Long-term Dietary Supplementation Research Articles

PSXIII-27 Effects of long-term dietary supplementation of nitrate on enteric methane production and performance of Hanwoo steers

Abstract Nitrate (NO3-) has been recognized as an effective dietary additive to reduce enteric methane (CH4) production in ruminants. Two experiments were performed to evaluate the effects of long-term supplementation and method of supplementing calcium ammonium nitrate (CAN) on enteric CH4 production in Hanwoo steers. In Exp. 1, Hanwoo steers [n = 20; body weight (BW) = 348 ± 18 kg] were divided into two groups of 10, and were assigned to one of the two diets 1) CON, 500 g/kg timothy hay and 500 g/kg commercial concentrate, or 2) CAN, basal diet top-dressed with 2.5% CAN [1.578% NO3- in the dietary dry matter (DM)] for 115 d in a completely randomized design. Measurement of CH4 was performed for 3 d starting from d 21, d 51, d 80 and d 112 using whole body respiratory chambers (RC). Rumen fluid and blood samples were collected on d 25 and d 26 of the feeding trial, respectively. In Exp. 2, the animals were re-grouped (476 ± 21 kg) and fed the same basal diet supplemented with 2.0% CAN (1.262% NO3- in the dietary DM) incorporated in the concentrate pellet (P-CAN). Methane was measured on d 19 and d 45 for 3 d. In Exp. 1, CAN supplementation decreased (P < 0.05) DM intake (DMI) of the steers both in the barn and RC. However, no negative effects on average daily gain or feed conversion ratio were observed. Also, no potential toxicity of NO3- was observed based on blood methemoglobin concentrations (all samples < 2.5% of total hemoglobin). A decrease (P < 0.05) in CH4 production (g/d) caused by decreased DMI was noted in CAN throughout the feeding trial. However, CH4 yield (g/kg DMI) decreased (P < 0.05) only in the beginning phase (d 21) and did not differ (P > 0.05) thereafter. Ruminal pH, ammonia and total volatile fatty acid concentration did not differ between treatments (P > 0.05), but CAN increased and decreased (P < 0.0001) acetate and butyrate proportions, respectively. Steers fed CAN had greater ruminal abundance of Ruminococcus sp. (P < 0.05), Succiniclasticum (P = 0.066), and Selenomonas ruminantium (P = 0.073), but a reduced (P < 0.05) abundance of Methanobrevibacter ruminantium (P = 0.073). In Exp. 2, P-CAN did not exert any effects on DMI, CH4 production, CH4 yield and other production parameters. Overall, CAN can be used as a feed additive for beef cattle in the long-term without NO3- intoxication or any negative effects on growth performance. However, lack of persistent decrease in CH4 yield suggested the need of further evaluation of CAN under different dietary conditions. Furthermore, incorporating CAN in the concentrate pellet can be a suitable approach, since top-dressing may alter the organoleptic properties of diets that may reduce DMI of the steers.

Effects of Long-Term Dietary High Vitamin D3 Supplementation on Cognition, the Brain Transcriptome and Microbiome in Male and Female Aging F344 Rats

Effects of Long-Term Dietary High Vitamin D3 Supplementation on Cognition, the Brain Transcriptome and Microbiome in Male and Female Aging F344 Rats

Effects of Long-Term Coated Sodium Butyrate Supplementation on the Intestinal Health and Colonization of Cecal Salmonella of Laying Hens Infected with Salmonella enteritidis.

