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Beta-hydroxy-beta-methylbutyrate (HMB) is a leucine metabolite with protein anabolic effects. We examined the effects of an HMB-enriched diet in healthy rats and rats with liver cirrhosis induced by multiple doses of carbon tetrachloride (CCl4). HMB increased branched-chain amino acids (BCAAs; valine, leucine and isoleucine) in blood and BCAA and ATP in muscles of healthy animals. The effect on muscle mass and protein content was insignificant. In CCl4-treated animals alterations characteristic of liver cirrhosis were found with decreased ratio of the BCAA to aromatic amino acids in blood and lower muscle mass and ATP content when compared with controls. In CCl4-treated animals consuming HMB, we observed higher mortality, lower body weight, higher BCAA levels in blood plasma, higher ATP content in muscles, and lower ATP content and higher cathepsin B and L activities in the liver when compared with CCl4-treated animals without HMB. We conclude that (1) HMB supplementation has a positive effect on muscle mitochondrial function and enhances BCAA concentrations in healthy animals and (2) the effects of HMB on the course of liver cirrhosis in CCl4-treated rats are detrimental. Further studies examining the effects of HMB in other models of hepatic injury are needed to determine pros and cons of HMB in the treatment of subjects with liver cirrhosis., (© 2019 The Authors. International Journal of Experimental Pathology © 2019 International Journal of Experimental Pathology.)

Objectives: This study aims to investigate the effects and roles of excess leucine (Leu) versus its metabolites α-ketoisocaproate (KIC) and β-hydroxy-β-methyl butyrate (HMB) on fatty acid composition and lipid metabolism in skeletal muscle of growing pigs., Methods and Results: Thirty-two pigs with a similar initial weight (9.55 ± 0.19 kg) were fed one of the four diets (basal diet, L-Leu, KIC-Ca and HMB-Ca) for 45 days. Results indicated that dietary treatments did not affect the intramuscular fat (IMF) content (p > 0.05), but differently influenced the fatty acid composition of longissimus dorsi muscle (LM) and soleus muscle (SM). In particular, the proportion of N3 PUFA specifically in LM was significantly decreased in the Leu group and increased in both KIC and HMB group relative to the basal diet group (p < 0.05). Furthermore, pigs fed KIC-supplemented diets exhibited decreased expression of FATP-1, ACC, ATGL, C/EBPα, PPARγ and SREBP-1c in LM and increased expression of FATP-1, FAT/CD36, ATGL and M-CPT-1 in SM relative to the basal diet control (p < 0.05)., Conclusions: These findings indicated that doubling dietary Leu content decreased the percentage of N3 PUFA mainly in glycolytic skeletal muscle, whereas KIC and HMB improved muscular fatty acid composition and altered lipid metabolism in skeletal muscle of growing pigs. The mechanism of action of KIC might be related to the TFs, and the mechanism of action of HMB might be associated with the AMPK-mTOR signalling pathway., (© 2019 Blackwell Verlag GmbH.)

Objective: This study investigated the effect of β-hydroxy-β-methylbutyrate (HMB) supplementation for either 2 or 4 weeks on the muscle damage after elbow flexors after eccentric contractions (ECCs)., Methods: Twenty-eight untrained men were completed the double-blind, placebo-controlled, parallel design study. The subjects were randomly assigned to the ingestion of HMB supplement for 2 weeks (HMB 2-week, n = 10), for 4 weeks (HMB 4-week, n = 10), or a placebo group (PL, n = 8). Subjects of HMB 2-week and HMB 4-week consumed 3 g HMB per day, and they performed 6 sets of 10 ECCs at 100% maximal voluntary contraction (MVC) using a dumbbell. Changes in MVC torque, range of motion (ROM), upper arm circumference, muscle soreness, and muscle stiffness were assessed before, immediately after, and 1, 2, and 5 days after exercise., Results: MVC torque and ROM were significantly higher in the HMB 2-week and HMB 4-week groups than in the PL group after ECCs (p < 0.05). The upper arm circumference was significantly smaller in the HMB 2- and 4-week groups than in the PL group after ECCs (p < 0.05). In addition, muscle stiffness at 150° was significantly lower in the HMB 2- and 4-week groups than in the PL group at immediately after ECCs (p < 0.05). However, there was no difference in all outcomes between HMB 2-week and HMB 4-week., Conclusion: We concluded that more than 2 weeks of HMB supplementation has a positive role for untrained subjects to prevent the muscle damage after ECCs.

Objectives: Mitochondrial dysfunction in skeletal muscle has emerged as key to the development of obesity and its related metabolic disorders. Leucine (Leu) is an essential amino acid that has been reported to increase mitochondrial biogenesis in muscle cells, as has its metabolite β-hydroxy-β-methylbutyrate (HMB). However, two questions-which one is more potent and what is the cellular mechanisms of the action of Leu and HMB-remain to be answered. Therefore we aimed to investigate the effects of Leu and HMB on mitochondrial function in C2 C12 myotubes and analyze the underlying molecular mechanism., Methods and Results: The effects of Leu and HMB on mitochondrial mass, mitochondrial respiration capacity, and the expression of genes related to mitochondrial biogenesis were evaluated in C2 C12 myotubes. Differentiated myotubes were treated with Leu (0.5 mM) or HMB (50 μM) with or without PPARβ/δ antagonist (GSK3787, 1 μM) and CDK4 antagonist (LY2835219, 1.5 μM), respectively, for 24 h. The results indicated that treatment with Leu or HMB significantly increased mitochondrial mass, mitochondrial respiration capacity, and the messenger RNA expression of genes associated with mitochondrial biogenesis (P < 0.05). In addition, these positive effects of Leu or HMB on these parameters were attenuated by GSK3787 and LY2835219 treatments (P < 0.05)., Conclusions: Our results provide evidence indicating that as with Leu, HMB alone could increase mitochondrial biogenesis and function via regulation of PPARβ/δ and CDK4 pathways. Moreover, HMB seems to be more potent than Leu in the positive regulation of mitochondrial biogenesis and function in C2 C12 myotubes because the dosage used for HMB was much lower than that for Leu., (Copyright © 2018 Elsevier Ltd. All rights reserved.)

Beta-hydroxy-beta-methylbutyrate (HMB) is a leucine metabolite with protein anabolic effects. This study was designed to determine whether prenatal HMB treatment has an effect on oogenesis and folliculogenesis in the ovary of newborn piglets. HMB decreased the number of egg nests and primordial follicles and increased the pool of developing follicles compared to the control group. Although the percentage of TUNEL-positive oocytes within the egg nests was higher in HMB-treated group no increase in the Bax/Bcl-2 ratio and active caspase-3 expression was observed. Moreover, the granulosa cell proliferation index and StAR protein expression were higher in HMB-treated group. In contrast to the control group, the expression of E-cadherins was reduced after the HMB treatment. In addition, a significant increase in the serum level of gonadotropins and steroid hormones was detected in HMB-treated piglets. In conclusion, prenatal HMB treatment dysregulates hormonal homeostasis which impairs early folliculogenesis in piglets., (Copyright © 2019. Published by Elsevier Inc.)

Background/aim: Stress reactions, especially those related to surgery, cause poor convalescence of cancer patients. β-Hydroxyβ-methylbutyrate (HMB) is known to regulate excessive inflammation in the body. The objective of this work was to investigate the capacity of HMB to suppress activation of nuclear factor-kappa B (NF-ĸB) and production of interleukin-6 (IL-6) in a human esophageal squamous cell carcinoma cell line (TE-1)., Materials and Methods: Cell proliferation was measured using the water-soluble tetrazolium-1 method, while tumor necrosis factor alpha (TNFα)-induced IL-6 production was measured using an enzyme-linked immunosorbent assay (ELISA) assay. Nuclear translocation of NF-ĸB was detected by immunofluorescence staining., Results: HMB did not affect cell proliferation. However, HMB suppressed the TNFα-induced increase in IL-6 production in TE-1 cells by inhibiting NF-ĸB activation., Conclusion: HMB did not influence TE-1 cell proliferation, but inhibited activation of NF-ĸB and IL-6 production. This result may be useful for improving excessive stress reactions during and after surgery., (Copyright© 2019, International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.)

The study was conducted on 26 male, 30 days-old goats, separated from their mothers, divided into two equal groups: I - control and II - experimental, consisting of 13 animals each. All animals were fed with milk replacer, experimental group received additionally 50 g/kg body weight, additive of HMB, for 60 days. The following features were analyzed: body weight, daily increases of body weight, as well as hematological and biochemical blood features. Differences in body weight were found, between experimental and control group, after 60 days of experiment 0.57 kg (p≤0.01). The daily weight gain of experimental animals was higher in comparison with control group. Significant differences were also noted in results of hematological and biochemical blood parameters. Experimental animals showed a higher level of red blood cells as well as number of lymphocytes in comparison with the control group, (p≤0.01).Significant changes were also observed in the level of triglycerides, inorganic phosphorus and protein between both groups. The acid-base balance parameters and ionogram, showed a higher pH level (p≤0.05) HCO - act., HCO - std., BE, ctCO , O sat, K+, Cl- (p≤0.01), while the anion gap (AG) and Na+ were significantly lower in control group (p≤0.01)., (Copyright© by the Polish Academy of Sciences.)

