Search

This article presents a study on the use of urinary guanidino compounds (GCs) and ureido compounds (UCs) as biomarkers for cardiac surgery-associated acute kidney injury (CSA-AKI). The study utilized a benzylic rearrangement reaction and high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) to analyze the concentrations of GCs/UCs in urine samples from patients with CSA-AKI at different stages. The findings suggest that certain GC/UC metabolites show significant changes in concentration during CSA-AKI and could potentially serve as biomarkers for different stages of AKI. This research provides valuable resources and new therapeutic targets for further study on CSA-AKI. [Extracted from the article]

Lung cancer (LC) is one of the major malignant diseases threatening human health. The study aimed to identify the effect of citrulline on the malignant phenotype of LC cells and to further disclose the potential molecular mechanism of citrulline in regulating the development of LC, providing a novel molecular biological basis for the clinical treatment of LC. The effects of citrulline on the viability, proliferation, migration, and invasion of LC cells (A549, H1299) were validated by CCK‐8, colony formation, EdU, and transwell assays. The cell glycolysis was assessed via determining the glucose uptake, lactate production, ATP levels, extracellular acidification rate (ECAR), and oxygen consumption rate (OCR). RNA‐seq and molecular docking were performed to screen for citrulline‐binding target proteins. Western blotting experiments were conducted to examine the expression of related signaling pathway molecules. In addition, the impacts of citrulline on LC growth in vivo were investigated by constructing mouse models. Citrulline augmented the viability of LC cells in a concentration and time‐dependent manner. The proliferation, migration, invasion, glycolysis, and EMT processes of LC cells were substantially enhanced after citrulline treatment. Bioinformatics analysis indicated that citrulline could bind to RAB3C protein. Western blotting results indicated that citrulline activated the IL‐6/STAT3 pathway by binding to RAB3C. In addition, animal experiments disclosed that citrulline promoted tumor growth in mice. Citrulline accelerated the glycolysis and activated the IL6/STAT3 pathway through the RAB3C protein, consequently facilitating the development of LC. [ABSTRACT FROM AUTHOR]

Background: Arginine is a conditionally essential amino acid that is depleted in critically ill or surgical patients. In pediatric and adult patients, sepsis results in an arginine-deficient state, and the depletion of plasma arginine is associated with greater mortality. However, direct supplementation of arginine can result in the excessive production of nitric oxide (NO), which can contribute to the hypotension and macrovascular hypo-reactivity observed in septic shock. Pegylated arginine deiminase (ADI-PEG20, pegargiminase) reduces plasma arginine and generates citrulline that can be transported intracellularly to generate local arginine and NO, without resulting in hypotension, while maintaining microvascular patency. The objective of this study was to assess the efficacy of ADI-PEG20 with and without supplemental intravenous citrulline in mitigating hypovolemic shock, maintaining tissue levels of arginine, and reducing systemic inflammation in an endotoxemic pediatric pig model. Methods: Twenty 3-week-old crossbred piglets were implanted with jugular and carotid catheters as well as telemetry devices in the femoral artery to measure blood pressure, body temperature, heart rate, and respiration rate. The piglets were assigned to one of three treatments before undergoing a 5 h lipopolysaccharide (LPS) infusion protocol. Twenty-four hours before LPS infusion, control pigs (LPS; n=6) received saline, ADI-PEG20 pigs (n=7) received an injection of ADI-PEG20, and seven pigs (ADI-PEG20 + CIT pigs [n=7]) received ADI-PEG20 and 250 mg/kg citrulline intravenously. Pigs were monitored throughout LPS infusion and tissue was harvested at the end of the protocol. Results: Plasma arginine levels decreased and remained low in ADI-PEG20 + CIT and ADI-PEG20 pigs compared with LPS pigs but tissue arginine levels in the liver and kidney were similar across all treatments. Mean arterial pressure in all groups decreased from 90 mmHg to 60 mmHg within 1 h of LPS infusion but there were no significant differences between treatment groups. ADI-PEG20 and ADIPEG20 + CIT pigs had less CD45+ infiltrate in the liver and lung and lower levels of pro-inflammatory cytokines in the plasma. Conclusion: ADI-PEG20 and citrulline supplementation failed to ameliorate the hypotension associated with acute endotoxic sepsis in pigs but reduced systemic and local inflammation in the lung and liver. [ABSTRACT FROM AUTHOR]

Simple Summary: L-citrulline, as a non-essential amino acid, is recognized for its effectiveness in enhancing arginine bioavailability and nitric oxide (NO) synthesis, drawing significant attention from the scientific community for its potential to improve athletic performance. This study investigated the effects of L-citrulline supplementation on the racing performance of Yili horses as well as on the blood acid–base balance, physiological and biochemical blood indices, and antioxidant markers before and after an exercise. Additionally, changes in the plasma amino acid metabolism and polyamine levels were examined. The results indicate that the supplementation of 50 g of L-citrulline to the horses' diet significantly increased the plasma concentrations of citrulline and arginine and provided a certain improvement in the athletic performance of the Yili horses. Additionally, compared to a control group, the total protein and lactate dehydrogenase levels were significantly elevated 2 h before and 2 h after the race, while the lactate concentration immediately post-race was significantly reduced. The objective of this study was to evaluate the effects of pre-exercise L-citrulline supplementation on the athletic performance of Yili speed-racing horses during a high-intensity exercise. On the 20th day of the experiment, blood samples were collected at 3 h and 6 h post-supplementation to measure the amino acid and polyamine concentrations. On the 38th day of the experiment, the horses participated in a 2000 m speed race, and three distinct blood samples were gathered for assessing blood gases, hematological parameters, the plasma biochemistry, antioxidant parameters, and NO concentrations. The results indicate that the L-citrulline group showed a significant increase in the plasma citrulline and arginine concentrations. Conversely, the concentrations of alanine, serine, and threonine were significantly decreased. The glycine concentration decreased significantly, while there was a trend towards an increase in the glutamine concentration. Additionally, the levels of putrescine and spermidine in the plasma of the L-citrulline group were significantly increased. In terms of exercise performance, L-citrulline can improve the exercise performance of sport horses, significantly reduce the immediate post-race lactate levels in Yili horses, and accelerate the recovery of blood gas levels after an exercise. Furthermore, in the L-citrulline group of Yili horses, The levels of the total protein of plasma, superoxide dismutase, catalase, and lactate dehydrogenase were significantly increased both 2 h before and 2 h after the race. The total antioxidant capacity showed a highly significant increase, while the malondialdehyde content significantly decreased. In the immediate post-race period, the creatinine content in the L-citrulline group significantly increased. In conclusion, this study demonstrates that L-citrulline supplementation can influence the circulating concentrations of L-citrulline and arginine in Yili horses, enhance the antioxidant capacity, reduce lactate levels, and improve physiological and biochemical blood parameters, thereby having a beneficial effect on the exercise performance of athletic horses. [ABSTRACT FROM AUTHOR]

Pseudomonas fragi (P. fragi) is usually detected in low-temperature meat products, and seriously threatens food safety and human health. Therefore, the study investigated the antibacterial mechanism of linalool against P. fragi from membrane damage and metabolic disruption. Results from field-emission transmission electron microscopy (FETEM) and atomic force microscopy (AFM) showed that linalool damage membrane integrity increases surface shrinkage and roughness. According to Fourier transform infrared (FTIR) spectra results, the components in the membrane underwent significant changes, including nucleic acid leakage, carbohydrate production, protein denaturation and modification, and fatty acid content reduction. The data obtained from amino acid metabolomics indicated that linalool caused excessive synthesis and metabolism of specific amino acids, particularly tryptophan metabolism and arginine biosynthesis. The reduced activities of glucose 6-phosphate dehydrogenase (G6PDH), malate dehydrogenase (MDH), and phosphofructokinase (PFK) suggested that linalool impair the respiratory chain and energy metabolism. Meanwhile, genes encoding the above enzymes were differentially expressed, with pfkB overexpression and zwf and mqo downregulation. Furthermore, molecular docking revealed that linalool can interact with the amino acid residues of G6DPH, MDH and PFK through hydrogen bonds. Therefore, it is hypothesized that the mechanism of linalool against P. fragi may involve cell membrane damage (structure and morphology), disturbance of energy metabolism (TCA cycle, EMP and HMP pathway) and amino acid metabolism (cysteine, glutamic acid and citrulline). These findings contribute to the development of linalool as a promising antibacterial agent in response to the food security challenge. [ABSTRACT FROM AUTHOR]

This study investigated the correlation between oxidative stress and blood amino acids associated with nitric oxide metabolism in adult patients with coronavirus disease (COVID-19) pneumonia. Clinical data and serum samples were prospectively collected from 100 adult patients hospitalized for COVID-19 between July 2020 and August 2021. Patients with COVID-19 were categorized into three groups for analysis based on lung infiltrates, oxygen inhalation upon admission, and the initiation of oxygen therapy after admission. Blood data, oxidative stress-related biomarkers, and serum amino acid levels upon admission were compared in these groups. Patients with lung infiltrations requiring oxygen therapy upon admission or starting oxygen post-admission exhibited higher serum levels of hydroperoxides and lower levels of citrulline compared to the control group. No remarkable differences were observed in nitrite/nitrate, asymmetric dimethylarginine, and arginine levels. Serum citrulline levels correlated significantly with serum lactate dehydrogenase and C-reactive protein levels. A significant negative correlation was found between serum levels of citrulline and hydroperoxides. Levels of hydroperoxides decreased, and citrulline levels increased during the recovery period compared to admission. Patients with COVID-19 with extensive pneumonia or poor oxygenation showed increased oxidative stress and reduced citrulline levels in the blood compared to those with fewer pulmonary complications. These findings suggest that combined oxidative stress and abnormal citrulline metabolism may play a role in the pathogenesis of COVID-19 pneumonia. [ABSTRACT FROM AUTHOR]

This article provides information on superficial necrolytic dermatitis (SND), a dermatologic condition that affects humans, dogs, and rarely cats. SND is often associated with metabolic disturbances and can be caused by glucagon-secreting tumors or hepatopathy. It is characterized by cutaneous lesions and is most commonly found in older, smaller-breed dogs. Diagnostic findings include increased alkaline phosphatase and alanine aminotransferase levels, as well as hypoaminoacidemia. The article discusses the cause, diagnosis, and treatment options for SND, emphasizing the importance of early recognition and treatment to improve survival times. The optimal treatment involves a combination of intravenous amino acid infusions, enteral supplements, and high-protein home-cooked diets. [Extracted from the article]

