Effects of Long‐Chain and Medium‐Chain Fatty Acids on Apoptosis and Oxidative Stress in Human Liver Cells with Steatosis

Nonalcoholic fatty liver disease (NAFLD) is closely associated with obesity‐related metabolic complications, which caused by excess energy intake and physical inactivity apart from genetic defects. The mechanisms that promote disease progression from NAFLD to further liver injury are still unclear. We hypothesize that the progression involved “2nd hit” is strongly influenced by the type of fatty acids in diets. Flow cytometric analysis showed that medium‐chain fatty acid (MCFA) markedly decreased the percentage of late apoptotic and necrotic cells compared with long‐chain fatty acid (LCFA), and MCFA inhibited the activities of caspase‐3 and ‐9 in human liver cells with steatosis. Western blot analysis found that the levels of inflammatory markers (interleukin [IL]‐6, IL‐1‐β, and tumor necrosis factor‐α) were substantially reduced by MCFA compared with LCFA. Proteomic analysis further showed that LCFA inhibited the expression of antioxidant enzymes, and increased the expression of proteins associated with oxidative stress. It was found that LCFA (palmitate), not MCFA induced apoptosis, oxidative stress and chronic inflammatory responses in the hepatic cells with steatosis. In conclusion, reasonable selection of dietary fats has potential to translate therapeutically by ameliorating disease progression in patients with NAFLD.     

Concentration of n‐3 polyunsaturated fatty acids in cholesterol‐reduced cod‐liver oil by lipases

This study was conducted to elucidate the effects of different lipases originated from Candida rugosa (CR), porcine pancreas (PP) and Aspergillus niger (AN) on the degree of hydrolysis (DH) in cholesterol‐reduced cod‐liver oil (87.5%) and evaluate the changes in n‐3 polyunsaturated fatty acid concentrations in the oil hydrolysed by the lipases. The lipase‐catalysed hydrolysis of cholesterol‐reduced cod‐liver oil was performed at 37 °C for 8 h. Among all the lipase samples studied, DH in the oil after lipase‐catalysed hydrolysis followed the decreasing order: CR lipase (70.01%) > PP lipase (26.18%) > AN lipase (18.57%). Triacylglycerol levels in the oil hydrolysed by all the lipases studied decreased, while mono‐ and diacylglycerol levels increased during lipase‐catalysed hydrolysis. The eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) concentrations in cholesterol‐reduced cod‐liver oil hydrolysed by the CR lipase were remarkably higher than those by the PP or AN lipase. Thus, it is suggested in this study that the CR lipase appears to be most suitable for producing and n‐3 polyunsaturated fatty acids including EPA and DHA concentrates from cholesterol‐reduced cod‐liver oil.     

Plasma phospholipids n‐3 polyunsaturated fatty acid is associated with metabolic syndrome

The relationship between n‐3 PUFA and metabolic syndrome (MS) is not clear. The aim of this study was to examine relationships between plasma phospholipids (PL) n‐3 PUFA and MS in Chinese subjects. Nine hundred and twenty‐nine subjects were recruited in Hangzhou, China. Two hundred and ten (183 males, 27 females) with MS and 719 (545 males, 174 females) healthy subjects were identified in this cross‐sectional study. The prevalence of MS in females (24.56%) was significantly higher than that in males (10.04%) in this population. Total PUFA (p<0.001), n‐3 PUFA (p<0.001), and n‐3:n‐6 (p<0.001) were significantly lower in MS subjects compared to healthy subjects. Plasma phospholipid (PL), n‐3 PUFA was significantly inversely associated with MS (p=0.013). In addition, subjects with high levels of PL total fatty acids (FA) had a more than threefold higher likelihood of MS (OR=3.44, 95% CI=1.60–7.39) than the subjects with low levels of PL total FA. Our results suggest that plasma PL n‐3 PUFA was significantly inversely associated with MS, while high total FA were positively associated with MS in Chinese.     