It has been demonstrated in animal studies that prenatal administration of β-hydroxy-β-methylbutyrate (HMB, metabolite of leucine) influences general growth and mechanical endurance of long bones in newborn offspring in sex-dependent manner. The present experiment was conducted to evaluate the effect of HMB treatment of pregnant sows on bone development in offspring at weaning. From 70th day until the 90th day of gestation, sows received either a basal diet (n = 12) or the same diet supplemented with HMB (n = 12) at the dose of 0.2 g/kg of body weight/day. Femora obtained from six males and females in each group weaned at the age of 35 days were examined. Maternal HMB treatment significantly enhanced body weight and changed bone morphology increasing femur mechanical strength in both sexes. Maternal HMB supplementation also elevated bone micro- and macroelement concentrations and enhanced content of proteoglycans in articular cartilage. Based on the obtained results, it can be concluded that maternal HMB supplementation in the mid-gestation period significantly accelerated bone development in both sexes by upregulation of a multifactorial system including leptin and osteoprotegerin. However, the sex (irrespective of the HMB treatment) was the factor which influenced the collagen structure in cartilages and trabecular bone, as demonstrated both by the Picrosirius red staining and performed analysis of thermal stability of collagenous tissues. The structural differences in collagen between males and females were presumably related to a different collagen maturity. No studies conducted so far provided a detailed morphological analysis of bone, articular cartilage, growth plate and the activities of the somatotropic and pituitary-gonadal axes, as well as leptin/osteoprotegerin system in weaned offspring prenatally treated with HMB. This study showed also the relationship between the maternal HMB treatment and bone osteometric and mechanical traits, hormones, and growth and bone turnover markers such as leptin, osteoprotegerin and insulin-like growth factor-1., (© 2019 Blackwell Verlag GmbH.)

Short-chain fatty acids (SCFAs) have immunomodulatory effects, but the underlying mechanisms are not well understood. Here we show that pentanoate, a physiologically abundant SCFA, is a potent regulator of immunometabolism. Pentanoate induces IL-10 production in lymphocytes by reprogramming their metabolic activity towards elevated glucose oxidation. Mechanistically, this reprogramming is mediated by supplying additional pentanoate-originated acetyl-CoA for histone acetyltransferases, and by pentanoate-triggered enhancement of mTOR activity. In experimental mouse models of colitis and multiple sclerosis, pentanoate-induced regulatory B cells mediate protection from autoimmune pathology. Additionally, pentanoate shows a potent histone deacetylase-inhibitory activity in CD4 + T cells, thereby reducing their IL-17A production. In germ-free mice mono-colonized with segmented filamentous bacteria (SFB), pentanoate inhibits the generation of small-intestinal Th17 cells and ameliorates SFB-promoted inflammation in the central nervous system. Taken together, by enhancing IL-10 production and suppressing Th17 cells, the SCFA pentanoate might be of therapeutic relevance for inflammatory and autoimmune diseases.

Most of reported steroidal FXR antagonists are restricted due to low potency. We described the design and synthesis of novel nonsteroidal scaffold SIPI-7623 derivatives as FXR antagonists. The most potent compound A-11 (IC 50  = 7.8 ± 1.1 μM) showed better activity compared to SIPI-7623 (IC 50  = 40.8 ± 1.7 μM) and guggulsterone (IC 50  = 45.9 ± 1.1 μM). Docking of A-11 in FXR's ligand-binding domain was also studied.

Oral intake of beta-hydroxy-beta-methylbutyrate (HMB), arginine, and glutamine may ameliorate muscle loss by stimulating protein synthesis and decreasing protein degradation while simultaneously decreasing inflammation. Previous studies provide evidence for improvement in body composition with dietary supplementation of these ingredients among patients with muscle-wasting diseases. The objectives of this study were to examine the effects of this amino acid mixture on lean body mass, muscle volume, and physical function among healthy older adults. Thirty-one community-dwelling men and women, aged 65-89 years, were randomized to either two oral doses of the amino acid supplement (totaling 3 g HMB, 14 g arginine, 14 g glutamine) or placebo daily for six months. At baseline and month six, lean body mass was measured by air displacement plethysmography, dual-energy X-ray absorptiometry (DXA), and four-compartment model. Muscle volume of quadriceps was quantified by magnetic resonance imaging (MRI), and participants performed a battery of tests to assess physical function. As compared to the placebo group, the treatment group exhibited improvement in a timed stair climb (p =.016) as well as significant increases in lean body mass by all methods of assessment (p <.05). Regional analysis by DXA revealed increased arm lean mass in the supplement group only (p =.035). However, no change was observed in MRI-derived quadriceps volume. Dietary supplementation with HMB, arginine, and glutamine improved total body lean mass among a small sample of healthy older adults. Further research is indicated to elucidate mechanisms of action and to determine whether supplementation may benefit frail elders. Registered under ClinicalTrials.gov identifier no. NCT01057082.

To investigate the effect of in ovo feeding (IOF) of beta-hydroxy beta-methylbutyrate (HMB), dextrin and post-hatching water and feed deprivation time on growth performance of broilers, 1,500 eggs were assigned into 15 experimental runs of Box-Behnken design, including three levels IOF of HMB (0%, 0.5% and 1%), dextrin (0%, 20% and 40%) and three levels of the first water and feed deprivation (6, 27 and 48 hr). After hatching, day-old chicks (seven males and seven females) from each replicate were then selected and randomly assigned to 60 floor pens for a 42-day feeding trial. The experimental data were fitted to the quadratic response surface models, and the goodness of fit of the models was expressed by the R 2 value. The interaction between IOF of dextrin and timing of first feed deprivation had the largest effect on body weight of chicks at day 7 (BW7) and corrected European production efficiency factor (EPEF). In ovo feeding of dextrin reduced negative effects of delayed access to feed and water after hatch up to 48 hr on BW7, body weight of chicks at day 42, EPEF and corrected EPEF. The results of the current study suggested that the EPEF corrected by hatchability could provide the better understanding of IOF experimental findings. The ridge optimization analysis revealed that the optimal levels of HMB and dextrin inclusion in eggs and timing of first feed deprivation for maximum corrected EPEF were 0.37, 15.94% and 7.22 hr, respectively. These results demonstrate that the Box-Behnken statistical design and response surface models are effective to describe the relationship between IOF of nutrients and pre-placement holding time and predict the performance of broilers to achieve the optimal target., (© 2018 Blackwell Verlag GmbH.)

Background & Aims: Fecal microbiota transplantation (FMT) is effective for treating recurrent Clostridioides difficile infection (CDI), but there are concerns about its long-term safety. Understanding the mechanisms of the effects of FMT could help us design safer, targeted therapies. We aimed to identify microbial metabolites that are important for C difficile growth., Methods: We used a CDI chemostat model as a tool to study the effects of FMT in vitro. The following analyses were performed: C difficile plate counts, 16S rRNA gene sequencing, proton nuclear magnetic resonance spectroscopy, and ultra-performance liquid chromatography and mass spectrometry bile acid profiling. FMT mixtures were prepared using fresh fecal samples provided by donors enrolled in an FMT program in the United Kingdom. Results from chemostat experiments were validated using human stool samples, C difficile batch cultures, and C57BL/6 mice with CDI. Human stool samples were collected from 16 patients with recurrent CDI and healthy donors (n = 5) participating in an FMT trial in Canada., Results: In the CDI chemostat model, clindamycin decreased valerate and deoxycholic acid concentrations and increased C difficile total viable counts and valerate precursors, taurocholic acid, and succinate concentrations. After we stopped adding clindamycin, levels of bile acids and succinate recovered, whereas levels of valerate and valerate precursors did not. In the CDI chemostat model, FMT increased valerate concentrations and decreased C difficile total viable counts (94% decrease), spore counts (86% decrease), and valerate precursor concentrations; concentrations of bile acids were unchanged. In stool samples from patients with CDI, valerate was depleted before FMT but restored after FMT. Clostridioides difficile batch cultures confirmed that valerate decreased vegetative growth, and that taurocholic acid was required for germination but had no effect on vegetative growth. Clostridioides difficile total viable counts were decreased by 95% in mice with CDI given glycerol trivalerate compared with phosphate buffered saline., Conclusions: We identified valerate as a metabolite that is depleted with clindamycin and only recovered with FMT. Valerate is a target for a rationally designed recurrent CDI therapy., (Copyright © 2018 AGA Institute. Published by Elsevier Inc. All rights reserved.)

