Targeting FTO induces colorectal cancer ferroptotic cell death by decreasing SLC7A11/GPX4 expression.

Ferroptosis is a newly identified iron-dependent form of death that is becoming increasingly recognized as a promising avenue for cancer therapy. N6-methyladenosine (m6A) is the most abundant reversible methylation modification in mRNA contributing to tumorigenesis. However, the crucial role of m6A modification in regulating ferroptosis during colorectal cancer (CRC) tumorigenesis remains elusive. Herein, we find that m6A modification is increased during ferroptotic cell death and correlates with the decreased m6A demethylase fat mass and obesity-associated protein (FTO) expression. Functionally, we demonstrate that suppressing FTO significantly induces CRC ferroptotic cell death, as well as enhancing CRC cell sensitivity to ferroptosis inducer (Erastin and RSL3) treatment. Mechanistically, high FTO expression increased solute carrier family 7 member 11 (SLC7A11) or glutathione peroxidase 4 (GPX4) expressions in an m6A-YTHDF2 dependent manner, thereby counteracting ferroptotic cell death stress. In addition, we identify Mupirocin as a novel inhibitor of FTO, and Mupirocin induces CRC ferroptosis and inhibits tumor growth. Clinically, the levels of FTO, SLC7A11, and GPX4, are highly correlated expression in CRC tissues. Our findings reveal that FTO protects CRC from ferroptotic cell death in promoting CRC tumorigenesis through triggering SLC7A11/GPX4 expression.

Association of lipid profile and obesity in patients with polycystic ovary syndrome.

Objective. Abnormal lipid profile and obesity increase the risk of polycystic ovary syndrome (PCOS). PCOS patients may have a greater risk of infertility, metabolic syndrome (MetS) and cardiovascular disease (CVD) due to abnormal lipid profile and obesity. The aim of the study was to find the association between abnormal lipid profile and obesity in patients with PCOS. Methods. In this case-control study, a total of 102 female subjects (51 diagnosed PCOS and 51 age-matched healthy controls) were enrolled, aged between 20-40 years. Biochemical parameters such as total cholesterol (TC), triglycerides (TG), low-density lipoprotein-cholesterol (LDL-C), high-density lipoprotein-cholesterol (HDL-C), very low-density lipoprotein-cholesterol (VLDL-C), luteinizing hormone (LH), and follicle-stimulating hormone (FSH) were estimated. Anthropometric parameters such as body mass index (BMI), waist circumference (WC), hip circumference (HC), and waist-to-hip ratio (WHR) were recorded. A p<0.05 was considered statistically significant. Results. Mean of BMI, WC, WHR, LH, FSH, TC, TG, LDL-C, and VLDL-C was found significantly elevated in patients with PCOS as compared to controls (p<0.01). However, the mean of HDL-C was found significantly reduced in patients with PCOS as compared to controls (p<0.01). BMI has shown a significant positive correlation with WC (r=0.562, p<0.01) and WHR (r=0.580, p<0.01) among PCOS patients. LH has shown a significant positive correlation with FSH (r=0.572, p<0.01) among PCOS patients. TC has shown a significant positive correlation with TG (r=0.687, p<0.01), LDL-C (r=0.917, p<0.01), and VLDL-C (r=0.726, p<0.01) among PCOS patients. Conclusion. The results showed that abnormal lipid profile and obesity have a significant association with PCOS patients. Regular monitoring and treatment of PCOS patients are required to reduce the risk of infertility, MetS, and CVD.

Identification of Volatiles in Tomato Fruit Using Headspace Solid-Phase-Micro-Extraction (HS-SPME) Coupled with Gas Chromatography-Mass Spectrometry (GC-MS).

Plant volatile organic compounds (VOCs) are organic chemicals that plants release as part of their natural biological processes. Various plant tissues produce VOCs, including leaves, stems, flowers, and roots. VOCs are essential in plant communication, defense against pests and pathogens, aroma and flavor, and attracting pollinators. The study of plant volatiles has become an increasingly important area of research in recent years, as scientists have recognized these compounds' important roles in plant physiology. As a result, there has been a growing interest in developing methods for collecting and analyzing plant VOCs. HS-SPME-GC-MS (headspace solid-phase microextraction-gas chromatography-mass spectrometry) is commonly used for plant volatile analysis due to its high sensitivity and selectivity. This chapter describes an efficient method for extracting and identifying volatile compounds by HS-SPME coupled with GC-MS in tomato fruits.