Patients with phenylketonuria (PKU) must restrict their intake of phenylalanine, which can also affect the levels of other essential and non-essential amino acids due to inadequate supply. Therefore, our objective was to assess amino acids in serum samples from 20 PKU patients and compare them with results from 51 healthy subjects. A sample analysis was conducted using liquid chromatography–tandem mass spectrometry. We obtained levels of 28 substances, including amino acids, biogenic amines, carnitine, and acetylcarnitine. Kynurenine (p = 0.000001), tyrosine (p = 0.0002), asparagine (p = 0.001), proline (p = 0.012), and the kynurenine/tryptophan ratio (p < 0.000001) were identified as features that differed between the studied groups, being significantly lower in patients with PKU. Glycine (p = 0.000012), putrescine (p = 0.0055), asymmetric dimethylarginine (p = 0.01), creatinine (p = 0.035) levels, as well as the total level of glucogenic amino acids (p = 0.0018), and the ratios of putrescine/ornithine (p = 0.003) and citrulline/ornithine (p = 0.0043) were significantly higher in the PKU group. In conclusion, the amino acid profiles in patients with PKU differ significantly from those in healthy peers, with potential clinical implications. These findings confirm the importance of metabolic testing in clinical practice and highlight the necessity for adequate dietary monitoring and adjustment. [ABSTRACT FROM AUTHOR]

Aqueous zinc ion batteries are promising candidates for large‐scale energy storage. Nonetheless, the stability of Zn anodes in aqueous electrolytes is compromised by dendritic growth and undesirable side reactions. In this article, citrulline (Cit), a biocompatible compound, is investigated as an electrolyte additive to achieve superior stability of Zn anodes. Experimental results and theoretical calculations demonstrate that the Cit, serving as a bifunctional additive, possesses abundant highly polar groups (─NH2 and ─COOH) that facilitate strong interactions with Zn2+ and Zn metal. This dual regulation of the Zn2+ solvation shell and the electrical double layer at the anode/electrolyte interface effectively mitigates dendrite growth and suppresses interface side reactions, resulting in exceptional stability of Zn anode. Consequently, Zn||Zn symmetric batteries incorporating the Cit additive exhibit stable operation for over 1600 h at 1.0 mA cm−2 and 1.0 mAh cm−2, and maintain stable cycling for 650 h even under demanding conditions of 10.0 mA cm−2 and 10.0 mAh cm−2, corresponding to an ultra‐high cumulative plated capacity of 3.25 Ah cm−2. Furthermore, Zn||Cu asymmetric batteries achieve a remarkable Coulombic efficiency of 99.6% at 1.0 mA cm−2 and 0.5 mAh cm−2. These advancements also extend to the improved performance of assembled full batteries. [ABSTRACT FROM AUTHOR]

Introduction: Proliferative diabetic retinopathy (PDR) is a common diabetes complication, significantly impacting vision and quality of life. Previous studies have suggested a potential link between arginine pathway metabolites and diabetic retinopathy (DR). Connective tissue growth factor (CTGF) plays a role in the occurrence and development of fibrovascular proliferation (FVP) in PDR patients. However, the relationship between arginine pathway metabolites and FVP in PDR remains undefined. This study aimed to explore the correlation between four arginine pathway metabolites (arginine, asymmetric dimethylarginine[ADMA], ornithine, and citrulline) and the severity of FVP in PDR patients. Methods: In this study, plasma and aqueous humor samples were respectively collected from 30 patients with age-related cataracts without diabetes mellitus (DM) and from 85 PDR patients. The PDR patients were categorized as mild-tomoderate or severe based on the severity of fundal FVP. The study used KruskalWallis test to compare arginine, ADMA, ornithine, and citrulline levels across three groups. Binary logistic regression identified risk factors for severe PDR. Spearman correlation analysis assessed associations between plasma and aqueous humor metabolite levels, and between ADMA and CTGF levels in aqueous humor among PDR patients. Results: ADMA levels in the aqueous humor were significantly greater in patients with severe PDR than in those with mild-to-moderate PDR(P=0.0004). However, the plasma and aqueous humor levels of arginine, ornithine, and citrulline did not significantly differ between mild-to-moderate PDR patients and severe PDR patients (P>0.05). Binary logistic regression analysis indicated that the plasma (P=0.01) and aqueous humor (P=0.006) ADMA levels in PDR patients were risk factors for severe PDR. Furthermore, significant correlations were found between plasma and aqueous humor ADMA levels (r=0.263, P=0.015) and between aqueous humor ADMA and CTGF levels (r=0.837, P<0.001). Conclusion: Elevated ADMA levels in plasma and aqueous humor positively correlate with the severity of FVP in PDR, indicating ADMA as a risk factor for severe PDR. [ABSTRACT FROM AUTHOR]

Objective: The co-occurrence of kidney disease in patients with type 2 diabetes (T2D) is a major public health challenge. Although early detection and intervention can prevent or slow down the progression, the commonly used estimated glomerular filtration rate (eGFR) based on serum creatinine may be influenced by factors unrelated to kidney function. Therefore, there is a need to identify novel biomarkers that can more accurately assess renal function in T2D patients. In this study, we employed an interpretable machine-learning framework to identify plasma metabolomic features associated with GFR in T2D patients. Methods: We retrieved 1626 patients with type 2 diabetes (T2D) in Liaoning Medical University First Affiliated Hospital (LMUFAH) as a development cohort and 716 T2D patients in Second Affiliated Hospital of Dalian Medical University (SAHDMU) as an external validation cohort. The metabolite features were screened by the orthogonal partial least squares discriminant analysis (OPLS-DA). We compared machine learning prediction methods, including logistic regression (LR), support vector machine (SVM), random forest (RF), and eXtreme Gradient Boosting (XGBoost). The Shapley Additive exPlanations (SHAP) were used to explain the optimal model. Results: For T2D patients, compared with the normal or elevated eGFR group, glutarylcarnitine (C5DC) and decanoylcarnitine (C10) were significantly elevated in GFR mild reduction group, and citrulline and 9 acylcarnitines were also elevated significantly (FDR<0.05, FC > 1.2 and VIP > 1) in moderate or severe reduction group. The XGBoost model with metabolites had the best performance: in the internal validate dataset (AUROC=0.90, AUPRC=0.65, BS=0.064) and external validate cohort (AUROC=0.970, AUPRC=0.857, BS=0.046). Through the SHAP method, we found that C5DC higher than 0.1mmol/L, Cit higher than 26 mmol/L, triglyceride higher than 2 mmol/L, age greater than 65 years old, and duration of T2D more than 10 years were associated with reduced GFR. Conclusion: Elevated plasma levels of citrulline and a panel of acylcarnitines were associated with reduced GFR in T2D patients, independent of other conventional risk factors. [ABSTRACT FROM AUTHOR]

Simple Summary: L-Glutamate (Glu) and L-glutamine (Gln) are abundant amino acids in feedstuffs and ruminants. Dietary Gln is extensively utilized by ruminal microbes, but dietary Glu undergoes little catabolism by these microbes because they do not take up extracellular Glu due to the lack of the necessary transporters. Microbial proteins and dietary Glu exit the rumen into the abomasum and then the small intestine, where proteins undergo hydrolysis to release amino acids (including Glu and Gln) and small peptides for transport into enterocytes. Most dietary Gln escapes the underdeveloped rumen of preruminants, instead entering the abomasum and the small intestine. Within the enterocytes, Glu and Gln are extensively oxidized to provide ATP and are actively used to synthesize glutathione and other amino acids (alanine, ornithine, citrulline, arginine, proline, and aspartate), whereas Gln and aspartate are essential for purine and pyrimidine syntheses. Under normal feeding conditions, all diet- and rumen-derived Glu and Gln are extracted by the small intestine and, therefore, do not enter the portal circulation. De novo synthesis plays a crucial role in maintaining the homeostasis of Glu and Gln in the whole body but may be insufficient for maximal growth performance, production (e.g., lactation and pregnancy), and optimal health in ruminants. Dietary supplementation with Glu or Gln can safely improve the digestive, endocrine, and reproduction functions of ruminants and thus augment health and production parameters. Although both L-glutamate (Glu) and L-glutamine (Gln) have long been considered nutritionally nonessential in ruminants, these two amino acids have enormous nutritional and physiological importance. Results of recent studies revealed that extracellular Gln is extensively degraded by ruminal microbes, but extracellular Glu undergoes little catabolism by these cells due to the near absence of its uptake. Ruminal bacteria hydrolyze Gln to Glu plus ammonia and, intracellularly, use both amino acids for protein synthesis. Microbial proteins and dietary Glu enter the small intestine in ruminants. Both Glu and Gln are the major metabolic fuels and building blocks of proteins, as well as substrates for the syntheses of glutathione and amino acids (alanine, ornithine, citrulline, arginine, proline, and aspartate) in the intestinal mucosa. In addition, Gln and aspartate are essential for purine and pyrimidine syntheses, whereas arginine and proline are necessary for the production of nitric oxide (a major vasodilator) and collagen (the most abundant protein in the body), respectively. Under normal feeding conditions, all diet- and rumen-derived Glu and Gln are extensively utilized by the small intestine and do not enter the portal circulation. Thus, de novo synthesis (e.g., from branched-chain amino acids and α-ketoglutarate) plays a crucial role in the homeostasis of Glu and Gln in the whole body but may be insufficient for maximal growth performance, production (e.g., lactation and pregnancy), and optimal health (particularly intestinal health) in ruminants. This applies to all types of feeding systems used around the world (e.g., rearing on a milk replacer before weaning, pasture-based production, and total mixed rations). Dietary supplementation with the appropriate doses of Glu or Gln [e.g., 0.5 or 1 g/kg body weight (BW)/day, respectively] can safely improve the digestive, endocrine, and reproduction functions of ruminants to enhance their productivity. Both Glu and Gln are truly functional amino acids in the nutrition of ruminants and hold great promise for improving their health and productivity. [ABSTRACT FROM AUTHOR]