Salmonella enterica ser. Enteritidis (S. Enteritidis) is widely found in chickens and eggs, and it can potentially induce human illness. The investigation in this study centers on the impacts of long-term dietary supplementation with coated sodium butyrate (CSB) on intestinal well-being and the colonization of cecum Salmonella in laying hens infected with S. Enteritidis. We segregated a total of 120 Lohmann laying hens aged 51 weeks into four treatment categories: 0 (CON), 300 (CSB1), 500 (CSB2), and 800 (CSB3) mg/kg of CSB, supplemented with CSB from the first day of the experiment. A 24-week observation process was carried out for each laying hen. The S. Enteritidis was orally administered to all chickens on the morning of the first and third days of week 22 of the trial. After the S. Enteritidis challenge, egg production decreased the most in the CON group. Compared to the CON group, the three doses of CSB significantly improved egg production after the S. Enteritidis challenge (PANOVA < 0.05). S. Enteritidis challenge increased plasma DAO activity, but CSB supplementation reduced plasma DAO activity (Plinear < 0.05). The S. Enteritidis challenge disrupted intestinal villi morphology; compared to the CON group, the three dosages of CSB resulted in an increase in villus height (VH) and the ratio of villus height to crypt depth (V/C) in the duodenum, jejunum, and ileum of infected laying hens (Plinear < 0.05), with a significant increase in jejunal villus height (PANOVA < 0.05). A decrease in ileal crypt depth was also observed (Plinear < 0.05). CSB2 and CSB3 markedly increased the content of butyric acid in the cecum (PANOVA < 0.05). Additionally, in contrast to those in the CON group, the propionic acid content in the CSB supplementation group increased (Plinear < 0.05). Compared with those in the CON group, mRNA relative expression of the IL-6 and IL-1β in jejunum (Plinear < 0.05) and mRNA relative expression of the IL-1β in ileum (PANOVA < 0.05) were significantly lower, and mRNA relative expression of the IL-10 in ileum (Plinear < 0.05) were significantly higher in the CSB group. In addition, in contrast to the CON group, the CSB supplementation group significantly upregulated mRNA relative expression of the ZO-1 and CLDN1 (PANOVA < 0.05). Additionally, CSB supplementation reduced the number of Salmonella and increased the number of Lactobacilli in the cecum (Plinear < 0.05) and tended to increase the total bacteria count (Plinear = 0.069) and reduce the E. coli count (Plinear = 0.081). In conclusion, long-term dietary supplementation with coated sodium butyrate can alleviate intestinal injury and the colonization of cecum Salmonella in laying hens infected with S. Enteritidis.

Effects of extended dietary supplementation with Santalum album essential oil on hemato-biochemical changes, innate immune response, antioxidant status, and expression of related gene in Nile tilapia (Oreochromis niloticus).

The effects of long-term dietary supplementation with sandalwood (Santalum album L.) essential oil (SEO) was investigated on hemato-biochemical biomarkers, immune status, antioxidant capacity, and resistance against Staphylococcus aureus in Nile tilapia (Oreochromis niloticus). Five groups (with four replicates) of O. niloticus (12.60 ± 0.20 g) were fed diets supplemented with SEO at doses of 0, 0.5, 1.0, 2.0, and 4.0 mL/kg diet for 60 days. Results indicated a substantial increase in blood protein levels and lower serum cholesterol, cortisol, glucose, urea, creatinine levels and, transaminase activities of fish fed a 2.0-mL SEO/kg diet. Serum lysozyme activity, nitric oxide, complement-3 levels, and phagocytic activity were significantly improved in O. niloticus after 60 days of feeding SEO-supplemented diets. Dietary SEO at level of 2.0-mL SEO/kg diet increased the activities of SOD, CAT, and GPx, and decreased MDA levels in liver homogenate. In addition, dietary 2.0-mL SEO/kg diet significantly upregulated antioxidant genes expression (CAT, SOD, GPx, GST, and GSR) with downregulation of apoptotic genes (HSP70, TLR2, caspase-3, and PCNA) in the liver. Furthermore, SEO-enriched diets significantly down-regulated pro-inflammatory (TNF-α, IL-1β, and IL-8) and up-regulated anti-inflammatory cytokine genes (TFG-β and IL-10) in the spleen. Moreover, SEO fortification increased the relative percentage of survival against S. aureus challenge and regulated immune-antioxidant genes in the spleen after the challenge. Overall, the results revealed that long-term using SEO might strengthen the physiological performance, hepatic oxidant/antioxidant balance, innate immune response, and resistance of O. niloticus against bacterial infections.