Production of trans‐Free Margarine with Stearidonic Acid Soybean and High‐Stearate Soybean Oils‐Based Structured Lipid

Abstract: Omega‐3 fatty acids (n‐3 FAs) have been positively associated with prevention and treatment of chronic diseases. Intake of high amounts of trans fatty acids (TFAs) is correlated with increased risk of coronary heart disease, inflammation, and cancer. Structured lipid (SL) was synthesized using stearidonic acid (SDA) soybean oil and high‐stearate soybean oil catalyzed by Lipozyme^® TLIM lipase. The SL was compared to extracted fat (EF) from a commercial brand for FA profile, sn‐2 positional FAs, triacylglycerol (TAG) profile, polymorphism, thermal behavior, oxidative stability, and solid fat content (SFC). Both SL and EF had similar saturated FA (about 31 mol%) and unsaturated FA (about 68 mol%), but SL had a much lower n‐6/n‐3 ratio (1.1) than EF (5.8). SL had 10.5 mol% SDA. After short‐path distillation, a loss of 53.9% was observed in the total tocopherol content of SL. The tocopherols were lost as free tocopherols. SL and EF had similar melting profile, β’ polymorph, and oxidative stability. Margarine was formulated using SL (SLM) and EF (RCM, reformulated commercial margarine). No sensory difference was observed between the 2 margarines. The SL synthesized in this study contained no TFA and possessed desirable polymorphism, thermal properties, and SFC for formulation of soft margarine. The margarine produced with this SL was trans‐free and SDA‐enriched. Practical Application: The current research increases the food applications of stearidonic acid (SDA) soybean oil. trans‐Free SDA containing SL was synthesized with desirable polymorph, thermal properties, and SFC for formulation of soft margarine. The margarine produced with this SL had no trans fat and had a low n‐6/n‐3 ratio. This may help in reducing trans fat intake in our diet while increasing n‐3 FA intake.     

Fatty acid and fat‐soluble antioxidant concentrations in milk from high‐ and low‐input conventional and organic systems: seasonal variation

BACKGROUND: Previous studies showed differences in fatty acid (FA) and antioxidant profiles between organic and conventional milk. However, they did not (a) investigate seasonal differences, (b) include non‐organic, low‐input systems or (c) compare individual carotenoids, stereoisomers of α‐tocopherol or isomers of conjugated linoleic acid. This survey‐based study compares milk from three production systems: (i) high‐input, conventional (10 farms); (ii) low‐input, organic (10 farms); and (iii) low‐input non‐organic (5 farms). Samples were taken during the outdoor grazing (78 samples) and indoor periods (31 samples). RESULTS: During the outdoor grazing period, on average, milk from the low‐input systems had lower saturated FAs, but higher mono‐ and polyunsaturated FA concentrations compared with milk from the high‐input system. Milk from both the low‐input organic and non‐organic systems had significantly higher concentrations of nutritionally desirable FAs and antioxidants—conjugated linoleic (60% and 99%, respectively) and α‐linolenic (39% and 31%, respectively) acids, α‐tocopherol (33% and 50%, respectively) and carotenoids (33% and 80%, respectively)—compared with milk from the high‐input system. Milk composition differed significantly between the two low‐input systems during the second half of the grazing period only; with milk from non‐organic cows being higher in antioxidants, and conjugated linoleic acid, and that from organic cows in α‐linolenic acid. In contrast, few significant differences in composition were detected between high‐input and low‐input organic systems when cows were housed. CONCLUSIONS: Milk composition is affected by production systems by mechanisms likely to be linked to the stage and length of the grazing period, and diet composition, which will influence subsequent processing, and sensory and potential nutritional qualities of the milk. Copyright © 2008 Society of Chemical Industry     

Effects of Trans and Conjugated LC N‐3 Polyunsaturated Fatty Acids on Lipid Composition and Abdominal Fat Weight in Rats

