Synbiotic effects of β-glucans from cauliflower mushroom and <Emphasis Type="Italic">Lactobacillus fermentum</Emphasis> on metabolic changes and gut microbiome in estrogen-deficient rats

Background

We investigated whether the long-term consumption of a symbiotic formulation with Lactobacillus fermentum (probiotic) and β-glucan from cauliflower mushroom (prebiotic) would delay the progression of post-menopausal symptoms in ovariectomized (OVX) rats and explored their mechanisms of action, including changes in gut microbiota.

Methods

OVX rats were fed with high-fat diets containing 1% dextrin (control), 1% lyophilized cauliflower mushroom extract (CFM), 0.1% L. fermentum JS (LFE), 1% CFM plus 0.1% LFE (CFLF), or 30 μg 17β-estradiol/kg body weight (positive-control) for 8 weeks.

Results

CFM contained 95.8% β-glucans. OVX increased the ratio of Firmicutes and Bacteroidetes in the large intestines. Only CFLF lowered tail skin temperature without increasing serum 17β-estradiol and uterine index. Visceral fat mass was lower in CFLF and positive-control groups by increasing daily energy expenditure and fat oxidation. Dyslipidemia induced by OVX was improved by CFM and CFLF as much as in the positive-control group. Homeostasis model assessment estimate of insulin resistance was lower in CFLF than in the positive-control. Hepatic insulin signaling (pAkt?GSK-3β) was potentiated in the ascending order of the control, LFE, CFM, CFLF, and positive-control. AMPK phosphorylation showed similar patterns of hepatic insulin signaling but LFE increased it more than CFM. The changes in gut microbiota were prevented by CFLF in OVX rats, and the ratio of Firmicutes and Bacteroidetes in the CFLF was similar to the positive-control group.

Conclusion

OVX changed gut microbiota and was associated with menopausal symptoms; however, the synbiotics, CFM and LFE, prevented menopausal symptoms and improved the gut microbiota in estrogen-deficient rats.

     

Reproductive Senescence Blunts Response of Estrogen Receptor-α Expression to Estrogen Treatment in Rat Post-Ischemic Cerebral Microvessels

Background

Several studies demonstrate that estrogen treatment improves cerebral blood flow in ischemic brain regions of young ovariectomized (OVX) rats. Estrogen receptor-α (ER-α) may mediate estrogen’s beneficial actions via its effects on the cerebral microvasculature. However, estrogen-derived benefit may be attenuated in aged, reproductively senescent (RS) rats. Our goal was to determine the effects of aging, estrogen deprivation and estrogen repletion with oral conjugated estrogens (CE) on postischemic cerebral microvascular protein expression of ER-α and ER-β.

Methods

Fisher-344 (n = 37) female rats were randomly divided into the following groups: OVX, OVX CE-treated, RS untreated, and RS CE-treated. After 30 days pretreatment with CE (0.01 mg/kg) rats were subjected to15 min. transient global cerebral ischemia. Non-ischemic naïve, OVX and RS rats were used as controls. Expression of ER-α and ER-β in isolated cortical cerebral microvessels (20 to 100 µm in diameter) was assessed using Western blot and immunohistochemistry techniques.

Results

Age and reproductive status blunted nonischemic ER-α expression in microvessels of OVX rats (0.31±0.05) and RS rats (0.33±0.06) compared to naïve rats (0.45±0.02). Postischemic microvascular expression of ER-α in OVX rats (0.01±0.0) was increased by CE treatment (0.04±0.01). Expression of ER-α in microvessels of RS rats (0.03±0.02) was unaffected by CE treatment (0.01±0.02). Western blot data are presented as a ratio of ER-α or ER-β proteins to β-actin and. Oral CE treatment had no effect on ER-β expression in postischemic microvessels of OVX and RS rats. Statistical analysis was performed by One-Way ANOVA and a Newman-Keuls or Student’s post-hoc test.

Conclusion

Chronic treatment with CE increases ER-α but not ER-β expression in cerebral microvessels of OVX rats. Aging appears to reduce the normal ability of estrogen to increase ER-α expression in postischemic cerebral microvessels.     

Distributional Variations in Trabecular Architecture of the Mandibular Bone: An In Vivo Micro-CT Analysis in Rats

Purpose

To evaluate the effect of trabecular thickness and trabecular separation on modulating the trabecular architecture of the mandibular bone in ovariectomized rats.

