The effects of dietary protein and amino acids on skeletal metabolism

Impact of fermentation by Saccharomyces Cerevisiae on the macronutrient and in vitro digestion characteristics of Chinese noodles

This study examined the impact of live bread yeast (Saccharomyces cerevisiae) on the nutritional characteristics of Asian dried noodles. Micronutrient analysis of fermented noodles revealed a 6.9% increase in the overall amino acid content, a 37.1% increase in the vitamin B content and a 63.0% decrease in the phytic acid level. Molecular weight analysis of starch and protein contents revealed moderate decrease in the fermented noodles. The in vitro digestion of fermented noodles showed a slightly faster initial acidification, four-fold decrease in the initial shear viscosity (from 8.85 to 1.94 Pa·s). The initial large food particle count (>2 mm diameter) was 19.5% lower in the fermented noodles. The fermented noodles contained slightly higher free sugar content (73.5 mg g-1 noodle) during the gastric digestion phase. The overall nutrition and digestion results indicate nutritional improvement and digestion-easing attributes in the fermented noodles.

The association between bone density of lumbar spines and different daily protein intake in different renal function

BACKGROUND

Low protein intake (LPI) has been suggested as a treatment for chronic kidney disease (CKD). However, protein intake is essential for bone health.

METHODS

We studied the database of the National Health and Nutrition Examination Survey, 2005-2010. Basic variables, metabolic diseases, and bone density of different femoral areas were stratified into four subgroups according to different protein intake (DPI) (that is, <0.8, 0.8-1.0, 1.0-1.2, and >1.2 g/kg/day).

RESULTS

Significant differences were found among all lumbar area bone mineral density (BMD) and T-scores (p < 0.0001). There was an apparent trend between a decreasing BMD in the CKD groups with increasing DPI in all single lumbar spines (L1, L2, L3, and L4) and all L spines (L1-L4). Compared with DPI (0.8-1.0 g/day/kg), higher risks of osteoporosis were noticed in the subgroup of >1.2 g/day/kg over L2 (relative risk (RR)=1.326, 95% confidence interval (CI)=1.062-1.656), subgroup >1.2 g/day/kg over L3 (RR = 1.31, 95%CI = 1.057-1.622), subgroup <0.8 g/day/kg over L4 (RR = 1.276, 95%CI = 1.015-1.605), subgroup <0.8 g/day/kg over all L spines (RR = 11.275, 95%CI = 1.051-1.548), and subgroup >1.2 g/day/kg over all L spines (RR = 0.333, 95%CI = 1.098-1.618). However, a higher risk of osteoporosis was observed only in the non-CKD group. There was an apparent trend of higher DPI coexisting with lower BMD and T scores in patients with CKD. For osteoporosis (reference:0.8-1.0 g/day/kg), lower (<0.8 g/day/kg) or higher DPI (>1.2 g/day/kg) was associated with higher risks in the non-CKD group, but not in the CKD group.

CONCLUSIONS

In the CKD group, LPI for renal protection was safe without threatening L spine bone density and without causing a higher risk of osteoporosis.

Krüppel-like factors family in health and disease

Krüppel-like factors (KLFs) are a family of basic transcription factors with three conserved Cys2/His2 zinc finger domains located in their C-terminal regions. It is acknowledged that KLFs exert complicated effects on cell proliferation, differentiation, survival, and responses to stimuli. Dysregulation of KLFs is associated with a range of diseases including cardiovascular disorders, metabolic diseases, autoimmune conditions, cancer, and neurodegenerative diseases. Their multidimensional roles in modulating critical pathways underscore the significance in both physiological and pathological contexts. Recent research also emphasizes their crucial involvement and complex interplay in the skeletal system. Despite the substantial progress in understanding KLFs and their roles in various cellular processes, several research gaps remain. Here, we elucidated the multifaceted capabilities of KLFs on body health and diseases via various compliable signaling pathways. The associations between KLFs and cellular energy metabolism and epigenetic modification during bone reconstruction have also been summarized. This review helps us better understand the coupling effects and their pivotal functions in multiple systems and detailed mechanisms of bone remodeling and develop potential therapeutic strategies for the clinical treatment of pathological diseases by targeting the KLF family.

Calcium, Phosphorus, and Vitamin D Levels in a Series of Cystic Fibrosis Patients: A Cross-Sectional Study

Cystic fibrosis (CF) is a monogenic disease with different types of mutations that mainly affect the respiratory-digestive system. Calcium (Ca), phosphorus (P), and vitamin D (Vit-D) are essential nutrients for maintaining adequate growth and development, as well as key components in crucial metabolic pathways. Proper diagnosis, treatment, and response are decisive components of precision medicine. Therefore, we conducted a cross-sectional study to evaluate Ca, P, and Vit-D levels along with health and nutritional indicators, regarding their non-skeletal functions, in a series of CF patients. Anthropometric and clinical evaluation, biochemical analysis, dietary survey, and respiratory and pancreatic status were performed. Even though the results showed that all patients had normal dietary and serum Ca levels, 47% of patients had deficient Vit-D intake, 53% of patients had hypovitaminosis D, 35% had insufficient Vit-D levels, 18% had hypophosphatemia, 76% had elevated alkaline phosphate levels, 29% had hypercalciuria, and 65% had hyperphosphaturia. There were no significant differences between homozygous and compound heterozygous patients. Ca, P, and Vit-D levels were associated with body mass index; body composition; physical activity; diet; growth hormones; and the immune, liver, and kidney systems. We suggest a periodically evaluation of Ca and P losses.

Physicochemical Properties of Mixed Gelatin Gels with Soy and Whey Proteins

The physicochemical properties of the mixed gelatin gels with soy and whey proteins were investigated to develop the gel base with a soft texture and abundant essential amino acids for the elderly. Gelatin-only gel (control) was prepared at 6% (w/v), and mixed gelatin gels were formulated by replacing gelatin with soy protein isolate and whey protein concentrate at different mixing ratios [gelatin (G):soy protein isolate (S):whey protein concentrate (W)]. Results showed that replacing gelatin with the globular proteins in gelatin gels increased the pH value and processing yield (p < 0.05). Moreover, the mixed gelatin gels, particularly the G2:S1:W3 treatment, showed significantly higher essential amino acids than the gelatin-only control. The partial replacement of gelatin with the globular proteins could decrease the hardness of gelatin gel (p < 0.05), but there was no difference in hardness between the G2:G3:W1, G2:S2:W2, and G2:S1:W3 treatments (p > 0.05). The results of protein pattern, x-ray diffraction, and microstructure had no clear evidence for specific protein-protein interaction in the mixed gelatin gels. Therefore, this study indicates that mixed gelatin gels with the globular proteins at specific mixing ratios could be a practical approach to providing a soft texture and high-level essential amino acids to the elderly.

