• Korean Journal of Food Science and Technology
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• v.45 no.5
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• pp.628-635
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• 2013

We investigated the effects of water extracts of unripe black raspberry (UBR) and red ginseng (RG) on cholesterol synthesis, 3-hydroxy-3-methylglutaryl (HMG)-CoA reductase activity, and expression of low-density lipoprotein (LDL) or high-density lipoprotein (HDL)-related genes in HepG2 and Caco-2 (human hepatoma and intestinal cell lines, respectively). Our results showed that cholesterol synthesis and HMG-CoA reductase activity in HepG2 cells were inhibited by UBR and RG. Further, co-treatment with UBR and RG had a greater effect than did treatment with either UBR or RG. In Caco-2 cells, treatment with UBR and RG increased the expression of LDL-regulated genes, such as LDL receptor and SREBP-2, and also upregulated the level of HDL-associated ABCA1. Moreover, co-treatment with UBR and RG appeared to be more effective than treatment with either UBR or RG. Taken together, our results indicate that UBR and RG regulate the level of HDL-associated ABCA1 via signaling pathway, thereby preventing cholesterol synthesis.

• 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.11 no.1
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• pp.42-47
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• 2006

This study investigated the effects of mulberry leaf extract on lipid metabolism in rats fed a high cholesterol diet. Sprague-Dawley male rats weighing $100{\pm}10g$ were randomly assigned either to one of two normal diet groups, with (NE group) or without (N group) mulberry extract, or one of four high cholesterol groups containing 1% cholesterol and various levels of dietary mulberry leaf extract. The rats fed high cholesterol diets were subdivided into 4 groups according to level of mulberry extract; Mulberry extract free group (HC group), 0.8% mulberry leaf extract group (HCL group), 1.6% mulberry leaf extract (HCM group) and 3.2% mulberry leaf extract (HCH group). The rats were fed their respective diets ad libitum for 4 weeks. The levels of serum triglyceride, total cholesterol and LDL-cholesterol of the HC group were higher than mulberry leaf extract supplemented groups. In contrast, the levels of serum HDL-cholesterol in groups supplemented with mulberry leaf extract were significantly lower than that of HC group. Hepatic total lipids, triglycerides, and cholesterol were significantly higher in the high cholesterol groups compared to those of the normal group, but were lower in the HCL, HCM and HCH groups than in the HC group. HMG-CoA reductase activity was significantly decreased in the HC and HCL groups compared to the normal and NE groups. However, the activities in the HCM and HCH group were similar to that of the normal group. The activity of acyl-CoA-cholesterol acyl transferase (ACAT) was increased in high cholesterol groups compared to the normal group. However, the activity was lower for all of the high cholesterol groups fed mulberry leaf extracts, and was lowest for the highest supplemented group (HCH), with no significantly difference from the normal group. In conclusion, the reduction in serum and hepatic lipid composition by mulberry leaf extract may be due to its modulation of HMG-CoA reductase and ACAT activities.

• KSBB Journal
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• v.6 no.1
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• pp.55-61
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• 1991

The objective of this in vitro study is to screen a possible inhibitor, originated from some chinese herb medicines, of 3-hydroxy-3-methylglutaryl Coenzyme A (HMG-CoA) reductase that is the major regulatory enzyme of hepatic cholesterol biosynthesis. Fourteen kinds of herbal plant were extracted with water and evaporated for prescreening. The methanol extracts of the effective 3 kinds (9 species) were fractionated with chloroform, ethylacetate, butanol and water, and vacuum evaporated. The degree of inhibition of the extracts to HMG-CoA reductase activity was calculated by the spectrophotometric method using microsomal protein of Saccharomyces cerevisiae ATCC 42949 as an enzyme source. Among these samples, marked inhibitory effects were observed in the extracts of ethylacetate and chloroform fractions of the Rosa rugosa roots, and those of butanol, ehtylacetate and water fractions of pine leaves. Also, the inhibitory effects of the extracts obtained from buckwheat shell and the roots of Rosaceae were found.

• Journal of Pharmacopuncture
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• v.14 no.3
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• pp.63-69
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• 2011

Objectives : The purpose of this study is to evaluate the effect of Artemisia capillaries on gene expression of lipid metabolism in rats. Methods : The author performed several experimental items to analyze the total cholesterol and triglyceride in liver tissue, the gene expressions of CYP7A1 and HMG-CoA reductase. Results : 1. In Artemisia capillaries group, the levels of total cholesterol in liver tissue were significantly decreased. 2. In Artemisia capillaries group, the ratios of CYP7A1, HMG-CoA reductase were as same as the normal group. Conclusions : From the above results, Artemisia capillaries can be used to treat hyperlipidemia.

• Journal of Nutrition and Health
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• v.33 no.4
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• pp.395-402
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• 2000

This study was carried out to explore the hypocholesterolemic effect of dehyulled defatty soy flour and its possible mechanisms including endocrine status, cholesterol biosynthesis, and fecal excretion in rats. Animals fed casein were used as control and each phospholipid compared with casein feeding. Cholesterol concentrations in all lipoprotein fraction were significantly lower in defatted soy flour group compared with casein-fed control. Defatted soy flour feeding also significantly lowered hepatic total lipid, cholesteol and TG, and increaed fecal bile acid excretion by 270% compared with casein feeding. Defattd soy flour feeding had no significant effect on plasma thyroid hormone levels and hepatic 3-hydroxy-3-methyl glutary coenzyme A(HMG-CoA) reductase activity. However, plasma T4 concentration was slightly elevated and HMG-CoA reductase activity was suppressed in defatted soy flour group. These metabolic alterations partially explain the reduced plasma and hepatic cholesterol levels of rats fed defatted soy flour.

