Age-dependent Changes in Plasma Amino Acids Contribute to Alterations in Glycoxidation Products

The covalent immobilization of β-galactosidase from Aspergillus oryzae and alkaline protease from Bacillus licheniformis on amino-functionalized multi-walled carbon nanotubes in milk

This study aimed was to covalently immobilize β-galactosidase from Aspergillus oryzae and protease from Bacillus licheniformis on amino-functionalized multi-walled carbon nanotubes. In this study, a two-level factorial design was employed to investigate the impact of seven continuous variables (activation pH, glutaraldehyde molarity, activation time (0-8 h), buffer solution pH (8-0), buffer solution molarity, MWCNT-NH 2 -glutaraldehyde quantity, and stabilization time (0-180 h)) on the immobilization efficiency and enzymatic activity of protease and β-galactosidase. Furthermore, the effect of time on the percentage of enzymatic activity was examined during specific intervals (24, 48, 72, 96, and 120 h) of the immobilization process. The analysis of variance results for protease enzymatic activity revealed a notable influence of the seven variables on immobilization efficiency and enzymatic activity. Additionally, the findings indicate that activation time, buffer pH, MWCNT-NH 2 -glutaraldehyde quantity, and stabilization time significantly affect the activity of the protease enzyme. The interplay between buffer pH and stabilization time is also significant. Indeed, both activation time and the quantity of MWCNT-NH 2 -glutaraldehyde exert a reducing effect on enzyme activity. Notably, the influence of MWCNT-NH 2 -glutaraldehyde quantity is more significant (p < 0.05). In terms of beta-galactosidase enzymatic activity, the study results highlight that among the seven variables considered, only the glutaraldehyde molarity, activation time, and the interplay of activation time and the quantity of MWCNT-NH 2 -glutaraldehyde can exert a statistically significant positive impact on the enzyme's activity (p < 0.05). The combination of activation time and buffer solution molarity, as well as the interactive effect of buffer pH and MWCNT-NH2-glutaraldehyde, can lead to a significant improvement in the stabilization efficiency of the protease of carbon nanotubes. The analysis of variance results demonstrated that the efficiency of covalently immobilizing β-galactosidase from Aspergillus oryzae on amino-functionalized multi-walled carbon nanotubes is influenced by the molarity of glutaraldehyde, buffer pH, stabilization time, and the interplay of activation time + buffer pH, buffer pH + activation time, activation time + buffer molarity, and glutaraldehyde molarity + MWCNT-NH 2 -glutaraldehyde (p < 0.05). Through the optimization and selection of optimal formulations, the obtained results indicate enzyme activities and stabilization efficiencies of 64.09 % ± 72.63 % and 65.96 % ± 71.77 % for protease and beta-galactosidase, respectively. Moreover, increasing the enzyme stabilization time resulted in a reduction of enzyme activity. Furthermore, an increase in pH, temperature, and the duration of milk storage passing through the enzyme-immobilized carbon nanotubes led to a decrease in enzyme stabilization efficiency, and lactose hydrolysis declined progressively over 8-h. Hence, the covalent immobilization of β-galactosidase from Aspergillus oryzae and protease from Bacillus licheniformis onto amino-functionalized multi-walled carbon nanotubes is anticipated to be achievable for milk applications.

Dietary protein and amino acid intakes for mitigating sarcopenia in humans

Adult humans generally experience a 0.5-1%/year loss in whole-body skeletal muscle mass and a reduction of muscle strength by 1.5-5%/year beginning at the age of 50 years. This results in sarcopenia (aging-related progressive losses of skeletal muscle mass and strength) that affects 10-16% of adults aged ≥ 60 years worldwide. Concentrations of some amino acids (AAs) such as branched-chain AAs, arginine, glutamine, glycine, and serine are reduced in the plasma of older than young adults likely due to insufficient protein intake, reduced protein digestibility, and increased AA catabolism by the portal-drained viscera. Acute, short-term, or long-term administration of some of these AAs or a mixture of proteinogenic AAs can enhance blood flow to skeletal muscle, activate the mechanistic target of rapamycin cell signaling pathway for the initiation of muscle protein synthesis, and modulate the metabolic activity of the muscle. In addition, some AA metabolites such as taurine, β-alanine, carnosine, and creatine have similar physiological effects on improving muscle mass and function in older adults. Long-term adequate intakes of protein and the AA metabolites can aid in mitigating sarcopenia in elderly adults. Appropriate combinations of animal- and plant-sourced foods are most desirable to maintain proper dietary AA balance.

