The effect of enterosgel on the activity of energy supply processes in rats at the same time affected by malathion and tetrachlormethane.

OBJECTIVE: Aim: The aim of the study was to investigate the activity of bioenergetic processes in rats under conditions of simultaneous exposure to malathion and carbon tetrachloride and after the use of enterosgel. PATIENTS AND METHODS: Materials and Methods: Experiments were conducted on rats. The rats were divided into nine groups.Malathion was administered daily (for 30 days) at a dose of 20 mg / kg body weight of the animal. Tetrachloromethane was administered twice (every other day) as a 50% oil solution at a dose of 1.0 ml / kg body weight. The intensity of energy supply processes was assessed by the activity of succinate dehydrogenase and cytochrome oxidase, impaired carbohydrate metabolism in terms of glucose and glycogen. RESULTS: Results: It was noted that succinate dehydrogenase activity in the liver decreased 2 times, in the myocardium - 1.6 times. On the thirty and seventh day of administration of toxicants after enterosorbent use, succinate dehydrogenase activity increased in the liver by 20%, cytochrome oxidase by 27%, in the myocardium - by 31% and 23%, respectively. The content of glucose in the serum after exposure to toxicants increased maximally (2.4 times) at the end of the study. In contrast, the glycogen content in the liver decreased by 48%, in the myocardium by 13%. The use of enterosgel resulted in a decrease in serum glucose. CONCLUSION: Conclusions: The use of enterosgel leads to the restoration of energy processes in the body of affected rats, which is confirmed by increased activity of mitochondrial enzymes, lowering glucose and increasing glycogen in the studied organs.

[Elevated liver enzymes: update 2024]. / Élévation des tests hépatiques et maladies stéatosiques du foie : nouveautés 2024.

Elevated liver enzymes are a common finding in primary care medicine, with an estimated prevalence of 8 %. Steatotic liver diseases are the most frequently encountered etiologies and r-epresent the main cause of liver-related morbidity and mortality. This article looks at the latest developments in these diseases, with a particular focus on MASLD (Metabolic dysfunction associated steatotic liver disease). Recommendations include biological monitoring every 1-3 years in the presence of risk factors, and the use of the FIB-4 score to detect fibrosis in cases of MASLD. Therapeutic management aims to improve metabolic function by treating risk factors and through lifestyle and dietary measures.

La découverte d'une élévation des tests hépatiques est courante en médecine de premier recours, sa prévalence est estimée à 8 %. Les maladies hépatiques stéatosiques sont les étiologies les plus fréquemment retrouvées et représentent la principale cause de morbimortalité liée au foie. Cet article aborde les nouveautés concernant ces maladies et plus particulièrement la MASLD ou « Metabolic Dysfunction Associated Steatotic Liver Disease ¼. Les recommandations préconisent un suivi biologique tous les 1-3 ans en présence de facteurs de risque et l'utilisation du score FIB-4 (fibrosis-4) pour dépister la fibrose en cas de MASLD. La prise en charge thérapeutique vise à améliorer la dysfonction métabolique par des mesures hygiénodiététiques et le traitement des facteurs de risque.

Liver enzyme levels in adolescents with obesity and insulin resistance: a propensity score matching analysis.

BACKGROUND: Elevated liver enzyme levels have been associated with metabolic syndrome in both obese and non-obese pediatric populations. This study aims to compare the serum liver enzyme levels in obese adolescents with and without insulin resistance (IR). METHODS: A cross-sectional analysis was conducted involving obese adolescents aged 10-18. We assessed somatometry, serum insulin levels, lipid profiles, and liver enzymes (aspartate aminotransferase [AST], alanine aminotransferase [ALT], and gamma-glutamyl transferase [GGT]). Statistical differences between groups were evaluated using Student's t-test or the Chi-squared test, with IR (wIR) status matched by propensity scores based on body mass index (BMI) z-scores. RESULTS: The study included 365 adolescents with obesity, 229 wIR, and 136 without (woIR). Before matching, the wIR group had a significantly higher BMI z-score (2.21 vs. 2.14, p = 0.032). After matching for BMI z-scores (n = 122 each group), the wIR group displayed significantly higher levels of AST (32.3 vs. 24.7, p < 0.001) and ALT (42.4 vs. 30.9, p < 0.001), but no significant differences were observed in GGT levels (37.4 vs. 32.5, p = 0.855). CONCLUSION: Obese adolescent's wIR exhibit higher serum ALT and AST levels, suggesting that altered AST is a potential risk factor for IR.

