Physiological and behavioral effects of the mycotoxin deoxynivalenol in Tenebrio molitor larvae

Deoxynivalenol (DON) is one of the most prevalent type B trichothecene mycotoxins present in cereals such as: wheat, rye, barley, oats and corn. It initiates a wide range of toxic effects on human and animal health. As an edible insect species for the growing human population, Tenebrio molitor is typically fed on cereal bran or flour. In the present study T. molitor L. larvae were grown for two weeks on wheat bran artificially contaminated with DON at four concentrations: 4.9 μg/g, 8 μg/g, 16 μg/g and 25 μg/g. The effects of DON intake on survival, growth, activity of the antioxidant enzymes - superoxide dismutase (SOD) and catalase (CAT) and the phase II biotransformation enzyme - glutathione-S-transferase (GST), protein content and locomotor activity were monitored in two-month-old T. molitor larvae. The study revealed that DON at concentrations ranging from 4.9 to 25 μg/g wheat bran reduced larval body weight and protein content. Furthermore, it increased SOD and GST activity, had no effect on CAT activity. Also, this study showed that presence of DON in these concentrations has no direct detrimental effects on larval survival, but reduced locomotor activity. The observed effects were particularly pronounced in the larvae given the highest DON concentration 25 μg/g. These finding reveals that DON in artificially contaminated wheat bran at concentrations up to 25 μg/g is able to induce dose-dependent physiological and behavioral changes in T. molitor larvae.     

Dietary D-psicose reduced visceral fat mass in high-fat diet-induced obese rats

D-Psicose, a C-3 epimer of D-fructose, has shown promise in reducing body fat accumulation in normal rats and plasma glucose level in genetic diabetic mice. Effects of D-psicose on diet-induced obesity are not clearly elucidated, and we investigated food intake, body weight, and fat accumulation in rats fed high-fat (HF) diet. Sprague-Dawley rats became obese by feeding HF diet for 4 wk, and were assigned either to normal or HF diet supplemented with or without D-psicose, sucrose, or erythritol for 8 wk. Changing HF to normal diet gained less body weight and adipose tissue due to different energy intake. D-psicose-fed rats exhibited lower weight gain, food efficiency ratio, and fat accumulation than erythritol- and sucrose-fed rats. This effect was more prominent in D-psicose-fed rats with normal diet than with HF diet, suggesting combination of psicose and calorie restriction further reduced obesity. There was no difference in serum cholesterol/high-density lipoprotein (HDL)-C and low-density lipoprotein (LDL)-C/HDL-C ratios between D-psicose group and other groups. Liver weight in 5% psicose group with normal diet was higher than in other groups, but histopathological examination did not reveal any psicose-related change. D-Psicose inhibited the differentiation of mesenchymal stem cell (MSC) to adipose tissue in a concentration-dependent manner. These results demonstrate that D-psicose produces a marked decrease, greater than erythritol, in weight gain and visceral fat in an established obesity model by inhibiting MSC differentiation to adipocyte. Thus, D-psicose can be useful in preventing and reducing obesity as a sugar substitute and food ingredient. PRACTICAL APPLICATION: We can develop D-psicose as a sugar substitute and food ingredient since it can prevent obesity in normal people, but also suppress adiposity as a sugar substitute or food ingredients with antiobesity effect in obese people. D-psicose can be unique functional sweetener because of its function of reducing visceral fat mass and weight gain.     

Individual and combined effects of subclinical doses of deoxynivalenol and fumonisins in piglets