Effects of partial replacement of red and processed meat with non-soya legumes on bone and mineral metabolism and amino acid intakes in BeanMan randomised clinical trial

The transition towards more plant-based diets may pose risks for bone health such as low vitamin D and Ca intakes. Findings for the contribution of animal and plant proteins and their amino acids (AA) to bone health are contradictory. This 6-week clinical trial aimed to investigate whether partial replacement of red and processed meat (RPM) with non-soya legumes affects AA intakes and bone turnover and mineral metabolism in 102 healthy 20-65-year-old men. Participants were randomly assigned to diet groups controlled for RPM and legume intake (designed total protein intake (TPI) 18 E%): the meat group consumed 760 g RPM per week (25 % TPI) and the legume group consumed non-soya legume-based products (20 % TPI) and 200 g RPM per week, the upper limit of the Planetary Health Diet (5 % TPI). No differences in bone (bone-specific alkaline phosphatase; tartrate-resistant acid phosphatase 5b) or mineral metabolism (25-hydroxyvitamin D; parathyroid hormone; fibroblast growth factor 23; phosphate and Ca) markers or Ca and vitamin D intakes were observed between the groups (P > 0·05). Methionine and histidine intakes were higher in the meat group (P ≤ 0·042), whereas the legume group had higher intakes of arginine, asparagine and phenylalanine (P ≤ 0·013). Mean essential AA intakes in both groups met the requirements. Increasing the proportion of non-soya legumes by reducing the amount of RPM in the diet for 6 weeks did not compromise bone turnover and provided on average adequate amounts of AA in healthy men, indicating that this ecologically sustainable dietary change is safe and relatively easy to implement.

Serum phospholipid fatty acids are associated with bone mass in healthy 4-years-old children

BACKGROUND

Fatty acids are involved in bone development but knowledge in children is limited. The aim of this study was to investigate bone mass and mineral density in healthy preschool children in relation to fatty acids.

MATERIAL AND METHODS

In 111 healthy 4-yrs-old children (20 % overweight) bone was analysed by dual X-ray absorptiometry and serum phospholipid fatty acid by gas chromatography. Fat intake was calculated from 7 days self-reported dietary records and food frequency questionnaire.

RESULTS

Total bone mass content (BMC) and mineral density (BMD) differed by sex in normal weight, but not in overweight children showing generally higher bone mass density than children with normal weight. Linoleic acid intake was strongly correlated to BMC and femoral BMD in normal weight children. Serum concentration of docosahexaenoic acid correlated positively to BMD in all children (p = 0.01), but linoleic and arachidonic acids, and monounsaturated fatty acids showed diverging associations with bone in normal weight and overweight children.

CONCLUSION

Serum phospholipid DHA was associated with bone density. Other fatty acids associations to bone sites differed in overweight children, analogue to the pattern in healthy 8-yrs-old.The finding need to be confirmed longitudinally and in a larger group of overweight individuals.

Distinct Metabolites in Osteopenia and Osteoporosis: A Systematic Review and Meta-Analysis

Multiple studies have indicated that distinct metabolites are involved in the occurrence and development of osteopenia (ON) and osteoporosis (OP); however, these metabolites in OP and ON have not yet been classified and standardized. This systematic review and meta-analysis included 21 articles aiming to investigate the distinct metabolites in patients with ON and OP. The quality of the included articles was generally high; seventeen studies had >7 stars, and the remaining four received 6 stars. This systematic review showed that three metabolites (phosphatidylcholine (PC) (lipid metabolites), galactose (carbohydrate metabolites), and succinic acid (other metabolites)) increased, four (glycylglycine (gly-gly), cystine (amino acids), sphingomyelin (SM) (lipid metabolites) and glucose (carbohydrate metabolites)) decreased, and five (glutamine, hydroxyproline, taurine (amino acids), lysophosphatidylcholine (LPC) (lipid metabolites), and lactate (other metabolites)) had conflicting directions in OP/ON. The results of the meta-analysis show that gly-gly (MD = -0.77, 95%CI -1.43 to -0.11, p = 0.02) and cystine (MD = -5.52, 95%CI -7.35 to -3.68, p < 0.00001) decreased in the OP group compared with the healthy control group. Moreover, LPC (MD = 1.48, 95%CI 0.11 to 2.86, p = 0.03) increased in the OP group compared with the healthy control group. These results indicate that distinct metabolites were associated with ON and OP, which could be considered a predictor for OP.

The skeletal safety of milk-derived proteins: A meta-analysis of randomized controlled trials

PURPOSE

There has been a persistent claim that dairy products contain calcium-leaching proteins, although the soundness of such a claim has been challenged. A meta-analysis of randomized controlled trials (RCTs) on the effects of milk-derived protein supplementation on bone health indices in adults was performed to reconcile the controversy surrounding the potential skeletal safety concerns of proteins of dairy origin.

METHODS

The PubMed and Web of Science databases were searched for relevant RCTs. A random-effects model was used to generate pooled effect sizes and 95% confidence intervals.

RESULTS

Milk-derived protein supplementation did not significantly affect whole-body BMD (n = 7 RCTs) and BMD at the lumbar spine (n = 10), hip (n = 8), femoral neck (n = 9), trochanter (n = 5), intertrochanter (n = 2), and ultradistal radius (n = 2). The concentrations of bone formation markers (bone-specific alkaline phosphatase [n = 11], osteocalcin [n = 6], procollagen type 1 amino-terminal propeptide [n = 5]), bone resorption markers (N-terminal telopeptide of type 1 collagen [n = 7], C-terminal telopeptide of type 1 collagen [n = 7], deoxypyridinoline [n = 4]), and parathyroid hormone (n = 7) were not significantly affected. However, increased insulin-like growth factor-1 (IGF-1) concentrations (n = 13) were observed. Reduced IGF-1 concentrations were observed when soy protein was used as a comparator, and increased IGF-1 concentrations were observed when carbohydrate was used.

CONCLUSION

Our findings do not support the claim that proteins of dairy origin are detrimental to bone health.

Plasma Levels of Branched Chain Amino Acids, Incident Hip Fractures, and Bone Mineral Density of the Hip and Spine

OBJECTIVE

Branched chain amino acids (BCAA) are building blocks for protein, an essential component of bone. However, the association of plasma levels of BCAA with fractures in populations outside of Hong Kong or with hip fractures in particular is not known. The purpose of these analyses was to determine the relationship of BCAA including valine, leucine, and isoleucine and total BCAA (SD of the sum of Z-scores for each BCAA) with incident hip fractures and bone mineral density (BMD) of the hip and lumbar spine in older African American and Caucasian men and women in the Cardiovascular Health Study.

DESIGN

Longitudinal analyses of association of plasma levels of BCAA with incident hip fractures and cross-sectional BMD of the hip and lumbar spine from the Cardiovascular Health Study.

SETTING

Community.

PARTICIPANTS

A total of 1850 men (38% of cohort) and women; mean age 73 years.

MAIN OUTCOME MEASURES

Incident hip fractures and cross-sectional BMD of the total hip, femoral neck, and lumbar spine.