Long-term intake of Lactobacillushelveticus enhances bioavailability of omega-3 fatty acids in the mouse retina

Omega-3 (n-3) polyunsaturated fatty acids (PUFAs), particularly docosahexaenoic acid (DHA), are required for the structure and function of the retina. Several observational studies indicate that consumption of a diet with relatively high levels of n-3 PUFAs, such as those provided by fish oils, has a protective effect against the development of age-related macular degeneration. Given the accumulating evidence showing the role of gut microbiota in regulating retinal physiology and host lipid metabolism, we evaluated the potential of long-term dietary supplementation with the Gram-positive bacterium Lactobacillus helveticus strain VEL12193 to modulate the retinal n-3 PUFA content. A set of complementary approaches was used to study the impact of such a supplementation on the gut microbiota and host lipid/fatty acid (FA) metabolism. L. helveticus-supplementation was associated with a decrease in retinal saturated FAs (SFAs) and monounsaturated FAs (MUFAs) as well as an increase in retinal n-3 and omega-6 (n-6) PUFAs. Interestingly, supplementation with L. helveticus enriched the retina in C22:5n-3 (docosapentaenoic acid, DPA), C22:6n-3 (DHA), C18:2n-6 (linoleic acid, LA) and C20:3n-6 (dihomo gamma-linolenic acid, DGLA). Long-term consumption of L. helveticus also modulated gut microbiota composition and some changes in OTUs abundance correlated with the retinal FA content. This study provides a proof of concept that targeting the gut microbiota could be an effective strategy to modulate the retinal FA content, including that of protective n-3 PUFAs, thus opening paths for the design of novel preventive and/or therapeutical strategies for retinopathies.

Preventive effects of a nutraceutical mixture of berberine, citrus and apple extracts on metabolic disturbances in Zucker fatty rats.

The prevention of obesity represents a major health and socio-economic challenge. Nutraceuticals are regularly highlighted for their beneficial effects in preventing the metabolic disturbances associated with obesity. However, few studies have described the combined action of nutraceutical mixtures combining polyphenols with alkaloids. The aim of this study was to evaluate the effects of long-term dietary supplementation with a mixture of Berberine, Citrus and Apple extracts (BCA) in the primary prevention of obesity and its metabolic and vascular complications in the obese Zucker rat, a spontaneous model of genetic obesity and insulin resistance. Sixteen 8-week-old obese Zucker male rats were randomly divided into two groups: all rats received oral gavage daily either with water, untreated obese (U-ObZ) or BCA (BCA-ObZ) mixture for thirteen weeks. Morphological and metabolic parameters were measured along the study. Cumulative concentration-response curves to insulin, acetylcholine and phenylephrine were determined on isolated thoracic aorta. Colon permeability measurements were performed using the Ussing chamber technique. Fecal samples collected at the beginning and the end of the protocol were used as a template for amplification of the V3-V4 region of the 16S rDNA genes. BCA supplementation reduced weight gain (p<0.05) and food intake (p<0.05) in the BCA-ObZ group rats compared to the U-ObZ group rats. It also improved glucose tolerance (p<0.001) and decreased fasting insulin and Homeostasis model assessment index (p<0.05). Through ex vivo experiments, the BCA mixture enhanced significantly aortic insulin relaxation (p<0.01), reduced α1-adrenoceptor-mediated vasoconstriction (p<0.01), and decreased distal colon permeability. Moreover, short-chain fatty acid producers such as Bacteroides, Blautia, and Akkermansia were found to be increased by the BCA mixture supplementation. The results showed that a 13-week-supplementation with BCA mixture prevented weight gain and improved glucose metabolism in obese Zucker rats. We also demonstrated that BCA supplementation improved vascular function, colonic barrier permeability and gut microbiota profile.

Long-term supplementation with EPA and DHA changes the fatty acid profile of rat tissues, upregulates NRF2 expression and downregulates TGFβ expression

We studied the influence of long-term treatment with eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) on the liver, and kidney lipogenesis, inflammation and antioxidative gene expression. Male Wistar rats were divided into three groups on the basis of the different n6/n3 fatty acid ratios achieved by using different dietary oil blends: the control (CON, n6/n3 ratio was ~7), the N6 group (n6/n3 ratio was ~50) and the DHA group (n6/n3 ~1). Treatment significantly influenced the fatty acid profile of the liver and kidney tissues. The most characteristic changes were an increased content of EPA and DHA in the DHA group in both tissues, of the kidney and liver. The expression of transforming growth factor beta (TGF-ß) was downregulated in the liver tissue by long-term EPA/DHA supplementation. This could be attributed to a decrease in the production of arachidonic acid-derived proinflammatory mediators, and an increase in EPA and DHA derived eicosanoids. DHA and EPA supplementation also significantly increased expression of the NRF 2 gene. This finding suggests that n3 PUFA could influence the activation of the NRF 2 pathway, which is important in cell antioxidative defense. In conclusion, we have shown that long-term dietary supplementation with DHA and EPA could influence lipid metabolism, inflammation and antioxidative defense. Therefore, the long-term addition of dietary DHA and EPA could potentially influence the most important pathological processes in aging.

