Mitigation effects of high methoxyl pectin on acrylamide formation in the Maillard model system.

Acrylamide (AA) is a potential carcinogen formed during the process of food heating. Pectin is natural food additive widely presented in fruits and vegetables. This study aimed at investigating the influence of the addition of high methoxyl apple pectin (esterification degree: 82.6%) on AA inhibition in the asparagine (Asn)/glucose (Glc) model system. Results showed that temperature (120-180 °C), pH value (6.0-7.2), pectin addition (0.2-1.0%, w/v), substrate concentration (0.01-0.5 M) and molar ratio of Asn/Glc (5:1-1:10) had significant influence on inhibition of pectin on AA formation. With adding 1.0% (w/v) pectin, the pH value, Glc consumption and Schiff base abundance declined in Asn/Glc model system. Moreover, heating treatment decreased the pH value, molecular weight, esterification degree and galacturonic acid content of pectin. Finally, the pectin degradation product was identified, which might compete with Glc for Asn in Maillard reaction, led to AA reduction. This study provided distinct evidence for controlling AA formation.

The Use and Underuse of Model Systems in Infectious Disease Ecology and Evolutionary Biology.

AbstractEver since biologists began studying the ecology and evolution of infectious diseases (EEID), laboratory-based model systems have been important for developing and testing theory. Yet what EEID researchers mean by the term "model systems" and what they want from them is unclear. This uncertainty hinders our ability to maximally exploit these systems, identify knowledge gaps, and establish effective new model systems. Here, we borrow a definition of model systems from the biomolecular sciences to assess how EEID researchers are (and are not) using 10 key model systems. According to this definition, model systems in EEID are not being used to their fullest and, in fact, cannot even be considered model systems. Research using these systems consistently addresses only two of the three fundamental processes that underlie disease dynamics-transmission and disease, but not recovery. Furthermore, studies tend to focus on only a few scales of biological organization that matter for disease ecology and evolution. Moreover, the field lacks an infrastructure to perform comparative analyses. We aim to begin a discussion of what we want from model systems, which would further progress toward a thorough, holistic understanding of EEID.

Affinity Purification-Mass Spectrometry Identifies a Novel Interaction between a Polerovirus and a Conserved Innate Immunity Aphid Protein that Regulates Transmission Efficiency.

The vast majority of plant viruses are transmitted by insect vectors, with many crucial aspects of the transmission process being mediated by key protein-protein interactions. Still, very few vector proteins interacting with viruses have been identified and functionally characterized. Potato leafroll virus (PLRV) is transmitted most efficiently by Myzus persicae, the green peach aphid, in a circulative, non-propagative manner. Using affinity purification coupled to high-resolution mass spectrometry (AP-MS), we identified 11 proteins from M. persicaedisplaying a high probability of interaction with PLRV and an additional 23 vector proteins with medium confidence interaction scores. Three of these aphid proteins were confirmed to directly interact with the structural proteins of PLRV and other luteovirid species via yeast two-hybrid. Immunolocalization of one of these direct PLRV-interacting proteins, an orthologue of the human innate immunity protein complement component 1 Q subcomponent-binding protein (C1QBP), shows that MpC1QBP partially co-localizes with PLRV in cytoplasmic puncta and along the periphery of aphid gut epithelial cells. Artificial diet delivery to aphids of a chemical inhibitor of C1QBP leads to increased PLRV acquisition by aphids and subsequently increased titer in inoculated plants, supporting a role for C1QBP in the acquisition and transmission efficiency of PLRV by M. persicae. This study presents the first use of AP-MS for the in vivo isolation of a functionally relevant insect vector-virus protein complex. MS data are available from ProteomeXchange.org using the project identifier PXD022167.

Developing a new model system for potato genetics by androgenesis.