RESULTS

In fully adjusted models, over 12 years of follow-up, we observed no significant association between incident hip fracture and plasma values of valine, leucine, isoleucine, or total BCAA per 1 SD higher of each BCAA. Plasma values of leucine but not valine, isoleucine, or total BCAA, were positively and significantly associated with BMD of the total hip (P = .03) and femoral neck (P = .02), but not the lumbar spine (P = .07).

CONCLUSIONS

Plasma levels of the BCAA leucine may be associated with higher BMD in older men and women. However, given the lack of significant association with hip fracture risk, further information is needed to determine whether BCAAs would be novel targets for osteoporosis therapies.

Low Circulating Valine Associate With High Risk of Hip Fractures

CONTEXT

Hip fractures constitute a major health concern. An adequate supply of amino acids is crucial to ensure optimal acquisition and remodeling of bone. Circulating amino acid levels have been proposed as markers of bone mineral density, but data on their ability to predict incident fractures are scarce.

OBJECTIVES

To investigate the associations between circulating amino acids and incident fractures.

METHODS

We used UK Biobank (n = 111 257; 901 hip fracture cases) as a discovery cohort and the Umeå Fracture and Osteoporosis (UFO) hip fracture study (hip fracture cases n = 2225; controls n = 2225) for replication. Associations with bone microstructure parameters were tested in a subsample of Osteoporotic Fractures in Men Sweden (n = 449).

RESULTS

Circulating valine was robustly associated with hip fractures in the UK Biobank (HR per SD increase 0.79, 95% CI 0.73-0.84), and this finding was replicated in the UFO study (combined meta-analysis including 3126 incident hip fracture cases, odds ratio per SD increase 0.84, 95% CI 0.80-0.88). Detailed bone microstructure analyses showed that high circulating valine was associated with high cortical bone area and trabecular thickness.

CONCLUSION

Low circulating valine is a robust predictor of incident hip fractures. We propose that circulating valine may add information for hip fracture prediction. Future studies are warranted to determine whether low valine is causally associated with hip fractures.

The muscle nutritional components analysis of golden pompano (Trachinotus blochii) in different mariculture area, growth stages, and genders

Golden pompano (Trachinotus blochii) is an economically important fish which exhibits sexual size dimorphism and is widely cultivated in the southern seas of China. To evaluate the nutritional composition of T. blochii of different mariculture areas, growth stages, and genders, the moisture, ash, amino acids, and fatty acids in the muscle were measured using national standard biochemical assay. The analysis found 16 kinds of amino acids in the muscle of T. blochii. The EAA contents of fish from Guangdong (GD) and Guangxi (GX) were significantly lower than those of Hainan (HN) and Fujian (FJ) (p < 0.05). The unsaturated fatty acids were higher in T. blochii cultured in HN and FJ (p < 0.05). Within the same sea area, the contents of TAA, EAA, DAA, and PUFA increased with growth in T. blochii, but the differences were not significant (p > 0.05). EAA/TAA and EAA/NEAA conformed to the ideal FAO/WHO model. The AAS, CS, and EAAI scores of amino acids within groups gradually increased with growth. The TAA, EAA and PUFA contents in females were higher than in males (p > 0.05). The slightly higher amounts of amino acids and fatty acids in female T. blochii indicated females had higher nutritional value. In conclusion, the HN and FJ groups, the later growth stages, and the female T. blochii had generally higher nutritional values than their respective counterparts. These results provide fundamental data supporting all-female T. blochii breeding and culture, and optimized marketing body size.

Dietary Intake and Circulating Amino Acid Concentrations in Relation with Bone Metabolism Markers in Children Following Vegetarian and Omnivorous Diets

Scientific studies reported that most vegetarians meet the total protein requirements; however, little is known about their amino acid intakes. We aimed to assess dietary intake and serum amino acid levels in relation to bone metabolism markers in prepubertal children on vegetarian and traditional diets. Data from 51 vegetarian and 25 omnivorous children aged 4–9 years were analyzed. Dietary intake of macro- and micronutrients were assessed using the nutritional program Dieta 5®. Serum amino acid analysis was performed using high-pressure liquid chromatography technique, 25-hydroxyvitamin D and parathormone–electrochemiluminescent immunoassay, and bone metabolism markers, albumin, and prealbumin levels using enzyme-linked immunosorbent assay. Vegetarian children had a significantly lower intake of protein and amino acids with median differences of about 30–50% compared to omnivores. Concentrations of four amino acids (valine, lysine, leucine, isoleucine) in serum varied significantly by diet groups and were lower by 10–15% in vegetarians than meat-eaters. Vegetarian children also had lower (p < 0.001) serum albumin levels compared to omnivores. Among bone markers, they had higher (p < 0.05) levels of C-terminal telopeptide of collagen type I (CTX-I) than omnivores. Correlation patterns between amino acids and bone metabolism markers differed in the vegetarian and omnivore groups. Out of bone markers, especially osteoprotegerin was positively correlated with several amino acids, such as tryptophan, alanine, aspartate, glutamine, and serine, and ornithine in vegetarians. Vegetarian children consumed apparently sufficient but lower protein and amino acids compared to omnivores. In circulation these differences were less marked than in the diet. Significantly lower amino acid intake and serum levels of valine, lysine, leucine, and isoleucine as well as the observed correlations between serum amino acids and biochemical bone marker levels indicated the relations between diet, protein quality, and bone metabolism.

Effects of dietary crude protein levels in the concentrate supplement after grazing on rumen microbiota and metabolites by using metagenomics and metabolomics in Jersey-yak

Introduction

The crude protein level in the diet will affect the fermentation parameters, microflora, and metabolites in the rumen of ruminants. It is of great significance to study the effect of crude protein levels in supplementary diet on microbial community and metabolites for improving animal growth performance. At present, the effects of crude protein level in supplementary diet on rumen fermentation parameters, microbial community, and metabolites of Jersey-Yak (JY) are still unclear.

Methods

The purpose of this experiment was to study the appropriate crude protein level in the diet of JY. The rumen fermentation indexes (volatile fatty acids and pH) were determined by supplementary diets with crude protein levels of 15.16 and 17.90%, respectively, and the microbial community and metabolites of JYs were analyzed by non-target metabonomics and metagenome sequencing technology, and the changes of rumen fermentation parameters, microbial flora, and metabolites in the three groups and their interactions were studied.

Results and Discussion

The crude protein level in the supplementary diet had significant effects on pH, valeric acid, and the ratio of acetic acid to propionic acid (p < 0.05). The protein level had no significant effect on the dominant microflora at the phylum level (p > 0.05), and all three groups were Bacteroides and Firmicutes. The results of metabolite analysis showed that the crude protein level of supplementary diet significantly affected the metabolic pathways such as Bile secretion and styrene degradation (p < 0.05), and there were different metabolites between the LP group and HP group, and these different metabolites were related to the dominant microbial to some extent. To sum up, in this experiment, the effects of crude protein level in supplementary diet on rumen microorganisms and metabolites of JY and their relationship were studied, which provided the theoretical basis for formulating a more scientific and reasonable supplementary diet in the future.