Scope: Deoxynivalenol (DON) and fumonisins (FB) are the most frequently encountered mycotoxins produced by Fusarium species and most commonly co‐occur in animal diets. These mycotoxins were studied for their toxicity in piglets on several parameters including plasma biochemistry, organ histopathology and immune response. Methods and results: Twenty‐four 5‐wk‐old animals were randomly assigned to four different groups, receiving separate diets for 5 wk, a control diet, a diet contaminated with either DON (3 mg/kg) or FB (6 mg/kg) or both toxins. At days 4 and 16 of the trial, the animals were subcutaneously immunized with ovalbumin to assess their specific immune response. The different diets did not affect animal performance and had minimal effect on hematological and biochemical blood parameters. By contrast, DON and FB induced histopathological lesions in the liver, the lungs and the kidneys of exposed animals. The liver was significantly more affected when the two mycotoxins were present simultaneously. The contaminated diets also altered the specific immune response upon vaccination as measured by reduced anti‐ovalbumin IgG level in the plasma and reduced lymphocyte proliferation upon antigenic stimulation. Because cytokines play a key role in immunity, the expression levels of IL‐8, IL‐1β, IL‐6 and macrophage inflammatory protein‐1β were measured by RT‐PCR at the end of the experiment. The expression of these four cytokines was significantly decreased in the spleen of piglets exposed to multi‐contaminated diet. Conclusion: Taken together, our data indicate that ingestion of multi‐contaminated diet induces greater histopathological lesions and higher immune suppression than ingestion of mono‐contaminated diets.     

Effects of Fusarium toxin-contaminated wheat and feed intake level on the biotransformation and carry-over of deoxynivalenol in dairy cows

An experiment was carried out to examine the effects of feeding Fusarium toxin-contaminated wheat (8.21 mg deoxynivalenol (DON) and 0.09 mg zearalenone (ZON) per kg dry matter) at different feed intake levels on the biotransformation and carry-over of DON in dairy cows. For this purpose, 14 ruminal and duodenal fistulated dairy cows were fed a diet containing 60% concentrate with a wheat portion of 55% (Fusarium toxin-contaminated wheat (mycotoxin period) or control wheat (control period)) and the ration was completed with maize- and grass silage (50 : 50) on a dry matter basis. Daily DON intakes ranged from 16.6 to 75.6 mg in the mycotoxin period at dry matter intakes of 5.6-20.5 kg. DON was almost completely biotransformed to de-epoxy DON (94-99%) independent of the DON/feed intake, and the flow of DON and de-epoxy DON at the duodenum related to DON intake ranged from 12 to 77% when the Fusarium toxin-contaminated wheat was fed. In the serum samples, de-epoxy DON was detected in the range of 4-28 ng ml^-1 in the mycotoxin period, while concentrations of DON were all below the detection limit. The daily excretion of DON and de-epoxy DON in the milk of cows fed the contaminated wheat varied between 1 and 10 µg and between 14 and 104 µg, respectively. The total carry-over rates as the ratio between the daily excretion of DON and de-epoxy DON into milk and DON intake were in the ranges of 0.0001-0.0002 and 0.0004-0.0024, respectively. Total carry-over rates of DON as DON and de-epoxy DON into the milk increased significantly with increasing milk yield. In the urine samples, de-epoxy DON was the predominant substance as compared with DON with a portion of the total DON plus de-epoxy DON concentration to 96% when the Fusarium toxin-contaminated wheat was fed, whereas the total residues of DON plus de-epoxy DON in faeces ranged between 2 and 18% of DON intake in the mycotoxin period. The degree of glucuronidation of de-epoxy DON was found to be approximately 100% in serum. From 33 to 80% of DON and from 73 to 92% of de-epoxy DON, and from 21 to 92% of DON and from 86 to 100% of de-epoxy DON were glucuronidated in the milk and urine, respectively. It is concluded that DON is very rapidly biotransformed to de-epoxy DON in the rumen and only negligible amounts of DON and de-epoxy DON were transmitted into the milk within the range of 5.6-20.5 kg day^-1 dry matter intake and milk yields (fat corrected milk) between 10 and 42 kg day^-1.     

