Nutrition & Metabolism

Published by Springer Nature

Online ISSN: 1743-7075


Table 1 Baseline characteristics of the studied population (n = 1,178)
Table 2 Cross-sectional results of correlation between log-TBARS and various parameters by uni-and multi-variate analyses
Table 3 Longitudinal results of uni-and multi-variate analyses Correlation between one-year ΔTBARS and Δvalues of various parameters
Mean number of cardiovascular risk factors in the study population in relation to the log estimated visceral fat area (log-eVFA) and log-circulating thiobarbituric acid-reacting substance levels (log-TBARS). Each parameter was categorized into quartiles (Q1-Q4).
Relationship between circulating TBARS levels and body fat distribution. Subjects were divided according to body mass index (BMI) using a cutoff value of 25 kg/m2 and estimated visceral fat area (eVFA) using a cutoff value of 100 cm2, measured in 2006. Data are mean ± SEM. TBARS: thiobarbituric acid-reacting substance.
Cross-sectional and longitudinal study of association between circulating thiobarbituric acid-reacting substance levels and clinicobiochemical parameters in 1,178 middle-aged Japanese men - The Amagasaki Visceral Fat Study
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November 2011


169 Reads

Yukiyoshi Okauchi


Ken Kishida





Iichiro Shimomura
Circulating thiobarbituric acid-reacting substance (TBARS) levels, a marker of systemic oxidative stress, are predictive of cardiovascular events. However, they has not been evaluated in Japanese, especially with regard to the factors that contribute to the changes in circulating TBARS levels. We investigated the cross-sectional and longitudinal relationships between circulating TBARS levels and various clinicobiochemical parameters in middle-aged men. In this population-based study (The Amagasaki Visceral Fat Study), 1,178 Japanese male urban workers who had undergone health check-ups in 2006, 2007 and 2008 and were not on medications for metabolic disorders during the follow-up period, were enrolled. Serum TBARS levels were measured by the method of Yagi. The estimated visceral fat area (eVFA) by bioelectrical impedance was measured annually. After health check-ups, subjects received health education with lifestyle modification by medical personnel. The number of cardiovascular risk factors (hypertension, hyperglycemia, low HDL-C, hypertriglyceridemia, hyperuricemia, hyper-LDL-C and impaired renal function) augmented with the increases in log-eVFA (p < 0.0001) and log-TBARS (p < 0.0001). The combination of TBARS and eVFA had a multiplicative effect on risk factor accumulation (F value = 79.1, p = 0.0065). Stepwise multiple regression analysis identified log-eVFA, as well as age, log-body mass index (BMI), LDL-C, log-adiponectin, γ-glutamyl transpeptidase (γ-GTP) and uric acid as significant determinants of log-TBARS. Stepwise multiple regression analysis identified one-year changes in eVFA as well as BMI, γ-GTP and estimated glomerular filtration rate (eGFR) as significant determinants of one-year change in TBARS, and biennial changes in eVFA as well as BMI and γ-GTP, eGFR as significant determinants of biennial change in TBARS. The present study showed a significant cross-sectional and longitudinal correlation between TBARS and eVFA, as well as BMI and γ- GTP, eGFR. Visceral fat reduction may independently associate with the improvement in systemic ROS in middle-aged Japanese men. The Amagasaki Visceral Fat Study UMIN000002391.

Table 1 Fatty acid composition (% of total fatty acids) of control and experimental diets
Table 4 Fasting plasma lipid concentrations, glucose and insulin AUC after MTT and hepatic TG
Citrate synthase activity in liver, perirenal and inguinal adipose tissue. Values are mean ± SEM, n = 8. Means with different symbol are significantly different as compared to obese control; *P < 0.05, **P < 0.01, ***P < 0.001. Means with different letter are significantly different among control (lean and obese) and obese treated groups (CLA and VA+CLA). AT, adipose tissue.
Post-prandial triglyceride response following an oral fat challenge. Values are mean ± SEM, n = 4. AUC differ relative to obese rats fed the CD; bP < 0.05, cP < 0.001. iAUC differ relative to obese rats fed the CD; ***P < 0.001.
Effects of CLA and VA+CLA on hepatic protein abundance of lipogenic enzymes. Western blots of hepatic lipogenic enzymes (A), and relative abundance of ACC-1 (B) and FAS (C). Values are mean ± SEM, n = 8. Means with different symbol are significantly different as compared to obese rats fed the CD; *P < 0.05, **P < 0.01, ***P < 0.001. Means with different letter are significantly different among control (lean and obese) and obese treated groups (CLA and VA+CLA).
Increased hypolipidemic benefits of cis-9, trans-11 conjugated linoleic acid in combination with trans-11 vaccenic acid in a rodent model of the metabolic syndrome, the JCR:LA-cp rat

July 2010


203 Reads

Conjugated linoleic acid (cis-9, trans-11 CLA) and trans-11 vaccenic acid (VA) are found naturally in ruminant-derived foods. CLA has been shown to have numerous potential health related effects and has been extensively investigated. More recently, we have shown that VA has lipid-lowering properties associated with reduced hepatic lipidogenesis and chylomicron secretion in the JCR:LA-cp rat. The aim of this study was to evaluate potential additional hypolipidemic effects of purified forms of CLA and VA in an animal model of the metabolic syndrome (the JCR:LA-cp rat). Twenty four obese JCR:LA-cp rats were randomized and assigned to one of three nutritionally adequate iso-caloric diets containing 1% w/w cholesterol and 15% w/w fat for 16 wk: 1) control diet (CD), 2) 1.0% w/w cis-9, trans-11 CLA (CLA), 3) 1.0% w/w VA and 1% w/w cis-9, trans-11 CLA (VA+CLA). Lean rats were fed the CD to represent normolipidemic conditions. Fasting plasma triglyceride (TG), total cholesterol and LDL-cholesterol concentrations were reduced in obese rats fed either the CLA diet or the VA+CLA diet as compared to the obese control group (p < 0.05, p < 0.001; p < 0.001, p < 0.01; p < 0.01, p < 0.001, respectively). The VA+CLA diet reduced plasma TG and LDL-cholesterol to the level of the normolipidemic lean rats and further decreased nonesterified fatty acids compared to the CLA diet alone. Interestingly, rats fed the VA+CLA diet had a higher food intake but lower body weight than the CLA fed group (P < 0.05). Liver weight and TG content were lower in rats fed either CLA (p < 0.05) or VA+CLA diets (p < 0.001) compared to obese control, consistent with a decreased relative protein abundance of hepatic acetyl-CoA carboxylase in both treatment groups (P < 0.01). The activity of citrate synthase was increased in liver and adipose tissue of rats fed, CLA and VA+CLA diets (p < 0.001) compared to obese control, suggesting increased mitochondrial fatty acid oxidative capacity. We demonstrate that the hypolipidemic effects of chronic cis-9, trans-11 CLA supplementation on circulating dyslipidemia and hepatic steatosis are enhanced by the addition of VA in the JCR:LA-cp rat.

Study of the ketogenic agent AC-1202 in mild to moderate Alzheimer's disease: A randomized, double-blind, placebo-controlled, multicenter trial