Determination of Molecular Dimensions of Carbohydrate Polymers (Polysaccharides) by Size Exclusion Chromatography (SEC).

Calibrated size exclusion chromatography (SEC) is a useful tool for the analysis of molecular dimensions of polysaccharides. The calibration takes place with a set of narrow distributed dextran standards and peak position technique. Adapted columns systems and dissolving processes enable for the adequate separation of carbohydrate polymers. Plant-extracted fructan (a homopolymer with low molar mass and excellent water solubility) and mucilage (differently structured, high molar mass heteropolysaccarides that include existing supramolecular structures, and require a long dissolving time) are presented as examples of the versatility of this technique. Since narrow standards similar to the samples (chemically and structurally) are often unavailable, it must be noted that the obtained molar mass values and distributions by this method are only apparent (relative) values, expressed as dextran equivalents.

From molecules to visuals: Empowering drug discovery and development with mass spectrometry imaging.

Over the past three decades, mass spectrometry imaging (MSI) has emerged as a valuable tool for the spatial localization of drugs and metabolites directly from tissue surfaces without the need for labels. MSI offers molecular specificity, making it increasingly popular in the pharmaceutical industry compared to conventional imaging techniques like quantitative whole-body autoradiography (QWBA) and immunohistochemistry, which are unable to distinguish parent drugs from metabolites. Across the industry, there has been a consistent uptake in the utilization of MSI to investigate drug and metabolite distribution patterns, and the integration of MSI with omics technologies in preclinical investigations. To continue the further adoption of MSI in drug discovery and development, we believe there are two key areas that need to be addressed. First, there is a need for accurate quantification of analytes from MSI distribution studies. Second, there is a need for increased interactions with regulatory agencies for guidance on the utility and incorporation of MSI techniques in regulatory filings. Ongoing efforts are being made to address these areas, and it is hoped that MSI will gain broader utilization within the industry, thereby becoming a critical ingredient in driving drug discovery and development.

Innovative direct introduction-ion mobility-mass spectrometry (DI-IM-MS) approach for fast and robust isomer-specific quantification in a complex matrix: Application to 2'-fucosyllactose (2'-FL) in breast milk.

Identification and specific quantification of isomers in a complex biological matrix by mass spectrometry alone is not an easy task due to their identical chemical formula and therefore their same mass-to-charge ratio (m/z). Here, the potential of direct introduction combined with ion mobility-mass spectrometry (DI-IM-MS) for rapid quantification of isomers as human milk oligosaccharides (HMOs) was investigated. Differences in HMO profiles between various analyzed breast milk samples were highlighted using the single ion mobility monitoring (SIM2) acquisition for high ion mobility resolution detection. Furthermore, the Se+ (secretor) or Se- (non-secretor) phenotype could be assigned to breast milk samples studied based on their HMO contents, especially on the response of 2'-fucosyllactose (2'-FL) and lacto-N-fucopentaose I (LNFP I). The possibility of quantifying a specific isomer in breast milk by DI-IM-MS was also investigated. The standard addition method allowed the determination of the 2'-FL despite the presence of other oligosaccharides, including 3-fucosyllactose (3-FL) isomer in breast milk. This proof-of-concept study demonstrated the high potential of such an approach for the rapid and convenient quantification of isomers in complex mixtures.

Maintenance of Normal Blood Pressure From Middle to Older Age: Results From the Atherosclerosis Risk in Communities Study.

BACKGROUND: It is unknown whether maintaining normal blood pressure (BP) from middle to older age is associated with improved health outcomes. METHODS: We estimated the proportion of Atherosclerosis Risk in Communities study participants who maintained normal BP from 1987 to 1989 (visit 1) through 1996 to 1998 and 2011 to 2013 (over 4 and 5 visits, respectively). Normal BP was defined as systolic BP <120 mm Hg and diastolic BP <80 mm Hg, without antihypertensive medication. We estimated the risk of cardiovascular disease, dementia, and poor physical functioning after visit 5. In exploratory analyses, we examined participant characteristics associated with maintaining normal BP. RESULTS: Among 2699 participants with normal BP at baseline (mean age 51.3 years), 47.1% and 15.0% maintained normal BP through visits 4 and 5, respectively. The hazard ratios comparing participants who maintained normal BP through visit 4 but not visit 5 and through visit 5 versus those who did not maintain normal BP through visit 4 were 0.80 (95% CI, 0.63-1.03) and 0.60 (95% CI, 0.42-0.86), respectively, for cardiovascular disease, and 0.85 (95% CI, 0.71-1.01) and 0.69 (95% CI, 0.54-0.90), respectively, for poor physical functioning. Maintaining normal BP through visit 5 was more common among participants with normal body mass index versus obesity at visit 1, those with normal body mass index at visits 1 and 5, and those with overweight at visit 1 and overweight or normal body mass index at visit 5, compared with those with obesity at visits 1 and 5. CONCLUSIONS: Maintaining normal BP was associated with a lower risk of cardiovascular disease and poor physical functioning.