Objective: Amino acid (AA) metabolism plays a vital role in liver regeneration. However, its measuring utility for post-hepatectomy liver regeneration under different conditions remains unclear. We aimed to combine machine learning (ML) models with AA metabolomics to assess liver regeneration in health and non-alcoholic steatohepatitis (NASH). Methods: The liver index (liver weight/body weight) was calculated following 70% hepatectomy in healthy and NASH mice. The serum levels of 39 amino acids were measured using ultra-high performance liquid chromatography-tandem mass spectrometry analysis. We used orthogonal partial least squares discriminant analysis to determine differential AAs and disturbed metabolic pathways during liver regeneration. The SHapley Additive exPlanations algorithm was performed to identify potential AA signatures, and five ML models including least absolute shrinkage and selection operator, random forest, K-nearest neighbor (KNN), support vector regression, and extreme gradient boosting were utilized to assess the liver index. Results: Eleven and twenty-two differential AAs were identified in the healthy and NASH groups, respectively. Among these metabolites, arginine and proline metabolism were commonly disturbed metabolic pathways related to liver regeneration in both groups. Five AA signatures were identified, including hydroxylysine, L-serine, 3-methylhistidine, L-tyrosine, and homocitrulline in healthy group, and L-arginine, 2-aminobutyric acid, sarcosine, beta-alanine, and L-cysteine in NASH group. The KNN model demonstrated the best evaluation performance with mean absolute error, root mean square error, and coefficient of determination values of 0.0037, 0.0047, 0.79 and 0.0028, 0.0034, 0.71 for the healthy and NASH groups, respectively. Conclusion: The KNN model based on five AA signatures performed best, which suggests that it may be a valuable tool for assessing post-hepatectomy liver regeneration in health and NASH. [ABSTRACT FROM AUTHOR]

Purpose: Citrulline (CIT) and beetroot extract (BR) have separately shown benefits in rowing performance-related outcomes. However, effects of combined supplementation remain to be elucidated. The main purpose of this research was to study the effects of 1 week of daily co-supplementation of 3.5 g BR (500 mg NO3−) plus 6 g CIT on aerobic performance, maximal strength, and high-intensity power and peak stroke in elite male rowers compared to a placebo and to a BR supplementation. Methods: 20 elite rowers participated in this randomized, double-blind, placebo-controlled crossover trial completing 1 week of supplementation in each group of study: Placebo group (PLAG); BR group (BRG); and BR + CIT group (BR-CITG). 3 main physical tests were performed: aerobic performance, Wingate test and CMJ jump, and metabolic biomarkers and physiological outcomes were collected. Results: The Wingate all-out test showed no between-condition differences in peak power, mean power, relative power, or fatigue index (P > 0.05), but clearance of lactate was better in BR-CITG (P < 0.05). In the performance test, peak power differed only between PLAG and BR-CITG (P = 0.036), while VO2peak and maximum heart rate remained similar. CMJ jumping test results showed no between-condition differences, and blood samples were consistent (P > 0.200). Conclusion: Supplementation with 3.5 g of BR extract plus 6 g of CIT for 7 days improved lactate clearance after Wingate test and peak power in a performance test. No further improvements were found, suggesting longer period of supplementation might be needed to show greater benefits. [ABSTRACT FROM AUTHOR]

Citrulline (C6H13N3O3) is an amino acid found in the body as a zwitterion. This means its carboxylic and amine groups can act as Lewis donors to chelate metal cations. In addition, citrulline possesses a terminal ureido group on its aliphatic chain, which also appears to coordinate. Here, two new mixed complexes of citrulline were made with 1,10-phenanthroline and 2,2′-bipyridine. These compounds, once dissolved in water, gave aquo-complexes that were subject to DFT studies and in vitro toxicity studies on cancer cell lines (HeLa, MDA-MB-231, HCT 15, and MCF7) showed promising results. Docking studies with DNA were also conducted, indicating potential anticancer properties. [ABSTRACT FROM AUTHOR]

Malnourished patients with anorexia nervosa (AN) have lower plasma citrulline level compared to healthy controls. Citrulline is a non-essential amino-acid synthetized by the enterocyte and has functions affecting cardiovascular status. The aim of the study is to describe citrulline plasma level and to assess its relationship with hemodynamic status in a cohort of malnourished adult patients with AN. A retrospective observational study including malnourished patients with AN hospitalized between January 2018 and January 2019 for the treatment of severe malnutrition was carried out. Anthropometric measures, biochemical tests, and cardiac function indicators including doppler echocardiographic parameters were evaluated. Forty-eight patients with a median age of 29 [21–35.5] years old and body mass index (BMI) of 12 [10.5–-13.4] kg/m2 were included. Median systolic blood pressure (SBP) and median diastolic blood pressure (DBP) were respectively 99 [90–110] mmHg and 68 [59–73] mmHg. Median left ventricular ejection fraction (LVEF) was at 65 [58–69] %. Plasma citrulline level was under the normal range in 58% of patients and was positively correlated with fat mass, stroke volume, and left ventricular end diastolic volume, but not BMI. Citrulline level may be an innovative associated marker of hemodynamic status in malnourished patients with AN. Further research and prospective studies are needed to elucidate the specific pathways involved. [ABSTRACT FROM AUTHOR]

Simple Summary: The first and second limiting amino acids in ruminants 66 are methionine and lysine, respectively, and an appropriate lysine-to-methionine ratio is necessary for amino acid balance in a low-protein diet. A Lys/Met ratio of 1:1 increased the antioxidant capacity and the activities of digestive enzymes and reduced the production of ammonia nitrogen in Tibetan sheep. In addition, 16S rDNA sequencing revealed that a Lys/Met ratio of 1:1 significantly increased the Ace and Chao1 indices, and non-target metabolomics analysis revealed that cis-jasmone and Val-Asp-Arg could be involved in mediating the antioxidant capacity and increasing the activity of digestive enzyme activities in Tibetan sheep rumen. Phosphoric acid, one of the metabolic products, increased cellulase activity by regulating the abundance of Succiniclasticum through the oxidative phosphorylation pathway. In ruminants, supplementing appropriate amounts of amino acids improves growth, feed utilization efficiency, and productivity. This study aimed to assess the effects of different Lys/Met ratios on the ruminal microbial community and the metabolic profiling in Tibetan sheep using 16S rDNA sequencing and non-target metabolomics. Ninety-two-month-old Tibetan rams (initial weight = 15.37 ± 0.92 kg) were divided into three groups and fed lysine/methionine (Lys/Met) of 1:1 (LP-L), 2:1 (LP-M), and 3:1 (LP-H) in low-protein diet, respectively. Results: The T-AOC, GSH-Px, and SOD were significantly higher in the LP-L group than in LP-H and LP-M groups (p < 0.05). Cellulase activity was significantly higher in the LP-L group than in the LP-H group (p < 0.05). In the fermentation parameters, acetic acid concentration was significantly higher in the LP-L group than in the LP-H group (p < 0.05). Microbial sequencing analysis showed that Ace and Chao1 indicators were significantly higher in LP-L than in LP-H and LP-M (p < 0.05). At the genus level, the abundance of Rikenellaceae RC9 gut group flora and Succiniclasticum were significantly higher in LP-L than in LP-M group (p < 0.05). Non-target metabolomics analyses revealed that the levels of phosphoric acid, pyrocatechol, hydrocinnamic acid, banzamide, l-gulono-1,4-lactone, cis-jasmone, Val-Asp-Arg, and tropinone content were higher in LP-L. However, l-citrulline and purine levels were lower in the LP-L group than in the LP-M and LP-H groups. Banzamide, cis-jasmone, and Val-Asp-Arg contents were positively correlated with the phenotypic contents, including T-AOC, SOD, and cellulase. Phosphoric acid content was positively correlated with cellulase and lipase activities. In conclusion, the Met/Lys ratio of 1:1 in low-protein diets showed superior antioxidant status and cellulase activity in the rumen by modulating the microbiota and metabolism of Tibetan sheep. [ABSTRACT FROM AUTHOR]

Citrulline malate (CM) has been touted as a nutritional ergogenic aid for sports performance, with purported mechanisms of increased muscle blood flow, ammonia clearance, and adenosine triphosphate resynthesis. Combined, these physiological benefits may be best applied to whole-body endurance exercises, such as swimming, though this postulate has not yet been explored. In a double-blind, randomised, and crossover design, 11 national-level swimmers (age: 17 ± 3 years, height: 1.71 ± 0.05 m, body mass: 60.6 ± 8.3 kg) from a high-performance swimming club ingested either 15 g CM or a placebo (PLA) 60 min before six × 300 m freestyle bouts (at 4.5 min intervals). Blood lactate, blood pressure, and ratings of perceived exertion were measured at baseline, 60 min post-ingestion, and immediately post-exercise. Neither mean 300 m swimming time (CM: 212.0 ± 9.6 vs. PLA: 212.8 ± 7.7 s, p = 0.683, g = 0.09) nor any individual swimming bouts (p = 0.679, Pŋ2 = 0.02) were improved with CM ingestion. Moreover, no differences in any physiological or subjective measures were identified between conditions (all p > 0.05). Whether the proposed CM mechanisms were active was unclear as more direct physiological measures (i.e., plasma NO, ammonia) may have been required. Resultantly, these observations do not support an ergogenic effect of acute CM ingestion in highly trained swimmers. [ABSTRACT FROM AUTHOR]

Pyruvate carboxylase, a mitochondrial enzyme, catalyses the conversion of glycolytic end-product pyruvate to tricarboxylic acid cycle intermediate, oxaloacetate. Rare pyruvate carboxylase deficiency manifests in three clinical and biochemical phenotypes: neonatal onset type A, infantile onset type B and a benign C type. The objective of this case series is to expand the knowledge of overlapping clinical and biochemical phenotypes of pyruvate carboxylase deficiency. We report three Sri Lankan neonates including two siblings, of two unrelated families with pyruvate carboxylase deficiency. All three developed respiratory distress within the first few hours of birth. Two siblings displayed typical biochemical findings reported in type B. The other proband with normal citrulline, lysine, moderate lactate, paraventricular cystic lesions, bony deformities, and a novel missense, homozygous variant c.2746G>C [p.(Asp916His)] in the PC gene, biochemically favoured type A. Our findings indicate the necessity of prompt laboratory investigations in a tachypneic neonate with coexisting metabolic acidosis, as early recognition is essential for patient management and family counselling. Further case studies are required to identify overlapping symptoms and biochemical findings in different types of pyruvate carboxylase deficiency phenotypes. [ABSTRACT FROM AUTHOR]