INTRODUCCIÓN: Se ha observado asociación entre niveles elevados de enzimas hepáticas y síndrome metabólico en población pediátrica con y sin obesidad. El objetivo del estudio fue comparar los niveles séricos de enzimas hepáticas entre adolescentes con obesidad con y sin resistencia a la insulina (RI). MÉTODOS: Se realizó un estudio transversal en adolescentes con obesidad entre 10 y 18 años. Se analizaron los datos somatometricos, insulina sérica, perfil lipídico y niveles de enzimas hepáticas (aspartato aminotransferasa [AST], alanina aminotransferasa [ALT] y gamma-glutamil transferasa [GGT]). Análisis estadístico: se utilizó t de Student o la prueba de Chi-cuadrado para evaluar diferencias entre grupos. Los pacientes con RI se emparejaron con pacientes sin RI utilizando puntuaciones de propensión basadas en la puntuación z del IMC. RESULTADOS: Se incluyeron un total de 365 adolescentes con obesidad (229 con RI y 136 sin RI). El grupo con RI tuvo un IMC mayor (con RI 2.21 vs sin RI 2.14 p = 0.032). Después de emparejar los grupos según el IMCz (n = 122 por grupo), el grupo con RI tuvo niveles de AST (24.7 vs., 32.3, p < 0.001) y ALT (30.9 vs., 42.4, p < 0.001) significativamente más altos en comparación al grupo sin RI. Sin embargo, no hubo diferencia en los niveles de GTT (37.4 vs 32.5, p = 0.855). CONCLUSIONES: Los niveles séricos de ALT y AST en adolescents con obesidad y RI fueron mayores. La AST alterada fue un factor de riesgo para presentar RI.

Effects of Propolis Consumption on Glycemic Indices and Liver Enzymes in Adults: A Grading of Recommendations Assessment, Development, and Valuation-assessed Systematic Review and Dose-Response Meta-analysis.

PURPOSE: Even though various randomized controlled trials (RCTs) have assessed the effect of propolis on glycemic indices and liver enzyme concentrations in adults, results have been inconsistent, without conclusive evidence. This systematic review and meta-analysis of RCTs sought to evaluate the effects of propolis consumption on glycemic indices and liver enzymes, fasting blood glucose, insulin, homeostatic model assessment of insulin resistance, glycosylated hemoglobin, alanine transaminase, aspartate aminotransferase, and gamma-glutamyl transferase in adults. METHODS: Two independent researchers systematically searched PubMed, EMBASE, Scopus, Web of Science, and the Cochrane Library for English-language RCTs published up to April 2024. The results were generated through a random-effects model and presented as the weighted mean difference (WMD) with a 95% CI. The Cochrane Risk of Bias Tool for RCTs and Grading of Recommendations Assessment, Development, and Evaluation assessment were used to evaluate quality assessment and certainty of evidence. FINDINGS: A total of 21 RCTs were included. A pooled analysis of 24 trials reported that propolis consumption led to a significant reduction in fasting blood glucose (WMD, -9.75 mg/dL; 95% CI, -16.14 to -3.35), insulin (WMD, -1.64 µU/mL; 95% CI, -2.61 to -0.68), glycosylated hemoglobin (WMD, -0.46%; 95% CI, -0.71 to -0.21), homeostatic model assessment of insulin resistance (WMD, -0.54; 95% CI, -0.98 to -0.09), alanine transaminase (WMD, -2.60 IU/L; 95% CI, -4.58 to -0.61), and aspartate aminotransferase (WMD, -2.07 IU/L; 95% CI, -3.05 to -1.09). However, there were no significant effects on gamma-glutamyl transferase in comparison with the control group. IMPLICATIONS: This meta-analysis has shown that propolis supplementation may have beneficial effects on glycemic indices and liver enzymes. Future high-quality, long-term RCTs are needed to confirm our results. CLINICALTRIALS: gov identifiers: CRD42024524763. (Clin Ther. 2024;46:XXX-XXX) © 2024 Elsevier HS Journals, Inc.