Modifiable risk factors for bone health & fragility fractures

Osteoporosis is an ageing disorder characterised by poor microstructural architecture of the bone and an increase in the risk of fragility fractures, which often leads to hospitalisation and eventually a loss of mobility and independence. By 2050, it is estimated that more than 30 million people in Europe will be affected by bone diseases, and European hospitalisation alone can approximately cost up to 3.5 billion euros each year [1]. Although inherited variation in bone mineral density (BMD) is pre-determined by up to 85% [2], there is a window of opportunity to optimise BMD and reduce fracture risk through key modifiable lifestyle factors during the life course. An optimal diet rich in micronutrients, such as calcium, vitamin D, and potassium, has long been considered an important modifiable component of bone health, which is attributed to their direct roles within bone metabolism. Recently, there has been emerging evidence to suggest that protein and even an adequate intake of fruit and vegetables may also play an important role in improving BMD [3,4]. Maintaining a physically active lifestyle is not only protective from non-communicable diseases such as cardiovascular disease but it also has been shown to lessen the risk of fractures later in life, thereby making it an imperative modifiable factor for bone health, particularly as it also supports peak bone mass attainment during childhood/adolescence and can facilitate the maintenance of bone mass throughout adulthood [5]. Other key lifestyle factors that could be potentially modified to reduce the risk of osteoporosis or osteoporotic fractures later in life include smoking status, alcohol intake, and body composition [6]. Therefore, the principle aim of this review is to highlight the recent evidence pertaining to modifiable lifestyle factors that contribute to optimal bone health and the prevention of fragility fractures in later life.

Clinical implications of low estimated protein intake in patients with heart failure

BACKGROUND

A higher protein intake has been associated with a higher muscle mass and lower mortality rates in the general population, but data about protein intake and survival in patients with heart failure (HF) are lacking.

METHODS

We studied the prevalence, predictors, and clinical outcome of estimated protein intake in 2516 patients from the BIOlogy Study to TAilored Treatment in Chronic Heart Failure (BIOSTAT-CHF) index cohort. Protein intake was calculated in spot urine samples using a validated formula [13.9 + 0.907 * body mass index (BMI) (kg/m² ) + 0.0305 * urinary urea nitrogen level (mg/dL)]. Association with mortality was assessed using multivariable Cox regression models. All findings were validated in an independent cohort.

RESULTS

We included 2282 HF patients (mean age 68 ± 12 years and 27% female). Lower estimated protein intake in HF patients was associated with a lower BMI, but with more signs of congestion. Mortality rate in the lowest quartile was 32%, compared with 18% in the highest quartile (P < 0.001). In a multivariable model, lower estimated protein intake was associated with a higher risk of death compared with the highest quartile [hazard ratio (HR) 1.50; 95% confidence interval (CI) 1.03-2.18, P = 0.036 for the lowest quartile and HR 1.46; 95% CI 1.00-2.18, P = 0.049 for the second quartile].

CONCLUSIONS

An estimated lower protein intake was associated with a lower BMI, but signs of congestion were more prevalent. A lower estimated protein intake was independently associated with a higher mortality risk.

Dietary branched-chain amino acids modulate the dynamics of calcium absorption and reabsorption in protein-restricted pigs

Background

Very low-protein (VLP) diets negatively impact calcium (Ca) metabolism and absorption. The objective of this study was to investigate the effect of supplemental branched-chain amino acids (BCAA) and limiting amino acids (LAA) on Ca digestibility, absorption and reabsorption in pigs fed with VLP diets. Forty-eight piglets were assigned to six treatments: positive control (PC), negative control (NC), and NC containing LAA 25%, LAA 50%, LAA + BCAA 25% (LB25) and LAA + BCAA 50% (LB50) more than recommendations.

Results

Relative to PC or NC, LB25 and LB50 had higher digestibility of Ca and plasma Ca and phosphorus (P), but lower plasma vitamin D₃. LB50 tended to increase vitamin D receptor transcript and protein in the gut, but decreased mRNA or protein abundance of parathyroid hormone 1 receptor (PTH1R), calbindin 1 (CALB1), cytochrome P450 family 27 subfamily B member 1 and occludin in small intestine. LB50 increased the transcript of cytochrome P450 family 24 subfamily A member 1 and PTH1R but decreased the transcript of transient receptor potential cation channel subfamily V member 5, CALB1 and solute carrier family 17 member 4 in kidney.

Conclusion

Overall, BCAA increased Ca digestibility through regulating the transcellular and paracellular Ca absorption in the gut and reabsorption in kidney during protein restriction.

Calcium Homeostasis and Bone Metabolism in Goats Fed a Low Protein Diet

The objective of this study was to investigate the effects of low-protein diets on blood calcium (Ca) level, bone metabolism, and the correlation between bone metabolism and blood calcium in goats. Twenty-four female Xiangdong black goats with similar body weight (19.55 ± 3.55 kg) and age (8.0 ± 0.3 months) were selected and allocated into two groups: control group (CON, 10.77% protein content) and low-protein group (LP, 5.52% protein content). Blood samples were collected on days 1, 4, 7, 16 and 36 before morning feeding to determine the concentration of calcium (Ca), parathyroid hormone (PTH), bone gla protein (BGP), C-terminal telopeptide of type 1 collagen (CTX-1), bone alkaline phosphatase (BALP), and 1, 25-dihydroxyvitamin D3 [1,25(OH)₂D3]. Liver samples were collected to determine the expression of bone metabolism-related genes. There was no difference observed between LP and CON in concentration of plasma Ca or any of bone metabolism markers (P > 0.05). In the liver, the mRNA expression of bone gamma carboxyglutamate protein (BGLAP), alkaline phosphatase (ALPL), and mothers against decapentaplegic homolog-1 (SMAD1) were increased (P < 0.05) in LP as compared with CON. The correlation analysis of Ca and bone metabolism markers showed no significant correlation between Ca and bone metabolism. These results suggest that the blood Ca concentration in mature goats may keep at a stable level through nitrogen cycling when the providing protein is not enough.

Dual activities of oxidation and oxidative decarboxylation by flavoenzymes

Specific flavoenzyme oxidases catalyze oxidative decarboxylation in addition to their classical oxidation reactions in the same active sites. The mechanisms underlying oxidative decarboxylation by these enzymes and how they control their two activities are not clearly known. This article reviews the current state of knowledge of four enzymes from the l-amino acid oxidase and l-hydroxy acid oxidase families, including l-tryptophan 2-monooxygenase, l-phenylalanine 2-oxidase and l-lysine oxidase/monooxygenase and lactate monooxygenase which catalyze substrate oxidation and oxidative decarboxylation. Apart from specific interactions to allow substrate oxidation by the flavin cofactor, specific binding of oxidized product in the active sites appears to be important for enabling subsequent decarboxylation by these enzymes. Based on recent findings of l-lysine oxidase/monooxygenase, we propose that nucleophilic attack of H2O2 on the imino acid product is the mechanism enabling oxidative decarboxylation.

