Differential effects of high-fat-diet rich in lard oil or soybean oil on osteopontin expression and inflammation of adipose tissue in diet-induced obese rats

Purpose

To examine the effect of different dietary fat types on osteopontin (OPN) expressions and inflammation of adipose tissues in diet-induced obese rats.

Methods

Male Sprague–Dawley rats were randomly assigned to one control group fed standard diet (LF, n = 10) and two high-fat diet groups fed isoenergy diet rich in lard or soybean oil (HL or HS, n = 45 each). Diet-induced obese rats in HL and HS group were then subdivided into two groups either continuously fed high-fat diet or switched to low-fat diet for 8 more weeks. Fasting serum glucose, insulin, and OPN concentrations were assayed and QUICKI was calculated; the expression of OPN, IL-6, IL-10, TNF-α, NF-κB, and F4/80 in adipose tissue was determined.

Results

Both high-fat diets lead to comparable development of obesity characterized by insulin resistance and adipose tissue inflammation. Obese rats continuously fed high-fat diet rich in lard oil exhibited the highest fasting serum insulin level and adipose tissue OPN, F4/80, TNF-α, and NF-κB expression level. In both high-fat diet groups, switching to low-fat diet resulted in less intra-abdominal fat mass, decreased expression of F4/80, TNF-α, and NF-κB, while decreased OPN expression was only observed in lard oil fed rats after switching to low-fat diet.

Conclusions

Reducing diet fat or replacing lard oil with soybean oil in high-fat diet alleviates obesity-related inflammation and insulin resistance by attenuating the upregulation of OPN and macrophage infiltration into adipose tissue induced by high-fat diet.     

Water-soluble rice bran enzymatic extract attenuates dyslipidemia, hypertension and insulin resistance in obese Zucker rats

Background and purpose

Rice bran enzymatic extract (RBEE) has advantages compared to the original rice bran or its oils including water solubility, lack of rancidity and increased content in high nutritional proteins and nutraceutical compounds, particularly phytosterols, γ-oryzanol and tocols. Our aim was to determine the beneficial effects of RBEE in the pathogenesis of metabolic syndrome in obese Zucker rats.

Methods

Obese Zucker rats and their lean littermates were fed a 1 and 5 % RBEE-supplemented diet (O1, O5, L1 and L5). Simultaneously, obese and lean Zucker rats, fed a standard diet, were used as controls (OC and LC, respectively). Body weight, food and water intake, and systolic blood pressure were weekly evaluated. After treatment, biochemical assays of serum glucose, insulin, triglycerides (TG), total cholesterol (TC), non-esterified fatty acids (NEFA), adiponectin and nitrates (NO_(x)) were determined.

Results

RBEE treatment reduced circulating levels of TG and TC, whereas increased HDL-cholesterol without altering NEFA values in obese rats. The extract also induced a significant dose-dependent reduction of hypertension linked to obesity. RBEE of 5 % improved insulin resistance and subsequently reduced HOMA-IR index without altering serum glucose levels. Obese animals treated with RBEE showed partial restoration of adiponectin levels and a significant attenuation of pro-inflammatory values of NO_(x).

Conclusion

These findings evidence the nutraceutical properties of RBEE against the pathogenesis of metabolic syndrome by attenuating dyslipidemia, hypertension and insulin resistance as well as by restoring hypoadiponectinemia associated to obesity.     

Anti-anaemia efficacy of β-lactoglobulin hydrolysate-iron complex on iron-deficient anaemic rats

Purpose

The effects of orally administered β-lactoglobulin hydrolysate-iron complex (β-LGH-Fe) on haematological and biochemical parameters in anaemic rats were evaluated. Female weaning Sprague–Dawley rats were fed with iron-deficient diet to induce iron deficiency anaemia. After 6 weeks, the obtained anaemic rats were divided into five groups: iron deficiency control group (iron-deficient diet without β-LGH-Fe complex supplementation, IDC); three groups supplemented with different dosages of β-LGH-Fe complex (0.5 mg Fe/kg BW, iron-deficient diet with low β-LGH-Fe, IDLFe; 2.0 mg Fe/kg BW, iron-deficient diet with medium β-LGH-Fe, IDMF; 4.0 mg Fe/kg BW, iron-deficient diet with high β-LGH-Fe, IDHFe); and ferrous sulphate-supplemented group at a dosage of 2.0 mg Fe/kg BW.

