Objective: To explore the inhibitory effect of water extract from pear pomace on abdominal fat accumulation and its underlying mechanism in high fat diet-fed animals. Methods: Three groups of male C57BL/6J mice were fed with a 60% kcal fat diet for 8 weeks. Pear pomace water extract (200 or 400 mg/kg body weight) was administered once daily via oral gavage. To confirm the possibility of the water extract of pear pomace acting as an activator of adenosine 5'-monophosphate-activated protein kinase (AMPK), differentiation of 3T3-L1 preadipocytes was induced in the presence of the water extract of pear pomace with or without compound C. Body weight, food efficacy ratio, insulin resistance, and adipogenic protein expression were measured. Moreover, in the 3T3-L1 cells, lipid content and lipogenesis-related proteins were measured using Oil Red O staining and Western blotting analysis. Results: Body weight gain and total abdominal fat weight were reduced in mice treated with pear pomace water extract. Pear pomace water extract reduced fasting blood glucose and insulin, thereby reducing the homeostatic model assessment of insulin resistance. It also resulted in dose-dependent decreases in triglyceride, total cholesterol, and low-density lipoprotein-cholesterol. The protein expression of p-AMPK increased, while the expression of AMPK-downstream proteins including PPAR-γ, C/EBPa, SREBP-1c, ACC, and FAS decreased in the adipose tissue of mice treated with pear pomace water extract. Furthermore, the inhibition of AMPK by compound C blocked pear pomace water extract-induced reduction of lipid content and the expression of lipogenesis-related genes. Conclusions: Pear pomace water extract prevents fat accumulation both in vivo and in vitro by activating AMPK.

PURPOSE: Helicobacter pylori infection induces phenotype-stabilizing methylation and promotes gastric mucosal atrophy that can inhibit CpG-island methylation. Relationship between the progression of gastric mucosal atrophy and the initiation of CpG-island methylation was analyzed to delineate epigenetic period for neoplastic transformation. MATERIALS AND METHODS: Normal-appearing gastric mucosa was biopsied from 110 H. pylori–positive controls, 95 H. pylori–negative controls, 99 gastric cancer patients, and 118 gastric dysplasia patients. Gastric atrophy was assessed using endoscopic-atrophic-border score. Methylation-variable sites of eight CpG-island genes adjacent to Alu (CDH1, ARRDC4, PPARG, and TRAPPC2L) or LTR (MMP2, CDKN2A, RUNX2, and RUNX3) retroelements and stomach-specific TFF3 gene were analyzed using radioisotope-labeled methylation-specific polymerase chain reaction. RESULTS: Mean ages of H. pylori–positive controls with mild, moderate, and severe atrophy were 51, 54, and 65 years and those of H. pylori–associated TFF3 overmethylation at the three atrophic levels (51, 58, and 63 years) tended to be periodic. Alu-adjacent overmethylation (50 years) was earlier than TFF3 overmethylation (58 years) in H. pylori–positive controls with moderate atrophy. Cancer patients with moderate atrophy showed late Alu-adjacent (58 years) overmethylation and frequent LTR-adjacent overmethylation. LTR-adjacent overmethylation was frequent in cancer (66 years) and dysplasia (68 years) patients with severe atrophy. CONCLUSION: Atrophic progression is associated with gastric cancer at moderate level by impeding the initiation of Alu-adjacent methylation. LTR-adjacent methylation is increased in cancer patients and subsequently in dysplasia patients.
Atrophy* ; DNA Methylation ; Epigenomics ; Gastric Mucosa ; Gastritis, Atrophic ; Genes, Essential* ; Helicobacter pylori ; Housekeeping* ; Humans ; Methylation* ; Polymerase Chain Reaction ; Retroelements ; Stomach Neoplasms*

