• Bulletin of the Korean Chemical Society
• /
• v.22 no.2
• /
• pp.139-140
• /
• 2001

• Bulletin of the Korean Chemical Society
• /
• v.33 no.7
• /
• pp.2187-2192
• /
• 2012

This study presents a facile way synthesizing disc-like lipid bilyaer nanostructures with a cationic amphiphilic polyelectrolyte. The cationic amphiphilic polyelectrolyte was in a form of partially quarternized copolymer and was synthesized with 2-(dimethylamino)ethyl methacrylate and stearyl methacrylate. At some concentration ranges of the polymer, the addition of the polymer to lipid components during the preparation of bilayer nanostructures resulted in discs with a fairly high yield (~99%). The mechanism for the formation of the nanostructures was discussed based on the physical properties of these nanostructures and by comparing the nanostructures obtained with an anionic amphiphilic polyelectrolyte.

• Preventive Nutrition and Food Science
• /
• v.22 no.3
• /
• pp.172-183
• /
• 2017

Vitamin A and its metabolites modulate insulin resistance and regulate stearoyl-CoA desaturase 1 (SCD1), which are also known to affect insulin resistance. Here, we tested, whether vitamin A-mediated changes in insulin resistance markers are associated with SCD1 regulation or not. For this purpose, 30-week old male lean and glucose-intolerant obese rats of WNIN/GR-Ob strain were given either a stock or vitamin A-enriched diet, i.e. 2.6 mg or 129 mg vitamin A/kg diet, for 14 weeks. Compared to the stock diet, vitamin A-enriched diet feeding improved hyperglycemia and glucose-clearance rate in obese rats and no such changes were seen in lean rats receiving identical diets. These changes were corroborated with concomitant increase in circulatory insulin and glycogen levels of liver and muscle (whose insulin signaling pathway genes were up-regulated) in obese rats. Further, the observed increase in muscle glycogen content in these obese rats could be explained by increased levels of the active form of glycogen synthase, the key regulator of glycogen synthesis pathway, possibly inactivated through increased phosphorylation of its upstream inhibitor, glycogen synthase kinase. However, the unaltered hepatic SCD1 protein expression (despite decreased mRNA level) and increased muscle-SCD1 expression (both at gene and protein levels) suggest that vitamin A-mediated changes on glucose metabolism are not associated with SCD1 regulation. Chronic consumption of vitamin A-enriched diet improved hyperglycemia and glucose-intolerance, possibly, through the regulation of intracellular signaling and glycogen synthesis pathways of muscle and liver, but not associated with SCD1.

• Reproductive and Developmental Biology
• /
• v.40 no.2
• /
• pp.15-22
• /
• 2016

As a one of unsaturated fatty acid, polyunsaturated fatty acids (PUFAs) have multiple actions: as precursor of prostaglandins (PGs), steroid hormone synthesis and energy production in animal reproduction. PUFAs, which include omega-3 (n-3) and omega-6 (n-6), are derived from the diet and changed by diet, species, breed and season. The plasma membrane of spermatozoa in mammals contain various PUFAs. These composition of PUFAs regulate the membrane fluidity and cause lipid peroxidation via generation of reactive oxygen species (ROS). Induced lipid peroxidation by ROS decreased viability and motility of spermatozoa, and it is reduced by addition of antioxidant and low concentration of PUFAs. Because oocytes of animal have a high lipid components, process of oocyte maturation and embryo development are influenced by PUFAs. In in vitro study, oocyte maturation, embryo development, intracellular cAMP and MAPK activity were increased by treatment of n-3 ${\alpha}$-linolenic acid (ALA) during maturation, whereas n-6 linoleic acid (LA) negatively influenced. Also, inhibition of fatty acid metabolism in oocyte influenced blastocyst formation of cattle. PGs are synthesized from PUFAs and various PUFAs influence PGs via regulation of PG-endoperoxide synthase (PTGS). Steroid hormone synthesis from cholesterol is regulated by expression of steroid acute regulator (StAR) protein and mRNA. Exogenous n-3 and n-6 PUFAs altered sex hormone in animal through stimulate or inhibit StAR activity. Because PUFAs altered PG and steroid hormone synthesis, follicular development was influenced by PUFAs. This effect of unsaturated fatty acid could provide information for improvement of reproductive ability in animals.

