepared with whey protein (1%), soy bean oil (10%) and phospholipids (0.5%) in a high pressure homogenizer at 20MPa. The emulsion stability of the emulsions prepared, control (without phospholipids), Lipoid S 100 and structured phospholipids with CLnA were determined by visual observation of phase separation. The structured phospholipids emulsion showed higher emulsion stability than the controls. This emulsion was stable up to 108 h while the emulsion without phospholipid and Lipoid S100 were 48 h and 96 h stable, respectively. Oxidative stability of the emulsions prepared was determined by measuring the peroxide value and p-anisidine value after 1, 3 and 7 days at 50 °C. Oil was extracted from the emulsions using isooctane:isopropanol (3:2 v/v). The structured phospholipid emulsions showed lower oxidative stability than the controls.

Structured phospholipids with conjugated linolenic acid were produced for potential applications in nutraceuticals and functional foods. Structured phospholipids were synthesized with conjugated linolenic acid (CLnA) from natural sources by catalytic enzymatic reaction. Pomegranate seed oil, as a natural source of CLnA, and an isomerized-concentrated mixture (ICM) of CLnA from flaxseed oil were used for the enzymatic reaction with phosphotidylcholine (PC) using Liposyme TL IM for fatty acid modification at 57 °C for 96 h. The enzymatic process was an effective way to produce structured phospholipids with CLnA. The maximum incorporation of CLnA from pomegranate seed oil and ICM from flaxseed oil into PC was 11.3% and 4.9% after 72 h, respectively. Structured lysophospholipids were also obtained as a result of the enzymatic reaction. The maximum incorporation of CLnA from pomegranate oil and ICM from flaxseed oil into lysophospholipids was 17.2% and 13.5% after 72h, respectively. Physical properties such as dropping point and viscosity at 40 and 50 °C of the structured phospholipids produced were measured when they were added to a chocolate mixture (unsweetened chocolate 94.6%, coconut oil 5% and 0.4 % phospholipids). Two controls were used for comparison: the chocolate mixture without phospholipids and the chocolate mixture with Lipoid S100 (phosphatidylcholine 94%). Structured phospholipids with CLnA showed lower dropping point and viscosities than the controls. Oil-in-water emulsions were prepared with whey protein (1%), soy bean oil (10%) and phospholipids (0.5%) in a high pressure homogenizer at 20MPa. The emulsion stability of the emulsions prepared, control (without phospholipids), Lipoid S 100 and structured phospholipids with CLnA were determined by visual observation of phase separation. The structured phospholipids emulsion showed higher emulsion stability than the controls. This emulsion was stable up to 108 h while the emulsion without phospholipid and Lipoid S100 were 48 h and 96 h stable, respectively. Oxidative stability of the emulsions prepared was determined by measuring the peroxide value and p-anisidine value after 1, 3 and 7 days at 50 °C. Oil was extracted from the emulsions using isooctane:isopropanol (3:2 v/v). The structured phospholipid emulsions showed lower oxidative stability than the controls.

Thesis (Ph. D.)--University of Alberta, 2010. / Title from pdf file main screen (viewed on Feb. 8, 2010). A thesis submitted to the Faculty of Graduate Studies and Research in partial fulfillment of the requirements for the degree of Doctor of Philosophy in Animal Science, Department of Agricultural, Food and Nutritional Science, University of Alberta. Includes bibliographical references.

This study utilizes steady state fluorescence measurements, flash-induced P680+ absorption transients, and DCIP reduction kinetics to study the inhibitory effects of linolenic acid (LA) upon Photosystem II (PSII) in whole spinach chloroplasts and insideout wheat thylakoids. It confirms the presence within PSII of LA-induced inhibition of energy trapping and/or primary charge separation (i.e., primary inhibition), in addition to donor side inhibition. The latter is diminished in the presence of 1,5-Diphenylcarbohydrazide (DPC) and probably takes place at the oxygen evolving complex. Primary inhibition, which is more controversial, probably occurs between Ph and QA, with a likely contribution at the level of PSII energy trapping. In addition, the ability of Mg2+ to delay a drop in steady state fluorescence intensity normally associated with thylakoid exposure to LA is explained by the ability of this cation to confer resistance to LA-induced destacking of thylakoid membranes. Steady state fluorescence results in the presence of DCMU, dithionite and LA also support the presence of an additional acceptor between Ph and QA. This acceptor, designated here as "R." is proposed not to be a sequential member of the transport chain, but may be accessible to it via QA when the chain blocked, such as with DCMU.R- is proposed to exert a coulombic effect upon Ph, thereby affecting the degree of primary charge recombination. It may be related to one of the several acceptors already proposed by others and the need for more study is stressed in order to confirm or refute its existence.