Results

β-LGH-Fe complex could significantly improve hematocrit and haemoglobin decrease, and normalise the serum iron level, total iron-binding capacity and transferrin saturation of anaemic rats in a dose-dependent manner. Serum ferritin content and hepatic nonheme iron level were also increased. In addition, the antioxidant enzyme activities of superoxidase dismutase, catalase and glutathione peroxidase in both plasma and liver homogenate were improved. The production of malondialdehyde and pro-inflammatory cytokines (TNF-α and IL-6) decreased.

Conclusions

It suggests that β-LGH-Fe complex can ameliorate iron deficiency anaemia, which might make it a potential ingredient with anti-anaemia activity.     

The effect of iron and zinc supplementation and its discontinuation on liver antioxidant status in rats fed deficient diets

Purpose

The aim was to investigate the effect of iron or combined iron/zinc supplementation on rat liver antioxidant status.

Methods

The 6-week male Wistar rats were examined in 3 stages: (1) 4-week adaptation to the diets (C—control AIN-93M diet, D—iron deficient and R—with 50 % reduction in all vitamin and mineral amounts); (2) 4-week supplementation with the same regimen enriched with tenfold more iron or iron/zinc; (3) 2-week post-supplementation period (the same diets as in the stage I).

Results

Combined iron/zinc supplementation similarly to iron supplementation alone significantly (p values ≤ 0.05) increased the iron content in the liver in D and R rats after stages II and III. Moreover, iron/zinc supplementation compared to iron supplementation alone significantly decreased the liver concentration of 8-isoprostane (after stage II in D and after stage III in R rats), protein carbonyl groups (only after stage III in R rats) and 8-hydroxy-2-deoxyguanosine (after stage II in R and after stage III in D and R rats). In rats fed R-type of diets after stage II hepatic superoxide dismutase (SOD) and catalase (CAT) activity, but not glutathione peroxidation activity and total antioxidant capacity, was lower in iron and iron/zinc supplemented than in non-supplemented rats, whereas after stage III in iron/zinc supplemented SOD was lower and CAT activity was higher in comparison with non-supplemented and iron supplemented rats.

Conclusions

The simultaneous iron/zinc supplementation can protect liver against peroxidative damage induced by high doses of iron during and after the intervention in rats fed iron-deficient diet and diet with reduced amounts of vitamins and minerals. The post-intervention observation is relevant because the effect may be delayed and visible only after this period.     

Consumption of a high β-glucan barley flour improves glucose control and fatty liver and increases muscle acylcarnitines in the Zucker diabetic fatty rat

Purpose

The soluble fiber β-glucan, a natural component of barley, has been shown to lower the postprandial glucose response and is thought to improve insulin resistance.

Methods

This study examined the effect of chronic consumption of the high β-glucan barley flour on glucose control, liver lipids and markers of muscle fatty acid oxidation in the Zucker diabetic fatty (ZDF) rat. Two groups of ZDF rats were fed diets containing either 6 % β-glucan in the form of barley flour or cellulose as a control for 6 weeks. A group of Zucker lean rats served as a negative control.

Results

The barley flour group had an increased small intestinal contents viscosity compared to the obese control group. After 6 weeks, the barley flour group had reduced glycated hemoglobin, lower relative kidney weights and a reduced area under the curve during a glucose tolerance test, indicating improved glucose control. Fasting plasma adiponectin levels increased in the barley flour group and were not different than the lean control group. ZDF rats on the barley flour diet had lower relative epididymal fat pad weights than the obese control and a greater food efficiency ratio. The barley flour group also had reduced liver weights and a decreased concentration of liver lipids. The barley flour group had significantly higher concentrations of muscle acylcarnitines, a metabolite generated during fatty acid oxidation.

Conclusion

These results show that chronic consumption of β-glucans can improve glucose control and decrease fatty liver in a model of diabetes with obesity.     

Consumption of wheat bran modified by autoclaving reduces fat mass in hamsters

Purpose

To investigate the effect that wheat bran modified by autoclaving (MWB) had on reducing fat accumulation in hamsters fed a hypercholesterolemia- and obesity-inducing diet.