High heterozygosity and tetrasomic inheritance complicate studies of asexually propagated polyploids, such as potato. Reverse genetics approaches, especially mutant library construction, can be an ideal choice if a proper mutagenesis genotype is available. Here, we aimed to generate a model system for potato research using anther cultures of Solanum verrucosum, a self-compatible diploid potato with strong late blight resistance. Six of the 23 regenerants obtained (SVA4, SVA7, SVA22, SVA23, SVA32, and SVA33) were diploids, and their homozygosity was estimated to be >99.99% with 22 polymorphic InDel makers. Two lines-SVA4 and SVA32-had reduced stature (plant height ≤80 cm), high seed yield (>1,000 seeds/plant), and good tuber set (>30 tubers/plant). We further confirmed the full homozygosity of SVA4 and SVA32 using whole-genome resequencing. These two regenerants possess all the characteristics of a model plant: diploidy, 100% homozygosity, self-compatibility, and amenability to transgenesis. Thus, we have successfully generated two lines, SVA4 and SVA32, which can potentially be used for mutagenesis and as model plants to rejuvenate current methods of conducting potato research.

Investigation on the mitigation effects of furfuryl alcohol and 5-hydroxymethylfurfural and their carboxylic acid derivatives in coffee and coffee-related model systems.

The mitigation of furfuryl alcohol, 5-hydroxymethylfurfural, 2-furoic acid, and 5-hydroxymethyl 2-furoic acid was conducted in two dry model systems mimicking coffee and an actual coffee system by incorporating 14 chemicals, that are categorized to phenolic acids, flavonoids, non-phenolic antioxidants, and non-antioxidant agents. Mitigation effects were determined as the decrease in the levels of the studied furan derivatives after the systems went through a controlled roasting process. Strong mitigation effects in the dry model systems were observed after the application of phenolic acids, quinic acid or EDTA. The mitigation effects of phenolic acids and flavonoids depended on the number and availability of phenolic hydroxyl groups. Certain agents exhibited a furan derivative-specific reducing effect while most of them showed a generalized effect. The mitigation efficacy decreased with the increasing complexity of the tested systems. In the coffee system, mitigation effects were almost completely lost in comparison with dry model systems. Still, taurine and sodium sulfite exerted the strongest mitigation effect in the coffee system.

Hypolipidemic and anti-inflammatory properties of phenolic rich Butia odorata fruit extract: potential involvement of paraoxonase activity.

Aim: This study investigated the effects of polar Butia odorata fruit extract on metabolic, inflammatory, and oxidative stress parameters in rats submitted to a hyperlipidaemia condition induced by tyloxapol.Methods: Animals were divided into 3 groups: saline, saline plus tyloxapol, and B. odorata extract plus tyloxapol. Animals were treated for 15 days with a saline solution or B. odorata fruit extract and after hyperlipidaemia was induced by tyloxapol.Results: Treatment with B. odorata extract reduced serum triglyceride, total cholesterol, C-reactive protein, and adenosine deaminase and butyrylcholinesterase activities when compared to the tyloxapol group. HDL-cholesterol and paraoxonase 1 activity were higher in B. odorata extract treated animals when compared to tyloxapol-treated animals. No differences were observed in hepatic oxidative stress parameters. Phenolic compounds present in B. odorata fruit extract were identified and quantified by LC-MS/MS.Conclusion: These findings indicated that phenolic rich B. odorata extract has hypolipidemic and anti-inflammatory effects in hyperlipidemic rats.

Effect of stabilizing agents on characteristics, antioxidant activities and stability of liposome loaded with hydrolyzed collagen from defatted Asian sea bass skin.

Poor stability of fish hydrolyzed collagen (HC) hampers its applications, especially as food ingredients. The use of liposome as a vesicle can be a potential means to enhance bioactivities and stability of HC. HC from defatted Asian sea bass skin at different levels (0.25%-2%, w/v) were loaded into liposomes prepared from soy phosphatidylcholine (SPC) with various stabilizers (cholesterol (CHO) or glycerol (GLY)). The highest encapsulation efficiency (EE) was found in SPC-CHO-0.5%HC (P < 0.05) (85.42%), while liposome stabilized with GLY had the highest EE (74.54%) for SPC-GLY-0.25%HC (P < 0.05). After lyophilization, SPC-CHO-0.5%HC had higher EE than SPC-GLY-0.25%HC (P < 0.05). Increasing particle size and decreasing negative surface charge were found for both lyophilized samples. Lyophilized SPC-CHO-0.5%HC exhibited higher stability than lyophilized SPC-GLY-0.25%HC during storage at 25 °C for 28 days. Also, higher antioxidant activities in gastrointestinal track model system was found for SPC-CHO-0.5%HC. Thus, SPC-CHO liposome could be used as a promising carrier of HC.