Background: Growing evidence suggests beta-hydroxy-beta-methylbutyrate's (HMB) positive effects on recovery following exercise-induced muscle damage (EIMD). However, findings vary substantially across studies., Objective: A meta-analysis of randomized controlled trials was conducted to assess the effects of HMB supplementation on recovery following EIMD by assessing indirect markers of muscle damage, namely creatine kinase (CK) and lactate dehydrogenase (LDH) serum levels among healthy participants., Method: A comprehensive search was performed on electronic databases (Medline, Scopus, Cochrane Library, and Google Scholar) up to October 2017 for trials evaluating the effects of HMB on recovery following EIMD. Mean ± standard deviation of follow-up CK and LDH concentrations were extracted to calculate the effect size for meta-analysis., Results: A total of 324 participants for CK and 229 participants for LDH were found from the 10 and 8 studies, respectively. The results revealed a significant effect of HMB supplementation on CK (weighted mean difference [WMD] = -60.71 UL -1 ; 95% confidence interval [CI], -78.12 to -43.29; I 2 = 4.1%; p heterogeneity = 0.40) and LDH reduction (WMD = -15.42 UL -1 ; 95% CI, -22.2 to -8.6; I 2 = 0.0%; p heterogeneity = 0.53). In addition, a subgroup analysis based on study duration (< 6 weeks vs. ≥ 6 weeks) suggested that HMB effectiveness on EIMD was statistically significant in studies over 6 weeks (p < 0.001)., Conclusions: The current evidence revealed a time-dependent effect of HMB in reducing LDH and CK serum levels among adults. HMB, therefore, may be seen as a priority muscle damage recovery agent in interventions.

Purpose: This phase II trial assessed the clinical benefit of beta-hydroxy-beta-methylbutyrate, arginine, and glutamine (HMB/Arg/Gln) for preventing chemoradiotherapy (CRT)-induced oral mucositis (OM) in patients with head and neck cancer (HNC)., Methods: Patients with HNC receiving definitive or postoperative cisplatin-based CRT were enrolled. HMB/Arg/Gln was administered orally or per percutaneous endoscopic gastrostomy from the first day of CRT up to its completion. All patients received opioid-based pain control and oral care programs that we previously reported. The primary endpoint was the incidence of grade ≥ 3 OM (functional/symptomatic) according to the Common Terminology Criteria of Adverse Events version 3.0. Quality of life (EORTC QLQ-C30/PROMS) at baseline and upon radiotherapy at a dosage of 50 Gy were assessed., Results: Thirty-five patients with HNC were enrolled. Sixteen of them (45.7%) developed grade ≥ 3 OM (i.e., functional/symptomatic). The incidence of grade ≤ 1 OM (functional/symptomatic) was 51.5% at 2 weeks and 82.9% at 4 weeks after radiotherapy completion. Clinical examination revealed that 10 patients (28.6%) developed grade ≥ 3 OM. The incidence of grade ≤ 1 OM (clinical exam) was 80.0% at 2 weeks and 100% at 4 weeks after radiotherapy completion. Adverse events related to HMB/Arg/Gln were an increase in blood urea nitrogen and diarrhea, but were easily managed., Conclusions: The addition of HMB/Arg/Gln to opioid-based pain control and oral care programs was feasible but still insufficient at reducing the incidence of CRT-induced severe OM. However, the benefit of HMB/Arg/Gln should not be neglected given the findings of clinical examinations and the rapid recovery from severe OM., Trial Registration: UMIN000016453.

Objectives: The aim of this meta-analysis was to examine the evidence for the effectiveness of beta-hydroxy-beta-methylbutyrate supplementation interventions on modification in strength and body composition in trained and competitive athletes., Design: Systematic review and meta-analysis., Methods: A systematic search was performed using three databases: MEDLINE, EBSCO and Web of Science. The analysis was restricted to randomized controlled trials that examined the effect of HMB supplementation interventions on modification in bench and leg press strength, body mass, fat-free mass and fat mass. Effect sizes (ES) and 95% confidence intervals (CIs) were calculated using a fixed effect meta-analysis due to low value of the heterogeneity. The Egger test was used to determine the presence of publication bias, and the Q and I 2 statistics were used to assess heterogeneity among studies. Significance was set at p<0.05., Results: Six studies were selected for meta-analysis, as they fulfilled the inclusion criteria (n=193 participants). HMB supplementation interventions present a trivial non-significant ES in all variables studied (bench press ES=0.00, leg press ES=0.09, body mass ES=-0.01, fat-free mass ES=0.16, and fat mass ES=-0.20; all cases p>0.05, and null heterogeneity I 2 =0.0% p>0.05). These results remained constant even analyzing by subgroups (HMB doses, duration of intervention, training level and diet co-intervention)., Conclusions: This meta-analysis found no effect of HMB supplementation on strength and body composition in trained and competitive athletes., (Copyright © 2017 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.)

The release of ADP from platelet dense granules and its binding to platelet P2Y 12 receptors is key to amplifying the initial hemostatic response and propagating thrombus formation. P2Y 12 has thus emerged as a therapeutic target to safely and effectively prevent secondary thrombotic events in patients with acute coronary syndrome or a history of myocardial infarction. Pharmacological inhibition of P2Y 12 receptors represents a useful approach to better understand the signaling mediated by these receptors and to elucidate the role of these receptors in a multitude of platelet hemostatic and thrombotic responses. The present work examined and compared the effects of four different P2Y 12 inhibitors (MRS2395, ticagrelor, PSB 0739, and AR-C 66096) on platelet function in a series of in vitro studies of platelet dense granule secretion and trafficking, calcium generation, and protein phosphorylation. Our results show that in platelets activated with the PAR-1 agonist TRAP-6 (thrombin receptor-activating peptide), inhibition of P2Y 12 with the antagonist MRS2395, but not ticagrelor, PSB 0739 or AR-C 66096, potentiated human platelet dense granule trafficking to the plasma membrane and release into the extracellular space, cytosolic Ca 2+ influx, and phosphorylation of GSK3β-Ser9 through a PKC-dependent pathway. These results suggest that inhibition of P2Y 12 with MRS2395 may act in concert with PAR-1 signaling and result in the aberrant release of ADP by platelet dense granules, thus reducing or counteracting the anticipated anti-platelet efficacy of this inhibitor.

Purpose of Review: β-Hydroxy β-methylbutyrate (HMB) has been used for many years in athletes for muscle buildup and strength, and endurance enhancement. In recent years, its interest quickly expanded in older (diseased) populations and during (exercise) rehabilitation and recovery from hospitalization and surgery. We will discuss recent literature about HMB metabolism, its pharmacokinetics compared with the frequently used metabolite leucine, effectiveness of HMB to improve outcome in older diseased adults, and novel approaches for HMB use., Recent Findings: HMB supplementation resulted in positive outcomes on muscle mass and functionality, related to its anabolic and anticatabolic properties and prolonged half-life time in blood. Furthermore, it was able to increase the benefits of (exercise) rehabilitation programs to enhance recovery from illness or medical procedures. There is promising evidence that HMB might support bone density, improve cognitive function, and reduce abdominal obesity, which is of importance particularly in the older (diseased) population., Summary: The older diseased population might benefit from dietary HMB because of its established positive properties as well as its long lasting (pharmacological) effect. In addition to evaluating its efficacy and application in various clinical conditions, more research is needed into the mechanisms of action, the optimal dosage, and its potential additional beneficial effects on outcome.

A Box-Behnken design (BBD) in a response surface methodology (RSM) was used to investigate the response of broiler chicks to in ovo feeding (IOF) of beta-hydroxy beta-methylbutyrate (HMB), dextrin and the timing of the first water and feed deprivation. On day 18th of incubation, 1,500 eggs were randomly assigned to 15 experimental runs of BBD, each with 4 replicates, as 3 levels IOF of HMB (0%, 0.5% and 1%) and dextrin (0%, 20% and 40%), and 3 levels of the first water and feed deprivation (6, 27 and 48 hr). Day-old chicks from each replicate were then used to assess the effect of IOF and time first water and feed access on chick's responses. The IOF of dextrin leads to respectively 9.7%-15.5% lower hatchability for 20% and 40% inclusion (p < .05), whereas HMB inclusion appeared with no effect on hatchability (p > .05). Administration of dextrin or HMB into the amnion of embryos elevated length, width and surface area of villus, and increased glycogen content of liver and breast (p < .05). In all parameter models, the linear terms showed highest contribution (R 2  = 0.81-0.97) to explain existing variation in chick's responses. The first water and feed deprivation had largest effect on BW2 and glycogen content of liver and breast. It is concluded that if possible, place chicks before 7 hr of hatch to preserve BW loss and have maximum response from IOF. If not possible, use IOF with 40% dextrin + 0.5% HMB to preserve gut integrity and energy status up to 48 hr. This should give advantage to chicks to recover fast after feeding, but that would have to be confirmed by trials growing birds to slaughter age., (© 2017 Blackwell Verlag GmbH.)

This study was a randomised, double-blind, placebo-controlled cross-over trial examining the effects of β-hydroxy β-methylbutyrate free acid (HMB-FA) supplementation on muscle protein breakdown, cortisol, testosterone and resting energy expenditure (REE) during acute fasting. Conditions consisted of supplementation with 3 g/d HMB-FA or placebo during a 3-d meat-free diet followed by a 24-h fast. Urine was collected before and during the 24-h fast for analysis of 3-methylhistidine:creatinine ratio (3MH:CR). Salivary cortisol, testosterone, their ratio (T:C), and the cortisol awakening response were assessed. ANOVA was used to analyse all dependent variables, and linear mixed models were used to confirm the absence of carryover effects. Eleven participants (six females, five males) completed the study. Urinary HMB concentrations confirmed compliance with supplementation. 3MH:CR was unaffected by fasting and supplementation, but the cortisol awakening response differed between conditions. In both conditions, cortisol increased from awakening to 30 min post-awakening (P=0·01). Cortisol was reduced from 30 to 45 min post-awakening with HMB-FA (-32 %, d=-1·0, P=0·04), but not placebo (PL) (-6 %, d=-0·2, P=0·14). In males, T:C increased from 0 to 24 h of fasting with HMB-FA (+162 %, d=3·0, P=0·001), but not placebo (+13 %, d=0·4, P=0·60), due to reductions in cortisol. REE was higher at 24 h of fasting than 16 h of fasting independent of supplementation (+4·0 %, d=0·3, P=0·04). In conclusion, HMB-FA may affect cortisol responses, but not myofibrillar proteolysis, during acute 24-h fasting.

