• Korean Journal of Clinical Laboratory Science
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• v.45 no.4
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• pp.131-138
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• 2013

Insulin resistance and pancreatic beta cell dysfunction have been established as being related to the diabetes. Lately, what is emphasizing is that those have been shown as something related to the metabolic syndrome and cardiovascular disease. Homeostasis model assessment (HOMA), simple index is calculated on blood levels of fasting glucose and insulin. And HOMA has been widely validated and applied for insulin resistance and pancreatic beta cell dysfunction. We also assessed the factors relative to insulin resistance and ${\beta}$ cell function determined by HOMA. The data from the 2010 Korean National Health and Nutrition Examination Survey were used. Analysis was done for 3,465 nondiabetic subjects (male 1,357, female 2,108). At baseline, anthropometric measurements were done and fasting glucose, insulin, lipid (Total cholesterol, HDL cholesterol, LDL cholesterol and Triglycerides) profiles were measured. HOMA-insulin resistance (HOMA-IR) and beta cell function (HOMA ${\beta}$-cell) were calculated from fasting glucose and insulin levels. In male, the value of HOMA-IR and HOMA ${\beta}$-cell was the highest among 30's and decreased as the age increased. In female, the value of HOMA-IR increased with age, while HOMA ${\beta}$-cell decreased. High HOMA-IR and low HOMA ${\beta}$-cell were associated with the highest value of fasting glucose and systolic blood pressure. Low HOMA-IR and high HOMA ${\beta}$-cell showed the lowest concentration of fasting glucose and the highest concentration of HDL cholesterol. High HOMA-IR and high HOMA ${\beta}$-cell were connected with BMI, Total cholesterol, LDL cholesterol, and Triglycerides. There was a negative correlation between HOMA ${\beta}$-cell and age. The correlation coefficients of HOMA-IR and HOMA ${\beta}$-cell showed the highest value among weight, BMI and WC.

• Journal of the Korean Society of Food Science and Nutrition
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• v.21 no.5
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• pp.580-593
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• 1992

Cholesterol have many essential functions as a component of cellular and subcellular membranes, metabolic precursor of bile acids and steroid hormones, and obligatory part of the metabolic systems involved in DNA synthesis and cell division. These essential funtions demand a continuous and appropriate supply of cholesterol to the tissues. Body cholesterol pool is maintained by the balance of acquirement from diets, de novo synthesis, and excretion either as bile acids or neutral steroids. In these metabolic process, cholesterol biosynthesis is controlled by the change in the activity of 3-hydroxy-3methylglutaryl coenzyme A (HMG-CoA) reductase. Under most physiological or nutritional situations, the activity of this enzyme is adroitly regulated to maintain tissue cholesterol balance. Excess cholesterol accumulation in the cells induces the decrease in the number of LDL-receptor, followed by the increase in the level of serum LDL-cholesterol. Increase in the level of serum cholesterol appears to be an important determinant for the incidence of the coronary heart disease. Dietary intervention may be helpful in alleviating an increase in the level of serum cholesterol or body cholesterol pool.

• Journal of the Korean Society of Food Science and Nutrition
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• v.25 no.3
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• pp.392-398
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• 1996

This study was carried out to determine the effects of sodium alginate and cellulose on the cholesterol metabolism in cholesterol-fed rats. Thirty male Sprague-Dawley rats were randomly assigned to three dietary treatments. Rats were fed, ad libitum, diets containing 10% dietary fibers as sodium alginate, cellulose or fiber-free with 1% cholesterol for 4 weeks. The results obtained were as follows: the feeding of sodium alginate with 1% cholesterol induced a significant decrease in plasma cholesterol and TG. The feeding of sodium alginate significantly decreased hepatic total lipids and TG levels, whereas the feeding of sodium alginate significantly increased hepatic HMG-CoA reductase activity. The feeding of sodium alginate and cellulose significantly increased fecal cholesterol and bile acid excretion. The excretion of TG in sodium alginate group, however, was two-fold and four-fold increased compared to cellulose and fiber-free group, respectively. As a result of this study, the ingestion of sodium alginate decreased plasma cholesterol and TG concentrations and liver TG concentration. This may be explained by the facts that fecal cholesterol, bile acid and TG level were increased significantly in sodium alginate group. The increased hepatic HMG-CoA reductase activity by sodium alginate feeding appears to be corresponded to whole-body cholesterol homeostasis.