The Effects of Milk Supplementation on Bone Health Indices in Adults: A Meta-Analysis of Randomized Controlled Trials

Milk contains a number of bone-beneficial nutrients. However, milk, due to the D-galactose content, might have unfavorable effects on bone health. A meta-analysis of randomized controlled trials (RCTs) was performed to clarify the effects of milk supplementation on bone mineral density (BMD), bone turnover markers [N-terminal telopeptide of type I collagen (NTx), C-terminal telopeptide of type 1 collagen (CTx), osteocalcin, bone alkaline phosphatase (BALP), and procollagen type 1 N-propeptide (P1NP)], and hormonal indices related to bone metabolism [parathyroid hormone (PTH), 25-hydroxyvitamin D [25(OH)D], and insulin-like growth factor 1 (IGF-1)] in adults. The PubMed and Web of Science databases were searched. A random-effects model was used to estimate the pooled effect sizes. A total of 20 RCTs were included. The trial duration ranged from 1 mo to 36 mo. Milk supplementation resulted in a small but significant increase in BMD at the hip (+0.004 g/cm2; n = 9 RCTs) and lumbar spine (+0.025 g/cm2; n = 7), but did not significantly affect whole-body BMD (n = 3) and femoral neck BMD (n = 7). Milk supplementation reduced the concentrations of P1NP (-5.20 ng/mL; n = 9), CTx (-0.16 ng/mL; n = 9), and NTx (-8.66 nmol bone collagen equivalents/mmol creatinine; n = 3). The concentrations of osteocalcin (n = 9) and BALP (n = 3) were not affected by milk supplementation. Reduced parathyroid hormone PTH (-1.01 pg/mL; n = 13) concentrations and increased IGF-1 (+1.79 nmol/l; n = 4) concentrations were observed with milk supplementation. 25(OH)D (+3.73 ng/mL; n = 11) concentrations were increased with vitamin-D fortified milk supplementation. The addition of milk to the diet may potentially increase the likelihood of preventing bone loss by restoring bone homeostasis through the modulation of the calcium-vitamin D-PTH axis, bone remodeling rate, and growth hormone/IGF-1 axis.

A Review on the Enhancement of Calcium Phosphate Cement with Biological Materials in Bone Defect Healing

Calcium phosphate cement (CPC) is a promising material used in the treatment of bone defects due to its profitable features of self-setting capability, osteoconductivity, injectability, mouldability, and biocompatibility. However, the major limitations of CPC, such as the brittleness, lack of osteogenic property, and poor washout resistance, remain to be resolved. Thus, significant research effort has been committed to modify and reinforce CPC. The mixture of CPC with various biological materials, defined as the materials produced by living organisms, have been fabricated by researchers and their characteristics have been investigated in vitro and in vivo. This present review aimed to provide a comprehensive overview enabling the readers to compare the physical, mechanical, and biological properties of CPC upon the incorporation of different biological materials. By mixing the bone-related transcription factors, proteins, and/or polysaccharides with CPC, researchers have demonstrated that these combinations not only resolved the lack of mechanical strength and osteogenic effects of CPC but also further improve its own functional properties. However, exceptions were seen in CPC incorporated with certain proteins (such as elastin-like polypeptide and calcitonin gene-related peptide) as well as blood components. In conclusion, the addition of biological materials potentially improves CPC features, which vary depending on the types of materials embedded into it. The significant enhancement of CPC seen in vitro and in vivo requires further verification in human trials for its clinical application.

Relationship Between Serum Amino Acid Levels and Bone Mineral Density: A Mendelian Randomization Study

BACKGROUND

This study aimed to explore the association between serum amino acids (AAs) levels and bone mineral density (BMD).

METHODS

We performed a two-sample Mendelian randomization (MR) analysis to analyze the associations between the levels of eight AAs and BMD values by using summary-level genome-wide association study (GWAS) data. We applied the MR Steiger filtering method and MR Pleiotropy RESidual Sum and Outlier (MR-PRESSO) global test to check for and remove single nucleotide polymorphisms (SNPs) that were horizontally pleiotropic. The associations were estimated with the inverse variance weighted (IVW), MR-Egger, weighted median and MR Robust Adjusted Profile Score (MR.RAPS) methods.

RESULTS

Our study found that genetically increased isoleucine (Ile) [IVW: effect = 0.1601, 95% confidence interval (CI) = 0.0604 ~ 0.2597, p = 0.0016] and valine (Val) levels (IVW: effect = 0.0953, 95% CI = 0.0251 ~ 0.1655, p = 0.0078) were positively associated with total body BMD (TB-BMD). The results also revealed that genetically increased tyrosine (Tyr) levels were negatively associated with TB-BMD (IVW: effect = -0.1091, 95% CI = -0.1863 ~ -0.0320, p = 0.0055).

CONCLUSIONS

In this study, associations between serum AA levels and BMD were established. These findings underscore the important role that serum AAs play in the development of osteoporosis and provide evidence that osteoporosis can be prevented and treated by the intake of certain AAs.

Dietary tryptophan and bone health: a cross-sectional, population-based study

Tryptophan metabolites influence bone. We aimed to investigate the relationship between dietary tryptophan and bone health in a population-based sample of men and women. Following adjustment for age, dietary tryptophan was not associated with bone quantity or quality, suggesting a non-critical role of superfluous tryptophan on the skeleton.

PURPOSE

Tryptophan metabolites, such as serotonin, influence bone. We sought to determine the relationship between dietary intake of tryptophan and bone health in a population-based study of men and women.

METHODS

Participants (1033 women and 900 men, aged 20-98 years) enrolled in the Geelong Osteoporosis Study (GOS) were investigated. Dietary information was collected using a validated questionnaire. Tryptophan levels were calculated (mg/day) in accordance with Food Standards Australia and New Zealand and dichotomised according to the median. Bone mineral density (BMD; g/cm²) was measured at the spine (postero-anterior projection) and total hip using dual-energy X-ray absorptiometry. Stiffness index (SI), broadband ultrasound attenuation (BUA) and speed of sound (SOS) were derived from quantitative heel ultrasound. Linear regression models were used to test associations between dietary tryptophan and bone health, after adjustment for potential confounders.

RESULTS

Tryptophan intakes ranged from 112 to 3796 mg/day (median 1035) in men and 115-2869 mg/day (median 885) in women. In men older than 45 years and women, a high tryptophan intake was associated with greater hip BMD compared to participants with a low tryptophan intake (p = 0.002 and p = 0.04, respectively); however, these relationships were attenuated by age (all p > 0.05). Participants with high tryptophan intake had greater BUA and SI compared to participants with low tryptophan intake (men; BUA, p = 0.02 and SI, p = 0.02, and women; BUA, p = 0.03 and SI, p = 0.08), yet also attenuated by age (all p > 0.05).