Methods

Male hamsters (n = 45) were randomized into 3 groups and fed a hypercholesterolemia- and obesity-inducing diet with or without 10 % standard wheat bran or MWB for 28 days. Our outcome measures included body composition measured by DXA, oxygen consumption and plasma lipids and glucose concentrations.

Results

Animals fed the MWB diet had lower % fat mass (49.8 vs. 53.4 %; p = 0.02) and higher % lean body mass (47.2 vs. 44.1 %; p = 0.02) compared with controls despite no differences in food intake or weight gain. Additionally, plasma glucose tended to be lower (6.9 vs. 8.5 mmol/l; p < 0.08) in the MWB animals compared with controls.

Conclusions

Our data suggest that the compositional changes in autoclaved wheat bran, specifically solubility of phenolic antioxidants and fiber, may have contributed to the lower fat accumulation in our animals. Further study is needed to determine whether the exact mechanism involved increased lipolysis and energy utilization from adipose.     

Low iron status as a factor of increased bone resorption and effects of an iron and vitamin D-fortified skimmed milk on bone remodelling in young Spanish women

Purpose

This study aimed to determine whether there is a relationship between iron status and bone metabolism, and to compare the effects of the consumption, as part of the usual diet, of an iron or iron and vitamin D-fortified skimmed milk on bone remodelling in iron-deficient women.

Methods

Young healthy iron-deficient or iron-sufficient women (serum ferritin ≤30 ng/mL or >30 ng/mL, respectively) were recruited. Iron-deficient women were assigned to a nutritional intervention consisting of a randomised, controlled, double-blind, parallel design trial of 16 weeks during winter. They consumed, as part of their usual diet, an iron (Fe group, n = 54) or iron and vitamin D-fortified (Fe+D group, n = 55) flavoured skimmed milk (iron, 15 mg/day; vitamin D₃, 5 μg/day, 200 IU). The iron-sufficient women followed their usual diet without supplementation (R group, n = 56). Dietary intake, body weight, iron biomarkers, 25-hydroxyvitamin D (25OHD), parathyroid hormone (PTH), procollagen-type 1 N-terminal propeptide (P1NP), and aminoterminal telopeptide of collagen I (NTx) were determined.

Results

Negative correlations were found between baseline log-ferritin and log-NTx (p < 0.001), and between transferrin and P1NP (p = 0.002). Serum 25OHD increased (from 62 ± 21 to 71 ± 21 nmol/L, mean ± SD, p < 0.001) while P1NP and NTx decreased in Fe+D during the assay (p = 0.004 and p < 0.001, respectively). NTx was lower in Fe+D compared to Fe at week 8 (p < 0.05) and was higher in Fe and Fe+D compared to R throughout the assay (p < 0.01). PTH did not show changes.

Conclusions

Iron deficiency is related with higher bone resorption in young women. Consumption of a dairy product that supplies 5 μg/day of vitamin D₃ reduces bone turnover and increases circulating 25OHD to nearly reach an optimal vitamin D status, defined as 25OHD over 75 nmol/L.     

Effect of dietary calcium (Ca) on body composition and Ca metabolism during growth in genetically obese (β) male rats

Introduction

Obese β rats may be a suitable model to evaluate the association between calcium intake (CaI) and obesity during growth.

Objective

The present study comparatively evaluated Ca absorption and retention, and changes in body composition in spontaneously genetically obese (β) male rats fed three different dietary Ca levels: high 0.9% (HCa); normal: 0.5% (NCa); low: 0.2% (LCa).

Methods

Pregnant rats were fed isocaloric diets which varied in Ca content only. Male pups continued feeding the same maternal diet until postnatal day 60. The percentage of Apparent Ca absorption (CaA %), Ca balance (CaB), body composition, glucose, triglycerides (TGL), and insulin levels were evaluated.

Results

Food consumption and body weight (BW) were higher in Group LCa than in Groups NCa and HCa (p < 0.01); no differences were observed between the latter two groups. Group LCa presented the highest body fat, liver weight, perigonadal and retroperitoneal fat (p < 0.05); conversely, body ashes and total skeleton bone mineral content were significantly lower compared with animals in both the NCa (p < 0.01) and HCa groups (p < 0.01). CaB (mg/day) reached a plateau at the highest CaI (mg/day) value (r = 0.985, p < 0.001). CaA%, serum glucose, insulin, and TGL levels rose as CaI decreased (p < 0.01).

