• Proceedings of the PSK Conference
• /
• 2003.04a
• /
• pp.263.2-263.2
• /
• 2003

There is now increasing evidence that free radicals and active oxygen species are involved in a variety of pathological events. Free radical-mediated cell damage and free radical attack on polyunsaturated fatty acids result in the formation of lipid radicals. These lipid radicals react readily with molecular oxygen to produce peroxy radicals responsible for initiating lipid peroxidation. The peroxidation of cellular membrane lipid can lead to cell necrosis and considered to ve implicated in a number of pathophysiological conditions including liver disease. (omitted)

• Nutrition Research and Practice
• /
• v.3 no.3
• /
• pp.200-207
• /
• 2009

This study examined the effects of com gluten (CG) and its hydrolysate consumptions on weight reduction in rats fed a high-fat diet. Eight-month-old male Sprague-Dawley rats (n=40) were fed a high-fat diet (40% calorie as fat) for 4 weeks. They were then randomly divided into four groups and fed the isocaloric diets with different protein sources for 8 weeks. The protein sources were casein (control group), intact CG (CG group), CG hydrolysate A (CGHA group, 30% of protein as peptides and 70% as free amino acids) and CG hydrolysate P (CGHP group, 93% of protein as peptides and 7% as free amino acids). Body weight gain, adipose tissue weights, nitrogen balance, absorptions of energy, protein and fat, lipid profiles in plasma, liver and feces and hepatic activities of camitine palmitoyl transferase (CPT), fatty acid synthase (FAS), malic enzyme (ME) and glucose-6-phosphate dehydrogenase (G6PDH) were assessed. The CGHA diet had the highest amount of BCAAs, especially leucine, and most of them existed as free amino acid forms. The CGHA group showed significant weight reduction and negative nitrogen balance. Protein absorption and apparent protein digestibility in the CGHA group were significantly lower than those in other groups. Adipose tissue weights were the lowest in the CGHA group. Activity of CPT tended to be higher in the CGHA group than in other groups and those of FAS, ME and G6PDH were significantly lower in the CGHA group than in other groups. In conclusion, the CGHA diet which had relatively high amounts of free amino acids and BCAAs, especially leucine, had a weight reduction effect by lowering adipose tissue weight and the activities of FAS, ME and G6PDH in experimental animals, but it seemed to be a negative result induced by lowering protein absorption, increasing urinary nitrogen excretion and protein catabolism.

• Asian-Australasian Journal of Animal Sciences
• /
• v.17 no.8
• /
• pp.1162-1167
• /
• 2004

The present study was designed to define whether dietary conjugated linoleic acid (CLA) could affect antioxidant enzymes including superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), catalase (CAT), and glutathione S transferase (GST), and the level of malondialdehyde (MDA), a marker of lipid peroxidation, in the small intestine and liver from broiler chickens. A total of twenty-four 3 wk-old male broiler chickens were assigned to three dietary treatments (1.5% corn oil, 0.75% corn oil plus 0.75% CLA, and 1.5% CLA, isocalorically), and fed a grower-finisher diet from 22 to 35 days. In the small intestinal mucosae, the specific activities of SOD, GSH-Px, CAT, and GST, and the level of MDA were not substantially influenced by dietary CLA. In the liver, the specific activities of SOD, GSH-Px, and GST, and the level of MDA were also unaffected by dietary CLA at the level of either 0.75% or 1.5% compared with corn oil at the level of 1.5%. However, the broiler chickens fed the diet containing 1.5% CLA resulted in a significant increase in peroxisomal CAT activity and a marked decrease in total lipid and non-esterified fatty acids (NEFA) from liver tissues compared with those fed the diet containing 1.5% corn oil. In conclusion, ability of CLA to increase hepatic CAT activity suggest that dietary CLA may affect, at least in part, antioxidant defense system as well as lipid metabolism in the liver of broiler chickens.

• Asian-Australasian Journal of Animal Sciences
• /
• v.17 no.7
• /
• pp.936-941
• /
• 2004

Four rumen-cannulated cows (330 kg average weight at 4 years) were used to evaluate the supplement of ensiled cassava tops (ECT) (variety KM 94, 39% DM) on rumen functions, thyroid hormones and liver enzymes. The treatments, arranged in a 4 $\times$4 Latin square design, were ECT at 0, 50, 100 and 150 g CP 100 kg$^{-1}$ body weight (BW), and a basal diet of urea-treated fresh rice straw (UFRS) ad libitum and 1.1 kg dry matter (DM) cassava root meal (CRM) in each 30 day study period. The results showed a continuous decrease in dry matter intake (DMI) of UFRS with increasing level of ECT supplement (p<0.001). The highest total DMI was observed for treatment ECT$_{150}$ (2.68 kg DM 100 kg$^{-1}$ BW day$^{-1}$) followed by treatments ECT$_{100}$, ECT$_{50}$ and ECT$_{0}$, with 2.47, 2.24 and 2.06 kg DM 100 kg$^{-1}$ BW⋅day$^{-1}$, respectively. Increasing levels of ECT supplement increased the concentration of total volatile fatty acids (p<0.05) and ammonia nitrogen (p<0.05) and resulted in a decrease in pH (p<0.05). Overall average plasma triiodothyronine and thyroxine concentrations were 0.80, 0.82, 0.85 and 0.69 ng ml$^{-1}$ (p>0.05), and 50.9, 49.5, 50.7 and 42.4 ng ml-1 (p>0.05) for treatments ECT$_{0}$, ECT$_{50}$, ECT$_{100}$ and ECT$_{150}$, respectively. There were non-significant differences in alanine aminotransferase and aspartate aminotransferase among treatments. It is concluded that ECT is a valuable protein-rich feed supplement to cattle, and the highest level of on average 2.48 kg DM ECT per cow and day (28% of total DMI) did not significantly affect thyroid gland hormones and liver enzymes in cows.

