• Journal of the Korean Society of Food Science and Nutrition
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• v.28 no.4
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• pp.958-962
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• 1999

Hydroxy methylglutaryl CoA(HMG CoA) reductase and acyl CoA:cholesterol acyltransferase(ACAT) are two important enzymes that are associated with regulation of cholesterol metabolism. The inhibitors of HMG CoA reductase and ACAT are very effective in lowering serum cholesterol in most animal species. In present study, various plant extracts with hot water were used to examine the inhibitory activities against HMG CoA reductase and ACAT that are involved in cholesterol biosynthesis and cholesterol esterification in tissues, respectively. The extracts of Fagophyrum rotundatum, Rosa multiflora, Rosa rugosa and Alisma orientalis exhibited significant inhibitory activities against the ACAT, 29%, 24%, 19%, and 18%, respectively. However the extracts of Typha augustifolia, Polygonum cuspidatum, Crataegus pinnatifida, Polygonum multiflorum inhibited the HMG CoA reductase activity by 53%, 42%, 37%, and 33% respectively. Results suggest that these plant extracts might play important roles in the regulation of the cholesterol metabolism in vivo.

• Journal of Ginseng Research
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• v.19 no.3
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• pp.212-218
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• 1995

A human hepatoma cell line, hep G2, was used to investigate the mechanism of serum cholesterol reduction by ginseng total saponin, ginsenoside-$Rb_1$, - $Rb_2$, and non-saponin fraction (ether extraction). Hep G2 cells were incubated in 10 $\mu\textrm{g}$/ml of cholesterol containing serum free-RPMl1640 medium with various concentration of ginseng components. The amounts of cholesterol in Hep G2 cells were decreased to maximum 51% in total saponin or two ginsenoside-treated groups while there was 137% increase in cholesterol level of control group as compared with that of normal group. Nonsaponin groups did not show the same effect. In order to elucidate the observed changes in the amount of cholesterol, the activity of amyl CoA : cholesterol acyltransferase (ACAT) in groups showing remarkable reduction in cholesterol amount, i.e., total saponin 10-6%, ginsenoside-$Rb_1$ $10^{-4}$%, ginsenoside-$Rb_2$, $10^{-4}$%, and non-saponin fraction $10^{-4}$%, was assayed using [1-$^{-14}C$%]oleic acid as enzyme substrate. The activity of ACAT was increased in all groups tested as compared with that of control group except for non-saponin group cultured in water soluble cholesterol containing medium. The serum cholesterol lowering effects of ginseng components can partially be attributed to the increased hepatocellular ACAT activity.

• Proceedings of the Korean Society of Applied Pharmacology
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• 1995.04a
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• pp.67-67
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• 1995

Acyl-CoA:cholesterol acyltransferase (ACAT, EC 2.3.1.26) plays an important role in the control of intracellular free cholesterol content via its cholesterol esterifying activity. ACAT inhibitors are expected to be effective for treatment of atherosclerosis and hypercholesterolemia. In the course of a screening program for ACAT inhibitors from microbial sources, GERI-BP001 M, A, and B were isolated from the fermentation broth of a fungal strain. GERI-BP001 compounds were isolated from a culture broth of Aspergillus fumigatus F37 by acetone extraction, EtOAc extraction, SiO$_2$ column chromatography, and reverse phase HPLC. The structure of GERI-BP001 coumpounds were determined by $^1$H-NMR, $\^$l3/C-NMR, 2D-NMR, NOESY, and long range C-H COSY experiments. GERI-BP001 M, A, and B inhibit ACAT activity in an enzyme assay system using rat liver microsomes by 50% at concentrations of 75, 147, and 71 ${\mu}$M, respectively.