September 2009


938 Reads

Alzheimer's disease (AD) is characterized by early and region-specific declines in cerebral glucose metabolism. Ketone bodies are produced by the body during glucose deprivation and are metabolized by the brain. An oral ketogenic compound, AC-1202, was tested in subjects with probable AD to examine if ketosis could improve cognitive performance. Daily administration of AC-1202 was evaluated in 152 subjects diagnosed with mild to moderate AD in a US-based, 90-day, randomized, double-blind, placebo-controlled, parallel-group study. Subjects were on a normal diet and continued taking approved AD medications. Primary cognitive end points were mean change from Baseline in the AD Assessment Scale-Cognitive subscale (ADAS-Cog), and global scores in the AD Cooperative Study - Clinical Global Impression of Change (ADCS-CGIC). AC-1202 was compared to Placebo in several population groups, including: intention-to-treat (ITT), per protocol, and dosage compliant groups. Results were also stratified by APOE4 carriage status (a predefined analysis based on the epsilon 4 (E4) variant of the apolipoprotein E gene). This trial was registered with, registry number NCT00142805, information available at AC-1202 significantly elevated a serum ketone body (beta-hydroxybutyrate) 2 hours after administration when compared to Placebo. In each of the population groups, a significant difference was found between AC-1202 and Placebo in mean change from Baseline in ADAS-Cog score on Day 45: 1.9 point difference, p = 0.0235 in ITT; 2.53 point difference, p = 0.0324 in per protocol; 2.6 point difference, p = 0.0215 in dosage compliant. Among participants who did not carry the APOE4 allele (E4(-)), a significant difference was found between AC-1202 and Placebo in mean change from Baseline in ADAS-Cog score on Day 45 and Day 90. In the ITT population, E4(-) participants (N = 55) administered AC-1202 had a significant 4.77 point difference in mean change from Baseline in ADAS-Cog scores at Day 45 (p = 0.0005) and a 3.36 point difference at Day 90 (p = 0.0148) compared to Placebo. In the per protocol population, E4(-) participants receiving AC-1202 (N = 37) differed from placebo by 5.73 points at Day 45 (p = 0.0027) and by 4.39 points at Day 90 (p = 0.0143). In the dosage compliant population, E4(-) participants receiving AC-1202 differed from placebo by 6.26 points at Day 45 (p = 0.0011, N = 38) and 5.33 points at Day 90 (p = 0.0063, N = 35). Furthermore, a significant pharmacologic response was observed between serum beta-hydroxybutyrate levels and change in ADAS-Cog scores in E4(-) subjects at Day 90 (p = 0.008). Adverse events occurred more frequently in AC-1202 subjects, were primarily restricted to the gastrointestinal system, and were mainly mild to moderate in severity and transient in nature. AC-1202 rapidly elevated serum ketone bodies in AD patients and resulted in significant differences in ADAS-Cog scores compared to the Placebo. Effects were most notable in APOE4(-) subjects who were dosage compliant.

Table 1 : Experimental Diets
Table 2 :
Chemical structure of canavanine and arginine
Survival of mice fed 15.7% dietary protein
Antinuclear Antibodies
Canavanine-induced longevity in mice may require diets with greater than 15.7% protein

March 2005


245 Reads

Dietary administration of 1% canavanine had been shown to improve survival in female BALB/c mice consuming diets containing 23.4% protein (dry matter basis). In order to determine if this effect also obtains at more moderate dietary protein concentrations, 30 female BALB/c mice were fed a basal diet with 14% protein (15.7% dry matter basis) and another 30 were fed the same diet plus 1% canavanine. Neither mean (Control 873.2 d, Canavanine 870.0 d; SEM = 34.2 d; P = 0.949 from ANOVA) nor median (Control 902 d, Canavanine 884.5 d; P = 0.9058 from Mann-Whitney) lifespans differed between groups. Although mean antinuclear antibody (ANA) titers did not differ between control and canavanine-treated mice at 833 days of age (19.84 vs 20.39 respectively; SEM = 2.64; P = 0.889 from ANOVA), one canavanine-treated mouse displayed an outlying ANA value of 50 (next lower value = 30) denoting possible early sign of incipient autoimmune disease in that individual. There may be an interaction between dietary protein level and canavanine with respect to lifespan in mice.

Effects of a Ketogenic diet on the quality of life in 16 patients with advanced cancer: A pilot trial

July 2011


1,610 Reads

Tumor patients exhibit an increased peripheral demand of fatty acids and protein. Contrarily, tumors utilize glucose as their main source of energy supply. Thus, a diet supplying the cancer patient with sufficient fat and protein for his demands while restricting the carbohydrates (CHO) tumors thrive on, could be a helpful strategy in improving the patients' situation. A ketogenic diet (KD) fulfills these requirements. Therefore, we performed a pilot study to investigate the feasibility of a KD and its influence on the quality of life of patients with advanced metastatic tumors. Sixteen patients with advanced metastatic tumors and no conventional therapeutic options participated in the study. The patients were instructed to follow a KD (less than 70 g CHO per day) with normal groceries and were provided with a supply of food additives to mix a protein/fat shake to simplify the 3-month intervention period. Quality of life [assessed by EORTC QLQ-C30 (version 2)], serum and general health parameters were determined at baseline, after every two weeks of follow-up, or after drop out. The effect of dietary change on metabolism was monitored daily by measuring urinary ketone bodies. One patient did not tolerate the diet and dropped out within 3 days. Among those who tolerated the diet, two patients died early, one stopped after 2 weeks due to personal reasons, one felt unable to stick to the diet after 4 weeks, one stopped after 6 and two stopped after 7 and 8 weeks due to progress of the disease, one had to discontinue after 6 weeks to resume chemotherapy and five completed the 3 month intervention period. These five and the one who resumed chemotherapy after 6 weeks report an improved emotional functioning and less insomnia, while several other parameters of quality of life remained stable or worsened, reflecting their very advanced disease. Except for temporary constipation and fatigue, we found no severe adverse side effects, especially no changes in cholesterol or blood lipids. These pilot data suggest that a KD is suitable for even advanced cancer patients. It has no severe side effects and might improve aspects of quality of life and blood parameters in some patients with advanced metastatic tumors.

Figure 1: The Bland-Altman analysis at baseline (panel A), after weight-loss (panel B) and for the Δ (before – after weight-loss) (panel C). The middle solid line represents the mean difference between %fat from ADP – %fat from DXA and the upper and lower dashed line represents ± 2 SD from the mean i.e. 95% limits of agreement (± 1.96 SD). Bias between the techniques was not observed, as indicated by a non-significant p value (p = 0.648, p = 0.408 and p = 0.665, respectively).
Table 1 : Subjects characteristic and body composition (n = 93).
Figure 2: The relationships between the ΔADP and ΔDXA for %fat, fat mass (kg), and fat free mass (kg) are depicted in the scatter plots (A, B, and C, respectively).
Table 2 : Summary of regression and Bland-Altman analysis before and after weight-loss compared to DXA
Validity of air-displacement plethysmography in the assessment of body composition changes in a 16-month weight loss program

August 2006


118 Reads

To compare the accuracy of air displacement plethysmography (ADP) and dual energy x-ray absorptionmetry (DXA) in tracking changes in body composition after a 16 month weight loss intervention in overweight and obese females. 93 healthy female subjects (38.9 +/- 5.7 yr, 159.8 +/- 5.6 cm, 76.7 +/- 9.9 kg, 30.0 +/- 3.4 kg/m2) completed a 16 month weight loss intervention. Eligible subjects attended 15 treatment sessions occurring over the course of 4 months with educational content including topics relating to physical activity and exercise, diet and eating behavior, and behavior modification. In the remaining 12 months, subjects underwent a lifestyle program designed to increase physical activity and improve eating habits. Before and after the intervention, subjects had their percent body fat (%fat), fat mass (FM), and fat-free mass (FFM)) assessed by DXA and ADP. Significant differences (p < or = 0.001) were found between DXA and ADP at baseline %fat (46.0 % fat vs. 42.0 % fat), FM (35.3 kg vs. 32.5 kg) and FFM (40.8 kg vs. 44.2 kg) as well as at post intervention for %fat (42.1% fat vs. 38.3 % fat), FM (30.9 kg vs. 28.4 kg) and FFM (41.7 kg vs. 44.7 kg). At each time point, ADP %fat and total FM was significantly lower (p < or = 0.001) than DXA while FFM was significantly higher (p < or = 0.001). However, both techniques tracked %fat changes similarly considering that there were no differences between the two means. Furthermore, a Bland-Altman analysis was performed and no significant bias was observed, thus demonstrating the ability of ADP to measure body fat across a wide range of fatness. At baseline and post weight loss, a significant difference was found between ADP and DXA. However, the results indicate both methods are highly related and track changes in %fat similarly after a weight loss program in overweight and obese females. Additionally, the mean changes in %fat were similar between the two techniques, suggesting that ADP can be translated to its use in clinical practice and research studies as DXA currently is used.

Circulating interleukin-18: A specific biomarker for atherosclerosis-prone patients with metabolic syndrome

January 2011


112 Reads

Metabolic syndrome (MetS) is associated with an increased risk of the development of atherosclerotic cardiovascular disease (CVD). Interleukin-18 (IL-18), which is a pleiotropic proinflammatory cytokine with important regulatory functions in the innate immune response system, plays a crucial role in vascular pathologies. IL-18 is also a predictor of cardiovascular death in patients with CVD and is involved in atherosclerotic plaque destabilization. In order to determine if circulating levels of IL-18 can serve as a specific biomarker for distinguishing MetS patients from pre-MetS subjects, we studied 78 patients with visceral fat deposition and 14 age-matched control subjects. Increased levels of IL-18 were observed more frequently in patients with MetS than in pre-MetS subjects and were positively associated with waist circumference. Serum levels of IL-18 were significantly reduced by a change in weight caused by lifestyle modifications. There was a significant interaction between waist circumference and serum IL-18 concentration. Weight loss of at least 5% of the body weight caused by lifestyle modification decreased IL-18 circulating levels relative to the reduction in waist circumference and blood pressure, suggesting that this degree of weight loss benefits the cardiovascular system. IL-18 may be a useful biomarker of the clinical manifestations of MetS and for the management of the risk factors of CVD.