Comparative Effects of Vitamin A and E Dietary Supplements on Semen Traits, Reproductive System Morphology and Vitamin Storage in Rooster

The purpose of this study was to determine the effect of long-term vitamin A and E dietary supplements on the semen traits and morphology of the reproductive system in older roosters to prolong their reproductive contributions to the flock. The research revealed that long-term dietary supplementation of both vitamins A and E maintained the traits of the semen at levels significantly higher than in the control roosters. Vitamin A especially maintained ejaculate volume and semen density, while vitamin E protected semen motility and viability. Vitamin A treatment maintained the uniformity of the epididymal epithelium. No eroded areas were identified in this epithelium. Most epithelial cells were principal cells with uniform stereocilia. The connective tissue which lines the epididymal tubule of the vitamin A treated rooster was thinner than those of the roosters from the control. Vitamin E predominantly protected the structure of the spermatogenesis line. Liver tissue concentrations of vitamins A and E were two times and four times higher respectively than the control. The two vitamins were eliminated in increased quantities through the seminal plasma in supplemented roosters. No mutual inhibition or potentiating effects were found between the two vitamins, suggesting that their combined administration should be further analyzed.

Effect of long-term dietary supplementation with lavender, Lavandula angustifolia, oil on European seabass growth performance, innate immunity, antioxidant status, and organ histomorphometry

Effect of long-term dietary supplementation with lavender, Lavandula angustifolia, oil on European seabass growth performance, innate immunity, antioxidant status, and organ histomorphometry

Dietary Supplementation with Yerba Mate (Ilex paraguariensis) Infusion Increases IRS-1 and PI3K mRNA Levels and Enhances Insulin Sensitivity and Secretion in Rat Pancreatic Islets.

"Yerba mate" (YM), an aqueous extract of Ilex paraguariensis, has antioxidant, diuretic, cardio-protective and hypoglycaemic properties. Since its effect on the pancreatic islets remains unclear, we evaluated insulin sensitivity and glucose-stimulated insulin secretion (GSIS) in rats consuming YM or tap water (C) for 21 days. Glucose tolerance, glycemia, triglyceridemia, insulinemia, TBARS and FRAP serum levels were evaluated. GSIS and mRNA levels of insulin signaling pathway and inflammatory markers were measured in isolated pancreatic islets from both groups. In C rats, islets were incubated with YM extract or its phenolic components to measure GSIS. YM improved glucose tolerance, enhanced GSIS, increased FRAP plasma levels and islet mRNA levels of IRS-1 and PI3K (p110), and decreased TBARS plasma levels and islet gene expression of TNF-α and PAI-1. Islets from C rats incubated with 100 µg/mL dry YM extract, 1 µM chlorogenic acid, 0.1 and 1 µM rutin, 1 µM caffeic acid or 1 µM quercetin showed an increase in GSIS. Our results suggest that YM enhances glucose tolerance because of its positive effects on GSIS, oxidative stress rate and insulin sensitivity in rat islets, suggesting that long-term dietary supplementation with YM may improve glucose homeostasis in pre-diabetes or type 2 diabetes.

Impact of heat stress length and dietary antioxidant supplementation on the nutrient digestibility, metabolism and immune response of fattening pigs

