Ryowon Choue

Obesity, Inflammation and Diet

Obesity is a state in which there is an over-accumulation of subcutaneous and/or abdominal adipose tissue. This adipose tissue is no longer considered inert and mainly devoted to storing energy; it is emerging as an active tissue in the regulation of physiological and pathological processes, including immunity and inflammation. Adipose tissue produces and releases a variety of adipokines (leptin, adiponectin, resistin, and visfatin), as well as pro- and anti-inflammatory cytokines (tumor necrosis factor-α, interleukin [IL]-4, IL-6, and others). Adipose tissue is also implicated in the development of chronic metabolic diseases such as type 2 diabetes mellitus or cardiovascular disease. Obesity is thus an underlying condition for inflammatory and metabolic diseases. Diet or dietary patterns play critical roles in obesity and other pathophysiological conditions. A healthy diet and some nutrients are generally considered beneficial; however, some dietary nutrients are still considered controversial. In this article, dietary factors that influence inflammation associated with obesity are discussed.

Preventive effect of the flavonoid, wogonin, against ethanol-induced gastric mucosal damage in rats

Whether wogonin (5,7-dihydroxy-8-methoxyflavone), a flavonoid originated from the root of Scutellaria baicalensis Georgi, which has been shown to have antiinflammatory and antitumor activities in various cell types, possesses a gastric cytoprotective effect was investigated in an ethanol-induced gastric damage model in rats. Ethanol administration alone induced evident gastric damage including gastric hemorrhages and edema, while this gastric damage was significantly attenuated by wogonin pretreatment (30 mg/kg B.W.) 1 hr before ethanol administration. As major protective mechanisms of wogonin on ethanol-induced gastric damage, we found that wogonin showed either antiinflammatory effects through dual actions on arachidonic acid metabolism, i.e., induction of prostaglandin D2 and suppression of 5S-hydroxyeicosatetraenoic acid (5S-HETE), or preventive induction of profuse apoptosis in the stomach. Conclusively, the flavonoid wogonin could be used as a preventive agent of alcohol-induced gastropathy, whose actions were proven to be strong antiinflammation and apoptosis induction.

Sociodemographic Disparities in the Composition of Metabolic Syndrome Components Among Adults in South Korea

OBJECTIVE Metabolic syndrome (MetS) is becoming a serious public health concern in many countries, including South Korea, which has faced remarkable changes in lifestyles and disease patterns in recent decades. We examined sex and socioeconomic status (SES) disparities in MetS and its components among South Koreans using recent, nationally representative data. RESEARCH DESIGN AND METHODS Data from the 2007−2008 Korea National Health and Nutrition Examination Surveys for 7,289 adults 19−65 years of age were used to examine the patterns of MetS components (defined using International Diabetes Federation criteria), and regression models were used to study the association of MetS with SES, indicated by education and family income levels. RESULTS MetS prevalence increased with age, from 4.6% at age 19−29 years to 25.0% at age 50−65 years. More men had MetS than women (15.8 vs. 11.6%); men had worse levels of all MetS components. In women, the low-income and low-education group was more likely to have MetS (odds ratio 2.75 [95% CI 1.75–4.31]); the high-income and high-education group was 52% less likely to have MetS (0.48 [0.25–0.89]) compared with the middle-income and middle-education group. The most common combination of MetS components was central obesity + low HDL cholesterol (HDL-C) + hypertriglyceridemia, which occurred in 15.5% of all MetS patients and in 3.4% of all South Korean adults (4.1% in men and 2.9% in women). CONCLUSIONS Those who were older and male as well as low-SES female had higher rates of MetS and its components in South Korea. The SES-MetS association was not found in men. Central obesity + low HDL-C + hypertriglyceridemia was the most common MetS pattern regardless of the SES.

Effects of Scutellariae radix and Aloe vera gel extracts on immunoglobulin E and cytokine levels in atopic dermatitis NC/Nga mice

AIM OF THE STUDY The present study aimed to investigate the effects of Scutellariae radix (SR) and Aloe vera gel (AV), alone or in combination, on levels of immunoglobulin E (IgE) and inflammatory cytokines in spontaneous atopic dermatitis(AD)-like skin lesions. MATERIALS AND METHODS After spontaneous AD-like skin lesion was developed by adaptation to conventional conditions, mice were randomly assigned to control, SR (50 mg/kg, p.o.), AV (0.8 mg/kg, p.o.) and SRAV (50 mg of SR and 0.8 mg of AV/kg, p.o.) groups, and were treated for 6 weeks. RESULTS SR and SRAV suppressed IL-5 levels compared with control, but had no effects on IgE levels (P<0.05). AV increased IgE levels, but decreased both IL-5 and IL-10 compared with control (P<0.05). CONCLUSION These results suggest that SR and AV modulate immunological responses in AD, mainly through influencing IL-5 or IL-10 levels.