ABSTRACT: Trans and conjugated fatty acids may exhibit either beneficial or detrimental bioactive effects depending on their metabolic properties. This study was conducted to elucidate if isomerization and conjugation of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) demonstrate more favorable bioactivity on lipid metabolism compared to unmodified EPA and DHA. The effects of dietary intake of trans and conjugated forms of EPA and DHA on lipid metabolism were evaluated in animal trials and compared to a control group fed soybean oil. None of the experimental diets showed significant differences from the control in terms of body weight; however, the white adipose tissue weight of rodents fed trans DHA, conjugated EPA (CEPA), and conjugated DHA (CDHA) was significantly lower than the control. Triacylglycerol levels in plasma were significantly decreased in groups fed trans DHA (17.2 mg/dL) and CDHA (31.9 mg/dL) relative to the control (51.3 mg/dL). The total cholesterol concentrations were significantly lower than the control (68.0 mg/dL) in all experimental groups (47.3 to 53.7 mg/dL) except CEPA (58.3 mg/dL). Fatty acid compositions of lipids extracted from rodent livers were influenced by the dietary fatty acid profiles, with all groups showing higher concentrations of stearic acid and lower levels of linoleic acid compared to the control. Rodents fed trans DHA did not have detectable levels of these fatty acid isomers in their livers, suggesting either quick metabolism or a difficulty with bio‐absorption.     

Hypolipidemic Activity of Peony Seed Oil Rich in α‐Linolenic,is Mediated Through Inhibition of Lipogenesis and Upregulation of Fatty Acid β‐Oxidation

Peony seed oil (PSO) is a new resource food rich in α‐Linolenic Acid(ALA) (38.66%). The objective of this study was to assess the modulatory effect of PSO on lipid metabolism. Lard oil, safflower oil (SFO), and PSO were fed to wistar rats with 1% cholesterol in the diet for 60 d. Serum and liver lipids showed significant decrease in total cholesterol (TC), triglyceride (TG), and low density lipoprotein‐cholesterol (LDL‐C) levels in PSO fed rats compared to lard oil and SFO fed rats. ALA, eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA), contents were significantly increased, whereas linoleic acid (LA), arachidonic acid (AA) levels decreased in serum and liver of PSO fed rats. Feeding PSO increased ALA level and decreased n‐6 to n‐3 polyunsaturated fatty acid (PUFA) ratio. The hypolipidemic result of PSO indicated that PSO participated in the regulation of plasma lipid concentration and cholesterol metabolism in liver. The decreased expression of sterol regulatory element‐binding proteins 1C (SREBP‐1c), acetyl‐CoA carboxylase (ACC), and fatty acid synthase (FAS)‐reduced lipid synthesis; Activation of peroxisome proliferator–activator receptor (PPARα) accompanied by increase of uncoupling protein2 (UP2) and acyl‐CoA oxidase (AOX) stimulated lipid metabolism and exerted an antiobesity effect via increasing energy expenditure for prevention of obesity.     

Performance,carcass cut‐up and fatty acids deposition in broilers fed different levels of pellet‐processed flaxseed

The effects of flaxseed (FS) processing and inclusion levels on broiler performance and fatty acid deposition were examined. FS was provided as whole seed, ground or pellet‐then‐mashed at a dietary level of 0, 12 or 14% during days 1 to 21. These levels represented control, threshold and over‐threshold, respectively. During days 22 to 40, the threshold level was increased to 15%, while the over‐threshold level increased to 17%. After 21 days of feeding, the performance of birds fed a diet with 12% pellet‐then‐mashed FS were comparable (p > 0.05) with those fed mashed control diet, but superior to those fed a diet of whole FS (p < 0.05). There was interaction (p < 0.05) between diet processing and FS level on weight gain, with pellet‐then‐mash processing being more effective at the 12% FS inclusion level than at the 14% level in improving performance. The beneficial processing effect on performance diminished during days 22 to 40. Furthermore, carcass cut‐up percentage was not affected (p > 0.05) by the treatments, except that increased FS level resulted in smaller fat‐pad and larger liver (p < 0.05). Birds deposited omega‐3 (n‐3) fatty acids in breast and thigh muscle the most with higher FS inclusion and pellet‐then‐mash processing. On day 40, the total n‐3 fatty acids made up 22.1 and 24.4% in the muscle lipids of breast and thigh samples from birds fed pellet‐then‐mashed FS at the level of 12% during days 1 to 21 and at the level of 15% during days 22 to 40, respectively. These values were higher (p < 0.05) than those found in birds fed diets of similar FS levels but as whole seed or ground seed. Up to 12% pellet‐processed FS can be incorporated into broiler diets with satisfactory growth, while maximizing n‐3 fatty acid deposition in the tissues. Copyright © 2005 Society of Chemical Industry     

