Ability of dairy fat in inducing metabolic syndrome in rats

Effects of Microalgae on Metabolic Syndrome

Metabolic syndrome (MetS) is a cluster of metabolic disturbances, including abdominal obesity, hypertension, hypertriglyceridemia, reduced high-density lipoprotein cholesterol (HDL-C) and hyperglycemia. Adopting a healthier lifestyle and multiple drug-based therapies are current ways to manage MetS, but they have limited efficacy, albeit the prevalence of MetS is rising. Microalgae is a part of the human diet and has also been consumed as a health supplement to improve insulin sensitivity, inflammation, and several components of MetS. These therapeutic effects of microalgae are attributed to the bioactive compounds present in them that exhibit antioxidant, anti-inflammatory, anti-obesity, antihypertensive, hepatoprotective and immunomodulatory effects. Therefore, studies investigating the potential of microalgae in alleviating MetS are becoming more popular, but a review on this topic remains scarce. In this review, we discuss the effects of microalgae, specifically on MetS, by reviewing the evidence from scientific literature covering in vitro and in vivo studies. In addition, we also discuss the underlying mechanisms that modulate the effects of microalgae on MetS, and the limitations and future perspectives of developing microalgae as a health supplement for MetS. Microalgae supplementation is becoming a viable approach in alleviating metabolic disturbances and as a unique addition to the management of MetS.

Rodent models of metabolic disorders: considerations for use in studies of neonatal programming

Epidemiologically, metabolic disorders have garnered much attention, perhaps due to the predominance of obesity. The early postnatal life represents a critical period for programming multifactorial metabolic disorders of adult life. Though altricial rodents are prime subjects for investigating neonatal programming, there is still no sufficiently generalised literature on their usage and methodology. This review focuses on establishing five approach-based models of neonatal rodents adopted for studying metabolic phenotypes. Here, some modelled interventions that currently exist to avoid or prevent metabolic disorders are also highlighted. We also bring forth recommendations, guidelines and considerations to aid research on neonatal programming. It is hoped that this provides a background to researchers focused on the aetiology, mechanisms, prevention and treatment of metabolic disorders.

Effects of Resveratrol Against Induced Metabolic Syndrome in Rats: Role of Oxidative Stress, Inflammation, and Insulin Resistance

Metabolic syndrome (MS) is a serious health problem associated with an increase in risk factors for hepatic steatosis, which is the most common liver disease today. The goal of this study was to investigate the protective effects of resveratrol against metabolic alterations associated with a high-fat high-fructose diet (HFFD). Thirty-two male rats were randomly divided into four equal groups: control (cont.), metabolic syndrome (MS), resveratrol (Res), and metabolic syndrome treated with resveratrol (MS + Res). Resveratrol was administrated orally at a dose of 30 mg/kg·bw, daily. After 10 weeks, body weight, serum biochemical parameters, hepatic oxidative stress, inflammatory markers, as well as mRNA levels of hepatic genes related to lipid metabolism and insulin signaling were measured. In addition, the liver was examined histopathologically to detect lipid deposition. Increased body weight, hepatic dysfunction, dyslipidemia, hepatic insulin resistance, hepatic oxidative and inflammatory stress conditions, upregulation of mRNA expression level of sterol regulatory element binding protein 1-c (SREBP1-c), and downregulation of mRNA expression levels of peroxisome proliferated activated receptor alpha (PPARα) and insulin receptor substrate-2 (IR-S2) were all observed in the MS rats. Hepatic steatosis was confirmed by hematoxylin and eosin and Oil Red O staining. Administration of resveratrol reduced liver steatosis, oxidative stress, and inflammatory state. Also, it improved lipid profile as well as insulin sensitivity and reverted alterations in hepatic mRNA expression levels of the tested genes. Based on these findings, resveratrol could be proposed as a therapeutic approach for MS prevention.

Oral contraceptive pill and metabolic syndrome: Fasa Persian Cohort Study (Descriptive study)

BACKGROUND AND AIMS

The contraceptive use is 56% and prevalence of metabolic syndrome (MetS) is 30% in Iran. The aim of this study investigates relationship between oral contraceptive pills (OCP) use and MetS in women in the cohort population of Fasa city.

METHODS

In a cross-sectional study, 5489 women aged 35-70 years were studied for 5 years in the Sheshdeh area in 2016. MetS were calculated using adult treatment panel III (ATP III) and international diabetes federation (IDF) methods. The odds ratio (OR) with a 95% confidence interval (CI) was reported. Linear regression was used to eliminate the confounding effect.