Plant derived ingredients rich in nitrates or phenolics for protection of pork against protein oxidation.

A pork model system containg phenolic extracts (citrus, rosemary, and acerola), traditional Spanish food ingredients (paprika, garlic, and oregano), or natural nitrate sources (beet, lettuce, arugula, spinach, chard, celery, and watercress) were oxidized by an hydrophilic (OXHydro, 2,2'-azobis(2-amidinopropane)-dihydrochloride; AAPH) or lipophilic (OXLip, 2,2'-azobis(2,4-dimethylvaleronitrile; AMVN) radical initiator. Citrus as well as lettuce and spinach protected almost fully against protein thiol loss and showed efficient radical scavenging activity as determined by ESR spectroscopy in both oxidizing systems. Rosemary was an efficient radical scavenger in both systems, but behaved as a prooxidant on thiols in the OXHydro system. Acerola was also found to be prooxidative as determined by increased radical signal intensity especially in the OXLip system, assigned to high concentration of ascorbate in the extract. Natural nitrate sources, especially lettuce and spinach, are accordingly potential substitutes for synthetic phenolic antioxidants protecting against protein thiol oxidation and radical formation in pork.

Promoting Model Systems of Microbiota-Medicinal Plant Interactions.

The role of the interaction(s) between medicinal plants (MPs) and their endophytes (bacterial microbiome) in the production of bioactive compounds (BCs) with therapeutic properties is emerging. Here, we propose Echinacea purpurea (L.) Moench as a new model to reveal the intimate crosstalk between MPs and bacterial endophytes, aiming to discover (new) BCs.

Lipid oxidation inhibition capacity of plant extracts and powders in a processed meat model system.

A meat model system was used for screening lipid oxidation inhibiting capacity of diverse horticultural plant materials. In the model, heme-containing sarcoplasmic proteins from the meat water-phase were homogenized with linoleic acid and thiobarbituric reactive substances (TBARS) were measured. 23 Plant materials were investigated at three high (50, 100, and 200 ppm) concentrations and five plant extracts were tested at three low (5, 10, and 20 ppm) concentrations over time. In the high concentration sets, summer savory freeze-dried powder, beetroot leaves extracted with 50% ethanol, and an olive polyphenol powder extracted from wastewater, inhibited oxidation the most effectively. After two weeks and at 200 ppm concentration, oxidation was reduced to 17.2%, 16.6% and 13.5% of the blank sample with no added antioxidants respectively. In the low concentration set, spray dried rhubarb juice inhibited oxidation the most after two weeks at 5 ppm where oxidation was reduced to 68.3% of the blank sample with no added antioxidants.

Emerging organoid models: leaping forward in cancer research.

Cancer heterogeneity is regarded as the main reason for the failure of conventional cancer therapy. The ability to reconstruct intra- and interpatient heterogeneity in cancer models is crucial for understanding cancer biology as well as for developing personalized anti-cancer therapy. Cancer organoids represent an emerging approach for creating patient-derived in vitro cancer models that closely recapitulate the pathophysiological features of natural tumorigenesis and metastasis. Meanwhile, cancer organoids have recently been utilized in the discovery of personalized anti-cancer therapy and prognostic biomarkers. Further, the synergistic combination of cancer organoids with organ-on-a-chip and 3D bioprinting presents a new avenue in the development of more sophisticated and optimized model systems to recapitulate complex cancer-stroma or multiorgan metastasis. Here, we summarize the recent advances in cancer organoids from a perspective of the in vitro emulation of natural cancer evolution and the applications in personalized cancer theranostics. We also discuss the challenges and trends in reconstructing more comprehensive cancer models for basic and clinical cancer research.