• Journal of Nutrition and Health
• /
• v.25 no.6
• /
• pp.476-484
• /
• 1992

The influence of selenuium deficiency and fish oil on lipid peoxidation status and fatty acid composition of tissues(plasma aorta and liver) was studied. Male Sprague Dawley rats were fed for eight weeks semipurified diets containing 7% corn oil(by weight) or 5, 5% fish oil(MaxEPA) plus 1.5% corn oil with oil with or without selenium status (glutathione peroxidase activity and selenium levels) were significantly lower in the rats given inadequate selenium in plasma aorta (p<0.02 and p<0.001 respectively) gut not that in plasma Selenium supplementation decreased hepatic MDA levels(p<0.02) Increases in the levels of 20:5(n-3) 22:5(n-3), 22:6(n-3) 20:3(n-6) and a decrease in the level of 20:4(n-6) were observed in plasma total lipids and aortic and hepatic phospholipids when fish oil was fed. Though selenium supplementation increased the level of n-3 fatty acids(such as 22:6(n-3)) in plsama and the aorta is overall effect was smaller than the effect of fish oil feeding. These data suggest that selenium may play a significant but minor role in protecting against lipid peroxide-tion even when vitamin E intakes are in excess of current recommendations in both corn oil and fish oil diets.

• Journal of Nutrition and Health
• /
• v.24 no.4
• /
• pp.314-325
• /
• 1991

To compare the hypolipidemic effects of n6 and n3 PUFA at different fat levels, male Sprague Dawley rats were fed either low fat (LF, 10% Cal) or high fat (HF, 40% Cal) diet which was different only in fatty acid composition for 6 weeks. Dietary fats were beef tallow, corn oil, perilla oil, and fish oil concentrate as a source of saturated fatty acid, n6 linoleic acid(LA). n3 ${\alpha}-linolenic$ acid(LL) and n3 eicosapentaenoic acid(EPA)+docosahexaenoic acid(DHA), respectively. VLDL fraction was separated by ultracentrifugation and chemical composition was determined by thin layer chromatography. Plasma cholesterol level was increased by n6 LA but decreased by n3 LL and n3 EPA in LF and HF diets, and the hypocholesterolemic effect of n3 EPA was most significant in HF diet. HDL-Chol level was raised by n6 LA in LF and HF diets, but significantly reduced by n3 EPA in HF. Plasma TG level was reduced by n6 LA n3 LL and EPA in LF and HF with the reduction of lipogenic enzyme activity only by n3 PUFAs. The proportion of TG in VLDL fraction was significantly lowered by n3 EPA in LF and HF. The proportion of apo-B in VLDL fraction was not changed in LF, but was significantly decreased in HF by n3 EPA. Therefore, the hypotriglyceridemic effect of n3 PUFA could be from the reduced lipogenesis in liver and resulted in the depressed secretion of TG as VLDL in LF and HF with significant lower production of apoB in HF diet.

• Journal of Life Science
• /
• v.32 no.4
• /
• pp.318-324
• /
• 2022

PPARγ and C/EBPα are master adipogenic transcription factors (TFs) required for adipose tissue development. They control the induction of many adipocyte genes and the early phase of adipogenesis in the embryonic development of adipose tissue. Adipose tissue continues to expand after birth, which, as a late phase of adipogenesis, requires the lipogenesis of adipocytes. In particular, the liver and adipose tissues are major sites for de novo lipogenesis (DNL), where carbohydrates are primarily converted to fatty acids. Furthermore, fatty acids are esterified with glycerol-3-phosphate to produce triglyceride, a major source of lipid droplets in adipocytes. Hepatic DNL has been actively studied, but the DNL of adipocytes in vivo remains not fully understood. Thus, an understanding of lipogenesis and adipose expansion may provide therapeutic opportunities for obesity, type 2 diabetes, and metabolic diseases. In adipocytes, DNL gene expression is transcriptionally regulated by lipogenesis coactivators, as well as by lipogenic TFs such as ChREBP and SREBP1a. Recent in vivo studies have revealed new insights into the lipogenesis gene expression and adipose expansion. Future detailed molecular mechanism studies will determine how nutrients and metabolism regulate DNL and adipose expansion. This review will summarize recent updates of DNL in adipocytes and adipose expansion in terms of transcriptional regulation.