RESULTS

The OR of developing MetS in the OCP recipients was estimated as higher than the non-recipients. The OR of developing MetS using IDF criteria in OCP recipients was (OR = 0.896,95% CI:0.800-1.004). that increased to (OR = 1.230,95% CI:1.084-1.395) after adjusting for confounding variables. Also, the odds ratio using ATP (III) criteria was (OR = 0.900,95% CI:0.804-1.009). that increased to (OR = 1.245,95% CI:1.098-1.413) after adjusting for confounding variables. Also, the OR of developing MetS in OCP recipients decreased with increasing the number of MetS components from 1.199 to 0.812,95% CI:0.771-1.864,0.467-1.413, but after adjustment, increased from 1.151 to 1.747,95% CI:0.733-1.805,0.815-3.746.

CONCLUSION

The results of the present study showed that the OR of developing MetS in OCP recipients using both IDF and ATP (III) methods was higher after adjusting by confounder effects so it is recommended monitoring by physicians.

Functional milk fat enriched in conjugated linoleic acid prevented liver lipid accumulation induced by a high-fat diet in male rats

The aim was to investigate the potential effect of functional milk fat (FMF), naturally enriched in conjugated linoleic acid, on the prevention of liver lipid accumulation and some biochemical mechanisms involved in the liver triacylglycerol (TAG) regulation in high-fat (HF) fed rats. Male Wistar rats were fed (60 days) with S7 (soybean oil, 7%) or HF diets: S30 (soybean oil, 30%), MF30 (soybean oil, 3% + milk fat -MF-, 27%) or FMF30 (soybean oil, 3% + FMF, 27%). Nutritional parameters, hepatic fatty acid (FA) composition, liver and serum TAG levels, hepatic TAG secretion rate (TAG-SR), lipoprotein lipase (LPL) activity in adipose tissue and muscle, activities and/or mRNA levels of lipogenic and β-oxidative enzymes, and mRNA levels of transcription factors and FA transport proteins were assessed. The hepatic lipid accumulation induced by the S30 diet was associated with increased mRNA levels of FA transporters; and it was prevented by FMF through an increase in the hepatic TAG-SR, carnitine palmitoyltransferase-1a activity and peroxisome proliferator-activated receptor alpha mRNA levels, as well as by a reduction of the mRNA levels of FA transporters. The hypotriacylglyceridaemia observed in S30 was related with an increased LPL activity in adipose tissue and it was reverted by FMF through the increased hepatic TAG-SR. In brief, FMF prevented the liver lipid accumulation induced by HF diets by increasing the hepatic TAG-SR and β-oxidation, and reducing the hepatic FA uptake. The increased hepatic TAG-SR induced by FMF could be responsible for the attenuation of serum TAG alterations.

Diagnostic Criteria for Metabolic Syndrome in Diet-Induced Rodent Models: A Systematic Review

BACKGROUND

Thousands of publications in recent years have addressed the induction of metabolic syndrome (MetS) in rodents. However, the criteria and the reference values for diagnosing this disease have not been defined.

OBJECTIVE

Our main objective was to carry out a systematic review to gather evidence about the criteria for biochemical and anthropometric parameters in which scientific studies have relied on to report that rats developed MetS from a previous dietary manipulation.

METHODS

We compiled characteristics and findings of diet-induced MetS with high-fat, high-carbohydrate, high-fat/high-carbohydrates, and cafeteria diet from PubMed and Science Direct databases published in the last 5 years.

RESULTS

The results on the principal determinants for the syndrome, published in the reviewed articles, were chosen to propose reference values in the rat models of food induction.

CONCLUSION

The values obtained will serve as reference cut-of points in the development of the disease; in addition, the compilation of data will be useful in planning and executing research protocols in animal models.

Association between dietary patterns with insulin resistance in an Iranian population

AIM

To assess the association between dietary patterns no single food or group, and risk of insulin resistance (Fasting blood sugar (FBS), Fasting insulin, 2h-glucose, 2h-insulin and HOMA-IR).

METHODS

In a cross-sectional, population-based study in Tehran, Iran, 2016-2017. Adults (n = 1500, 38% men) mean age 43.72 ± 14.9 years. Dietary intake was collected by semi-quantitative food frequency questionnaire and insulin resistance was evaluated by Fasting blood sugar (FBS), Fasting insulin, 2h glucose, 2h insulin and HOMA-IR. Associations were assessed by using correlation and multivariable linear regression.

RESULTS

After controlling of the confounding factor or possible underlying such as gender, age, menopausal, BMI, physical activity and the amount of daily energy intake, unhealthy dietary pattern had a positive relationship with all indexes of insulin resistance except 2h glucose and HOMA-IR, healthy dietary pattern had negative and significant relationship with indexes of insulin resistance but apart from 2h glucose.

CONCLUSIONS

It can be figured out that receiving diet rich in healthy foods might reduce the risk of creating insulin resistance.