Chronic, low-grade inflammation is a contributing factor in diseases that impact the health and well-being of horses. Pharmaceutical treatments reduce inflammation, but their use results in negative digestive and kidney disturbances. Polyunsaturated fatty acids (PUFA) play a role in mitigating the inflammatory response and are therefore explored as a dietary approach to attenuate inflammation. γ-Linolenic acid (GLA) is a unique PUFA that when supplemented in the diet can increase the production of anti-inflammatory eicosanoids; however, it is uncommon in the dietary components normally fed to horses. Interest in industrial hemp (Cannabis sativa L.) as a novel source of PUFA stems from the presence of GLA and the potential to reduce inflammation; although, concerns over cannabinoid contamination limit its acceptance. Six Thoroughbred geldings were used in a crossover study with two 63-d periods to measure PUFA metabolism, inflammatory biomarkers, and cannabinoid accumulation in response to hempseed oil (HSO) fed to sedentary horses compared to controls (CON). Treatment diets were offered for the first 35 d of each period and then all horses resumed a uniform feeding rate from d 36 to 63. Serum and synovial fluid PUFA reflected dietary intake. GLA was greater in serum (0.465 vs. 0.046; P < 0.0001) and synovial fluid (0.270 vs. 0; P < 0.0001) in horses fed HSO compared to CON. This contributed to greater dihomo-γ-linolenic acid (DGLA) conversion in serum (0.287 vs. 0.195; P < 0.0001) and synovial fluid (0.348 vs. 0.262; P < 0.04) but not arachidonic acid (AA). Serum GLA returned to baseline concentrations by two weeks post-supplementation, but no treatment x time effect was observed for synovial fluid. HSO did not affect FA in muscle; it is likely the length or quantity of supplementation was inadequate to see changes in muscle PUFA. HSO increased serum interleukin 1β (IL1β; P = 0.01) but there was no treatment by time interaction (P = 0.62). No other inflammatory biomarkers were influenced by treatment. Stride length was not affected by HSO supplementation but was inversely correlated (P ≤ 0.01) with synovial fluid prostaglandin E2 (PGE2; r = -0.56), and positively correlated with serum tumor necrosis factor α (TNFα; r = 0.58), serum IL6 (r = 0.61), and serum IL1β (r = 0.65). Cannabinoids were measured in the HSO supplement, but no cannabinoids were detected in plasma or synovial fluid of horses fed HSO when tested to a 50-ppb limit of detection. These results demonstrate the suitability of HSO as a novel source of PUFA and, more specifically, as a source of GLA without further increasing AA, however, implications for its effect on inflammation require further evaluation. / Doctor of Philosophy / Inflammation contributes to diseases in the horses that reduce their health and well-being. Anti-inflammatory drugs reduce inflammation but are associated with negative health effects including gastric ulcer formation and kidney damage. Diet can influence the inflammatory response and is therefore targeted to moderate inflammation. Specific dietary targets include polyunsaturated fatty acids (PUFA). Hempseed (Cannabis sativa L.) oil (HSO) contains a unique and uncommon dietary PUFA, γ-Linolenic acid (GLA), which can increase the production of anti-inflammatory biomolecules. The goal of this research was to measure PUFA accumulation, specifically GLA, in horses fed HSO for 35 d and then clearance for 28 d post-supplementation. Additionally, we looked at inflammatory markers to determine the effect on inflammation in sedentary horses. Finally, we measured cannabinoids to evaluate if the low level of cannabinoid contamination found in HSO transfers to horse plasma and synovial fluid. To accomplish these goals, we conducted a feeding trial from May 2022 to September 2022 using six Thoroughbred geldings in a cross over study with two 63 d periods. HSO was supplemented the first 35 d of each period and then removed. Serum and synovial fluid PUFA reflected dietary PUFA. Inflammatory biomarkers had a mixed response that could be influenced by additional, unknown factors. The low-level of cannabinoids in the HSO supplement were not detected in plasma or synovial fluid. HSO shows promise as a novel source of PUFA, specifically GLA, without concerns of cannabinoid contaminants.