• Korean Journal of Food Science and Technology
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• v.51 no.3
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• pp.272-277
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• 2019

The effects of medium-chain enriched diacylglycerol (MCE-DAG) oil on hepatic cholesterol homeostasis were investigated. HepG2 hepatocytes were treated with either 0.5, 1.0, or $1.5{\mu}g/mL$ of MCE-DAG for 48 h. There was no evidence of cytotoxicity by MCE-DAG up to $1.5{\mu}g/mL$. The level of proteins for cholesterol uptake including CLATHRIN and LDL receptor increased by MCE-DAG in a dose-dependent manner (p<0.05). Furthermore, proprotein convertase subtilisin/kexin type 9, an inhibitor of LDLR, was dose-dependently diminished (p<0.05), indicating cholesterol clearance raised. MCE-DAG significantly increased 3-hydroxy-3-methylglutaryl-coenzyme A reductase and acetyl-CoA acetyltransferase2 (p<0.05), required for cholesterol synthesis, and their transcriptional regulator sterol regulatory element-binding protein2 (p<0.05). These findings suggest that given conditions of prolonged sterol fasting in the current study activated both hepatic cholesterol synthesis and clearance by MCE-DAG. However, total intracellular level of cholesterol was not altered by MCE-DAG. Taken together, MCE-DAG has the potential to prevent hypercholesterolemia by increasing hepatic cholesterol uptake without affecting intracellular cholesterol level.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.1
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• pp.489-494
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• 2014

Background: Psychiatric patients appear to be at lower risk of cancer. Some antipsychotic drugs might have inhibitory effects on tumor growth, including penfluridol, a strong agent. To test this, we conducted a study to determine whether penfluridol exerts cytotoxic effects on tumor cells and, if so, to explore its anti-tumor mechanisms. Methods: Growth inhibition of mouse cancer cell lines by penfluridol was determined using the 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT) assay. Cytotoxic activity was determined by clonogenic cell survival and trypan blue assays. Animal tumor models of these cancer cells were established and to evaluate penfluridol for its anti-tumor efficacy in vivo. Unesterified cholesterol in cancer cells was examined by filipin staining. Serum total cholesterol and tumor total cholesterol were detected using the cholesterol oxidase/p-aminophenazone (CHOD-PAP) method. Results: Penfluridol inhibited the proliferation of B16 melanoma (B16/F10), LL/2 lung carcinoma (LL/2), CT26 colon carcinoma (CT26) and 4T1 breast cancer (4T1) cells in vitro. In vivo penfluridol was particularly effective at inhibiting LL/2 lung tumor growth, and obviously prolonged the survival time of mice bearing LL/2 lung tumors implanted subcutaneously. Accumulated unesterified cholesterol was found in all of the cancer cells treated with penfluridol, and this effect was most evident in LL/2, 4T1 and CT26 cells. No significant difference in serum cholesterol levels was found between the normal saline-treated mice and the penfluridol-treated mice. However, a dose-dependent decrease of total cholesterol in tumor tissues was observed in penfluridol-treated mice, which was most evident in B16/F10-, LL/2-, and 4T1-tumor-bearing mice. Conclusion: Our results suggested that penfluridol is not only cytotoxic to cancer cells in vitro but can also inhibit tumor growth in vivo. Dysregulation of cholesterol homeostasis by penfluridol may be involved in its anti-tumor mechanisms.

• The Korean Journal of Food And Nutrition
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• v.29 no.2
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• pp.290-299
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• 2016

This study was conducted to determine the association between dietary calcium intake and biomarkers related to lipid and glucose metabolism and inflammation in Korean patients with type 2 diabetes. Seventy-five subjects (41 males, 34 females) were recruited from a group of patients who had visited the department of endocrine medicine. Data on anthropometric characteristics, clinical indices such as hemoglobin A1c and C-reactive protein (CRP), and dietary nutrient intakes were collected. Subjects were divided into three groups on the basis of their calcium intake [< EAR (below estimated average requirement), EAR-RNI (between EAR and recommended nutrient intake), > RNI (above RNI)]. Average calcium intake of < EAR, EAR-RNI, > RNI groups were $462.7{\pm}18.7$, $649.7{\pm}12.8$, and $895.7{\pm}21.7mg$, respectively. Energy intake was not different among groups but intakes of protein, total and saturated fatty acids were significantly higher in > RNI group than < EAR group. Analysis of covariance revealed that HDL cholesterol level was significantly higher in EAR-RNI group, as compared to < EAR group after adjustment with confounders such as age, sex, BMI and energy intake (p < 0.05). Levels of CRP and homeostasis model assessment 2-insulin resistance (HOMA2-IR) were significantly lower in EAR-RNI group. Total cholesterol level was higher in EAR-RNI and > RNI groups, although within the normal range. Our results suggest that dietary calcium intake may influence the levels of HDL-cholesterol, CRP and HOMA2-IR and subsequently, help management/treatment of type 2 diabetes patients.