Association between dietary patterns with kidney function and serum highly sensitive C-reactive protein in Tehranian elderly: An observational study

BACKGROUND

Accumulating evidence suggests that diet is associated with kidney function. This study was carried out to examine the association between a posteriori dietary patterns and kidney function in older adults.

MATERIALS AND METHODS

In a cross-sectional study, 266 older adults, aged 60-83 years, were included. Anthropometric measures were recorded. Biochemical measurements of blood and urine samples were measured. Information on diet was collected using a validated semi-quantified food frequency questionnaire with 168 food items and factor analysis performed to derive major dietary patterns. Estimated glomerular filtration rate (eGFR) was calculated using the chronic kidney disease (CKD) Epidemiology Collaboration equation.

RESULTS

A total of 266 participants with mean body mass index (BMI) 29.75 ± 4.53 kg/m2 and age, 66.2 ± 5.3 years, were included in the current study. Three major dietary patterns were identified using factor analysis based on intake data (28% of the total variance of food intake in the population). After adjustment for age, sex, BMI, and energy intake, we found a positive significant relationship between the first pattern and eGFR (P = 0.031). A positive significant association between adherence to the traditional dietary pattern and urine creatinine was also observed (P = 0.035). In addition, in logistic regression model and after control for covariates, a positive association was observed between adherence to traditional dietary pattern with odds of eGFR < 60 ml/min/1.73 m2 (P = 0.043) and urinary albumin-to-creatinine ratio ≥ 30 mg/g (P = 0.038).

CONCLUSION

It is concluded that higher adherence to the healthy dietary pattern may improve renal function while Iranian traditional pattern was associated with significantly increased odds of incident CKD and albuminuria.

Dietary pattern in pregnancy and risk of gestational diabetes mellitus (GDM)

AIM

Among the most common metabolic disorders during pregnancy is gestational diabetes mellitus (GDM). This research was conducted to examine the dietary pattern in women with GDM.

MATERIAL AND METHODS

In this case-study, 204 pregnant women (104 cases and 100 control women) were chosen through convenient sampling and random sampling. The subjects' food intakes were assessed using semi-quantitative food frequency questionnaire, while their activities evaluated by physical activity questionnaire. Anthropometric indices were measured based on standard instructions, and the body mass index was calculated. The dietary patterns were determined using principal component analysis and its relationship with preeclampsia was tested using logistic regression method.

RESULTS

Unhealthy and healthy dietary patterns were found among the pregnant women. In the unhealthy group, after modifying the effect of confounding variables, a significant relationship was observed between dietary pattern and having gestational diabetes (OR = 2.838,95% CI:1.039-7.751). In the healthy group, on the other hand, the people in the fourth quartile had 149% and 184% higher chance not to catch gestational diabetes before and after modification with confounders, respectively (OR = 0.284,95% CI:0.096-0.838), when compared with people in the first quartile.

CONCLUSION

The findings indicated that selection of foods including fruits, vegetables, low-fat dairies, etc. as healthy dietary pattern is associated with diminished risk of GDM among pregnant women. Determining healthy dietary pattern during pregnancy, considering the foods consumed among pregnant women, as a useful and practical guide during this period can be publicized for training and nutritional interventions.

Waist circumference is a mediator of dietary pattern in Non-alcoholic fatty liver disease

Non-alcoholic fatty liver disease (NAFLD) is an example of pathological fat accumulation in the liver and one of the major health conditions in the world. This study aimed to examine the independent role of dietary patterns in the development of NAFLD. In a cross-sectional study, 1500 individuals referred to a nutrition clinic were randomly selected, their demographic, anthropometric and blood metabolic indices were obtained, and food frequency questionnaires were completed for them. Liver stiffness was calculated using the NAFLD score formula and fibroscan. The two dominant dietary patterns identified were the “healthy” and “unhealthy dietary patterns”. A significant percentage of those with NAFLD (45%) were in the upper quartile of the unhealthy model; however, only 10% had the healthy pattern (p < 0.001). In this study, 32.9 and 13.9% of the healthy and unhealthy participants were in the upper quartile of the healthy diet pattern. Also, it was shown that waist circumference is a strong mediator of dietary patterns and NAFLD relationship, and the indirect effect of diet through abdominal circumference is 28 times greater than the direct effect on NAFLD. The results suggested that healthy and unhealthy dietary patterns are respectively associated with lower- and higher-risk of NAFLD but the role of waist circumference as a mediator deserves more consideration.

Additional dexamethasone in chemotherapies with carboplatin and paclitaxel could reduce the impaired glycometabolism in rat models

Background

Side-effects have been considered as the limitation of the chemotherapy agents’ administration and life quality in patients with ovarian cancers. In order to explore the influence of the chemotherapy agents commonly used in ovarian cancer patients on the blood glucose metabolism in rat models, we conducted this study which simulated the conditions of clinical protocols.