Conclusions

Although further studies are required, low Ca consumption in this strain of rats could modulate BW inducing changes in several lipid metabolism parameters, which in turn lead to an increase in body fat.     

Increased vitamin D-binding protein and decreased free 25(OH)D in obese women of reproductive age

Purpose

Obese subjects have lower circulating 25-hydroxyvitamin D (25(OH)D) than normal-weight subjects. Knowledge is scarce regarding differences in vitamin D-binding protein (DBP), free 25(OH)D, and intake of vitamin D between normal-weight and obese subjects. The purpose of this study was to examine intake and vitamin D status in obese compared with normal-weight women.

Methods

Between September 2009 and October 2011, 43 obese and 43 normal-weight women, 22–45 years of age, mean BMI of 39.1 ± 4.6 and 21.6 ± 1.8 kg/m², respectively, were recruited in the western Sweden region (latitude 57°N). Blood samples, data regarding diet, and sun exposure were collected.

Results

DBP concentrations were 320 ± 121 and 266 ± 104 μg/mL (P = 0.02) in obese and normal-weight women, respectively. Calculated free 25(OH)D was 13.3 ± 5.5 (obese) and 23.7 ± 10.7 (normal-weight) (P < 0.001). The obese women had a 20.1 nmol/L lower mean 25(HO)D concentration compared to normal-weight women (P < 0.001). 56 % of obese women and 12 % of normal-weight women had 25(OH)D concentrations ≤50 nmol/L. There was no statistically significant difference in total vitamin D intake between the groups. 39 % of the women had a total vitamin D intake <7.5 μg/day, the current national recommendation for vitamin D in Sweden.

Conclusions

Obese women had higher DBP concentrations compared with normal-weight women and lower free 25(OH)D. The obese women were more likely to have 25(OH)D concentrations that could be considered suboptimal. Vitamin D intake was generally low in normal-weight and obese women of childbearing age.     

Dietary fat quality in regular fat diets has minor effects on biomarkers of inflammation in obese Zucker rats

Purpose

Adipose tissue-associated chronic inflammation is involved in the pathogenesis of obesity-related diseases. Dietary fatty acids are known to influence inflammatory processes. The aim of this study was to investigate, whether diets with regular fat contents but variable fat qualities affect adipose tissue-associated inflammation through the fatty acid composition of mesenteric adipose tissue (MAT).

Methods

Obese Zucker rats were fed diets containing 7 % wt:wt rapeseed oil, corn oil, or lard for 10 weeks. Fatty acid composition and endocrine function regarding adipokines and cytokines of MAT, number of total CD3⁺ T cells, and cytokine secretion of mesenteric lymph node (MLN)-derived lymphocytes were determined. Local effects in MAT and MLN were compared to systemic effects assessed in serum and peripheral blood mononuclear cells.

Results

Fatty acid composition of MAT reflected dietary fatty acid intake, without affecting endocrine function. Feeding the lard diet for 10 weeks increased the serum adiponectin and TNF-α secretion of blood lymphocytes, whereas CD3⁺ T cells in blood were decreased. No effects were seen for the secretion of adipokines and cytokines from MAT, the amount of T cells in MLN, and cytokine secretion of MLN lymphocytes.

Conclusions

In conclusion, feeding obese rats a diet with regular fat content but variable fat sources for 10 weeks, changed the fatty acid composition of MAT but not its secretory properties or MLN functions. Although the local immune system was not influenced, lard-feeding induced minor changes in systemic immune function.     

Effect of maternal protein restriction during pregnancy and postweaning high-fat feeding on diet-induced thermogenesis in adult mouse offspring

Purpose

Prenatal undernutrition followed by postweaning feeding of a high-fat diet results in obesity in the adult offspring. In this study, we investigated whether diet-induced thermogenesis is altered as a result of such nutritional mismatch.

Methods

Female MF-1 mice were fed a normal protein (NP, 18 % casein) or a protein-restricted (PR, 9 % casein) diet throughout pregnancy and lactation. After weaning, male offspring of both groups were fed either a high-fat diet (HF; 45 % kcal fat) or standard chow (C, 7 % kcal fat) to generate the NP/C, NP/HF, PR/C and PR/HF adult offspring groups (n = 7–11 per group).