• Food Science and Biotechnology
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• v.18 no.1
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• pp.223-227
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• 2009

The fruits of Cornus kousa Burg. were extracted with 80% aqueous methanol (MeOH) and the concentrated extract was partitioned with ethyl acetate (EtOAc), n-butanol (n-BuOH), and $H_2O$. From the EtOAc traction, 5 triterpenoids were isolated through repeated silica gel ($SiO_2$), octadecyl silica gel (ODS), and Sephadex LH-20 column chromatography (c.c.). These compounds were determined to be ursolic acid (1), corosolic acid (2), taraxasterol (3), betulinic acid (4), and betulinic aldehyde (5) on the basis of their spectroscopic data including electronic ionization mass spectrometry, ultraviolet spectroscopy, infrared spectroscopy, and nuclear magnetic resonance. This is the first reported isolation of these compounds from this plant. Also, compounds 1, 3, 4, and 5 show a relatively high inhibitory activity against human acyl-CoA: cholesterol acyltransferase-1 (hACAT-1) with inhibition values of $52.8{\pm}0.7$, $91.1{\pm}0.4$, $93.0{\pm}0.7$, and $96.2{\pm}0.2%$ at a concentration of $100{\mu}M$, respectively.

• Journal of Environmental Science International
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• v.26 no.11
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• pp.1275-1284
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• 2017

Acyltransferase (AT) catalyzes the transfer of an acyl moiety from acyl-coenzyme A (acyl-CoA) to an acceptor. ATs play important roles in the maintenance of homeostasis in the human body and have been linked to various diseases; therefore, several ATs have been proposed as potential targets for the treatment or prevention of such diseases. The AT family includes acyl-CoA:cholesterol AT (ACAT), diacylglycerol AT, and monoacylglycerol AT for the metabolism of lipids. Furthermore, recent molecular biological studies revealed the existence of their isozymes with distinct functions in the body. ACAT plays a critical role in the formation of cholesteryl esters from cholesterol and fatty acids, and is a potential target for treating hypercholesterolemia. During an experiment designed to discover biologically active compounds from herbal medicines, we isolated two known guaianolide sesquiterpene lactones from Chrysanthemum boreale Makino (Compositae). The lactones were characterized from their spectroscopic data (NMR, IR, MASS). These compounds were subjected to ACAT inhibition assay. Here, we report the isolation and structural elucidation of the compounds 8-o-acetyl-2-methoxy-10-hydroxy-3,11(13)-guaiadiene-12,6-olide and 8-acetyl-3,10-hydroxy-4(15),11(13)-guaiadiene-12,6-olide. In the ACAT inhibition assay, compound 1 showed strong inhibitory activity, with an $IC_{50}$ value $45{\mu}g/mL$, whereas compound 2 did not exhibit significant inhibitory activity with an over $100{\mu}g/mL$.

• Microbiology and Biotechnology Letters
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• v.21 no.6
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• pp.600-608
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• 1993

About 1, 300 strains isolated from soil were evaluated for acyl-CoA:cholesterol acyltransferase (ACAT) inhibition activity. About 4.0% of actinomycetes and 3.6% of fungi showed greater than 50% inhibition activity, respectively. However, none of the isolated bacteria exhibited inhibition activity more than 50%. Among them, one Streptomyces sp. A-3 showed a higher ACAT inhibition activity in culture broth. Isolation of the ACAT inhibitor (AI-3) was achieved by Amberlite XAD-7 column, silica-gel column, Sephadex LH-20 gel-filtration and reverse phase HPLC.

• Journal of Applied Biological Chemistry
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• v.49 no.2
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• pp.57-61
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• 2006

Isoflavones 1-3 and pterocarpans 4-8 were isolated from methanol extract of roots of Glycine max. In inhibitory effect against human acyl-CoA:cholesterol acytransferase (ACAT)-1 and ACAT-2, glyceollin I 5 showed potent hACAT-1 ($IC_{50}=299.0{\mu}M$) and hACAT-2 ($IC_{50}=82.7{\mu}M$) inhibitory activities.

