Invasive pulmonary aspergillosis (IPA) is a fatal fungal infection with a high mortality rate. Voriconazole (VCZ) is considered a first-line therapy for IPA and shows efficacy in patients for whom other antifungal treatments have been unsuccessful. The objective of this study was to develop a high-potency VCZ-loaded liposomal system in the form of a dry-powder inhaler (DPI) using the spray-drying technique to convert liposomes into a nanocomposite microparticle (NCMP) DPI, formulated using a thin-film hydration technique. The physicochemical properties, including size, morphology, entrapment efficiency, and loading efficiency, of the formulated liposomes were evaluated. The NCMPs were then examined to determine their drug content, production yield, and aerodynamic size. The L3NCMP was formulated using a 1:1 lipid/L-leucine ratio and was selected for in vitro studies of cell viability, antifungal activity, and stability. These formulated inhalable particles offer a promising approach to the effective management of IPA.

Dry-powder inhalers (DPIs) are valued for their stability but formulating them is challenging due to powder aggregation and limited flowability, which affects drug delivery and uniformity. In this study, the incorporation of L-leucine (LEU) into hot-melt extrusion (HME) was proposed to enhance dispersibility while simultaneously maintaining the high aerodynamic performance of inhalable microparticles. This study explored using LEU in HME to improve dispersibility and maintain the high aerodynamic performance of inhalable microparticles. Formulations with crystalline itraconazole (ITZ) and LEU were made via co-jet milling and HME followed by jet milling. The LEU ratio varied, comparing solubility, homogenization, and aerodynamic performance enhancements. In HME, ITZ solubility increased, and crystallinity decreased. Higher LEU ratios in HME formulations reduced the contact angle, enhancing mass median aerodynamic diameter (MMAD) size and aerodynamic performance synergistically. Achieving a maximum extra fine particle fraction of 33.68 ± 1.31% enabled stable deep lung delivery. This study shows that HME combined with LEU effectively produces inhalable particles, which is promising for improved drug dispersion and delivery.

Both latent and multidrug-resistant tuberculosis (TB) have been causing significant concern worldwide. A novel drug, pretomanid (PA-824), has shown a potent bactericidal effect against both active and latent forms of Mycobacterium tuberculosis (MTb) and a synergistic effect when combined with pyrazinamide and moxifloxacin. This study aimed to develop triple combination spray dried inhalable formulations composed of antitubercular drugs, pretomanid, moxifloxacin, and pyrazinamide (1:2:8 w/w/w), alone (PaMP) and in combination with an aerosolization enhancer, L-leucine (20 % w/w, PaMPL). The formulation PaMPL consisted of hollow, spherical, dimpled particles (<5 μm) and showed good aerosolization behaviour with a fine particle fraction of 70 %. Solid-state characterization of formulations with and without L-leucine confirmed the amorphous nature of moxifloxacin and pretomanid and the crystalline nature of pyrazinamide with polymorphic transformation after the spray drying process. Further, the X-ray photoelectron spectroscopic analysis revealed the predominant surface composition of L-leucine on PaMPL dry powder particles. The dose-response cytotoxicity results showed pyrazinamide and moxifloxacin were non-toxic in both A549 and Calu-3 cell lines up to 150 µg/mL. However, the cell viability gradually decreased to 50 % when the pretomanid concentration increased to 150 µg/mL. The in vitro efficacy studies demonstrated that the triple combination formulation had more prominent antibacterial activity with a minimum inhibitory concentration (MIC) of 1 µg/mL against the MTb H37Rv strain as compared to individual drugs. In conclusion, the triple combination of pretomanid, moxifloxacin, and pyrazinamide as an inhalable dry powder formulation will potentially improve treatment efficacy with fewer systemic side effects in patients suffering from latent and multidrug-resistant TB.