The effects of fenugreek seed extract supplementation in patients with Alzheimer's disease: A randomized, double-blind, placebo-controlled trial

The aim of the current randomized control trial (RCT) study was to investigate the effects of fenugreek seed extract on memory, depression, quality of life, blood pressure, and serum malondialdehyde (MDA) and total antioxidant capacity (TAC) levels in adult AD patients. This randomized clinical trial was conducted in geriatric homes in Iran. The study participants included 82 AD patients with mild-to-moderate memory deficit. Patients in the intervention group received 5 cc of fenugreek seed extract for 4 months and subjects in the control group received a placebo. Memory, depression, quality of life, and BP levels, as well as serum MDA and TAC, were assessed before and after the intervention. There was a significant increase in serum levels of TAC (p < 0.001) and a reduction in serum MDA status (p < 0.001) after 4 months of fenugreek seed extract supplementation. In addition, increasing levels of memory (p < 0.001) and quality of life (p < 0.001), as well as reduction of depression (p = 0.002), systolic BP (p < 0.001), and diastolic BP (p < 0.001) levels were detected in the intervention group compared with baseline. Fenugreek seed extract supplementation in AD patients shows promising positive effects on memory, quality of life, BP, and selective oxidative indices levels.

Metabolic Impairment in Coronary Artery Disease: Elevated Serum Acylcarnitines Under the Spotlights

Coronary artery disease (CAD) remains the leading cause of death worldwide. Expanding patients' metabolic phenotyping beyond clinical chemistry investigations could lead to earlier recognition of disease onset and better prevention strategies. Additionally, metabolic phenotyping, at the molecular species level, contributes to unravel the roles of metabolites in disease development. In this cross-sectional study, we investigated clinically healthy individuals (n = 116, 65% male, 70.8 ± 8.7 years) and patients with CAD (n = 54, 91% male, 67.0 ± 11.5 years) of the COmPLETE study. We applied a high-coverage quantitative liquid chromatography-mass spectrometry approach to acquire a comprehensive profile of serum acylcarnitines, free carnitine and branched-chain amino acids (BCAAs), as markers of mitochondrial health and energy homeostasis. Multivariable linear regression analyses, adjusted for confounders, were conducted to assess associations between metabolites and CAD phenotype. In total, 20 short-, medium- and long-chain acylcarnitine species, along with L-carnitine, valine and isoleucine were found to be significantly (adjusted p ≤ 0.05) and positively associated with CAD. For 17 acylcarnitine species, associations became stronger as the number of affected coronary arteries increased. This implies that circulating acylcarnitine levels reflect CAD severity and might play a role in future patients' stratification strategies. Altogether, CAD is characterized by elevated serum acylcarnitine and BCAA levels, which indicates mitochondrial imbalance between fatty acid and glucose oxidation.

Association of dietary intake, medication and anthropometric indices with serum levels of advanced glycation end products, caspase-3, and matrix metalloproteinase-9 in diabetic patients

Background and objective

Increased serum levels of advanced glycation end products (AGEs), caspase-3 (Cas-3) and matrix metalloproteinase-9 (MMP-9) have been reported in diabetic patients. This study aimed to evaluate association of anthropometric, dietary, and therapeutic factors with serum levels of methylglyoxal (MGO), carboxymethyl lysine (CML), pentosidine (Pen), Cas-3, and MMP-9 in diabetic patients.

Methods

The current study included 36 diabetic subjects. Dietary intake of the participants was assessed using three-day 24-h recall survey and anthropometric indices were measured. Demographic factors and medication intake of every subject were obtained. Serum levels of CML, MGO, Pen, MMP-9, and Cas-3 were measured using ELISA method.

Results

Gliclazide consumption was positively correlated with MMP-9 and Cas-3, but not AGEs levels. Females had higher MGO level compared with males. Further, CML levels were negatively correlated with BMI and WHR. Dietary protein intake was positively correlated with MMP-9, Cas-3, and MGO levels. As well as dietary energy and fat intake had significant positive relationship with serum Cas-3 concentration.

