scholarly journals Antihyperlipidemic and Antioxidative Potentials of Onion (Allium cepaL.) Extract Fermented with a NovelLactobacillus caseiHD-010

2019 ◽  
Vol 2019 ◽  
pp. 1-10
Author(s):  
Woong-Suk Yang ◽  
Jin-Chul Kim ◽  
Jae Yong Lee ◽  
Cheorl-Ho Kim ◽  
Cher-Won Hwang
Keyword(s):  
Reductase Activity ◽  
Low Density Lipoprotein ◽  
Density Lipoprotein ◽  
Treated Group ◽  
Inhibitory Effect ◽  
Positive Control ◽  
Control Group ◽  
Hmg Coa Reductase ◽  
Onion Extract ◽  
Coa Reductase

The purpose of this study was to investigate antihyperlipidemic and antioxidative potentials of onion (Allium cepaL.) extract fermented with a novelLactobacillus caseiHD-010. In general, fermented onion extract is used for its antioxidative activity (ORAC), inhibitory effect on adipocytes differentiation, quercetin contents, and antihyperlipidemic activities. However, the effect of fermented onion extract on hyperlipidemia after oral administration using ApoE-deficient mice has not been reported yet. To understand the effect of fermented onion extract on hyperlipidemia, we used benzafibrate (10 mg/kg, bw/day) as a positive control in the present study. Serum was collected every week to analyze levels of low density lipoprotein (LDL), high density lipoprotein (HDL), triglyceride (TG), and cholesterol, 3-hydroxy-3-methylgutaryi-CoA (HMG-CoA) reductase activity, and cholesterol ester transport protein (CETP) activity. In the fermented onion-treated group, HDL level was significantly increased while levels of TG and LDL were significantly decreased compared to those in the control group. In addition, the inhibition activity of HMG-CoA reductase was increased 20% in the fermented onion-treated group at 100 mg/kg. CETP activity has been observed to be significantly inhibited in the fermented onion-treated groups compared to that in the control group. These results suggest that fermented onion has a preventive/therapeutic effect on hyperlipidemic disease. It might have potential to be developed as a functional food.

scholarly journals Effects of compactin, mevalonate and low-density lipoprotein on 3-hydroxy-3-methylglutaryl-coenzyme A reductase activity and low-density-lipoprotein-receptor activity in the human hepatoma cell line Hep G2

1984 ◽  
Vol 222 (1) ◽  
pp. 35-39 ◽  
Author(s):  
L H Cohen ◽  
M Griffioen ◽  
L Havekes ◽  
D Schouten ◽  
V van Hinsbergh ◽  
...  
Keyword(s):  
Reductase Activity ◽  
Hepatoma Cell ◽  
Low Density Lipoprotein ◽  
Density Lipoprotein ◽  
Hepatoma Cell Line ◽  
Low Density ◽  
Hep G2 ◽  
Human Hepatoma Cell ◽  
Hmg Coa Reductase ◽  
Coa Reductase

Compactin, an inhibitor of HMG-CoA (3-hydroxy-3-methylglutaryl-CoA) reductase, decreased cholesterol synthesis in intact Hep G2 cells. However, after the inhibitor was washed away, the HMG-CoA-reductase activity determined in the cell homogenate was found to be increased. Also the high-affinity association of LDL (low-density lipoprotein) to Hep G2 cells was elevated after incubation with compactin. Lipoprotein-depleted serum, present in the incubation medium, potentiated the compactin effect compared with incubation in the presence of human serum albumin. Addition of either mevalonate or LDL prevented the compactin-induced rise in activities of both HMG-CoA reductase and LDL receptor in a comparable manner. It is concluded that in this human hepatoma cell line, as in non-transformed cells, both endogenous mevalonate or mevalonate-derived products and exogenous cholesterol are able to modulate the HMG-CoA reductase activity as well as the LDL-receptor activity.

scholarly journals The Cholesterol-Lowering Effect of Alisol Acetates Based on HMG-CoA Reductase and Its Molecular Mechanism