The extract of mulberry leaf and its active ingredients have already been reported to have anti-diabetic effects; however, further studies are required to obtain better quality extracts and higher yields of active ingredients. Reducose® is a commercially available aqueous extract of mulberry leaves with a high content of active ingredients. In this study, the biological activities of Reducose®, 1-deoxynojirimycin, and l-leucine were evaluated using a glucose-stimulated insulin secretion (GSIS) assay. The GSIS assay results were expressed as the glucose-stimulated index (GSI). Considering the pharmacological safety in pancreatic β-cells, the appropriate non-toxic concentrations were selected by screening for cytotoxicity of Reducose®, 1-deoxynojirimycin, and l-leucine before the GSIS assay. The effect of Reducose®, 1-deoxynojirimycin, and l-leucine on glucose-stimulated insulin secretion in INS-1 cells was compared. Reducose®, 1-deoxynojirimycin, and l-leucine increased the GSI values more effectively than gliclazide (positive control). This was associated with an increase in protein expression, such as peroxisome proliferator-activated receptor-γ, insulin receptor substrate-2, activated pancreatic and duodenal homeobox-1, which are related to the regulation of pancreatic β-cell function and survival. In order to elucidate the effect of Reducose® in anti-diabetic effects, blood glucose levels, insulin levels, and liver and lipid concentrations were investigated in a Sprague-Dawley rat model of high-fat diet/streptozotocin-induced diabetes. We observed that administration of Reducose® can decrease fasting blood glucose levels and reduce the production of AST, ALT, TG, and TC to a similar extent as metformin (positive control). These results suggested that Reducose® play a role in promoting GSIS but not enough to show that the content and proportion of 1-deoxynojirimycin and l-leucine play an important role in the GSIS activity of Reducose®.

This study was conducted to compare the effects of rumen-protected (RP-Leu) and unprotected L-leucine (RU-Leu) on the fermentation parameters, bacterial composition, and amino acid metabolism in vitro rumen batch incubation. The 5.00 g RP-Leu or RU-Leu products were incubated in situ in the rumen of four beef cattle (Bos taurus) and removed after 0, 2, 4, 6, 12, 16, and 24 h to determine the rumen protection rate. In in vitro incubation, both RP-Leu and RU-Leu were supplemented 1.5 mmol/bottle (L-leucine HCl), and incubated after 0, 2, 4, 6, 8, 12, and 16 h to measure gas production (GP), nutrient degradability, fermentation parameters, bacterial composition, and amino acids metabolism. Results from both in vitro and in situ experiments confirmed that the rumen protection rate was greater (p < 0.01) in RP-Leu than in RU-Leu, whereas the latter was slow (p < 0.05) degraded within incubation 8 h. Free leucine from RP-Leu and RU-Leu reached a peak at incubation 6 h (p < 0.01). RU-Leu supplementation increased (p < 0.05) gas production, microbial crude protein, branched-chain AAs, propionate and branched-chain VFAs concentrations, and Shannon and Sobs index in comparison to the control and RP-Leu supplementation. RU-Leu and RP-Leu supplementation decreased (p < 0.05) the relative abundance of Bacteroidota, which Firmicutes increased (p < 0.05). Correlation analysis indicated that there are 5 bacteria at the genus level that may be positively correlated with MCP and propionate (p < 0.05). Based on the result, we found that RP-Leu was more stable than RU-Leu in rumen fluid, but RU-Leu also does not exhibit rapid degradation by ruminal microbes for a short time. The RU-Leu was more beneficial in terms of regulating rumen fermentation pattern, microbial crude protein synthesis, and branched-chain VFAs production than RP-Leu in vitro rumen conditions.

BACKGROUND: L-Leucine is a high-value amino acid with promising applications in the medicine and feed industries. However, the complex metabolic network and intracellular redox imbalance in fermentative microbes limit their efficient biosynthesis of L-leucine.
RESULTS: In this study, we applied rational metabolic engineering and a dynamic regulation strategy to construct a plasmid-free, non-auxotrophic Escherichia coli strain that overproduces L-leucine. First, the L-leucine biosynthesis pathway was strengthened through multi-step rational metabolic engineering. Then, a cooperative cofactor utilization strategy was designed to ensure redox balance for L-leucine production. Finally, to further improve the L-leucine yield, a toggle switch for dynamically controlling sucAB expression was applied to accurately regulate the tricarboxylic acid cycle and the carbon flux toward L-leucine biosynthesis. Strain LEU27 produced up to 55 g/L of L-leucine, with a yield of 0.23 g/g glucose.
CONCLUSIONS: The combination of strategies can be applied to the development of microbial platforms that produce L-leucine and its derivatives.