BACKGROUND/OBJECTIVES: The anti-diabetic activity of pear through inhibition of α-glucosidase has been demonstrated. However, little has been reported about the effect of pear on insulin signaling pathway in obesity. The aims of this study are to establish pear pomace 50% ethanol extract (PPE)-induced improvement of insulin sensitivity and characterize its action mechanism in 3T3-L1 cells and high-fat diet (HFD)-fed C57BL/6 mice. MATERIALS/METHODS: Lipid accumulation, monocyte chemoattractant protein-1 (MCP-1) secretion and glucose uptake were measure in 3T3-L1 cells. Mice were fed HFD (60% kcal from fat) and orally ingested PPE once daily for 8 weeks and body weight, homeostasis model assessment of insulin resistance (HOMA-IR), and serum lipids were measured. The expression of proteins involved in insulin signaling pathway was evaluated by western blot assay in 3T3-L1 cells and adipose tissue of mice. RESULTS: In 3T3-L1 cells, without affecting cell viability and lipid accumulation, PPE inhibited MCP-1 secretion, improved glucose uptake, and increased protein expression of phosphorylated insulin receptor substrate 1 [p-IRS-1, (Tyr⁶³²)], p-Akt, and glucose transporter type 4 (GLUT4). Additionally, in HFD-fed mice, PPE reduced body weight, HOMA-IR, and serum lipids including triglyceride and LDL-cholesterol. Furthermore, in adipose tissue, PPE up-regulated GLUT4 expression and expression ratio of p-IRS-1 (Tyr⁶³²)/IRS, whereas, down-regulated p-IRS-1 (Ser³⁰⁷)/IRS. CONCLUSIONS: Our results collectively show that PPE improves glucose uptake in 3T3-L1 cells and insulin sensitivity in mice fed a HFD through stimulation of the insulin signaling pathway. Furthermore, PPE-induced improvement of insulin sensitivity was not accompanied with lipid accumulation.
3T3-L1 Cells ; Adipose Tissue ; Animals ; Blotting, Western ; Body Weight ; Cell Survival ; Chemokine CCL2 ; Diet, High-Fat ; Ethanol* ; Glucose ; Glucose Transport Proteins, Facilitative ; Glucose Transporter Type 4 ; Homeostasis ; Insulin Receptor Substrate Proteins ; Insulin Resistance* ; Insulin* ; Lipid Metabolism ; Mice ; Obesity ; Pyrus* ; Triglycerides

BACKGROUND/OBJECTIVES: In this study, the inhibitory effect of Erythronium japonicum extracts on the metastasis of MDA-MB-231 human breast cancer cell line was determined. MATERIALS/METHODS: Cells were cultured with DMSO or with 50, 75, 100 or 250 microg/ml of Erythronium japonicum methanol or ethanol extract. RESULTS: Both methanol and ethanol extracts significantly inhibited the growth and induced apoptosis of MDA-MB-231 cells in a dose-dependent manner. Erythronium japonicum extracts inhibited the adhesion of MDA-MB-231 cells. The invasion of breast cancer cells was suppressed by Erythronium japonicum extracts in a dose-dependent manner. The motility and MMP-2 and MMP-9 activities were also inhibited by both methanol and ethanol extracts. CONCLUSIONS: Our results collectively indicate that Erythronium japonicum extracts inhibit the growth, adhesion, migration and invasion as well as induce the apoptosis of human breast cancer cells. Clinical application of Erythronium japonicum as a potent chemopreventive agent may be helpful in limiting breast cancer invasion and metastasis.
Apoptosis ; Breast Neoplasms* ; Cell Line ; Dimethyl Sulfoxide ; Ethanol ; Humans ; Methanol ; Neoplasm Metastasis*