• Nutrition Research and Practice
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• v.8 no.4
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• pp.469-475
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• 2014

BACKGROUND/OBJECTIVE: The goal of the present study was to investigate the effects of moderate caloric restriction on ${\beta}$-cell function and insulin sensitivity in middle-aged obese Korean women. SUBJECTS/METHODS: Fifty-seven obese pre-menopausal Korean women participated in a 12-week calorie restriction program. Data on total cholesterol (TC), high density lipoprotein cholesterol (HDL-C), low density lipoprotein cholesterol (LDL-C), triglycerides (TG), and fasting serum levels of glucose, insulin, C-peptide, blood pressure, leptin and anthropometrics were collected. A dietary intake assessment was based on three days of food recording. Additionally, ${\beta}$-cell function [homeostasis model assessment of ${\beta}$-cell (HOMA-${\beta}$), insulinogenic index (ISI), C-peptide:glucose ratio, and area under curve insulin/glucose ($AUC_{ins/glu}$)] and insulin sensitivity [homeostasis model assessment for insulin resistance (HOMA-IR), Quantitative insulin-sensitivity check index (QUICKI) and Matsuda index (MI)] were recorded. RESULTS: When calories were reduced by an average of 422 kcal/day for 12 weeks, BMI (-2.7%), body fat mass (-10.2%), and waist circumference (-5%) all decreased significantly (P < 0.05). After calorie restriction, weight, body fat percentage, hip circumference, BP, TC, HDL-C, LDL-C, plasma glucose at fasting, insulin at fasting and 120 min, $AUC_{glu}$ and the insulin area under the curve all decreased significantly (all P < 0.05), while insulin sensitivity (HOMA-IR, QUICKI and Matsuda index) measured by OGTT improved significantly (P < 0.01). CONCLUSIONS: Moderate weight loss due to caloric restriction with reduction in insulin resistance improves glucose tolerance and insulin sensitivity in middle-aged obese women and thereby may help prevent the development of type 2 diabetes mellitus.

• Asian-Australasian Journal of Animal Sciences
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• v.23 no.5
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• pp.588-597
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• 2010

We investigated the effect of quercetin on growth and plasma cholesterol level and the effects of quercetin pretreatment (Diet 1, 0%; Diet 2, 0.25%; and Diet 3, 0.5% quercetin) for 30 and 60 days on oxidative stress induced by hypo-osmotic conditions (17.5, 8.75, and 4 psu) in olive flounder. The weights of flounder were higher with Diet 3 than with Diet 1 and 2, which indicated that a high concentration (Diet 3) of quercetin was very effective in growth. Total cholesterol levels were lower with Diets 2 and 3 than with Diet 1, leading us to hypothesize that quercetin removed low-density lipoproteins from circulation and thereby reduced total cholesterol. To understand the antioxidant role of quercetin, we measured the mRNA expression and activities of superoxide dismutase (SOD) and catalase (CAT) and the $H_2O_2$ concentration in quercetin-treated flounder exposed to osmotic stress. The $H_2O_2$ concentration and the SOD and CAT expression and activity levels were lower in flounder fed with Diets 2 and 3 than with Diet 1, suggesting that quercetin directly scavenges reactive oxygen species to reduce oxidative stress. Furthermore, the plasma lysozyme activity and osmolality were higher with Diets 2 and 3 than with Diet 1, indicating that quercetin increases immune function and helps to maintain physiological homeostasis. Plasma cortisol was lower with Diets 2 and 3 than with Diet 1, suggesting the quercetin protects against stress. These results indicate that quercetin has hypocholesterolemic and antioxidant effects, increases immune function, and acts to maintain physiological homeostasis.

• 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.

• Biomolecules & Therapeutics
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• v.15 no.1
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• pp.34-39
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• 2007

Alzheimer's disease (AD) is an abnormal accumulation of the ${\beta}$-amyloid protein $(A{\beta})$ in specific brain region. It has been speculated that disturbance in cholesterol homeostasis may contribute to the etiology of AD by increasing $A{\beta}$ generation. However, conclusive evidence and possible mechanism has not been reported. In the present study, we demonstrated that rabbits treated with 0.5% cholesterol for 16 weeks increased serum total cholesterol, triacylglycerol, and low-density lipoprotein levels. $A{\beta}$ levels is higher in the hippocampus of brain in cholesterol dieted rabbits than that of normal diet rabbis. Expression and activities of ${\beta}-$ and ${\gamma}-$ secretases, the enzymes that cleave ${\beta}$-amyloid precursor protein to generate $A{\beta}$, were also increased in hippocampus of high cholesterol dieted rabbit than those of normal dieted rabbits. Our results suggest that high cholesterol diet may be associated with increased $A{\beta}$ accumulation in the brain of rabbits, and suggest that high cholesterol diet may be causal factor in the development or progression of AD.