scholarly journals Effect of lovastatin on acyl-CoA: cholesterol O-acyltransferase (ACAT) activity and the basolateral-membrane secretion of newly synthesized lipids by CaCo-2 cells

1990 ◽  
Vol 272 (2) ◽  
pp. 427-433 ◽  
Author(s):  
N T Kam ◽  
E Albright ◽  
S Mathur ◽  
F J Field
Keyword(s):  
Cholesterol Synthesis ◽  
Cholesterol Metabolism ◽  
Reductase Activity ◽  
Basolateral Membrane ◽  
Fatty Acyl ◽  
Intestinal Cell ◽  
Intact Cells ◽  
Hmg Coa Reductase ◽  
Acat Activity ◽  
Coa Reductase

Lovastatin, a potent competitive inhibitor of 3-hydroxy-3-methylglutaryl-CoA (HMG-CoA) reductase activity, was used to study the regulation of cholesterol metabolism and the basolateral-membrane secretion of triacylglycerol and cholesterol in the human intestinal cell line CaCo-2. At 0.1 microgram/ml, lovastatin decreased 3H2O incorporation into cholesterol by 71%. In membranes prepared from cells incubated with lovastatin for 18 h, HMG-CoA reductase activity was induced 4-8-fold. Mevalonolactone prevented this induction. In intact cells, lovastatin (10 micrograms/ml) decreased cholesterol esterification by 50%. The reductase inhibitor decreased membrane acyl-CoA:cholesterol O-acyltransferase (ACAT) activity by 50% at 5 micrograms/ml. ACAT inhibition by lavastatin was not reversed by adding excess of cholesterol or fatty acyl-CoA to the assay. Lovastatin, in the presence or absence of mevalonolactone, decreased the basolateral secretion of newly synthesized cholesteryl esters and triacylglycerols. Lovastatin also inhibited the esterification of absorbed cholesterol and the secretion of this newly synthesized cholesteryl ester. Lovastatin is a potent inhibitor of cholesterol synthesis in CaCo-2 cells. Moreover, it is a direct inhibitor of ACAT activity, independently of its effect on HMG-CoA reductase and cholesterol synthesis.

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.

Effect of glucose or fructose feeding on cholesterol synthesis in diabetic animals

1985 ◽  
Vol 249 (5) ◽  
pp. G634-G641 ◽  
Author(s):  
K. R. Feingold ◽  
A. H. Moser
Keyword(s):  
Cholesterol Synthesis ◽  
Reductase Activity ◽  
Active Form ◽  
Diabetic Rats ◽  
Hepatic Cholesterol ◽  
Hmg Coa Reductase ◽  
Hepatic Cholesterol Synthesis ◽  
Streptozotocin Induced Diabetes ◽  
Intestinal Hypertrophy ◽  
Coa Reductase

Previous studies have demonstrated that cholesterol synthesis is increased twofold in the small intestines of rats with streptozotocin-induced diabetes. The purpose of the present study was to determine the effect of adding glucose or fructose to standard rat chow on cholesterol synthesis in control and diabetic rats. In control rats a 25% glucose or fructose diet fed for 21 days markedly inhibited hepatic cholesterol synthesis in the liver. In contrast, in diabetic animals only fructose inhibited hepatic cholesterol synthesis. In both control and diabetic animals the addition of these simple sugars to the diet did not markedly alter extrahepatic cholesterol synthesis. The enhancement of small intestinal cholesterol synthesis observed in diabetic animals was present regardless of the dietary manipulations. Further studies demonstrated that the addition of smaller concentrations of fructose (10%) to standard rat chow decreased hepatic cholesterol synthesis in both control and diabetic rats. Similarly the addition of fructose to the diet of control and diabetics for a period as short as 2 days was also sufficient to inhibit hepatic cholesterol synthesis. In both control and diabetic animals, fructose feeding decreased hepatic 3-hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) reductase activity but did not alter the percentage of HMG-CoA reductase in the active form. Finally, the intestinal hypertrophy and stimulation of intestinal cholesterogenesis that are characteristic of streptozotocin-induced diabetes occurred when either glucose or fructose was the sole caloric source.

scholarly journals Inhibition of HMG-CoA Reductase Activity from Active Compounds of Ginger (Zingiber officinale): In-Silico Study

2021 ◽  
Vol 1 (1) ◽  
pp. 32-38
Author(s):  
Rosario Trijuliamos Manalu ◽  
Imelia Omega Meheda ◽  
Cintya Octaviani
Keyword(s):  
In Silico ◽  
Cholesterol Metabolism ◽  
Raw Materials ◽  
Reductase Activity ◽  
Zingiber Officinale ◽  
Active Compounds ◽  
Hmg Coa Reductase ◽  
Conducting Research ◽  
Main Components ◽  
Coa Reductase