Effects of d-α-tocopherol supplements on lipid metabolism in a high-fat diet-fed animal model

High-fat diet up-regulates either insulin resistance or triglycerides, which is assumed to be related to the expression of peroxisome proliferator-activated receptor (PPAR)-α and PPAR-γ. The beneficial effects of vitamin E on insulin resistance are well known; however, it is not clear if vitamin E with a high-fat diet alters the expression of PPAR-α and PPAR-γ. We investigated the effects of d-α-tocopherol supplementation on insulin sensitivity, blood lipid profiles, lipid peroxidation, and the expression of PPAR-α and PPAR-γ in a high-fat (HF) diet-fed male C57BL/6J model of insulin resistance. The animals were given a regular diet (CON; 10% fat), a HF diet containing 45% fat, or a HF diet plus d-α-tocopherol (HF-E) for a period of 20 weeks. The results showed that the HF diet induced insulin resistance and altered the lipid profile, specifically the triglyceride (TG) and total cholesterol (TC) levels (P < 0.05). In this animal model, supplementation with d-α-tocopherol improved insulin resistance as well as the serum levels of TG and very-low-density lipoprotein-cholesterol (VLDL-C) (P < 0.05). Moreover, the treatment decreased the levels of malondialdehyde (MDA) in the serum and liver while increasing hepatic PPAR-α expression and decreasing PPAR-γ expression. In conclusion, the oral administration of d-α-tocopherol with a high-fat diet had positive effects on insulin resistance, lipid profiles, and oxidative stress through the expression of PPAR-α and PPAR-γ in a high-fat diet-fed male mice.

Plasma pharmacokinetics and urinary excretion of isoflavones after ingestion of soy products with different aglycone/glucoside ratios in South Korean women

Asian populations are thought to receive significant health benefits from traditional diets rich in soybeans due to high isoflavone contents. However, available epidemiologic data only weakly support this hypothesis. The present study was carried out to assess the pharmacokinetics of isoflavones in South Korean women after ingestion of soy-based foods. Twenty-six healthy female volunteers (20-30 y old) consumed three different soy products (i.e., isogen, soymilk, and fermented soybeans) with different aglycone/glucoside ratios. Plasma and urine isoflavone concentrations were measured by high-performance liquid chromatography (HPLC) after ingestion of one of the soy products. Pharmacokinetic parameters were determined using the WinNonlin program. The area under the curve (AUC) for plasma daidzein levels of the soymilk group (2,101 ± 352 ng · h/mL) was significantly smaller than those of the isogen (2,628 ± 573 ng · h/mL) and fermented soybean (2,593 ± 465 ng · h/mL) groups. The maximum plasma concentration (Cmax) of daidzein for the soymilk group (231 ± 44 ng/mL) was significantly higher than those of the isogen (160 ± 32 ng/mL) and fermented soybean (195 ± 35 ng/mL) groups. The half-lives of daidzein and genistein in the soymilk group (5.9 and 5.6 h, respectively) were significantly shorter than those in the individuals given isogen (9.6 and 8.5 h, respectively) or fermented soybean (9.5 and 8.2 h, respectively). The urinary recovery rates of daidzein and genistein were 42% and 17% for the isogen group, 46% and 23% for the fermented soybean group, and 33% and 22% for the soymilk group. In conclusion, our data indicated that soy products containing high levels of isoflavone aglycone are more effective for maintaining plasma isoflavone concentrations. Additional dose-response, durational, and interventional studies are required to evaluate the ability of soy-based foods to increase the bioavailability of isoflavones that positively affect human health.

Dietary intervention with emphasis on folate intake reduces serum lipids but not plasma homocysteine levels in hyperlipidemic patients.