Mitigating preventable chronic disease: Progress report of the Cleveland Clinic's Lifestyle 180 program

November 2011


316 Reads

Poor lifestyle choices are key in development and progression of preventable chronic diseases. The purpose of the study was to design and test a program to mitigate the physical and fiscal consequences of chronic diseases. Here we report the outcomes for 429 participants with one or more chronic conditions, including obesity, hypertension, hyperlipidemia and diabetes mellitus, many of whom had failed traditional disease management programs, who enrolled into a comprehensive lifestyle intervention. The Lifestyle 180 program integrates nutrition, physical activity and stress management interventions and was conducted at the Wellness Institute of the Cleveland Clinic, United States. An intensive 6 week immersion course, with 8 hours of group instruction per week, was followed by 3 follow-up, 4 hour-long sessions over the course of 6 months. Changes in biometric (weight, height, waist circumference, resting heart rate and blood pressure) and laboratory variables (fasting lipid panel, blood glucose, insulin, hemoglobin A1c, ultra sensitive C-reactive protein) at 6 months were compared with baseline (pre-post analysis). At week 30, biometric and laboratory data were available for 244 (57%) and 299 (70%) participants, respectively. These had a mean ± SD reduction in weight (6.8 ± 6.9 kg, P < 0.001), waist circumference (6.1 ± 7.3 cm, P < 0.001), glucose (4.5 ± 29.6 mg/dL or 0.25 ± 1.64 mmol/L, P = 0.009), triglycerides (26.4 ± 58.5 mg/dL or 0.30 ± 0.66 mmol/L, P < 0.001), low-density lipoprotein cholesterol (LDL) (7.9 ± 25.1 mg/dL or 0.2 ± 0.65 mmol/L, P < 0.001), hemoglobin A1c (HgbA1c) (0.20 ± 0.64%, P = 0.001), insulin (3.8 ± 11 microU/ml or 26.6 ± 76.4 ρmol, P < 0.001) and ultra sensitive C-reactive protein (US - CRP) (0.9 ± 4.8 mg/dL or 7.3 ± 40.2 nmol/L, P = 0.012), an increase in mean high-density lipoprotein cholesterol (HDL) (3.7 ± 8.4 mg/dL or 0.1 ± 0.22, P < 0.001), and decreased use of medications. Implementation of a comprehensive lifestyle modification program among adults with common chronic conditions results in significant and clinically meaningful improvements in biometric and laboratory outcomes after 6 months.

Table 1 Patients' baseline data before KEN (n = 19,036)
6-French polyurethane tubes are almost invisible and very well tolerated.
Ketogenic enteral nutrition as a treatment for obesity: Short term and long term results from 19,000 patients

October 2012


466 Reads

Background Only protein diet has been used successfully to prevent loss of lean body mass first in post-surgical and then in obese patients. We studied overweight and obese patients receiving short treatments of an exclusively protein-based nutritional solution as 24-hour enteral infusion. Methods 19,036 patients (age 44.3 ± 13, M:F = 2:5) with an initial body mass index of 36.5 ± 7.1 underwent 10-day cycles of enteral nutrition through a fine nasogastric tube. The nutritional solution consisted solely of 50–65 g of proteins, plus vitamins and electrolytes. The 24-hour infusion was controlled with a small portable pump. Before and after each 10-day cycle body composition was checked with a Handy 3000 impedance analyzer. At the onset of treatment, average fat mass was 40.9 ± 12.8 kg while body cell mass was 42.7 ± 7.2 kg in males and 27.4 ± 4.6 kg in females. Results After an average of 2.5 cycles the patients lost 10.2 ± 7.0 kg of body weight, 5.8 ± 5.5 kg of fat mass and 2.2 ± 3.3 kg of body cell mass. No significant adverse effects were recorded except asthenia and constipation which were easily controlled with therapy. Long-term results were obtained from 15,444 patients and after an average of 362 ± 296 days we found a mean weight regain of 15.4%. Conclusion Ketogenic Enteral Nutrition treatment of over 19,000 patients induced a rapid 10% weight loss, 57% of which was Fat Mass. No significant adverse effects were found. The treatment is safe, fast, inexpensive and has good one-year results for weight maintenance.

Table 1 : Select physiologic variables by fasting plasma glucose status among 3,485 U.S. adults (≥ 20y) with no self-reported diabetes. 
Age and kidney function are the primary correlates of fasting plasma total homocysteine levels in non-diabetic and diabetic adults. Results from the 1999–2002 National Health and Nutrition Examination Survey

June 2005


37 Reads

Plasma total homocysteine (tHcy) is commonly elevated in persons with diabetes. This may be due to effects of insulin and/or glucose and/or metabolic control on the metabolism or plasma levels of tHcy. This study examined the effects of fasting plasma glucose status on fasting tHcy levels among adults without diabetes, and diabetes per se among adults with a self-report history of diabetes. Analysis of data on adults (> or = 20y) who had fasted at least 8 hours, from the National Health and Nutrition Examination Survey (1999-2000 and 2001-2002). Subjects with no self-report history of diabetes were grouped according to fasting plasma glucose status as normal (< 100 mg/dL = NFG, n = 2,244), impaired (> or = 100 < 126 mg/dL = IFG, n = 1,108), or a provisional diagnosis of diabetes (> or = 126 mg/dL = DFG, n = 133). Subjects with a self-report history of diabetes (n = 275) were examined separately. Fasting tHcy was higher (Ps < 0.01) among non-diabetic subjects with DFG and IFG, compared to NFG (median [95% confidence interval] = 8.6 [8.0-9.2], 8.3 [8.1-8.5], and 7.4 [7.3-7.5] micromol/L, respectively). Diabetic subjects had levels similar to non-diabetic subjects with DFG and IFG (8.3 [7.9-8.6] micromol/L). Age and estimated creatinine clearance were strong correlates of fasting tHcy among non-diabetic subjects (r = 0.38 to 0.44 and r = -0.35 to -0.46, respectively) and diabetic subjects (r = 0.41 and r = -0.46, respectively) (Ps < 0.001), while fasting glucose and glycohemoglobin (HbA1c) were weaker (but still significant) correlates of tHcy in non-diabetic and diabetic subjects. Fasting glucose status was not a significant independent predictor of fasting tHcy levels in non-diabetic subjects, and HbA1c was not a significant independent predictor of tHcy in diabetic subjects (Ps > 0.05). Fasting tHcy levels are elevated among non-diabetic adults with elevated fasting glucose levels, compared to persons with normal fasting glucose levels, and among diabetic adults. However, elevations in fasting tHcy appear to be mediated primarily by age and kidney function, and not by measures of glucose metabolism.