Beta-hydroxy-beta-methylbutyrate (HMB), a leucine metabolite, enhances the gain of skeletal muscle mass by increasing protein synthesis or attenuating protein degradation or both. The aims of this study were to investigate the effect of HMB on molecular factors controlling skeletal muscle protein synthesis and degradation, as well as muscle contractile function, in fed and fasted conditions. Wistar rats were supplied daily with HMB (320 mg/kg body weight diluted in NaCl-0.9%) or vehicle only (control) by gavage for 28 days. After this period, some of the animals were subjected to a 24-h fasting, while others remained in the fed condition. The EDL muscle was then removed, weighed and used to evaluate the genes and proteins involved in protein synthesis (AKT/4E-BP1/S6) and degradation (Fbxo32 and Trim63). A sub-set of rats were used to measure in vivo muscle contractile function. HMB supplementation increased AKT phosphorylation during fasting (three-fold). In the fed condition, no differences were detected in atrogenes expression between control and HMB supplemented group; however, HMB supplementation did attenuate the fasting-induced increase in their expression levels. Fasting animals receiving HMB showed improved sustained tetanic contraction times (one-fold) and an increased muscle to tibia length ratio (1.3-fold), without any cross-sectional area changes. These results suggest that HMB supplementation under fasting conditions increases AKT phosphorylation and attenuates the increased of atrogenes expression, followed by a functional improvement and gain of skeletal muscle weight, suggesting that HMB protects skeletal muscle against the deleterious effects of fasting.

All motile organisms use spatially distributed chemical features of their surroundings to guide their behaviors, but the neural mechanisms underlying such behaviors in mammals have been difficult to study, largely due to the technical challenges of controlling chemical concentrations in space and time during behavioral experiments. To overcome these challenges, we introduce a system to control and maintain an olfactory virtual landscape. This system uses rapid flow controllers and an online predictive algorithm to deliver precise odorant distributions to head-fixed mice as they explore a virtual environment. We establish an odor-guided virtual navigation behavior that engages hippocampal CA1 "place cells" that exhibit similar properties to those previously reported for real and visual virtual environments, demonstrating that navigation based on different sensory modalities recruits a similar cognitive map. This method opens new possibilities for studying the neural mechanisms of olfactory-driven behaviors, multisensory integration, innate valence, and low-dimensional sensory-spatial processing.

The purpose of this review is to discuss the structural and physiological changes that underlie age-related neuromuscular dysfunction and to summarize current evidence on the potential role of nutritional interventions on neuromuscular dysfunction-associated pathways. Age-related neuromuscular deficits are known to coincide with distinct changes in the central and peripheral nervous system, in the neuromuscular system, and systemically. Although many features contribute to the age-related decline in neuromuscular function, a comprehensive understanding of their integration and temporal relationship is needed. Nonetheless, many nutrients and ingredients show promise in modulating neuromuscular output by counteracting the age-related changes that coincide with neuromuscular dysfunction. In particular, dietary supplements, such as vitamin D, omega-3 fatty acids, β-hydroxy-β-methylbutyrate, creatine, and dietary phospholipids, demonstrate potential in ameliorating age-related neuromuscular dysfunction. However, current evidence seldom directly assesses neuromuscular outcomes and is not always in the context of aging. Additional clinical research studies are needed to confirm the benefits of dietary supplements on neuromuscular function, as well as to define the appropriate population, dosage, and duration for intervention., (Copyright © 2018 The Authors. Published by Elsevier Inc. All rights reserved.)

The aim of the study was to evaluate the effect of the diet, mother type and sex of the offspring on the mechanical and geometric parameters of long bones as well as bone tissue density in minks. Primiparous and multiparous dams were supplemented with β-hydroxy β-methylbutyrate (a metabolite of leucine, at the daily dosage of 0.02 g/kg of body weight) and/or 2-oxoglutaric acid (a precursor of glutamine, at the daily dosage of 0.4 g/kg of body weight) during gestation. The diet did not influence bone tissue density and the length of the humerus. An increase in the length of the femur was noted in male offspring delivered by multiparous dams. The diet resulted in an increase in the weight of the humerus in males from multiparous dams and a decrease in offspring from primiparous dams. Heavier femora were noted in male offspring delivered by both types of dams. The maximum elastic strength of the humerus was higher in the offspring delivered by multiparous than primiparous dams, irrespective of the offspring sex. The diet resulted in reduction in the ultimate strength of the femur in the male offspring delivered by primiparous dams. Only females born by multiparous dams, irrespective of the diet, showed a significant increase in the cross-sectional area of the humerus, while a significant decline was noted in males delivered by multiparous dams and in all the offspring delivered by primiparous dams. An increase in the cross-sectional area of the femur was noted in the offspring delivered by multiparous dams, while reduction was observed in the offspring delivered by primiparous dams. These results have shown for the first time that the presence of β-hydroxy-β-methylbutyrate or 2-oxoglutaric acid in the diet of pregnant primiparous or multiparous dams unambiguously affects the geometry and mechanical properties of offspring's long bones., (© 2017 Blackwell Verlag GmbH.)

Background: Interleukin-6 (IL-6) is an inflammatory cytokine. Whether systemic IL-6 affects atrogene expression and disuse-induced skeletal muscle atrophy is unclear., Methods: Tail-suspended mice were used as a disuse-induced muscle atrophy model. We administered anti-mouse IL-6 receptor antibody, beta-hydroxy-beta-methylbutyrate (HMB) and vitamin D to the mice and examined the effects on atrogene expression and muscle atrophy., Results: Serum IL-6 levels were elevated in the mice. Inhibition of IL-6 receptor suppressed muscle RING finger 1 (MuRF1) expression and prevented muscle atrophy. HMB and vitamin D inhibited the serum IL-6 surge, downregulated the expression of MuRF1 and atrogin-1 in the soleus muscle, and ameliorated atrophy in the mice., Conclusion: Systemic IL-6 affects MuRF1 expression and disuse-induced muscle atrophy.

Leucine (Leu) and its metabolites α-ketoisocaproate (KIC) and β-hydroxy-β-methyl butyrate (HMB) are potent regulators of protein turnover. The aim of this study was to compare the inhibitory effects of Leu, KIC, and HMB on protein degradation and to investigate the mechanisms involved. The results showed that the inhibitory effect of HMB (0.38 ± 0.04) was more potent than that of Leu (0.76 ± 0.04) and KIC (0.56 ± 0.04, P < 0.01), and was significantly abolished in the presence of LY294002 (1.48 ± 0.02) and rapamycin (1.96 ± 0.02, P < 0.01). In the presence of insulin, the inhibitory effect of HMB (0.34 ± 0.03) was still more effective than that of Leu (0.60 ± 0.04) and KIC (0.57 ± 0.08, P < 0.05). Interestingly, LY294002 treatment markedly attenuated the effect of HMB, while rapamycin treatment failed to exert the same effect. Thus, HMB appears to be more potent than Leu and KIC in inhibiting protein degradation in the absence or presence of insulin, and this inhibitory effect may be dependent on PI3K/Akt signaling pathway regardless of insulin, and mTOR signaling was only involved in this effect of HMB in the absence of insulin.

β-hydroxy-β-methylbutyrate (HMB) is a metabolite derived from leucine and its ketoacid alpha- ketoisocaproate. Leucine has a role in regulating protein synthesis in muscle cells, and HMB seems to be a key active metabolite in such regulation. HMB has been shown to modulate muscle protein degradation by inhibiting the ubiquitin-proteasome proteolytic pathway, to up-regulate protein synthesis via the mTOR pathway, and to stabilize cell membranes via the rate limiting enzyme to cholesterol synthesis HMG- coenzyme A reductase. It can also decrease cell apoptosis, therefore improving cell survival; and increase proliferation and differentiation of muscle stem cell, via the MAPK/ERK and PI3K/Akt pathways. HMB is widely used as an ergogenic supplement by athletes and bodybuilders, usually combined with exercise training, to increase muscle mass and strength. Some studies have explored the role of HMB in chronic diseases associated with muscle wasting (cancer, acquired immunodeficiency syndrome, chronic obstructive pulmonary disease). This review focuses on the role of HMB in the management of sarcopenia (age or disease-related loss of muscle mass and function) in older persons. A small number of studies have shown increases in lean (muscle) mass and some muscle function and physical performance parameters in older people with or without resistance exercise, and preservation of muscle mass during bed rest. However, heterogeneous methodological approaches preclude solid conclusions, and more studies are needed to confirm the role of HMB as a promising agent to treat sarcopenia., (Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.)