CONCLUSION

No association was found between tryptophan intake and bone health in this population, which suggests a non-critical role of superfluous tryptophan consumption on the skeleton.

The effect of different dietary ratios of lysine, arginine and methionine on biochemical parameters and hormone secretion in turkeys

We postulated that the use of optimal levels and proportions of Lys, Arg and Met in compound feed allows for optimal exploitation of the growth potential of contemporary slaughter turkey hybrids and reduces metabolic disorders. The aim of the study was to determine the effect of different proportions of Lys, Arg and Met in diets whose Lys content is in accordance with NRC recommendations, that is a low level, on selected parameters of protein, lipid and carbohydrate metabolism and on hormone secretion in turkeys. The lowest Arg content (90% Lys) in the diet resulted in an increase in plasma total cholesterol levels in the turkeys as compared to higher Arg content (100% or 110% of Lys), (2.50 vs. 2.09 vs. 1.83). Plasma HDL and creatinine concentration increased in turkeys fed diets with higher Arg content (100% and 110% Lys) compared to turkeys receiving the diet with the lowest Arg content (90% Lys). Compared to turkeys receiving the lowest and intermediate Arg content (90% and 100% Lys), the diet with the highest content of this AA (110% Lys) resulted in an increase in the plasma T4 level (71.21 vs. 86.60 vs. 128.2). The varied Arg and Met levels relative to Lys did not affect the secretion of neurotransmitters or hormones regulating glucose metabolism. At low levels of Met in the diet, an decrease in Arg relative to Lys from 100% to 90% caused a growth depression of turkeys (10.68 vs. 10.21 kg), which was not noted in the case of the higher Met content. When using the Lys level recommended by NRC in the turkey diet, the optimal Arg level is 100% and Met is 45% compared to Lys.

Markers of Bone Health and Impact of Whey Protein Supplementation in Army Initial Entry Training Soldiers: A Double-Blind Placebo-Controlled Study

Training civilians to be soldiers is a challenging task often resulting in musculoskeletal injuries, especially bone stress injuries. This study evaluated bone health biomarkers (P1NP/CTX) and whey protein or carbohydrate supplementations before and after Army initial entry training (IET). Ninety male IET soldiers participated in this placebo-controlled, double-blind study assessing carbohydrate and whey protein supplementations. Age and fat mass predicted bone formation when controlling for ethnicity, explaining 44% (p < 0.01) of bone formation variations. Age was the only significant predictor of bone resorption (p = 0.02) when controlling for run, fat, and ethnicity, and these factors together explained 32% of the variance in bone resorption during week one (p < 0.01). Vitamin D increased across training (p < 0.01). There was no group by time interaction for supplementation and bone formation (p = 0.75), resorption (p = 0.73), Vitamin D (p = 0.36), or calcium (p = 0.64), indicating no influence of a supplementation on bone biomarkers across training. Age, fitness, fat mass, and ethnicity were important predictors of bone metabolism. The bone resorption/formation ratio suggests IET soldiers are at risk of stress injuries. Male IET soldiers are mildly to moderately deficient in vitamin D and slightly deficient in calcium throughout training. Whey protein or carbohydrate supplementations did not affect the markers of bone metabolism.

Cocrystallization of 5-fluorouracil and l-phenylalanine: the first zwitterionic cocrystal of 5-fluorouracil with amino acid exhibiting perfect in vitro/vivo pharmaceutical properties

The first zwitterionic cocrystal of 5-fluorouracil with amino acid has been prepared and its structure and in vitro/vivo properties have been systematically studied.

Circulating amino acids are associated with bone mineral density decline and ten-year major osteoporotic fracture risk in older community-dwelling adults

With aging, poor bone mineral density (BMD) and accelerated decrease in BMD are strong risk factors for fracture. Reports of the associations of dietary protein intake with bone strength are inconsistent, possibly owing to differences in protein sources and amino acid (AA) composition. We examined the associations of serum AA with 4-year hip BMD loss and subsequent fracture risk within 10 years in older community-dwelling adults, and further addressed whether lifestyle, dietary protein intake and its source, and body composition would affect the associations. In 1424 men and 1573 women (mean age 72 years), using binary logistic regression, higher serum valine, leucine, isoleucine and tryptophan concentrations were associated (or approaching a borderline significance in case of the last three ones) with less hip BMD decline (defined as BMD loss ≥ 2.8 times the precision error of the BMD measurement at femoral neck) in 4 years later, with the OR (95%CI) /SD of AA increase, ranging from 0.83 (0.75, 0.91) to 0.92 (0.87, 0.98) after multiple adjustments for baseline age, gender, BMI, BMD, estimated glomerular filtration rate (eGFR), dietary protein intake (animal- and plant-derived protein intakes), calcium intake, established lifestyles (physical activity level, smoking and alcohol drinking status), osteoporosis medications, and changes of body fat and lean muscle mass. Higher serum total homocysteine (tHcy) concentration was independently associated with BMD decline 4 years later (OR (95%CI) /SD of 1.16 (1.05, 1.27)). Using multivariate Cox regression, higher serum tryptophan concentration potentially predicted low risk of incident major osteoporotic fractures (MOFs) (HR/SD (95%CI)=0.86 (0.75, 0.98)) after multiple adjustments. Higher serum tHcy was associated with MOFs (HR/SD (95%CI)=1.29 (1.12, 1.50)) risk after multiple adjustments in men. These findings suggest that a specific AA profile correlates with greater BMD and lower subsequent fracture risk, independent of diet and lifestyle factors.

L-Amino Acids Promote Calcitonin Release via a Calcium-Sensing Receptor: Gq/11-Mediated Pathway in Human C-Cells

Human calcitonin release is promoted by elevated extracellular Ca2+ (Ca2+o) concentration acting, at least in part, via the calcium-sensing receptor (CaSR). The CaSR is positively modulated by L-amino acids, including the aromatic amino acids L-phenylalanine (Phe) and L-tryptophan (Trp). To investigate the effect of L-amino acids on human calcitonin secretion, we selected thyroid TT cells and exposed them to various Ca2+o concentrations in the absence or presence of L-Phe, plasma-like mixtures of L-amino acids, or the clinically effective positive modulator (calcimimetic) cinacalcet. In the presence of L-Phe or plasma-like mixtures of amino acids, TT cells exhibited enhanced Ca2+o sensitivity in assays of calcitonin release and intracellular Ca2+ mobilization. Furthermore, the effect of elevated Ca2+o and L-Phe on calcitonin release was markedly suppressed by the calcilytic NPS-2143. These effects were dependent on CaSR-mediated activation of Gq/11 as revealed by the specific inhibitor YM-254890. The findings support the hypothesis that calcitonin release is stimulated by increases in plasma L-amino acid levels as well as elevated Ca2+o concentration. They also demonstrate that stimulated calcitonin release as well as basal levels of calcitonin secretion are mediated by a CaSR:Gq/11 signaling mechanism.