Mechanistic insights into condensate formation of human liver-type phosphofructokinase by stochastic modeling approaches.

Human liver-type phosphofructokinase 1 (PFKL) has been shown to regulate glucose flux as a scaffolder arranging glycolytic and gluconeogenic enzymes into a multienzyme metabolic condensate, the glucosome. However, it has remained elusive of how phase separation of PFKL is governed and initiates glucosome formation in living cells, thus hampering to understand a mechanism of glucosome formation and its functional contribution to human cells. In this work, we developed a stochastic model in silico using the principle of Langevin dynamics to investigate how biological properties of PFKL contribute to the condensate formation. The significance of an intermolecular interaction between PFKLs, an effective concentration of PFKL at a region of interest, and its own self-assembled filaments in formation of PFKL condensates and control of their sizes were demonstrated by molecular dynamics simulation using the Large-scale Atomic/Molecular Massively Parallel Simulator (LAMMPS). Such biological properties that define intracellular dynamics of PFKL appear to be essential for phase separation of PFKL, which may represent an initiation step for the formation of glucosome condensates. Collectively, our computational study provides mechanistic insights of glucosome formation, particularly an initial stage through the formation of PFKL condensates in living human cells.

Aging-Related CYP3A Functional Changes in Chinese Older Patients: New Findings from Model-Based Assessment of Amlodipine.

Aging-related alterations in hepatic enzyme activity, particularly of the CYP3A, significantly impact drug efficacy and safety in older adults, making it essential to understand how aging affects CYP function for optimal drug therapy. The exogenous probe substrate method, a minimally invasive approach to assess liver metabolic enzyme activity in vivo, is effective in studying these changes. Amlodipine being extensively metabolized (> 90%) in the liver, primarily via cytochrome P450 enzyme CYP3A was selected as a probe to investigate and quantify the factors affecting the aging-related changes of CYP3A in the Chinese older population. Amlodipine concentration data were collected from an ongoing noninterventional clinical study conducted at Peking University Third Hospital. A physiologically-based pharmacokinetic modeling approach, grounded in population pharmacokinetic (PPK) analysis, was employed to physiologically quantify the aging-related changes in CYP3A function. A total of 132 amlodipine concentrations from 69 patients were obtained from the clinical study. PPK analysis shows that frailty phenotype but not age is a significant influence and frail patients have 37% greater plasma amlodipine exposure than nonfrail patients. This difference in CYP3A function may be attributed to a 63.2% lower CYP3A relative abundance in the frail patients, compared with that in the nonfrail patients. In the context of dose selection for older adults, focusing on frailty rather than chronological age should be recognized as a more relevant approach, because frailty might more accurately reflect the individual's biological age. Our study suggested a need to shift the research focus from chronological age to biological age.

In vitro impacts of polystyrene microplastics and environmental pollutants on ethoxyresorufin-O-deethylase and glutathione S-transferase activity in Mossambica tilapia.

Microplastic (MP) pollution is a potential threat to marine organisms. In vitro toxicity of MPs and other pollutants, such as pharmaceutically active compounds (PhACs) and brominated flame retardants (BFRs), has been understudied. This study aimed to investigate the effects of polystyrene microplastics (PS-MPs) with different particle sizes on two biomarkers: ethoxyresorufin-O-deethylase (EROD) and glutathione S-transferase (GST) in tilapia liver homogenates. The study also examined the combined effects of PS-MPs with various environmental contaminants, including three metal ions (Cu2+, Zn2+, Pb2+), three BFRs, and six PhACs. PS-MPs alone had no remarkable effects on the two biomarkers at the selected concentrations. However, PS-MPs combined with other pollutants significantly affected the two biomarkers in most situations. For EROD activity, PS + metal ions (except Zn2+ at 1000 µg/L), PS + BFRs (except decabromodiphenyl oxide (BDE-209)) or PS+ trimethoprim (TMP) significantly inhibited activity values, whereas PS+ 4-acetaminophen (AMP) induced EROD activity. For GST, PS together with most tested pollutants (except PS+ ibuprofen (IBF)) greatly decreased the activities. Accordingly, future research should focus on combined toxicity of mixtures to set more reasonable environmental safety evaluation standards.

