• Animal Bioscience
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• v.35 no.5
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• pp.763-777
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• 2022

Objective: Excessive lipid accumulation in adipocytes results in prevalence of obesity and metabolic syndrome. Curcumin (CUR), a naturally phenolic active ingredient, has been shown to have lipid-lowering effects. However, its underlying mechanisms have remained largely unknown. Therefore, the study aims to determine the effect of CUR on cellular lipid accumulation in porcine subcutaneous preadipocytes (PSPA) and to clarify novel mechanisms. Methods: The PSPA were cultured and treated with or without CUR. Both cell counting Kit-8 and lactate dehydrogenase release assays were used to examine cytotoxicity. Intracellular lipid contents were measured by oil-red-o staining extraction and triglyceride quantification. Apoptosis was determined by flow cytometry and the terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate-nick end labelling assay. Adipogenic and apoptosis genes were analyzed by quantitative polymerase chain reaction and Western blot. Results: The CUR dose-dependently reduced the proliferation and lipid accumulation of PSPA. Noncytotoxic doses of CUR (10 to 20 μM) significantly inhibited extracellular signal-regulated kinase 1/2 (ERK1/2) phosphorylation and expression of adipogenic genes peroxisome proliferation-activity receptor-γ (PPAR-γ), CCAAT/enhancer binding protein-α, sterol regulatory element-binding protein-1c, adipocyte protein-2, glucose transporter-4 as well as key lipogenic enzymes fatty acid synthase and acetyl-CoA carboxylase, while ERK1/2 activation significantly reversed CUR-reduced lipid accumulation by increasing PPAR-γ. Furthermore, compared with differentiation induced media treated cells, higher dose of CUR (30 μM) significantly decreased the expression of AKT and B-cell lymphoma-2 (BCL-2), while increased the expression of BCL-2-associated X (BAX) and the BAX/BCL-2 expression ratio, suggesting triggered apoptosis by inactivating AKT and increasing BAX/BCL-2 ratio and Caspase-3 expression. Moreover, AKT activation significantly rescued CUR inhibiting lipid accumulation via repressing apoptosis. Conclusion: These results demonstrate that CUR is capable of suppressing differentiation by inhibiting ERK1/2-PPAR-γ signaling pathway and triggering apoptosis via decreasing AKT and subsequently increasing BAX/BCL-2 ratio and Caspase-3, suggesting that CUR provides an important method for the reduction of porcine body fat, as well as the prevention and treatment of human obesity.

• Journal of Korean Medicine for Obesity Research
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• v.24 no.1
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• pp.1-12
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• 2024

Objectives: Ephedrae herba (EH) and Coicis semen (CS) has been frequently prescribed for the treatment of obesity. However, effects of combinational extracts of these two herbs on non-alcoholic fatty liver disease are unknown. The aim of the present study was to investigate the effects of EH and CS on lipid accumulation and glucose absorption in free fatty acids (FFAs) or palmitic acid (PA)-treated HepG2 cells. Methods: Five samples of EH and CS were extracted by combination ratios (S1=0:100, S2=25:75, S3=50:50, S4=75:25, S5=100:0). Oil Red O staining was used to measure lipid accumulation in FFAs-induced steatosis cells. Intracellular triglycerides and total cholesterol levels were measured in FFAs-induced steatotic HepG2 cells. In PA-treated cells, intracellular 2-NBDG was detected using a fluorescence microplate reader and flow cytometry. Phosphorylation of key metabolism-related factors of AMP-activated protein kinase and acetyl-CoA carboxylase, expression of key lipid synthesis-related factors carnitine palmitoyltransferase 1 alpha (CPT1α), sterol regulatory element-binding protein 1 (SREBP1), peroxisome proliferator-activated receptor gamma (PPARγ) and CCAAT enhancer binding protein alpha (C/EBPα) were confirmed by western blot. Results: Treatment of EH-CS combination in the FFAs-induced steatotic HepG2 cells significantly reduced lipid accumulation. As the relative ratio of Ephedrae herba increased, the lipid-lowering effects of the combination were increased. However, S1 and S5 of Ephedrae herba and Coicis semen did not significantly reduce triglycerides and total cholesterol induced by FFAs. However, the combination of Ephedrae herba and Coicis semen restored glucose absorption in PA-induced HepG2 cells. Major makers of SREBP1, PPARγ, C/EBPα, and CPT1α expression tended to decrease with EH ratio. Conclusions: The EH-CS combination has advantages over sole EH and CS extracts in improving lipid and glucose metabolism in liver steatosis models.