2016 ◽  
Vol 2016 ◽  
pp. 1-11 ◽  
Author(s):  
Fei Xu ◽  
Hui Yu ◽  
Cai Lu ◽  
Jun Chen ◽  
Wei Gu
Keyword(s):  
Molecular Simulation ◽  
Reductase Activity ◽  
Low Density Lipoprotein ◽  
Density Lipoprotein ◽  
Lipoprotein Cholesterol ◽  
Hmg Coa Reductase ◽  
Coa Reductase ◽  
The Impact

This study measured the impact of alisol B 23-acetate and alisol A 24-acetate, the main active ingredients of the traditional Chinese medicine Alismatis rhizoma, on total cholesterol (TC), triglyceride (TG), high density lipoprotein-cholesterol (HDL-C), and low density lipoprotein-cholesterol (LDL-C) levels of hyperlipidemic mice. The binding of alisol B 23-acetate and alisol A 24-acetate to the key enzyme involved in the metabolism of TC, 3-hydroxy-3-methylglutary-coenzyme A (HMG-CoA) reductase, was studied using the reagent kit method and the western blotting technique combined with a molecular simulation technique. According to the results, alisol acetates significantly lower the TC, TG, and LDL-C concentrations of hyperlipidemic mice, while raising HDL-C concentrations. Alisol acetates lower HMG-CoA reductase activity in a dose-dependent fashion, both in vivo and in vitro. Neither of these alisol acetates significantly lower the protein expression of HMG-CoA. This suggests that alisol acetates lower the TC level via inhibiting the activity of HMG-CoA reductase by its prototype drug, which may exhibit an inhibition effect via directly and competitively binding to HMG-CoA. The side chain of the alisol acetate was the steering group via molecular simulation.

Regulation of low density lipoprotein receptor and 3-hydroxy-3-methyl-glutaryl-CoA reductase activities are differentially affected in Niemann–Pick type C and type D fibroblasts

1993 ◽  
Vol 71 (9-10) ◽  
pp. 467-474 ◽  
Author(s):  
Harkirat S. Sidhu ◽  
Stella A. R. Rastogi ◽  
David M. Byers ◽  
Duane L. Guernsey ◽  
Harold W. Cook ◽  
...  
Keyword(s):  
Reductase Activity ◽  
Low Density Lipoprotein ◽  
Density Lipoprotein ◽  
Cell Types ◽  
Low Density ◽  
Hmg Coa Reductase ◽  
Type D ◽  
Density Lipoprotein Receptor ◽  
Niemann Pick ◽  
Coa Reductase

Defective regulation of intracellular cholesterol metabolism has been investigated in cultured fibroblasts from two subtypes of Niemann–Pick type II disease: the panethnic Niemann–Pick type C (NPC) and the Nova Scotia type D (NPD). Cell extracts from NPC and NPD fibroblasts cultured in lipoprotein-deficient medium exhibited activities of 3-hydroxy-3-methylglutaryl-CoA (HMG-CoA) reductase that were two-fold greater than in normal cells. Addition of serum resulted in only a 15% decrease in HMG-CoA reductase activity within 6 h in these cells, compared with a decrease of 80% in normal fibroblasts. The initial rate of return to maximal values for the first 6 h after removal of serum was similar in all three cell types; thereafter, the rate was faster in the mutant fibroblasts. Binding and internalization of 125I-labeled low density lipoprotein (LDL) was not decreased within 12 h of incubation of NPC fibroblasts with serum, while a decrease of 50% was observed for both NPD and normal fibroblasts over this time period. Northern blot analysis also indicated a slower decrease in steady-state LDL receptor mRNA in NPC relative to normal and NPD cells. In all three cell types, inhibition of HMG-CoA reductase with mevinolin had no effect on serum-stimulated cholesterol esterification, while inhibition of acyl-CoA:cholesterol acyltransferase with Sandoz 58-035 did not influence HMG-CoA reductase activity, indicating that defects in these regulatory mechanisms are independent. Together with previous observations that NPC and NPD fibroblasts exhibit different levels of cholesterol accumulation and esterification, our results suggest that NPD may result from a distinct mutation in a Niemann–Pick type II gene, in which different mutations can differentially alter the various mechanisms of cholesterol regulation.Key words: Niemann–Pick disease, cholesterol regulation, low density lipoprotein receptor, 3-hydroxy-3-methylglutaryl-CoA reductase, acyl-CoA:cholesterol acyltransferase.