Hepatic angiotensin-converting enzyme 2 expression in metabolic dysfunction-associated steatotic liver disease and in patients with fatal COVID-19.

BACKGROUND: Metabolic dysfunction-associated steatotic liver disease (MASLD), characterised by hepatic lipid accumulation, causes inflammation and oxidative stress accompanied by cell damage and fibrosis. Liver injury (LI) is also frequently reported in patients hospitalised with coronavirus disease 2019 (COVID-19), while pre-existing MASLD increases the risk of LI and the development of COVID-19-associated cholangiopathy. Mechanisms of injury at the cellular level remain unclear, but it may be significant that severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) which causes COVID-19, uses angiotensin-converting expression enzyme 2 (ACE2), a key regulator of the 'anti-inflammatory' arm of the renin-angiotensin system, for viral attachment and host cell invasion. AIM: To determine if hepatic ACE2 levels are altered during progression of MASLD and in patients who died with severe COVID-19. METHODS: ACE2 protein levels and localisation, and histological fibrosis and lipid droplet accumulation as markers of MASLD were determined in formalin-fixed liver tissue sections across the MASLD pathological spectrum (isolated hepatocellular steatosis, metabolic dysfunction-associated steatohepatitis (MASH) +/- fibrosis, end-stage cirrhosis) and in post-mortem tissues from patients who had died with severe COVID-19, using ACE2 immunohistochemistry and haematoxylin and eosin and picrosirius red staining of total collagen and lipid droplet areas, followed by quantification using machine learning-based image pixel classifiers. RESULTS: ACE2 staining is primarily intracellular and concentrated in the cytoplasm of centrilobular hepatocytes and apical membranes of bile duct cholangiocytes. Strikingly, ACE2 protein levels are elevated in non-fibrotic MASH compared to healthy controls but not in the progression to MASH with fibrosis and in cirrhosis. ACE2 protein levels and histological fibrosis are not associated, but ACE2 and liver lipid droplet content are significantly correlated across the MASLD spectrum. Hepatic ACE2 levels are also increased in COVID-19 patients, especially those showing evidence of LI, but are not correlated with the presence of SARS-CoV-2 virus in the liver. However, there is a clear association between the hepatic lipid droplet content and the presence of the virus, suggesting a possible functional link. CONCLUSION: Hepatic ACE2 levels were elevated in nonfibrotic MASH and COVID-19 patients with LI, while lipid accumulation may promote intra-hepatic SARS-CoV-2 replication, accelerating MASLD progression and COVID-19-mediated liver damage.

Evaluation of patients with positive anti-mitochondiral antibody and normal alkaline phosphatase levels for primary biliary cholangitis.

Primary Biliary Cholangitis (PBC) is a chronic cholestatic liver disease typically diagnosed by elevated cholestatic liver enzymes and a positive anti-mitochondrial antibody (AMA) test. The clinical importance of AMA positivity in patients with normal cholestatic liver enzymes is unclear. The aim of this study was to determine the relationship between PBC and AMA positivity detected in individuals with normal cholestatic enzyme levels. The files of patients with AMA and/or AMA-M2 positivity between 2009 and 2018 and whose alkaline phosphatase (ALP) levels were below upper limit of normal (ULN) at initial admission were retrospectively analyzed. The ALP levels were normal in all patients. All patients had AMA positivity demonstrated by indirect immunofluorescence (IIF) or AMA-M2 positivity demonstrated by ELISA. A total of 16 patients underwent liver biopsy and seven (43.75%) showed changes consistent with those with PBC. A total of 12 patients were diagnosed with PBC and were treated and followed up with this diagnosis. People with AMA positivity and normal cholestasis enzyme levels are closely associated with PBC. Some of these patients were diagnosed with PBC as a result of biopsy and some were diagnosed by clinical and laboratory findings during follow-up.. The patients with an AMA titration of 1/20 were not associated with PBC. In our study, results similar to the studies confirmed by biopsies were obtained. In this regard, there is a need for prospective and retrospective studies with longer follow-up periods.

Structural basis for allosteric regulation of human phosphofructokinase-1.