Long-term high animal protein diet reduces body weight gain and insulin secretion in diet-induced obese rats

BACKGROUND: The effects of a high protein diet on insulin secretion and glucose metabolism have been quite controversial. The aim of this study was to evaluate the effects of long‐term isocaloric high animal protein intake on insulin secretion in diet‐induced obese rats. RESULTS: After the experimental period (24 weeks), the high‐fat diet‐induced obese rats that were fed isocaloric high‐protein diets (HP) had lower body weight gain (P < 0.01) and lower visceral fat (P < 0.05) than normal protein (NP) rats. Fasting plasma glucagon‐like peptide‐1 (GLP‐1) was also reduced significantly (P < 0.05), as well as serum insulin levels at 5 min and 10 min by intravenous insulin releasing test. In addition, insulin mRNA and pancreatic duodenal homeodomain‐1 (PDX‐1), GLP‐1 protein expression were both markedly lower in HP rats (P < 0.05), while PDX‐1 mRNA in HP rats had no difference from NP rats. CONCLUSION: These results suggest that long‐term isocaloric high animal protein intake reduces the acute insulin response in obese rats and the decrease of insulin is associated with both reduced weight gain and inhibition of PDX‐1 expression. GLP‐1 might be a negative feedback for the balance of energy metabolism secondary to changes of body weight and visceral fat. Copyright © 2012 Society of Chemical Industry     

Annual variation of deoxynivalenol in Danish wheat flour 1998-2003 and estimated daily intake by the Danish population

The occurrence of deoxynivalenol (DON) in Danish wheat flour was studied during the period 1998-2003 by either capillary gas chromatography with electron capture detection and liquid chromatography coupled to an ion trap mass spectrophotometer. A total of 151 samples were collected from mills and the retail market in Denmark. Contamination levels varied considerably from year-to-year with the highest concentrations occurring in samples from the 2002 harvest with mean and median concentrations of 255 and 300 µg kg^-1, respectively. Compared to other harvest years, 2002 had the highest amount of precipitation around flowering time, i.e. from the end of June to the beginning of July covering weeks 25-27. The lowest average levels were found in samples from the 2001 harvest, where weeks 25-27 were dry compared with other harvest years. The highest value (705 µg kg^-1) was obtained in a flour sample from the 2002 harvest, but none of the tested samples exceeded the maximum limit of 750 µg kg^-1, which has been recently introduced by the European Commission for DON in flour used as raw materials in food products. Calculation of chronic or usual intake by a deterministic approach showed that intake did not exceed the TDI of 1 µg kg^-1 bw day^-1 either for the whole population or for children. A probabilistic approach also showed that intake in general was below the TDI, but intake for children in the 99% percentile amounted to more than 75% of the TDI. The highest intake is calculated to be 2.5 µg kg^-1 bw day^-1.     

Contribution of beef consumption to nutrient intake, diet quality, and food patterns in the diets of the US population

This study examined the association between the nutrient contribution of beef, in its lowest and highest fat forms, and diet quality and food patterns in individuals 4+ years of age. Beef consumers were categorized into three groups (lowest lean/highest fat [LLHF]; middle lean/middle fat content; and highest lean/lowest fat [HLLF]) based on the lean and fat content of beef consumed. Compared to non-beef consumers, HLLF consumers had higher intakes of vitamins B₆ and B₁₂, iron, zinc, and potassium. Non-beef consumers had higher intakes of thiamin, folate, calcium, and magnesium than HLLF beef consumers. The HLLF group had significantly higher intakes of vitamins A, C, B₆, and B₁₂; niacin; phosphorus; magnesium; iron; zinc; and potassium, protein and lower intakes of total energy; total fat; SFA; MUFA; total carbohydrates. There was no difference in diet quality between HLLF beef consumers and non-beef consumers. Moderate consumption of lean beef contributes to intakes of selected nutrients and diet quality was similar to non-beef consumers.     

Comparison of the anti‐obesity and hypocholesterolaemic effects of single Lactobacillus casei strain Shirota and probiotic cocktail

This study compared the efficacy of Lactobacillus casei strain Shirota (LAB13) and a probiotic cocktail for their anti‐obesity and other lipid profile modulating effects. Diet‐induced obese rats were supplemented with two different probiotics which are LAB13 (1 × 10⁹ CFU day^?1 per rat) and cocktail of five bacterial strains (1 × 10⁹ CFU day^?1 per rat) for 12 weeks. Comparative data on weight gain, energy intake, liver weight, subcutaneous fat, total fat weights, total cholesterol and leptin levels in both treatment groups showed significant reduction in probiotic‐treated groups compared to the obese control group. Both probiotics have the anti‐obesity and hypocholesterolaemic effects and are able to reduce body weight and fats via reduction in energy intake. Only LAB13 was able to reduce the level of triglyceride significantly. Therefore, the LAB13 is equally effective compared to the probiotic cocktail in weight reduction. LAB13 is more effective in improving lipid profile which is a common medical complication of obesity.     