Table 2 Body weight, weight gain, relative liver weight of control and experimental rats
Malondialdehyde (MDA) and conjugated dienes (CD) levels in liver of rat treated or not with 2,4-D under effects of supplemented extra virgin olive oil (EVOO) and its fractions (OOHF and OOLF). C: controls group, D: 2, 4-D treated group, D/EVOO: 2, 4-D + extra virgin olive oil, D/OOHF: 2, 4-D+ hydrophilic fraction, D/OOLF: 2,4-D+ lipophilic fraction, EVOO: extra virgin olive oil treated group alone, OOHF: group treated with hydrophilic fraction of olive oil, OOLF: group treated with lipophilic fraction of olive oil. Data are expressed as means ± SD (n = 10 rats per group). Comparison between groups was made using unpaired Student t test. * p < .05 vs 2,4-D group; § p < .05 vs control group.
Effects of olive oil and its fractions on oxidative stress and the liver's fatty acid composition in 2,4-Dichlorophenoxyacetic acid-treated rats

October 2010


361 Reads

Olive oil's beneficial effects are not only related to its high content of oleic acid, but also to the antioxidant potential of its polyphenols. In this study, we assess the effects of virgin olive oil and its fractions on 2,4-D- induced oxidative damage in the liver of rats. Male Wistar rats were randomly divided into eight groups of ten each: (C) a control group, (D) group that received 2,4-D (5 mg/kg b.w.), (D/EVOO) group treated with 2,4-D plus extra virgin olive oil, (D/OOHF) group that received 2,4-D plus hydrophilic fraction, (D/OOLF) group treated with 2,4-D plus lipophilic fraction, (EVOO) group that received only extra virgin olive oil, (OOHF) group given hydrophilic fraction and (OOLF) group treated with lipophilic fraction. These components were daily administered by gavage for 4 weeks. A significant liver damage was observed in rats treated with 2,4-D via increased serum levels of transaminases and alkaline phosphatase, hepatic lipid peroxidation and decreased hepatic antioxidant enzyme activities, namely, superoxide dismutase, catalase, glutathione peroxidase, and glutathione reductase. The liver's fatty acid composition was also significantly modified with 2,4-D exposure. However, extra virgin olive oil and hydrophilic fraction intake during 2,4-D treatment induced a significant increase in the antioxidant enzyme activities and a decrease in the conjugated dienes (CD) and thiobarbituric acid-reactive substances (TBARs) levels in the liver. The lipophilic fraction supplemented to 2,4-D- treated rats did not show any improvement in the liver oxidative status while a marked improvement was detected in the hepatic fatty acid composition of rats supplemented with olive oil and the two fractions. We concluded that the protective effect of olive oil against oxidative damage induced by 2,4-D is mainly related to the antioxidant potential of its hydrophilic fraction.

Table 1 Daily energy and fatty acids intakes and percentage contribution to energy of Mexican school-age children and adolescents
Table 2 Daily energy and fatty acids intakes and percentage contribution to energy of Mexican adults and adults older than 60 years
Proportion of school-age children (A) and adolescents (B) as by their degree of adequacy in the intake of fatty acid classes. Stratification for TFA and PUFA: I) Adequate intake, when the intake/recommendation ratio was equal to 1; II) Insufficiently inadequate intake when the intake/recommendation ratio was < 1; and III) Excessively inadequate intake when the intake/recommendation ratio was > 1. Dietary adequacy for saturated and trans fatty acids (TrFA) was stratified into the following two categories: I) Adequate intake, when the intake/recommendation ratio was equal to 1; II) Inadequate intake when the intake/recommendation ratio was > 1.
Proportion of adults (A) and adults older than 60 years (B) as by their degree of adequacy in the intake of fatty acid classes. Stratification for TFA and PUFA: I) Adequate intake, when the intake/recommendation ratio was equal to 1; II) Insufficiently inadequate intake when the intake/recommendation ratio was < 1; and III) Excessively inadequate intake when the intake/recommendation ratio was > 1. Dietary adequacy for saturated and trans fatty acids (TrFA) was stratified into the following two categories: I) Adequate intake, when the intake/recommendation ratio was equal to 1; II) Inadequate intake when the intake/recommendation ratio was > 1.
Distribution of the Mexican population according to the fulfilment of recommendations of balanced intake of Omega6/Omega3. Dietary adequacy for n-3 and n-6 fatty acids was defined by its compliance with the recommended n-6/n-3 ratios, ranging 5:1 to 10:1 [35].
Fatty acids intake in the Mexican population. Results of the National Nutrition Survey 2006

June 2011


298 Reads

There is growing evidence that quality, rather that quantity of fat is the determinant of cardiovascular risk. The objective of the study is to describe quantitatively the intake and adequacy of fatty acid classes among the Mexican population aged 5-90 years from a probabilistic survey. Dietary intake of individual and classes of fatty acids was computed from the dataset of the 2006 Mexican National Health and Nutrition Survey (ENSANUT2006), collected by a food frequency questionnaire. Adequacy was calculated in reference to authoritative recommendations. The mean intake of total fatty acids (TFA ≈ 25%E) fell within WHO recommendations; the intakes of saturated fatty acids (SFA) among all age-groups (45-60%) and of trans fatty acids (TrFA) in 30% of school-age children and adolescents and 20% of adults exceeded international recommendations. The mean intake of polyunsaturated fatty acids (PUFA) and particularly of n6 and n3 PUFAS, was inadequately insufficient in 50% of the sample. The main public health concerns are the high intake of SFA and the suboptimal intake of PUFA in Mexican population. The TrFA intake represents a low public health risk.

The optimal cut point of homeostasis model assessment (HOMA) for diagnosis of metabolic syndrome. The diagnostic criteria for metabolic syndrome are those recommended by the international diabetes federation (IDF) (left) and Adult Treatment Panel III (ATP III) (right). The top panels (A) show the results in non-diabetic individuals and the bottom panels (B) refer to diabetic individuals.
Positive likelihood ratios of different HOMA-IR percentiles for prediction of IDF- and ATPIII-defined metabolic syndrome. The results in non-diabetic and diabetic individuals are shown in the left and right panels, respectively.
Optimal cut-off of homeostasis model assessment of insulin resistance (HOMA-IR) for the diagnosis of metabolic syndrome: Third national surveillance of risk factors of non-communicable diseases in Iran (SuRFNCD-2007)

April 2010


408 Reads

We have recently determined the optimal cut-off of the homeostatic model assessment of insulin resistance for the diagnosis of insulin resistance (IR) and metabolic syndrome (MetS) in non-diabetic residents of Tehran, the capital of Iran. The aim of the present study is to establish the optimal cut-off at the national level in the Iranian population with and without diabetes. Data of the third National Surveillance of Risk Factors of Non-Communicable Diseases, available for 3,071 adult Iranian individuals aging 25-64 years were analyzed. MetS was defined according to the Adult Treatment Panel III (ATPIII) and International Diabetes Federation (IDF) criteria. HOMA-IR cut-offs from the 50th to the 95th percentile were calculated and sensitivity, specificity, and positive likelihood ratio for MetS diagnosis were determined. The receiver operating characteristic (ROC) curves of HOMA-IR for MetS diagnosis were depicted, and the optimal cut-offs were determined by two different methods: Youden index, and the shortest distance from the top left corner of the curve. The area under the curve (AUC) (95%CI) was 0.650 (0.631-0.670) for IDF-defined MetS and 0.683 (0.664-0.703) with the ATPIII definition. The optimal HOMA-IR cut-off for the diagnosis of IDF- and ATPIII-defined MetS in non-diabetic individuals was 1.775 (sensitivity: 57.3%, specificity: 65.3%, with ATPIII; sensitivity: 55.9%, specificity: 64.7%, with IDF). The optimal cut-offs in diabetic individuals were 3.875 (sensitivity: 49.7%, specificity: 69.6%) and 4.325 (sensitivity: 45.4%, specificity: 69.0%) for ATPIII- and IDF-defined MetS, respectively. We determined the optimal HOMA-IR cut-off points for the diagnosis of MetS in the Iranian population with and without diabetes.

A 21-day Daniel fast with or without krill oil supplementation improves anthropometric parameters and the cardiometabolic profile in men and women

September 2012


95 Reads

The Daniel Fast is a vegan diet that prohibits the consumption of animal products, refined foods, white flour, preservatives, additives, sweeteners, flavorings, caffeine, and alcohol. Following this dietary plan for 21 days has been demonstrated to improve blood pressure, LDL-C, and certain markers of oxidative stress, but it has also been shown to lower HDL-C. Krill oil supplementation has been shown to increase HDL-C. We investigated the effects of following a Daniel Fast dietary plan with either krill oil supplementation (2 g/day) or placebo supplementation (coconut oil; 2 g/day) for 21 days. The subjects in this study (12 men and 27 women) were heterogeneous with respect to body mass index (BMI) (normal weight, overweight, and obese), blood lipids (normolipidemic and hyperlipidemic), blood glucose (normal fasting glucose, impaired fasting glucose, and type 2 diabetic), and blood pressure (normotensive and hypertensive). Krill oil supplementation had no effect on any outcome measure (all p > 0.05), and so the data from the krill oil group and the placebo group were collapsed and analyzed to examine the effects of following a 21-day Daniel Fast. Significant reductions were observed in LDL-C (100.6 ± 4.3 mg/dL vs. 80.0 ± 3.7 mg/dL), the LDL:HDL ratio (2.0 ± 0.1 vs. 1.7 ± 0.1), fasting blood glucose (101.4 ± 7.5 mg/dL vs. 91.7 ± 3.4 mg/dL), fasting blood insulin (7.92 ± 0.80 μU/mL vs. 5.76 ± 0.59 μU/mL), homeostasis model assessment of insulin resistance (HOMA-IR) (2.06 ± 0.30 vs. 1.40 ± 0.21), systolic BP (110.7 ± 2.2 mm Hg vs. 105.5 ± 1.7 mm Hg), and body weight (74.1 ± 2.4 kg vs. 71.5 ± 2.3 kg) (all p < 0.05). Following a Daniel Fast dietary plan improves a variety of cardiometabolic parameters in a wide range of individuals in as little as 21 days, and these improvements are unaffected by krill oil supplementation. Trial registration