Phosphofructokinase-1 (PFK1) catalyzes the rate-limiting step of glycolysis, committing glucose to conversion into cellular energy. PFK1 is highly regulated to respond to the changing energy needs of the cell. In bacteria, the structural basis of PFK1 regulation is a textbook example of allostery; molecular signals of low and high cellular energy promote transition between an active R-state and inactive T-state conformation, respectively. Little is known, however, about the structural basis for regulation of eukaryotic PFK1. Here, we determine structures of the human liver isoform of PFK1 (PFKL) in the R- and T-state by cryoEM, providing insight into eukaryotic PFK1 allosteric regulatory mechanisms. The T-state structure reveals conformational differences between the bacterial and eukaryotic enzyme, the mechanisms of allosteric inhibition by ATP binding at multiple sites, and an autoinhibitory role of the C-terminus in stabilizing the T-state. We also determine structures of PFKL filaments that define the mechanism of higher-order assembly and demonstrate that these structures are necessary for higher-order assembly of PFKL in cells.

PTER is a N-acetyltaurine hydrolase that regulates feeding and obesity.

Taurine is a conditionally essential micronutrient and one of the most abundant amino acids in humans1-3. In endogenous taurine metabolism, dedicated enzymes are involved in the biosynthesis of taurine from cysteine and in the downstream metabolism of secondary taurine metabolites4,5. One taurine metabolite is N-acetyltaurine6. Levels of N-acetyltaurine are dynamically regulated by stimuli that alter taurine or acetate flux, including endurance exercise7, dietary taurine supplementation8 and alcohol consumption6,9. So far, the identities of the enzymes involved in N-acetyltaurine metabolism, and the potential functions of N-acetyltaurine itself, have remained unknown. Here we show that the body mass index associated orphan enzyme phosphotriesterase-related (PTER)10 is a physiological N-acetyltaurine hydrolase. In vitro, PTER catalyses the hydrolysis of N-acetyltaurine to taurine and acetate. In mice, PTER is expressed in the kidney, liver and brainstem. Genetic ablation of Pter in mice results in complete loss of tissue N-acetyltaurine hydrolysis activity and a systemic increase in N-acetyltaurine levels. After stimuli that increase taurine levels, Pter knockout mice exhibit reduced food intake, resistance to diet-induced obesity and improved glucose homeostasis. Administration of N-acetyltaurine to obese wild-type mice also reduces food intake and body weight in a GFRAL-dependent manner. These data place PTER into a central enzymatic node of secondary taurine metabolism and uncover a role for PTER and N-acetyltaurine in body weight control and energy balance.

A case-control regression analysis of liver enzymes in obesity-induced metabolic disorders in South Asian females.

Excessive body weight may disrupt hepatic enzymes that may be aggravated by obesity-related comorbidities. The current case-control study was designed to evaluate the extent of liver enzyme alteration in obesity-related metabolic disorders. Obese females with BMI ≥ 30 suffering from metabolic disorders were grouped according to existing co-morbidity and their hepatic enzymes were compared with non-obese healthy females. The resultant data was subjected to analysis of variance and mean difference in liver enzymes were calculated at P = 0.05. Analysis of variance indicated that obese diabetic and obese hypertensive females had almost 96% and 67% increase in the concentration of gamma-glutamyl transferase than control, respectively (P<0.0001). The obese females suffering from diabetes and hypertension exhibited nearly 54% enhancement in alanine transaminase level (P<0.0001) and a 17% increase in aspartate aminotransferase concentration (P = 0.0028). Obesity along with infertility decline liver enzyme production and a 31% significant decline in aspartate aminotransferase was observed while other enzyme concentrations were not significantly altered. Regression analysis was performed on the resultant data to understand the association between liver enzyme alteration and the development of metabolic diseases. Regression analysis indicated that obese diabetic and obese diabetic hypertensive women had 20% production of normal liver enzymes and 80% enzymes produced abnormally. Obese hypertensive and obese infertile females had only 5% and 6% normal production of liver enzymes, respectively. This research leads to the conclusion that the ability of the liver to function normally is reduced in obesity-related diabetes and hypertension. This may be due to inflamed and injured liver and poses a serious threat to developing fatty liver disease and ultimately liver cirrhosis.