A combination of two novel VARS2 variants causes a mitochondrial disorder associated with failure to thrive and pulmonary hypertension.

The VARS2 gene encodes a mitochondrial valyl-transfer RNA synthetase which is used in mitochondrial translation. To date, several patients with VARS2 pathogenic variants have been described in the literature. These patients have features of lactic acidosis with encephalomyopathy. We present a case of an infant with lactic acidosis, failure to thrive, and severe primary pulmonary hypertension who was found to be a compound heterozygote for two novel VARS2 variants (c.1940C>T, p.(Thr647Met) and c.2318G>A, p.(Arg773Gln)). The patient was treated with vitamin supplements and a carbohydrate-restricted diet. The lactic acidosis and failure to thrive resolved, and he showed good growth and development. Functional studies and molecular analysis employed a yeast model system and the VAS1 gene (yeast homolog of VARS2). VAS1 genes harboring either one of two mutations corresponding to the two novel variants in the VARS2 gene, exhibited partially reduced function in haploid yeast strains. A combination of both VAS1 variant alleles in a diploid yeast cell exhibited a more significant decrease in oxidative metabolism-dependent growth and in the oxygen consumption rate (reminiscent of the patient who carries two mutant VARS2 alleles). Our results demonstrate the pathogenicity of the biallellic novel VARS2 variants. KEY MESSAGES: • A case of an infant who is a compound heterozygote for two novel VARS2 variants. • This infant displayed lactic acidosis, failure to thrive, and pulmonary hypertension. • Treatment of the patient with a carbohydrate-restricted diet resulted in good growth and development. • Studies with the homologous yeast VAS1 gene showed reduced function of corresponding single mutant in haploid yeast strains. • A combination of both VAS1 variant alleles in diploid yeast exhibited a more significant decrease in function, thereby confirming the pathogenicity of the biallellic novel VARS2 variants.

Mate extract is superior to green tea extract in the protection against chicken meat protein thiol oxidation.

Water soluble caffeic acid derivatives in aqueous extracts of mate (Ilex paraguariensis) showed a direct dose-dependent response, protecting protein thiols in a chicken breast meat model system when oxidation was initiated by a lipophilic radical initiator (2,2'-azobis(2,4-dimethylvaleronitrile; AMVN). In contrast, an inverse dose-dependent response was obtained when initiated by a hydrophilic radical initiator (2,2'-azobis(2-amidinopropane)dihydrochloride; AAPH), pointing toward a mechanism, where a specific concentration of water-soluble polyphenol yields optimum protection. Optimal concentrations of mate extract for the protection of thiols against radicals initiated in the lipid phase (AMVN) or in the aqueous phase (AAPH) were 0.1-0.5% and 0.01-0.1%, respectively. Green tea (Camellia sinensis) extract showed a pro-oxidative effect involving quinones from oxidation of pyrogallol-type catechins (epigallocatechin-3-gallate (EGCG), gallocatechin-3-gallate (GCG), and epicatechin-3-gallate (ECG)) and not the catechol-type catechins (catechin and epicatechin).

Aspergillus flavus as a Model System to Test the Biological Activity of Botanicals: An Example on Citrullus colocynthis L. Schrad. Organic Extracts.

Citrullus colocynthis L. Schrader is an annual plant belonging to the Cucurbitaceae family, widely distributed in the desert areas of the Mediterranean basin. Many pharmacological properties (anti-inflammatory, anti-diabetic, analgesic, anti-epileptic) are ascribed to different organs of this plant; extracts and derivatives of C. colocynthis are used in folk Berber medicine for the treatment of numerous diseases-such as rheumatism arthritis, hypertension bronchitis, mastitis, and even cancer. Clinical studies aimed at confirming the chemical and biological bases of pharmacological activity assigned to many plant/herb extracts used in folk medicine often rely on results obtained from laboratory preliminary tests. We investigated the biological activity of some C. colocynthis stem, leaf, and root extracts on the mycotoxigenic and phytopathogenic fungus Aspergillus flavus, testing a possible correlation between the inhibitory effect on aflatoxin biosynthesis, the phytochemical composition of extracts, and their in vitro antioxidant capacities.