• Journal of Nutrition and Health
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• v.30 no.8
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• pp.930-935
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• 1997

Fatty acid binging proteins(FABP) are distinct but related gene productes which are found in many mamalian cell types. FABP bind long chain fatty acids in vitro. However, their functions and mechanisms of action, in vivo, remain unknown . Also not known is whether all FABP function similaryly in their respective cell types. or whether different FABP have unique functions. The puropose of the present study was to assess whether different members of the FABP family exhibit different structural and function properties. A comparison was made between heart(H-FABP) and liver (L-FABP). The results show that the binding sites of both FABP are hydrophobic in nature, although the L-FABP site is more nonpolar than the H-FABP site. Additionally, the bound ligand experiences less motional constraint within the H-FABP binding site than within the L-FABP binding site. In accordance with these differences in structural properties, it was found that anthroyloxy-fatty acid transfer from H-FABP to membranes is markedly faster than from L-FABP. moreover, the mechanism of fatty acid transfer to phospholipid membranes appears to occur via transient collisional interactions between H-FABP and membranes. In contrast , transfer of fatty acid from L-FABP occurs via an aqueous diffusion mechanism.

• Korean Journal of Animal Reproduction
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• v.25 no.4
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• pp.317-325
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• 2001

This study investigated the effect of ferrous sulfate (Fe$^{2+}$) and/or ascorbic acid (Asc) on fertilizing ability in vitro of frozen-thawed boar spermatozoa. Using chlortetracycline (CTC) fluorescence, the spermatozoa was treated in preincubation medium with control, Fe$^{2+}$(1 mM), Asc (0.5 mM) and Fe$^{2+}$Asc to assessed for acrosome reaction, and the oocyte penetration test to determine whether the Fe$^{2+}$ and/or Asc can promote the penetration ability in vitro. When frozen-thawed spermatozoa was washed with preincubation medium, there were significantly (P ＜ 0.05) more acrosome-reacted in medium with Fe$^{2+}$Asc (38%) than control (27%). The penetration rates were also significantly (P ＜ 0.05) higher in medium with Fe$^{2+}$Asc (76%) than control (55%). Next, the lipid peroxidation of sperm was evaluated on the basis of malondialdehyde production following same treatments. The addition of Fe$^{2+}$Asc to sperm suspension increases the formation of malondialdehyde. However, there were not significantly different under the all conditions. The sperm suspension were also treated with control, Fe$^{2+}$, Asc and Fe$^{2+}$/Asc and assayed for sulfhydry1(-SH) group content. In the Fe$^{2+}$/Asc group, sperm-SH group were higher than another groups. In spermatozoa treated with Fe$^{2+}$ and/or Asc, however, no changes in sperm -SH-groups were detected when compared to controls. In another experiment, the activity of sperm binding to zona pellucida was evaluated through binding to salt-stored porcine oocytes. In control and Asc treatment groups, sperm binding to zona pellucida were significantly (P ＜ 0.05) higher than in medium with Fe$^{2+}$. On the other hand, there is not a significant increase in binding to zona pellucida with spermatozoa treated by Fe$^{2+}$/Asc. In summary, the present study suggests that Fe$^{2+}$/Asc causes an enhancement in fertilizing ability that is associated with penetration rate increased without change of spermatozoa binding capacity to homologous zona pellucida.o homologous zona pellucida.

• Journal of Microbiology
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• v.33 no.3
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• pp.228-233
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• 1995

As S. epidermidis cell was fractionated into cell wall, cell membrane, and cytoplasm, the cell membrane proved to be the most efficient absorbent for lead ion. Utrasonication was effective, when the cells were treated during their exponential growth. The amount of the lead ion adsorbed in cell membrane decreased as hydrogen ion concentration of solution increased. Protein purified from the cell membrane showed higher adsorption capacity for the lead ion than peptidoglycan, teichoic acid from cell wall, or cell membrane lipid. Modification of carboxyl groups in the membrane protein with ethylenediamine and 1-ethyl-3-carbodiimide hydrochloride resulted in a considerable decrease of lead ion adsorption capability, suggesting that the main binding site for lead ion was the carboxyl groups of protein in cell membrane.