Results

PR/C and NP/C offspring have similar body weights at 30 weeks of age. Postweaning HF feeding resulted in significantly heavier NP/HF offspring (P < 0.01), but not in PR/HF offspring, compared with their chow-fed counterparts. However, the PR/HF offspring exhibited greater adiposity (P < 0.01) v the NP/HF group. The NP/HF offspring had increased energy expenditure and increased mRNA expression of uncoupling protein-1 and β-3 adrenergic receptor in the interscapular brown adipose tissue (iBAT) compared with the NP/C mice (both at P < 0.01). No such differences in energy expenditure and iBAT gene expression were observed between the PR/HF and PR/C offspring.

Conclusions

These data suggest that a mismatch between maternal diet during pregnancy and lactation, and the postweaning diet of the offspring, can attenuate diet-induced thermogenesis in the iBAT, resulting in the development of obesity in adulthood.     

Goat milk supplemented with folic acid protects cell biomolecules from oxidative stress-mediated damage after anaemia recovery in comparison with cow milk

Background

Fe overload is a common consequence of the anaemia treatment, increasing the oxidative stress and promoting the accumulation of damaged biomolecules, with the subsequently impairment of cell functions. Oxidative stress and the role of folic acid preventing free radical damage have been extensively studied; nevertheless, no studies are available about the influence of folic acid-supplemented goat milk consumption on the oxidative stress-mediated damage.

Aim

The objective of the present study was to assess the influence of folic acid supplementation of goat milk- or cow milk-based diets, after Fe-overload treatment to palliate anaemia, on oxidative stress-mediated biomolecular damage in the liver, brain, erythrocytes, duodenal mucosa and plasma.

Methods

Control and anaemic rats were fed goat milk- or cow milk-based diets, either with normal Fe or Fe overload (450 mg/kg), and normal folic acid (2 mg/kg) or folic acid supplemented (40 mg/kg) for 30 days.

Results

During chronic Fe repletion, background DNA damage was significantly lower in anaemic rats fed folic acid-supplemented goat milk-based diet, as revealed by tail DNA (%), and folic acid-supplemented goat milk also had a beneficial effect, reducing the extent of lipid peroxidation in liver, plasma, erythrocytes and especially in brain and duodenal mucosa. Furthermore, protein oxidative damage was lower in anaemic rat duodenal mucosa for all goat milk-based diets.

Conclusions

Folic acid supplement in goat milk avoids the undesirable effects of Fe overload during anaemia recovery in all the tissues studied, especially in the liver and duodenal mucosa, which are the tissues with higher exposition to dietary Fe.     

Promotive effects of resistant maltodextrin on apparent absorption of calcium, magnesium, iron and zinc in rats

Background

It has been reported that low-viscous and fermentable dietary fiber and nondigestible oligosaccharides enhance mineral absorption. Resistant maltodextrin, nonviscous, fermentable and soluble source of dietary fiber, has several physiological functions. However, influence of resistant maltodextrin on mineral absorption is unclear.

Aim of the study

We conducted balance studies in rats to investigate effects of resistant maltodextrin and hydrogenated resistant maltodextrin on apparent mineral absorption.

Methods

In experiment 1 (Exp. 1), 40 rats were fed test diets based on AIN-93G with or without resistant maltodextrin or hydrogenated resistant maltodextrin for 2 weeks. In experiment 2 (Exp. 2), 32 rats were cecectomized (CX) or sham-operated (Sham) and fed diets with or without hydrogenated resistant maltodextrin for 1 week.

Results

In Exp. 1, ingestion of resistant maltodextrin and hydrogenated resistant maltodextrin dose-dependently enhanced apparent absorption rates of Ca, Mg, Fe and Zn, and increased cecal fermentation with cecal expansion. In Exp. 2, the absorption rates of Ca and Mg were significantly enhanced by ingestion of hydrogenated resistant maltodextrin in Sham group but not in CX group. The promotion of Fe and Zn absorption was not affected by cecectomy.

Conclusion

Ingestion of resistant maltodextrin and hydrogenated resistant maltodextrin increased apparent Ca and Mg absorptions dependent on cecal fermentation, while other mechanisms may also be involved in promotion of apparent Fe and Zn absorption by resistant maltodextrin.     