Resolving structure and function of metaorganisms through a holistic framework combining reductionist and integrative approaches.

Current research highlights the importance of associated microbes in contributing to the functioning, health, and even adaptation of their animal, plant, and fungal hosts. As such, we are witnessing a shift in research that moves away from focusing on the eukaryotic host sensu stricto to research into the complex conglomerate of the host and its associated microorganisms (i.e., microbial eukaryotes, archaea, bacteria, and viruses), the so-called metaorganism, as the biological entity. While recent research supports and encourages the adoption of such an integrative view, it must be understood that microorganisms are not involved in all host processes and not all associated microorganisms are functionally important. As such, our intention here is to provide a critical review and evaluation of perspectives and limitations relevant to studying organisms in a metaorganism framework and the functional toolbox available to do so. We note that marker gene-guided approaches that primarily characterize microbial diversity are a first step in delineating associated microbes but are not sufficient to establish proof of their functional relevance. More sophisticated tools and experiments are necessary to reveal the specific functions of associated microbes. This can be accomplished through the study of metaorganisms in less complex environments, the targeted manipulation of microbial associates, or work at the mechanistic level with the toolbox available in model systems. We conclude that the metaorganism framework is a powerful new concept to help provide answers to longstanding biological questions such as the evolution and ecology of organismal complexity and the importance of organismal symbioses to ecosystem functioning. The intricacy of the metaorganism requires a holistic framework combining reductionist and integrative approaches to resolve the structure and function of its member species and to disclose the various roles that microorganisms play in the biology of their hosts.

Antidepressive effects of a chemically characterized maqui berry extract (Aristotelia chilensis (molina) stuntz) in a mouse model of Post-stroke depression.

Mood disorders occur in 30% of stroke patients, and of these post-stroke depression (PSD) is the most significant. This study aimed to evaluate the antidepressive-like effects and in vivo antioxidant activity of a chemically characterized maqui berry (Aristotelia chilensis (Molina) Stuntz) extract obtained from an optimized extraction method, on a murine PSD model. The extraction process was optimized to maximize anthocyanin content, and the phytochemical profile of the extract was evaluated using a multi-methodological approach including a liquid chromatographic method coupled with mass spectrometry and nuclear magnetic resonance spectroscopy. The antidepressive-like activity was investigated through despair swimming and tail suspension tests. The in vivo antioxidant activity was evaluated in mouse brain tissue by measuring the activity of antioxidant enzymes and lipid peroxidation products. A number of compounds have been first identified in maqui berry here, including malvidin-glucoside, GABA, choline and trigonelline. Moreover, the results showed that the antidepressive-like activity exerted by the extract, which was found to restore normal mouse behavior in both despair swimming and tail suspension tests, could be linked to its antioxidant activity, leading to the conclusion that maqui berries might be useful for supporting pharmacological therapy of PSD by modulating oxidative stress.

Stability of vitamin D3 and vitamin D2 in oil, fish and mushrooms after household cooking.

Information on the retention of vitamin D in food following household cooking is scarce. So far the retention of its metabolites vitamin D3, vitamin D2, and 25-hydroxyvitamin D3 has shown that the type of food and the cooking method are the essential determinants, and there is no significant difference between the metabolites. We investigated the retention of vitamin D3 and vitamin D2 in sunflower oil, vitamin D3 in rainbow trout, and vitamin D2 in button mushrooms. The investigated cooking methods were boiling at different pH, steam cooking, microwave cooking, pan-frying, and oven baking. There was no difference between the retention of vitamin D3 and vitamin D2 added to sunflower oil, which ranged from 70 to 99%. In rainbow trout, the retention of vitamin D3 at 85-114% was not significantly different from 100%, except for panfrying at 85%. However, the retention of vitamin D2 in mushrooms at 62-88% was significantly different from 100% (p ≤ 0.05).