Lam, Cheuk Kai. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2007. / Includes bibliographical references (leaves 148-173). / Abstracts in English and Chinese. / ACKNOWLEDGEMENTS --- p.i / ABSTRACT --- p.ii / LIST OF ABBREVIATIONS --- p.vi / TABLE OF CONTENTS --- p.x / Chapter CHAPTER 1 --- GENERAL INTRODUCTION / Chapter 1.1 --- Introduction to Cholesterol and Its Related Diseases --- p.1 / Chapter 1.1.1 --- Chemistry of cholesterol --- p.1 / Chapter 1.1.2 --- Physiological importance of cholesterol --- p.1 / Chapter 1.1.3 --- Pathological effects of cholesterol --- p.3 / Chapter 1.1.3.1 --- Mechanism of atherosclerosis --- p.3 / Chapter 1.2 --- Cholesterol Homeostasis --- p.6 / Chapter 1.2.1 --- Liver as the main organ for cholesterol metabolism --- p.6 / Chapter 1.2.2 --- Regulatory sites of cholesterol metabolism --- p.6 / Chapter 1.2.2.1 --- Regulation of cholesterol absorption by acyl coenzyme A: cholesterol acyltransferase (ACAT) --- p.6 / Chapter 1.2.2.2 --- Sterol regulatory element-binding protein 2 (SREBP-2) as a transcription factor for 3 -hydroxy-3 -methylglutaryl coenzyme A reductase (HMGR) and low-density lipoprotein receptor (LDLR) --- p.10 / Chapter 1.2.2.3 --- Roles ofLDLR --- p.11 / Chapter 1.2.2.4 --- Rate limiting role of HMGR in cholesterol de novo synthesis --- p.14 / Chapter 1.2.2.5 --- Roles of liver-X-receptor-a (LXR-a) in cholesterol catabolism --- p.16 / Chapter 1.2.2.6 --- Roles of CYP7A1 in catabolism of cholesterol into bile acids --- p.19 / Chapter 1.2.2.7 --- Roles of cholesterol ester transfer protein (CETP) in maintaining cholesterol distribution in blood --- p.22 / Chapter CHAPTER 2 --- EFFECT OF OCTADECAENOIC ACIDS ON BLOOD CHOLESTEROL IN HAMSTERS / Chapter 2.1 --- Introduction --- p.25 / Chapter 2.1.1 --- Effects of polyunsaturated fatty acids (PUFAs) on blood cholesterol --- p.25 / Chapter 2.1.2 --- Differential effects of 18-C PUFAs on lowering blood cholesterol in vivo --- p.25 / Chapter 2.1.3 --- "Structures, metabolism and conjugation of octadecaenoic acids (ODA)" --- p.26 / Chapter 2.1.4 --- Objectives --- p.26 / Chapter 2.2 --- Experiment 1 --- p.28 / Chapter 2.2.1 --- Materials and methods --- p.28 / Chapter 2.2.1.1 --- Experimental fatty acids --- p.28 / Chapter 2.2.1.1.1 --- Isolation of LN from flaxseed --- p.28 / Chapter 2.2.1.1.2 --- Isolation of CLN from tung seed --- p.28 / Chapter 2.2.1.2 --- Animals --- p.29 / Chapter 2.2.1.3 --- Diets --- p.30 / Chapter 2.2.1.4 --- Plasma lipid measurements --- p.30 / Chapter 2.2.1.5 --- Plasma CETP activity measurement --- p.30 / Chapter 2.2.1.6 --- "Measurement of liver SREBP-2, LDLR, HMGR and CYP7A1 protein abundance by Western blotting" --- p.34 / Chapter 2.2.1.7 --- "Measurement of hepatic SREBP-2, LDLR, HMGR, LXR, CYP7A1, CETP, SR-B1 and LCAT mRNA by real time PCR" --- p.35 / Chapter 2.2.1.7.1 --- Extraction of mRNA --- p.35 / Chapter 2.2.1.1.2 --- Complementary DNA synthesis --- p.36 / Chapter 2.2.1.7.3 --- Real-time polymerase chain reaction (PCR) anaylsis --- p.36 / Chapter 2.2.1.8 --- Determination of cholesterol in liver --- p.37 / Chapter 2.2.1.9 --- Determination of fecal neutral and acidic sterols --- p.38 / Chapter 2.2.1.9.1 --- Determination of fecal neutral sterols --- p.39 / Chapter 2.2.1.9.2 --- Determination of fecal acidic sterols --- p.41 / Chapter 2.2.1.10 --- Statistics --- p.43 / Chapter 2.2.2 --- Results --- p.44 / Chapter 2.2.2.1 --- Growth and food intake --- p.44 / Chapter 2.2.2.2 --- Organ weights --- p.44 / Chapter 2.2.2.3 --- "Effects of ODA on serum TC, TG and HDL-C" --- p.44 / Chapter 2.2.2.4 --- Effect of ODA on liver cholesterol --- p.48 / Chapter 2.2.2.5 --- Effect of ODA on fecal neutral sterol output --- p.48 / Chapter 2.2.2.6 --- Effect of ODA on fecal acidic sterol output --- p.48 / Chapter 2.2.2.7 --- Effect of ODA on cholesterol balance in hamsters --- p.52 / Chapter 2.2.2.8 --- Effect of ODA on plasma CETP activity --- p.52 / Chapter 2.2.2.9 --- Correlation between blood TC and liver cholesterol --- p.52 / Chapter 2.2.2.10 --- Correlation between blood HDL-C and liver cholesterol --- p.52 / Chapter 2.2.2.11 --- Correlation between blood nHDL/HDL ratio and liver cholesterol --- p.52 / Chapter 2.2.2.12 --- Effect ofODA on liver SREBP-2 immunoreactive mass --- p.58 / Chapter 2.2.2.13 --- Effect of ODA on liver LDLR immunoreactive mass --- p.58 / Chapter 2.2.2.14 --- Effect of ODA on liver HMGR immunoreactive mass --- p.58 / Chapter 2.2.2.15 --- Effect of ODA on liver LXR immunoreactive mass --- p.58 / Chapter 2.2.2.16 --- Effect of ODA on liver CYP7A1 immunoreactive mass --- p.63 / Chapter 2.2.2.17 --- Effects ofODA on hepatic CETP mRNA --- p.65 / Chapter 2.2.2.18 --- Effects of ODA on hepatic LDLR mRNA --- p.65 / Chapter 2.2.2.19 --- Effects of ODA on hepatic LXR mRNA --- p.65 / Chapter 2.2.2.20 --- Effects of ODA on hepatic CYP7A1 mRNA --- p.65 / Chapter 2.3 --- Experiment 2 --- p.70 / Chapter 2.3.1 --- Materials and Methods --- p.70 / Chapter 2.3.1.1 --- Experimental diets --- p.70 / Chapter 2.3.1.2 --- Animals --- p.70 / Chapter 2.3.1.3 --- Intestinal acyl coenzyme A: cholesterol acyltransferase (ACAT) activity measurement --- p.70 / Chapter 2.3.1.3.1 --- Preparation of intestinal microsome --- p.71 / Chapter 2.3.1.3.2 --- ACAT activity assay --- p.71 / Chapter 2.3.2 --- Results --- p.73 / Chapter 2.3.2.1 --- Growth and food intake --- p.73 / Chapter 2.3.2.2 --- Organ weights --- p.73 / Chapter 2.3.2.3 --- "Effect of ODA on serum TC, TG and HDL-C" --- p.73 / Chapter 2.3.2.4 --- Effect of ODA feeding on fecal neutral sterol content --- p.77 / Chapter 2.3.2.5 --- Effect of ODA feeding on fecal acidic sterol content --- p.77 / Chapter 2.3.2.6 --- Effect of ODA feeding on intestinal acyl coenzyme A: acyl cholesterol transferase (ACAT) activity --- p.77 / Chapter 2.4 --- Discussion --- p.81 / Chapter CHAPTER 3 --- EFFECT OF OCTADECAENOIC ACIDS ON CHOLESTEROL-REGULATING GENES IN HepG2 / Chapter 3.1 --- Introduction --- p.86 / Chapter 3.1.1 --- HepG2 as a model of cholesterol regulation --- p.86 / Chapter 3.1.2 --- Effect of polyunsaturated fatty acids (PUFAs) on cholesterol regulating genes in cultured cells --- p.87 / Chapter 3.1.3 --- Objectives --- p.89 / Chapter 3.2 --- Materials and Methods --- p.90 / Chapter 3.2.1 --- Cell culture --- p.90 / Chapter 3.2.2 --- "Measurement of SREBP-2, LDLR, HMGR