Materials and Methods

Fourteen 12-week-old adult female Wistar rats were divided into an ovariectomy group (OVX) and a sham-ovariectomy group (sham). Five months after the surgery, the mandibles from 14 rats (seven OVX and seven sham) were analyzed by micro-CT. Images of inter-radicular alveolar bone of the mandibular first molars underwent three-dimensional reconstruction and were analyzed.

Results

Compared to the sham group, trabecular thickness in OVX alveolar bone decreased by 27% (P = 0.012), but trabecular separation in OVX alveolar bone increased by 59% (P = 0.005). A thickness and separation map showed that trabeculae of less than 100μm increased by 46%, whereas trabeculae of more than 200μm decreased by more than 40% in the OVX group compared to those in the sham group. Furthermore, the OVX separation of those trabecular of more than 200μm was 65% higher compared to the sham group. Bone mineral density (P = 0.028) and bone volume fraction (p = 0.001) were also significantly decreased in the OVX group compared to the sham group.

Conclusions

Ovariectomy-induced bone loss in mandibular bone may be related to the distributional variations in trabecular thickness and separation which profoundly impact the modulation of the trabecular architecture.     

Dietary supplementation with Agaricus blazei murill extract prevents diet‐induced obesity and insulin resistance in rats

Objective:

Dietary supplement may potentially help to fight obesity and other metabolic disorders such as insulin‐resistance and low‐grade inflammation. The present study aimed to test whether supplementation with Agaricus blazei murill (ABM) extract could have an effect on diet‐induced obesity in rats.

Design and Methods:

Wistar rats were fed with control diet (CD) or high‐fat diet (HF) and either with or without supplemented ABM for 20 weeks.

Results:

HF diet‐induced body weight gain and increased fat mass compared to CD. In addition HF‐fed rats developed hyperleptinemia and insulinemia as well as insulin resistance and glucose intolerance. In HF‐fed rats, visceral adipose tissue also expressed biomarkers of inflammation. ABM supplementation in HF rats had a protective effect against body weight gain and all study related disorders. This was not due to decreased food intake which remained significantly higher in HF rats whether supplemented with ABM or not compared to control. There was also no change in gut microbiota composition in HF supplemented with ABM. Interestingly, ABM supplementation induced an increase in both energy expenditure and locomotor activity which could partially explain its protective effect against diet‐induced obesity. In addition a decrease in pancreatic lipase activity is also observed in jejunum of ABM‐treated rats suggesting a decrease in lipid absorption.

Conclusions:

Taken together these data highlight a role for ABM to prevent body weight gain and related disorders in peripheral targets independently of effect in food intake in central nervous system.     

Effects of the beta3 adrenergic receptor agonist on developmental obesity in oophorectomized rats.

In this study, we evaluated the anti-obesity effects of selective beta3 adrenergic receptor agonist (ARa) and/or a diet in oophorectomized (OVX) treatment in obese rats. Ten-week-old female Sprague-Dawley rats were divided into 4 groups: (1) OVX; (2) OVX treated with beta3 ARa, BRL 35 135; (3) sham-operated controls (sham group); (4) sham-treated with beta3 ARa (sham+ARa group). These four groups were divided into two groups, one on ad libitum diet, and the other on a diet of limited chow. The effects of beta3 ARa on body weight, intraabdominal fat weight, adipocyte volume, serum lipid content, and serum leptin were measured after 4 weeks had been completed. On both the ad libitum and the limited diet, ARa significantly reduced the ratio of intraabdominal fat and body weight (IAF ratio) regardless whether in the OVX or sham group, although ARa had no influence on weight gain. On the ad libitum diet, the serum leptin was significantly increased after OVX, and significantly reduced after ARa administration. ARa significantly reduced the volume of intraabdominal adipocytes. We conclude that ARa reduces intraabdominal fat without reducing body weight in oophorectomized rats. The serum parameter affected differently to rats on the ad libitum diet and on the limited diet.     

