Jung-Eun Yim

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.

Hepatoprotective effects of Rubus coreanus miquel concentrates on liver injuries induced by carbon tetrachloride in rats

As well-being foods pursuing healthy life are becoming popular, interest in Rubus coreanus Miquel (RCM) fruit, a type of Korean blackberry, is increasing due to its medicinal actions including protecting the liver, brightening the eyes, and alleviating diabetes. This study was carried out to evaluate the hepatoprotective effects of RCM concentrates on liver injuries induced by carbon tetrachloride (CCl4) in rats. RCM, produced in June ~ July 2008 at Chunbook, Gochang (South Korea), was finely mashed. The seeds were removed and the juices were condensed. Thirty-two Sprague-Dawley rats were divided into four groups according to treatment: normal (eight rats), CCl4, 1% RCM, and 2% RCM. Experimental diets were provided to the experimental animals for 4 weeks. We measure total cholesterol, high density lipoprotein-cholesterol (HDL-C), aspartate amino transferase (AST), alanine amino transferase (ALT), and alkaline phosphatase (ALP) levels. Part of the livers was isolated for histopathological evaluation, and analyzed for lipid peroxide (TBARS), superoxide dismutase (SOD) and liver proteins. The activities of serum AST, ALT, and ALP were elevated following CCl4 administration. Levels of hepatic TBARS were also significantly increased in the CCl4 groups. However, hepatic TBARS levels and the activities of serum enzymes were markedly reduced by supplementation with the RCM concentrates (P < 0.05). Hepatic SOD activity increased in the RCM concentrates group versus CCl4 groups. Histopathological examination revealed massive necrosis in the centrilobular area and degenerative changes caused by CCl4 were ameliorated by dietary supplementation with RCM concentrates. These results suggest that RCM concentrates have hepatoprotective effects and may improve the symptoms of liver injuries.

Antioxidative Activity of Onion Peel Extract in Obese Women: A Randomized, Double-blind, Placebo Controlled Study

Background: Quercetin, found abundantly in onion peel, has been known to have anticholesterol, antithrombotic and insulin-sensitizing properties. Here, we investigated the effect of quercetin-rich onion peel extract (OPE) on reactive oxygen species (ROS) production and antioxidative defense in obese woman. Methods: This study was randomized, double-blind, placebo controlled study. Thirty-seven healthy obese participants were randomly assigned that eighteen subjects received red soft capsuled OPE (100 mg/d, 50 mg bis in die), while the other nineteen subjects received same capsuled placebo for 12 weeks. ROS production and superoxide dismutase (SOD) activity in plasma were determined by using ROS and SOD assay kits, respectively. Results: Baseline characteristics of anthropometric indicators and blood metabolic profiles were not significantly different between the two groups. Compared with baseline values, OPE consumption significantly reduced waist and hip circumference. Plasma ROS level and SOD activity were decreased in both placebo and OPE groups compared with baseline values. However, plasma ROS level in OPE group was significantly lower than in placebo group while plasma SOD activity in OPE group was significantly higher than in placebo group after 12 weeks of consumption. Conclusions: These findings indicate that OPE consumption may exert antioxidative effect by preventing the decrease of SOD activity as well as the production of ROS in obese women.

The association between measurement sites of visceral adipose tissue and cardiovascular risk factors after caloric restriction in obese Korean women.

Quantities as well as distributions of adipose tissue (AT) are significantly related to cardiovascular disease (CVD) risk factors and can be altered with caloric restriction. This study investigated which cross-sectional slice location of AT is most strongly correlated with changes in CVD risk factors after caloric restriction in obese Korean women. Thirty-three obese pre-menopausal Korean women (32.4 ± 8.5 yrs, BMI 27.1 ± 2.3 kg/m2) participated in a 12 weeks caloric restriction program. Subcutaneous adipose tissue (SAT) and visceral adipose tissue (VAT) were measured using computed tomography (CT) scans at the sites of L2-L3, L3-L4, and L4-L5. Fasting serum levels of glucose, insulin, triglyceride, total cholesterol (TC), low density lipoprotein cholesterol (LDL-C), high density lipoprotein cholesterol (HDL-C), leptin and homeostasis model assessment-insulin resistance (HOMA-IR) were observed. Pearsons partial correlation coefficients were used to assess the relationship between AT measurement sites and changes in CVD risk factors after calorie restriction. When calories were reduced by 350 kcal/day for 12 weeks, body weight (-2.7%), body fat mass (-8.2%), and waist circumference (-5.8%) all decreased (P < 0.05). In addition, following caloric restriction, serum levels of glucose (-4.6%), TC (-6.2%), LDL-C (-5.3%), leptin (-17.6%) and HOMA-IR (-18.2%) decreased significantly (P < 0.05) as well. Changes in VAT at the level of L3-L4 were significantly greater than those at other abdominal sites, and these changes were correlated with changes in TC (P < 0.05), LDL-C (P < 0.001), SBP (P < 0.001) and HOMA-IR (P < 0.01). These results show that VAT at L3-L4 had a stronger correlation with CVD risk factors than with other AT measurement sites after caloric restriction.