and CYP7A1 protein abundance by Western blotting" --- p.92 / Chapter 3.2.3 --- "Measurement of cellular SREBP-2, LDLR, HMGR, LXR, CYP7A1 and CETP mRNA by real time PCR" --- p.93 / Chapter 3.2.4 --- Statistics --- p.93 / Chapter 3.3 --- Results --- p.95 / Chapter 3.3.1 --- Effect of ODA on HepG2 SREBP-2 immunoreactive mass --- p.95 / Chapter 3.3.2 --- Effect of ODA on HepG2 HMGR immunoreactive mass --- p.95 / Chapter 3.3.3 --- Effect of ODA on HepG2 LDLR immunoreactive mass --- p.95 / Chapter 3.3.4 --- Effect of ODA on HepG2 LXR immunoreactive mass --- p.95 / Chapter 3.3.5 --- Effect of ODA on HepG2 CYP7A1 immunoreactive mass --- p.96 / Chapter 3.3.6 --- Effect of ODA supplementation on HepG2 SREBP-2 mRNA expression --- p.102 / Chapter 3.3.7 --- Effect of ODA supplementation on HepG2 SREBP-2 mRNA expression --- p.102 / Chapter 3.3.8 --- Effect of ODA supplementation on HepG2 LDLR mRNA expression --- p.102 / Chapter 3.3.9 --- Effect of ODA supplementation on HepG2 LXR mRNA expression --- p.106 / Chapter 3.3.10 --- Effect of ODA supplementation on HepG2 CYP7A1 mRNA expression --- p.106 / Chapter 3.3.11 --- Effect of ODA supplementation on HepG2 CETP mRNA expression --- p.106 / Chapter 3.4 --- Discussion --- p.110 / Chapter CHAPTER 4 --- EFFECT OF APPLE POLYPHENOLS ON BLOOD CHOLESTEROL IN HAMSTERS / Chapter 4.1 --- Introduction --- p.114 / Chapter 4.1.1 --- Apple is a commonly consumed fruit worldwide --- p.114 / Chapter 4.1.2 --- Potential health effects of apples --- p.114 / Chapter 4.1.3 --- Abundance of polyphenols in apple --- p.115 / Chapter 4.1.4 --- Fuji variety of apple --- p.116 / Chapter 4.1.5 --- Objectives --- p.116 / Chapter 4.2 --- Materials and Methods --- p.118 / Chapter 4.2.1 --- Isolation of AP --- p.118 / Chapter 4.2.2 --- Characterization of AP extract --- p.118 / Chapter 4.2.3 --- Effect of AP on CETP activity in vitro --- p.118 / Chapter 4.2.4 --- Effect of AP on blood cholesterol in hamsters --- p.119 / Chapter 4.2.4.1 --- Animals --- p.119 / Chapter 4.2.4.2 --- Diets --- p.120 / Chapter 4.2.4.3 --- Plasma lipids measurement --- p.121 / Chapter 4.2.4.4 --- Plasma CETP activity measurement and immunoreactive mass by Western blotting --- p.123 / Chapter 4.2.4.5 --- "Measurement of liver SREBP-2, LDL-R, HMG-R and CYP7A1 protein abundance by Western blotting" --- p.124 / Chapter 4.2.4.6 --- Statistics --- p.124 / Chapter 4.3 --- Results --- p.125 / Chapter 4.3.1 --- Polyphenol content in AP --- p.125 / Chapter 4.3.2 --- Effect of AP on CETP activity in vitro --- p.125 / Chapter 4.3.3 --- Growth and food intake --- p.128 / Chapter 4.3.4 --- Organ weights --- p.128 / Chapter 4.3.5 --- Effect of AP supplementation on the plasma lipid profile of hamsters --- p.131 / Chapter 4.3.6 --- Effect of AP feeding on plasma CETP activity of the hamsters --- p.131 / Chapter 4.3.7 --- Effect of AP on plasma CETP immunoreactive mass --- p.134 / Chapter 4.3.8 --- Effect of AP on liver SREBP-2 immunoreactive mass --- p.134 / Chapter 4.3.9 --- Effect of AP on liver LDLR immunoreactive mass --- p.134 / Chapter 4.3.10 --- Effect of AP on liver HMGR immunoreactive mass --- p.134 / Chapter 4.3.11 --- Effect of AP on liver CYP7A1 immunoreactive mass --- p.134 / Chapter 4.3.12 --- Effect of AP on liver cholesterol level --- p.140 / Chapter 4.4 --- Discussion --- p.142 / Chapter CHAPTER 5 --- CONCLUSION --- p.145 / REFERENCES --- p.148