Association Between Body Mass Index, Obesity, and Clinical Outcomes Following Coronary Artery Bypass Grafting in Brazil: An Analysis of One Year of Follow-up of BYPASS Registry Patients.

OBJECTIVE: To investigate the association between body mass index (BMI), obesity, clinical outcomes, and mortality following coronary artery bypass grafting (CABG) in Brazil using a large sample with one year of follow-up from the Brazilian Registry of Cardiovascular Surgeries in Adults (or BYPASS) Registry database. METHODS: A multicenter cohort-study enrolled 2,589 patients submitted to isolated CABG and divided them into normal weight (BMI 20.0-24.9 kg/m2), overweight (BMI 25.0-29.9 kg/m2), and obesity (BMI > 30.0 kg/m2) groups. Inpatient postoperative outcomes included the most frequently described complications and events. Collected post-discharge outcomes included rehospitalization and mortality rates within 30 days, six months, and one year of follow-up. RESULTS: Sternal wound infections (SWI) rate was higher in obese compared to normal-weight patients (relative risk [RR]=5.89, 95% confidence interval [CI]=2.37-17.82; P=0.001). Rehospitalization rates in six months after discharge were higher in obesity and overweight groups than in normal weight group (χ=6.03, P=0.049); obese patients presented a 2.2-fold increase in the risk for rehospitalization within six months compared to normal-weight patients (RR=2.16, 95% CI=1.17-4.09; P=0.045). Postoperative complications and mortality rates did not differ among groups during time periods. CONCLUSION: Obesity increased the risk for SWI, leading to higher rehospitalization rates and need for surgical interventions within six months following CABG. Age, female sex, and diabetes were associated with a higher risk of mortality. The obesity paradox remains controversial since BMI may not be sufficient to assess postoperative risk in light of more complex and dynamic evaluations of body composition and physical fitness.

Metabolomic-Based Comparison of Daphnia magna and Japanese Medaka Responses After Exposure to Acetaminophen, Diclofenac, and Ibuprofen.

Pharmaceuticals are found in aquatic environments due to their widespread use and environmental persistence. To date, a range of impairments to aquatic organisms has been reported with exposure to pharmaceuticals; however, further comparisons of their impacts across different species on the molecular level are needed. In the present study, the crustacean Daphnia magna and the freshwater fish Japanese medaka, common model organisms in aquatic toxicity, were exposed for 48 h to the common analgesics acetaminophen (ACT), diclofenac (DCF), and ibuprofen (IBU) at sublethal concentrations. A targeted metabolomic-based approach, using liquid chromatography-tandem mass spectrometry to quantify polar metabolites from individual daphnids and fish was used. Multivariate analyses and metabolite changes identified differences in the metabolite profile for D. magna and medaka, with more metabolic perturbations for D. magna. Pathway analyses uncovered disruptions to pathways associated with protein synthesis and amino acid metabolism with D. magna exposure to all three analgesics. In contrast, medaka exposure resulted in disrupted pathways with DCF only and not ACT and IBU. Overall, the observed perturbations in the biochemistry of both organisms were different and consistent with assessments using other endpoints reporting that D. magna is more sensitive to pollutants than medaka in short-term studies. Our findings demonstrate that molecular-level responses to analgesic exposure can reflect observations of other endpoints, such as immobilization and mortality. Thus, environmental metabolomics can be a valuable tool for selecting sentinel species for the biomonitoring of freshwater ecosystems while also uncovering mechanistic information. Environ Toxicol Chem 2024;00:1-13. © 2024 The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC.

In situ fabrication of covalent organic frameworks on solid-phase microextraction probes coupled with electrospray ionization mass spectrometry for enrichment and determination of androgens in biosamples.