• Proceedings of the Korean Aquaculture Society Conference
• /
• 2003.10a
• /
• pp.78-79
• /
• 2003

Effects of dietary lipid level and source (squid liver oil being rich in n-3 HUFA, soybean oil being rich in 18:2n-6, and linseed oil being rich in 18:3n-3) in fishmeal-based diet on growth and body composition of grower sunshine bass raised in seawater were investigated. Fifteen grower (an initial weight of 146.8$\pm$0.23 g) sunshine bass were randomly distributed into 27 of 250 L fiber reinforced plastic flow-through tanks. Fish were hand-fed to satiety twice daily for 6 days a week throughout the feeding trial. Survival was over 97% and not significantly affected by either dietary lipid level or lipid source (n-3 highly unusaturated fatty acid, HUFA). Weight gain of fish tended to improve with dietary n-3 HUFA level up to 2.9%, but sharply decreased at 3.5%. The best weight gain was obtained in fish fed the diet supplemented with 6% squid liver oil and 3% soybean oil. FER and PER were not significantly affected by either dietary lipid level or dietary lipid source. The lowest moisture content of the whole body was observed in fish fed the diet supplemented with 12% squid liver oil and highest for the diet supplemented with 9% linseed oil, respectively. Protein content of fish was not significantly affected by either dietary lipid level or dietary lipid source. However, lipid content of the whole fish tended to increase with an increase of either dietary lipid level or dietary n-3 HUFA level, except for fish fed the diet supplemented with 9% linseed oil. Ash content of fish fed the diet with no supplementation of oil was highest and lowest for the diet supplemented with 9% soybean oil, respectively. Significant differences in saturated fatty acids (16:0, 18:0 and 24:0), monoene (18:1n-9), 18:2n-6, 20:5n-3 and sum of n-3 HFUA of fish were observed. In considering these results, it could be concluded that supplementation of 9% oil combined with 6% squid liver oil and 3% soybean oil into fishmeal-based diet was the most recommendable for growth of grower sunshine bass raised in seawater.

• Journal of Aquaculture
• /
• v.19 no.2
• /
• pp.140-146
• /
• 2006

This study was conducted to investigate the effect of dietary oxidized oil and ${\alpha}$-tocopherol level on growth and body composition of juvenile flounder. To prepare oxidized diets, squid liver oil was oxidized by aeration at $25^{\circ}C$ for 30 days. The six diets were prepared to contain 6% fresh or oxidized squid liver oil as the lipid sources in combination with three levels of ${\alpha}$-tocopheryl acetate at 0, 80 and 800 mg/kg diet. Triplicate groups of fish ($3.9{\pm}0.1$) were fed to apparent satiation twice a day for 8 weeks. Survival was not significantly different among treatments. Weight gain, feed efficiency, daily feed intake, protein efficiency ratio and condition factor of fish fed the fresh oil diets were significantly higher than those of fish fed the oxidized oil diets (P<0.05). The increase of the vitamin E level in diets did not result in any significant improvement on growth performance of fish fed both oil diets. The vitamin E content of the liver and dorsal muscle increased with increasing dietary vitamin E level at both oil diet groups. A decreasing trend in vitamin E content of the tissues was observed in fish fed the oxidized oil diets at the same dietary vitamin E level. Significantly higher moisture content and lower crude lipid content were observed in the whole body of fish fed the oxidized oil diets than fish fed the fresh oil diets (P<0.05). Dietary lipid source affected the fatty acid content of the whole body; higher contents of saturated and monoenoic fatty acids, and lower n-3 HUFA contents such as 20:5n-3 and 22:6n-3 were observed in fish fed the oxidized oil diets than those of fish fed fresh oil diets. The results of this study suggest that the dietary oxidized oil may impair the growth performance, and an increase in ${\alpha}$-tocopheryl acetate supplementation have no beneficial effect on growth and feed efficiency of juvenile flounder.

• Journal of the Korean Applied Science and Technology
• /
• v.37 no.3
• /
• pp.398-408
• /
• 2020

The purpose of the present study was to investigate the mechanism of metabolic partitioning between oxidization and esterification of liver fatty acids synthesized and secreted by the liver from egg yolk-fed laboratory rats. Animals were divided into four groups and orally administered egg yolk daily for 30 days: CON (control group, 1.0 g of saline solution), T1 (1.0 g of pork belly oil), T2 (1.0 g of egg yolk), and T3 (1.0 g of pork belly oil and 1.0 g of egg yolk, alternatively each week). The accumulation rate of [¹⁴C]-labelled lipid in liver was lowest in T2 among all treatments (P<0.05). Phospholipid secretion was higher in T2 than other treatments (P<0.05). The triglycerol secretion was highest in T1 and higher in the order of CON, T3, and T2 (P<0.05). Metabolic partitioning rate of phospholipid from total glycerolipid was highest in T2, followed by T3, CON and T1 (P<0.05). The ¹⁴CO₂ production from total glycerolipid was the highest in T2 and showed a high oxidation rate compared to CON, T1, and T3 (P<0.05). Metabolic partitioning of glycerolipid from the liver decreased in triglycerol of T2 compared to CON, T1, and T3, whereas phospholipids of T2 increased (P<0.05).