Simple Summary: Given the escalating production of livestock and poultry, coupled with the surging cost of soybean meal, the search for alternative raw materials that can replace soybean meal is becoming more important. Agricultural by-products like rapeseed meal, cottonseed meal, and sunflower seed meal present a promising plant-based protein alternative to soybean meal in pig production. This study revealed that corn–soybean–miscellaneous meals and corn–miscellaneous meals significantly enhanced the average daily growth of pigs weighing 25–50 kg compared to a corn–soybean meal diet. These findings suggest that miscellaneous meals can effectively serve as an alternative feed ingredient to soybean meal in pig diets. This research can be helpful to further develop miscellaneous meals (rapeseed meal, cottonseed meal, and sunflower meal) as a functional alternative feed ingredient to soybean meal. The present study aims to determine the effect of miscellaneous meals (rapeseed meal, cottonseed meal, and sunflower meal) replacing soybean meal in feed on growth performance, apparent digestibility of nutrients, serum biochemical parameters, serum free amino acid content, microbiota composition and SCFAs content in growing pigs (25–50 kg). A total of 72 (Duroc × Landrace × Yorkshire) growing pigs with initial weights of 25.79 ± 0.23 kg were randomly divided into three treatments. The pigs were fed corn–soybean meal (CON), corn–soybean–miscellaneous meals (CSM), and corn–miscellaneous meals (CMM). Each treatment included six replicates with four pigs per pen (n = 24, 12 barrows and 12 gilts). Soybean meal accounted for 22.10% of the basal diet in the CON group. In the CSM group, miscellaneous meals partially replaced soybean meal with a mixture of 4.50% rapeseed meal, 3.98% cottonseed meal, and 4.50% sunflower meal. In the CMM group, miscellaneous meals entirely replaced soybean meal with a mixture of 8.50% rapeseed meal, 8.62% cottonseed meal, and 8.5% sunflower. The results showed that compared with the CON, the CSM and CMM groups significantly improved the average daily gain (ADG) of growing pigs during the 25–50 kg stage (p < 0.05) but had no effects on average daily feed intake (ADFI) and average daily feed intake/average daily gain (F/G) (p > 0.05). Moreover, the CMM group significantly reduced nutrient apparent digestibility of gross energy compared with the CON group. The serum biochemical parameters results showed that the CSM group significantly improved the contents of total protein (TP) compared with the CON group (p < 0.05). The CMM group significantly improved the contents of total protein (TP), high-density lipoprotein cholesterol (HDL-C), and low-density lipoprotein cholesterol (LDL-C) compared with the CON group in serum (p < 0.05). In comparison with the CON group, the CMM group also significantly improved lysine (Lys), threonine (Thr), valine (Val), isoleucine (Ile), leucine (Leu), phenylalanine (Phe), arginine (Arg), and citrulline (Cit) levels in serum (p < 0.05). However, the CMM group significantly decreased non-essential amino acid content glycine (Gly) in serum compared with CON (p < 0.05), while compared with the CON group, the CSM and CMM groups had no significant effects on the relative abundance, the alpha-diversity, or the beta-diversity of fecal microbiota. Moreover, compared with the CON group, the CSM group significantly increased butyric acid and valeric acid contents of short-chain fatty acids (SCFAs) in feces (p < 0.05). In contrast to the CON group, the CMM group significantly reduced the contents of SCFAs in feces, including acetic acid, propionic acid, and isobutyric acid (p < 0.05). Collectively, the results of the present study indicate that miscellaneous meals (rapeseed meal, cottonseed meal, and sunflower meal) can partially replace the soybean meal and significantly improve the growth performance of growing pigs during the 25–50 kg stage. Thus, miscellaneous meals are a suitable protein source as basal diets to replace soybean meals for 25–50 kg growing pigs. These results can be helpful to further develop miscellaneous meals as a functional alternative feed ingredient to soybean meal. [ABSTRACT FROM AUTHOR]

To investigate effects of empagliflozin on plasma amino acids in people with type 2 diabetes. In a randomized, active-controlled, open-label trial, 58 patients with type 2 diabetes were randomized to 10 mg/day empagliflozin (n = 29) or standard treatment without empagliflozin (control group, n = 29) and treated for 12 weeks. We obtained blood samples at baseline and 12 weeks and assessed the plasma amino acid profile by liquid chromatography-mass spectrometry liquid chromatography. We also calculated the Fischer ratio (the ratio of branched-chain to aromatic amino acids). In the empagliflozin group but not in the control group, plasma levels of citrulline, histidine, and α-aminobutyric acid (AABA), the Fischer ratio, and serum high-molecular weight (HMW) adiponectin increased significantly (p = 0.0099, 0.0277, 0.0318, 0.0135, and 0.0304, respectively) and plasma plasminogen activator inhibitor-1 (PAI-1) decreased significantly (p = 0.0014). In the empagliflozin group, the change in plasma citrulline was positively correlated with the changes in HMW adiponectin (r = 0.488, p = 0.0084) and the Fischer ratio (r = 0.393, p = 0.0353) but negatively correlated with the change in ferritin (r= −0.533,p = 0.0051); the change in plasma histidine was negatively correlated with the change in PAI-1 (r= –0.398, p = 0.0397) and urinary albumin creatinine ratio (r= −0.478, p = 0.0088). Empagliflozin significantly increases plasma citrulline, histidine, and AABA in people with type 2 diabetes. identifier is UMIN000025418. [ABSTRACT FROM AUTHOR]

Watermelons are one of the most important crop species, and they are enjoyed across the globe; however, the cultivation of watermelon commercial varieties in arid regions is challenging, as they are highly susceptible to water deficit. Conversely, their wild relatives and traditional landraces have shown a higher tolerance to water deficit, which makes them important study material. Therefore, this study was undertaken to evaluate the potential roles of two compatible osmolytes (citrulline and arginine) in the tolerance of local watermelon accessions to drought stress. Four commonly cultivated watermelon accessions were used in this study to evaluate their response when exposed to water deficit stress. The accessions were planted in stress boxes in the greenhouse and allowed to grow until the fourth leaf was fully open and then the water deficit stress was initiated by withholding water for a period of nine days, before rewatering for three days. Data and leaf samples were collected at three-day intervals. The common drought indicators that were assessed, like chlorophyll fluorescence, showed that Clm-08 (wild watermelon) had significantly different results when compared to the other accessions; the Fv/Fm values for days 3, 6, and 9 were significantly higher than those of the other accessions, while phiNPQ was higher in the Clm-08 with average values of 0.41 and 0.41 on days 6 and 9 of the drought stress, respectively. This suggests that the wild watermelon responded differently to drought stress when compared with the other accessions. Arginine and citrulline are important osmolytes that play an important role in stress tolerance, and the results of the current study correlate with the common physiological indicators. The expression pattern for both the biochemical and molecular analyses of the two compatible osmolytes was higher in Clm-08 in comparison with that of the other accessions. The gene expressions of the enzymes in the citrulline and arginine pathways were higher in Clm-08; Cla022915 (CPS) recorded a 6-fold increase on day 6 and Cla002611 (ASS) recorded an 11-fold increase. This suggests that citrulline and arginine play an important role in watermelon tolerance to drought stress. [ABSTRACT FROM AUTHOR]

Depression will be the disease with the highest incidence worldwide by 2030. Data indicate that postmenopausal women have a higher incidence of mood disorders, and this high vulnerability seems to be related to hormonal changes and weight gain. Although research evaluating the profile of metabolites in mood disorders is advancing, further research, maintaining consistent methodology, is necessary to reach a consensus. Therefore, the objective of the present study was to carry out an exploratory analysis of the plasma polar metabolites of pre- and postmenopausal women to explore whether the profile is affected by depression. The plasma analysis of 50 polar metabolites was carried out in a total of 67 postmenopausal women, aged between 50 and 65 years, either without depression (n = 25) or with depression symptoms (n = 42), which had spontaneous onset of menopause and were not in use of hormone replacement therapy, insulin, or antidepressants; and in 42 healthy premenopausal women (21 without depression and 21 with depression symptoms), aged between 40 and 50 years and who were not in use of contraceptives, insulin, or antidepressants. Ten metabolites were significantly affected by depression symptoms postmenopause, including adenosine (FDR = 3.778 × 10−14), guanosine (FDR = 3.001 × 10−14), proline (FDR = 1.430 × 10−6), citrulline (FDR = 0.0001), lysine (FDR = 0.0004), and carnitine (FDR = 0.0331), which were down-regulated, and dimethylglycine (FDR = 0.0022), glutathione (FDR = 0.0048), creatine (FDR = 0.0286), and methionine (FDR = 0.0484) that were up-regulated. In premenopausal women with depression, oxidized glutathione (FDR = 0.0137) was down-regulated, and dimethylglycine (FDR = 0.0406) and 4-hydroxyproline (FDR = 0.0433) were up-regulated. The present study provided new data concerning the consequences of depression on plasma polar metabolites before and after the establishment of menopause. The results demonstrated that the postmenopausal condition presented more alterations than the premenopausal period and may indicate future measures to treat the disturbances involved in both menopause and depression. [ABSTRACT FROM AUTHOR]

All forms of life are presumed to synthesize arginine from citrulline via a two-step pathway consisting of argininosuccinate synthetase and argininosuccinate lyase using citrulline, adenosine 5'-triphosphate (ATP), and aspartate as substrates. Conversion of arginine to citrulline predominantly proceeds via hydrolysis. Here, from the hyperthermophilic archaeon Thermococcus kodakarensis, we identified an enzyme which we designate "arginine synthetase". In arginine synthesis, the enzyme converts citrulline, ATP, and free ammonia to arginine, adenosine 5'-diphosphate (ADP), and phosphate. In the reverse direction, arginine synthetase conserves the energy of arginine deimination and generates ATP from ADP and phosphate while releasing ammonia. The equilibrium constant of this reaction at pH 7.0 is [Cit][ATP][NH3]/[Arg][ADP][Pi] = 10.1 ± 0.7 at 80 °C, corresponding to a ΔG°' of -6.8 ± 0.2 kJ mol-1. Growth of the gene disruption strain was compared to the host strain in medium composed of amino acids. The results suggested that arginine synthetase is necessary in providing ornithine, the precursor for proline biosynthesis, as well as in generating ATP. Growth in medium supplemented with citrulline indicated that arginine synthetase can function in the direction of arginine synthesis. The enzyme is widespread in nature, including bacteria and eukaryotes, and catalyzes a long-overlooked energy-conserving reaction in microbial amino acid metabolism. Along with ornithine transcarbamoylase and carbamate kinase, the pathway identified here is designated the arginine synthetase pathway. [ABSTRACT FROM AUTHOR]