scholarly journals The regulation of 3-hydroxy-3-methylglutaryl-CoA reductase activity, cholesterol esterification and the expression of low-density lipoprotein receptors in cultured monocyte-derived macrophages

1983 ◽  
Vol 210 (2) ◽  
pp. 523-532 ◽  
Author(s):  
B L Knight ◽  
D D Patel ◽  
A K Soutar
Keyword(s):  
Reductase Activity ◽  
Low Density Lipoprotein ◽  
Density Lipoprotein ◽  
Low Density ◽  
Cholesteryl Esters ◽  
Acetate Incorporation ◽  
Normal Cells ◽  
Hmg Coa Reductase ◽  
Ldl Receptors ◽  
Coa Reductase

Human blood monocytes cultured in medium containing 20% whole serum showed the greatest activity of 3-hydroxy-3-methylglutaryl-CoA (HMG-CoA) reductase and [14C]acetate incorporation into non-saponifiable lipids around the 7th day after seeding, the period of greatest growth. Although there was enough low-density lipoprotein (LDL) in the medium to saturate the LDL receptors that were expressed by normal cells at that time, HMG-CoA reductase activity and acetate incorporation were as high in normal cells as in cells from familial-hypercholesterolaemic (FH) patients. Both the addition of extra LDL, which interacted with the cells by non-saturable processes, and receptor-mediated uptake of acetylated LDL significantly reduced reductase activity and increased incorporation of [14C]oleate into cholesteryl esters in normal cells and cells from FH patients (‘FH cells’), and reduced the expression of LDL receptors in normal cells. Pre-incubation for 20h in lipoprotein-deficient medium apparently increased the number of LDL receptors expressed by normal cells but reduced the activity of HMG-CoA reductase in both normal and FH cells. During subsequent incubations the same rate of degradation of acetylated LDL and of non-saturable degradation of LDL by FH cells was associated with the same reduction in HMG-CoA reductase activity, although LDL produced a much smaller stimulation of oleate incorporation into cholesteryl esters. In normal cells pre-incubated without lipoproteins, receptor-mediated uptake of LDL could abolish reductase activity and the expression of LDL receptors. The results suggested that in these cells, receptor-mediated uptake of LDL might have a greater effect on reductase activity and LDL receptors than the equivalent uptake of acetylated LDL. It is proposed that endogenous synthesis is an important source of cholesterol for growth of normal cells, and that the site at which cholesterol is deposited in the cells may determine the nature and extent of the metabolic events that follow.

Glycation and HMG-CoA Reductase Inhibitors: Implication in Diabetes and Associated Complications

2019 ◽  
Vol 15 (3) ◽  
pp. 213-223 ◽  
Author(s):  
Rabia Nabi ◽  
Sahir Sultan Alvi ◽  
Mohd. Saeed ◽  
Saheem Ahmad ◽  
Mohammad Salman Khan
Keyword(s):  
Oxidized Ldl ◽  
Advanced Glycation Endproducts ◽  
Low Density Lipoprotein ◽  
Ldl Receptor ◽  
Density Lipoprotein ◽  
Protective Role ◽  
Therapeutic Effects ◽  
Hmg Coa Reductase ◽  
Toxicological Effects ◽  
Coa Reductase