• Asian-Australasian Journal of Animal Sciences
• /
• v.29 no.12
• /
• pp.1748-1755
• /
• 2016

An experiment was conducted to investigate the effect of niacin supplementation on hepatic lipid metabolism in rabbits. Rex Rabbits (90 d, n = 32) were allocated to two equal treatment groups: Fed basal diet (control) or fed basal diet with additional 200 mg/kg niacin supplementation (niacin). The results show that niacin significantly increased the levels of plasma adiponectin, hepatic apoprotein B and hepatic leptin receptors mRNA (p<0.05), but significantly decreased the hepatic fatty acid synthase activity and adiponectin receptor 2, insulin receptor and acetyl-CoA carboxylase mRNA levels (p<0.05). Plasma insulin had a decreasing tendency in the niacin treatment group compared with control (p = 0.067). Plasma very low density lipoproteins, leptin levels and the hepatic adiponectin receptor 1 and carnitine palmitoyl transferase 1 genes expression were not significantly altered with niacin addition to the diet (p>0.05). However, niacin treatment significantly inhibited the hepatocytes lipid accumulation compared with the control group (p<0.05). In conclusion, niacin treatment can decrease hepatic fatty acids synthesis, but does not alter fatty acids oxidation and triacylglycerol export. And this whole process attenuates lipid accumulation in liver. Besides, the hormones of insulin, leptin and adiponectin are associated with the regulation of niacin in hepatic lipid metabolism in rabbits.

• Preventive Nutrition and Food Science
• /
• v.7 no.2
• /
• pp.113-118
• /
• 2002

Alpha-lipoic acid is a known hypoglycemic agent that may be useful in the treatment of diabetes. The objective of this study was to investigate the fate of glucose in isolated muscles incubated with lipoic acid by determining its direct effects on specific metabolic and signaling pathways. Soleus muscles from healthy rats were incubated with lipoic acid in the absence or presence of insulin. Glucose transport, glycogen synthesis, glucose oxidation and lipid synthesis were determined and affects on major pathways associated with insulin signaling were evaluated. Glucose transport was not significantly altered by the addition of lipoic acid to the incubation medium. However, lipoic acid decreased glycogen synthesis in comparison to controls. Glucose oxidation was moderately increased while de-novo lipid synthesis from glucose was inhibited. Wortmannin repressed insulin stimulation of glucose incorporation into glycogen, an effect that was augmented by the combined treatment of wortmannin and lipoic acid. Basal and insulin-stimulated serine phosphorylation of Akt was not changed by the addition of lipoic acid to the incubation medium. These data show that in this in vitro model, lipoic acid did not significantly affect glucose uptake but dramatically modified pathways of glucose metabolism within muscle tissue.

• Animal Bioscience
• /
• v.35 no.2
• /
• pp.166-176
• /
• 2022

Objective: Sperm is particularly susceptible to reactive oxygen species (ROS) stress. Glutathione (GSH) is an endogenous antioxidant that regulates sperm redox homeostasis. However, it is not clear whether boar sperm could utilize cysteine for synthesis GSH to protect sperm quality from ROS damage. Therefore, the present study was undertaken to elucidate the mechanism of how cysteine is involved in protecting boar sperm quality during liquid storage. Methods: Sperm motility, membrane integrity, lipid peroxidation, 4-hydroxyIlonenal (4-HNE) modifications, mitochondrial membrane potential, as well as the levels of ROS, GSH, and, ATP were evaluated. Moreover, the enzymes (GCLC: glutamate cysteine ligase; GSS: glutathione synthetase) that are involved in glutathione synthesis from cysteine precursor were detected by western blotting. Results: Compared to the control, addition of 1.25 mM cysteine to the liquid storage significantly increased boar sperm progressive motility, straight-line velocity, curvilinear velocity, beat-cross frequency, membrane integrity, mitochondrial membrane potential, ATP level, acrosome integrity, activities of superoxide dismutase and catalase, and GSH level, while reducing the ROS level, lipid peroxidation and 4-HNE modifications. It was also observed that the GCLC and GSS were expressed in boar sperm. Interestingly, when we used menadione to induce sperm with ROS stress, the menadione associated damages were observed to be reduced by the cysteine supplementation. Moreover, compared to the cysteine treatment, the γ-glutamylcysteine synthetase (γ-GCS) activity, GSH level, mitochondrial membrane potential, ATP level, membrane integrity and progressive motility in boar sperm were decreased by supplementing with an inhibitor of GSH synthesis, buthionine sulfoximine. Conclusion: These data suggest that boar sperm could biosynthesize the GSH from cysteine in vitro. Therefore, during storage, addition of cysteine improves boar sperm quality via enhancing the GSH synthesis to resist ROS stress.