Conclusion

It is concluded that anthropometric characteristics, dietary intake, and therapeutic medications are possible factors that may determine the circulating levels of AGEs, MMP-9, and Cas-3 in patients with diabetes.

Differences and Effects of Metabolic Fate of Individual Amino Acid Loss in High-Efficiency Hemodialysis and Hemodiafiltration

OBJECTIVE

The objective of the study was to quantify the loss and arterial blood concentration of the three main classes of amino acids (AAs)-nonessential amino acids (NEAAs), essential amino acids (EAAs), and branched-chain amino acids-as resulting from high-efficiency hemodialysis (HED) and hemodiafiltration (HDF). We moreover aimed to identify the different fates and metabolic effects manifested in patients undergoing hemodialysis and the consequences on body composition and influence of nutritional decline into protein energy wasting.

DESIGN AND METHODS

Identical dialysis monitors, membranes, and dialysate/infusate were used to ensure consistency. Ten patients were recruited and randomized to receive treatment with on-line modern HED and HDF. Arterial plasma concentrations of individual AAs were compared in healthy volunteers and patients undergoing hemodialysis, and AA levels outflowing from the dialyzer were evaluated. Baseline AA plasma levels of patients undergoing hemodialysis were compared with findings obtained 1 year later.

RESULTS

A severe loss of AA with HED/HDF was confirmed: a marked loss of total AAs (5 g/session) was detected, corresponding to more than 65% of all AAs. With regard to individual AAs, glutamine displayed a consistent increase (+150%), whereas all other AAs decreased after 12 months of HD/HDF. Only a few AAs, such as proline, cysteine, and histidine maintained normal levels. The most severe metabolic consequences may result from losses of EAAs such as valine, leucine, and histidine and from NEAAs including proline, cysteine, and glutamic acid eliciting the onset of hypercatabolism threatening muscle mass loss.

CONCLUSION

Dialysis losses, together with the effect of chronic uremia, resulted in a reduction of fundamental EAAs and NEAAs, which progressively led our patients after 12 months to a deterioration of lean mass toward sarcopenia. Therefore, the reintroduction of a correctly balanced AA supplementation in patients undergoing HD to prevent or halt decline of hypercatabolism into cachexia is recommended.

Exploring the role of body mass index in relationship of serum nitric oxide and advanced glycation end products in apparently healthy subjects

This study aimed to identify any association of serum nitric oxide (NO) and advanced glycation end products (AGEs) with body mass index (BMI) in apparently healthy subjects. In this cross-sectional study, participants were 90 apparently healthy subjects, categorized into three BMI groups as follows: BMI≤19.5 (n = 21), 19.6≤BMI≤24.9 (n = 35), and BMI≥25 (n = 34). Serum levels of NO were measured by griess reaction method. Determination of serum pentosidine and carboxymethyllysine (CML) was done using ELISA. Median (95% confidence interval [CI]: lower- upper) of serum NO in subjects with BMI≥25 were 68.94 (CI: 55.01–70.56) μmol/L, which was higher compared with 19.6≤BMI≤24.9 and BMI≤19.5 groups (22.65 (CI: 19.29–28.17) μmol/L and 8.00 (CI: 9.12–29.58) μmol/L, respectively). Serum NO positively correlated with BMI in total subjects (r = 0.585, p<0.001), which this correlation was significant in both male and female groups (r = 0.735, p<0.001 and r = 0.476, p = 0.001, respectively). Serum pentosidine and CML were significantly lower in subjects with higher BMI. Further, BMI showed negative correlations with pentosidine and CML (r = -0.363, p<0.001 and r = -0.484, p<0.001, respectively). There were not any significant differences in serum NO, pentosidine, and CML levels between sex groups. After adjusting the effects of confounders (BMI, sex, age, and waist to hip ratio), serum NO significantly correlated with serum pentosidine and CML (r = -0.319, p = 0.003 and r = -0.433, p<0.001, respectively). It is concluded that higher BMI is accompanied by increased serum NO and suppressed pentosidine and CML.