Study aimed to investigate the impact of long-term high ambient temperature (HAT) exposure and dietary antioxidant supplementation (elevated levels and in combination) on nutrient digestibility, metabolism and immune response of pigs. A total of 36 Danbred barrows (65.1 ± 2.81 kg) were allotted to four treatments: Trm1: HAT (28.9 ± 0.9 °C) + control diet (CD); Trm2: HAT + elevated vitamin C and E and Se and Zn; Trm3: HAT + further elevated vitamin C and E and Se and Zn; and Trm4: thermo-neutral ambient temperature (19.5 ± 0.9 °C) + CD. Nutrients (DM, CP, Cfat, CF, CA, GE) and minerals (Ca, P, Na, Zn, Se) digestibility were determined. Plasma metabolite and cytokine concentrations were investigated from the blood samples collected on d 15 and 28. Heat shock proteins (HSP 70 and 90) and tumor necrosis factor-alpha (TNF-α) expressions were investigated from jejunum samples of pigs. HAT did not significantly affect pigs' nutrient digestibility and retention (P > 0.05). However, Trm2 pigs had greater digestibility in terms of DM, CF, Ca, Zn, Se and retention of Ca, Zn, Na, and Se than Trm1 and Trm4 groups. Trm3 pigs had significantly higher (P < 0.05) creatinine concentrations than Trm4 pigs. HAT did not significantly affect the expression of cytokines; however, vitamins and micro-minerals supplementation in the diet significantly (P < 0.05) improved interleukin (IL) 10 expression, reduced TNF-α, and HSP70 expressions. Vitamin and micro-mineral fortified diet can improve pigs' nutrient and mineral digestibility and could alleviate inflammatory response in pigs exposed to HAT.

Long-term dietary folic acid supplementation attenuated aging-induced hippocampus atrophy and promoted glucose uptake in 25-month-old rats with cognitive decline

The brain has high energy demand making it sensitive to changes in energy fuel supply. Aging shrinks brain volume, decreases glucose uptake availability of the brain, and finally, causes cognitive dysfunction. Folic acid supplementation delayed cognitive decline and neurodegeneration. However, whether folic acid affects brain energy metabolism and structural changes is unclear. The study aimed to determine if long-term dietary folic acid supplementation could alleviate age-related cognitive decline by attenuating hippocampus atrophy and promoting brain glucose uptake in Sprague-Dawley (SD) rats. According to folic acid levels in diet, 3-months old male SD rats were randomly divided into four intervention groups for 22 months in equal numbers: folic acid-deficient diet (FA-D) group, folic acid-normal diet (FA-N) group, low folic acid-supplemented diet (FA-L) group, and high folic acid-supplemented diet (FA-H) group. The results showed that serum folate concentrations decreased and serum homocysteine (Hcy) concentrations increased with age, and dietary folic acid supplementation increased serum folate concentrations and decreased Hcy concentrations at 11, 18, and 22 months of intervention. Dietary folic acid supplementation attenuated aging-induced hippocampus atrophy, which was showed by higher fractional anisotropy and lower mean diffusivity in the hippocampus, increased brain 18F-Fluorodeoxyglucose (18F-FDG) uptake, then stimulated neuronal survival, and alleviated age-related cognitive decline in SD rats. In conclusion, long-term dietary folic acid supplementation alleviated age-related cognitive decline by attenuating hippocampus atrophy and promoting brain glucose uptake in SD rats.

Long-term dietary nitrate supplementation slows the progression of established atherosclerosis in ApoE−/− mice fed a high fat diet

Background and aimsAtherosclerosis is associated with a reduction in the bioavailability and/or bioactivity of endogenous nitric oxide (NO). Dietary nitrate has been proposed as an alternate source when endogenous NO production is reduced. Our previous study demonstrated a protective effect of dietary nitrate on the development of atherosclerosis in the apoE−/− mouse model. However most patients do not present clinically until well after the disease is established. The aims of this study were to determine whether chronic dietary nitrate supplementation can prevent or reverse the progression of atherosclerosis after disease is already established, as well as to explore the underlying mechanism of these cardiovascular protective effects.Methods60 apoE−/− mice were given a high fat diet (HFD) for 12 weeks to allow for the development of atherosclerosis. The mice were then randomized to (i) control group (HFD + 1 mmol/kg/day NaCl), (ii) moderate-dose group (HFD +1 mmol/kg/day NaNO3), or (iii) high-dose group (HFD + 10 mmol/kg/day NaNO3) (20/group) for a further 12 weeks. A group of apoE−/− mice (n = 20) consumed a normal laboratory chow diet for 24 weeks and were included as a reference group.ResultsLong-term supplementation with high dose nitrate resulted in ~ 50% reduction in plaque lesion area. Collagen expression and smooth muscle accumulation were increased, and lipid deposition and macrophage accumulation were reduced within atherosclerotic plaques of mice supplemented with high dose nitrate. These changes were associated with an increase in nitrite reductase as well as activation of the endogenous eNOS-NO pathway.ConclusionLong-term high dose nitrate significantly attenuated the progression of established atherosclerosis in the apoE−/− mice fed a HFD. This appears to be mediated in part through a XOR-dependent reduction of nitrate to NO, as well as enhanced eNOS activation via increased Akt and eNOS phosphorylation.