Six-transmembrane epithelial antigen of prostate 4 and neutrophil gelatinase-associated lipocalin expression in visceral adipose tissue is related to iron status and inflammation in human obesity

Purpose

Six-transmembrane epithelial antigen of prostate (STEAP)-4 and neutrophil gelatinase-associated lipocalin (NGAL) are novel adipokines related to iron homeostasis with potential roles in insulin resistance and inflammation. The aim of the present work was to evaluate the effect of obesity and iron status on gene expression levels of STEAP-4 and NGAL in visceral adipose tissue (VAT) and its implication in inflammation.

Methods

VAT biopsies obtained from 53 subjects were used in the study. Real-time PCR and Western-blot were performed to quantify the levels of STEAP4 and NGAL in VAT as well as the association with other genes implicated in inflammatory pathways. Circulating ferritin and free iron concentrations were also determined.

Results

Obese patients exhibited significantly increased STEAP4 and NGAL mRNA expression levels (P < 0.001) compared to lean subjects. Protein expression levels of NGAL (P < 0.05) and STEAP4 were also higher in the visceral fat depot of obese patients, although protein levels of STEAP4 did not reach statistical significance. A negative correlation (P < 0.05) between free iron concentrations and gene expression levels of both STEAP4 and NGAL was found, while circulating ferritin concentrations were positively correlated (P < 0.05) with NGAL mRNA after body fat (BF) adjustment. Furthermore, a significant positive association between STEAP4 and NGAL gene expression levels with inflammatory markers was also detected (P < 0.01).

Conclusion

These findings represent the first observation that STEAP4 and NGAL mRNA and protein levels in human VAT are related to iron status. Moreover, STEAP4 and NGAL are associated with pro-inflammatory markers suggesting their potential involvement in the low-grade chronic inflammation accompanying obesity.     

Changes in cardiac energy metabolic pathways in overweighed rats fed a high-fat diet

Background

Heart produces ATP through long-chain fatty acids beta oxidation.

Purpose

To analyze whether in ventricular myocardium, high-fat diet may modify the expression of proteins associated with energy metabolism before myocardial function was affected.

Methods

Wistar Kyoto rats were divided into two groups: (a) rats fed standard diet (control; n = 6) and (b) rats fed high-fat diet (HFD; n = 6). Proteins from left ventricles were analyzed by two-dimensional electrophoresis, mass spectrometry and Western blotting.

Results

Rats fed with HFD showed higher body weight, insulin, glucose, leptin and total cholesterol plasma levels as compared with those fed with standard diet. However, myocardial functional parameters were not different between them. The protein expression of 3-ketoacyl-CoA thiolase, acyl-CoA hydrolase mitochondrial precursor and enoyl-CoA hydratase, three long-chain fatty acid β-oxidation-related enzymes, and carnitine-O-palmitoyltransferase I was significantly higher in left ventricles from HFD rats. Protein expression of triosephosphate isomerase was higher in left ventricles from HFD rats than in those from control. Two α/β-enolase isotypes and glyceraldehyde-3-phosphate isomerase were significantly increased in HFD rats as compared with control. Pyruvate and lactate contents were similar in HFD and control groups. Expression of proteins associated with Krebs cycle and mitochondrial oxidative phosphorylation was higher in HFD rats.

Conclusions

Expression of proteins involved in left ventricle metabolic energy was enhanced before myocardial functionality was affected in rats fed with HFD. These findings may probably indicate higher cardiac energy requirement due to weight increase by HFD.     

Plantago maxima leaves extract inhibits adipogenic action of a high-fat diet in female Wistar rats

Purpose

The primary objective of this study is to investigate the content of biologically active compounds producing an antioxidant effect in Plantago maxima and their influence on main mechanisms of dietary obesity development.

Methods

Biologically active compounds in P. maxima were tested using paper chromatography. In in vivo experiment, high-fat-fed Wistar rats obtained P. maxima water extract for 3 months. Morphometric parameters, weight gain, serum adipokines, and cytokines, as well as oxidative stress biomarkers in rats’ tissues were evaluated. Gut microflora was also examined.