Antiosteoporotic activity of icariin in ovariectomized rats

Icariin was evaluated for its antiosteoporotic activity in an ovariectomized rat model of osteoporosis. The rats were divided into sham and OVX groups. The OVX rats were then subdivided into five groups treated with water, nylestriol (1 mg/kg body weight, weekly, orally) or icariin (ICA) (5, 25, and 125 mg/kg body weight, daily, orally) for 12 weeks. In OVX rats, the increases of body weight, serum BGP and ALP were significantly decreased by ICA treatment. In OVX rats, atrophy of uterus and descent of BMD were suppressed by treatment with ICA. In addition, ICA (125 mg/kg body weight) completely corrected the decreased serum concentration of Calcium, Phosphorus, and E₂ observed in OVX rats. ICA (125 mg/kg body weight) increased biomechanical strength significantly in comparison to the sham group. Histological results also showed its protective action through promotion of bone formation. The findings, assessed on the basis of biochemical, bone mineral density, biomechanical, and histopathological parameters, showed that ICA has a definite antiosteoporotic effect, similar to estrogen, especially effective for prevention bone fracture induced by estrogen deficiency.     

DHEA administration has limited effect onintestinal Ca absorption in ovariectomized rats

[Purpose]

The effect of dehydroepiandrosterone (DHEA) administration on intestinal Calcium (Ca) absorption in estrogen deficiency state has not been studied yet. We examined the bone mineral content (BMC) of lumbar spine and Ca balance such as intestinal Ca absorption and Ca accumulation in ovariectomized (OVX) rats after 8 weeks of DHEA administration.

[Methods]

Seventeen female Sprague-Dawley rats, 6 weeks old, were randomized into two groups: OVX control rats (OC, n = 8) and OVX rats with DHEA treatment (OD, n = 9). DHEA was administered to the OD group intraperitoneally at 20 mg DHEA/kg body weight for 8 weeks while the OC group was treated with vehicle only.

[Results]

The BMC normalized by body weight of the lumbar spine (trabecular-abundant region) in the OD group was found to be significantly higher compared to that in the OC group. The femoral wet weight normalized by body weight in the OD group was significantly higher compared to that in the OC group. The intestinal Ca absorption, rate of intestinal Ca absorption, Ca accumulation, and rate of Ca accumulation decreased from the 4th and 5th of the experimental diet period to the end of the experimental period, but interaction of time and group was not observed. In both periods, all parameters did not differ between the groups.

[Conclusion]

The present study confirmed the positive effect of DHEA on trabecular bone mass in ovariectomized rats. On the other hand, DHEA administration might have limited the impact on intestinal Ca absorption in estrogen deficiency state.     

Evaluation of the Preventive Effect of Isoflavone Extract on Bone Loss in Ovariectomized Rats

To examine a potential role for soybean phytoestrogens in postmenopausal bone loss, twenty-four 12-week-old Sprague-Dawley rats were divided randomly into 4 groups and given controlled diets for 16 weeks. The treatment groups were as followed: sham operated, ovariectomized (OVX) control, OVX + isoflavone extract (6.25 g/kg), and OVX + 17β-estradiol (4 mg/kg). OVX treatments reduced femoral and fourth lumbar vertebral bone density and mineral content (p<0.01), decreased uterine weight (p<0.01), accelerated body weight increases (p<0.05), and increased the activities (p<0.01) of both serum alkaline phosphatase (ALP) and tartrate-resistant acid phosphatase (TRAP). Supplementation with isoflavone prevented the losses of bone density and mineral content caused by OVX (p<0.01). Although both isoflavone and 17β-estradiol exhibited similar bone-sparing ability on the OVX-induced bone loss, the effect of isoflavone was not the same as that of 17β-estradiol on the serum ALP and TRAP, body weight increase, and uterine weight change. We concluded that dietary supplementation with soybean isoflavone can prevent postmenopausal bone loss via a different mechanism of estrogen in OVX rats.     

Evaluation of the preventive effect of isoflavone extract on bone loss in ovariectomized rats

To examine a potential role for soybean phytoestrogens in postmenopausal bone loss, twenty-four 12-week-old Sprague-Dawley rats were divided randomly into 4 groups and given controlled diets for 16 weeks. The treatment groups were as followed: sham operated, ovariectomized (OVX) control, OVX + isoflavone extract (6.25 g/kg), and OVX + 17beta-estradiol (4 mg/kg). OVX treatments reduced femoral and fourth lumbar vertebral bone density and mineral content (p<0.01), decreased uterine weight (p<0.01), accelerated body weight increases (p<0.05), and increased the activities (p<0.01) of both serum alkaline phosphatase (ALP) and tartrate-resistant acid phosphatase (TRAP). Supplementation with isoflavone prevented the losses of bone density and mineral content caused by OVX (p<0.01). Although both isoflavone and 17beta-estradiol exhibited similar bone-sparing ability on the OVX-induced bone loss, the effect of isoflavone was not the same as that of 17beta-estradiol on the serum ALP and TRAP, body weight increase, and uterine weight change. We concluded that dietary supplementation with soybean isoflavone can prevent postmenopausal bone loss via a different mechanism of estrogen in OVX rats.     