BACKGROUND AND OBJECTIVES: Salt-taste threshold can influence salt appetite, and is thought to be another marker of sodium intake. Many studies have found an association between sodium intake and blood pressure. The aim of this study was to compare the salt-taste threshold and salt intake between hypertensive and normotensive groups. SUBJECTS AND METHOD: One hundred twenty volunteers (51 men and 69 women) who did not take antihypertensive medications were evaluated. First, a questionnaire, which included questions regarding demographic information and preference of salty taste, was conducted, and 24-hour ambulatory blood pressure was checked. Then salt taste threshold was measured by assessing the ability of the subjects to discern the taste of salt in graded solutions of saline. Lastly, 24-hour urinary sodium was measured in a 24-hour urine collection. RESULTS: The salt taste threshold and taste preference for salt were slightly higher in hypertensive group. There was slightly higher salt intake measured as 24-hour urinary sodium in the hypertensive group, compared with the normotensive group. However, there were no significant differences in salt taste threshold, preference of salty taste, and salt intake between the normotensive and the hypertensive groups. CONCLUSION: The threshold of salt taste was not related to sodium intake and hypertension status. These results suggest that the development of hypertension depends on the complex interaction of factors such as genes and environmental factors rather than sensory factors like taste threshold and taste preference.
Appetite ; Blood Pressure ; Humans ; Hypertension ; Male ; Sodium ; Sodium Chloride ; Taste Threshold* ; Urine Specimen Collection ; Volunteers

BACKGROUND/OBJECTIVES: Cholecystokinin (CCK), a hormone or neuropeptide, is secreted in response to intraluminal nutrients by enteroendocrine I-cells of the intestine and has important physiological actions related to appetite regulation and satiety. The stimulation on CCK secretion from the intestine is of potential relevance for body weight management. Naringenin (4',5,7-trihydroxyflavanone) and its glycoside naringin (naringenin 7-rhamnoglucoside) have been reported to have many biological functions. In the current study, we investigated the question of whether naringenin and naringin could stimulate CCK secretion and then examined the mechanisms involved in CCK release. MATERIALS/METHODS: STC-1 cells were used as a model of enteroendocrine cells. CCK release and changes in intracellular Ca2+ ([Ca2+]i) were measured after incubation of cells with naringenin and naringin for 1 h. RESULTS: Naringenin caused significant (P < 0.05) stimulation of CCK secretion, but naringin did not. In addition, regarding the secretory mechanisms, naringenin-induced CCK secretion involved increases in [Ca2+]i, influx of extracellular Ca2+, at least in part, and activation of TRP channels, including TRPA1. CONCLUSION: Findings of this study suggest that naringenin could have a role in appetite regulation and satiety.
Appetite ; Appetite Regulation ; Body Weight ; Cholecystokinin* ; Enteroendocrine Cells ; Intestines ; Neuropeptides

Obesity occurs when a person's calorie intake exceeds the amount of energy burns, which may lead to pathologic growth of adipocytes and the accumulation of fat in the tissues. In this study, the effect and mechanism of pear pomace extracts on 3T3-L1 adipocyte differentiation and apoptosis of mature adipocytes were investigated. The effects of pear pomace extract on cell viability and the anti-adipogenic and proapoptotic effects were investigated via MTT assay, Oil red O staining, western blot analysis and apoptosis assay. 3T3-L1 preadipocytes were stimulated with DMEM containing 10% FBS, 0.5 mM 3-isobutyl-1-methylxanthine (IBMX), 5 microg/ml insulin and 1 microM dexamethasone for differentiation to adipocytes. 3T3-L1 cells were cultured with PBS or water extract of pear pomace. Water extract of pear pomace effectively inhibited lipid accumulations and expressions of PPAR-gamma and C/EBPalpha in 3T3-L1 cells. It also increased expression of p-AMPK and decreased the expression of SREBP-1c and FAS in 3T3-L1 cells. The induction of apoptosis was observed in 3T3-L1 cells treated with pear pomace. These results indicate that pear pomace water extract inhibits adipogenesis and induces apoptosis of adipocytes and thus can be used as a potential therapeutic substance as part of prevention or treatment strategy for obesity.
1-Methyl-3-isobutylxanthine ; 3T3-L1 Cells ; Adipocytes* ; Adipogenesis* ; Apoptosis* ; Blotting, Western ; Burns ; Cell Survival ; Dexamethasone ; Insulin ; Obesity ; Pyrus* ; Sterol Regulatory Element Binding Protein 1 ; Water*