ABSTRAK   Koleterol merupakan salah satu dari lemak tubuh dalam asam lemak bebas dan ester, yang termasuk komponen utama selaput sel otak dan saraf. Namun, tidak jarang kolesterol menjadi penyebab penyakit terutama penyakit jantung yang terus meningkat setiap tahunnya di Indonesia. Sehingga perlu strategi pengobatan yang efektif dan aman dengan melakukan penelitian tanaman Indonesia sebagai upaya kemandirian bahan baku obat. Tujuan dari penelitian ini adalah untuk menentukan aktivitas penghambatan dari senyawa aktif tanaman Jahe pada HMG-KoA reduktase secara in-silico melalui penambatan molekul. Senyawa aktif yang digunakan dalam penelitian ini curcumin, capsaisin, gingerol, paradol, shogaol dilakukan docking molekuler menggunakan software PLANTS dengan tujuan untuk mengetahui score docking dan interaksi kelima senyawa terhadap enzim HMG-KoA reduktase yang berperan terhadap metabolism lemak/kolesterol. Senyawa pembanding yang digunakan adalah simvastatin dan atorvastatin yang merupakan obat lini pertama untuk pengobatan displipidemia. Hasil score docking menunjukkan bahwa kelima senyawa aktif yang digunakan sebagai ligan, menunjukkan score docking yang lebih rendah dibandingkan dengan ligan pembanding, sehingga kelima senyawa aktif ini mampu untuk menghambat biosintesis kolesterol atau kandidat obat baru pengganti simvastatin dan atorvastatin serta berpotensi sebagai dyslipidemia.   ABSTRACT Cholesterol is one of the body's fats in free fatty acids and esters, which are the main components of brain and nerve cell membranes. However, it is not uncommon for cholesterol to be the cause of disease, especially heart disease, which continues to increase every year in Indonesia. So it needs an effective and safe treatment strategy by conducting research on Indonesian plants as an effort to be independent of medicinal raw materials. The aim of this study was to determine the inhibitory activity of the active compound of Ginger plant on HMG-CoA reductase in-silico through molecular anchoring. The active compounds used in this study were curcumin, capsaicin, gingerol, paradol, shogaol. Molecular docking was carried out using PLANTS software with the aim of knowing the docking score and the interaction of the five compounds with the HMG-CoA reductase enzyme that plays a role in fat/cholesterol metabolism. Comparative compounds used are simvastatin and atorvastatin which are first-line drugs for the treatment of dysplipidemia.  

scholarly journals Regulation of cholesterol synthesis in the liver and mammary gland of the lactating rat

1983 ◽  
Vol 212 (3) ◽  
pp. 843-848 ◽  
Author(s):  
G F Gibbons ◽  
C R Pullinger ◽  
M R Munday ◽  
D H Williamson
Keyword(s):  
Mammary Gland ◽  
Inverse Relationship ◽  
Cholesterol Synthesis ◽  
Reductase Activity ◽  
Significant Decline ◽  
High Fat ◽  
Hmg Coa Reductase ◽  
Lactating Mammary Gland ◽  
Coa Reductase

The activity of 3-hydroxy-3-methylglutaryl-CoA reductase (HMG-CoA reductase; EC 1.1.1.34) in the lactating mammary gland of rats killed between 10:00 and 14:30 h was 2-3 times that in the livers of the same animals. In contrast, after injection of 3H2O in vivo, the rate of appearance of 3H in the cholesterol of the gland was much lower than that in the liver. In the mammary gland of virgin and non-lactating animals, the activity of HMG-CoA reductase was less than 10% of that of the lactating gland. The activity of HMG-CoA reductase in the lactating mammary gland was significantly (P less than 0.005) lower at midnight than at mid-day, and appeared to show an inverse relationship to the activity of the liver enzyme. However, there was no corresponding change in the incorporation of 3H into the gland cholesterol. Withdrawal of food for 6h had no effect on the activity of HMG-CoA reductase in the lactating mammary gland, but resulted in a significant decrease (P less than 0.005) in that of the liver. Starvation of lactating rats for 24h produced a significant decrease (P less than 0.005) in the activity of the enzyme in both organs. There was also a significant decline in the rate at which 3H2O was incorporated in vivo into the cholesterol of both organs (liver, P less than 0.05; gland, P less than 0.005). Giving a high-fat palatable diet together with chow to lactating animals led to a decline in HMG-CoA reductase activity in the mammary gland, but not in liver. This decrease in the gland was not accompanied by a corresponding decline in the apparent rate of cholesterol synthesis.

Assay of HMG-CoA reductase activity in the evaluation of cholesterol synthesis in man

1989 ◽  
Vol 183 (1) ◽  
pp. 77-81 ◽  
Author(s):  
Nicola Carulli ◽  
Alberto Tripodi ◽  
Carubbi Francesca
Keyword(s):  
Cholesterol Synthesis ◽  
Reductase Activity ◽  
Hmg Coa Reductase ◽  
Coa Reductase
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