On the effects of graded levels of Fusarium toxin contaminated wheat in diets for gilts on feed intake, growth performance and metabolism of deoxynivalenol and zearalenone

A total of 36 gilts (103 +/- 6 kg) were divided into four groups and fed diets with increasing proportions of a Fusarium toxin contaminated wheat over a period of 35 days. The concentrations of the indicator toxins deoxynivalenol (DON) and zearalenone (ZON) which were analyzed by HPLC methods were 210 and 4, 3070 and 88, 6100 and 235 and 9570 and 358 mug.kg(-1) diet fed to groups 1-4 respectively. Feed was partially refused during the first 21 days of the experiment by groups 2, 3 and 4 where two, three and six out of nine gilts were affected. No signs of hyperestrogenism or uterotrophic effects were observed due to dietary treatments. Blood serum, urine, bile and liver were analyzed for residues of DON, ZON and their metabolites. DON and its de-epoxidized metabolite (de-epoxy-DON) were detected in all analyzed specimens and increased in a significantly linearly related fashion. Alpha-zearalenol (alpha-ZOL) and beta-ZOL could be detected besides the parent toxin ZON, but only in bile and urine. In conclusion, the impact of dietary treatments on the performance parameters was most pronounced in the highest exposed group. The maximum ratio between DON concentration in liver and diet was 0.0013, and suggests that a possible contamination of pig liver with DON is negligible and does not contribute significantly to human DON exposure.     

上海市居民膳食中铅镉暴露水平评估

目的 了解上海市居民膳食中铅、镉暴露的基础数据,评估上海市市售食品中铅、镉污染的危险性.方法 对上海市市售食品中铅、镉含量进行监测,并结合上海市居民膳食营养素摄入量调查,应用WHO推荐的食品中化学污染物膳食暴露评估方法,对上海市居民膳食中铅、镉暴露水平进行评估.结果 上海市居民平均每周膳食中铅、镉暴露量分别为0.006...     

The effects of supplementation with conjugated linoleic acid on anthropometric indices and body composition in overweight and obese subjects: A systematic review and meta-analysis

Abstract

Clinical trials have indicated conflicting results on the effects of conjugated linoleic acid (CLA) on obesity. The present study aimed to systematically review controlled clinical trials examining the effects of CLA on anthropometric indices and body composition in overweight and obese subjects. Pubmed, Scopus, Web of science, and Cochrane databases were searched between 2000 and December 2017 with no language restriction. Placebo-controlled clinical trials that reported anthropometric indices and body composition in overweight and obese subjects were included. Random-effect model was used to pool the effect estimates. Of 4032 publications, 13 trials were included for the meta-analysis. Pooled effect sizes indicated that CLA significantly reduced body weight (WMD: ?0.52 kg, 95% CI: ?0.83, ?0.21; I²: 48.0%, p?=?0.01), BMI (WMD: ?0.23 kg/m², 95% CI: ?0.39,???0.06; I²: 64.7%, p?=?0.0001), FM (WMD: ?0.61 kg, 95% CI: ?0.98, ?0.24; I²: 53.8%, p?=?0.01) and increased LBM (WMD: 0.19 kg, 95% CI: 0.04, 0.34; I²: 81.4%, p?=?0.0001) compared to the placebo group. However, the effects of CLA on WC (WMD: 0.05 cm, 95% CI: ?0.01, 0.1; I²: 0%, p?=?0.93) was not significant. Additionally, its impact on body weight in subjects older than 44 year (WMD: ?1.05 kg, 95% CI: ?1.75, ?0.35; I²: 57.0%, p?=?0.01), with longer duration (more than 12 weeks) (WMD: ?1.29 kg, 95% CI: ?2.29, ?0.29; I²: 70.3%, p?=?0.003) and dosage more than 3.4 g/day (WMD: ?0.77 kg, 95% CI: ?1.28, ?0.25; I²: 62.7%, p?=?0.004) were greater than comparative groups. Supplementation with CLA can slightly reduce body weight and FM and increase LBM in overweight and obese subjects. However, its efficacy was not clinically considerable. Further studies with high methodological quality are needed to shed light on the effects of CLA on anthropometric indices in overweight and obese subjects.     