Hyperlipidemia and hyperhomocysteinemia are regarded as major risk factors for cardiovascular disease. Medical nutrition therapy (MNT), which involves a combination of nutritional diagnosis, therapy, and counseling for at-risk patients, has been proposed as a protocol to control these risk factors. The purpose of this study was to investigate the effect of an intensive MNT, specifically tailored to Korean hyperlipidemic patients, on levels of serum lipids and plasma homocysteine. Forty hyperlipidemic patients with blood levels of total cholesterol > or = 200 mg/dL or triacylglycerol > or = 150 mg/dL were recruited from the Kyung Hee University Medical Center (Seoul, Korea). They were randomly divided into control (no treatment) or experimental (MNT treatment) groups. A registered dietitian performed MNT, emphasizing dietary folate intake based on the guidelines for Korean hyperlipidemic patients; this was performed 5 times during the 12 weeks of the experiment. After the MNT period, we observed that body mass index (P < .001) and fat percentage (P < .05) was significantly decreased in the experimental group but not in the control group. Daily energy consumption, as well as carbohydrate, fat, and cholesterol intakes, all decreased significantly (P < .05) in the MNT group, whereas folate intake increased (P < .05). Blood levels of triacylglycerol (-30.8%), total cholesterol (-20.9%), low-density lipoprotein cholesterol (-14.5%), and ratio of low-density lipoprotein/high-density lipoprotein (-17.1%) were significantly lower in the experimental group after MNT (P < .001) compared with the control group. Plasma homocysteine levels were unchanged (P = .98); however, the levels of folate (P < .01), vitamin B(6) (P < .01), and vitamin B(12) (P < .05) increased significantly in the experimental group. These results indicate that MNT, with an emphasis on folate intake, can be effective at reducing blood levels of lipids and improving the blood levels of folate, vitamin B(6), and vitamin B(12) in Korean hyperlipidemic patients.

I3C and ICZ inhibit migration by suppressing the EMT process and FAK expression in breast cancer cells

Indole-3-carbinol (I3C) and indole[3,2-b] carbazole (ICZ) are major bioactive food components in cruciferous vegetables. Although previous studies have demonstrated the anticancer activity of I3C and ICZ in various types of cancer cells, the manner in which indole compounds regulate migration or related epithelial-to-mesenchymal transitions (EMT) has yet to be determined. In this study, we investigated the effects of I3C and ICZ on migration using breast cancer cells (MCF-7 and MDA-MB231). Pre‑treatment with I3C and ICZ significantly inhibited the migration of breast cancer cells without cytotoxicity, as measured by monolayer scratch assay. In addition, I3C and ICZ decreased vimentin (a mesenchymal marker) and focal adhesion kinase (FAK) mRNA expression, while increasing E-cadherin (an epithelial marker) expression. Matrix metalloproteinase (MMP)-2 and -9 activity was also reduced by I3C and ICZ. Taken together, we propose that I3C and ICZ pre‑treatment inhibits the migration of breast cancer cells through suppression of the EMT process and reduced MMP activity by repressing FAK expression. Our findings suggested that I3C and ICZ are potential compounds for inhibition of breast cancer cell migration.

Effect of onion peel extract on endothelial function and endothelial progenitor cells in overweight and obese individuals

OBJECTIVES Acute or chronic intake of polyphenol-rich foods has been reported to improve endothelial function. Quercetin, found abundantly in onion, is a potent antioxidant flavonoid. The aim of this study was to investigate whether consumption of onion peel extract (OPE) improves endothelial function in healthy overweight and obese individuals. METHODS This was a randomized double-blind, placebo-controlled study. Seventy-two healthy overweight and obese participants were randomly assigned to receive a red, soft capsule of OPE (100 mg quercetin/d, 50 mg quercetin twice daily; n = 36 participants) or an identical placebo capsule (n = 36) for 12 wk. Endothelial function, defined by flow-mediated dilation (FMD), circulating endothelial progenitor cells (EPCs) by flow cytometry, and laboratory test were determined at baseline and after treatment. RESULTS Baseline characteristics and laboratory findings did not significantly differ between the two groups. Compared with baseline values, the OPE group showed significantly improved FMD at 12 wk (from 12.5 ± 5.2 to 15.2 ± 6.1; P = 0.002), whereas the placebo group showed no difference. Nitroglycerin-mediated dilation did not change in either group. EPC counts (44.2 ± 25.6 versus 52.3 ± 18.6; P = 0.005) and the percentage of EPCs were significantly increased in the OPE group. When FMD was divided into quartiles, rate of patients with endothelial dysfunction defined as lowest quartile (cutoff value, 8.6%) of FMD improved from 26% to 9% by OPE. CONCLUSION Medium-term administration of OPE an improvement in FMD and circulating EPCs.

Moderate diet-induced weight loss is associated with improved insulin sensitivity in middle-aged healthy obese Korean women

BACKGROUND/OBJECTIVE The goal of the present study was to investigate the effects of moderate caloric restriction on β-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, β-cell function [homeostasis model assessment of β-cell (HOMA-β), insulinogenic index (ISI), C-peptide:glucose ratio, and area under curve insulin/glucose (AUCins/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, AUCglu 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.