Long-Term Dietary Supplementation with Betaine Improves Growth Performance, Meat Quality and Intramuscular Fat Deposition in Growing-Finishing Pigs.

This study was designed to investigate the effects of dietary betaine supplementation on growth performance, meat quality and muscle lipid metabolism of growing-finishing pigs. Thirty-six crossbred pigs weighing 24.68 ± 0.97 kg were randomly allotted into two treatments consisting of a basal diet supplemented with 0 or 1200 mg/kg betaine. Each treatment included six replications of three pigs per pen. Following 119 days of feeding trial, dietary betaine supplementation significantly enhanced average daily gain (ADG) (p < 0.05) and tended to improve average daily feed intake (ADFI) (p = 0.08) and decreased the feed intake to gain ratio (F/G) (p = 0.09) in pigs during 100~125 kg. Furthermore, a tendency to increase ADG (p = 0.09) and finial body weight (p = 0.09) of pigs over the whole period was observed in the betaine diet group. Betaine supplementation significantly increased a*45 min and marbling and decreased b*24 h and cooking loss in longissimus lumborum (p < 0.05), tended to increase intramuscular fat (IMF) content (p = 0.08), however had no significant influence on carcass characteristics (p > 0.05). Betaine supplementation influenced the lipid metabolism of pigs, evidenced by a lower serum concentration of low-density lipoprotein cholesterol (p < 0.05), an up-regulation of mRNA abundance of fatty acid synthase and acetyl-CoA carboxylase (p < 0.05), and a down-regulation of mRNA abundance of lipolysis-related genes, including the silent information regulators of transcription 1 (p = 0.08), peroxisome proliferator-activated receptorα (p < 0.05), peroxisome proliferator-activated receptor gamma coactivator-1α (p = 0.07) and carnitine palmitoyl transferase 1 (p < 0.05) in longissimus lumborum. Moreover, betaine markedly improved the expression of microRNA-181a (miR-181a) (p < 0.05) and tended to enhance miR-370 (p = 0.08). Overall, betaine supplementation at 1200 mg/kg could increase the growth performance of growing-finishing pigs. Furthermore, betaine had a trend to improve meat quality and IMF content via increasing lipogenesis and down-regulating the abundance of genes associated with lipolysis, respectively, which was associated with the regulation of miR-181a and miR-370 expression by betaine.

Chronic dietary supplementation with nicotinamide riboside reduces sleep need in the laboratory mouse.

Non-rapid eye movement sleep (NREMS) is accompanied by a reduction in cerebral glucose utilization. Enabling this metabolic change may be a central function of sleep. Since the reduction in glucose metabolism is inevitably accompanied by deceleration of downstream oxidation/reduction reactions involving nicotinamide adenine dinucleotide (NAD), we hypothesized a role for NAD in regulating the homeostatic dynamics of sleep at the biochemical level. We applied dietary nicotinamide riboside (NR), a NAD precursor, in a protocol known to improve neurological outcome measures in mice. Long-term (6-10 weeks) dietary supplementation with NR reduced the time that mice spent in NREMS by 17 percent and accelerated the rate of discharge of sleep need according to a mathematical model of sleep homeostasis (Process S). These findings suggest that increasing redox capacity by increasing nicotinamide availability reduces sleep need and increases the cortical capacity for energetically demanding high-frequency oscillations. In turn, this work demonstrates the impact of redox substrates on cortical circuit properties related to fatigue and sleep drive, implicating redox reactions in the homeostatic dynamics of cortical network events across sleep-wake cycles.