Solid-phase microextraction (SPME) coupled with electrospray ionization mass spectrometry (ESI-MS) was developed for rapid and sensitive determination of endogenous androgens. The SPME probe is coated with covalent organic frameworks (COFs) synthesized by reacting 1,3,5-tri(4-aminophenyl)benzene (TPB) with 2,5-dioctyloxybenzaldehyde (C8PDA). This COFs-SPME probe offers several advantages, including enhanced extraction efficiency and stability. The analytical method exhibited wide linearity (0.1-100.0 µg L-1), low limits of detection (0.03-0.07 µg L-1), high enrichment factors (37-154), and satisfactory relative standard deviations (RSDs) for both within one probe (4.0-14.8%) and between different probes (3.4-12.7%). These remarkable performance characteristics highlight the reliability and precision of the COFs-SPME-ESI-MS method. The developed method was successfully applied to detect five kinds of endogenous androgens in female serum samples, indicating that the developed analytical method has great potential for application in preliminary clinical diagnosis.

Characterization of banned colorants in cosmetics: A tandem mass-based molecular networking approach.

Colorants have been a staple in the cosmetics industry for a considerable time, although certain varieties have been banned owing to health risks. Detecting and confirming these banned colorants simultaneously poses several challenges when employing LC-MS/MS. Molecular networking is a promising analytical technology that can be used to predict the structure of components and the correlation between them using structural and MS/MS spectral similarities. Molecular networking entails assessing the number of fragmented ions and the cosine score (the closer it is to one, the higher the similarity). In this study, we developed and verified a method for the simultaneous quantitative analysis of the 26 banned colorants in cosmetics using LC-MS/MS. Additionally, we propose a novel approach that combines LC-Q-TOF-MS and molecular networking technology to detect banned colorants in cosmetics. For successful molecular networking, a minimum of six fragment ions with cosine scores exceeding 0.5 is required. We developed a screening method for characterizing banned colorants using molecular networking based on LC-TOF-MS results for 26 banned colorants. Furthermore, we demonstrated that our established method can be used for screening by analyzing actual cosmetics (eyebrow tattoo, lipstick tattoo, and hair tint) spiked with three non-targeted banned colorants with similar structures (m/z 267.116, 315.149, and 345.157) in cosmetics. The combination of molecular networking techniques and LC-MS/MS proves highly advantageous for the swift characterization and screening of non-targeted colorants in cosmetics.

Evaluation of pollution levels in sediments from Lake Edku, Egypt using laser ablation inductively coupled plasma mass spectrometry.

The concentrations of 11 heavy metals in sediments from Lake Edku, Egypt were determined using LA-ICP-MS. The average concentrations of elements occurred in the order of Fe > V > Cr > Zn > Ni > Cu > Co > Pb > As > Sn > Mo with respective values of 4.67 %, 104.8, 77.9, 76.6, 59.2, 52, 27.8, 19.8, 4.14, 2.24, and 1.45 µg/g. Several pollution indices were used to evaluate individual and cumulative contamination levels. All HMs were found to be in the deficiency to minimal enrichment range based on the enrichment factor. The contamination factor indicated low contamination levels of Cr and As, low to moderate contamination levels of Fe, Ni, Zn, Mo, Sn, and Pb, and moderate contamination levels of Co and Cu. The pollution load index and contamination degree indicated the sediments to be polluted and moderately polluted, respectively.

Structural basis for the interaction of Redß single strand annealing protein with Escherichia coli single-stranded DNA binding protein.

Redß is a protein from bacteriophage λ that binds to single-stranded DNA (ssDNA) to promote the annealing of complementary strands. Together with λ exonuclease (λ-exo), Redß is part of a two-component DNA recombination system involved in multiple aspects of genome maintenance. The proteins have been exploited in powerful methods for bacterial genome engineering in which Redß can anneal an electroporated oligonucleotide to a complementary target site at the lagging strand of a replication fork. Successful annealing in vivo requires the interaction of Redß with E. coli single-stranded DNA binding protein (SSB), which coats the ssDNA at the lagging strand to coordinate access of numerous replication proteins. Previous mutational analysis revealed that the interaction between Redß and SSB involves the C-terminal domain (CTD) of Redß and the C-terminal tail of SSB (SSB-Ct), the site for binding of numerous host proteins. Here, we have determined the x-ray crystal structure of Redß CTD in complex with a peptide corresponding to the last nine residues of SSB (MDFDDDIPF). Formation of the complex is predominantly mediated by hydrophobic interactions between two phenylalanine side chains of SSB (Phe-171 and Phe-177) and an apolar groove on the CTD, combined with electrostatic interactions between the C-terminal carboxylate of SSB and Lys-214 of the CTD. Mutation of any of these residues to alanine significantly disrupts the interaction of full-length Redß and SSB proteins. Structural knowledge of this interaction will help to expand the utility of Redß-mediated recombination to a wider range of bacterial hosts for applications in synthetic biology.