Table 1 Subject baseline characteristics
Table 2 Medication usage of subjects
Table 3 Dietary data of men and women before and during the final seven days of a 21 day Daniel Fast
Plasma malondialdehyde (A) and plasma hydrogen peroxide (B) of men and women before and after a 21 day Daniel Fast. Values are mean ± SEM.
Serum Trolox Equivalent Antioxidant Capacity (A), serum Oxygen Radical Absorbance Capacity (B), and plasma nitrate/nitrite (C) of men and women before and after a 21 day Daniel Fast. Values are mean ± SEM.
A 21 day Daniel Fast improves selected biomarkers of antioxidant status and oxidative stress in men and women

March 2011


265 Reads

Dietary modification via both caloric and nutrient restriction is associated with multiple health benefits, some of which are related to an improvement in antioxidant status and a decrease in the production of reactive oxygen species. The Daniel Fast is based on the Biblical book of Daniel, is commonly partaken for 21 days, and involves food intake in accordance with a stringent vegan diet. The purpose of the present study was to determine the effect of a 21 day Daniel Fast on biomarkers of antioxidant status and oxidative stress. 43 subjects (13 men; 30 women; 35 ± 1 yrs; range: 20-62 yrs) completed a 21 day Daniel Fast following the guidelines provided by investigators. Subjects reported to the lab in a 12 hour post-absorptive state both pre fast (day 1) and post fast (day 22). At each visit, blood was collected for determination of malondialdehyde (MDA), hydrogen peroxide (H2O2), nitrate/nitrite (NOx), Trolox Equivalent Antioxidant Capacity (TEAC), and Oxygen Radical Absorbance Capacity (ORAC). Subjects recorded dietary intake during the 7 day period immediately prior to the fast and during the final 7 days of the fast. A decrease was noted in MDA (0.66 ± 0.0.03 vs. 0.56 ± 0.02 μmol L-1; p = 0.004), while H2O2 demonstrated a trend for lowering (4.42 ± 0.32 vs. 3.78 ± 0.21 μmol L-1; p = 0.074). Both NOx (18.79 ± 1.92 vs. 26.97 ± 2.40 μmol L-1; p = 0.003) and TEAC (0.47 ± 0.01 vs. 0.51 ± 0.01 mmol L-1; p = 0.001) increased from pre to post fast, while ORAC was unchanged (5243 ± 103 vs. 5249 ± 183 μmol L-1 TE; p = 0.974). As expected, multiple differences in dietary intake were noted (p < 0.05), including a reduction in total calorie intake (2185 ± 94 vs. 1722 ± 85). Modification of dietary intake in accordance with the Daniel Fast is associated with an improvement in selected biomarkers of antioxidant status and oxidative stress, including metabolites of nitric oxide (i.e., NOx).

Individual changes in bodyweight in 16 obese patients with type 2 diabetes. The patients at start changed from a high-carbohydrate diet to a diet consisting of 20 % carbohydrates, 30 % protein and 50 % fat.
Percentage changes in HbA1c and bodyweight in 16 obese patients with type 2 diabetes. The figures are plotted 3 months after a change to a 20 % carbohydrate diet at which time the reduction in HbA1c was most pronounced.
Low-carbohydrate diet in type 2 diabetes. Stable improvement of bodyweight and glycemic control during 22 months follow-up

February 2006


163 Reads

Low-carbohydrate diets in the management of obese patients with type 2 diabetes seem intuitively attractive due to their potent antihyperglycemic effect. We previously reported that a 20% carbohydrate diet was significantly superior to a 55-60% carbohydrate diet with regard to bodyweight and glycemic control in 2 non-randomised groups of obese diabetes patients observed closely over 6 months. The effect beyond 6 months of reduced carbohydrate has not been previously reported. The objective of the present study, therefore, was to determine to what degree the changes among the 16 patients in the low-carbohydrate diet group at 6-months were preserved or changed 22 months after start, even without close follow-up. In addition, we report that, after the 6 month observation period, two thirds of the patients in the high-carbohydrate changed their diet. This group also showed improvement in bodyweight and glycemic control. Retrospective follow-up of previously studied subjects on a low carbohydrate diet. The mean bodyweight at the start of the initial study was 100.6 +/- 14.7 kg. At six months it was 89.2 +/- 14.3 kg. From 6 to 22 months, mean bodyweight had increased by 2.7 +/- 4.2 kg to an average of 92.0 +/- 14.0 kg. Seven of the 16 patients (44%) retained the same bodyweight from 6 to 22 months or reduced it further; all but one had lower weight at 22 months than at the beginning. Initial mean HbA1c was 8.0 +/- 1.5%. After 6 and 12 months it was 6.6 +/- 1.0 % and 7.0 +/- 1.3%, respectively. At 22 months, it was still 6.9 +/- 1.1%. Advice on a 20% carbohydrate diet with some caloric restriction to obese patients with type 2 diabetes has lasting effect on bodyweight and glycemic control.

Table 1 Weight/cell content of three main WAT sites of overweight male rats treated for 10 days with combined OE and B3A
Body weight and food intake changes in overweight rats treated with OE and/or B3A during the 10-day study. The data are the mean ± sem of six different animals.
P values for the statistical significance of the effects of OE and B3A on the gene expression of lipid metabolism -related enzymes and factors in the main sites of WAT of male overweight rats treated with OE and a B3A (two-way ANOVA). Data in bold red italics represent significant decreases in the combined specific mRNA content in the given WAT site (and, in the case of "combined WAT" in the sum of all three sites) compared with controls receiving vehicle only. Data in bold green represent significant increases. Non-significant effects (NS) are in black. An asterisk * in the interaction (int) column denotes a significant (P < 0.05) interaction between OE and B3A effects.
Combined WAT (i.e. subcutaneous inguinal, epididymal and retroperitoneal) content of UCP1 gene mRNA in overweight rats treated with OE and/or B3A for 10 days. The data are the mean ± sem of six different animals. Statistical significance of the differences between groups: asterisk = p < 0.05 versus controls; black circle = p < 0.05 OE versus B3A and B3A+OE; no significant differences were found between B3A and B3A+OE.
Comparative effects of oleoyl-estrone and a specific 3- adrenergic agonist (CL316, 243) on the expression of genes involved in energy metabolism of rat white adipose tissue

February 2010


60 Reads

The combination of oleoyl-estrone (OE) and a selective beta3-adrenergic agonist (B3A; CL316,243) treatment in rats results in a profound and rapid wasting of body reserves (lipid). In the present study we investigated the effect of OE (oral gavage) and/or B3A (subcutaneous constant infusion) administration for 10 days to overweight male rats, compared with controls, on three distinct white adipose tissue (WAT) sites: subcutaneous inguinal, retroperitoneal and epididymal. Tissue weight, DNA (and, from these values cellularity), cAMP content and the expression of several key energy handling metabolism and control genes were analyzed and computed in relation to the whole site mass. Both OE and B3A significantly decreased WAT mass, with no loss of DNA (cell numbers). OE decreased and B3A increased cAMP. Gene expression patterns were markedly different for OE and B3A. OE tended to decrease expression of most genes studied, with no changes (versus controls) of lipolytic but decrease of lipogenic enzyme genes. The effects of B3A were widely different, with a generalized increase in the expression of most genes, including the adrenergic receptors, and, especially the uncoupling protein UCP1. OE and B3A, elicit widely different responses in WAT gene expression, end producing similar effects, such as shrinking of WAT, loss of fat, maintenance of cell numbers. OE acted essentially on the balance of lipolysis-lipogenesis and the blocking of the uptake of substrates; its decrease of synthesis favouring lipolysis. B3A induced a shotgun increase in the expression of most regulatory systems in the adipocyte, an effect that in the end favoured again the loss of lipid; this barely selective increase probably produces inefficiency, which coupled with the increase in UCP1 expression may help WAT to waste energy through thermogenesis. There were considerable differences in the responses of the three WAT sites. OE in general lowered gene expression and stealthily induced a substrate imbalance. B3A increasing the expression of most genes enhanced energy waste through inefficiency rather than through specific pathway activation. There was not a synergistic effect between OE and B3A in WAT, but their combined action increased WAT energy waste.