published_or_final_version / Biological Sciences / Doctoral / Doctor of Philosophy

Atherosclerosis, an inflammatory disease characterized by plaque formation in the arteries, commonly occurs in mammals, including humans, and some avian species. Polyunsaturated n-3 fatty acids have been shown to reduce known mammalian risk factors associated with the development of atherosclerosis in mammals. N-3 polyunsaturated fatty acids (PUFA) have also been linked to improving retinal, neurological, and brain development and functioning. In order to assess the effects of n-3 PUFA on potential risk factors for atherosclerosis in avian species and learning ability, a series of studies were conducted in Monk parrots: 1) alterations comparing a high linoleic acid diet with -linolenic acid (ALA) diet on lipid metabolism, fatty acid conversions, and lipoproteins, 2) the dose response of ALA and comparison with a high docosahexaenoic acid (DHA) diet on lipid metabolism, fatty acid conversions, and markers of oxidation, 3) the effect of a high DHA diet on learning ability, and 4) assessment of growing energy requirement estimations to improve adult health. Monk parrots were able to convert ALA to DHA and also retro-convert DHA/docosapentaenoic acid (DPA) to eicosapentaenoic acid (EPA). Feeding Monk parrots a high ALA diet resulted in a shift in the peak density of the high-density lipoproteins after 70 days. Decreased superoxide dismutase and increased malondialdehyde were observed by day 63 regardless of dietary n-3 PUFA levels or source. Higher plasma phospholipid DHA levels at day 28 were obtained when n-3 PUFA were provided in the diet as DHA rather than ALA (at equivalent amounts). Total plasma cholesterol, free cholesterol, esterified cholesterol, and triacylglycerol concentrations were not altered by increasing dietary n-3 PUFA. An effect of DHA on learning ability could not be concluded due to decreased power from adjusting for an age effect. Additionally, the growing energy needs for Monk parrots through day 23 after hatching were estimated and, unlike previous general equations, accounted for changes in growth energy requirements. These closer energy estimations that accounted for growth energy variations will hopefully prevent negative fluctuations in growth rate which were observed in the study and prevent obese fledgling and young adult birds. In conclusion, Monk parrots are able to benefit from dietary n-3 PUFA provided as either ALA or DHA. Although, dietary DHA may provide more protection against the development of atherosclerosis due to its higher accumulation into plasma phospholipids and retro-conversion to EPA. However, caution should be used when feeding PUFA, as they increase oxidation in the body. While many risk factors for atherosclerosis have been determined in humans and other mammals, some of these do not appear to hold for Monk parrots and possibly other avian species prone to atherosclerosis.