• Journal of the Korean Society of Food Science and Nutrition
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• v.27 no.6
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• pp.1217-1222
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• 1998

This study was conducted to investigate the effect of mulberry leaves on lipid metabolism in cho lesterol induced hypercholesterolemia rats. The mulberry treatment group showed decreases of serum lipid concentration compared with hyperlipidemic group. Also, Mulberry leaves inhibited the activity of HMG Co A reductase, increased lipase activity. In histopathological examination, abdominal aorta showed no critical lesions with mulberry leaves treatment. These results suggest that hypolipidemic effects of mulberry leaves on rats were the inhibition of cholesterol synthesis and acceleration of cholesterol catabolism in the liver. For human, serum triglyceride contents were more significantly decreased with treatment of mulberry leaves powder.

• Korean Journal of Pharmacognosy
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• v.30 no.4
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• pp.368-376
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• 1999

Twenty-four Oriental herbal medicines including Platycodi Radix and Scutellariae Radix, etc., which have been used for the cure of hyperlipidemia, coronary heart, disease were evaluated for the 3-hydroxy-3-methylglutaryl coenzyme A(HMG-CoA) reductase inhibition and antioxidant effect on a free radical, 1,1-diphenyl-2-picrylhydrazyl(DPPH) in vitro, and antihyperlipidemic effect on hyperlipidemic rats induced by Triton WR-1339 in vivo. 80% MeOH extract of eight herbs including Scutellariae Radix, Coptidis Rhizoma, Paeoniae Radix Rubra, Moutan Cortex Radicis, Angelicae Gigantis Radix, Bambusae Caulis in Taeniam, Cinnamomi Ramulus and Crataegi Fructus inhibited the HMG-CoA reductase activities and exhibited a radical-trapping action on a stable free radical, DPPH. On Triton WR-1339-induced hyperlipidemic rats, four herbs including Scutellariae Radix, Angelicae Gigantis Radix, Bambusae Caulis in Taeniam and Cinnamomi Ramulus showed respectively the significant suppression of serum total cholesterol, triglyceride, phospholipid and LDL-cholesterol levels and serum transaminase(ALT and AST) activities. From these results, it is suggested that each 80% MeOH extract of Scutellariae Radix, Angelicae Gigantis Radix, Bambusae Caulis in Taeniam and Cinnamomi Ramulus have effective antihyperlipidemic action against hyperlipidemia.

• Preventive Nutrition and Food Science
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• v.6 no.2
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• pp.122-125
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• 2001

A potential mechanism through which the jujube extract might produce a cholesterol-lowering effect was compared with that of tangerine peel extract in vivo. Two extracts were prepared using ethanol. Male rats were fed a high cholesterol (1%, w/w) lab chow with jujube extract (1.2%) or tangerine peel extract (6.3%, w/w) for 3 weeks. Activities of hepatic HMG-CoA reductase (289.6$\pm$12.9 and 296.7$\pm$11.6 nmole/min/mg vs. 347.9$\pm$17.5 nmole/min/mg) and ACAT (554.8$\pm$18.2 and 451.7$\pm$19.4 nmole/min/mg vs. 602.6$\pm$21.4 nmole/min/mg) were significantly lowered by both supplements compared to the control group. These two supplements also substantially reduced the concentrations of plasma cholesterol (103.3$\pm$15.9 and 101.6$\pm$19.4 mg/dL vs. 141.6$\pm$18.1 mg/dL) and triglyceride (61.3$\pm$5.5 and 55.5$\pm$3.9 mg/dL vs. 96.0$\pm$4.2 mg/dL). The inhibition of HMG-CoA reductase resulting from the supplementation of jujube or tangerine extracts could count for the reduction in plasma cholesterol. Accordingly, lipid-lowering action of both supplements appears to be similar in high-cholesterol fed rats.

• Nutritional Sciences
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• v.9 no.4
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• pp.259-266
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• 2006

The current study examined the effect of quercetin supplements on the lipid-lowering and antioxidant metabolism in ethanol-fed rats. The control $group(E_8)$ received ethanol only diet for 8 wks, whereas the other group$(E_8Q_4)$ received a diet including quercetin supplementation(0.05% wt/wt) for 4 wks while on the ethanol diet for 8wks. The hepatic alcohol dehydrogenase activity was significantly higher in the $E_8Q_4$ group than in the $E_8$ group. Supplementation with quercetin significantly elevated the HDL- cholesterol concentration, the HDL-C/total-C ratio, and lowered the atherogenic index(AI) compared to the $E_8$ group. The hepatic triglyceride and cholesterol contents were significantly lowered by the quercetin supplement compared to those of the control group. The hepatic HMG-CoA reductase and ACAT activities of the $E_8Q_4$ group were significantly lower than those of the $E_8$ group. The overall potential for antioxidant defense was significantly enhanced by the quercetin supplement, as indicated by a decrease in plasma and hepatic TBARS levels. The hepatic GSH-Px and G6PD activities were significantly higher in the $E_8Q_4$ group compared to the $E_8$ group. The current results suggest that dietary quercetin leads to the inhibition of HMG-CoA reductase and ACAT, which in turn lowers cholesterol levels and normalizes antioxidant enzyme activities.