McIntosh, ND, Love, TD, Haszard, J, Osborne, H, and Black, KE. β-hydroxy β-methylbutyrate (HMB) supplementation effects on body mass and performance in elite male rugby union players. J Strength Cond Res 32(1): 19-26, 2018-Preseason is characterized by high training volumes with short recovery periods β-hydroxy β-methylbutyrate (HMB) has been postulated to assist with recovery. β-hydroxy β-methylbutyrate has been shown to improve strength and body composition among untrained groups; the benefits of HMB among trained populations are unclear because of the methodologies employed. This randomized control trail determined the effects of 11 weeks HMB supplementation on body mass and performance measures in 27 elite rugby players. β-hydroxy β-methylbutyrate group (n = 13), mean ± SD age 20.3 ± 1.2 years, body mass 99.6 ± 9.1 kg; placebo group (n = 14), age 21.9 ± 2.8 years body mass 99.4 ± 13.9 kg for placebo. During the supplementation period, body mass increased with HMB 0.57 ± 2.60 kg but decreased with placebo 1.39 ± 2.02 kg (p = 0.029). There were no significant differences in any of the 4 strength variables (p > 0.05). However, on the yo-yo intermittent recovery test (YoYo IR-1), the placebo group improved 4.0 ± 2.8 levels but HMB decreased 2.0 ± 3.0 levels (p = 0.003). The results of this study suggest that HMB could be beneficial for gaining or maintaining body mass during periods of increased training load. However, it appears that HMB may be detrimental to intermittent running ability in this group although further research is required before firm conclusions can be made. Only 6 participants on HMB managed to complete both YoYo IR-1 tests because of injury, a larger sample size is required to fully investigate this potentially negative effect. Further, the mechanisms behind this decrement in performance cannot be fully explained and requires further biochemical and psychological investigation.

Background: β-Hydroxy-β-methylbutyrate-free acid (HMB-FA) has been ingested prior to exercise to reduce muscle damage, however the effects of HMB-FA supplementation on hormonal, strength and power adaptation are unclear., Methods: Sixteen healthy men were matched and randomized into two groups and performed six-week resistance training while supplementing with either HMB-FA or placebo (3 g per day). The subjects were evaluated for 1 repetition maximum (1RM) bench press and leg press and vertical jump (VJ) prior to and after training intervention. In addition, blood samples were obtained before and after resistance training to evaluate resting growth hormone (GH), insulin like growth factor 1 (IGF-1), testosterone (TEST), cortisol (CORT), and adrenocorticotropic hormone (ACTH) responses. The HMB-FA supplementation group showed greater gains compared with the placebo group in peak power (effect size ES = 0.26 vs. 0.01) and 1RM leg press (ES = 1.52 vs. 0.96). In addition, the HMB-FA supplementation group indicated greater decrements in ACTH and CORT responses to training in comparison to the placebo group ( p < 0.05). Likewise, in GH (ES = 1.41 vs. 0.12) and IGF-1 (ES = 0.83 vs. 0.41), the HMB-FA indicated greater training effects when compared with the placebo group., Conclusions: These findings provide further support for the potential anabolic benefits associated with HMB-FA supplementation., Competing Interests: The authors declare no conflict of interest.

The P2Y 12 receptor expressed in satellite cells of the trigeminal ganglion is thought to contribute to neuropathic pain. The functional interaction between neurons and satellite cells via P2Y 12 receptors and phosphorylated extracellular signal-regulated kinase 1/2 (pERK1/2) underlying neuropathic pain in the tongue was evaluated in this study. Expression of P2Y 12 receptor was enhanced in pERK1/2-immunoreactive cells encircling trigeminal ganglion neurons after lingual nerve crush. The administration to lingual nerve crush rats of a selective P2Y 12 receptor antagonist, MRS2395, attenuated tongue hypersensitivity to mechanical and heat stimulation and suppressed the increase in the relative numbers of calcitonin gene-related peptide (CGRP)-immunoreactive neurons and neurons encircled by pERK1/2-immunoreactive cells. Administration of the P2Y 1,12,13 receptor agonist, 2-(methylthio)adenosine 5'-diphosphate trisodium salt hydrate (2-MeSADP), to naïve rats induced neuropathic pain in the tongue, as in lingual nerve crush rats. Co-administration of 2-MeSADP + MRS2395 to naïve rats did not result in hypersensitivity of the tongue. The relative number of CGRP-immunoreactive neurons increased following this co-administration, but to a lesser degree than observed in 2-MeSADP-administrated naïve rats, and the relative number of neurons encircled by pERK1/2-immunoreactive cells did not change. These results suggest that the interaction between activated satellite cells and CGRP-immunoreactive neurons via P2Y 12 receptors contributes to neuropathic pain in the tongue associated with lingual nerve injury., (© 2017 Eur J Oral Sci.)

Objectives: Normal aging results in cognitive decline and nutritional interventions have been suggested as potential approaches for mitigating these deficits. Here, we used rats to investigate the effects of short- and long-term dietary supplementation with the leucine metabolite β-hydroxy-β-methyl butyrate (HMB) on working memory and cognitive flexibility., Methods: Beginning ∼12 months of age, male and female Long-Evans rats were given twice daily access to sipper tubes containing calcium HMB (450 mg/kg) or vehicle (285 mg/kg calcium lactate) in a sucrose solution (20% w/v). Supplementation continued for 1 or 7 months (middle- and old-age (OA) groups, respectively) before testing began. Working memory was assessed by requiring rats to respond on a previously sampled lever following various delays. Cognitive flexibility was assessed by training rats to earn food according to a visual strategy and then, once acquired, shifting to an egocentric response strategy., Results: Treatment with HMB improved working memory performance in middle-age (MA) males and OA rats of both sexes. In the cognitive flexibility task, there was a significant age-dependent deficit in acquisition of the visual strategy that was not apparent in OA males treated with HMB. Furthermore, HMB ameliorated an apparent deficit in visual strategy acquisition in MA females., Discussion: Together, these findings suggest that daily nutritional supplementation with HMB facilitates learning and improves working memory performance. As such, HMB supplementation may mitigate age-related cognitive deficits and may therefore be an effective tool to combat this undesirable feature of the aging process.

Background: This study investigated the effects of an amino acid mixture containing arginine, glutamine, and β-hydroxy-β-methyl butyrate on secondary healing of ischemic wounds in a rat model (N = 18)., Methods: After the formation of a bipediculated flap on each rat, 2 full-thickness excisional skin wounds (2 × 2 cm) were created on every flap. The rats were then randomized into the control and treatment groups. Every rat received standardized rat food throughout the study. The rats in the treatment group were administered an extra 200 mg/kg of L-arginine, 200 mg/kg of L-glutamine, and 40 mg/kg of β-hydroxy-β-methyl butyrate per day. Wound sizes were measured on days 0, 4, 10, and 14. The rats were sacrificed, and the wounds were excised for biochemical and histologic examination on the 14th day., Results: As compared with the control group, the treatment group's wound sizes were significantly smaller on days 10 and 14 ( P < .001), as was its inflammatory cell accumulation score ( P = .008). There was no significant difference between the 2 groups in collagen accumulation ( P = .340), granulation tissue maturation ( P = .161), angiogenesis ( P = .387), or reepithelialization ( P = .190) and no significant difference between hydroxyproline concentrations in wounds ( P = .287)., Discussion: This amino acid combination seems to have a positive impact on the secondary healing of experimental ischemic wounds when introduced as a supplement to the standard diet, and the reduction in the inflammatory process appears to play a role in this effect.

Beta-hydroxy-beta-methylbutyrate (HMB) is a metabolite of the essential amino acid leucine that has been reported to have anabolic effects on protein metabolism. The aims of this article were to summarize the results of studies of the effects of HMB on skeletal muscle and to examine the evidence for the rationale to use HMB as a nutritional supplement to exert beneficial effects on muscle mass and function in various conditions of health and disease. The data presented here indicate that the beneficial effects of HMB have been well characterized in strength-power and endurance exercise. HMB attenuates exercise-induced muscle damage and enhances muscle hypertrophy and strength, aerobic performance, resistance to fatigue, and regenerative capacity. HMB is particularly effective in untrained individuals who are exposed to strenuous exercise and in trained individuals who are exposed to periods of high physical stress. The low effectiveness of HMB in strength-trained athletes could be due to the suppression of the proteolysis that is induced by the adaptation to training, which may blunt the effects of HMB. Studies performed with older people have demonstrated that HMB can attenuate the development of sarcopenia in elderly subjects and that the optimal effects of HMB on muscle growth and strength occur when it is combined with exercise. Studies performed under in vitro conditions and in various animal models suggest that HMB may be effective in treatment of muscle wasting in various forms of cachexia. However, there are few clinical reports of the effects of HMB on muscle wasting in cachexia; in addition, most of these studies evaluated the therapeutic potential of combinations of various agents. Therefore, it has not been possible to determine whether HMB was effective or if there was a synergistic effect. Although most of the endogenous HMB is produced in the liver, there are no reports regarding the levels and the effects of HMB supplementation in subjects with liver disease. Several studies have suggested that anabolic effects of HMB supplementation on skeletal muscle do not occur in healthy, non-exercising subjects. It is concluded that (i) HMB may be applied to enhance increases in the mass and strength of skeletal muscles in subjects who exercise and in the elderly and (ii) studies examining the effects of HMB administered alone are needed to obtain conclusions regarding the specific effectiveness in attenuating muscle wasting in various muscle-wasting disorders., (© 2017 The Authors. Journal of Cachexia, Sarcopenia and Muscle published by John Wiley & Sons Ltd on behalf of the Society on Sarcopenia, Cachexia and Wasting Disorders.)