Methods

Eighty clean-grade female Wistar rats were randomized into 8 groups: Group 1 (Negative control), Group 1′ (Dexamethasone), Group 2 (Carboplatin), Group 2′ (Carboplatin-plus-dexamethasone), Group 3 (Paclitaxel), Group 3′ (Paclitaxel-plus-dexamethasone), Group 4 (Combined therapy), Group 4′ (Combined-therapy-plus-dexamethasone). On day 0, 4, 7 and 14, after fasted for 12 h, the rats in all groups underwent a glucose load and their blood glucose, glucagon and insulin levels were measured.

Results

The glucose levels in group 2, 3 and 4 at 1 h after the loading on day 4 significantly increased (P = 0.190, 0.008 and 0.025, respectively). The glucagon levels in group 3 and 4 showed a similar trend and the increase was not suppressed by the glucose loading (P < 0.001). A significant decrease of insulin levels in group 2, 3 and 4 were observed on day 14 after treatment (P = 0.043, 0.019 and 0.019, respectively). The change of HOMA2 %B, an index reflects the ability of insulin secretion was negatively corresponded to the glucose levels, and the trends of HOMA2 IR, an index shows insulin resistance, were positively correlated to the glucose levels. The application of dexamethasone could reduce the degree of increased glucose levels significantly in group 2, 3 and 4. There were no differences in overall survival between the 8 groups. Edema in the stroma of pancreases was observed in group 3, 3′, 4 and 4′ on day 4 after treatment (P = 0.002, 0.002, 0.000 and 0.000 respectively) and lasted until day 14.

Conclusions

Carboplatin and paclitaxel administration could cause a transient hyperglycemia in rats. This effect might occur by the combination of glucagon accumulation due to the decrease in islet cell secretion. The additional dexamethasone in the combination protocol of carboplatin and paclitaxel seemed to reduce the impaired blood glucose metabolism.

Validation of a One-Step Method for Extracting Fatty Acids from Salmon, Chicken and Beef Samples

Fatty acid extraction methods are time-consuming and expensive because they involve multiple steps and copious amounts of extraction solvents. In an effort to streamline the fatty acid extraction process, this study compared the standard Folch lipid extraction method to a one-step method involving a column that selectively elutes the lipid phase. The methods were tested on raw beef, salmon, and chicken. Compared to the standard Folch method, the one-step extraction process generally yielded statistically insignificant differences in chicken and salmon fatty acid concentrations, percent composition and weight percent. Initial testing showed that beef stearic, oleic and total fatty acid concentrations were significantly lower by 9-11% with the one-step method as compared to the Folch method, but retesting on a different batch of samples showed a significant 4-8% increase in several omega-3 and omega-6 fatty acid concentrations with the one-step method relative to the Folch. Overall, the findings reflect the utility of a one-step extraction method for routine and rapid monitoring of fatty acids in chicken and salmon. Inconsistencies in beef concentrations, although minor (within 11%), may be due to matrix effects.

PRACTICAL APPLICATION

A one-step fatty acid extraction method has broad applications for rapidly and routinely monitoring fatty acids in the food supply and formulating controlled dietary interventions.

Changes in the Diaphragm Lipid Content after Administration of Streptozotocin and High-Fat Diet Regime

The diaphragm is a dome-shaped skeletal muscle indispensable for breathing. Its activity contributes up to 70% of the total ventilatory function at rest. In comparison to other skeletal muscles, it is distinguished by an oxidative phenotype and uninterrupted cyclic contraction pattern. Surprisingly, the research regarding diaphragm diabetic phenotype particularly in the light of lipid-induced insulin resistance is virtually nonexistent. Male Wistar rats were randomly allocated into 3 groups: control, streptozotocin-induced (STZ) type-1 diabetes, and rodents fed with high-fat diet (HFD). Additionally, half of the animals from each group were administered with myriocin, a robust, selective inhibitor of ceramide synthesis and, therefore, a potent agent ameliorating insulin resistance. Diaphragm lipid contents were evaluated using chromatography. Fatty acid transporter expression was determined by Western blot. The STZ and HFD rats had increased concentration of lipids, namely, ceramides (CER) and diacylglycerols (DAG). Interestingly, this coincided with an increased concentration of long-chain (C ≥ 16) saturated fatty acid species present in both the aforementioned lipid fractions. The CER/DAG accumulation was accompanied by an elevated fatty acid transporter expression (FATP-1 in HFD and FATP-4 in STZ). Surprisingly, we observed a significantly decreased triacylglycerol content in the diaphragms of STZ-treated rats.