• Journal of Nutrition and Health
• /
• v.27 no.9
• /
• pp.910-923
• /
• 1994

The effects of individual fatty acids, differing in their degree of unsaturation(18:0, 18:1, 18:2 and 18:3) on the biosynthesis and secretion and lipids were investigated in Hep-G2 cells. Synthesis of apolipoprotein was measured by the incorporation of 3H-leucine into apolipoprotein(d<1.21g/ml) and synthesis of lipids was measured by the incorporation of 3H-glycerol and 14C-acetate into various lipid classes. Inclusion of 1.0mM of each fatty acids into the culture medium significantly increased the synthesis of total apolipoprotein and Apo B(p<0.05). However, addition of fatty acid did not affect the synthesis of cellular and medium protein. Among different fatty acids tested, oleic acid had the greatest effect on Apo B synthesis. While stearic, linoleic and linolenic acid, all had similar effects. The secretion of triglyceride into the medium markedly increased in all fatty acid groups being 5-6 times over the albumin control. The triglyceride secretion was the highest int he oleic acid group. The secretion of phospholipid and cholesterol also increased with triglyceride output. A positive relationship existed between the output of lipoprotein-triglyceride and Apo B. Since the synthesis of Apo B was significantly increased when various fatty acids were included into the culture medium, part of the apparently stimulated synthesis of the apolipoprotein may be in response to the increased formation and secretion of lipoprotein lipids.

• Biomolecules & Therapeutics
• /
• v.9 no.3
• /
• pp.176-182
• /
• 2001

Some pharmacological activities of acanthoic acid, isolated from Acanthopanax koreanum root was investigated in animals. It is revealed that the compound had analgesic and anti-inflammatory activities without actions on central nervous system and showed inhibition of lipid peroxidation. The anti-inflammatory activity might be related to inhibition of prostaglandin E$_2$ synthesis in exudates of inflammation.

• Journal of Ginseng Research
• /
• v.47 no.4
• /
• pp.524-533
• /
• 2023

Background: Obesity is a risk factor for aging and many diseases, and the disorder of lipid metabolism makes it prominent. This study aims to investigate the effect of ginsenoside Rg1 on aging, lipid metabolism and stress resistance Methods: Rg1 was administered to Caenorhabditis elegans (C. elegans) cultured in NGM or GNGM. The lifespan, locomotory activity, lipid accumulation, cold and heat stress resistance and related mRNA expression of the worms were examined. Gene knockout mutants were used to clarify the effect on lipid metabolism of Rg1. GFP-binding mutants were used to observe the changes in protein expression Results: We reported that Rg1 reduced lipid accumulation and improved stress resistance in C. elegans. Rg1 significantly reduced the expression of fatty acid synthesis-related genes and lipid metabolism-related genes in C. elegans. However, Rg1 did not affect the fat storage in fat-5/fat-6 double mutant or nhr-49 mutant. Combined with network pharmacology, we clarified the possible pathways and targets of Rg1 in lipid metabolism. In addition, Rg1-treated C. elegans showed a higher expression of anti-oxidative genes and heat shock proteins, which might contribute to stress resistance Conclusion: Rg1 reduced fat accumulation by regulating lipid metabolism via nhr-49 and enhanced stress resistance by its antioxidant effect in C. elegans.