Background: L-Arginine (Arg) is an essential amino acid and a precursor for the synthesis of vascular nitric oxide, while L-Citrulline is a non-essential amino acid substrate for increasing L-arginine. Both L-arginine and L-Citrulline in translational studies may acutely lower the blood pressure. Current meta-analysis for L-arginine or L-Citrulline interventions in blood pressure have identified significant heterogeneity. Clinical trial evidence for L-arginine or L-Citrulline in chronic blood pressure reduction in the general population requires an examination of trial designs, as not all translational studies may have influenced vascular reactivity. Our aims are to explore whether L-arginine and L-citrulline intervention trials in chronic blood pressure consider standardized end points relevant to the general adult populations. Methods: A step-wise search on clinicaltrials.gov, the U.S. Library of Medicine registry for clinical trials, was performed including the following keyword search parameters: "completed" "L-Citrulline" "L-arginine" trial", and "adults", involving "blood pressure" reduction as a primary end point in adult humans. Results: Of the forty-four completed trials, only five were included for analysis. Following the careful evaluation of trial design, we observed heterogeneity across participant inclusion criteria (population sample size, age range, sex), interventional design (dosages, duration), and primary outcomes, measured with respect to changes in diastolic or systolic blood pressure. Conclusion: In conclusion, there is a lack of robust trial design evidence to suggest that L-arginine or L-Citrulline, based on current RCTs in the general population, have an overall positive effect on vascular endothelial reactivity and a beneficial chronic blood pressure-lowering effect. Indeed, conclusions drawn from human meta-analysis studies have been heterogenous between studies, which may be attributed to study design heterogeneity, including differences in sample population, age, and blood pressure at the time of entry. Inconsistencies in the study design poses a challenge for systematic reviews and meta-analysis to accurately assess the effect size and impact of L-arginine or L-citrulline on both systolic and diastolic blood pressure. [ABSTRACT FROM AUTHOR]

Background: Altered concentrations of cerebrospinal fluid (CSF) and blood amino acids may be related to epilepsy or the severity of the seizure. In the present study, we assessed the concentrations of amino acids in CSF and plasma in neonates with refractory seizures. Methods: In this prospective cohort study, 27 neonates aged 1 to 56 days with refractory seizures were included. Blood and CSF samples were collected from each neonate within 24 hours after receiving 2nd antiseizure medications. All plasma and CSF samples were sent to the laboratory to measure amino acid concentrations. The associations between CSF and plasma amino acid levels with different variables were evaluated. Results: Except for leucine (P=0.15) and isoleucine (P=0.07), the levels of all amino acids were significantly higher in plasma than CSF. Significant associations were observed between types of seizure and plasma citrulline (P=0.008) and leucine concentrations (P=0.04). The mean of CSF glutamic acid was also statistically different among neonates with different EEG results (P=0.02). Conclusion: Our findings indicate that several plasma and CSF amino acids could be candidate biomarkers for neonatal refractory seizures. Further studies with larger sample size are to confirm our findings. [ABSTRACT FROM AUTHOR]

BackgroundArginine is a conditionally essential amino acid that is depleted in critically ill or surgical patients. In pediatric and adult patients, sepsis results in an arginine-deficient state, and the depletion of plasma arginine is associated with greater mortality. However, direct supplementation of arginine can result in the excessive production of nitric oxide (NO), which can contribute to the hypotension and macrovascular hypo-reactivity observed in septic shock. Pegylated arginine deiminase (ADI-PEG20, pegargiminase) reduces plasma arginine and generates citrulline that can be transported intracellularly to generate local arginine and NO, without resulting in hypotension, while maintaining microvascular patency. The objective of this study was to assess the efficacy of ADI-PEG20 with and without supplemental intravenous citrulline in mitigating hypovolemic shock, maintaining tissue levels of arginine, and reducing systemic inflammation in an endotoxemic pediatric pig model.MethodsTwenty 3-week-old crossbred piglets were implanted with jugular and carotid catheters as well as telemetry devices in the femoral artery to measure blood pressure, body temperature, heart rate, and respiration rate. The piglets were assigned to one of three treatments before undergoing a 5 h lipopolysaccharide (LPS) infusion protocol. Twenty-four hours before LPS infusion, control pigs (LPS; n=6) received saline, ADI-PEG20 pigs (n=7) received an injection of ADI-PEG20, and seven pigs (ADI-PEG20 + CIT pigs [n=7]) received ADI-PEG20 and 250 mg/kg citrulline intravenously. Pigs were monitored throughout LPS infusion and tissue was harvested at the end of the protocol.ResultsPlasma arginine levels decreased and remained low in ADI-PEG20 + CIT and ADI-PEG20 pigs compared with LPS pigs but tissue arginine levels in the liver and kidney were similar across all treatments. Mean arterial pressure in all groups decreased from 90 mmHg to 60 mmHg within 1 h of LPS infusion but there were no significant differences between treatment groups. ADI-PEG20 and ADI-PEG20 + CIT pigs had less CD45+ infiltrate in the liver and lung and lower levels of pro-inflammatory cytokines in the plasma.ConclusionADI-PEG20 and citrulline supplementation failed to ameliorate the hypotension associated with acute endotoxic sepsis in pigs but reduced systemic and local inflammation in the lung and liver.

The role of arginine in the development of primary arterial hypertension continues to be clarified up to the present moment. During natural metabolic processes in cells, methylated forms of arginine are produced – symmetric (SDMA) and asymmetric (ADMA) dimethylarginine. ADMA is a nitric oxide synthase inhibitor and is now considered a well-established marker for endothelial dysfunction. SDMA is not a nitric oxide synthase inhibitor, but may indirectly reduce nitric oxide production through competitive interaction with cellular L-arginine.Currently, arginine preparations are practically not used for the treatment of primary arterial hypertension. This was the rationale for the given scientific review. The article summarizes the information available in the literature (2018–2022) on the pathogenetic mechanisms of the relationship between arginine and the development of impaired vascular tone. We used PubMed and RSCI databases for our review. Using keywords, 1784 publications were found over the past 5 years. The final selection criteria were time frame and matching keywords. The review provides data on the increased ADMA concentrations in experimental hypertensive animals and individuals with essential hypertension. The role of arginine metabolites in the genesis of endothelial dysfunction and arterial hypertension and the prospects for the therapeutic use of this compound are discussed.

BackgroundIonizing radiation can cause damage to animal's intestinal tissue. Citrulline is produced in the intestinal epithelial cell and has been proven to possess a protective effect on the gastrointestinal tract.PurposeThis study aims to investigate the protective effects and the underlying mechanisms of citrulline in the context of radiation-induced intestinal injuries.MethodsFirstly, a mouse model of an acute radiation-induced intestinal injury was established, incorporating a normal control, a simple irradiation, and an irradiation plus citrulline group. Then, these groups were employed to scrutinize the protective effects and mechanisms associated with citrulline. Subsequently, hematoxylin-eosin staining was used to examine the morphology of the mice's intestinal tissue, and the Elisa kit was employed to quantify endotoxin levels in plasma, as well as nitric oxide and inducible nitric oxide synthase in the intestinal tissue. Finally, focal adhesion kinase and Occludin levels in the intestinal tissue were assessed using western blotting.ResultsThe experimental results demonstrate that intraperitoneal injection of 1 g∙kg-1∙d-1 citrulline for one week following irradiation significantly extend the median survival time of irradiated mice and increase their body weight. Moreover, it markedly reduces plasma endotoxin levels, elevate the expression levels of focal adhesion kinase (FAK) and intestinal tight junction protein (Occludin), and decreases the expression levels of nitric oxide (NO) and inducible nitric oxide synthase (iNOS) in the intestinal tissue.ConclusionsCitrulline enhances the integrity of the intestinal barrier in irradiated mice, improves barrier function, mitigates nitrosative stress, and demonstrates a protective impact on radiation-induced intestinal damage in mice.

Introduction: Jinteng Qingbi granules (JTQBG), a traditional Chinese medicine formulation, are widely used for the treatment of rheumatoid arthritis (RA) due to their satisfactory therapeutic efficacy. However, the underlying mechanism of action remains unclear. This study aims to investigate the protective effects of JTQBG against RA and elucidates its potential molecular mechanisms. Methods: A collagen-induced arthritis (CIA) rat model was utilized, and JTQBG (1.25, 2.5, 5 g/kg/day) or methotrexate (MTX, 1 mg/kg/week) was orally administered. The rats' weight, arthritis index (AI), and paw volume were measured weekly. Synovial hyperplasia of the joints was detected using a small animal ultrasound imaging system. Joint destruction was assessed using an X-ray imaging system. Histopathological examinations were performed using hematoxylin-eosin (H&E), Saffron-O and fast green staining. Serum inflammatory cytokines were detected using ELISA. Furthermore, 4D label-free quantitative proteomics of synovial tissues and non-targeted metabolomics of blood serum were conducted to analyze the molecular mechanisms. Results: JTQBG exerted a significant therapeutic effect on CIA rats by reducing inflammatory cell infiltration, synovial hyperplasia, cartilage erosion, and bone destruction. It also decreased the spleen index, inhibited hyperplasia of the white pulp, and decreased the serum levels of IL-1β and IL-18. Proteomics analysis identified 367 differentially expressed proteins (DEPs) between the Model and Normal groups, and 71 DEPs between the JTQBG and Model groups. These DEPs were significantly enriched in the NF-κB pathway. 11 DEPs were significantly reversed after treatment with JTQBG. Western blot results further validated the expression levels of Nfkb1, Pdk1, and Pecam1, and analyzed the expression levels of p-IKK, p-IκBa, and IκBa. The therapeutic efficacy of JTQBG was partly attributed to the suppression of the NF-κB pathway in synovial tissues. Serum metabolomics identified 17 potential biomarkers for JTQBG treatment of CIA rats, which were closely related to Alanine, aspartate and glutamate metabolism, Tryptophan metabolism, Ascorbate and aldarate metabolism, Arginine metabolism, and Inositol phosphate metabolism. Conclusion: Our findings demonstrated that JTQBG was effective against RA by alleviating synovial inflammation, synovial hyperplasia, and joint destruction. The anti-RA properties of JTQBG were likely attributed to the inhibition of the NF-κB pathway and the regulation of serum metabolite disorders. [ABSTRACT FROM AUTHOR]