Carbohydrate-Free Peach (Prunus persica) and Plum (Prunus domestica) Juice Affects Fecal Microbial Ecology in an Obese Animal Model

Background

Growing evidence shows the potential of nutritional interventions to treat obesity but most investigations have utilized non-digestible carbohydrates only. Peach and plum contain high amounts of polyphenols, compounds with demonstrated anti-obesity effects. The underlying process of successfully treating obesity using polyphenols may involve an alteration of the intestinal microbiota. However, this phenomenon is not well understood.

Methodology/Principal Findings

Obese Zucker rats were assigned to three groups (peach, plum, and control, n = 10 each), wild-type group was named lean (n = 10). Carbohydrates in the fruit juices were eliminated using enzymatic hydrolysis. Fecal samples were obtained after 11 weeks of fruit or control juice administration. Real-time PCR and 454-pyrosequencing were used to evaluate changes in fecal microbiota. Over 1,500 different Operational Taxonomic Units at 97% similarity were detected in all rats. Several bacterial groups (e.g. Lactobacillus and members of Ruminococcacea) were found to be more abundant in the peach but especially in the plum group (plum juice contained 3 times more total polyphenolics compared to peach juice). Principal coordinate analysis based on Unifrac-based unweighted distance matrices revealed a distinct separation between the microbiota of control and treatment groups. These changes in fecal microbiota occurred simultaneously with differences in fecal short-chain acids concentrations between the control and treatment groups as well as a significant decrease in body weight in the plum group.

Conclusions

This study suggests that consumption of carbohydrate-free peach and plum juice has the potential to modify fecal microbial ecology in an obese animal model. The separate contribution of polyphenols and non-polyphenols compounds (vitamins and minerals) to the observed changes is unknown.     

不同干预疗法对去卵巢骨质疏松大鼠肱骨骨矿物质含量影响

目的:对比观察不同干预疗法对去卵巢骨质疏松大鼠肱骨骨矿物质含量的影响。方法:按体重将80只成年雌性SD大鼠分层后随机分为假手术组和去卵巢组。手术11周时,将去卵巢组大鼠按体重分层后又随机分为去卵巢组、跑台运动组、振动组、金雀异黄酮组、氯化锂组和雌激素组。跑台运动组每周进行4次45 min、速度18 m/min、跑道倾角5°的跑台训练;振动组每天进行2次15 min、频率90 HZ/min、7次/周的振动治疗;金雀异黄酮组每天按体重灌胃1次金雀异黄酮,剂量为1 mg/kg体重;氯化锂组每周按体重腹腔注射氯化锂3次,剂量为15 mg/kg;雌激素组每周按体重颈部皮下注射3次17β-雌二醇,剂量为25μg/kg。持续处理8周时,于末次处理结束36-48小时内,按解剖位置截取双肱骨,称量肱骨湿重、去脂肪干重以及煅烧后的灰重。结果:与假手术组比较,去卵巢组肱骨湿重/体重、去脂肪干重/体重和灰重/体重均显著下降;与去卵巢组比较,跑台运动组、振动组、金雀异黄酮组和雌激素组肱骨湿重/体重、去脂肪干重/体重、灰重/体重均显著增加,而氯化锂组虽有所升高,但差异无显著性。结论:除氯化锂处理外,其他几种处理均能减缓去卵巢骨质疏松大鼠肱骨骨量的丢失,对防治去卵巢骨质疏松大鼠的骨质疏松有一定的作用。     

PKCθ expression in the amygdala regulates insulin signaling,food intake and body weight

Objective:

To investigate the signaling mechanisms that might underlie the loss of anorectic response to insulin injections into the central nucleus of the amygdala (CeA) within 3 days of feeding a high fat diet.