Oral administration of Lactobacillus reuteri GMNL-263 improves insulin resistance and ameliorates hepatic steatosis in high fructose-fed rats

April 2013


498 Reads

Background Type 2 diabetes mellitus (DM), characterized by peripheral insulin resistance, is the most common form of diabetes. Probiotics are live micro-organisms that, when administered in adequate amounts, confer delaying effect on DM development. In this study, the effects Lactobacillus reuteri GMNL-263 (Lr263), a new probiotic strain developed by our laboratory, on insulin resistance and the development of hepatic steatosis in high-fructose fed rats were explored. Furthermore, the relevant regulatory pathways involved were also investigated. Method Male Sprague–Dawley rats were fed a high-fructose diet with or without Lr263 administration for 14 weeks. The composition of fecal microbiota, oral glucose tolerance, glycated haemoglobin, insulin, leptin, C-peptide, and incretins were measured. The markers of liver injury, serum and hepatic lipids profile, activity of hepatic antioxidant enzyme, and proinflammatory cytokines in adipose tissue were investigated. Additionally, the expression of hepatic lipogenic genes and insulin signaling related genes in adipose tissue were also studied. Liver sections were examined for hepatic steatosis using hematoxylin-eosin staining. Results The levels of serum glucose, insulin, leptin, C-peptide, glycated hemoglobin, GLP-1, liver injury markers, lipid profile in serum and liver were significantly increased in high-fructose-fed rats. However, after Lr263 administration, the elevation of these parameters was significantly suppressed. Feeding of Lr263 reversed the decreased number of bifidobacterium species and lactobacillus species and increased number of clostridium species induced by high fructose treatment. The decreased activities of hepatic antioxidant enzymes in HFD rats were dramatically reversed by Lr263 treatment. Concentrations of IL-6 and TNF-α in adipose tissue which were elevated in high fructose treatment were markedly decreased after Lr263 feeding. Decreased levels of PPAR-γ and GLUT4 mRNA after high fructose treatment were significantly enhanced by Lr263 administration. Lr263 consumption normalized the increased lipogenic gene (Srebp-1c, FAS, and Elvol6) expressions stimulated by high fructose. Administration of Lr263 significantly ameliorated hepatic steatosis observed in high fructose treated rats. Conclusion Our study provided evidences clarifying the effectiveness of Lr263 on reducing insulin resistance as well as hepatic steatosis formation in high-fructose-fed rats and suggested that Lr263 may be a promising therapeutic agent in treating type 2 diabetes.

Table 1 Dietary caloric and macronutrient intake for the CARB and NOSS groups 
Table 2 Body composition and muscle strength variables for the CARB and NOSS groups 
Table 3 Serum and muscle markers indicative of muscle protein synthesis for the CARB and NOSS groups 
Table 4 Serum clinical chemistry markers for the CARB and NOSS groups 
Table 5 Whole blood clinical chemistry markers for the CARB and NOSS groups 
Effects of 28 days of resistance exercise while consuming commercially available pre- and post-workout supplements, NO-Shotgun (R) and NO-Synthesize (R) on body composition, muscle strength and mass, markers of protein synthesis, and clinical safety markers in males

November 2011


479 Reads

The effects of 28 days of heavy resistance training while ingesting the pre- and post-workout supplements, NO-Shotgun® and NO-Synthesize® were determined on body composition, muscle strength and mass, markers of protein synthesis, and clinical safety markers. Nineteen non-resistance-trained males participated in a resistance training program 4 times/week for 28 days while either ingesting 27 g/day of carbohydrate (CARB) or NO-Shotgun® 30 min pre-exercise and 27 g/day of carbohydrate or NO- Synthesize® 30 min post-exercise (NOSS). Data were analyzed with separate 2 × 2 ANOVA (p < 0.05). Total body mass was increased in both groups (p = 0.001), but not different between groups. Fat mass was unchanged with CARB, but NOSS decreased fat mass (p = 0.026). Both groups increased fat-free mass (p = 0.001); however, the increases were greater with NOSS (p = 0.023). NOSS underwent greater increases in upper-body (p = 0.023) and lower-body (p = 0.035) strength than CARB. Myofibrillar protein significantly increased in both groups (p = 0.041), with NOSS being greater than CARB (p = 0.049). All of the MHC isoforms were significantly increased in both groups; however, NOSS was greater than CARB for MHC 1 (p = 0.013) and MHC 2A (p = 0.046). All of the myogenic regulatory factors were significantly increased in both groups; however, NOSS was greater than CARB for Myo-D (p = 0.038) and MRF-4 (p = 0.001). For the whole blood and serum clinical chemistry markers, all variables remained within normal clinical ranges. Heavy resistance training for 28 days, with NO-Shotgun® and NO-Synthesize® ingested before and after exercise, respectively, significantly improved body composition and increased muscle mass and performance without abnormally impacting any of the clinical chemistry markers.

Identification of the Eph receptor pathway as a novel target for eicosapentaenoic acid (EPA) modification of gene expression in human colon adenocarcinoma cells (HT-29)

July 2010


119 Reads

The health benefits of polyunsaturated fatty acids (PUFAs), particularly those of the n-3 series are well documented. The mechanisms by which these effects are mediated are not fully clarified. We used microarrays to assess the effects on gene expression in HT29 colon adenocarcinoma cells of exposure to the n-3 fatty acid eicosapentaenoic acid (EPA). HT29 cells were cultured with EPA (150 muM) for up to 24 hr prior to harvesting and isolation of RNA. Microarray results were analyzed within the statistical package 'R', and GeneGo MetaCore was used to identify key pathways of altered gene expression. EphB4, Vav2 and EphA1 gene expression were identified as significantly altered by EPA treatment. Statistically significant changes in gene expression after HT29 exposure to EPA were confirmed in a second experiment by real-time RT-PCR (TaqMan), This experiment also compared the effects of exposure to EPA to arachadonic acid (AA, n-6). Corresponding changes in protein expression were also assessed by Western blotting. Eph receptor mediated signaling is an entirely novel signaling pathway through which EPA may promote a wide range of health benefits, in particular in relation to reduction of colorectal cancer progression.

Table 1 : Using 2 H 2 O to study the effects of feeding and exercise on muscle protein synthesis
Fundamental principal of the precursor:product labeling method to determine muscle protein synthesis. Traditionally, a labeled (tracer) and unlabeled (tracee) amino acid are provided either as a primed-continuous infusion or flooding dose, and mix with the protein-free amino acid pool in the blood. If the fate of the amino acid is incorporation into muscle protein, then entry into the cell is facilitated by amino acid transporters prior to charging an aminoacyl-tRNA. When using 2H2O, the 2H rapidly equilibrates with body water and labels amino acids (e.g., alanine) intracellularly via transamination reactions (e.g., alanine aminotransferase), which can then charge aminoacyl-tRNA and become incorporated into growing peptides.
Measurement of 2H-labeling of body water and protein-bound alanine using gas chromatography-mass spectrometry. Panel A shows that 2H-labeling of body water (plasma) is determined by 2H exchange with carbon-bound hydrogens of acetone. Acetone has a mass-to-charge ratio (m/z) of 58, thus m/z 59 represents 2H-labeling. Panel B shows the methyl-8 derivative upon reacting the protein hydrolysate with N, N-dimethylformamide dimethyl acetal. Three ions that have been characterized are m/z 99 (the base peak that includes α and β-hydrogens of alanine), m/z 143 (includes only the α-hydrogen of alanine) and m/z 158 (represents the molecular ion). Since the precursor (water) labeling is relatively low (e.g., 0.5 to 2%) one typically only measures changes in M+1/M0 ratio, although in theory M+2, M+3, etc. mass isotopomers are generated, their abundance is typically not measurable (e.g., when the water labeling is 0.5%, the abundance of M+6 acetone is ~0.0056, likewise the abundance of M+4 alanine is ~0.0053.7).
Theoretical prediction model based on fractional synthetic rate (FSR) measurements made over 24 h. The fraction of new alanine (f) synthesized in mixed muscle of fish (epaxial myomere), rats (mixed gastrocnemius) and humans (vastus lateralis), and a hypothetical protein that has a rapid renewal rate (protein "x"). As a result of skeletal muscle having a slow renewal rate, calculating a FSR with the traditional precursor:product labeling equation provides a reliable estimate (i.e., there is no significant difference in the values when using rise-to-plateau kinetics, Ft). However, when proteins have a rapid renewal rate (e.g., protein "x"), the affect of long sampling intervals begins to have substantial effects on estimates of FSR. Thus, it is recommended that the labeling protocol be either reduced or multiple samples be collected with calculations made using Ft = fmax × (1-e-kt).
The application of 2H2O to measure skeletal muscle protein synthesis