Antidiabetic Effects of Gastric Banding Surgery in Morbidly Obese Patients with Type 2 Diabetes Mellitus

This study was performed to investigate the effect of gastric banding surgery on the improvement of glycated hemoglobin (HbA1c) of morbidly obese (MO) patients with type 2 diabetes mellitus (T2DM) with the consideration that obesity was associated with insulin resistance and T2DM. We retrospectively reviewed the medical records of 38 MO with T2DM patients and 50 MO patients. Pre-surgery and post-surgery data were analyzed a year later. The medical data from these patients, including sex, age, height, weight, body composition, HbA1c, triglyceride, total cholesterol, aspartate transaminase (AST), and alanine transaminase (ALT) were measured. There were significant reductions of body weight and body mass index (BMI), body fat, body fat percentage, waist-hip ratio, visceral fat, and obesity in each group before and after gastric banding surgery. Results of AST, ALT, and HbA1c had significant reductions in each group. For HbA1c, treatment rate was 71% in the MO group with T2DM with significant reduction of 22.8%. It is thought that a gastric banding surgery is one of the breakthrough methods not only for weight loss but also for the prevention of complication of the obese patients with T2DM. Thus, gastric banding surgery could be effective in controlling HbA1c in obese patients with type 2 diabetes mellitus.

Effects of zinc supplementation on catch-up growth in children with failure to thrive

BACKGROUND/OBJECTIVES Although globally the numbers of children diagnosed with failure to thrive (FTT) have decreased, FTT is still a serious pediatric problem. We aimed to investigate the effects of zinc supplementation for 6 months on growth parameters of infants and children with FTT. SUBJECTS/METHODS In this retrospective study, of the 114 participants aged between 4 months and 6 years, 89 were included in the zinc supplementation group and were provided with nutrition counseling plus an oral zinc supplement for 6 months. The caregivers of the 25 participants in the control group received nutrition counseling alone. Medical data of these children, including sex, age, height, weight, serum zinc level, and serum insulin-like growth factor 1 (IGF1) level were analyzed. RESULTS Zinc supplementation for 6 months increased weight-for-age Z-score and serum zinc levels (5.5%) in the zinc supplementation group of underweight category children. As for stunting category, height-for-age Z-score of the participants in the zinc supplementation group increased when compared with the baseline, and serum zinc levels increased in the normal or mild stunting group. Serum IGF1 levels did not change significantly in any group. Thus, zinc supplementation was more effective in children in the underweight category than those in the stunted category; this effect differed according to the degree of the FTT. CONCLUSION These findings suggest that zinc supplementation may have beneficial effects for growth of infants and children with FTT, and zinc supplementation would be required according to degree of FTT.

Effects of Erythrocyte Membrane Polyunsaturated Fatty Acids in Overweight, Obese, and Morbidly Obese Korean Women

Background The levels of erythrocyte polyunsaturated fatty acids (FAs) may be associated with obesity, metabolic syndrome, and cancer. Thus, we investigated the association between erythrocyte n−3 and n−6 FA composition, body mass index (BMI), and biochemical profiles. Methods The body composition, dietary intake, and blood parameters, including serum lipid, glucose, insulin, adipokines, oxidative stress, and erythrocyte FA, were assessed in 66 overweight and obese women (average age, 43.4 years). We also classified the participants into the overweight, obese, and morbidly obese (MO) groups based on the BMI values of 23, 25, and 30 kg/m2, respectively. Erythrocyte FA was measured via gas chromatography. Results The serum glucose, triglyceride, total cholesterol, and low-density lipoprotein cholesterol levels of the participants in the overweight, obese, and MO groups were not significantly different. However, the serum insulin, high-density lipoprotein, cholesterol and leptin levels were significantly different. The erythrocyte n−6/n−3 ratios of the overweight, obese, and MO groups were 2.4, 2.5, and 2.8, respectively. These data were consistent with the dietary n−6/n−3 ratio findings. Moreover, the erythrocyte n−6/n−3 ratio was correlated with serum insulin levels. Conclusions As the severity of obesity increased, the levels of insulin and leptin and the ratio of dietary n−6/n−3 increased, which was consistent with erythrocyte FA. These results indicate that erythrocyte FA may be a predictive biomarker for the increased prevalence of obesity, insulin resistance, leptin resistance, and risk of developing metabolic disorders.