Introduction: Diabetes Mellitus (DM) acts as an absolute mediator of cardiovascular risk, prompting the prolonged occurrence, size and intricacy of atherosclerotic plaques via enhanced Advanced Glycation Endproducts (AGEs) formation. Moreover, hyperglycemia is associated with enhanced glyco-oxidized and oxidized Low-Density Lipoprotein (LDL) possessing greater atherogenicity and decreased the ability to regulate HMG-CoA reductase (HMG-R). Although aminoguanidine (AG) prevents the AGE-induced protein cross-linking due to its anti-glycation potential, it exerts several unusual pharmaco-toxicological effects thus restraining its desirable therapeutic effects. HMG-R inhibitors/statins exhibit a variety of beneficial impacts in addition to the cholesterol-lowering effects. Objective: Inhibition of AGEs interaction with receptor for AGEs (RAGE) and glyco-oxidized-LDL by HMG-R inhibitors could decrease LDL uptake by LDL-receptor (LDL-R), regulate cholesterol synthesis via HMG-R, decrease oxidative and inflammatory stress to improve the diabetes-associated complications. Conclusion: Current article appraises the pathological AGE-RAGE concerns in diabetes and its associated complications, mainly focusing on the phenomenon of both circulatory AGEs and those accumulating in tissues in diabetic nephropathy, diabetic neuropathy, and diabetic retinopathy, discussing the potential protective role of HMG-R inhibitors against diabetic complications.

scholarly journals The absolute rate of cholesterol biosynthesis in monocyte-macrophages from normal and familial hypercholesterolaemic subjects

1984 ◽  
Vol 219 (2) ◽  
pp. 461-470 ◽  
Author(s):  
D D Patel ◽  
C R Pullinger ◽  
B L Knight
Keyword(s):  
Cholesterol Synthesis ◽  
Reductase Activity ◽  
Cholesterol Biosynthesis ◽  
Specific Radioactivity ◽  
Density Lipoprotein ◽  
Cellular Protein ◽  
True Rate ◽  
Hmg Coa Reductase ◽  
Coa Reductase ◽  
In Cells

The true rate of cholesterogenesis in cultured monocyte-macrophages was determined from the incorporation of [2-14C]acetate into cholesterol, using the desmosterol (cholesta-5,24-dien-3 beta-ol) that accumulated in the presence of the drug triparanol to estimate the specific radioactivity of the newly formed sterols. It was shown that this procedure could be successfully adapted for use with cultured monocytes despite the accumulation of other unidentified biosynthetic intermediates. In cells maintained in 20% (v/v) whole serum approx. 25% of the sterol carbon was derived from exogenous acetate. Cholesterol synthesis was as high in normal cells as in cells from homozygous familial hypercholesterolaemic (FH) subjects and accounted for 50% of the increase in cellular cholesterol. The addition of extra low-density lipoprotein (LDL) reduced cholesterol synthesis, apparently through a decrease in the activity of 3-hydroxy-3-methylglutaryl-CoA reductase (HMG-CoA reductase). When incubated in lipoprotein-deficient serum some cells did not survive, but those that remained showed a normal increase in protein content; the amount of cellular protein and cholesterol in each well did not increase and cholesterol synthesis was reduced by over 80%. HMG-CoA reductase activity fell less dramatically and the proportion of sterol carbon derived from exogenous acetate increased, suggesting that the low rate of cholesterogenesis with lipoprotein-deficient serum was due to a shortage of substrate. The results indicate that under normal conditions monocyte-macrophages obtain cholesterol from endogenous synthesis rather than through receptor-mediated uptake of LDL, and that synthesis together with non-saturable uptake of LDL provides the majority of the cholesterol required to support growth.

scholarly journals Study the Effects of Methotrexate with and without Vitamin A on Some Biochemical and Histological Parameters in Male Rabbits

2017 ◽  
Vol 11 (1) ◽  
pp. 45-53
Author(s):  
Makarim Q. Al-Lami ◽  
Asmaa I. Sail ◽  
Salah M. Al-Chalabi ◽  
Ferial A. Al-Mahdawi
Keyword(s):  
Vitamin A ◽  
Histological Examination ◽  
Low Density Lipoprotein ◽  
Density Lipoprotein ◽  
Treated Group ◽  
Control Group ◽  
Low Density ◽  
Typical Structure ◽  
Histological Changes ◽  
Sinusoidal Dilatation