Stronger positive correlation of the left ventricular mass index and extracellular volume fraction with diastolic function in diabetic patients without myocardial infarction.

BACKGROUND: The structural and functional characteristics of the heart in patients with diabetes mellitus (DM) and without myocardial infarction (MI) are not fully understood. METHODS: We retrospectively analysed the data of patients with left ventricular ejection fraction (LVEF) ≥ 40% who underwent contrast-enhanced cardiac magnetic resonance imaging (CMR), which was also used to exclude MI, at two hospitals. Volumetric data and extracellular volume fraction (ECVf) of the myocardium evaluated using CMR were compared between patients with and without DM, and their association with diastolic function was evaluated. RESULTS: Among 322 analysed patients, 53 had DM. CMR revealed that the left ventricular mass index (LVMi) and ECVf were increased while LVEF was decreased in patients with DM after adjusting for patient characteristics (all P < 0.05). A stronger positive correlation was observed between LVMi and the early diastolic transmitral flow velocity to early diastolic mitral annular velocity ratio (E/e') in patients with DM than in those without DM (correlation coefficient [R] = 0.46, p = 0.001; R = 0.15, p = 0.021, respectively; p for interaction = 0.011). ECVf correlated with E/e' only in patients with DM (R = 0.61, p = 0.004). CONCLUSIONS: Patients with DM have increased LVMi and ECVf. Importantly, there was a difference between patients with and without DM in the relationship between these structural changes and E/e', with a stronger relationship in patients with DM. Furthermore, DM is associated with mildly reduced LVEF even in the absence of MI.

Volumetric dried blood spots for determination of phosphatidylethanol: Validation of a liquid chromatography tandem masspectrometry method and clinical application.

Phosphatidylethanol (PEth) measurement in whole blood samples is established as a specific alcohol biomarker with clinical and forensic applications. Establishment of dried blood spots (DBSs) as a specimen for PEth determination offers several advantages and was the focus of this work. A liquid chromatography tandem mass spectrometry method using a 96-well format for sample preparation was developed and validated. PEth was extracted from DBSs by using isopropanol containing PEth-d5 as internal standard. The blood sampling used a commercial volumetric DBS device having a phosholipase D inhibitor incorporated to stop continuous PEth formation. The method quantified PEth in the range of 0.05-10 µmol/L, with a bias and imprecision of less than 15%. In a clinical study (n = 25) using fingerprick blood, the volumetric device offered more precise quantifications (CV 4.6%) compared with the Whatman 903 Protein Saver card device (CV 16.6%). In another clinical study (n = 48), the use of dried venous and capillary blood, and liquid venous blood was compared under real-life conditions with samples sent by postal service. The capillary and venous DBS samples gave identical results while the liquid blood gave slightly higher values. Calculation of elimination half-life (PEth 16:0/18:1) in 31 cases based on two consecutive samples with 2-9 days in between gave results (mean 6.2 days) that agree with literature but several cases with values over 10 days. In conclusion, this study demonstrates that volumetric DBS is a valid specimen for determination of PEth blood concentrations, offering several advantages.

Baseline urinary osteopontin levels are associated with the improvement of metabolic syndrome.

BACKGROUND AND AIMS: While serum osteopontin (OPN)'s established role in cardiometabolic risk is recognized, its potential as a predictor of metabolic syndrome (MetS) improvement through a urine assay has not yet been demonstrated. In this study, we propose its potential predictive role over a 12-month period of standard care, with the ability to complement anthropometric measures. METHODS AND RESULTS: Hierarchical clustering revealed a notable association of urinary OPN (uOPN) with MetS criteria and overcame anthropometric measures in predicting the improvement at 12 months (OR of 2.74 [95% CI 1.32 to 6.29]). uOPN significantly contributed to the homogeneity of the nodes in the random forest and ultimately enhanced the performance of anthropometric measures when assessed for accuracy and area under the curve (AUC). CONCLUSION: Our findings offer insights into potential applications in cardiometabolic medicine for uOPN, which is easily detectable in non-invasive biological samples through an affordable assay.

An Efficient, Amine-Specific, and Cost-Effective Method for TMT 6/11-plex Labeling Improves the Proteome Coverage, Quantitative Accuracy and Precision.