In recent years, several pet food recalls have been attributed to Salmonella contamination. In addition to the negative impacts on animal health, Salmonella-contaminated pet foods have been linked to infection in humans. With that in mind, the U.S. Food and Drug Administration has set forth a zero-tolerance policy for Salmonella in pet foods. Typically, pet foods are extruded or processed at high temperatures that are sufficient to reduce pathogenic bacteria. However, the possibility for postextrusion contamination still exists. One potential method to reduce the risk of postextrusion contamination of pet foods with Salmonella is through the addition of a chemical additive coating. The objective of this research was to evaluate the ability of β-hydroxy-β-methylbutyrate (HMB), in either free acid (HMBFA) or calcium salt (CaHMB) form, to reduce postextrusion contamination of dry extruded dog kibble with Salmonella. Three trials were conducted with HMBFA and CaHMB coated onto the kibbles at levels of 0, 0.1, 0.3, 0.5, 0.9, and 1.5% (w/w). The coated kibbles were then inoculated with Salmonella enterica subsp. enterica Enteritidis (ATCC 13076), with enumeration done on days 0, 1, 2, 7, and 14 postinoculation. Subsamples on each day were serially diluted, spread plated to xylose lysine deoxycholate agar, and incubated at 37°C for 24 h. Salmonella colonies were then counted and log CFU per gram was calculated. The 1.5% HMBFA reduced counts by 4.9 ± 0.2 log units on day 1, whereas the positive control only decreased 2.2 ± 0.1 log units (P < 0.0001). The 1.5% CaHMB level decreased counts by 7.1 ± 0.04 log units by day 7 compared with the control decrease of 2.1 ± 0.1 log units (P < 0.0001). All HMBFA and CaHMB treatments resulted in the elimination of detectable Salmonella counts by day 14 (P < 0.0001 versus controls). In conclusion, HMB coating was effective at reducing Salmonella artificially inoculated to dog kibbles in a model of postextrusion contamination.

Beta-hydroxy-beta-methylbutyrate (HMB) is commonly supplemented to maintain muscle in elderly and clinical populations and has potential as a nootropic. Previously, we have shown that in both male and female rats, long-term HMB supplementation prevents age-related dendritic shrinkage within the medial prefrontal cortex (mPFC) and improves cognitive flexibility and working memory performance that are both age- and sex-specific. In this study, we further explore the cognitive effects by assessing visuospatial learning and memory with the Morris water maze. Female rats were ovariectomized at 11months of age to model human menopause. At 12months of age, male and female rats received relatively short- or long-term (1- or 7-month) dietary HMB (450mg/kg/dose) supplementation twice a day prior to testing. Spatial reference learning and memory was assessed across four days in the water maze with four trials daily and a probe trial on the last day. Consistent with previous work, there were age-related deficits in water maze performance in both sexes. However, these deficits were ameliorated in HMB-treated males during training and in both sexes during probe trial performance. Thus, HMB supplementation prevented the age-related decrement in water maze performance, especially in male rats., (Copyright © 2016 Elsevier Inc. All rights reserved.)

Objective: Loss of skeletal muscle function is linked to increased risk for loss of health and independence in older adults. Dietary interventions that can enhance aging muscle function, alone or in combination with exercise, may offer an effective way to reduce these risks. The goal of this study was to evaluate the muscular effects of beta-hydroxy-beta-methylbutyrate (HMB) and beta-alanine (β-Ala) co-supplementation in aged Sprague-Dawley rats with voluntary access to running wheels (RW)., Methods: Aged (20 months) rats were housed with ad libitum access to RW while on a purified diet for 4 weeks, then balanced for RW activity and assigned to either a control or an experimental diet (control + HMB and β-Ala) for the next 4 weeks (n = 10/group). At the end of the study, we assessed muscle size, in situ force and fatigability in the medial gastrocnemius muscles, as well as an array of protein markers related to various age- and activity-responsive signaling pathways., Results: Dietary HMB+β-Ala did not improve muscle force or fatigue resistance, but a trend for increased muscle cross-sectional area (CSA) was observed (P = 0.077). As a result, rats on the experimental diet exhibited reduced muscle quality (force/CSA; P = 0.032). Dietary HMB+β-Ala reduced both the abundance of PGC1-α (P = 0.050) and the ratio of the lipidated to non-lipidated forms of microtubule-associated protein 1 light chain 3 beta (P = 0.004), markers of mitochondrial biogenesis and autophagy, respectively. Some alterations in myostatin signaling also occurred in the dietary HMB+β-Ala group. There was an unexpected difference (P = 0.046) in RW activity, which increased throughout the study in the animals on the control diet, but not in animals on the experimental diet., Conclusions: These data suggest that the short-term addition of dietary HMB+β-Ala to modest physical activity provided little enhancement of muscle function in this model of uncomplicated aging., Competing Interests: S.M.G. is an employee of Abbott Nutrition, a division of Abbott Laboratories, Inc. At the time of study, N.K.E. was also an employee of Abbott Nutrition. Funding for this project was provided by Abbott Nutrition. K.W.M was the recipient of an Ohio University College of Health Science and Professions Graduate Assistantship.

β-Hydroxy β-methylbutyrate (HMB) is a metabolite of the essential amino acid leucine. Recent studies demonstrate a decline in plasma HMB concentrations in humans across the lifespan, and HMB supplementation may be able to preserve muscle mass and strength in older adults. However, the impact of HMB supplementation on hippocampal neurogenesis and cognition remains largely unexplored. The purpose of this study was to simultaneously evaluate the impact of HMB on muscle strength, neurogenesis and cognition in young and aged mice. In addition, we evaluated the influence of HMB on muscle-resident mesenchymal stem/stromal cell (Sca-1 + CD45 - ; mMSC) function to address these cells potential to regulate physiological outcomes. Three month-old (n=20) and 24 month-old (n=18) female C57BL/6 mice were provided with either Ca-HMB or Ca-Lactate in a sucrose solution twice per day for 5.5weeks at a dose of 450mg/kg body weight. Significant decreases in relative peak and mean force, balance, and neurogenesis were observed in aged mice compared to young (age main effects, p≤0.05). Short-term HMB supplementation did not alter activity, balance, neurogenesis, or cognitive function in young or aged mice, yet HMB preserved relative peak force in aged mice. mMSC gene expression was significantly reduced with age, but HMB supplementation was able to recover expression of select growth factors known to stimulate muscle repair (HGF, LIF). Overall, our findings demonstrate that while short-term HMB supplementation does not appear to affect neurogenesis or cognitive function in young or aged mice, HMB may maintain muscle strength in aged mice in a manner dependent on mMSC function., (Copyright © 2016 Elsevier Inc. All rights reserved.)

The aim of this study was to determine the effect of β-hydroxy-β-methylbutyrate acid, on parameters of meat performance in goats as well as on selected parameters of non-specific humoral defense. An experiment was performed on 24 Alpine kids divided into two equal groups: I - control and II - experimental. Over a period of 60 days, the animals were fed an HMB-supplemented diet. The following meat performance parameters were determined: body weight, daily gains, growth rate, the dimensions of musculus longissimus dorsi (m.l.d.) sections and fat thickness over the loin "eye". Selected indicators of non-specific humoral immunity were determined in the blood serum of kids: lysozyme activity, ceruloplasmin activity and gamma globulin content. It was found that the kids administered HMB had a significantly higher body weight on days 30 and 60 of the experiment compared to the control group. The kids in this group also had a significantly more favorable musculature development. Simultaneously, a significant impact of HIMB on the examined immunological indices was found. The significance of differences in relation to the control group was confirmed statistically for lysozyme activity and ceruloplasmin activity on days 30 and 60, while the content of gammaglobulins was confirmed statistically on days 15, 30 and 60 of the study. It was also found that the addition of HMB had a stimulating impact on immunity and growth rate as well as on the development of muscles. It is thus justified to administer HMB to early-weaned kids to enhance their rearing parameters.

Leucine modulates synthetic and degradative pathways in muscle, possibly providing metabolic benefits for both athletes and diseased populations. Leucine has become popular among athletes for improving performance and body composition, however little is known about the metabolic effects of the commonly consumed leucine-derived metabolite β-hydroxy-β-methyl butyrate (HMB). Our work measured the effects of HMB on metabolic protein expression, mitochondrial content and metabolism, as well as lipid content in skeletal muscle cells. Specifically, cultured C2C12 myotubes were treated with either a control or HMB ranging from 6.25 to 25 μM for 24 h and mRNA and/or protein expression, oxygen consumption, glucose uptake, and lipid content were measured. Contrary to leucine's stimulatory effect on metabolism, HMB-treated cells exhibited significantly reduced regulators of lipid oxidation including peroxisome proliferator-activated receptor alpha (PPARα) and PPARβ/δ, as well as downstream target carnitine palmitoyl transferase, without alterations in glucose or palmitate oxidation. Furthermore, HMB significantly inhibited activation of the master regulator of energetics, AMP-activated protein kinase. As a result, HMB-treated cells also displayed reduced total mitochondrial content compared with true control or cells equivocally treated with leucine. Additionally, HMB treatment amplified markers of lipid biosynthesis (PPARγ and fatty acid synthase) as well as consistently promoted elevated total lipid content versus control cells. Collectively, our results demonstrate that HMB did not improve mitochondrial metabolism or content, and may promote elevated cellular lipid content possibly through heightened PPARγ expression. These observations suggest that HMB may be most beneficial for populations interested in stimulating anabolic cellular processes.