Design and Methods:

Protein samples from amygdala and hypothalamus of rats fed high or low fat diets were subjected to a phosphorylation screening assay. The effects of dietary fat intake on the expression and activation of protein kinase C theta (PKCθ) in brain regions was studied. Finally, lentiviral vectors were used to overexpress rat PKCθ unilaterally or bilaterally into the CeA of rats and the effects on food intake, body weight and insulin stimulation of Akt phosphorylation were studied.

Results:

The level of pMARCKS (Myristoylated alanine‐rich C‐kinase substrate), a major substrate of PKCθ, was increased 116% in amygdala of high fat diet fed rats but reduced in the hypothalamus. High fat diets increased the level of PKCθ in a region specific manner in the brain and this PKCθ was activated by membrane association. Overexpressing rat PKCθ either unilaterally or bilaterally into the CeA inhibited insulin stimulation of Akt signaling and blocked the anorectic response to insulin injected into the amygdala. Bilaterally injected PKCθ rats gained more weight and body fat and had increased food intake when fed a high fat diet compared to the control rats that received a lentiviral‐Green Fluorescent Protein construct.

Conclusion:

The data suggest that insulin may have a physiological role within the amygdala to regulate energy balance.     

Effect of low‐level laser therapy and oxytocin on osteoporotic bone marrow‐derived mesenchymal stem cells

Postmenopausal osteoporosis (OP) is a major concern for public health. Low‐level laser therapy (LLLT) has a positive effect on the health of bone marrow mesenchymal stem cells (BMMSCs). The purpose of this study is to evaluate the influence of LLLT and oxytocin (OT) incubation—individually and in combination—on osteoporotic BMMSCs in ovariectomized rats. Twelve female rats were randomized into two groups to undergo either a sham surgery (sham group) or ovariectomy‐induced osteoporosis (OVX group). MSCs harvested from the BM of healthy and OVX rats underwent culture expansion. There were five groups. In Groups one (sham‐BMMSC) and two (OVX‐BMMSC) the cells were held in osteogenic condition medium without any intervention. In the group three (OT), OT incubation with optimum dose was performed for 48 h (two times, 10^?12 molar). In Group four, laser‐treated‐OVX‐BMMSCs were treated with optimum protocol of LLLT (one time, 1.2 J/cm²). In Group five (laser + OT group), the OT incubation plus the laser irradiation was performed. The biostimulatory effect of LLLT is demonstrated by a significant increase in the viability of OVX‐BMMSCs, cell cycle, and extracellular levels of Transforming growth factor beta (TGF‐β), insulin‐like growth factor‐I (IGF‐I), and Alkaline phosphatase (ALP) compared to control OVX‐BMMSCs and/or the sham group. OT incubation and laser + OT incubation have a positive effect on OVX‐BMMSCs. However, LLLT is more effective statistically. We conclude that LLLT significantly improved cell viability, enhanced the osteogenic potential of the OVX‐BMMSCs, and increased the extracellular levels of the TGF‐β, IGF‐I, and ALP.     

Predicting the effects of a high‐energy diet on fatty liver and hippocampal‐dependent memory in male rats

Objective:

In rodents, diets exceeding nutritional requirements (i.e., high‐energy diets; HED) impair hippocampal‐dependent memory. Our research suggests that the effects likely involve HED‐induced increases in liver lipids. In this experiment, rats were provided with diet choices to test whether voluntary consumption of a HED impairs spatial memory, whether differences in initial weight gain predict memory deficits, and whether increases in liver lipids are associated with the memory deficits.

Design and Methods:

Adult male Sprague‐Dawley rats were given a control diet or cafeteria‐style HED for 8 weeks. Weight gain during the first 5 days on the diet was used to divide rats into a HED‐Lean group and a HED‐Obese group. Spatial water maze memory was tested 8 weeks later and postmortem liver lipid concentrations were quantified.

Results:

Compared with the HED‐Lean and control rats, the HED‐Obese rats had impaired spatial memory and met the human diagnostic criterion of non‐alcoholic fatty liver disease (>5% liver lipids relative to liver weight). Moreover, liver lipids were correlated with memory deficits.

Conclusions:

These findings show that voluntary consumption of a HED impairs memory, that initial weight gain predicts fatty liver and memory deficits, and that fatty liver may contribute to the memory‐impairing effects of obesity.     