Tandem mass tags (TMT) are widely used in proteomics to simultaneously quantify multiple samples in a single experiment. The tags can be easily added to the primary amines of peptides/proteins through chemical reactions. In addition to amines, TMT reagents also partially react with the hydroxyl groups of serine, threonine, and tyrosine residues under alkaline conditions, which significantly compromises the analytical sensitivity and precision. Under alkaline conditions, reducing the TMT molar excess can partially mitigate overlabeling of histidine-free peptides, but has a limited effect on peptides containing histidine and hydroxyl groups. Here, we present a method under acidic conditions to suppress overlabeling while efficiently labeling amines, using only one-fifth of the TMT amount recommended by the manufacturer. In a deep-scale analysis of a yeast/human two-proteome sample, we systematically evaluated our method against the manufacturer's method and a previously reported TMT-reduced method. Our method reduced overlabeled peptides by 9-fold and 6-fold, respectively, resulting in the substantial enhancement in peptide/protein identification rates. More importantly, the quantitative accuracy and precision were improved as overlabeling was reduced, endowing our method with greater statistical power to detect 42% and 12% more statistically significant yeast proteins compared to the standard and TMT-reduced methods, respectively. Mass spectrometric data have been deposited in the ProteomeXchange Consortium via the iProX partner repository with the data set identifier PXD047052.

Sex ratio shift after frozen single blastocyst transfer in relation to blastocyst morphology parameters.

The sex ratio shift was observed in peoples who underwent ART treatment. Moreover, there is limited evidence on differences in sex ratio between single frozen-thawed blastocyst morphology, insemination type and transfer days. So further research is needed in this area with regard to factors possibly affecting the sex ratio. Retrospective study based on multicenter including two large assisted reproduction centers in Shanghai and Wuhan in China. A total of 6361 singleton delivery offspring after frozen-thawed blastocyst transfer. Propensity score weighting and logistic regression models were used to estimate the associations between blastocyst morphology grading and child sex ratio. The main outcome measures is singleton sex ratio. In our study, the primary outcome measure was sex ratio which was calculated as the proportion of male newborns among all live births. Higher quality blastocysts resulted in a higher sex ratio than single poor-quality frozen-thawed blastocyst transfer. Among the three blastocyst morphological parameters of trophectoderm (TE), Grade A and B were significantly associated with a higher sex ratio than Grade C. The similar trend was observed in both IVF and ICSI treated subgroups. As compared with expansion (4 + 3), expansion degree 6 achieved a higher sex ratio in overall populations and IVF treated subgroup. Transferring blastocysts of day 6 had the highest sex ratio both in IVF group and ICSI group. A 6.95% higher sex ratio in transferring blastocysts of day 5 in IVF group than those in ICSI group. No significant association between inner cell mass degree and sex ratio was observed. However, as compared with IVF treatment, all morphology parameters achieved the similar or the biased sex ratio favoring female in ICSI treated subgroup. Quality of blastocysts was positively associated with sex ratio. TE score and expansion degree rather than ICM were significantly associated with sex ratio at birth. ICSI treatment promotes the biased sex ratio favoring female.

Investigations on Xenopus laevis body composition and feeding behavior in a laboratory setting.

The African clawed frog, Xenopus laevis, has been used as a laboratory animal for decades in many research areas. However, there is a lack of knowledge about the nutritional physiology of this amphibian species and the feeding regimen is not standardized. The aim of the present study was to get more insights into the nutrient metabolism and feeding behavior of the frogs. In Trial 1, adult female X. laevis were fed either a Xenopus diet or a fish feed. After 4 weeks, they were euthanized, weighed, measured for morphometrics and dissected for organ weights and whole-body nutrient analysis. There were no significant differences between the diet groups regarding the allometric data and nutrient contents. The ovary was the major determinant of body weight. Body fat content increased with body weight as indicator of energy reserves. In Trial 2, 40 adult female frogs were monitored with a specifically developed digital tracking system to generate heat-maps of their activity before and up to 25 min after a meal. Three diets (floating, sinking, floating & sinking) were used. The main feed intake activity was fanning the feed into the mouth, peaking until 20 min after the meal. The different swimming characteristics of the diets thereby influenced the activity of the animals. Our dataset helps to adjust the feeding needs to the physical composition and also to meet the natural behavioral patterns of feed intake as a prerequisite of animal wellbeing and animal welfare in a laboratory setting.