Pseudomonas aeruginosa Aggregate Formation in an Alginate Bead Model System Exhibits In Vivo-Like Characteristics.

Alginate beads represent a simple and highly reproducible in vitro model system for diffusion-limited bacterial growth. In this study, alginate beads were inoculated with Pseudomonas aeruginosa and followed for up to 72 h. Confocal microscopy revealed that P. aeruginosa formed dense clusters similar in size to in vivo aggregates observed ex vivo in cystic fibrosis lungs and chronic wounds. Bacterial aggregates primarily grew in the bead periphery and decreased in size and abundance toward the center of the bead. Microsensor measurements showed that the O2 concentration decreased rapidly and reached anoxia ∼100 µm below the alginate bead surface. This gradient was relieved in beads supplemented with NO3- as an alternative electron acceptor allowing for deeper growth into the beads. A comparison of gene expression profiles between planktonic and alginate-encapsulated P. aeruginosa confirmed that the bacteria experienced hypoxic and anoxic growth conditions. Furthermore, alginate-encapsulated P. aeruginosa exhibited a lower respiration rate than the planktonic counterpart and showed a high tolerance toward antibiotics. The inoculation and growth of P. aeruginosa in alginate beads represent a simple and flexible in vivo-like biofilm model system, wherein bacterial growth exhibits central features of in vivo biofilms. This was observed by the formation of small cell aggregates in a secondary matrix with O2-limited growth, which was alleviated by the addition of NO3- as an alternative electron acceptor, and by reduced respiration rates, as well as an enhanced tolerance to antibiotic treatment.IMPORTANCEPseudomonas aeruginosa has been studied intensively for decades due to its involvement in chronic infections, such as cystic fibrosis and chronic wounds, where it forms biofilms. Much research has been dedicated to biofilm formation on surfaces; however, in chronic infections, most biofilms form small aggregates of cells not attached to a surface, but embedded in host material. In this study, bacteria were encapsulated in small alginate beads and formed aggregates similar to what is observed in chronic bacterial infections. Our findings show that aggregates are exposed to steep oxygen gradients, with zones of oxygen depletion, and that nitrate may serve as an alternative to oxygen, enabling growth in oxygen-depleted zones. This is important, as slow growth under low-oxygen conditions may render the bacteria tolerant toward antibiotics. This model provides an alternative to surface biofilm models and adds to the comprehension that biofilms do not depend on a surface for formation.

Using Xenopus to understand human disease and developmental disorders.

Model animals are crucial to biomedical research. Among the commonly used model animals, the amphibian, Xenopus, has had tremendous impact because of its unique experimental advantages, cost effectiveness, and close evolutionary relationship with mammals as a tetrapod. Over the past 50 years, the use of Xenopus has made possible many fundamental contributions to biomedicine, and it is a cornerstone of research in cell biology, developmental biology, evolutionary biology, immunology, molecular biology, neurobiology, and physiology. The prospects for Xenopus as an experimental system are excellent: Xenopus is uniquely well-suited for many contemporary approaches used to study fundamental biological and disease mechanisms. Moreover, recent advances in high throughput DNA sequencing, genome editing, proteomics, and pharmacological screening are easily applicable in Xenopus, enabling rapid functional genomics and human disease modeling at a systems level.

Antibacterial Activity of Indian Borage (Plectranthus amboinicus Benth) Leaf Extracts in Food Systems andAgainst Natural Microflora in Chicken Meat.

The ability of acetone and ethyl acetate extracts of the leaves of a traditional Indian medicinal plant, Indian borage (Plectranthus amboinicus Benth) to prevent spoilage of artificially inoculated model food systems (cabbage and papaya) and natural microflora of chicken meat was evaluated. These extracts were able to reduce the bacterial counts in all food systems; however, the effective concentration varied with the complexity of the system (cabbage