Simple Summary: There is evidence of the influence of the intestinal microbiota on the response to immunotherapy in cancer. In addition, we lack markers of response to treatment and toxicity, which obliges us to continue our search for them. In this work, we recruited patients with non-small-cell lung cancer receiving immunotherapy who contributed a fecal and blood sample. We analyzed the possible relationship between the response to immune checkpoint inhibitors and the occurrence of immune-related adverse events, the composition (16S rDNA amplification) and functionality (abundance of short-chain fatty acids) of the gut microbiota, and intestinal membrane permeability as a human factor. No correlations were detected between analytical markers and clinical evolution, with a marked individuality of the gut microbiota in terms of composition, but homogeneity in its functionality and permeability. Immune checkpoint inhibitors have been proposed as the standard treatment for different stages of non-small-cell lung cancer in multiple indications. Not all patients benefit from these treatments, however, and certain patients develop immune-related adverse events. Although the search for predictors of response to these drugs is a major field of research, these issues have yet to be resolved. It has been postulated that microbiota could play a relevant role in conditioning the response to cancer treatments; however, the human factor of intestinal permeability also needs to be considered as it is closely related to the regulation of host–microbiota interaction. In this article, we analyzed the possible relationship between the response to immune checkpoint inhibitors and the onset of immune-related adverse events, gut microbiota status, and intestinal membrane permeability. In a pioneering step, we also measured short-chain fatty acid content in feces. Although the correlation analyses failed to identify predictive biomarkers, even when all variables were integrated, our patients' microbial gut ecosystems were rich and diverse, and the intestinal barrier's integrity was preserved. These results add new knowledge on the composition of microbiota and its correlation with barrier permeability and short-chain fatty acids and suggest that more studies are required before these potential biomarkers can be incorporated into the clinical management of patients via immune checkpoint inhibitor treatment. [ABSTRACT FROM AUTHOR]

Despite its efficacy for treating androgenetic alopecia, finasteride, an inhibitor of 5α‐reductase (i.e., the enzyme converting testosterone, T, into dihydrotestosterone, DHT), is associated with several side effects including sexual dysfunction (e.g., erectile dysfunction). These side effects may persist after drug suspension, inducing the so‐called post‐finasteride syndrome (PFS). The effects of subchronic treatment with finasteride (i.e., 20 days) and its withdrawal (i.e., 1 month) in rat corpus cavernosum have been explored here. Data obtained show that the treatment was able to decrease the levels of the enzyme 5α‐reductase type II in the rat corpus cavernosum with increased T and decreased DHT levels. This local change in T metabolism was linked to mechanisms associated with erectile dysfunction. Indeed, by targeted metabolomics, we reported a decrease in the nitric oxide synthase (NOS) activity, measured by the citrulline/arginine ratio and confirmed by the decrease in NO2 levels, and a decrease in ornithine transcarbamylase (OTC) activity, measured by citrulline/ornithine ratio. Interestingly, the T levels are negatively correlated with NOS activity, while those of DHT are positively correlated with OTC activity. Finasteride treatment also induced alterations in the levels of other molecules involved in the control of penile erection, such as norepinephrine and its metabolite, epinephrine. Indeed, plasma levels of norepinephrine and epinephrine were significantly increased and decreased, respectively, suggesting an impairment of these mediators. Interestingly, these modifications were restored by suspension of the drug. Altogether, the results reported here indicate that finasteride treatment, but not its withdrawal, affects T metabolism in the rat corpus cavernosum, and this alteration was linked to mechanisms associated with erectile dysfunction. Data here reported could also suggest that the PFS sexual side effects are more related to dysfunction in a sexual central control rather than peripheral compromised condition. [ABSTRACT FROM AUTHOR]

Cyanobacteria are among the oldest organisms colonizing Earth. Their great biodiversity and ability to biosynthesize secondary metabolites through a variety of routes makes them attractive resources for biotechnological applications and drug discovery. In this pioneer study, four filamentous cyanobacteria (Cephalothrix lacustris LEGE 15493, Leptolyngbya boryana LEGE 15486, Nodosilinea nodulosa LEGE 06104 and Leptothoe sp. LEGE 11479) were explored for their anti-inflammatory potential in cell and cell-free in vitro bioassays, involving different inflammatory mediators and enzymes. Extracts of different polarities were sequentially prepared and chemically characterized for their content of phycobiliproteins (PBPs) and carotenoids. HPLC-PDA analysis of the acetone extracts revealed β-carotene to be the dominant carotenoid (18.4–44.3 mg/g) and zeaxanthin as the dominant xanthophyll (52.7–192.9 mg/g), with Leptothoe sp. LEGE 11479 and Nodosilinea nodulosa LEGE 06104, respectively, being the richest strains. The PBP profile was in accordance with the color presented by the aqueous extracts, with Leptolyngbya boryana LEGE 15486 being the richest in phycocyanin (204.5 μg/mg) and Leptothoe sp. LEGE 11479 the richest in phycoerythrin (78.5 μg/mg). Aqueous extracts were more effective in superoxide anion radical scavenging, while acetone ones were more effective in scavenging nitric oxide radical (●NO) and in inhibiting lipoxygenase. Acetone extracts also reduced ●NO production in lipopolysaccharide-stimulated RAW 264.7 macrophages, with the mechanistic study suggesting a downregulation of the inducible nitric oxide synthase expression. Nodosilinea nodulosa LEGE 06104 and Leptothoe sp. LEGE 11479 acetone extracts presented the lowest IC50 values for the mentioned assays, pointing them out as promising resources for the development of new multi-target anti-inflammatory therapies. [ABSTRACT FROM AUTHOR]

Carbamoyl phosphate synthetase 1 (CPS1) and ornithine transcarbamylase (OTC) deficiencies are rare urea cycle disorders, which can lead to life‐threatening hyperammonemia. Liver transplantation (LT) provides a cure and offers an alternative to medical treatment and life‐long dietary restrictions with permanent impending risk of hyperammonemia. Nevertheless, in most patients, metabolic aberrations persist after LT, especially low plasma citrulline levels, with questionable clinical impact. So far, little is known about these alterations and there is no consensus, whether l‐citrulline substitution after LT improves patients' symptoms and outcomes. In this multicentre, retrospective, observational study of 24 patients who underwent LT for CPS1 (n = 11) or OTC (n = 13) deficiency, 25% did not receive l‐citrulline or arginine substitution. Correlation analysis revealed no correlation between substitution dosage and citrulline levels (CPS1, p = 0.8 and OTC, p = 1). Arginine levels after liver transplantation were normal after LT independent of citrulline substitution. Native liver survival had no impact on mental impairment (p = 0.67). Regression analysis showed no correlation between l‐citrulline substitution and failure to thrive (p = 0.611) or neurological outcome (p = 0.701). Peak ammonia had a significant effect on mental impairment (p = 0.017). Peak plasma ammonia levels correlate with mental impairment after LT in CPS1 and OTC deficiency. Growth and intellectual impairment after LT are not significantly associated with l‐citrulline substitution. [ABSTRACT FROM AUTHOR]

The MT‐TL2 m.12315G>A pathogenic variant has previously been reported in five individuals with mild clinical phenotypes. Herein we report the case of a 5‐year‐old child with heteroplasmy for this variant who developed neurological regression and stroke‐like episodes similar to those observed in mitochondrial encephalopathy, lactic acidosis, and stroke‐like episodes (MELAS). Biochemical evaluation revealed depletion of arginine on plasma amino acid analysis and low z‐scores for citrulline on untargeted plasma metabolomics analysis. These findings suggested that decreased availability of nitric oxide may have contributed to the stroke‐like episodes. The use of intravenous arginine during stroke‐like episodes and daily enteral L‐citrulline supplementation normalized her biochemical values of arginine and citrulline. Untargeted plasma metabolomics showed the absence of nicotinamide and 1‐methylnicotinamide, and plasma total glutathione levels were low; thus, nicotinamide riboside and N‐acetylcysteine therapies were initiated. This report expands the phenotype associated with the rare mitochondrial variant MT‐TL2 m.12315G>A to include neurological regression and a MELAS‐like phenotype. Individuals with this variant should undergo in‐depth biochemical analysis to include untargeted plasma metabolomics, plasma amino acids, and glutathione levels to help guide a targeted approach to treatment. [ABSTRACT FROM AUTHOR]

This article, titled "Low Arginine Suggesting the Diagnosis of Mitochondrial Cardiomyopathy," discusses the case of an 11-month-old male with developmental delay and failure to thrive who presented with severe dilated cardiomyopathy. The patient exhibited dysmorphic features and metabolic evaluation revealed low arginine levels, suggesting a mitochondrial disorder, specifically Barth syndrome. Further testing confirmed the diagnosis and treatment options, including arginine supplementation and elamipretide, were discussed. The article emphasizes the importance of early diagnosis and metabolic evaluation in patients with cardiomyopathies and highlights the characteristic features and biochemical abnormalities associated with Barth syndrome. [Extracted from the article]