Urolithin A reduces amyloid-beta load and improves cognitive deficits uncorrelated with plaque burden in a mouse model of Alzheimer’s disease

In the present study, we investigated the effects of urolithin A (UA), a metabolite generated from ellagic acid via its metabolism by gut bacteria, as an autophagy activator with potential neuroprotective activity. WT and 3xTg-AD mice were administered long-term intermittent dietary supplementation with UA. UA was found to prevent deficits in spatial memory, cued fear response, and exploratory behavior in this model. It also decreased the Aβ plaque burden in areas of the hippocampus where these protein deposits are prominent in the model. Interestingly, correlation analyses demonstrate that Aβ plaque burden positively correlates with enhanced spatial memory in 3xTg-AD mice on a control diet but not in those supplemented with UA. In contrast, Aβ42 abundance in cortical and hippocampal homogenates negatively correlate with spatial memory in UA-fed mice. Our data suggest that plaque formation may be a protective mechanism against neurodegeneration and cognitive decline and that targeting the generation of proteotoxic Aβ species might be a more successful approach in halting disease progression. UA was also found to extend lifespan in normal aging mice. Mechanistically, we demonstrate that UA is able to induce autophagy and to increase Aβ clearance in neuronal cell lines. In summary, our studies reveal UA, likely via its actions as a autophagy inducer, is capable of removing Aβ from neurons and its dietary administration prevents the onset of cognitive deficits associated with pathological Aβ deposition in the 3xTg-AD mouse model as well as extending lifespan in normal aging mice.

Effects of daidzein on antioxidant capacity in weaned pigs and IPEC-J2 cells.

Our previous study found that soybean isoflavones in soybean meal play an important role in improving growth performance and antioxidant capacity in pigs. However, it is still unknown whether long-term supplementation with daidzein, an active molecule deglycosylated from daidzin, in a corn–soybean meal diet can enhance growth performance in pigs. Thus, in the present study, an animal trial was carried out to investigate the effects of dietary supplementation with daidzein on the growth performance and antioxidant capacity of pigs. A total of 80 weaned piglets (40 barrows and 40 females) were assigned to 4 treatments with 5 pens per treatment and 4 piglets per pen and fed a diet supplemented with 0, 25, 50 and 100 mg/kg daidzein for a 72-day trial. In addition, porcine intestinal epithelial cells (IPEC-J2) were used as an in vitro model to explore the underlying antioxidant mechanisms of daidzein. IPEC-J2 cells were treated with 0.6 mM hydrogen peroxide (H2O2) in the presence or absence of 40 μM daidzein. The results showed that adding 50 mg/kg of daidzein to the diet significantly improved body weight on day 72, average daily gain (ADG) during days 0 to 72 and plasma superoxide dismutase (SOD) activity on day 42 (P < 0.05). Treatment with 0.6 mM H2O2 for 1 h significantly decreased cell viability and catalase (CAT) activity and increased intracellular reactive oxygen species (ROS) levels and malondialdehyde (MDA) content (P < 0.05), while pretreatment with 40 μM daidzein prevented the decrease in cell viability and CAT activity and the increase in intracellular ROS levels and MDA content caused by H2O2 (P < 0.05). In addition, H2O2 stimulation significantly suppressed the expression of nuclear factor erythroid-2-related factor 2 (Nrf2), CAT, occludin and zonula occludens-1 (ZO-1), while pretreatment with daidzein preserved the expression of Nrf2, CAT and occludin in H2O2-stimulated IPEC-J2 cells (P < 0.05). In conclusion, our results suggested that long-term dietary supplementation with 50 mg/kg daidzein improved growth performance in pigs and was beneficial to the antioxidant capacity of pigs. Daidzein exerted protective effects against H2O2-induced oxidative stress in IPEC-J2 cells and the underlying mechanism may be related to the activation of the Nrf2 signaling pathway.

Effects of long-term dietary supplementation of fermented wheat bran on immune performance and inflammatory response in laying hens

ABSTRACT This study was conducted to investigate the effects of solid-state fermented wheat bran on immune performance and inflammatory response in laying hens. A total of 225 18-week-old Hy-Line brown-egg laying hens were randomly divided into 3 groups with 5 replicates per group and 15 hens per replicate. Laying hens were fed a basal diet (corn-soybean meal diet) supplemented with 0 (control group), 10% wheat bran and 10% fermented wheat bran, respectively. The results showed: (1) Compared to wheat bran group, the contents of crude protein, trichloroacetic acid-soluble protein, dietary fibre (DF), mannan and total polyphenols in wheat bran were increased by solid state fermentation. (2) Compared to the control group, fermented wheat bran increased the levels of serum biochemical parameters, reproductive hormones, immunoglobulins and anti-inflammatory factors. Therefore, long-term dietary supplementation of 10% fermented wheat bran plays an important role in improving the immune performance of laying hens.