Non-linear association of liver enzymes with cognitive performance in the elderly: A cross-sectional study.

BACKGROUND: Although liver metabolic dysfunction has been found to potentially elevate susceptibility to cognitive impairment and dementia, there is still insufficient evidence to explore the non-linear association of liver enzymes with cognitive performance. Therefore, we aimed to elucidate the non-linear relationship between liver enzymes and cognitive performance. METHODS: In this cross-sectional study, 2764 individuals aged ≥ 60 who participated in the National Health and Nutrition Survey (NHANES) between 2011 and 2014 were included. The primary data comprised liver enzyme levels (alkaline phosphatase (ALP), aspartate aminotransferase (AST), alanine aminotransferase (ALT), AST/ALT ratio, and gamma-glutamyl transferase (GGT)), and cognitive performance was the major measured outcome. The associations were analyzed using weighted multivariate logistic regression, subgroup analysis, a generalized additive model, smooth fitting curves, and threshold effects. RESULTS: The results of the fully adjusted model indicated that ALP was negatively associated with the animal fluency test (AFT) score (OR = 1.48, 95% CI: 1.11-1.98), whereas ALT demonstrated a positive association with the consortium to establish a registry for Alzheimer's disease (CERAD) test score (OR = 0.72, 95% CI: 0.53-0.97). Additionally, the AST/ALT ratio was negatively associated with the global cognitive test (OR = 2.39, 95% CI: 1.53-3.73), CERAD (OR = 2.61, 95% CI: 1.77-3.84), and digit symbol substitution test (DSST) scores (OR = 2.51, 95% CI: 1.57-4.02). GGT was also negatively associated with the AFT score (OR = 1.16, 95% CI: 1.01-1.33) in unadjusted model. A non-linear relationship was observed between liver enzymes and the risk of cognitive impairment as assessed by the global cognitive test. Specifically, when ALP > 60 U/L, 0.77 < AST/ALT < 1.76, and 25 < GGT < 94 U/L, higher liver enzyme levels were significantly associated with an elevated cognitive impairment risk, while a lower cognitive impairment risk when ALT level was > 17 U/L. CONCLUSIONS: There is a non-linear relationship between liver enzymes and cognitive performance, indicating that liver enzyme levels should be maintained within a certain level to mitigate the risk of cognitive impairment.

Possible involvement of sialidase and sialyltransferase activities in a stage-dependent recycling of sialic acid in some organs of type 1 and type 2 diabetic rats.

Background: Type 1 (T1D) and type 2 (T2D) diabetes lead to an aberrant metabolism of sialoglycoconjugates and elevated free serum sialic acid (FSSA) level. The present study evaluated sialidase and sialyltranferase activities in serum and some organs relevant to diabetes at early and late stages of T1D and T2D. Methods: Sialic acid level with sialidase and sialyltransferase activities were monitored in the serum, liver, pancreas, skeletal muscle and kidney of diabetic animals at early and late stages of the diseases. Results: The FSSA and activity of sialidase in the serum were significantly increased at late stage of both T1D and T2D while sialic acid level in the liver was significantly decreased in the early and late stages of T1D and T2D, respectively. Furthermore, the activity of sialidase was significantly elevated in most of the diabetes-relevant organs while the activity of sialyltransferase remained largely unchanged. A multiple regression analysis revealed the contribution of the liver to the FSSA while pancreas and kidney contributed to the activity of sialidase in the serum. Conclusions: We concluded that the release of hepatic sialic acid in addition to pancreatic and renal sialidase might (in)directly contribute to the increased FSSA during both types of diabetes mellitus.

Screening for metabolic dysfunction-associated fatty liver disease: Time to discard the emperor's clothes of normal liver enzymes?

Metabolic dysfunction-associated fatty liver disease (MAFLD) is the most prevalent chronic liver condition worldwide. Current liver enzyme-based screening methods have limitations that may missed diagnoses and treatment delays. Regarding Chen et al, the risk of developing MAFLD remains elevated even when alanine aminotransferase levels fall within the normal range. Therefore, there is an urgent need for advanced diagnostic techniques and updated algorithms to enhance the accuracy of MAFLD diagnosis and enable early intervention. This paper proposes two potential screening methods for identifying individuals who may be at risk of developing MAFLD: Lowering these thresholds and promoting the use of noninvasive liver fibrosis scores.