Proximate and fatty acid compositions and sensory acceptability of Hispanic consumers towards rib‐eye steaks from forage‐finished steers

Proximate and fatty acid compositions and sensory acceptability of rib‐eye steaks (fresh and 6 months frozen‐stored) from three forage‐finished steers [S1 (bermudagrass + ryegrass, etc.); S2 (bermudagrass + ryegrass + berseem, etc.); S3 (bermudagrass+berseem+soybean+brown midrib sorghum, etc.)] and one commercial steak (C), cooked by one‐sided and/or two‐sided grilling, were evaluated. All forage‐finished steaks had lower [omega‐6/omega‐3] ratios than C. Sensory liking was assessed by Hispanic consumers. Raw C steak had higher fat and lower protein contents than others (S1, S2 and S3). Concerning raw steaks, S3 had higher liking scores for overall appearance and fat appearance than others. Two cooking methods did not cause significant differences in sensory liking. Juiciness and overall liking of cooked C and S3 (one‐sided grilling) steaks were not significantly different. Purchase intent (after knowing health benefits of forage‐finished steaks) increased from 62.0–73.8% to 69.8–85.7%. Forage‐finished steaks showed a potentially healthier lipid profile than grain‐finished steaks and had market potential towards Hispanic population.     

Mitochondria‐Mediated Pathogenesis and Therapeutics for Non‐Alcoholic Fatty Liver Disease

Non‐alcoholic fatty liver disease (NAFLD) has become a worldwide epidemic over the last decade. Remarkable progress has been made in understanding the pathogenesis of NAFLD and, subsequently, in developing medications to treat this disease. Although the mechanisms of NAFLD are complex and multifactorial, accumulating and emerging evidence indicates that mitochondria play a critical role in the pathogenesis and progression of NAFLD. Pharmacologic therapies acting on mitochondria may therefore pave the way to novel strategies for the prevention and protection against NAFLD. This review focuses on new insights into the role of hepatic mitochondrial dysfunction in NAFLD, and summarizes recent studies on mitochondria‐centric therapies for NAFLD utilizing new medications or repurposing of currently available drugs. Although some studies presented may feature controversial results or are still in lack of clinical verification, it is undoubted that medications that may spare the mitochondria from multiple levels of damage are highly promising, and have begun to be used with some degree of success.     

n‐3 Omega fatty acids: a review of current knowledge

The very long chain polyunsaturated fatty acids (PUFAs) (C18–C22) and n‐3 Omega PUFAs are apparently widely accepted as a part of modern nutrition because of their beneficial effects on metabolism. Most significantly, the reported protective effect of the n‐3 omega fatty acids in relation to cardiovascular inflammatory diseases and cancer has led people to consider these fatty acids more beneficial than other dietary supplements. Unfortunately, there is a lack of studies relating to the physical performance increasing effect in sports diets, cholesterol‐reducing effect in meat technology, effects on human serum profile, the application dose and the side effects with/without omega‐6 PUFAs, which has left us with several crucial unanswered questions. We still do not know the correct dose of n‐3 omega and the correct ratio of n‐3 omega to n‐6 omega or their possible contraindications when combined with drugs, other foods and herbal supplements. Another reported aspect of n‐3 omega PUFAs is that they protect and even enhance the effect in medical treatment of important diseases such as Alzheimer’s, multiple sclerosis and cancer. These reports led to PUFAs becoming one of the most accepted and consumed food supplements. Despite this weight of evidence and the considerable current use, there is still a need for studies, which will determine whether the n‐3 omega fatty acids are in fact important functional supplements with no adverse effects. This review will attempt to outline the current position of n‐3 omega fatty acids in the field of clinical nutrition and healthcare and outline the studies needed to determine whether there are significant advantages in taking them as food supplement without any adverse effects.