Lemon balm extract causes potent antihyperglycemic and antihyperlipidemic effects in insulin‐resistant obese mice

Over the last decades polyetiological metabolic diseases such as obesity and type 2 diabetes have emerged as a global epidemic. Efficient strategies for prevention and treatment include dietary intervention and the development of validated nutraceuticals. Safe extracts of edible plants provide a resource of structurally diverse molecules that can effectively interfere with multifactorial diseases. In this study, we describe the application of ethanolic lemon balm (Melissa officinalis) leaves extract for the treatment of insulin‐resistance and dyslipidemia in mice. We show that lemon balm extract (LBE) activates the peroxisome proliferator‐activated receptors (PPARs), which have key roles in the regulation of whole body glucose and lipid metabolism. Application of LBE (0.6 mg/mL) to human primary adipocytes resulted in specific peroxisome proliferator‐activated receptor target gene expression. LBE treatment of insulin‐resistant high‐fat diet‐fed C57BL/6 mice (200 mg/kg/day) for 6 weeks considerably reduced hyperglycemia and insulin resistance, plasma triacylglycerol, nonesterified fatty acids and LDL/VLDL cholesterol levels. Taken together, ethanolic lemon balm extract can potentially be used to prevent or concomitantly treat type 2 diabetes and associated disorders such as dyslipidemia and hypercholesterolemia.     

Crude and refined millet bran oil alleviate lipid metabolism disorders,oxidative stress and affect the gut microbiota composition in high-fat diet-induced mice

To investigate crude millet bran oil (MBO) and refined millet bran oil (MRO) consumption on lipid metabolism in obese mice, C57BL/6 mice were fed with HFD/MBO and MRO (2 g kg⁻¹ bw per day) for 12 weeks. Both MBO and MRO supplementation effectively alleviated hepatic lipid accumulation, which was associated with downregulation of the expression levels of acetyl-CoA carboxylase (Acaca), fatty acid synthase (Fasn), perilipin-2 (Plin2) and stearoyl-CoA desaturase (Scd). Only MBO supplementation significantly decreased plasma levels of total cholesterol (TC), catalase (CAT), hepatic lipid peroxidation and hepatic oxidative stress. It also increased the abundance of Akkermansia. The refining process caused a reduction of bioactive components (phytosterols, tocopherols and pigments) and a decrease in associated health benefits of MBO. Therefore, MBO can be moderately refined and still retain some health benefits, but new refining methods are needed to enhance the content of active compounds and improve the physiological efficacy of MRO.     

Determination of selenium in selected food samples from Argentina and estimation of their contribution to the Se dietary intake

An optimised FI-HGAAS method was applied to determine the total selenium concentrations in selected high consumption food (fish, beef, chicken, milk, rice, wheat flour, egg) and to estimate their contribution to the Argentinean dietary intake, whose information is scarce nowadays. Through several optimisation steps a suitable method was achieved showing satisfactory figures of merit for all matrices. Average recovery was 96%, RSD < 5%, LODs ranged 2.0–7.0 μg kg⁻¹ and the accuracy was assessed using DOLT-3 NRC certified reference material. Meat and eggs showed the highest values (in μg kg⁻¹, beef: 42–153; chicken: 62–205; fish: 94–314; canned tuna: 272–282; eggs: 134–217), minor values were found for wheat flour (22–42), rice: (<22), pasta (47–64) and milk (<7–9). An estimated intake of 32 and 24 μg day⁻¹ for adult men and women, respectively, suggested a deficient Se intake, leading to further comprehensive surveys of Se occurrence in Argentina.