• Nutrition Research and Practice
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• v.10 no.5
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• pp.501-506
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• 2016

BACKGROUNG/OBJECTIVES: Corn silk (CS) extract contains large amounts of maysin, which is a major flavonoid in CS. However, studies regarding the effect of CS extract on cholesterol metabolism is limited. Therefore, the purpose of this study was to determine the effect of CS extract on cholesterol metabolism in C57BL/6J mouse fed high-fat diets. MATERIALS/METHODS: Normal-fat group fed 7% fat diet, high-fat (HF) group fed 25% fat diet, and high-fat with corn silk (HFCS) group were orally administered CS extract (100 mg/kg body weight) daily. Serum and hepatic levels of total lipids, triglycerides, and total cholesterol as well as serum free fatty acid, glucose, and insulin levels were determined. The mRNA expression levels of acyl-CoA: cholesterol acyltransferase (ACAT), cholesterol 7-alpha hydroxylase (CYP7A1), farnesoid X receptor (FXR), lecithin cholesterol acyltransferase (LCAT), low-density lipoprotein receptor, 3-hyroxy-3-methylglutaryl-coenzyme A reductase (HMG-CoA reductase), adiponectin, leptin, and tumor necrosis factor ${\alpha}$ were determined. RESULTS: Oral administration of CS extract with HF improved serum glucose and insulin levels as well as attenuated HF-induced fatty liver. CS extracts significantly elevated mRNA expression levels of adipocytokines and reduced mRNA expression levels of HMG-CoA reductase, ACAT, and FXR. The mRNA expression levels of CYP7A1 and LCAT between the HF group and HFCS group were not statistically different. CONCLUSIONS: CS extract supplementation with a high-fat diet improves levels of adipocytokine secretion and glucose homeostasis. CS extract is also effective in decreasing the regulatory pool of hepatic cholesterol, in line with decreased blood and hepatic levels of cholesterol though modulation of mRNA expression levels of HMG-CoA reductase, ACAT, and FXR.

• Preventive Nutrition and Food Science
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• v.5 no.2
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• pp.109-113
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• 2000

In this study, a potential mechanism through which the hesperidin might work on the effect was examined in vivo. Male rats were fed a high cholesterol synthetic diet (1%, wt/wt) with hesperidin (0.1%, wt/wt) for 42 days. Activity of hepatic HMG-CoA reductase was significantly lowered by the hesperidin supplement compared to the control. Hesperidin did not significantly alter plasma or hepatic lipids, but tended to lower those lipid levels. Hesperidin also subsequently reduced the fecal neutral sterols compared to the control(253.3mg/d vs.521.9 mg/d). The inhibition of HMG-CoA reductase resulting from the hesperidin supplementation could count for the reduction in fecal neutral sterols that appears to compensate for the decreased cholesterol biosynthesis. The dose of hesperidin in a high choles-terol diet should apparently be more than 0.1% to exhibit the hypocholesterolemic response in these rats. It remains to be determined whether the observed alterations in cholesterol metabolism are specific to the rat or also could be applied to the humans.

• Preventive Nutrition and Food Science
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• v.3 no.4
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• pp.344-350
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• 1998

Lipid lowering properties from three plant water extracts, Rosa rugosa, Crataegus pinnatifida and Polygonum cuspidatum, were tested by supplementing a 1% high-cholesterol diet with them in rats. Plasma triglyceride levels in Rosa fugosa, Crataegus pinnatifida and Polygonum cuspidatum groups were significantly lower compared to that of the control. by 29% , 24% and 47% respectively. hepatic trigylceride levels in Rosa rugosa and Crataegus pinnatifida groups were significantly lower compared to the control by 11% and 15% respectively. Hepatic HMG-CoA reductase activity in Rosa rugosa group was significantly greater compared to the control by 406%. Hepatic ACAT activity was significantly lower in Polygonum cuspidatum group compared to the control by 28%. by multiple regression results, only plasma cholesterol was associated significantly (p<0.05) with liver HMG-CoA reductase activity. Plasma cholesterol explained 12% of thevariance of the liver HMG-CoA redctase activity. In conclusion, we have showen that hot water extracts from Rosa rugosa, Crataegus pinnatifida and Polygonum cuspidatum lowered plasma triglycerides in rats fed on a high-cholesterol diet. Data suggests that these extracts could potentially prevent or treat hypertriglyceridemia induced by a high fat diet and fatty liver.