April 2010


961 Reads

Skeletal muscle protein synthesis has generally been determined by the precursor:product labeling approach using labeled amino acids (e.g., [13C]leucine or [13C]-, [15N]-, or [2H]phenylalanine) as the tracers. Although reliable for determining rates of protein synthesis, this methodological approach requires experiments to be conducted in a controlled environment, and as a result, has limited our understanding of muscle protein renewal under free-living conditions over extended periods of time (i.e., integrative/cumulative assessments). An alternative tracer, 2H2O, has been successfully used to measure rates of muscle protein synthesis in mice, rats, fish and humans. Moreover, perturbations such as feeding and exercise have been included in these measurements without exclusion of common environmental and biological factors. In this review, we discuss the principle behind using 2H2O to measure muscle protein synthesis and highlight recent investigations that have examined the effects of feeding and exercise. The framework provided in this review should assist muscle biologists in designing experiments that advance our understanding of conditions in which anabolism is altered (e.g., exercise, feeding, growth, debilitating and metabolic pathologies).

Supplementary site interactions are critical for the regulation of microsomal triglyceride transfer protein by microRNA-30c

September 2013


57 Reads

Microsomal triglyceride transfer protein (MTTP) is an essential chaperone that assists in the assembly of apolipoprotein B-containing lipoproteins to transport lipids. We have shown that microRNA (miR)-30c regulates MTTP expression but other members of the same family do not. Further, we showed that interactions between miR-30c seed sequence and the 3 -untranslated region of the MTTP mRNA are critical for this regulation. The same seed sequence is shared by all the members of the miR-30 family. Therefore, it is unclear why only miR-30c regulates MTTP expression. Bioinformatics analysis revealed that, miR-30c interacts with MTTP mRNA involving supplementary site, besides seed sequence, forming an intervening loop. Here, we evaluated the importance of the supplementary site and the size of the intervening loop in miR-30c/MTTP mRNA interactions by cloning MTTP 3 -UTR at the end of the luciferase gene and subjecting it to site-directed mutagenesis. Reducing the number of base pairs at the supplementary site abolished the ability of miR-30c to reduce luciferase activity. However, increasing the number of base pairs at the supplementary site, seed sequence or in the intervening loop enhanced the efficacy of miR-30c in reducing luciferase activity. These studies demonstrated that the supplementary site of miR-30c is, but the intervening loop is not, critical for binding to the MTTP mRNA. To our knowledge, this is the first demonstration that miRs might require both seed and supplementary interactions to regulate target mRNA specificity. Further, this study suggests that more potent miR-30c mimics could be synthesized by increasing base pairing in the loop region.

Subchronic exposure to phytoestrogens alone and in combination with diethylstilbestrol - Pituitary tumor induction in Fischer 344 rats

May 2010


94 Reads

Subchronic administration of the potent pharmaceutical estrogen diethylstilbestrol (DES) to female Fischer 344 (F344) rats induces growth of large, hemorrhagic pituitaries that progress to tumors. Phytoestrogens (dietary plant estrogens) are hypothesized to be potential tumor inhibitors in tissues prone to estrogen-induced cancers, and have been suggested as "safer" estrogen replacements. However, it is unknown if they might themselves establish or exacerbate the growth of estrogen-responsive cancers, such as in pituitary. We implanted rats with silastic capsules containing 5 mg of four different phytoestrogens - either coumestrol, daidzein, genistein, or trans-resveratrol, in the presence or absence of DES. We examined pituitary and other organ weights, blood levels of prolactin (PRL) and growth hormone (GH), body weights, and pituitary tissue histology. Blood level measurements of the administered phytoestrogens confirmed successful exposure of the animals to high levels of these compounds. By themselves, no phytoestrogen increased pituitary weights or serum PRL levels after 10 weeks of treatment. DES, genistein, and resveratrol increased GH levels during this time. Phytoestrogens neither changed any wet organ weight (uterus, ovary, cervix, liver, and kidney) after 10 weeks of treatment, nor reversed the adverse effects of DES on pituitaries, GH and PRL levels, or body weight gain after 8 weeks of co-treatment. However, they did reverse the DES-induced weight increase on the ovary and cervix. Morphometric examination of pituitaries revealed that treatment with DES, either alone or in combination with phytoestrogens, caused gross structural changes that included decreases in tissue cell density, increases in vascularity, and multiple hemorrhagic areas. DES, especially in combination with phytoestrogens, caused the development of larger and more heterogeneous nuclear sizes in pituitary. High levels of phytoestrogens by themselves did not cause pituitary precancerous growth or change weights of other estrogen-sensitive organs, though when combined with DES, they counteracted the growth effects of DES on reproductive organs. In the pituitary, phytoestrogens did not reverse the effects of DES, but they did increase the sizes and size heterogeneity of nuclei. Therefore, phytoestrogens may oppose some but not all estrogen-responsive tissue abnormalities caused by DES overstimulation, and appear to exacerbate DES-induced nuclear changes.

Generation of recombinant resistin lentivirus and detection of recombinant gene expression. (A) A full length of mouse resistin coding sequence (0.34 kb) was cloned into a ViraPower-CMV vector (Invitrogen). This recombinant resistin gene construct included a V5 epitope tag and a CMV promoter. (B) A western blot analysis was performed to confirm the expression of the recombinant resistin genes in three different stably transduced cell lines (R18, R20 and R23) using anti-V5 antibodies. The lanes marked by the letter C were loaded with proteins from non-transduced control 3T3-L1 cells. The lane marked by the letter Z was loaded with proteins from cells transduced lentivirus containing recombinant LacZ gene including the V-5 tag and LacZ was detected using anti-V5 antibodies. (C) A western blot analysis was performed to examine the secretion of the recombinant exogenous resistin proteins (R18, R20, and R23) and the endogenous resistin proteins in the medium of 3T3-L1 cells. Exogenous and endogenous resistin proteins were detected using anti-resistin antibodies. The control lane marked by the letter C was loaded with proteins from non-transduced 3T3-L1 cells.
Effects of resistin on gene expression patterns during adipogenesis. Day 0 represents 3T3L1 fibroblasts reaching 100% confluence. Two days after full confluence (Day 2), cells were placed in DMEM containing 25 mM glucose, 0.5 mM isobutylmethylxanthine (IBMX), 1 μm dexamethasone (Dex), 10 μg/ml insulin, and 10% FBS for 3 days; then, on day 5 cells were placed in DMEM containing 25 mM glucose, 10 μg/ml insulin, and 10% FBS for 2 days. After day 7, cells were maintained in DMEM, 25 mM glucose, and 10% FBS. At the indicated time points, resistin and LacZ transduced preadipocytes and adipocytes were lysed and the mRNA levels encoding PPARγ, C/EBPα, and ALBP/aP2 were quantified by quantitative PCR. Results represent the mean ± SE from three separate experiments. Asterisk, P < 0.05; double asterisk, P < 0.01 for resistin versus control cells.
Effects of resistin on GLUT4 activity and expression. Adipocytes transduced with the LacZ gene (Control) or with the resistin gene were incubated for 12 days until fully-differentiated. (A) Resistin overexpressing adipocytes show an inhibition of insulin-stimulated glucose transport activity. Control cells (Bars 1 and 2) and cells over-expressing resistin (Bars 3 and 4), were incubated in the absence (Bars 1 and 3) or presence (Bars 2 and 4) of 100 nM insulin for 30 min at 37°C to induce maximal rates of glucose uptake. Double asterisk, P < 0.01 for (Resistin + Insulin) versus (Control + Insulin). (B) Conditioned medium from resistin transduced adipocytes inhibits the activity of insulin-stimulated glucose transport. 3T3-L1 adipocytes treated with conditioned control medium from LacZ transduced cells (control) (Bars 1 and 2) and conditioned medium from resistin transduced cells (Bars 3 and 4), were incubated in the absence (Bars 1 and 3) or presence (Bars 2 and 4) of 100 nM insulin for 30 min at 37°C to induce maximal rates of glucose uptake. Asterisk, P < 0.05 for (Resistin medium + Insulin) versus (Control medium + Insulin). (C) Resistin decreases the gene expression of GLUT4. Expression of glucose transporter GLUT4 gene was examined using a quantitative PCR assay in resistin transduced adipocytes and LacZ transduced adipocytes during their differentiation process as described in the Fig. 2. Results represent the mean ± SE from three separate experiments. Double asterisk, P < 0.01 for resistin versus control at Day 9.
Effects of resistin overexpression in adipocytes on proinflammatory and anti-inflammatory cytokines. Western blot analyses were performed to examine the levels of three proinflammatory cytokines, IL-6, TNFα, and MCP-1, and one anti-inflammatory cytokine IL-10 in resistin transduced 3T3-L1 cell lines (R18, R20 and R23) and in the LacZ transduced control cells (C) which had been fully differentiated into adipocytes (Day 12).
Proinflammatory cytokine production and insulin sensitivity regulated by overexpression of resistin in 3T3-L1 adipocytes