Feline lipid metabolism is a topic for greater exploration due to this specie?s unique characteristics. Cats express limited Delta 6-desaturase activity necessary for conversion of linoleic acid (LA, 18:2n-6) to arachidonic acid (AA, 20:4n-6). The possibility exists that Gamma-linolenic acid (GLA, 18:3n-6) may serve as a precursor of AA in reproductive tissues especially if coupled with chain elongation and a functionally active Delta 5-desaturase. In addition no research has been conducted regarding feline reproductive Delta 8-desaturase activity as an alternate to the production of AA. To investigate desaturation activities, a group of 26 adult female cats were randomly assigned into 1 of 3 groups based on the diet fed: High Linoleic Acid (HL, n=7), Low Linoleic Acid (LL, n=9), and High Gamma-Linolenic Acid (GLA, n=10).The diets were fed for 300 days prior to ovariohysterectomy at which time EDTA plasma and ovarian, uterine, and subcutaneous adipose tissues were collected. Homogenates of each tissue were prepared and frozen in aliquots at -80 degrees C. Total lipids were extracted from the plasma and tissue homogenates followed by phospholipid (PL) fractionation via thin layer chromatography and fatty acid (FA) analyses by gas chromatography. The Shapiro-Wilks test was used to determine normal distribution of FA data followed by One-Way ANOVA and Tukey multiple comparisons (p<0.05). Plasma PLs were significantly increased in both GLA and dihomo-Gamma-linolenic acid (DGLA, 20:3n-6Delta8,11,14) in the GLA group and statistically increased in 20:2n-6 and 20:3n-6(Delta5,11,14) in the HL group. Uterine tissue homogenates had significantly increased amounts of DGLA and AA, however ovarian tissue showed an increase of only DGLA. Adipose tissue FAs showed significantly high amounts of DGLA in the GLA group. It is concluded that a high GLA diet results in increased AA in uterine, but not ovarian, tissues and thus may supply eicosanoid precursors in support of reproduction. The presence of increased amounts of 20:3n-6(Delta5,11,14) and not AA in the plasma and uterine tissues in the HL group suggests that Delta6-desaturase cannot be induced and that Delta8-desaturase is not active when feeding high dietary LA. Furthermore, the increase in DGLA may provide an adipose storage reservoir for additional conversion under times of metabolic need. These data support the presence of a functionally active Delta5-desaturase in uterine, but not ovarian, tissues. The findings also suggest that increased dietary GLA may be used to meet the AA requirements for reproduction in cats in the absence of an animal based pre-formed source of AA.

Conjugated linoleic acid (CLA) is predominantly found in foods of ruminant origin such as milk and processed cheese, and has gained much interest recently due to its beneficial health and biological effects on animals and humans. / The bioconversion of linoleic acid (LA) and linolenic acid (LNA) by a selected Bifidobacterium from healthy infant feces was studied. Bifidobacterium breve JKL03 had the ability to convert linolenic acid (0.2 mg/ml) to CLNA in fermentation of skim milk medium for 24 h up to a yield of 72.0% (up to 74.7% under aerobic conditions) and linoleic acid (0.2 mg/ml) into CLA by fermentation in skim milk medium for 24 h up to a yield of 23.9% (up to 28.0% under aerobic conditions). / B. breve JKL03 was also co-fermented with Lactobacillus acidophilus (NCFMRTM strain), a commonly added starter culture, to observe the resulting effects on growth during fermentation for yogurt production. Fermentation of LNA in skim milk with B. breve JKL03 and L. acidophilus (NCFM) maintained high CLNA production level. On the other hand, CLA production in the same media with both strains did not exhibit as high level as with the single B. breve. / These results are important for the advancement of knowledge on the production of CLA and CLNA in dairy products and for knowledge on the basic metabolic mechanisms for such conversion.