Combined Oral Administration of Bovine Collagen Peptides with Calcium Citrate Inhibits Bone Loss in Ovariectomized Rats

Purpose

Collagen peptides (CPs) and calcium citrate are commonly used as bone health supplements for treating osteoporosis. However, it remains unknown whether the combination of oral bovine CPs with calcium citrate is more effective than administration of either agent alone.

Methods

Forty 12-week-old Sprague-Dawley rats were randomly divided into five groups (n = 8) for once-daily intragastric administration of different treatments for 3 months at 3 months after ovariectomy (OVX) as follows: sham + vehicle; OVX + vehicle; OVX + 750 mg/kg CP; OVX + CP-calcium citrate (75 mg/kg); OVX + calcium citrate (75 mg/kg). After euthanasia, the femurs were removed and analyzed by dual energy X-ray absorptiometry and micro-computed tomography, and serum samples were analyzed for bone metabolic markers.

Results

OVX rats supplemented with CPs or CP-calcium citrate showed osteoprotective effects, with reductions in the OVX-induced decreases in their femoral bone mineral density. Moreover, CP-calcium citrate prevented trabecular bone loss, improved the microarchitecture of the distal femur, and significantly inhibited bone loss with increased bone volume, connectivity density, and trabecular number compared with OVX control rats. CP or CP-calcium citrate administration significantly increased serum procollagen type I N-terminal propeptide levels and reduced serum bone-specific alkaline phosphatase, osteocalcin, and C-telopeptide of type I collagen levels.

Conclusions

Our data indicate that combined oral administration of bovine CPs with calcium citrate inhibits bone loss in OVX rats. The present findings suggest that combined oral administration of bovine CPs with calcium citrate is a promising alternative for reducing bone loss in osteopenic postmenopausal women.     

The peroxisome proliferator-activated receptor (PPAR) alpha agonist fenofibrate maintains bone mass, while the PPAR gamma agonist pioglitazone exaggerates bone loss, in ovariectomized rats

Background

Activation of peroxisome proliferator-activated receptor (PPAR)gamma is associated with bone loss and increased fracture risk, while PPARalpha activation seems to have positive skeletal effects. To further explore these effects we have examined the effect of the PPARalpha agonists fenofibrate and Wyeth 14643, and the PPARgamma agonist pioglitazone, on bone mineral density (BMD), bone architecture and biomechanical strength in ovariectomized rats.

Methods

Fifty-five female Sprague-Dawley rats were assigned to five groups. One group was sham-operated and given vehicle (methylcellulose), the other groups were ovariectomized and given vehicle, fenofibrate, Wyeth 14643 and pioglitazone, respectively, daily for four months. Whole body and femoral BMD were measured by dual X-ray absorptiometry (DXA), and biomechanical testing of femurs, and micro-computed tomography (microCT) of the femoral shaft and head, were performed.

Results

Whole body and femoral BMD were significantly higher in sham controls and ovariectomized animals given fenofibrate, compared to ovariectomized controls. Ovariectomized rats given Wyeth 14643, maintained whole body BMD at sham levels, while rats on pioglitazone had lower whole body and femoral BMD, impaired bone quality and less mechanical strength compared to sham and ovariectomized controls. In contrast, cortical volume, trabecular bone volume and thickness, and endocortical volume were maintained at sham levels in rats given fenofibrate.

Conclusions

The PPARalpha agonist fenofibrate, and to a lesser extent the PPARaplha agonist Wyeth 14643, maintained BMD and bone architecture at sham levels, while the PPARgamma agonist pioglitazone exaggerated bone loss and negatively affected bone architecture, in ovariectomized rats.     

Chemically Defined Diet Alters the Protective Properties of Fructo-Oligosaccharides and Isomalto-Oligosaccharides in HLA-B27 Transgenic Rats