Early enteral nutrition using reliable biomarkers of intestinal function must be established to improve neurodevelopmental outcomes in very low birth weight infants (VLBWIs). Serum citrulline levels reflect the intestinal function in adults. To elucidate the relationship among antenatal growth, postnatal enteral nutrition, and blood citrulline levels, a retrospective single-center observational study was conducted on 248 VLBWIs born between April 2014 and March 2021. A mixed effect model and post hoc simple slope analysis were used to estimate the correlations between clinical variables and citrulline levels at Early (day 5.1) and Late (day 24.3) postnatal ages. Greater gestational age, birth weight, and amount of enteral nutrition at the time of blood sampling were associated with lower citrulline levels at the Early postnatal age and higher citrulline levels at the Late postnatal age. Provided that Early citrulline levels predominantly reflect the consequence of antenatal citrulline metabolism, it is suggested that fetal growth and maturation are likely to promote citrulline catabolism in utero and its synthesis after birth. With additional insights into the temporal transition point wherein the maturation-dependent balance of citrulline metabolism shifts from catabolism-dominant to synthesis-dominant, citrulline emerges as a potential biomarker for assessing intestinal function and gastrointestinal disorders. [ABSTRACT FROM AUTHOR]

Introduction: Intestinal ischemia and reperfusion (IIR) injury is closely associated with oxidative stress. Evidence shows that oral supplementation with glutamine and citrulline alleviates IIR-induced jejunal damage. We investigated the effects of a combination of glutamine, citrulline, and antioxidant vitamins on IIR-induced jejunal damage, oxidative stress, and inflammation. Method: Male Wistar rats that underwent 60 min of superior mesenteric artery occlusion were orally administered glutamine plus citrulline (GC), vitamin C plus E (CE), or a combination of GC and CE 15 min before and 3, 9, and 21 h after reperfusion. Healthy rats without IIR were used as controls. Results: After reperfusion for 24 h, rats with IIR showed lower levels of red blood cells, hemoglobin, serum glucose, and jejunal DNA and increased white blood cell counts compared to controls (1-way ANOVA with the least significant difference, P < 0.05). The IIR-induced decrease in serum albumin and increase in plasma interleukin-6 and jejunal thiobarbituric acid-reactive substances (TBARS) were significantly reversed by GC and/or CE. The results of the 2-way ANOVA indicated that GC was the main factor that increased jejunal villus height and muscularis DNA, and CE was the main factor that increased jejunal muscularis protein and decreased jejunal proinflammatory cytokine levels and myeloperoxidase activity. In addition, GC and CE are the main factors that decrease plasma proinflammatory cytokine levels and the jejunal apoptotic index. Conclusion: Oral post-treatment supplementation with glutamine and citrulline, combined with vitamins C and E, may alleviate IIR-induced oxidative stress, inflammation, and jejunal damage. [ABSTRACT FROM AUTHOR]

The urea cycle has been found to be closely associated with certain types of cancers and other diseases such as cardiovascular disease and chronic kidney disease. An analytical method for the precise quantification of urea cycle amino acids (arginine, ornithine, citrulline, and argininosuccinate) by off-line two-dimensional liquid chromatography (2D-LC) combined with fluorescence-based detection was developed. Before analysis, the amino acids were derivatised with 4-fluoro-7-nitro-2,1,3-benzoxadiazole (NBD-F) to obtain NBD-amino acids. The first dimension involved the reversed-phase separation, in which NBD derivatives of urea cycle amino acids were completely separated from each other and mostly separated from the 18 NBD-proteinogenic amino acids. The samples were eluted with stepwise gradient using 0.02% trifluoroacetic acid in water–acetonitrile as the mobile phase. In the second dimension, an amino column was used for the separation of NBD-ornithine, -citrulline, and -argininosuccinate, while a sulfonic acid column was used to separate NBD-arginine. The developed 2D-LC system was used to analyse human plasma samples. The fractions of NBD-urea cycle amino acids obtained in the first dimension were collected manually and introduced into the second dimension. By choosing appropriate mobile phases for the second dimension, each NBD-urea cycle amino acid eluted in the first dimension was well separated from the other proteinogenic amino acids and interference from endogenous substance. This could not be achieved in the first dimension. The urea cycle amino acids in human plasma sample were quantified, and the method was well validated. The calibration curves for each NBD-urea cycle amino acid showed good linearity from 3 (ASA) or 15 (Orn, Cit, and Arg) to 600 nM, with correlation coefficients higher than 0.9969. The intraday and interday precisions were less than 7.9% and 15%, respectively. The 2D-LC system is expected to be useful for understanding the involvement of the urea cycle in disease progression. [ABSTRACT FROM AUTHOR]

Simple Summary: The gut microbiota plays an active role in gut development and host growth in juvenile ruminants and contributes to their productive performance in adulthood. However, the gut microbiota composition and metabolic profile patterns of succession from birth to weaning of juvenile sika deer remain unclear. Feces are a highly efficient and convenient biological sample that can be used to reflect gut microbiology and metabolomics studies. Based on fecal samples, we demonstrated that the gut bacterial community and metabolic profile of juvenile sika deer were significantly altered at birth compared to the transition and rumination periods, suggesting functional changes in amino acid metabolism and carbohydrate metabolism. Our results revealed the key role of the birth–transition period in the regulation of gut bacterial communities and metabolic functions during juvenile sika deer development. The gut microbiota establishment in young ruminants has a profound impact on their adult production performance. However, the critical phase for the succession of the gut microbial composition and metabolic profiles of juvenile sika deer still needs to be further investigated. Here, we analyzed the fecal microbiota and metabolites of juvenile sika deer during the birth (D1), transition (D42), and rumination (D70) periods based on 16S rRNA sequencing and gas chromatography–time–of–flight mass spectrometry (GC–TOF–MS). The results showed that the fecal bacteria and metabolites composition were significantly different in D1 compared to D42 and D70, and the number of OTUs and the Shannon index were significantly higher in D70 than in D1 (p < 0.05). The relative abundances of Lactobacillus, Lactococcus, and Lachnoclostridium showed a significant increase in D1 compared to D42 and D70, whereas the relative abundances of Ruminococcaceae UCG-005, Ruminococcaceae UCG-010, Ruminococcaceae UCG-014, Christensenellaceae R-7, and Eubacterium coprostanoligenes group were significantly decreased in D1 compared to D42 and D70 (p < 0.05). The amounts of serine, phenylalanine, aspartic acid, ornithine, citrulline, creatine, isoleucine, galactose, and ribose in the feces were significantly higher in D1 compared to D42 and D70. In contrast, the concentrations of cortexolone, resveratrol, piceatannol, fumaric acid, alpha-ketoglutarate, glycerol, uracil-5-carboxylic acid, and maleic acid were significantly decreased in D1. The enrichment analysis showed that amino acid metabolism and carbohydrate metabolism were significantly changed in D1 compared to D42 and D70. The glycine, serine and threonine metabolism; alanine, aspartate and glutamate metabolism; arginine biosynthesis; glyoxylate and dicarboxylate metabolism; citrate cycle; and pyruvate metabolism were significantly enriched across the three periods (p < 0.05). In conclusion, our results suggested that the birth–transition period is a critical phase for the gut bacterial community and metabolic function shift in juvenile sika deer. [ABSTRACT FROM AUTHOR]

The growing recognition of the association between maternal chronic kidney disease (CKD) and fetal programming highlights the increased vulnerability of hypertension in offspring. Potential mechanisms involve oxidative stress, dysbiosis in gut microbiota, and activation of the renin–angiotensin system (RAS). Our prior investigation showed that the administration of adenine to pregnant rats resulted in the development of CKD, ultimately causing hypertension in their adult offspring. Citrulline, known for enhancing nitric oxide (NO) production and possessing antioxidant and antihypertensive properties, was explored for its potential to reverse high blood pressure (BP) in offspring born to CKD dams. Male rat offspring, both from normal and adenine-induced CKD models, were randomly assigned to four groups (8 animals each): (1) control, (2) CKD, (3) citrulline-treated control rats, and (4) citrulline-treated CKD rats. Citrulline supplementation successfully reversed elevated BP in male progeny born to uremic mothers. The protective effects of perinatal citrulline supplementation were linked to an enhanced NO pathway, decreased expression of renal (pro)renin receptor, and changes in gut microbiota composition. Citrulline supplementation led to a reduction in the abundance of Monoglobus and Streptococcus genera and an increase in Agothobacterium Butyriciproducens. Citrulline's ability to influence taxa associated with hypertension may be linked to its protective effects against maternal CKD-induced offspring hypertension. In conclusion, perinatal citrulline treatment increased NO availability and mitigated elevated BP in rat offspring from uremic mother rats. [ABSTRACT FROM AUTHOR]

Oral supplementation with L-citrulline, which is sequentially converted to L-arginine then nitric oxide, improves vascular biomarkers and reduces blood pressure in non-pregnant, hypertensive human cohorts and pregnant mice with a pre-eclampsia-like syndrome. This early-phase randomised feasibility trial assessed the acceptability of L-citrulline supplementation to pregnant women with chronic hypertension and its effects on maternal BP and other vascular outcomes. Pregnant women with chronic hypertension were randomised at 12–16 weeks to receive 3-g L-citrulline twice daily (n = 24) or placebo (n = 12) for 8 weeks. Pregnant women reported high acceptability of oral L-citrulline. Treatment increased maternal plasma levels of citrulline, arginine and the arginine:asymmetric dimethylarginine ratio, particularly in women reporting good compliance. L-citrulline had no effect on diastolic BP (L-citrulline: − 1.82 95% CI (− 5.86, 2.22) vs placebo: − 5.00 95% CI (− 12.76, 2.76)), uterine artery Doppler or angiogenic biomarkers. Although there was no effect on BP, retrospectively, this study was underpowered to detect BP changes < 9 mmHg, limiting the conclusions about biological effects. The increase in arginine:asymmetric dimethylarginine ratio was less than in non-pregnant populations, which likely reflects altered pharmacokinetics of pregnancy, and further pharmacokinetic assessment of L-citrulline in pregnancy is advised. Trial Registration EudraCT 2015-005792-25 (2017-12-22) and ISRCTN12695929 (2018-09-20) In pregnant women with chronic hypertension, L-citrulline is an acceptable intervention which increased plasma L-citrulline bioavailability but did not affect BP, potentially due to altered pharmacokinetics of pregnancy. [ABSTRACT FROM AUTHOR]