Objective: The aim of this research was to check the effect of the prenatally administered β-hydroxy β-methylbutyrate (HMB) on the development of enamel surface of the spiny mice offspring., Design: The spiny mice dams were randomly assigned into three groups: control group (not supplemented with HMB) and two experimental groups in which powdered HMB was given at the daily dosage of 0.2g/kg of body weight (group I) and 0.02g/kg of body weight (group II) during the last period of gestation. Newborn pups were euthanized by CO 2 inhalation. The morphology of incisor teeth was analysed using atomic force microscopy (AFM) in semi-contact mode in the height, magnitude and phase domains. Height images became a basis for determination of surface roughness parameters., Results: Conducted study indicated that maternal HMB administration markedly influences enamel development. Enamel of offspring's teeth in both experimental groups was characterized by significantly smaller values of indices describing surface roughness and profile. HMB supplementation influenced the calculated parameters regardless of the diet type and offspring sex, however higher dose of HMB caused stronger changes in enamel surface's physical properties and could be observed in higher intensity in the male group., Conclusions: HMB administration caused reduction in the irregularities of enamel surface, thereby possibly reducing the probability of bacteria adhesion and caries development. These observations may serve to improve nutrition and supplementation of animals and could be a lead for further research., (Copyright © 2016 Elsevier Ltd. All rights reserved.)

Background: The D1/D2 dopamine agonist apomorphine has poor oral bioavailability, necessitating subcutaneous administration in the treatment of Parkinson's disease (PD). Acute subcutaneous injection is used as rescue therapy from "off" periods, whereas continuous subcutaneous infusion is used to increase "on" periods and to reduce dyskinesia when oral treatment fails. An orally active derivative of apomorphine would avoid the need for parenteral administration. We now describe the effects of the orally active compound R-(-)-11-O-valeryl-N-n-propylnoraporphine (11-OH-NPa valerate) on reversal of motor disability and expression of dyskinesia in 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-treated, l-dopa-primed dyskinetic common marmosets., Methods: Locomotor activity, motor disability, and dyskinesia were assessed in MPTP-treated marmosets following the administration of apomorphine (0.075 mg/kg, subcutaneous and 0.28 to 1.12 mg/kg, oral) and 11-OH-NPa valerate (0.19, 0.38, and 0.75mg/kg, oral)., Results: Subcutaneous administration of apomorphine (0.075 mg/kg) produced a short-lasting reversal of motor disability and the expression of established dyskinesia, but when administered orally (0.28-1.12 mg/kg) it had no effect. In contrast, oral treatment with 11-OH-NPa valerate (0.19 and 0.75 mg/kg) induced a dose-related reversal of motor disability and increased locomotor activity with only mild to moderate dyskinesia. Only at the highest dose (0.75 mg/kg) was marked dyskinesia seen accompanying an extended period of motor disability reversal and increased locomotor activity., Conclusion: Oral administration of 11-OH-NPa valerate produced a rapid reversal of motor disability and, at effective dose levels, had a limited propensity to induce dyskinesia. 11-OH-NPa valerate is the first orally active derivative of apomorphine with potential for use in PD. © 2016 International Parkinson and Movement Disorder Society., (© 2016 International Parkinson and Movement Disorder Society.)

To elucidate if microglial P2Y12 receptor (P2Y12R) mechanisms are involved in the trigeminal spinal subnucleus caudalis (Vc; also known as the medullary dorsal horn) in intraoral cancer pain, we developed a rat model of tongue cancer pain. Squamous cell carcinoma (SCC) cells were inoculated into the tongue of rats; sham control rats received the vehicle instead. Nociceptive behavior was measured as the head-withdrawal reflex threshold (HWRT) to mechanical or heat stimulation applied to the tongue under light anesthesia. On day 14 after the SCC inoculation, activated microglia and P2Y12R expression were examined immunohistochemically in the Vc. The HWRT was also studied in SCC-inoculated rats with successive intra-cisterna magna (i.c.m.) administration of specific P2Y12R antagonist (MRS2395) or intraperitoneal administration of minocycline, a microglial activation inhibitor. Tongue cancer was histologically verified in SCC-inoculated rats, within which the HWRT to mechanical stimulation of the tongue was significantly decreased, as compared with that of vehicle-inoculated rats, although the HWRT to heat stimulation was not. Microglia was strongly activated on day 14, and the administration of MRS2395 or minocycline reversed associated nocifensive behavior and microglial activation in SCC-inoculated rats for 14 d. The activity of Vc wide dynamic range nociceptive neurons was also recorded electrophysiologically in SCC-inoculated and sham rats. Background activity and noxious mechanically evoked responses of wide dynamic range neurons were significantly increased in SCC-inoculated rats versus sham rats, and background activity and mechanically evoked responses were significantly suppressed following i.c.m. administration of MRS2395 in SCC-inoculated rats as compared with sham. The present findings suggest that SCC inoculation that produces tongue cancer results in strong activation of microglia via P2Y12 signaling in the Vc, in association with increased excitability of Vc nociceptive neurons, reflecting central sensitization and resulting in tongue mechanical allodynia., (© International & American Associations for Dental Research 2016.)

Durkalec-Michalski, K and Jeszka, J. The effect of β-hydroxy-β-methylbutyrate on aerobic capacity and body composition in trained athletes. J Strength Cond Res 30(9): 2617-2626, 2016-The aim of this study was to investigate whether supplementation with β-hydroxy-β-methylbutyrate (HMB) affects body composition, aerobic capacity, or intramuscular enzymes activity, as well as in anabolic and/or catabolic hormones and lactate concentrations. A cohort of 58 highly trained males was subjected to 12-week supplementation with HMB (3 × 1 gHMB·d) and a placebo (PLA) in randomized, PLA controlled, double-blind crossover trials, with a 10-day washout period. Body composition and aerobic capacity were recorded, whereas the levels of creatine kinase, lactate dehydrogenase, testosterone, cortisol, and lactate, as well as the T/C ratio, in blood samples were measured. After HMB supplementation, fat-free mass increased (+0.2 kgHMB vs. -1.0 kgPLA, p = 0.021), with a simultaneous reduction of fat mass (-0.8 kgHMB vs. +0.8 kgPLA, p < 0.001). In turn, after HMB supplementation, in comparison to PLA, maximal oxygen uptake (V[Combining Dot Above][Combining Dot Above]O2max: +0.102 L·minHMB vs. -0.063 L·minPLA, p = 0.013), time to reach ventilatory threshold (VT) (TVT: +1.0 minHMB vs. -0.4 minPLA, p < 0.0001), threshold load at VT (WVT: +20 WHMB vs. -7 WPLA, p = 0.001), and the threshold heart rate at VT (HRVT: +8 b·minHMB vs. -1 b·minPLA, p < 0.0001) increased significantly. Analysis of the tested biochemical markers shows significant differences only in relation to the initial concentration. In HMB group, testosterone levels increased (p = 0.047) and in both groups (HMB: p = 0.008; PLA: p = 0.008) higher cortisol levels were observed. The results indicate that supplying HMB promotes advantageous changes in body composition and stimulates an increase in aerobic capacity, although seeming not to significantly affect the levels of the analyzed blood markers.

Synaptic inhibition in the olfactory bulb (OB), the first relay station of olfactory information, is believed to be important for odour discrimination. We interfered with GABAergic inhibition of mitral and tufted cells (M/T cells), the principal neurons of the OB, by disrupting their potassium-chloride cotransporter 2 (Kcc2). Roughly, 70% of mice died around 3 weeks, but surviving mice appeared normal. In these mice, the resulting increase in the intracellular Cl(-) concentration nearly abolished GABA-induced hyperpolarization of mitral cells (MCs) and unexpectedly increased the number of perisomatic synapses on MCs. In vivo analysis of odorant-induced OB electrical activity revealed increased M/T cell firing rate, altered phasing of action potentials in the breath cycle and disrupted separation of odour-induced M/T cell activity patterns. Mice also demonstrated a severely impaired ability to discriminate chemically similar odorants or odorant mixtures. Our work suggests that precisely tuned GABAergic inhibition onto M/T cells is crucial for M/T cell spike pattern separation needed to distinguish closely similar odours.