Results

Plantago maxima leaves used in the experiment contained significant amount of flavonoids, iridoids, phenol carboxylic acids, and tannins and ascorbic acid. Our in vivo experiment data demonstrate that P. maxima water extract prevents excessive adiposity in a diet-induced model. P. maxima consumption reduced serum leptin (twofold), macrophage chemoattractant protein-1 (sevenfold), tumor-necrosis factor-α (25 %), and interleukine-6 (26 %) levels. P. maxima water extract decreased adipose tissue oxidative stress biomarkers in rats fed a high-fat diet. In addition, increased bacterial growth in the diet-induced obesity model was reversed by the P. maxima extract treatment.

Conclusion

Plantago maxima water extract possessed antiadipogenic, antidiabetic, antiinflammatory, antioxidant activity, and normalized gut microflora in a rat model of diet-induced excessive adiposity due to a high content of biologically active compounds.     

Low dietary calcium and obesity: a comparative study in genetically obese and normal rats during early growth

Purpose

A low calcium intake (LCaI) may predispose to obesity, and excessive fat mass may be detrimental to bone. The impact of Ca inadequacy would be greater in subjects predisposed to obesity. LCaI effect on obesity development during the rapid growth period was compared in two strains of rats: spontaneously obese IIMb/β (O) and Wistar (W). Pregnant rats were fed 0.5 % (N) or 0.2 % (L) of Ca (OLCa, ONCa, WLCa and WNCa). Male pups were fed the maternal diet until day 60.

Methods

Body composition, lipid profile, glucose homeostasis, 25 hydroxyvitamin D, Ca-phosphorus, and bone metabolism were evaluated.

Results

BW and body fat were higher, whereas body protein was lower in OLCa versus ONCa (p < 0.05). OLCa presented the highest body fat, glucose, non-HDL and total cholesterol, TGL, insulin levels, and HOMA-IR, liver weight, and adipose perigonadal plus retroperitoneal pads (p < 0.05). WLCa did not exhibit an increase BW and only showed a slight change in body composition with minor biochemical alterations compared to WNCa (p < 0.05). Osteocalcin, CTX, and proximal tibia and lumbar spine BMDs were lower in O than in W rats fed the same Ca diet (p < 0.05). Body ash and Ca content, and total skeleton BMC/BW were lower in OLCa and WLCa versus their corresponding NCa groups (p < 0.05).

Conclusion

The negative effect of a low Ca diet on fat mass accumulation and lipid profile may be more evident in rats predisposed to obesity. Nevertheless, low CaI interferes with the normal glucose homeostasis leading to an increase in insulin resistance. Low CaI during early growth may be an obesogenic factor that may persist into adult life and may account for the development of obesity and some of its co-morbidities.     

Cardioprotective and hepatoprotective effects of ellagitannins from European oak bark (Quercus petraea L.) extract in rats

Background

Red wine contains many potentially bioactive polyphenols including resveratrol, catechins, anthocyanins and flavonoids as well as tannins derived from oak during maturation. This study examined the effects of a mixture of ellagitannins from oak bark (Quercus petraea L.) on cardiovascular, metabolic and liver changes in high-carbohydrate, high-fat diet–fed rats and in Spontaneously Hypertensive Rats (SHR).

Methods

First, 8-week-old male Wistar rats were divided into four groups and given either cornstarch diet, cornstarch diet + oak bark extract (0.5 mL/kg food), high-carbohydrate, high-fat diet or high-carbohydrate, high-fat diet + oak bark extract (0.5 mL/kg food) for 16 weeks. Oak bark extract was added to the diets for last 8 weeks of the feeding period. Secondly, SHR aged 42 weeks fed on standard chow diet were divided into two groups with and without oak bark extract treatment for 12 weeks (0.5 mL/kg food).

Results

The high-carbohydrate, high-fat diet induced signs of metabolic syndrome along with cardiovascular remodelling and non-alcoholic steatohepatitis. Oak bark extract attenuated the signs of metabolic syndrome in high-carbohydrate, high-fat diet–fed rats and improved the structure and function of the heart and the liver. SHR after oak bark extract treatment for 12 weeks showed lower systolic blood pressure, lower cardiac fibrosis and cardiac stiffness and improved vascular reactivity.

Conclusions

Oak bark extract containing ellagitannins improved cardiovascular, metabolic and liver parameters in these rat models of human disease, suggesting that part of the benefits attributed to red wine may be produced by these ellagitannins.