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

• Bulletin of the Korean Chemical Society
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• v.35 no.3
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• pp.783-792
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• 2014

The binding interaction between a hemolytic peptide ${\delta}$-lysin and a zwitterionic lipid bilayer POPC was investigated through a series of molecular dynamics (MD) simulations. ${\delta}$-Lysin is a 26-residue, amphipathic, ${\alpha}$-helical peptide toxin secreted by Staphylococcus aureus. Unlike typical antimicrobial peptides, ${\delta}$-lysin has no net charge and it is often found in aggregated forms in solution even at low concentration. Our study showed that only the monomer, not dimer, inserts into the bilayer interior. The monomer is preferentially attracted toward the membrane with its hydrophilic side facing the bilayer surface. However, peptide insertion requires the opposite orientation where the hydrophobic side of peptide points toward the membrane interior. Such orientation allows the charged residues, Lys and Asp, to have stable salt bridges with the lipid head-group while the hydrophobic residues are buried deeper in the hydrophobic lipid interior. Our simulations suggest that breaking these salt bridges is the key step for the monomer to be fully inserted into the center of lipid bilayer and, possibly, to translocate across the membrane.

• Korean Journal of Food Science and Technology
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• v.46 no.4
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• pp.489-497
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• 2014

We examined the effects of unripe black raspberry water extract (UBR-W) on lipid metabolism and oxidative stress in mice. C57BL/6J mice were divided into 4 groups: those administered a control diet (CTL), high-fat diet (HFD), UBR-W and simvastatin for 12 weeks. In the HFD group, LDL cholesterol were significantly higher than in the CTL group. However, the UBR-W treated group showed dose-dependent reduction of plasma LDL levels. Hepatic total lipid, TC, and malondialdehyde were significantly increased in hyperlipidemic mice. However, supplementation with either UBR-W or simvastatin effectively reduced these lipid profiles and lipid peroxidation. UBR-W increased mRNA expression of the LDL receptor, sterol regulatory element binding protein 2 (SREBP2), 3-hydroxy-3-methylglutaryl (HMG)-CoA reductase and ATP-binding cassette transporter A1 (ABCA1) compared to that observed in the HFD group. In addition, UBR-W and simvastatin showed significantly reduced oxidized LDL uptake by the scavenger receptor CD36. These results suggest that UBR-W is useful for treatment and prevention of hyperlipidemia and lipid peroxidation.

• Journal of Microbiology
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• v.44 no.1
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• pp.98-105
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• 2006

Yersinia enterocolitica induces a broad range of gastrointestinal syndromes, including acute enteritis. We previously reported that the clinical isolate, Y. enterocolitica KU14, which lacks pYV, was still capable of causing clinical infection. The present study demonstrated that KU14 did not trigger the death of macrophages in vitro, unlike WA-314 (ATCC51871, which harbors the pYV virulence plasmid). However, the intracellular growth of KU14 in the macrophages was greater than that of WA-C (ATCC51872, a non-plasmid harboring the derivative pYV plasmid). Treatment with a cholesterol-binding drug $(\beta-cyclodextrin)$ that affected lipid rafts resulted in a dramatic reduction in the inracellular growth of KU14. These data clearly indicate that the enhanced inracellular growth of KU14 is related to lipid raft-mediated infection.

• The Korean Journal of Physiology and Pharmacology
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• v.2 no.5
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• pp.549-553
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• 1998

Using the planar lipid bilayer method, we investigated the effect of d-tubocurarine (dTC) on the extracellular side of large-conductance $Ca^{2+}-activated\;K^+$ channel from rat brain. When the initial open probability (Po) of the channel was relatively high, dTC decreased channel activity in a concentration dependent manner. In contrast, when the initial Po was lower, sub-micro molar dTC increased channel activity by destabilizing the closed states of the channel. Further addition of dTC up to micro molar range decreased channel activity. This dual effect of dTC implicates that there exist at least two different binding sites for dTC.