Supplements and diets containing L-leucine, a branched-chain amino acid, have been considered beneficial for controlling oxidative stress and maintaining cardiac tissue in toxicity models using doxorubicin, a drug widely used in cancer treatment. However, there is a lack of studies in the literature that assess the effects of this diet on other organs and tissues, such as the liver and kidneys. Therefore, this study aimed to evaluate the effects of a leucine-rich diet on the liver and kidneys of healthy rats submitted to the doxorubicin toxicity model by analyzing biomarkers of oxidative stress and histological parameters. The animals were divided into four groups: naive, doxorubicin, L-leucine, and doxorubicin + L-leucine, and the diet was standardized with 5% L-leucine and a dose of 7.5 mg/kg of doxorubicin. We evaluated tissue injury parameters and biomarkers of oxidative stress, including enzymes, antioxidant profile, and oxidized molecules, in the liver and kidneys. Although some studies have indicated benefits of a diet rich in L-leucine for the muscle tissue of animals that received doxorubicin, our results showed that the liver was the most affected organ by the L-leucine-rich diet since the diet reduced its antioxidant defenses and increased the deposit of collagen and fat in the hepatic tissue. In the kidneys, the main alteration was the reduction in the number of glomeruli. These results contribute to the scientific literature and encourage further studies to evaluate the effects of an L-leucine-rich diet or its supplementation, alone or combined with doxorubicin using an animal model of cancer. Therefore, our study concludes that the leucine-rich diet itself was harmful and, when co-administered with doxorubicin, was not able to maintain the antioxidant defenses and tissue structure of the evaluated organs.

L-leucine is an essential amino acid widely used in food and pharmaceutical industries. However, the relatively low production efficiency limits its large-scale application. In this study, we rationally developed an efficient L-leucine-producing Escherichia coli strain. Initially, the L-leucine synthesis pathway was enhanced by overexpressing feedback-resistant 2-isopropylmalate synthase and acetohydroxy acid synthase both derived from Corynebacterium glutamicum, along with two other native enzymes. Next, the pyruvate and acetyl-CoA pools were enriched by deleting competitive pathways, employing the nonoxidative glycolysis pathway, and dynamically modulating the citrate synthase activity, which significantly promoted the L-leucine production and yield to 40.69 g/L and 0.30 g/g glucose, respectively. Then, the redox flux was improved by substituting the native NADPH-dependent acetohydroxy acid isomeroreductase, branched chain amino acid transaminase, and glutamate dehydrogenase with their NADH-dependent equivalents. Finally, L-leucine efflux was accelerated by precise overexpression of the exporter and deletion of the transporter. Under fed-batch conditions, the final strain LXH-21 produced 63.29 g/L of L-leucine, with a yield and productivity of 0.37 g/g glucose and 2.64 g/(L h), respectively. To our knowledge, this study achieved the highest production efficiency of L-leucine to date. The strategies presented here will be useful for engineering E. coli strains for producing L-leucine and related products on an industrial scale.