The purpose of this experiment was to determine if supplying butyrate to the postruminal gastrointestinal tract of growing lambs alters blood flow and nutrient flux across the portal-drained viscera (PDV) and hepatic tissues. Polled Dorset wether lambs ( = 10; initial BW = 55 ± 3.3 kg) had catheters surgically implanted into the portal vein, a branch of the hepatic vein, a mesenteric vein, and the abdominal aorta. A cannula was placed in the abomasum to deliver the treatment. Lambs were fed a pelleted ration once daily consisting of 69.7% dehydrated alfalfa, 30.0% ground corn, and 0.3% salt at 1.3 × NE requirement. The experimental design was a crossover balanced in time, so that each lamb received both treatments. Treatments consisted of either a pulse dose infusion of butyrate (buffered solution) to supply butyrate (10 mg/kg BW) or a buffered saline solution (1 mL/kg BW) once daily at the time of feeding. On d 14 of the treatment period, nutrient fluxes were measured using para-aminohippuric acid as a blood flow marker. Blood samples were collected from the aorta, portal vein, and hepatic vein every hour for 9 h beginning at 30 min prior to treatment/feeding. There was a tendency for a treatment × time interaction ( = 0.05) for portal vein blood flow, indicating that blood flow began to decrease earlier postprandial in lambs receiving butyrate. The butyrate treatment tended to increase the uptake of O ( = 0.07) and increased the uptake of glucose ( = 0.002), glutamate ( = 0.04), and glutamine ( = 0.02) by the PDV. There was a treatment × time interaction ( < 0.01) for flux of acetate, propionate, butyrate, isobutyrate, and valerate across the PDV. The interaction was mainly due to an earlier postprandial peak and associated decrease in the flux rate of the VFA. The alteration in timing of the postprandial peak of VFA flux was also observed in hepatic fluxes of VFA. It appears that supplying butyrate to the postruminal tissues through an abomasal cannula increases glucose, glutamate, and glutamine metabolism by the PDV.

A new pyrone named 6-isovaleryl-4-methoxy-pyran-2-one (1), along with three known pyrone compounds, rubrofusarin B (2), asperpyrones A (3) and campyrone A (4), was isolated from fermentation of Aspergillus tubingensis in Lycium ruthenicum. Their structures were confirmed by spectroscopic techniques, such as IR, NMR and HRESI-MS. Compound 2 indicated strong inhibitory activity against Escherichia coli, with MIC value of 1.95 μg/mL.

Lowery, RP, Joy, JM, Rathmacher, JA, Baier, SM, Fuller, JC Jr, Shelley, MC II, Jäger, R, Purpura, M, Wilson, SMC, and Wilson, JM. Interaction of beta-hydroxy-beta-methylbutyrate free acid and adenosine triphosphate on muscle mass, strength, and power in resistance trained individuals. J Strength Cond Res 30(7): 1843-1854, 2016-Adenosine-5'-triphosphate (ATP) supplementation helps maintain performance under high fatiguing contractions and with greater fatigue recovery demands also increase. Current evidence suggests that the free acid form of β-hydroxy-β-methylbutyrate (HMB-FA) acts by speeding regenerative capacity of skeletal muscle after high-intensity or prolonged exercise. Therefore, we investigated the effects of 12 weeks of HMB-FA (3 g) and ATP (400 mg) administration on lean body mass (LBM), strength, and power in trained individuals. A 3-phase double-blind, placebo-, and diet-controlled study was conducted. Phases consisted of an 8-week periodized resistance training program (phase 1), followed by a 2-week overreaching cycle (phase 2), and a 2-week taper (phase 3). Lean body mass was increased by a combination of HMB-FA/ATP by 12.7% (p < 0.001). In a similar fashion, strength gains after training were increased in HMB-FA/ATP-supplemented subjects by 23.5% (p < 0.001). Vertical jump and Wingate power were increased in the HMB-FA/ATP-supplemented group compared with the placebo-supplemented group, and the 12-week increases were 21.5 and 23.7%, respectively. During the overreaching cycle, strength and power declined in the placebo group (4.3-5.7%), whereas supplementation with HMB-FA/ATP resulted in continued strength gains (1.3%). In conclusion, HMB-FA and ATP in combination with resistance exercise training enhanced LBM, power, and strength. In addition, HMB-FA plus ATP blunted the typical response to overreaching, resulting in a further increase in strength during that period. It seems that the combination of HMB-FA/ATP could benefit those who continuously train at high levels such as elite athletes or military personnel.

Beta-hydroxy-beta-methylbutyrate (HMB), a supplement commonly used to maintain muscle in elderly and clinical populations, has been unexplored in the aging brain. In both healthy aging humans and rat models, there are cognitive deficits associated with age-related dendritic shrinkage within the prefrontal cortex. The present study explores the effects of relatively short- and long-term (7 and 31 weeks) oral HMB supplementation starting at 12 months of age in male and female rats on the dendritic tree of layer 5 pyramidal neurons in the medial prefrontal cortex. Since female rats continue to secrete ovarian hormones after reaching reproductive senescence, middle-aged female rats were ovariectomized to model humans. As expected, there were fewer spines and a retraction of dendritic material in the apical and basilar trees in old age controls of both sexes compared with their middle-aged counterparts. However, these losses did not occur in the HMB-treated rats in either dendrites or the total number of dendritic spines. Thus, HMB forestalled the effects of aging on the dendritic tree of this population of neurons., (Copyright © 2016 Elsevier Inc. All rights reserved.)

Position Statement: The International Society of Sports Nutrition (ISSN) bases the following position stand on an analysis of the literature regarding the effects of β-Hydroxy-β-Methylbutyrate (HMB). The following 12 points have been approved by the Research Committee of the Society: 1. HMB is a metabolite of the amino acid leucine that is naturally produced in both humans and other animals. Two forms of HMB have been studied: Calcium HMB (HMB-Ca) and a free acid form of HMB (HMB-FA). HMB-FA appears to lead to increased appearance of HMB in the bloodstream when compared to HMB-Ca, though recent results are mixed. 2. The available safety/toxicity data suggest that chronic HMB-Ca and HMB-FA consumption are safe for oral HMB supplementation in humans up to at least one year. 3. There are no negative effects of HMB-Ca and HMB-FA on glucose tolerance and insulin sensitivity in humans. There may be improvements in glucose metabolism in younger adults. 4. The primary mode of action of HMB appears to be through its dual mechanism to enhance muscle protein synthesis and suppress muscle protein breakdown. HMB's activation of mTORC1 is independent of the leucine-sensing pathway (Sestrin2-GATOR2 complex). 5. HMB may help reduce muscle damage and promote muscle recovery, which can promote muscle growth/repair. HMB may also have anti-inflammatory effects, which could contribute to reducing muscle damage and soreness. 6. HMB consumption in close proximity to an exercise bout may be beneficial to increase muscle protein synthesis and attenuate the inflammatory response. HMB can provide a beneficial physiological effect when consumed both acutely and chronically in humans. 7. Daily HMB supplementation (38 mg/kg body weight) in combination with exercise training may improve body composition through increasing lean mass and/or decreasing fat mass with benefits in participants across age, sex, and training status. The most pronounced of these improvements in body composition with HMB have been observed in studies with robust resistance training programs and dietary control. 8. HMB may improve strength and power in untrained individuals, but its performance benefits in trained athletes are mixed and increase with an increase in study duration (>6 weeks). HMB's beneficial effects on athletic performance are thought to be driven by improved recovery. 9. HMB supplementation appears to potentially have a positive impact on aerobic performance, especially in trained athletes. The mechanisms of the effects are unknown. 10. HMB supplementation may be important in a non-exercising sedentary and aging population to improve muscle strength, functionality, and muscle quality. The effects of HMB supplementation with exercise are varied, but the combination may have a beneficial effect on the treatment of age-associated sarcopenia under select conditions. 11. HMB may be effective in countering muscle disuse atrophy during periods of inactivity due to illness or injury. The modulation of mitochondrial dynamics and lipid metabolism by HMB may be a potential mechanism for preventing disuse atrophy and aiding rehabilitation beyond HMB's effects on rates of muscle protein synthesis and degradation. 12. The efficacy of HMB in combination with certain nutrients may be enhanced under select conditions.

This study evaluated the effects of dietary β-hydroxy-β-methylbutyrate (HMB) combined with β-alanine (β-Ala) in sedentary, aged male rats. It has been suggested that dietary HMB or β-Ala supplementation may mitigate age-related declines in muscle strength and fatigue resistance. A total of 20 aged Sprague-Dawley rats were studied. At age 20 months, 10 rats were administered a control, purified diet and 10 rats were administered a purified diet supplemented with both HMB and β-Ala (HMB+β-Ala) for 8 weeks (approximately equivalent to 3 and 2.4 g per day human dose). We measured medial gastrocnemius (MG) size, force, fatigability, and myosin composition. We also evaluated an array of protein markers related to muscle mitochondria, protein synthesis and breakdown, and autophagy. HMB+β-Ala had no significant effects on body weight, MG mass, force or fatigability, myosin composition, or muscle quality. Compared with control rats, those fed HMB+β-Ala exhibited a reduced (41%, P = 0.039) expression of muscle RING-finger protein 1 (MURF1), a common marker of protein degradation. Muscle from rats fed HMB+β-Ala also exhibited a 45% reduction (P = 0.023) in p70s6K phosphorylation following fatiguing stimulation. These data suggest that HMB+β-Ala at the dose studied may reduce muscle protein breakdown by reducing MURF1 expression, but has minimal effects on muscle function in this model of uncomplicated aging. They do not, however, rule out potential benefits of HMB+β-Ala co-supplementation at other doses or durations of supplementation in combination with exercise or in situations where extreme muscle protein breakdown and loss of mass occur (e.g., bedrest, cachexia, failure-to-thrive).