Metabolomics reveals citric acid secretion in mechanically-stimulated osteocytes is inhibited by high glucose

Osteocytes are the main cells of bone tissue and play a crucial role in bone formation and resorption. Recent studies have indicated that Diabetes Mellitus (DM) affects bone mass and potentially causes higher bone fracture risk. Previous work on osteocyte cell cultures has demonstrated that mechanotransduction is impaired after culture under diabetic pre-conditioning with high glucose (HG), specifically osteoclast recruitment and differentiation. The aim of this study was to analyze the extracellular metabolic changes of osteocytes regarding two conditions: pre-conditioning to either basal levels of glucose (B), mannitol (M) or HG cell media, and mechanical stimulation by fluid flow (FF) in contrast to static condition (SC). Secretomes were analyzed using Liquid Chromatography and Capillary Electrophoresis both coupled to Mass Spectrometry (LC-MS and CE-MS, respectively). Results showed the osteocyte profile was very similar under SC, regardless of their pre-conditioning treatment, while, after FF stimulation, secretomes followed different metabolic signatures depending on the pre-conditioning treatment. An important increment of citrate pointed out that osteocytes release citrate outside of the cell to induce osteoblast activation, while HG environment impaired FF effect. This study demonstrates for the first time that osteocytes increase citrate excretion under mechanical stimulation, and that HG environment impaired this effect.

Improving osteogenesis of calcium phosphate bone cement by incorporating with lysine: An in vitro study

Calcium phosphate bone cement (CPC) has attracted extensive interests from surgeons and material scientists. However, its actual application is still limited because of its poor osteogenesis. In this work, lysine, one of the essential components of proteins, was incorporated into the CPC to improve its osteogenesis ability. Effects of lysine on the phase, morphology, physicochemical properties, protein adsorption, lysine release and cytocompatibility of CPC were investigated. Results showed that lysine had no significant influence on the phase and morphology of the hydrated cements, but evidently raised the compressive strength, apparent porosity and setting time of the cements in a content-dependent manner of lysine. In contrast to the control, the lysine-incorporated CPCs had notably enhanced in vitro osteogenesis capability. It was supposed to be synergistically attributed to the improvements of fibronectin (FN) anchoring and bone mesenchymal stem cells (BMSCs) adhesion on the hydrated cements as well as the sustained release of bioactive amino acid molecules. Hence, lysine was expected to be applied as a novel bioactive admixture in the development of CPC with the improved osteogenesis ability and physicochemical properties for numerous orthopedic applications.

Impact of Protein and Carbohydrate Supplementation on Musculoskeletal Injuries in Army Initial Entry Training Soldiers

This project investigated whey protein and/or carbohydrate supplementation effects on musculoskeletal injury (MSI) outcomes. Four groups of Initial Entry Training soldiers consumed either: (1) one protein (38.6 g, 293 kcal); (2) one carbohydrate (63.4 g, 291 kcal); (3) two protein (77.2 g, 586 kcal); or (4) two carbohydrate servings/day (126.8 g, 582 kcal) after physical training and before bed, or before bed only. Odds Ratio, Chi-square and Wilcoxon ranked-sum test compared supplementation/no supplementation, number of servings, and protein/carbohydrate for MSI and limited/missed duty rates and limited/missed training days. Non-matched pairs group averages were compared to 2015/2016 historical data. Non-supplemented soldiers were approximately 5× more likely to sustain a MSI (χ2 = 58.48, p < 0.001) and 4× more likely to miss training (χ2 = 9.73, p = 0.003) compared to two servings. Non-supplemented soldiers missed five additional training days compared to two servings (W = 6059.5, p = 0.02). Soldiers consuming one serving were approximately 3× more likely to sustain a MSI than two servings (χ2 = 9.55, p = 0.002). There was no difference in limited/missed duty rates or limited/missed training days between consuming one or two servings. There was no difference between consuming one serving versus no supplementation or protein versus carbohydrate supplementation for any outcome variable. Soldiers consuming 2 servings/day of protein or carbohydrate had lower MSI rates, limited/missed duty rates, and limited/ missed training days compared to non-supplemented soldiers.

Estimation of energy balance and training volume during Army Initial Entry Training

BACKGROUND

Adequate dietary intake is important for promoting adaptation and prevention of musculoskeletal injury in response to large volumes of physical training such as Army Initial Entry Training (IET). The purpose of this study was to evaluate training volume and dietary intake and estimate energy balance in Army IET soldiers.

METHODS

Dietary intake was assessed by collecting diet logs for three meals on each of three, non-consecutive days during the first week of IET. Training volume was measured across 13 weeks of training using Actigraph wGT3X accelerometers. Training intensity was classified using Sasaki vector magnitude three cut points. Energy expenditure estimates were calculated during weeks two and three of training using the modified Harris-Benedict equation and by estimation of active energy expenditure using metabolic equivalents for each classification of physical activity. All data is presented as mean ± standard deviation.

RESULTS

A total of 111 male soldiers (ht. = ± 173 ± 5.8 cm, age = 19 ± 2 years, mass = 71.6. ± 12.4 kg) completed diet logs and were monitored with Actigraphs. IET soldiers performed on average 273 ± 62 min low, 107 ± 42 min moderate, 26 ± 22 min vigorous, and 10 ± 21 min of very vigorous intensity physical activity daily across 13 weeks. The estimated total daily energy expenditure was on average 3238 ± 457 kcals/d during weeks two and three of IET. Compared to week one caloric intake, there was a caloric deficit of 595 ± 896 kcals/d on average during weeks two and three of IET. Regression analysis showed that body weight was a significant predictor for negative energy balance (adj. R2 = 0.54, p < 0.001), whereby a 1 kg increase in body mass was associated with a 53 kcal energy deficit.

CONCLUSIONS

Based on week one dietary assessment, IET soldiers did not consume adequate calories and nutrients to meet training needs during red phase (weeks one through three). This may directly affect soldier performance and injury frequency. IET soldiers undergo rigorous training, and these data may help direct future guidelines for adequate nourishment to optimize soldier health and performance.

Influence of Ternary Complexation between Bovine Serum Albumin, Sodium Phytate, and Divalent Salts on Turbidity and In Vitro Digestibility of Protein

Phytate decreases mineral and protein availability and influences protein properties, such as solubility and stability. The binding constants and turbidity data can help with the understanding of the influence of phytate and divalent salts on protein behavior. Ternary complexes formed between bovine serum albumin, sodium phytate, and divalent salts were investigated by isothermal titration calorimetry, turbidity, and in vitro protein digestibility. Results showed a positive entropy change and a negative and small enthalpy change as a result of electrostatic binding forces and ternary and binary complex precipitation. The interaction was favored for the systems containing calcium and manganese, whereas those containing magnesium showed a low heat of interaction. Despite the high protein digestibility, the stability of divalent phytates in a wide pH range may decrease mineral bioavailability. These results can provide important insights for the study of mineral bioavailability and diverse processes that involve protein and minerals in several areas of knowledge.