The Impact of Nutrition on Muscle Health in Older Individuals Abstract: The age-related change in the importance of nutrition for muscle health starts at the age of 50. Considering its effects on the mobility and physical independence of older people, the aging of the musculoskeletal system represents one of the greatest public health challenges and tasks for a demographically aging Switzerland. In particular sarcopenia, a pathological decrease in muscle strength, muscle mass and muscle function beyond the physiological age-related changes, correlates with a significantly increased risk of falls as well as increasing morbidity and mortality. Common chronic diseases related to old age not only promote additional muscle loss but also frailty, leading to an additional decline of the quality of life. General practitioners play a crucial role in the initial assessment of changing life circumstances and activity profiles of older people. Thanks to their medical care over many years they are able to identify functional impairments of their aging patients at an early stage and address them in time. This is important because the combination of a high-protein diet and exercise may be extremely effective for improving muscle health and function. Eating more proteins (taking into account the newly revised and increased daily protein requirement for healthy seniors of 1,0-1,2g/kg body weight (bw)) can significantly slow down age-related muscle loss. Depending on age and comorbidities, the daily protein requirement might be even higher (1,5 to 2,0g/kg bw). According to current studies, a minimal protein amount of 25-35g per main dish is recommended for optimal muscle growth stimulation among older individiuals. Thanks to their highly potent boosting power on myofibrillar protein synthesis rates the amino acid L-leucine and L-leucine-rich foods play an important role in elderly people\'s diet.
Zusammenfassung: Die altersmedizinisch veränderte Bedeutung der Ernährung für die Muskelgesundheit beginnt ab dem 50. Lebensjahr. Die Alterung des Bewegungsapparats ist aufgrund ihrer Auswirkungen auf die Mobilität und körperliche Selbstständigkeit älterer Menschen eine der grössten Herausforderungen und Aufgaben für die öffentliche Gesundheit einer sich im demografischen Wandel befindenden Schweiz. Insbesondere die Sarkopenie, eine über altersassoziierte Veränderungen hinausgehende pathologische Abnahme der Muskelkraft, Muskelmasse und Muskelfunktion, korreliert mit einem deutlich erhöhten Sturzrisiko sowie einer zunehmenden Morbidität und Mortalität. Im Alter gehäufte chronische Krankheiten begünstigen nicht nur den Muskelabbau, sondern fördern auch die Gebrechlichkeit, was zu einer zusätzlichen Beeinträchtigung der Lebensqualität führt. Hausärztinnen und Hausärzten kommt bei der Ersteinschätzung sich verändernder Lebensumstände und Aktivitätsprofile älterer Menschen eine besondere Rolle zuteil. Dank einer meist jahrelangen Betreuung können sie funktionelle Einbussen ihrer älter werdenden Patientinnen und Patienten frühzeitig identifizieren und rechtzeitig adressieren. Dies ist umso wichtiger, als hier mit einer einfachen Kombination aus proteinreicher Ernährung und körperlichem Training äusserst wirksam interveniert werden kann. Proteinreicher zu essen (unter Berücksichtigung des neu deutlich nach oben korrigierten täglichen Proteinbedarfs für gesunde Senioren von 1,0–1,2g/kg Körpergewicht (KG)) kann dabei den altersassoziierten Muskelabbau bereits massgeblich verlangsamen. Je nach Alter und Komorbiditäten liegt der tägliche Proteinbedarf noch höher (1,5 bis 2,0g/kg KG). Dabei empfiehlt es sich gemäss aktueller Studienlage, für eine optimale muskelwachstumsstimulierende Wirkung der Proteine pro Hauptmahlzeit die Menge von 25–35g nicht zu unterschreiten. Eine besondere Rolle kommt der Aminosäure L-Leucin und entsprechend L-Leucin-reichen Lebensmitteln zuteil, die ganz spezifisch die myofibrilläre Proteinsyntheserate zu steigern vermögen und somit einen begünstigenden Einfluss auf die Muskelgesundheit im Alter ausüben.

UNASSIGNED: The overuse of antibiotics has made public health and safety face a serious cisis. It is urgent to develop new clinical treatment methods to combat drug resistant bacteria to alleviate the health crisis. The efficiency of antibiotics is closely related to the metabolic state of bacteria. However, studies on fluoroquinolone resistant Salmonella are relatively rare.
UNASSIGNED: CICC21484 were passaged in medium with and without sarafloxacin and obtain sarafloxacin- susceptible Salmonella Typhimurium (SAR-S) and sarafloxacin resistant Salmonella Typhimurium (SAR-R), respectively. Non-targeted metabolomics was used to analyze the metabolic difference between SAR-S and SAR-R. Then we verified that exogenous L-leucine promoted the killing effect of sarafloxacin in vitro, and measured the intracellular ATP, NADH and reactive oxygen species levels of bacteria. Gene expression was determined using Real Time quantitative PCR.
UNASSIGNED: We confirmed that exogenous L-leucine increased the killing effect of sarafloxacin on SAR-R and other clinically resistant Salmonella serotypes. Exogenous L-leucine stimulated the metabolic state of bacteria, especially the TCA cycle, which increased the working efficiency of the electron transfer chain and increased the intracellular NADH, ATP concentration, and reactive oxygen species level. Our results suggest that when the metabolism of drug-resistant bacteria is reprogrammed, the bactericidal effect of antibiotics improves.
UNASSIGNED: This study further enhances research in the anti-drug resistance field at the metabolic level and provides theoretical support for solving the current problem of sarafloxacin drug resistance, a unique fluoroquinolone drug for animals and indicating the potential of L-leucine as a new antibiotic adjuvant.