February 2006


133 Reads

Resistin is secreted from adipocytes, and high circulating levels have been associated with obesity and insulin resistance. To investigate whether resistin could exert autocrine effects in adipocytes, we expressed resistin gene in 3T3-L1 fibroblasts using a lentiviral vector, and selected several stably-transduced cell lines under blasticidin selection. We observed that 3T3-L1 adipocytes expressing resistin have a decreased gene expression for related transcriptional factors (CCAAT/enhancer binding protein α(C/EBPα) , peroxisome proliferator-activated receptor gamma (PPARγ), and adipocyte lipid binding protein (ALBP/aP2) which is one of target genes for the PPARγ during adipocyte differentiation,. Overexpression of resistin increased the levels of three proinflammatory cytokines, tumor necrosis factor alpha (TNFα), interleukin 6 (IL-6) and monocyte chemoattractant protein-1 (MCP-1), which play important roles for insulin resistance, glucose and lipid metabolisms during adipogenesis. Furthermore, overexpressing resistin in adipocytes inhibits glucose transport 4 (GLUT4) activity and its gene expression, reducing insulin's ability for glucose uptake by 30 %. In conclusion, resistin overexpression in stably transduced 3T3-L1 cells resulted in: 1) Attenuation of programmed gene expression responsible for adipogenesis; 2) Increase in expression of proinflammatory cytokines; 3) Decrease in insulin responsiveness of the glucose transport system. These data suggest a new role for resistin as an autocrine/paracrine factor affecting inflammation and insulin sensitivity in adipose tissue.

Table 1 Primer Sequences for quantitative PCR
Bilberry extracts inhibited 3T3-L1 adipocyte differentiation. (A) 3T3-L1 preadipocytes were induced to differentiate in the presence of DMSO or 10, 50 or 100 μg/mL of bilberry extracts for six days. On day 7, the cells were stained with Oil Red O and photographed. The lipid content in these cells was quantitatively determined as described in the Methods and Procedures. Data are expressed as the ratio of samples/control (DMSO treated cells) levels (n = 3). The results are shown as the mean ± S.D. (* p < 0.05, ** p < 0.001, Welch's t-test). (B) 3T3-L1 preadipocytes were induced to differentiate in the presence of DMSO or 100 μg/mL of bilberry extracts. The Ppar γ and adiponectin mRNA levels on day 7 of differentiation were determined by the real-time RT-PCR (n = 3). β -actin was used as the reference gene (** p < 0.001, Welch's t-test).
Effects of bilberry extracts on the expression of adipogenesis-related transcription factors. 3T3-L1 preadipocytes were incubated with DMSO or 100 μg/mL of bilberry extracts and induced to differentiate. The expression levels of (A) master regulators of adipocyte differentiation; Ppar γ , C/ebp α , (B) upstream genes; C/ebp β , C/ebp δ , Klf5 and Srebp1c at various time points after induction were measured by real-time RT-PCR (n = 3). The results are expressed as the fold increase relative to the controls after normalizing to the β -actin expression levels. The results are shown as the mean ± S.D. (* p < 0.05, ** p < 0.001, Welch's t-test).
Anthocyanidins contained bilberry extracts that inhibited 3T3-L1 adipocyte differentiation. (A) Chemical structures of the five major anthocyanidins: pelargonidin, cyanidin, delphinidin, peonidin, and malvidin. (B) 3T3-L1 preadipocytes were induced to differentiate in the presence of DMSO, 100 μg/mL of bilberry or 100 nM of the five anthocyanidins. On day 7, the cells were stained with Oil Red O and the lipid content in these cells was quantitatively determined (n = 3). Results are shown as the mean ± S.D. of the ratio of samples/control (* p < 0.05, ** p < 0.001, Welch's t-test). (C) 3T3-L1 preadipocytes were induced to differentiate in the presence of DMSO or 100 nM of delphinidin. The Srebp1c (day 2) and Ppar γ (day 7) mRNA levels were determined by the real-time RT-PCR (n = 3). β -actin was used as the reference gene (** p < 0.01, Welch's t-test).
Bilberry and anthocyanidins inhibit the insulin signaling pathway. (A) 3T3-L1 preadipocytes were treated with DMSO, bilberry extracts (100 μg/mL) or delphynidin (100 nM), and then stimulated with or without insulin (100 nM) for 5 min. Protein levels of IRS1 and pIRS1 were analyzed by western blot analysis. Band densities were quantified using Image Gauge 4.22 image analysis software. Protein levels are expressed as fraction of control (DMSO treated and without insulin stimulation cells) level. (B) Top significant pathways of the genes commonly altered in the "Bilberry", "Delphinidin" and "Cyanidin" by GSEA (Fisher's exact test). (C) The hypothetical scheme of a mechanism that anthocyanidins-enriched bilberry extracts inhibit adipocyte differentiation via insulin signal.
Anthocyanidins-enriched bilberry extracts inhibit 3T3-L1 adipocyte differentiation via the insulin pathway

March 2011


309 Reads

Obesity and metabolic syndrome are important public concerns, and there is increasing demand for effective therapeutic strategies. Flavonoids are expected to improve the risk factors associated with metabolic syndrome. Anthocyanidins are a kind of flavonoids; well known for their anti-oxidative, anti-inflammatory and anti-tumor properties. However, their effects on adipocytes and molecular systems are not well defined. In this study, we examined the effects of anthocyanidins-enriched bilberry extracts on adipocyte differentiation. Utilizing 3T3-L1 cell line, we investigated that bilberry extracts and anthocyanidins induced inhibition of lipid accumulation during adipogenesis. To identify what is the most important bilberry mediated-effect, we analyzed the expressions of key transcriptional factors associated with adipocyte differentiation by Real Time (RT)-PCR. From the results of RT-PCR, we hypothesized that bilberry extracts and anthocyanidins blocks insulin signal, we determined the phosphorylation of tyrosine residues of insulin receptor substrate 1 (IRS1) protein by western blotting analysis. In addition, we compared the whole-genome expression profiles of early stage of adipocyte differentiation under four different growth conditions (DMSO, bilberry, two anthocyanidins) by microarray analyses and Gene Set Enrichment Analysis (GSEA). Exposure to bilberry extracts and anthocyanidins during adipocyte differentiation inhibited 3T3-L1 differentiation. During this period, bilberry extracts and anthocyanidin significantly decreased a key adipocyte differentiation-associated marker, peroxisome proliferator-activated receptor- γ (Ppar γ ) and sterol regulatory element-binding protein 1c (Srebp1c). Western blotting analysis showed that bilberry extracts and anthocyanidin decreased the phosphorylation of tyrosine residues of IRS1. In addition, microarray experiments and GSEA data revealed significantly altered expression of the known genes of the insulin pathway in cells treated with bilberry extracts or anthocyanidins in the early differentiation stages. Our data demonstrate that anthocyanidin enriched bilberry extracts strongly inhibit the adipocyte differentiation via the insulin pathway. Furthermore, bilberry extracts might be used as a potential complementary treatment for the obese patients with metabolic syndrome.

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