The effect of meals on bone turnover - a systematic review with focus on diabetic bone disease

INTRODUCTION

Type 2 diabetes is associated with an increased risk of bone fractures. Bone mineral density (BMD) is increased and bone turnover is low in type 2 diabetes and the increased BMD does not explain the increased fracture risk. However, the low bone turnover may lead to insufficient bone renewal with unrepaired micro-cracks and thus increase fracture risk. Ingestion of food acutely decreases bone resorption markers and the macronutrient composition of meals and meal frequency may influence bone metabolism adversely in subjects with unhealthy eating patterns, e.g., patients with type 2 diabetes.

AREAS COVERED

The treatment strategy of bone disease in type 2 diabetics is covered in this review. The current management of diabetic bone disease consists of anti-osteoporotic treatment. However, anti-resorptives may further reduce an already low bone turnover with uncertain effects. Furthermore, the acute and long-term effects of meal ingestion, weight loss alone and in combination with exercise as well as the possible underlying mechanisms are covered in this systematic review.

EXPERT COMMENTARY

Current management of diabetic bone disease is based on principles of anti-osteoporotic treatment in non-diabetic subjects. However, studies are urged to investigate whether anti-resorptives are equally beneficial in type 2 diabetes as in non-diabetic individuals.

Influence of dietary protein and its amino acid composition on postoperative outcomes after gastric bypass surgery: a systematic review

CONTEXT

Bariatric surgery is an effective method to reduce morbid obesity. Nutritional counseling is essential to achieve maximal treatment success and to avoid long-term complications. Increased dietary protein intake may improve various postoperative results.

OBJECTIVE

The aim of this systematic review is to examine the relationship between intake of dietary protein or supplementation with amino acids and postoperative outcomes after gastric bypass surgery.

DATA SOURCES

A systematic literature search was conducted in 4 electronic databases: Cochrane, Embase, PubMed, and Scopus.

STUDY SELECTION

The initial search retrieved 7333 hits, which included 2390 duplicates.

DATA EXTRACTION

Tweny-three studies with varying study designs, interventions, and outcomes were included.

RESULTS

Studies did not provide convincing evidence of a beneficial effect on any postoperative outcome.

CONCLUSIONS

The study of the influence of protein and its amino acid composition represents an important developing domain of knowledge and warrants further attention considering the popularity of bariatric surgery. Future studies should include a clear description of the quantity and composition of proteins and amino acids in the diet or supplement.

Protein/amino-acid modulation of bone cell function

Nutrients (protein, carbohydrates and fats) have traditionally been thought of as fuels simply providing the energy for cellular metabolic activity. According to the classic view, if nutrients are available, then anabolic pathways are activated, and if nutrients are not available, catabolic pathways are activated. However, it is becoming increasingly clear that nutrient effects on bone cells (stem cells, osteoblasts and osteoclasts) are complex, some nutrients promote bone formation, whereas others interfere with bone formation or actually promote bone break down. At an organ level, nutrient intake can suppress bone breakdown and modulate the activity of the calcium/vitamin D/parathyroid hormone axis. At a cellular level, nutrient intake can impact cellular energetics either through a direct mechanism (binding or uptake of the nutrient into the cell) or indirect (by elevating nutrient-related hormones such as insulin, insulin-like growth factor 1 or incretin hormones). It is also becoming clear that within a nutrient class (for example, protein), individual components (that is, amino acids) can have markedly different effects on cell function and impact bone formation. The focus of this review will be on one nutrient class in particular, dietary protein. As the prevalence of inadequate dietary protein intake increases with age, these findings may have translational implications as to the optimal dietary protein content in the setting of age-associated bone loss.

Development of a pharmaceutical cocrystal with solution crystallization technology: Preparation, characterization, and evaluation of myricetin-proline cocrystals

Myricetin shows low oral bioavailability (<10%) in rats due to poor aqueous solubility, although it has demonstrated various pharmacological activities such as those related to anticancer, anti-diabetes, and hepatic protection. To overcome this issue, in this study, pharmaceutical cocrystals were designed to efficiently deliver myricetin by oral administration. A 1:2 stoichiometric cocrystal of myricetin with proline was prepared successfully by solution crystallization based on the ternary phase diagram (TPD) principle, and it is presented as a new sphericity-like crystalline phase characterized by differential scanning calorimetry (DSC), powder X-ray diffraction (PXRD), and scanning electron microscopy (SEM). The formation of myricetin-proline cocrystals was a spontaneous and exothermic process, probably due to the supramolecular interactions between themselves, which were determined by Fourier transform-infrared spectroscopy (FT-IR). Consequently, the dissolution efficiency of myricetin from cocrystals was increased 7.69-fold compared with that of coarse myricetin, and the oral bioavailability of myricetin cocrystals in rats was enhanced by approximately 3.03 times compared with that of pure myricetin. The present study provides useful information for the potential application of cocrystal technology for water-insoluble drugs, especially flavonoid compounds.

The Relationship Between Creatine and Whey Protein Supplements Consumption and Anesthesia in Rats

Background:

Because the trend of pharmacotherapy is toward controlling diet rather than administration of drugs, in our study we examined the probable relationship between Creatine (Cr) or Whey (Wh) consumption and anesthesia (analgesia effect of ketamine). Creatine and Wh are among the most favorable supplements in the market. Whey is a protein, which is extracted from milk and is a rich source of amino acids. Creatine is an amino acid derivative that can change to ATP in the body. Both of these supplements result in Nitric Oxide (NO) retention, which is believed to be effective in N-Methyl-D-aspartate (NMDA) receptor analgesia.

Objectives:

The main question of this study was whether Wh and Cr are effective on analgesic and anesthetic characteristics of ketamine and whether this is related to NO retention or amino acids’ features

Materials and Methods:

We divided 30 male Wistar rats to three (n = 10) groups; including Cr, Wh and sham (water only) groups. Each group was administered (by gavage) the supplements for an intermediate dosage during 25 days. After this period, they became anesthetized using a Ketamine-Xylazine (KX) and their time to anesthesia and analgesia, and total sleep time were recorded.

Results:

Data were analyzed twice using the SPSS 18 software with Analysis of Variance (ANOVA) and post hoc test; first time we expunged the rats that didn’t become anesthetized and the second time we included all of the samples. There was a significant P-value (P < 0.05) for total anesthesia time in the second analysis. Bonferroni multiple comparison indicated that the difference was between Cr and Sham groups (P < 0.021).

Conclusions:

The data only indicated that there might be a significant relationship between Cr consumption and total sleep time. Further studies, with rats of different gender and different dosage of supplement and anesthetics are suggested.