Tetrahydrobiopterin deficiency in newborns with atypical hyperphenylalaninemia requires rapid and accurate diagnosis and the ability to distinguish it from the classical type to prevent early irreversible neurological damage. The study aimed to evaluate neopterin and biopterin (products of tetrahydrobiopterin recycling pathway) and amino acid profiles (used in supplementation therapy) in patients with hyperphenylalaninemia after optimizing ultra-performance liquid chromatography coupled with tandem mass spectrometry to simultaneously measure neopterin, biopterin, and amino acids in dried blood spots. The study enrolled preselected infants with classic (n = 46), atypical (n = 14) hyperphenylalaninemia, and a control group (n = 50). Result Tandem mass spectrometry detected neo/biopterin in the blood with a sensitivity and specificity of 100%. The mean neo/biopterin levels were significantly lower in the atypical cases (4 ± 1 and 3 ± 1 nmol/L) than the classic (49 ± 13 and 50 ± 12 nmol/L) and control (15.2 and 15.3 nmol/L) groups and correlated with phenylalanine and phenylalanine to tyrosine ratio (all P < 0.05). The study compared classic and atypical hyperphenylalaninemia cases with the control group. Both classic and atypical cases exhibited decreased levels of arginine, valine, and leucine compared to controls. Classic cases showed increased levels of citrulline, ornithine, and methionine, while atypical cases showed increased citrulline levels only. Comparing atypical versus classic cases, atypical cases exhibited decreased levels of citrulline, ornithine, methionine, arginine, leucine, and valine (all P < 0.05). Correlation analysis revealed negative associations between ornithine and biopterin and between arginine and neopterin in classic PKU cases. These findings highlight distinct metabolic differences between classic and atypical PKU. Conclusion The optimized method detected neo/biopterin in the blood with accuracy and precision. The characteristic pattern of neo/biopterin in the blood makes it possible to differentiate between classic and atypical hyperphenylalaninemia with a sensitivity and specificity of 100%. The amino acid profile could add value when treatment with large neutral amino acids is considered. [ABSTRACT FROM AUTHOR]

By affecting the ovarian pool of follicles and their enclosed oocytes, heat stress has an impact on dairy cow fertility. This study aimed to determine how heat shock (HS) during in vitro maturation affected the ability of the bovine cumulus-oocyte complexes (COCs) to develop, as well as their metabolism of amino acids (AAs). In this study, COCs were in vitro matured for 23 h at 38.5 °C (control; n = 322), 39.5 °C (mild HS (MHS); n = 290), or 40.5 °C (severe HS (SHS); n = 245). In comparison to the control group, the MHS and SHS groups significantly decreased the percentage of metaphase-II oocytes, as well as cumulus cell expansion and viability. The SHS decreased the rates of cleavage and blastocyst formation in comparison to the control and MHS. Compared to the control and MHS-COCs, the SHS-COCs produced significantly more phenylalanine, threonine, valine, arginine, alanine, glutamic acid, and citrulline while depleting less leucine, glutamine, and serine. Data showed that SHS-COCs had the highest appearance and turnover of all AAs and essential AAs. Heat shock was positively correlated with the appearance of glutamic acid, glutamine, isoleucine, alanine, serine, valine, phenylalanine, and asparagine. Network analysis identified the relationship between HS and alanine or glutamic acid, as well as the relationship between blastocyst and cleavage rates and ornithine. The findings imply that SHS may have an impact on the quality and metabolism of AAs in COCs. Moreover, the use of a multistep analysis could simply identify the AAs most closely linked to HS and the developmental competence of bovine COCs. [ABSTRACT FROM AUTHOR]

Arginine deiminase (ADI) has been widely employed for the biological production of nutraceutical citrulline. However, sub-optimal enzyme properties, operational instability, and difficulty in reuse impede its industrial usage as well as increase the production cost. The present study describes a simple, cost-effective carrier-free immobilization technology that can circumvent these limitations. ADI was precipitated and cross-linked with glutaraldehyde to obtain novel cross-linked arginine deiminase aggregates (ADI-CLEA). A neural network-based multiobjective genetic algorithm (MOGA-NN) was employed to optimize the immobilization of ADI. MOGA-NN optimization yielded ADI-CLEA with 0.30 IU/mL activity and 61 % recovery. Structural characterization using TEM, SEM, FTIR, DLS/ZETA revealed that the developed ADI-CLEA were monodisperse, ultra-porous, and highly stable. ADI-CLEA showed an improved pH /temperature profile and resistivity against denaturants than free enzyme. The efficiency of ADI-CLEA in the industrial production of nutraceutical citrulline was also studied. ADI-CLEA produced 215.4 g/L citrulline in first cycle of usage. Reusability and storage stability analysis further showed that ADI-CLEA could be reused for more than seven consecutive cycles and stable for up to 50 days. In conclusion, this novel formulation increases the stability/robustness of ADI, eases the product separation process and could be reused for economically viable bioproduction of nutraceutical citrulline in industries. [Display omitted] • Novel cross-linked enzyme aggregates of arginine deiminase (ADI-CLEA) were reported. • Immobilization conditions were optimized by network-based multiobjective genetic algorithm. • ADI-CLEA exhibited enhanced catalytic efficiency, stability and robustness. • Improved citrulline yield (215 g/L) was obtained by ADI-CLEA. • ADI-CLEA could be recycled for seven cycles without losing its activity. [ABSTRACT FROM AUTHOR]

Giriş ve Amaç: Tiroid fonksiyon bozukluğu, Hashimoto tiroiditi (HT) hastalarında kardiyovasküler hastalık (KVH) riskini artırdığı bilinmektedir. Ancak henüz tiroid fonksiyon bozukluğu gelişmemiş ötiroid HT hastalarında KVH riski ile ilgili veriler yetersizdir. Biz çalışmamızda asimetrik dimetilarjinin (ADMA), simetrik dimetil arjinin (SDMA), N-monometil-L-arjinin (L-NMMA), Arginine and Citrulline düzeylerinin bu riskin erken belirteçleri olarak kullanılıp kullanılamayacağını araştırmayı amaçladık. Gereç ve Yöntemler: Tiroid antikor pozitifliği ve ultrasonografik bulgularla HT tanısı alan, tiroid fonksiyon bozukluğu olmayan 65 pubertal kadın hasta ve 70 sağlıklı kontrol çalışmamıza dahil edildi. Gruplar arasında kan basıncı düzeyleri, tiroid fonksiyon testi verileri, tiroid antikor düzeyleri ve inflamatuar parametreler ile ADMA, SDMA, L-NMMA, Arjinin ve Sitrüllin düzeyleri karşılaştırıldı ve ADMA, SDMA, L-NMMA, Arjinin ve Sitrüllin düzeylerinin diğer KVH belirteçleriyle ilişkileri belirlendi. Bulgular : Hasta grubunda TSH, anti-TPO, anti-Tg ve ADMA değerleri yüksek saptanırken; sitrülin, arjinin ve arjinin/ADMA değerleri düşük olarak saptandı. Hasta grubunda ADMA ile SDMA, L-NMMA, sT3, total kolesterol, LDL, trigliserit, bel çevresi/kalça çevresi ve VKİ SSS değerleri arasında anlamlı pozitif korelasyon gözlenirken, arjinin/ADMA değerleri ile anlamlı negatif korelasyon saptandı. Sonuç: Çalışmamızda ötiroid Hashimoto tiroiditli hastalarda; erken dönemde, ADMA düzeylerinde artış saptandı. ADMA’nın antropometrik ölçümler, metabolik parametreler, SDMA ve L-NMMA ile olan ilişkileri nedeni ile ötiroid HT’li hastalarda KVH risk belirteci olarak kullanılabilir. Ancak daha büyük örneklem büyüklüğüne sahip ileri çalışmalara ihtiyaç vardır.

Scientific relevance. A key anti-ischaemic mechanism of some medicinal products involves their effects on the metabolism of endothelial vasodilators, particularly the synthesis of nitric oxide from arginine and its precursor citrulline.Aim. The study was aimed to determine whether the plasma time course of guanidine derivatives (arginine precursors) is applicable to laboratory control of anti-ischaemic therapy effectiveness using a single oral dose of nicorandil in patients with coronary heart disease as a case study.Materials and methods. The authors used high-performance liquid chromatography to determine metabolites. Blood samples for analysis were obtained from 30 patients with angina pectoris (Grade II–III, Canadian Cardiovascular Society) and 30 healthy donors. All the study participants received a single oral dose of 20 mg nicorandil after 10 h of fasting.Results. At baseline, patients showed significantly higher plasma citrulline levels than donors. However, the elevated levels decreased to the healthy range after nicorandil administration. Plasma arginine levels in patients showed a statistically significant increase following nicorandil administration. Plasma homoarginine levels in patients remained reduced both before and after dosing. Nicorandil did not influence elevated levels of the endogenous nitric oxide synthase inhibitor (asymmetrical dimethylarginine).Conclusions. In addition to the established mechanisms responsible for altering cell metabolism, nicorandil enhances the contribution of citrulline to arginine resynthesis. It is reasonable to include citrulline and arginine, which are involved in the vasodilator response, in model schemes for laboratory control of the effectiveness of anti-ischaemic therapy.

This study investigated the correlation between oxidative stress and blood amino acids associated with nitric oxide metabolism in adult patients with coronavirus disease (COVID-19) pneumonia. Clinical data and serum samples were prospectively collected from 100 adult patients hospitalized for COVID-19 between July 2020 and August 2021. Patients with COVID-19 were categorized into three groups for analysis based on lung infiltrates, oxygen inhalation upon admission, and the initiation of oxygen therapy after admission. Blood data, oxidative stress-related biomarkers, and serum amino acid levels upon admission were compared in these groups. Patients with lung infiltrations requiring oxygen therapy upon admission or starting oxygen post-admission exhibited higher serum levels of hydroperoxides and lower levels of citrulline compared to the control group. No remarkable differences were observed in nitrite/nitrate, asymmetric dimethylarginine, and arginine levels. Serum citrulline levels correlated significantly with serum lactate dehydrogenase and C-reactive protein levels. A significant negative correlation was found between serum levels of citrulline and hydroperoxides. Levels of hydroperoxides decreased, and citrulline levels increased during the recovery period compared to admission. Patients with COVID-19 with extensive pneumonia or poor oxygenation showed increased oxidative stress and reduced citrulline levels in the blood compared to those with fewer pulmonary complications. These findings suggest that combined oxidative stress and abnormal citrulline metabolism may play a role in the pathogenesis of COVID-19 pneumonia.