The present study aims to evaluate the effects of methotrexate (MTX) with and without vitamin A (Vit. A) on some biochemical parameters and histological structure in male rabbits liver. Twenty male rabbits weighing 1250-1480 gm were divided into four equal number groups. The first group was given 2 ml distilled water as control group. The second group was given MTX (20 mg/kg), the third group was given Vit. A (5000 IU), while the fourth group was given MTX (20 mg/kg) +Vit. A (5000 IU) in alternative days. Following four weeks of treatment, lipid profile total cholesterol (TC), triglycerides (TG), high-density lipoprotein (HDL), [low-density lipoprotein (LDL) and very low-density lipoprotein (VLDL)]; in addition to thyroid hormones triiodothyronine (T3) and thyroxin (T4)] and liver enzymes [glutamic pyruvic transaminase (GPT) and glutamic oxaloacetic transaminase (GOT)] were determined in the serum. Also, the histological examination of liver of all the experimental groups were carried out. The results were revealed that the treatment with MTX caused a significant P≤0.05 increases in TC, HDL, LDL, T4, and GPT when compared with the control group. The treatment with Vit. A did not cause any significant P≥0.05 differences in all the studied parameters. The MTX+Vit. A treated group showed a significant P≤0.05 increases only in GPT compared with the control group; while a significant P≤0.05 decreases was found in TC, HDL, T3, T4, and GOT when compared with the MTX treated group. The histological examination of the liver sections showed that MTX administration caused major histological changes in comparison with the control such as inflammatory cell infiltrations, vascular congestion, sinusoidal dilatation and granular degeneration of hepatocytes. Treatment with Vit. A showed a typical structure in liver tissue. While in MTX+Vit. A group, the histological changes were less severe than those in the MTX treated group; these changes were granular degeneration of hepatocytes and sinusoidal dilatation at low levels. The overall results of this study confirmed that administration of Vit. A decreased the side effects of MTX; this protective effect of Vit. A may have clinical applications in chemotherapy.

scholarly journals The effect of (−)-hydroxycitrate on the activity of the low-density-lipoprotein receptor and 3-hydroxy-3-methylglutaryl-CoA reductase levels in the human hepatoma cell line Hep G2

1990 ◽  
Vol 272 (1) ◽  
pp. 181-186 ◽  
Author(s):  
T A Berkhout ◽  
L M Havekes ◽  
N J Pearce ◽  
P H E Groot
Keyword(s):  
Low Density Lipoprotein ◽  
Ldl Receptor ◽  
Density Lipoprotein ◽  
Low Density ◽  
Hep G2 ◽  
Atp Citrate Lyase ◽  
Hmg Coa Reductase ◽  
Synthetic Pathway ◽  
Citrate Lyase ◽  
Coa Reductase

(-)-Hydroxycitrate, a potent inhibitor of ATP citrate-lyase, was tested in Hep G2 cells for effects on cholesterol homoeostasis. After 2.5 h and 18 h incubations with (-)-hydroxycitrate at concentrations of 0.5 mM or higher, incorporation of [1,5-14C]citrate into fatty acids and cholesterol was strongly inhibited. This most likely reflects an effective inhibition of ATP citrate-lyase. Cholesterol biosynthesis was decreased to 27% of the control value as measured by incorporations from 3H2O, indicating a decreased flux of carbon units through the cholesterol-synthetic pathway. After 18 h preincubation with 2 mM-(-)-hydroxycitrate, the cellular low-density-lipoprotein (LDL) receptor activity was increased by 50%, as determined by the receptor-mediated association and degradation. Measurements of receptor-mediated binding versus LDL concentration suggests that this increase was due to an increase in the numbers of LDL receptors. Simultaneously, enzyme levels of 3-hydroxy-3-methylglutaryl-CoA (HMG-CoA) reductase as determined by activity measurements increased 30-fold. Our results suggest that the increases in HMG-CoA reductase and the LDL receptor are initiated by the decreased flux of carbon units in the cholesterol-synthetic pathway, owing to inhibition of ATP citratelyase. A similar induction of HMG-CoA reductase and LDL receptor was also found after preincubations of cells with 0.3 microM-mevinolin, suggesting that the underlying mechanism for this induction is identical for both drugs.

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