BACKGROUND AND OBJECTIVES: The aim of the study was to compare the gustatory function between age-matched men and women in Korean subjects. SUBJECTS AND METHOD: Healthy non-smoking volunteers without smell and taste disorders were investigated. Thirty-nine men and women of the same age group were evaluated for gustatory function. Whole mouth taste test was performed with successive solutions of sucrose, sodium chloride, citric acid, and quinine hydrochloride. The electrical taste thresholds were measured using an electrogustometer for four different sites in the oral cavity, i.e., both sides of anterior and posterior tongue. RESULTS: Female subjects had lower mean values of detection and recognition thresholds for all of the four tastes than male subjects, although these results did not reach statistical significance except for the detection threshold for salt and the recognition threshold for quinine. In electrogustometry, thresholds in the posterior tongue of glossopharyngeal nerve area were significantly higher for men than women. CONCLUSION: Men had higher taste threshold than women of the same age category. For additional information on the effects of gender and aging on taste thresholds, further studies including a large number of well-controlled subjects are essential.
Aging ; Citric Acid ; Female ; Glossopharyngeal Nerve ; Humans ; Male ; Mouth ; Quinine ; Smell ; Sodium Chloride ; Sucrose ; Taste Disorders ; Taste Threshold* ; Tongue ; Volunteers

Hesperetin (3',5,7-trihydroxy 4'-methoxyflavanone) and its glycoside hesperidin (hesperetin 7-rhamnoglucoside) in oranges have been reported to possess pharmacological effects related to anti-obesity. However, hesperetin and hesperidin have not been studied on suppressive effects on appetite. This study examined that hesperetin and hesperidin can stimulate the release of cholecystokinin (CCK), one of appetite-regulating hormones, from the enteroendocrine STC-1 cells, and then examined the mechanisms involved in the CCK release. Hesperetin significantly and dose-dependently stimulated CCK secretion with an EC50 of 0.050 mM and increased the intracellular Ca2+ concentrations ([Ca2+]i) compared to the untreated control. The stimulatory effect by hesperetin was mediated via the entry of extracellular Ca2+ and the activation of TRP channels including TRPA1. These results suggest that hesperetin can be a candidate biomolecule for the suppression of appetite and eventually for the therapeutics of obesity.
Appetite ; Cholecystokinin* ; Citrus sinensis ; Enteroendocrine Cells ; Hesperidin ; Obesity

BACKGROUND AND OBJECTIVES: The sense of taste is one of the most important human senses and plays a critical role in an individual's food preferences and the nutritional status. Proper gustatory function in older people is important for quality of life and enjoyment of food. The objectives of this study was to investigate the effect of aging on taste thresholds in Korean subjects. SUBJECTS AND METHOD: One hundred sixty normal volunteers without smell and taste disorders were investigated. Each subject was given a questionnaire for age, sex, status of smoking and medication. Then, a whole mouth taste test was performed with successive solutions of sucrose, sodium chloride, citric acid, and quinine hydrochloride. RESULTS: Older subjects (over 50 years) showed worse taste sensitivity compared with younger subjects (age 20-29 years). The detection thresholds of all four basic tastes and the recognition threshold of salty taste of elderly participants were significantly higher than those of young participants. CONCLUSION: Gustatory sensitivity was found to decrease with age. Especially, older subjects appeared to have a reduced perception of salt, which can alter eating habits, such as intake of more salty foods. Our data can provide preliminary normative values for future investigation of chemosensation in the Korean population.
Aged ; Aging ; Citric Acid ; Eating ; Food Preferences ; Humans ; Mouth ; Nutritional Status ; Quality of Life ; Surveys and Questionnaires ; Quinine ; Smell ; Smoke ; Smoking ; Sodium Chloride ; Sucrose ; Taste Disorders ; Taste Threshold