Pyrroloquinoline quinone ameliorates diabetic cardiomyopathy by inhibiting the pyroptosis signaling pathway in C57BL/6 mice and AC16 cells

PurposeDiabetic cardiomyopathy (DCM), a common complication of diabetes mellitus and is characterized by myocardial hypertrophy and myocardial fibrosis. Pyrroloquinoline quinone (PQQ), a natural nutrient, exerts strong protection against various myocardial diseases. Pyroptosis, a type of inflammation-related programmed cell death, is vital to the development of DCM. However, the protective effects of PQQ against DCM and the associated mechanisms are not clear. This study aimed to investigate whether PQQ protected against DCM and to determine the underlying molecular mechanism.MethodsDiabetes was induced in mice by intraperitoneal injection of streptozotocin, after which the mice were administered PQQ orally (10, 20, or 40 mg/kg body weight/day) for 12 weeks. AC16 human myocardial cells were divided into the following groups and treated accordingly: control (5.5 mmol/L glucose), high glucose (35 mmol/L glucose), and HG + PQQ groups (1 and 10 nmol/L PQQ). Cells were treated for 24 h.ResultsPQQ reduced myocardial hypertrophy and the area of myocardial fibrosis, which was accompanied by an increase in antioxidant function and a decrease in inflammatory cytokine levels. Moreover, myocardial hypertrophy—(ANP and BNP), myocardial fibrosis—(collagen I and TGF-β1), and pyroptosis-related protein levels decreased in the PQQ treatment groups. Furthermore, PQQ abolished mitochondrial dysfunction and the activation of NF-κB/IκB, and decreased NLRP3 inflammation-mediated pyroptosis in AC16 cells under high-glucose conditions.ConclusionPQQ improved DCM in diabetic mice by inhibiting NF-κB/NLRP3 inflammasome-mediated cell pyroptosis. Long-term dietary supplementation with PQQ may be greatly beneficial for the treatment of DCM.Graphical abstractDiagram of the underlying mechanism of the effects of PQQ on DCM. PQQ inhibits ROS generation and NF-κB activation, which stimulates activation of the NLRP3 inflammasome and regulates the expression of caspase-1, IL-1β, and IL-18. The up-regulated inflammatory cytokines trigger myocardial hypertrophy and cardiac fibrosis and promote the pathological process of DCM.

Dietary fat quality impacts metabolic impairments of type 2 diabetes risk differently in male and female CD-1® mice.

Metabolic impairments associated with type 2 diabetes, including insulin resistance and loss of glycaemic control, disproportionately impact the elderly. Lifestyle interventions, such as manipulation of dietary fat quality (i.e. fatty acid (FA) composition), have been shown to favourably modulate metabolic health. Yet, whether or not chronic consumption of beneficial FAs can protect against metabolic derangements and disease risk during ageing is not well defined. We sought to evaluate whether long-term dietary supplementation of fish-, dairy- or echium-derived FAs to the average FA profile in a U.S. American diet may offset metabolic impairments in males and females during ageing. One-month-old CD-1® mice were fed isoenergetic, high-fat (40 %) diets with the fat content composed of either 100 % control fat blend (CO) or 70 % CO with 30 % fish oil, dairy fat or echium oil for 13 months. Every 3 months, parameters of glucose homoeostasis were evaluated via glucose and insulin tolerance tests. Glucose tolerance improved in males consuming a diet supplemented with fish oil or echium oil as ageing progressed, but not in females. Yet, females were more metabolically protected than males regardless of age. Additionally, Spearman correlations were performed between indices of glucose homoeostasis and previously reported measurements of diet-derived FA content in tissues and colonic bacterial composition, which also revealed sex-specific associations. This study provides evidence that long-term dietary fat quality influences risk factors of metabolic diseases during ageing in a sex-dependent manner; thus, sex is a critical factor to be considered in future dietary strategies to mitigate type 2 diabetes risk.