Non-digestible oligosaccharides (NDO) were shown to reduce inflammation in experimental colitis, but it remains unclear whether microbiota changes mediate their colitis-modulating effects. This study assessed intestinal microbiota and intestinal inflammation after feeding chemically defined AIN-76A or rat chow diets, with or without supplementation with 8 g/kg body weight of fructo-oligosaccharides (FOS) or isomalto-oligosaccharides (IMO). The study used HLA-B27 transgenic rats, a validated model of inflammatory bowel disease (IBD), in a factorial design with 6 treatment groups. Intestinal inflammation and intestinal microbiota were analysed after 12 weeks of treatment. FOS and IMO reduced colitis in animals fed rat chow, but exhibited no anti-inflammatory effect when added to AIN-76A diets. Both NDO induced specific but divergent microbiota changes. Bifidobacteria and Enterobacteriaceae were stimulated by FOS, whereas copy numbers of Clostridium cluster IV were decreased. In addition, higher concentrations of total short-chain fatty acids (SCFA) were observed in cecal contents of rats on rat chow compared to the chemically defined diet. AIN-76A increased the relative proportions of propionate, iso-butyrate, valerate and iso-valerate irrespective of the oligosaccharide treatment. The SCFA composition, particularly the relative concentration of iso-butyrate, valerate and iso-valerate, was associated (P≤0.004 and r≥0.4) with increased colitis and IL-1 β concentration of the cecal mucosa. This study demonstrated that the protective effects of fibres on colitis development depend on the diet. Although diets modified specific cecal microbiota, our study indicates that these changes were not associated with colitis reduction. Intestinal inflammation was positively correlated to protein fermentation and negatively correlated with carbohydrate fermentation in the large intestine.     

Detrimental effect of eicosapentaenoic acid supplementation on bone following ovariectomy in rats

Although several studies have reported a positive effect of n-3 essential fatty acids (EFAs) on bone density post-ovariectomy, the role of specific EFAs has yet to be fully elucidated. In this study, ovariectomised (OVX) rats were supplemented with 0.1 g (LOW) or 1.0 g (HIGH) of eicosapentaenoic acid (EPA)/kg body weight for 9 weeks. Bone mineral density (BMD), 25-hydroxyvitamin D(3) and plasma fatty acid profile were compared to those of OVX and sham animals fed a non-supplemented diet. BMD decreased significantly in all OVX (P<0.001) but not sham rats. There was no difference in BMD between the LOW group and OVX controls. BMD was significantly lower in the HIGH group compared to OVX and sham controls. 25-hydroxyvitamin D(3) levels were significantly higher in both the LOW and HIGH groups compared to OVX controls (P=0.0006 and 0.02, respectively). In conclusion, high-dose EPA supplementation exacerbated the effects of ovariectomy on BMD.     

Combined Effects of Phytoestrogen Genistein and Silicon on Ovariectomy-Induced Bone Loss in Rat

This study was performed to evaluate the effect of concomitant supplementation of genistein and silicon on bone mineral density and bone metabolism-related markers in ovariectomized rat. Three-month-old Sprague Dawley female rats were subjected to bilateral ovariectomy (OVX) or sham surgery, and then the OVX rats were randomly divided into four groups: OVX-GEN, OVX-Si, OVX-GEN-Si, and OVX. Genistein and silicon supplementation was started immediately after OVX and continued for 10 weeks. In the OVX-GEN group, 5 mg genistein per gram body weight was injected subcutaneously. The OVX-Si group was given soluble silicon daily in demineralized water (Si 20 mg/kg body weight/day). The OVX-GEN-Si group was given subcutaneous injections of 5 mg genistein per gram body weight, at the same time, given soluble silicon daily (Si 20 mg/kg body weight/day). The results showed that the genistein supplementation in the OVX rats significantly prevented the loss of uterus weight; however, the silicon supplementation showed no effect on the uterus weight loss. The lumbar spine and femur bone mineral density was significantly decreased after OVX surgery; however, this decrease was inhibited by the genistein and/or silicon, and the BMD of the lumbar spine and femur was the highest in the OVX-GEN-Si-treated group. Histomorphometric analyses showed that the supplementation of genistein and/or silicon restored bone volume and trabecular thickness of femoral trabecular bone in the OVX group. Besides, the treatment with genistein and silicon for 10 weeks increased the serum levels of calcium and phosphorus in the OVX rats; serum calcium and serum phosphorus in the OVX-GEN-Si group were higher than those in the OVX-GEN and OVX-Si group (P < 0.05). At the same time, the treatment with genistein and/or silicon decreased serum alkaline phosphatase (ALP) and osteocalcin, which were increased by ovariectomy; serum ALP and osteocalcin in the OVX-GEN-Si group were lower than those in the OVX-GEN and OVX-Si groups (P < 0.05). The results above indicate that genistein and silicon have synergistic effects on bone formation in ovariectomized rats.