RNA Adduction Resulting from the Metabolic Activation of Myristicin by P450 Enzymes and Sulfotransferases.

Myristicin (MYR) mainly occurs in nutmeg and belongs to alkoxy-substituted allylbenzenes, a class of potentially toxic natural chemicals. RNA interaction with MYR metabolites in vitro and in vivo has been investigated in order to gain a better understanding of MYR toxicities. We detected two guanosine adducts (GA1 and GA2), two adenosine adducts (AA1 and AA2), and two cytosine adducts (CA1 and CA2) by LC-MS/MS analysis of total RNA extracts from cultured primary mouse hepatocytes and liver tissues of mice after exposure to MYR. An order of nucleoside adductions was found to be GAs > AAs > CAs, and the result of density functional theory calculations was in agreement with that detected by the LC-MS/MS-based approach. In vitro and in vivo studies have shown that MYR was oxidized by cytochrome P450 enzymes to 1'-hydroxyl and 3'-hydroxyl metabolites, which were then sulfated by sulfotransferases (SULTs) to form sulfate esters. The resulting sulfates would react with the nucleosides by SN1 and/or SN2 reactions, resulting in RNA adduction. The modification may alter the biochemical properties of RNA and disrupt RNA functions, perhaps partially contributing to the toxicities of MYR.

Impact of Surfactants on Cumulative Trypsin Activity in Bottom-Up Proteome Analysis.

Trypsin digestion plays a pivotal role in successful bottom-up peptide characterization and quantitation. While denaturants are often incorporated to enhance protein solubility, surfactants are recognized to inhibit enzyme activity. However, several reports have suggested that incorporating surfactants or other solvent additives may enhance digestion and MS detection. Here, we assess the impacts of ionic surfactants on cumulative trypsin activity and subsequently evaluate the total digestion efficiency of a proteome mixture by quantitative MS. Although low surfactant concentrations, such as 0.01% SDS or 0.2% SDC, significantly enhanced the initial trypsin activity (by 14 or 42%, respectively), time course assays revealed accelerated enzyme deactivation, evident by 10- or 40-fold reductions in trypsin activity half-life at these respective surfactant concentrations. Despite enhanced initial tryptic activity, quantitative MS analysis of a common liver proteome extract, digested with various surfactants (0.01 or 0.1% SDS, 0.5% SDC), consistently revealed decreased peptide counts and signal intensity, indicative of a lower digestion efficiency compared to a nonsurfactant control. Furthermore, including detergents for digestion did not improve the detection of membrane proteins, nor hydrophobic peptides. These results stress the importance of assessing cumulative enzyme activity when optimizing the digestion of a proteome mixture, particularly in the presence of denaturants.

The effect of various dietary MUFA content and n-6/n-3 ratios on rainbow trout (Oncorhynchus mykiss) fed on a whole plant protein based diet: growth performance, digestive enzymes activity, intestinal morphometry and fatty acids profile of muscle and liver.

The effect of diets with various dietary MUFA content and n-6/n-3 ratios, diets 1 (55.33, 1.00), 2 (25.30, 1.00), 3 (55.13, 2.05), 4 (24.92, 2.03), 5 (54.94, 8.06) and 6 (24.91, 8.06) and a control diet with fish oil (FO), diet 7 (33.60, 5.97), was studied on growth and digestive physiology of rainbow trout, Oncorhynchus mykiss. Juveniles, 14.65 g ± 0.17, were fed the experimental diets for eight weeks. Those fish fed diet 1 (55.33, 1.00) had the lowest growth and nutritional indices, while fish fed diet 6 (24.91, 8.06) possessed the highest indices. However, fish fed D7 (33.60, 5.97) was intermediate in this regard. Proximate body composition results revealed no significant differences among various experimental groups (P > 0.05). Fish fed on diet 1 possessed the highest alkaline protease activity, while fish raised on diet 2 showed the lowest enzyme activity (P < 0.05). Fish fed on diets 1, 3 and 4 had the highest lipase activity (P > 0.05). Amylase activity and intestinal parameters did not differ among groups (P > 0.05). MUFA contents of liver and muscle reflected the MUFA contents of the diets; however, liver PUFA contents was not affected by dietary PUFA contents (P < 0.05). However, 18:3n-3 contents of liver decreased as dietary n-6/n-3 ratio increased (P < 0.05). Furthermore, the liver 20:4n-6 contents considerably increased as dietary n-6/n-3 increased to 8.06 (P < 0.05). Muscle 22:6n-3 content of groups 1 to 6 was lower than group 7 (P < 0.05). In conclusion, rainbow trout was considerably capable of de novo synthesis of 22:6n-3. Meanwhile, increasing dietary n-6/n-3 ratio to 8.06 decreased the muscle 22:6n-3 content which requires further considerations regarding fish immune competence and nutritional quality for human consumption.

Hepatic enzyme induction and its potential effect on thyroid hormone metabolism in the metamorphosing tadpole of Xenopus laevis (African clawed frog).

Hepatic enzyme induction, an inherent defense system against xenobiotics, is known to simultaneously affect endocrine system functions in mammals under specific conditions, particularly thyroid hormone (TH) regulation. While this phenomenon has been studied extensively, the pathway leading to this indirect thyroid effect in mammals has unclear applicability to amphibians, despite the importance of amphibian species in assessing thyroid-disruptive chemicals. Here, we investigated the effects of three well-known mammalian enzyme inducers-ß-naphthoflavone (BNF), pregnenolone carbonitrile (PCN), and sodium phenobarbital (NaPB)-on the gene expression of phase-I and phase-II metabolizing enzymes in Xenopus laevis tadpoles. Waterborne exposure to BNF and PCN significantly induced the expression of both phase-I (cytochrome P450, CYP) and phase-II enzymes (UDP-glucuronosyltransferase, UGT and sulfotransferase, SULT), but in different patterns, while NaPB exposure induced CYP2B expression without affecting phase-II enzymes in tadpoles, in contrast to mammals. Furthermore, an ex vivo hepatic enzyme activity assay confirmed that BNF treatment significantly increased phase-II metabolic activity (glucuronidation and sulfation) toward TH. These results suggest the potential for certain mammalian enzyme inducers to influence TH clearance in X. laevis tadpoles. Our findings provide insights into the profiles of xenosensing activity and enzyme induction in amphibians, which can facilitate a better understanding of the mechanisms of indirect effects on the thyroid system via hepatic enzyme induction in nonmammalian species.

Moisture content in diets in the co-feeding phase of Pseudoplatystoma sp. influences performance and digestive process.

Live food in the initial life stages of neotropical fish is essential for their development and health; however, it can significantly increase production costs. This study uses complete diets with varying moisture contents (47%, 35%, 24%, and 8%) as a cost-effective alternative in the co-feeding phase of surubim larvae, assessing their influence on development, digestive enzymes, and liver metabolism. In a completely randomized design, 3200 three-day-old Pseudoplatystoma sp. larvae (0.001 g) were distributed evenly among 16 aquariums (20 L), with 200 individuals per aquarium. For the first five days, all larvae were fed Artemia exclusively, after which they were fed experimental diets with varying levels of humidity (47%, 35%, 24%, and 8%) six times a day across four treatments and four replicates. The 21-day feeding trial demonstrated that larvae fed with 24% and 8% moisture diets exhibited increased (p < 0.05) weight gain, final length, and protein efficiency rate. The remaining growth parameters (i.e., specific growth rate and condition factor) did not show significant differences (p > 0.05) among the dietary treatments. Enzymatic analysis revealed that the 47% moisture diet enhanced the amylase and alkaline phosphatase activities, whereas the 24% and 35% moisture diets elevated the lipase and protease activities. The 47% moisture diet also resulted in increased alanine aminotransferase, aspartate aminotransferase, and albumin levels, along with visible hepatic histopathologies in samples, such as visible lipid vacuoles, displacement of the nucleus of the hepatocyte, and increased sinusoid spaces. No significant liver changes were observed in fish fed with other diets. Principal component analysis showed that diets with 8-24% moisture content were the most beneficial during the co-feeding phase of surubim larviculture.